U.S. patent application number 16/643807 was filed with the patent office on 2020-07-30 for electromagnetic valve identification device and control unit including same.
This patent application is currently assigned to KAWASAKI JUKOGYO KABUSHIKI KAISHA. The applicant listed for this patent is KAWASAKI JUKOGYO KABUSHIKI KAISHA. Invention is credited to Akihiro KONDO, Yuki NAKAYAMA, Ryuji SAKAI.
Application Number | 20200240115 16/643807 |
Document ID | 20200240115 / US20200240115 |
Family ID | 1000004768398 |
Filed Date | 2020-07-30 |
Patent Application | download [pdf] |
![](/patent/app/20200240115/US20200240115A1-20200730-D00000.png)
![](/patent/app/20200240115/US20200240115A1-20200730-D00001.png)
![](/patent/app/20200240115/US20200240115A1-20200730-D00002.png)
![](/patent/app/20200240115/US20200240115A1-20200730-D00003.png)
![](/patent/app/20200240115/US20200240115A1-20200730-D00004.png)
![](/patent/app/20200240115/US20200240115A1-20200730-D00005.png)
![](/patent/app/20200240115/US20200240115A1-20200730-D00006.png)
![](/patent/app/20200240115/US20200240115A1-20200730-D00007.png)
United States Patent
Application |
20200240115 |
Kind Code |
A1 |
KONDO; Akihiro ; et
al. |
July 30, 2020 |
ELECTROMAGNETIC VALVE IDENTIFICATION DEVICE AND CONTROL UNIT
INCLUDING SAME
Abstract
An electromagnetic valve identification device configured to
realize individual identification of an electromagnetic valve while
suppressing an increase in manufacturing cost. The electromagnetic
valve identification device is mounted on an industrial machine,
such as a construction machine or an industrial vehicle, configured
to move a hydraulic actuator to perform work. The electromagnetic
valve identification device includes: an inductance measuring
circuit configured to supply an alternating current to a solenoid
of an electromagnetic valve of a hydraulic device, the hydraulic
device being configured to supply pressure oil to the hydraulic
actuator to operate the hydraulic actuator; a calculating portion
configured to calculate an inductance of the solenoid based on the
alternating current supplied to the solenoid by the inductance
measuring circuit; and a storage portion configured to store the
calculated inductance of the solenoid as individual identification
information of the electromagnetic valve.
Inventors: |
KONDO; Akihiro; (Kobe-shi,
JP) ; SAKAI; Ryuji; (Kakogawa-shi, JP) ;
NAKAYAMA; Yuki; (Amagasaki-shi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
KAWASAKI JUKOGYO KABUSHIKI KAISHA |
Kobe-shi, Hyogo |
|
JP |
|
|
Assignee: |
KAWASAKI JUKOGYO KABUSHIKI
KAISHA
Kobe-shi, Hyogo
JP
|
Family ID: |
1000004768398 |
Appl. No.: |
16/643807 |
Filed: |
August 22, 2018 |
PCT Filed: |
August 22, 2018 |
PCT NO: |
PCT/JP2018/030961 |
371 Date: |
March 2, 2020 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
E02F 9/2296 20130101;
F15B 2211/6316 20130101; E02F 9/2004 20130101; E02F 9/2221
20130101; F15B 2211/6651 20130101; E02F 9/2285 20130101; E02F
9/2246 20130101 |
International
Class: |
E02F 9/22 20060101
E02F009/22 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 31, 2017 |
JP |
2017-167464 |
Claims
1. An electromagnetic valve identification device mounted on an
industrial machine, such as a construction machine or an industrial
vehicle, configured to move a hydraulic actuator to perform work,
the electromagnetic valve identification device comprising: an
inductance measuring circuit configured to supply an alternating
current to a solenoid of an electromagnetic valve of a hydraulic
device, the hydraulic device being configured to supply pressure
oil to the hydraulic actuator to operate the hydraulic actuator; a
calculating portion configured to calculate an inductance of the
solenoid based on the alternating current supplied to the solenoid
by the inductance measuring circuit; and a storage portion
configured to store the calculated inductance of the solenoid as
individual identification information of the electromagnetic
valve.
2. The electromagnetic valve identification device according to
claim 1, further comprising a replacement determining portion
configured to determine whether or not the electromagnetic valve
has been replaced, based on a determination criterion in which
whether or not the electromagnetic valve has been replaced is
determined by using the inductance calculated by the calculating
portion.
3. The electromagnetic valve identification device according to
claim 2, wherein: the determination criterion includes whether or
not a reference inductance of the solenoid and an actually measured
inductance of the solenoid are different from each other, the
reference inductance being calculated by the calculating portion
and stored in the storage portion in advance, the actually measured
inductance being calculated by the calculating portion; and when
the actually measured inductance is different from the reference
inductance, the replacement determining portion determines that the
electromagnetic valve has been replaced.
4. The electromagnetic valve identification device according to
claim 3, wherein: when a predetermined reference value setting
condition is satisfied, the calculating portion calculates the
reference inductance of the solenoid; and the storage portion
stores the reference inductance calculated by the calculating
portion.
5. The electromagnetic valve identification device according to
claim 2, wherein: the determination criterion includes whether or
not the actually measured inductance calculated by the calculating
portion falls within a predetermined allowable range; and when the
actually measured inductance falls outside the allowable range, the
replacement determining portion determines that the electromagnetic
valve has been replaced.
6. The electromagnetic valve identification device according to
claim 2, further comprising a resistance measuring portion
configured to supply a direct current to the solenoid and measure a
resistance value of the solenoid, wherein: the determination
criterion includes whether or not a reference resistance value of
the solenoid and an actually measured resistance value of the
solenoid are different from each other, the reference resistance
value being measured by the resistance measuring portion in
advance, the actually measured resistance value being measured by
the resistance measuring portion; and the replacement determining
portion compares the actually measured resistance value with the
reference resistance value and determines whether or not the
electromagnetic valve has been replaced.
7. An electromagnetic valve identification device mounted on an
industrial machine, such as a construction machine or an industrial
vehicle, configured to move a hydraulic actuator to perform work,
the electromagnetic valve identification device comprising: a
resistance measuring portion configured to supply a direct current
to a solenoid of an electromagnetic valve of a hydraulic device and
measure a resistance value of the solenoid, the hydraulic device
being configured to supply pressure oil to the hydraulic actuator
to operate the hydraulic actuator; and a replacement determining
portion configured to determine whether or not the electromagnetic
valve has been replaced, based on a determination criterion in
which whether or not the electromagnetic valve has been replaced is
determined by using the resistance value measured by the resistance
measuring portion.
8. The electromagnetic valve identification device according to
claim 7, wherein the determination criterion includes whether or
not a reference resistance value of the solenoid and an actually
measured resistance value of the solenoid are different from each
other, the reference resistance value being measured by the
resistance measuring portion in advance, the actually measured
resistance value being measured by the resistance measuring
portion.
9. A control unit comprising: the electromagnetic valve
identification device according to claim 2; and a control device
mounted on the industrial vehicle and configured to supply a
current to the solenoid of the electromagnetic valve to control an
operation of the electromagnetic valve, wherein the control device
is configured to restrict the operation of the electromagnetic
valve when the replacement determining portion determines that the
electromagnetic valve has been replaced.
Description
TECHNICAL FIELD
[0001] The present invention relates to an electromagnetic valve
identification device configured to perform individual
identification of an electromagnetic valve mounted on an industrial
machine, such as a construction machine or an industrial vehicle,
and a control unit including the electromagnetic valve
identification device.
BACKGROUND ART
[0002] Construction machines (such as hydraulic excavators and
wheel loaders) and travelable industrial vehicles (such as
forklifts) can perform various types of work by moving attachments
(such as buckets and forks). According to the construction machines
and industrial vehicles having such function, the attachments are
moved by operating hydraulic actuators (such as hydraulic cylinders
and hydraulic motors). The hydraulic actuators are driven by being
supplied with operating oil. The industrial vehicles include
hydraulic devices configured to supply the operating oil to the
hydraulic actuators. In order to change a tilting angle of a
hydraulic pump and move a spool of a flow control valve, the
hydraulic device includes a plurality of electromagnetic
valves.
[0003] As with other devices, the electromagnetic valve may be
required to be replaced due to breakdown or the like and is
actually replaced once in a while. Typically, the electromagnetic
valve of the hydraulic device is replaced with a proper hydraulic
device, and with this, the function of the hydraulic device is
secured. Therefore, when replacing the electromagnetic valve, it is
preferable to use a proper product having the same function and
quality as the electromagnetic valve equipped in a construction
machine or industrial vehicle when the construction machine or
industrial vehicle is assembled and manufactured. However,
actually, electromagnetic valves that are improper products having
low quality are used as replacement parts in some cases. In such
cases, the hydraulic device cannot exert a desired function, and in
the worst case, the hydraulic device and various devices of the
industrial vehicle may be damaged. In order to prevent the use of
the improper product at the time of replacement, for example,
devices of PTLs 1 and 2 are known.
[0004] According to an identification device of PTL 1, IC chips are
attached to replaceable parts. Then, the identification device
detects information stored in the IC chips and determines whether
the replaceable parts are genuine products (proper products) or
counterfeit products (improper products). Further, according to an
improper part use prevention system of PTL 2, part IDs are attached
to replaceable parts, and the part IDs are input through an input
unit. The input part IDs are transmitted to a data server through a
wireless communication network, and whether or not the input part
IDs are part IDs of unused parts is determined. Thus, the improper
products are prevented from being used.
CITATION LIST
Patent Literature
[0005] PTL 1: Japanese Patent No. 4399524
[0006] PTL 2: Japanese Laid-Open Patent Application Publication No.
2016-98528
SUMMARY OF INVENTION
Technical Problem
[0007] According to the identification device of PTL 1, the
individual identification of the replaceable parts is performed
based on the information stored in the IC chips, and therefore, the
IC chips have to be attached to the respective parts. In addition,
in order to perform the individual identification, sensors
configured to detect the information of the IC chips need to be
arranged at various places. Thus, the number of parts increases,
and this increases the manufacturing cost.
[0008] According to the improper part use prevention system of PTL
2, the individual identification of the replaceable parts is
performed by attaching the part IDs to the respective replaceable
parts. The individual identification needs to be performed by
transmitting the part IDs to the data server. Therefore, a wireless
communication device and the data server are necessary, and this
increases the manufacturing cost.
[0009] An object of the present invention is to provide an
electromagnetic valve identification device configured to perform
individual identification of an electromagnetic valve while
suppressing a manufacturing cost.
Solution to Problem
[0010] An electromagnetic valve identification device according to
the present invention is an electromagnetic valve identification
device mounted on an industrial machine, such as a construction
machine or an industrial vehicle, configured to move a hydraulic
actuator to perform work. The electromagnetic valve identification
device includes: an inductance measuring circuit configured to
supply an alternating current to a solenoid of an electromagnetic
valve of a hydraulic device, the hydraulic device being configured
to supply pressure oil to the hydraulic actuator to operate the
hydraulic actuator; a calculating portion configured to calculate
an inductance of the solenoid based on the alternating current
supplied to the solenoid by the inductance measuring circuit; and a
storage portion configured to store the calculated inductance of
the solenoid as individual identification information of the
electromagnetic valve.
[0011] According to the present invention, the inductance of the
solenoid of the electromagnetic valve is stored as the individual
identification information. Regarding the inductances of the
solenoids, the inductance of each solenoid has a specific value.
However, typically, even when solenoids are the same in winding
number and wire diameter as one another, the inductances of the
respective solenoids have different numerical values, i.e., the
inductances of the respective solenoids vary. Therefore, the
inductance of the solenoid of the electromagnetic valve can be used
as the individual identification information of the electromagnetic
valve. To be specific, the individual identification of the
electromagnetic valve and a part including the electromagnetic
valve can be performed by mounting such electromagnetic valve
identification device on the industrial vehicle. Therefore, it is
unnecessary to attach IC chips to electromagnetic valves and parts
including the electromagnetic valves mounted on industrial vehicles
or attach IDs to electromagnetic valves and parts including the
electromagnetic valves mounted on industrial vehicles to manage the
electromagnetic valves and the parts, in order to perform the
individual identification of the electromagnetic valves. Thus, the
manufacturing cost can be suppressed.
[0012] In the above invention, the electromagnetic valve
identification device may further include a replacement determining
portion configured to determine whether or not the electromagnetic
valve has been replaced, based on a determination criterion in
which whether or not the electromagnetic valve has been replaced is
determined by using the inductance calculated by the calculating
portion.
[0013] According to the above configuration, whether or not the
electromagnetic valve has been replaced can be determined by using
the inductance of the solenoid, i.e., the individual identification
information. Therefore, whether or not the electromagnetic valve
has been replaced can be determined by a simple configuration
without attaching IC chips to electromagnetic valves and parts
including the electromagnetic valves mounted on industrial vehicles
or attaching IDs to electromagnetic valves and parts including the
electromagnetic valves mounted on industrial vehicles to manage the
electromagnetic valves and the parts.
[0014] In the above invention, the determination criterion may
include whether or not a reference inductance of the solenoid and
an actually measured inductance of the solenoid are different from
each other, the reference inductance being calculated by the
calculating portion and stored in the storage portion in advance,
the actually measured inductance being calculated by the
calculating portion, and when the actually measured inductance is
different from the reference inductance, the replacement
determining portion may determine that the electromagnetic valve
has been replaced.
[0015] According to the above configuration, whether or not the
electromagnetic valve having the same inductance is being
continuously mounted can be determined, i.e., whether or not the
same electromagnetic valve is being continuously mounted can be
determined. When the same electromagnetic valve is not being
continuously mounted, it can be determined that the electromagnetic
valve has been replaced at a certain time point. Therefore, whether
or not the replacement work has been performed can be surely
determined.
[0016] In the above invention, when a predetermined reference value
setting condition is satisfied, the calculating portion may
calculate the reference inductance of the solenoid, and the storage
portion may store the reference inductance calculated by the
calculating portion.
[0017] According to the above configuration, when the reference
value setting condition is satisfied after the electromagnetic
valve has been replaced, the inductance of the replaced
electromagnetic valve can be newly stored as the reference
inductance. On the other hand, when the reference value setting
condition is not satisfied, the reference inductance cannot be
reset. Therefore, it is possible to prevent a case where the
reference inductance is freely changed, and the electromagnetic
valve is made to look as if it has not been replaced.
[0018] In the above invention, the determination criterion may
include whether or not the actually measured inductance calculated
by the calculating portion falls within a predetermined allowable
range, and when the actually measured inductance falls outside the
allowable value, the replacement determining portion may determine
that the electromagnetic valve has been replaced.
[0019] According to the above configuration, whether or not the
electromagnetic valve has been replaced can be determined based on
whether or not the inductance of the replaced electromagnetic
valve, i.e., the actually measured inductance falls outside the
allowable range. Therefore, it is possible to prevent a case where
an electromagnetic valve having an inductance that falls outside
the allowable range is adopted as a replacement part. It should be
noted that the allowable range is, for example, a range of
manufacturing error (tolerance) of electromagnetic valves (for
example, electromagnetic valves as proper products) that are not
the same as one another but can exert substantially the same
function. With this, the replacement of the electromagnetic valve
having the inductance that falls outside the allowable range can be
found, i.e., the replacement of the electromagnetic valve that is
an improper product, such as a counterfeit product, can be
found.
[0020] In the above invention, the electromagnetic valve
identification device may further include a resistance measuring
portion configured to supply a direct current to the solenoid and
measure a resistance value of the solenoid. The determination
criterion may include whether or not a reference resistance value
of the solenoid and an actually measured resistance value of the
solenoid are different from each other, the reference resistance
value being measured by the resistance measuring portion in
advance, the actually measured resistance value being measured by
the resistance measuring portion, and the replacement determining
portion may compare the actually measured resistance value with the
reference resistance value and determine whether or not the
electromagnetic valve has been replaced.
[0021] According to the above configuration, whether or not the
electromagnetic valve has been replaced can be determined based on
the resistance value of the solenoid of the electromagnetic valve.
When solenoids are the same in winding number and wire diameter as
one another, the resistance values of such solenoids vary less than
the inductances of the solenoids. Therefore, the type and the like
of the electromagnetic valve can be specified by comparing the
resistance value of the solenoid of the electromagnetic valve with
the reference resistance value. On this account, by using the
resistance value of the solenoid of the electromagnetic valve in
the individual identification together with the inductance of the
solenoid of the electromagnetic valve, the individual
identification of the electromagnetic valves and the parts
including the electromagnetic valves can be performed more
accurately.
[0022] An electromagnetic valve identification device according to
the present invention is an electromagnetic valve identification
device mounted on an industrial machine, such as a construction
machine or an industrial vehicle, configured to move a hydraulic
actuator to perform work. The electromagnetic valve identification
device includes: a resistance measuring portion configured to
supply a direct current to a solenoid of an electromagnetic valve
of a hydraulic device and measure a resistance value of the
solenoid, the hydraulic device being configured to supply pressure
oil to the hydraulic actuator to operate the hydraulic actuator;
and a replacement determining portion configured to determine
whether or not the electromagnetic valve has been replaced, based
on a determination criterion in which whether or not the
electromagnetic valve has been replaced is determined by using the
resistance value measured by the resistance measuring portion.
[0023] According to the present invention, whether or not the
electromagnetic valve has been replaced can be determined by using
the resistance of the solenoid, i.e., the individual identification
information. Therefore, whether or not the electromagnetic valve
has been replaced can be determined by a simple configuration
without attaching IC chips to electromagnetic valves and parts
including the electromagnetic valves mounted on industrial vehicles
or attaching IDs to electromagnetic valves and parts including the
electromagnetic valves mounted on industrial vehicles to manage the
electromagnetic valves and the parts. In addition, typically, the
above effects can be obtained only by changing software or control
logic without changing the hardware configuration of a conventional
control device. Further, the resistance value of the solenoid can
be detected by a smaller number of parts than the inductance of the
solenoid. Therefore, the determination based on the resistance is
lower in cost than the determination based on the inductance.
[0024] In the above invention, the determination criterion may
include whether or not a reference resistance value of the solenoid
and an actually measured resistance value of the solenoid are
different from each other, the reference resistance value being
measured by the resistance measuring portion in advance, the
actually measured resistance value being measured by the resistance
measuring portion.
[0025] According to the above configuration, whether or not the
electromagnetic valve has been replaced can be determined by
comparing the resistance values.
[0026] A control unit according to the present invention includes:
the above-described electromagnetic valve identification device;
and a control device mounted on the industrial vehicle and
configured to supply a current to the solenoid of the
electromagnetic valve to control an operation of the
electromagnetic valve. The control device is configured to restrict
the operation of the electromagnetic valve when the replacement
determining portion determines that the electromagnetic valve has
been replaced.
[0027] According to the above configuration, it is possible to
prevent the use of the hydraulic device whose function is made low
since, for example, the replaced electromagnetic valve is an
improper product, or the electromagnetic valve is replaced through
an improper method.
Advantageous Effects of Invention
[0028] According to the present invention, the individual
identification of the electromagnetic valve can be performed while
suppressing an increase in the manufacturing cost.
BRIEF DESCRIPTION OF DRAWINGS
[0029] FIG. 1 is a hydraulic circuit diagram showing the
configuration of a hydraulic device including a control unit
according to Embodiment 1 of the present invention.
[0030] FIG. 2 is a block diagram showing functional blocks of the
control unit of FIG. 1.
[0031] FIG. 3 is an electric circuit diagram showing the
configuration of an LCR measuring circuit included in the control
unit of FIG. 2.
[0032] FIG. 4 is a flow chart showing the procedure of individual
identification processing executed by the control unit shown in
FIG. 2.
[0033] FIG. 5 is a flow chart showing the procedure of reference
value measurement processing executed in a reference value
measurement mode of FIG. 4.
[0034] FIG. 6 is a flow chart showing the procedure of actually
measured value measurement processing executed in an actually
measured value measurement mode of FIG. 4.
[0035] FIG. 7 is a block diagram showing functional blocks of the
control unit of Embodiment 2.
DESCRIPTION OF EMBODIMENTS
[0036] Hereinafter, control units 1 and 1A according to Embodiments
1 and 2 of the present invention will be described with reference
to the drawings. It should be noted that directions stated in the
following description are used for convenience sake, and directions
and the like of components of the present invention are not
limited. Each of the control units 1 and 1A described below is just
one embodiment of the present invention. Therefore, the present
invention is not limited to the embodiments, and additions,
deletions, and modifications may be made within the scope of the
present invention.
[0037] Construction Machine and Industrial Vehicle
[0038] Construction machines and industrial vehicles as examples of
industrial machines perform various types of work by moving various
attachments. Examples of the construction machines include
hydraulic excavators, wheel loaders, cranes, skid steer loaders,
and aerial work platform vehicles, and examples of the industrial
vehicles include forklifts. These construction machines and
industrial vehicles can perform work, such as excavating work and
carrying work. For example, a hydraulic excavator includes a bucket
and performs excavation by the bucket. Further, the hydraulic
excavator includes a travelable vehicle body and can change an
excavation position and carry, for example, excavated sand by
making the vehicle body travel. In the hydraulic excavator
configured as above, the bucket is attached to the vehicle body
through a boom and an arm. The hydraulic excavator performs
excavating work by making the bucket, the boom, and the arm swing
in front, rear, upper, and lower directions. Further, the hydraulic
excavator makes the bucket, the boom, and the arm swing by
hydraulic cylinders.
[0039] The hydraulic cylinder that is one example of a hydraulic
actuator operates by being supplied with operating oil that is
pressure oil. To be specific, the hydraulic cylinder expands or
contracts in accordance with a flow direction of the operating oil
supplied thereto and operates at a speed corresponding to a flow
rate of the operating oil supplied thereto. As above, the hydraulic
cylinder is driven by the operating oil supplied thereto, and the
hydraulic excavator includes a hydraulic driving apparatus 2
configured to supply the operating oil to the hydraulic
cylinder.
[0040] Hydraulic Device
[0041] As shown in FIG. 1, the hydraulic driving apparatus 2 mainly
includes a hydraulic pump device 11, a plurality of flow rate
control devices 12, and a bleed-off valve 13. It should be noted
that FIG. 1 shows only one flow rate control device 12 located at a
most upstream side among the plurality of flow rate control devices
12, and does not show the other flow rate control devices 12. The
hydraulic pump device 11 is configured to discharge the operating
oil to supply the operating oil to the hydraulic actuator. The
hydraulic pump device 11 includes a hydraulic pump 21, a regulator
22, and an electromagnetic proportional valve 23. The hydraulic
pump 21 is coupled to a driving source, such as an engine (not
shown), and is rotated by the driving source. By this rotation, the
hydraulic pump 21 sucks the operating oil from a tank 15 and
discharges the operating oil to a main passage 16. The hydraulic
pump 21 is a variable displacement swash plate pump and includes a
swash plate 21a. A tilting angle of the swash plate 21a is
changeable, and a discharge volume of the hydraulic pump 21 changes
by changing the tilting angle. The regulator 22 is attached to the
swash plate 21a having such function. The electromagnetic
proportional valve 23 is attached to the regulator 22. The
regulator 22 is formed integrally with a casing of the hydraulic
pump 21.
[0042] The regulator 22 is a mechanism configured to change the
tilting angle of the swash plate 21a and includes a servo piston
(not shown). The servo piston is coupled to the swash plate 21a and
can reciprocate along an axis thereof. The servo piston configured
as above can change the tilting angle of the swash plate 21a by
changing a position thereof. Further, the servo piston changes the
position thereof in accordance with pilot pressure p input thereto.
The electromagnetic proportional valve 23 configured to apply the
pilot pressure p to the servo piston is connected to the regulator
22.
[0043] The electromagnetic proportional valve 23 is a so-called
direct proportion type electromagnetic valve and outputs pilot oil
having pressure corresponding to a current (discharge volume
command current) input thereto. More specifically, the
electromagnetic proportional valve 23 is connected to the regulator
22, the tank 15, and a pilot pump (not shown). The electromagnetic
proportional valve 23 includes a solenoid 23a. In accordance with a
current supplied to the solenoid 23a, the electromagnetic
proportional valve 23 adjusts a connection status between the
regulator 22 and the tank 15, an opening degree therebetween, a
connection status between the regulator 22 and the pilot pump, and
an opening degree therebetween. To be specific, when a current is
not supplied to the solenoid 23a of the electromagnetic
proportional valve 23, the regulator 22 and the tank 15 are
connected to each other. On the other hand, when a current is
supplied to the solenoid 23a, communication between the regulator
22 and the tank 15 is closed, and the regulator 22 and the pilot
pump are connected to each other. Further, in accordance with a
current supplied to the solenoid 23a, the opening degree between
the regulator 22 and the pilot pump increases, and the opening
degree between the regulator 22 and the tank decreases.
[0044] The electromagnetic proportional valve 23 configured as
above outputs to the regulator 22 the pilot pressure p
corresponding to the current supplied to the solenoid 23a. With
this, the servo piston of the regulator 22 moves to a position
corresponding to the discharge volume command current, and the
swash plate 21a tilts at the tilting angle corresponding to the
position of the servo piston. Therefore, the operating oil is
discharged from the hydraulic pump 21 to the main passage 16 at the
discharge flow rate corresponding to the discharge volume command
current. The plurality of flow rate control devices 12 are
connected to the main passage 16 in parallel. In the present
embodiment, three flow rate control devices 12 are connected to the
main passage 16 in parallel.
[0045] The three flow rate control devices 12 are provided so as to
correspond to respective hydraulic actuators. The hydraulic
excavator of the present embodiment includes three cylinders, for
convenience of explanation. To be specific, the hydraulic excavator
includes a boom cylinder configured to move the boom, an arm
cylinder configured to move the arm, and a bucket cylinder
configured to move the bucket. The three flow rate control devices
12 correspond to the respective hydraulic cylinders. Each flow rate
control device 12 controls the flow direction and flow rate of the
operating oil flowing through the corresponding hydraulic cylinder.
These three flow rate control devices 12 are basically the same in
configuration as one another except that targets to which the three
flow rate control devices 12 correspond are different from one
another. Therefore, the following will just describe the
configuration of a boom flow rate control device 12 corresponding
to the boom cylinder located at the most upstream side as shown in
FIG. 1, detailed explanations of the configurations of the other
two flow rate control devices that are an arm flow rate control
device and a bucket flow rate control device are omitted since the
explanation of the configuration of the boom flow rate control
device 12 is referable.
[0046] The flow rate control device 12 includes a flow control
valve 25 and a pair of electromagnetic proportional valves 26L and
26R. The flow control valve 25 controls the flow direction and flow
rate of the operating oil supplied to the boom cylinder. More
specifically, the flow control valve 25 is connected to the main
passage 16 and also connected to the tank 15 through a tank passage
17. The flow control valve 25 is connected to the boom cylinder
through a rod-side passage 18 and a head-side passage 19. The
rod-side passage 18 is connected to a rod-side port of the boom
cylinder, and the head-side passage 19 is connected to a head-side
port of the boom cylinder. Therefore, the boom cylinder contracts
by supplying the operating oil to the rod-side passage 18 and
discharging the operating oil from the head-side passage 19. In
contrast, the boom cylinder expands by discharging the operating
oil from the rod-side passage 18 and supplying the operating oil to
the head-side passage 19.
[0047] The flow control valve 25 includes a spool 25a and changes
connection statuses of the four passages 16 to 19 in accordance
with the position of the spool 25a. To be specific, when the spool
25a is located at a neutral position M, all the four passages 16 to
19 are blocked. When the spool 25a moves to a first offset position
L, the rod-side passage 18 is connected to the main passage 16, and
the head-side passage 19 is connected to the tank passage 17. When
the spool 25a moves to a second offset position R, the rod-side
passage 18 is connected to the tank passage 17, and the head-side
passage 19 is connected to the main passage 16. Further, the
opening degrees of the four passages 16 to 19 change in accordance
with the position of the spool 25a. With this, the flow control
valve 25 can supply the operating oil to the boom cylinder at the
flow rate corresponding to the position of the spool 25a. To be
specific, the boom cylinder can be moved at a speed corresponding
to the position of the spool 25a. Pilot pressure pL and pilot
pressure pR are applied to the spool 25a so as to act against each
other, and the spool 25a having such function moves to a position
corresponding to differential pressure between the pilot pressure
pL and the pilot pressure pR. In order to apply the pilot pressure
pL and the pilot pressure pR to the spool 25a, the pair of
electromagnetic proportional valves 26L and 26R are provided at the
flow control valve 25.
[0048] The pair of electromagnetic proportional valves 26L and 26R
are direct proportion type electromagnetic proportional valves that
are similar in configuration to each other. The electromagnetic
proportional valve 26L outputs the pilot pressure pL corresponding
to an operating command current input thereto, and the
electromagnetic proportional valve 26R outputs the pilot pressure
pR corresponding to an operating command current input thereto.
More specifically, the electromagnetic proportional valves 26L and
26R are connected to the flow control valve 25, the tank 15, and
the pilot pump (not shown). Each of the electromagnetic
proportional valves 26L and 26R includes a solenoid 26a and adjusts
a connection status between the tank 15 and the flow control valve
25, a connecting status between the pilot pump and the flow control
valve 25, an opening degree between the tank 15 and the flow
control valve 25, and an opening degree between the pilot pump and
the flow control valve 25 in accordance with a current supplied to
the solenoid 26a. To be specific, the electromagnetic proportional
valve 26L has the same function as the electromagnetic proportional
valve 23 of the hydraulic pump device 11 and outputs the pilot
pressure pL corresponding to the operating command current supplied
thereto, and the electromagnetic proportional valve 26R has the
same function as the electromagnetic proportional valve 23 of the
hydraulic pump device 11 and outputs the pilot pressure pR
corresponding to the operating command current supplied thereto.
With this, the spool 25a of the flow control valve 25 moves to a
position corresponding to the operating command current, and the
operating oil is supplied to the boom cylinder in the flow
direction corresponding to the operating command current at the
flow rate corresponding to the operating command current. To be
specific, the flow control valve 25 can make the boom cylinder
expand and contract in a direction corresponding to the operating
command current at a speed corresponding to the operating command
current. In order to adjust the flow rate of the operating oil
supplied to the hydraulic cylinders including the boom cylinder,
the bleed-off valve 13 is connected to the main passage 16.
[0049] The bleed-off valve 13 is an electromagnetic proportional
valve. The bleed-off valve 13 has a function of discharging to the
tank 15 the operating oil flowing through the main passage 16,
i.e., has a function of performing bleed-off. The bleed-off valve
13 having such function includes a solenoid 13a, and a bleed-off
command current is input to the solenoid 13a. When the bleed-off
command current is input to the solenoid 13a, the bleed-off valve
13 adjusts an opening degree between the main passage 16 and the
tank 15 in accordance with the bleed-off command current. With
this, the bleed-off of the operating oil can be performed at the
flow rate corresponding to the bleed-off command current, and this
can adjust the flow rate of the operating oil flowing through the
main passage 16. In order to input the bleed-off command current to
the bleed-off valve 13 having such function, the control unit 1 is
electrically connected to the bleed-off valve 13.
[0050] Control Unit
[0051] The control unit 1 shown in FIG. 2 includes a CPU (Central
Processing Unit), a ROM (Read Only Memory), a RAM (Random Access
Memory), and the like (all not shown). The ROM stores programs
executed by the CPU, various fixed data, and the like. The programs
executed by the CPU are stored in various storage mediums, such as
flexible disks, CD-ROMs, and memory cards, and are installed to the
ROM from such storage mediums. The RAM configured as above
temporarily stores data necessary when executing the programs. The
control unit 1 is electrically connected to the solenoid 13a of the
bleed-off valve 13, the solenoid 23a of the electromagnetic
proportional valve 23 of the hydraulic pump device 11, and the
solenoids 26a of the pair of electromagnetic proportional valves
26R and 26L. In order to control the operations of the valves 13,
23, 26R, and 26L, the control unit 1 includes a control device
31.
[0052] The control device 31 is connected to an operating device
(not shown), and the operating device includes three operating
levers respectively corresponding to the boom, the arm, and the
bucket. When the operating lever is operated, the operating device
outputs to the control device 31 an operation command corresponding
to an operation direction and operation amount of the operating
lever. Then, the control device 31 supplies a command current to
the solenoid 13a, 23a, or 26a in accordance with the operation
command input thereto. With this, the corresponding hydraulic
cylinder expands or contracts in a direction corresponding to the
operation direction of the operating lever at a speed corresponding
to the operation amount of the operating lever. The control device
31 moves the hydraulic cylinders by controlling the operations of
the valves 13, 23, 26R, and 26L as above.
[0053] The control device 31 selects a normal mode or a restriction
mode as an operating mode of the hydraulic driving apparatus 2. In
the restriction mode, the function of the hydraulic driving
apparatus 2 is restricted (for example, upper limits of the pilot
pressures p, pL, and pR which can be output from the proportional
valves 23, 26R, and 26L are set low), and therefore, maximum
outputs of the hydraulic cylinders are restricted. On the other
hand, in the normal mode, the functions of the valves 23, 26R, and
26L are not restricted, and therefore, the hydraulic cylinders can
maximally exert their functions (i.e., each hydraulic cylinder can
output a maximum output set at the time of designing). These two
modes are switched in accordance with the hydraulic pump device 11
mounted on the hydraulic excavator. More specifically, when the
hydraulic pump device 11 mounted is not a proper product (i.e., a
genuine product) or is not replaced properly, the control device 31
selects the restriction mode. In order to determine whether to
switch the operating mode to the restriction mode, the control unit
1 performs individual identification of the hydraulic pump device
11 mounted on the hydraulic excavator (i.e., individual
identification of the electromagnetic proportional valve 23 of the
hydraulic pump device 11). In order to perform the individual
identification of the hydraulic pump device 11 based on the
electromagnetic proportional valve 23, the control unit 1 includes
an electromagnetic valve identification device 32.
[0054] Electromagnetic Valve Identification Device
[0055] In order to perform the individual identification of the
electromagnetic proportional valve 23, the electromagnetic valve
identification device 32 measures a resistance value and inductance
of the solenoid 23a of the electromagnetic proportional valve 23.
Regarding the resistance values of the solenoids 23a, the
resistance values of the solenoids of the electromagnetic
proportional valves of the same type vary little. On the other
hand, regarding the inductances of the solenoids 23a, the
inductance of each solenoid 23a has a specific value. However, in
many cases, even when the electromagnetic proportional valves are
of the same type (i.e., the solenoids are the same in winding
number and wire diameter as one another), the inductances of the
respective solenoids 23a of the electromagnetic proportional valves
have different numerical values due to the shapes, size variations,
and the like of magnetic bodies arranged around the electromagnetic
proportional valves. To be specific, the solenoids 23a vary.
Therefore, the individual identification of the electromagnetic
proportional valve 23 can be performed based on the resistance
value and the inductance. In order to specify the type of the
electromagnetic proportional valve and perform the individual
identification of the electromagnetic proportional valve, the
electromagnetic valve identification device 32 includes an LCR
measuring circuit 41, a calculating portion 42, a storage portion
43, a resistance measuring portion 44, and a determining portion
45. The LCR measuring circuit 41 is one example of an inductance
measuring circuit and measures the inductance of the solenoid 23a
of the electromagnetic proportional valve 23. The LCR measuring
circuit 41 is constituted by a circuit connected to the
electromagnetic proportional valve 23 by, for example, a
four-terminal method as shown in FIG. 3. A connection method and
circuit configuration adopted in the LCR measuring circuit 41 are
not limited to those shown in FIG. 3. A known circuit capable of
measuring the inductance of the solenoid 23a of the electromagnetic
proportional valve 23 may be adopted.
[0056] The LCR measuring circuit 41 and the control device 31 are
formed on a single substrate to constitute the control unit 1. It
should be noted that the LCR measuring circuit 41 does not
necessarily have to be formed on the substrate on which the control
device 31 is formed, and the LCR measuring circuit 41, the
below-described calculating portion 42, and the below-described
storage portion 43 may be configured as a different device (for
example, an LCR meter). Further, the control unit 1 including the
substrate on which the LCR measuring circuit 41 and the control
device 31 are formed includes interfaces 1a to 1d, and the
solenoids 13a, 23a, and 26a are electrically connected to the
control unit 1 by connecting harnesses 13b, 23b, and 26b to the
interfaces 1a to 1d. The interfaces 1a to 1d are connected to the
control device 31 through separate signal wires. For example, the
harness 23b of the electromagnetic proportional valve 23 of the
hydraulic pump device 11 is connected to the interface 1a, and the
control device 31 is connected to the interface 1a through signal
wires 1e and 1f. The LCR measuring circuit 41 is connected to the
signal wires 1e and 1f through below-described four terminals Hc,
Hp, Lp, and Lc. Hereinafter, the configuration of the LCR measuring
circuit 41 will be described in more detail.
[0057] The LCR measuring circuit 41 includes an oscillator 51, a
current-voltage converter 52, and a vector voltmeter 53. The
oscillator 51 generates an alternating current of a predetermined
frequency (for example, 100 Hz) in accordance with a command from
the control device 31 and includes an internal resistance Rs. The
oscillator 51 includes a first terminal Hc, and the first terminal
Hc is connected to the first signal wire 1e. On the other hand, a
second terminal Lc of the current-voltage converter 52 is connected
to the second signal wire 1f. The current-voltage converter 52
includes a reference resistance 52a and a control amplifier 52b.
While suppressing an influence of a stray capacitance 54, the
current-voltage converter 52 converts the alternating current,
flowing through the solenoid 23a of the electromagnetic
proportional valve 23, into a voltage such that the voltage is
detectable. To be specific, a voltage difference corresponding to
the alternating current flowing through the solenoid 23a of the
electromagnetic proportional valve 23 is generated across the
reference resistance 52a, and the voltage applied to the reference
resistance 52a is measured by the vector voltmeter 53.
[0058] More specifically, the vector voltmeter 53 includes two
voltmeters 53a and 53b. The first voltmeter 53a is connected to the
first signal wire 1e through a third terminal Hp and connected to
the second signal wire if through a fourth terminal Lp. With this,
the first voltmeter 53a measures a voltage V1 applied to the
solenoid 23a of the electromagnetic proportional valve 23. The
second voltmeter 53b is connected to portions in front of and
behind the reference resistance 52a and measures a voltage V2
applied to the reference resistance 52a. The inductance of the
solenoid 23a can be measured based on the two voltages V1 and V2
measured as above, and the measured voltages V1 and V2 and the
alternating current output from the oscillator 51 are output to the
calculating portion 42.
[0059] The calculating portion 42 refers to the alternating current
output from the oscillator 51 and calculates the inductance of the
solenoid 23a based on the two voltages V1 and V2 measured by the
vector voltmeter 53. The calculated inductance is stored in the
storage portion 43 shown in FIG. 2. In addition to the inductance,
the storage portion 43 stores the resistance value of the solenoid
23a. In order to measure the resistance value, the electromagnetic
valve identification device 32 includes the resistance measuring
portion 44. The resistance measuring portion 44 measures the
resistance value of the solenoid 23a. To be specific, when a
predetermined direct current is supplied from the control device 31
to the solenoid 23a, the resistance measuring portion 44 measures
the voltage applied to the solenoid 23a and calculates the
resistance value of the solenoid 23a based on this voltage and the
supplied direct current. The storage portion 43 stores the
calculated resistance value together with the inductance. With
this, the resistance value and the inductance can be stored in the
storage portion 43 as individual identification information of the
electromagnetic proportional valve 23 of the hydraulic pump device
11, i.e., individual identification information of the hydraulic
pump device 11. Further, each of the stored inductance and the
stored resistance value is stored as a reference value or an
actually measured value in accordance with the mode selected when
below-described calculations are performed. The reference value and
the actually measured value stored as above are used in the
determining portion 45 as below.
[0060] The determining portion 45 mainly determines whether or not
the electromagnetic proportional valve 23 has been replaced, i.e.,
whether or not the hydraulic pump device 11 has been replaced. To
be specific, the determining portion 45 performs two determinations
that are a genuine product determination and a replacement
determination. In the genuine product determination, whether or not
the electromagnetic proportional valve 23 has been replaced, i.e.,
whether or not the hydraulic pump device 11 has been replaced is
determined based on the following determination criterion. To be
specific, the determination criterion is whether or not the
actually measured resistance value stored as the actually measured
value is a numerical value that falls within a predetermined
allowable range (i.e., a resistance value allowable range) and
whether or not the actually measured inductance stored as the
actually measured value is a numerical value that falls within a
predetermined allowable range (i.e., an inductance allowable
range). For example, in the case of the electromagnetic
proportional valves 23 that are the genuine products, the solenoids
23a are manufactured within a predetermined manufacturing error
(tolerance). Therefore, the measured numerical values of the
resistance values and inductances do not exceed the manufacturing
error with exceptions, such as breakdown. Therefore, when the
actually measured resistance value falls outside the allowable
range set in accordance with the manufacturing error, and the
actually measured inductance falls outside the allowable range set
in accordance with the manufacturing error, the determining portion
45 determines that the hydraulic pump device 11 is not the genuine
product. On the other hand, when the actually measured resistance
value falls within the allowable range, and the actually measured
inductance falls within the allowable range, the determining
portion 45 determines that the hydraulic pump device 11 is the
genuine product.
[0061] On the other hand, in the replacement determination, the
reference value and the actually measured measurement value are
compared with each other, and based on the determination criterion
that is whether or not the reference value and the actually
measured measurement value are different from each other, whether
or not the electromagnetic proportional valve 23 has been replaced
is determined, i.e., whether or not the hydraulic pump device 11
has been replaced is determined. To be specific, the type of the
electromagnetic proportional valve 23 can be specified by the
resistance value of the solenoid 23a of the electromagnetic
proportional valve 23, and the individual identity of the
electromagnetic proportional valve 23 can be determined by the
inductance of the solenoid 23a of the electromagnetic proportional
valve 23. With this, whether or not the same electromagnetic
proportional valve 23 is being continuously mounted can be
determined by comparison between the actually measured measurement
value and the reference value, and based on the result of this
determination, whether or not the electromagnetic proportional
valve 23 has been replaced, i.e., whether or not the hydraulic pump
device 11 has been replaced can be determined. As above, the
determining portion 45 performs the genuine product determination
and the replacement determination to determine whether or not the
hydraulic pump device 11 is the genuine product and whether or not
the hydraulic pump device 11 has not been replaced. When the
hydraulic pump device 11 is an improper product, or when the
hydraulic pump device 11 has been replaced, the control device 31
restricts the movements of the hydraulic cylinders.
[0062] As above, the control unit 1 performs the genuine product
determination and the replacement determination based on the
reference values and the allowable ranges. As described above, the
control unit 1 stores the reference values (a reference resistance
value and a reference inductance) and the actually measured
measurement values (the actually measured resistance value and the
actually measured inductance) in accordance with the
below-described mode. In order to select such mode, a measurement
mode selector 46 is electrically connected to the control unit 1.
The measurement mode selector 46 is constituted by, for example, an
operation panel and can select a reference value measurement mode
or an actually measured value measurement mode. The reference value
measurement mode is a mode in which the reference resistance value
and the reference inductance are measured in order to store the
reference resistance value and the reference inductance in the
storage portion 43. To be specific, in the reference value
measurement mode, the measured resistance value and inductance are
stored in the storage portion 43 as the individual identification
information of the hydraulic pump device 11 to be used. In the
control unit 1, the hydraulic pump device 11 to be used is
registered by storing the reference values. In the present
embodiment, selection of the reference value measurement mode
corresponds to satisfaction of a reference value setting condition.
On the other hand, the actually measured value measurement mode is
a mode in which: the actually measured resistance value and the
actually measured inductance are measured; and the genuine product
determination and the replacement determination are executed based
on the actually measured resistance value and the actually measured
inductance, and is a mode in which the individual identification of
the hydraulic pump device 11 is performed.
[0063] As above, the measurement mode selector 46 can select any
one of these two modes. When one of the two modes is selected, the
measurement mode selector 46 gives a command to the control device
31 such that processing corresponding to the selected mode is
performed. It should be noted that it is preferable that in order
to prevent the registered hydraulic pump device 11 from being
changed unreasonably, the reference value measurement mode be not
selectable without inputting a preset password or the like. To be
specific, it is preferable that at places other than manufacturing
factories and certified factories, the reference value measurement
mode be not selectable, and the actually measured value measurement
mode be selected at all times. With this, it is possible to prevent
a case where the reference values are changed, and the
electromagnetic proportional valve 23 is made to look as if it has
not been replaced. Thus, it is possible to prevent a case where the
hydraulic pump device 11 is replaced by an improper method at
places other than the manufacturing factories and the certified
factories. As above, the control unit 1 registers the hydraulic
pump device 11 to be used or performs the individual identification
of the hydraulic pump device 11 to be used, in accordance with the
selection of the mode by the measurement mode selector 46.
Hereinafter, the procedure of the individual identification
processing of the control unit 1 will be described with reference
to the flow charts of FIGS. 4 to 6.
[0064] Individual Identification Processing
[0065] When a main switch of the hydraulic excavator is turned on,
and the control unit 1 is supplied with electric power, the
individual identification processing by the control unit 1 starts,
and the process proceeds to Step 51 as shown in FIG. 4. In Step S1
that is a measurement mode determining step, whether or not the
mode selected by the measurement mode selector 46 is the reference
value measurement mode is determined. When it is determined that
the mode selected is the reference value measurement mode, the
process proceeds to Step S2. In Step S2 that is a reference value
measuring step, reference value measurement processing shown in
FIG. 5 is executed. The reference value measurement processing is
processing in which the reference resistance value and reference
inductance of the solenoid 23a are measured and stored in the
storage portion 43. When the reference value measurement processing
is executed, the process proceeds to Step S11.
[0066] In Step S11 that is a reference resistance value measuring
step, the reference resistance value of the solenoid 23a of the
electromagnetic proportional valve 23 of the hydraulic pump device
11 is measured. To be specific, the control device 31 supplies a
predetermined direct current to the solenoid 23a of the
electromagnetic proportional valve 23 and makes the resistance
measuring portion 44 measure the voltage applied to the solenoid
23a and calculate the reference resistance value of the solenoid
23a. After the reference resistance value is calculated, the
process proceeds to Step S12. In Step S12 that is a reference
inductance measuring step, the reference inductance of the solenoid
23a of the electromagnetic proportional valve 23 of the hydraulic
pump device 11 is measured. To be specific, the control device 31
makes the oscillator 51 of the LCR measuring circuit 41 output the
alternating current and makes the vector voltmeter 53 measure the
voltages V1 and V2. Further, the control device 31 makes the
calculating portion 42 calculate the reference inductance of the
solenoid 23a based on the measured voltages V1 and V2. After the
reference inductance is calculated, the process proceeds to Step
S13.
[0067] In Step S13 that is a reference value storing step, the
reference resistance value measured in Step S11 and the reference
inductance measured in Step S12 are stored in the storage portion
43. The reference resistance value and the reference inductance
stored as above are stored in the storage portion 43 as the
individual identification information of the hydraulic pump device
11, and with this, an electrical characteristic of the hydraulic
pump device 11 mounted is registered in the control unit 1. Then,
the process proceeds to Step S14. In Step S14 that is a mode
terminating step, the control device 31 terminates the reference
value measurement mode. With this, the reference value measurement
processing is terminated, and the process returns to Step S1 from
Step S2. Further, when it is determined in Step S1 that the mode
selected is the actually measured value measurement mode, the
process proceeds to Step S3.
[0068] In Step S3 that is a measurement standby step, whether or
not a predetermined time has elapsed since the measurement of the
resistance value and inductance is determined. To be specific, the
control device 31 measures an elapsed time since the termination of
the above-described reference value measurement processing or the
termination of the below-described actually measured value
measurement processing and determines whether or not the elapsed
time is a predetermined time or more. When the elapsed time is less
than the predetermined time, the process returns to Step S1. When
the elapsed time is the predetermined time or more, the process
proceeds to Step S4. In Step S4 that is an actually measured value
measuring step, the actually measured value measurement processing
shown in FIG. 6 is executed. The actually measured value
measurement processing is processing in which the resistance value
(i.e., the actually measured resistance value) and inductance
(i.e., the actually measured inductance) of the solenoid 23a are
measured as the actually measured measurement values to be compared
with the reference values. When the actually measured value
measurement processing is executed, the process proceeds to Step
S21.
[0069] In Step S21 that is an actually measured resistance value
measuring step, the actually measured resistance value of the
solenoid 23a of the electromagnetic proportional valve 23 of the
hydraulic pump device 11 is measured. To be specific, the control
device 31 supplies a predetermined direct current to the solenoid
23a of the electromagnetic proportional valve 23 and makes the
resistance measuring portion 44 measure the voltage applied to the
solenoid 23a and calculate the actually measured resistance value
of the solenoid 23a. After the actually measured resistance value
is calculated, the process proceeds to Step S22. In Step S22 that
is an actually measured inductance measuring step, the actually
measured inductance of the solenoid 23a of the electromagnetic
proportional valve 23 of the hydraulic pump device 11 is measured.
To be specific, the control device 31 makes the oscillator 51 of
the LCR measuring circuit 41 output the alternating current and
makes the vector voltmeter 53 measure the voltages V1 and V2.
Further, the control device 31 makes the calculating portion 42
calculate the actually measured inductance of the solenoid 23a
based on the measured voltages V1 and V2. After the actually
measured inductance is calculated, the process proceeds to Step
S23.
[0070] In Step S23 that is an actually measured measurement value
storing step, the actually measured resistance value measured in
Step S21 and the actually measured inductance measured in Step S22
are stored in the storage portion 43. To be specific, the actually
measured resistance value and the actually measured inductance are
stored in the storage portion 43 as the individual identification
information of the hydraulic pump device 11 mounted currently.
Then, the process proceeds to Step S24.
[0071] In Step S24 that is a genuine product determining step,
based on the actually measured measurement values stored in Step
S23, the determining portion 45 executes the genuine product
determination to determine whether or not the hydraulic pump device
11 mounted currently is the genuine product. To be specific, the
determining portion 45 determines whether or not the actually
measured resistance value is a numerical value that falls within
the predetermined resistance value allowable range and also
determines whether or not the actually measured inductance is a
numerical value that falls within the predetermined inductance
allowable range. When it is determined that both the actually
measured resistance value and the actually measured inductance are
the respective numerical values that fall within the respective
allowable ranges, the process proceeds to Step S25.
[0072] In Step S25 that is a replacement determining step, based on
the reference values stored in the reference value measurement
processing and the actually measured measurement values stored in
Step S24, the determining portion 45 executes the replacement
determination to determine whether or not the hydraulic pump device
11 mounted currently is a hydraulic pump device that has been
mounted after the execution of the reference value measurement
processing. To be specific, the determining portion 45 compares the
reference resistance value with the actually measured resistance
value and determines whether or not the reference resistance value
and the actually measured resistance value are different from each
other (i.e., whether or not the reference resistance value and the
actually measured resistance value coincide with each other).
Further, the determining portion 45 compares the reference
inductance with the actually measured inductance and determines
whether or not the reference inductance and the actually measured
inductance are different from each other (i.e., whether or not the
reference inductance and the actually measured inductance coincide
with each other). It should be noted that a case where the
reference value and the actually measured value coincide with each
other denotes not only a case where the reference value and the
actually measured value completely coincide with each other but
also a case where the actually measured value falls within a
predetermined range with respect to the reference value. To be
specific, when a difference between the reference value and the
actually measured value falls within a predetermined threshold, it
is determined that the reference value and the actually measured
value coincide with each other (the reference value and the
actually measured value are not different from each other). As
above, when it is determined that the actually measured resistance
value and the actually measured inductance are not different from
the respective reference values, i.e., coincide with the respective
reference values, the process proceeds to Step S26.
[0073] In Step S26 that is a normal mode setting step, the
operating mode of the hydraulic driving apparatus 2 is set to (or
maintained in) the normal mode. With this, the control device 31
allows the hydraulic driving apparatus 2 to maximally exert the
function. After the operating mode is set the normal mode as above,
the actually measured value measurement processing terminates. On
the other hand, when the determining portion 45 determines in Step
S24 of the actually measured value measurement processing that the
actually measured resistance value or the actually measured
inductance does not fall within the corresponding allowable range,
or when the determining portion 45 determines by comparison in Step
S25 that the reference inductance and the actually measured
inductance are different from each other, the process proceeds to
Step S27.
[0074] In Step S27 that is a restriction mode setting step, the
operating mode of the hydraulic driving apparatus 2 is set to (or
maintained in) the restriction mode. With this, the function of the
hydraulic driving apparatus 2 is restricted, and the maximum
outputs that can be output by the respective hydraulic cylinders
are restricted. To be specific, when the hydraulic pump device 11
that is a non-genuine product is mounted, or when the hydraulic
pump device 11 is replaced through a procedure that is not the
proper procedure, the hydraulic pump device 11 can be operated only
at a low-level output. Therefore, it is possible to prevent a case
where when the performance of the hydraulic driving apparatus 2 is
made low since the hydraulic pump device 11 that is a non-genuine
product is mounted or when the hydraulic pump device 11 is replaced
through a procedure that is not the proper procedure, the hydraulic
driving apparatus 2 is made to perform overwork that is more than
the performance, and as a result, the hydraulic driving apparatus 2
breaks, for example. After the operating mode is set to the
restriction mode as above, the actually measured value measurement
processing terminates. It should be noted that the restriction mode
continues until the process proceeds to Step S26, and the operating
mode is set to the normal mode. To be specific, the function of the
hydraulic driving apparatus 2 is restricted as long as it is
determined in Step S24 that the actually measured resistance value
or the actually measured inductance is a numerical value that falls
outside the corresponding allowable range, or it is determined by
comparison in Step S25 that the reference inductance and the
actually measured inductance are different from each other. On the
other hand, by replacing the hydraulic pump device 11 with the
genuine product at a certified factory or the like and resetting
the reference values in the reference value measurement processing,
the restriction mode can be canceled, and the operating mode can be
reset to the normal mode.
[0075] As above, when the operating mode of the hydraulic driving
apparatus 2 is set to the normal mode or the restriction mode, the
actually measured value measurement processing is terminated. After
the actually measured value measurement processing is terminated,
the process returns to Step S1 from Step S4, and the determination
of the measurement mode is performed again. Therefore, in the
individual identification processing, the actually measured value
measurement processing is repeatedly performed for every
predetermined time until the reference value measurement mode is
selected. The individual identification processing is terminated by
turning off the main switch of the hydraulic excavator.
[0076] As above, by mounting the electromagnetic valve
identification device 32 on the industrial vehicle, the individual
identification of the electromagnetic proportional valve 23 and the
individual identification of the hydraulic pump device 11 including
the electromagnetic proportional valve 23 can be performed.
Therefore, it is unnecessary to attach IC chips to the
electromagnetic proportional valves 23 and the hydraulic pump
devices 11 mounted on the industrial vehicles or attach IDs to the
electromagnetic proportional valves 23 and the hydraulic pump
devices 11 mounted on the industrial vehicles to manage the
electromagnetic proportional valves 23 and the hydraulic pump
devices 11, in order to perform the individual identification of
the electromagnetic proportional valves 23. Thus, the manufacturing
cost can be suppressed. Further, since not only the inductance of
the solenoid 23a but also the resistance value of the solenoid 23a
are used, the individual identification of the electromagnetic
proportional valve 23 and the individual identification of the
hydraulic pump device 11 including the electromagnetic proportional
valve 23 can be performed more accurately than when only the
inductance is used.
[0077] Further, by comparing the measured inductance with the
reference inductance, the control unit 1 can determine whether or
not the electromagnetic proportional valve 23 has been replaced.
Therefore, whether or not the hydraulic pump device 11 has been
replaced can be determined by a simple configuration without
attaching IC chips to the hydraulic pump devices 11 or attaching
IDs to the hydraulic pump devices 11 to manage the hydraulic pump
devices 11. Especially, whether or not the same electromagnetic
proportional valve 23 is being continuously mounted can be
determined based on whether or not the reference inductance and the
actually measured inductance are different from each other. When it
is determined that the same electromagnetic proportional valve 23
is not being continuously mounted, it can be determined that the
electromagnetic proportional valve 23 has been replaced at a
certain time point. Therefore, whether or not the replacement work
has been performed can be surely determined. On this account,
whether or not the replacement work has been performed can be
determined, and the function of the hydraulic driving apparatus 2
can be restricted when the replacement has been performed through a
procedure that is not the proper procedure.
[0078] When the electromagnetic proportional valve 23 has been
replaced, the control unit 1 can execute the reference value
measurement processing to reset the reference inductance and the
reference resistance value (i.e., the reference values). On the
other hand, when the electromagnetic proportional valve 23 has been
replaced in a state where the reference value measurement
processing cannot be executed, the reference values cannot be
changed, and the function of the hydraulic driving apparatus 2 is
restricted continuously. Therefore, by realizing the reference
value measurement processing by which the replacement can be
performed through the proper procedure at the certified factory or
the like, the hydraulic driving apparatus 2 can be made to
maximally exert the function only when the electromagnetic
proportional valve 23 is replaced through the proper procedure.
Further, since the reference values cannot be reset without
executing the reference value measurement processing, it is
possible to prevent a case where the reference values are changed,
and the electromagnetic proportional valve 23 is made to look as if
it has not been replaced.
Embodiment 2
[0079] The control unit 1A of Embodiment 2 is similar in
configuration to the control unit 1 of Embodiment 1. Therefore,
components of the control unit 1A of Embodiment 2 which are
different from the components of the control unit 1 of Embodiment 1
will be mainly described. The same reference signs are used for the
same components, and explanations thereof are omitted.
[0080] As shown in FIG. 7, the control unit 1A of Embodiment 2
includes an electromagnetic valve identification device 32A and the
control device 31, and the electromagnetic valve identification
device 32A includes the storage portion 43, the resistance
measuring portion 44, and a determining portion 45A. To be
specific, in order to measure the resistance value of the solenoid
23a, the control unit 1A supplies a predetermined direct current
from the control device 31 to the solenoid 23a. At this time, the
resistance measuring portion 44 measures the voltage applied to the
solenoid 23a and calculates the resistance value of the solenoid
23a based on this voltage and the supplied direct current. The
storage portion 43 stores the calculated resistance value as the
individual identification information of the electromagnetic
proportional valve 23 of the hydraulic pump device 11, i.e., the
individual identification information of the hydraulic pump device
11. The stored resistance value is stored as the reference
resistance value or the actually measured resistance value in
accordance with the selected mode. The reference resistance value
and the actually measured resistance value stored as above are used
when determining whether or not the electromagnetic proportional
valve 23 has been replaced, i.e., whether or not the hydraulic pump
device 11 has been replaced.
[0081] To be specific, the type of the electromagnetic proportional
valve 23 can be specified by the resistance value of the solenoid
23a, and whether or not the same electromagnetic proportional valve
23 is being continuously mounted can be determined by comparison
between the stored reference resistance value and the stored
actually measured resistance value. Therefore, based on the result
of this determination, whether or not the electromagnetic
proportional valve 23 has been replaced, i.e., whether or not the
hydraulic pump device 11 has been replaced can be determined. On
this account, the determining portion 45A determines whether or not
the electromagnetic proportional valve 23 has been replaced, i.e.,
whether or not the hydraulic pump device 11 has been replaced,
based on the determination criterion that is whether or not the
stored reference resistance value and the stored actually measured
resistance value are different from each other. As above, the
determining portion 45A determines by the replacement determination
whether or not the hydraulic pump device 11 has been replaced. When
the improper product is used, or when the hydraulic pump device 11
has been replaced, the control device 31 restricts the movements of
the hydraulic cylinders.
[0082] As above, in order to select the reference value measurement
mode or the actually measured value measurement mode, the control
unit 1A is electrically connected to the measurement mode selector
46 and can select the mode by the measurement mode selector 46. In
the reference value measurement mode, the resistance value measured
by the resistance measuring portion 44 is stored in the storage
portion 43 as the reference resistance value, i.e., the measured
resistance value is stored in the storage portion 43 as the
individual identification information of the hydraulic pump device
11. On the other hand, in the actually measured value measurement
mode, the above-described replacement determination is performed
based on the actually measured resistance value and the prestored
reference resistance value. As with the control unit 1 of
Embodiment 1, it is preferable that: the reference value
measurement mode be not selectable at places other than the
manufacturing factories, the certified factories, and the like; and
the actually measured value measurement mode be selected at all
times.
[0083] As above, the control unit 1A registers the hydraulic pump
device 11 to be used or performs the individual identification of
the hydraulic pump device 11 to be used in accordance with the mode
selection performed by the measurement mode selector 46. It should
be noted that the procedure of the individual identification
processing of the control unit 1A is similar to the procedure of
the individual identification processing of the control unit 1 of
Embodiment 1, and the following will mainly describe
differences.
[0084] According to the individual identification processing
performed by the control unit 1A, when the reference resistance
value of the solenoid 23a is measured in Step S11 of the reference
value measurement processing, the process proceeds to Step S13, and
the measured reference resistance value is stored in the storage
portion 43 as the individual identification information of the
hydraulic pump device 11. Further, when the actually measured
resistance value of the solenoid 23a of the electromagnetic
proportional valve 23 is measured in Step S21 of the actually
measured value measurement processing, the process proceeds to Step
S23, and the obtained actually measured resistance value is stored
in the storage portion 43 as the individual identification
information of the hydraulic pump device 11. After the actually
measured resistance value is stored, it is confirmed in Step 24
that the actually measured resistance value falls within an
allowable value. After it is confirmed that the actually measured
resistance value falls within the allowable value, the process
proceeds to Step S25. The reference resistance value stored in the
reference value measurement processing and the actually measured
resistance value stored in Step S24 are compared with each other,
and whether or not the hydraulic pump device 11 mounted currently
is a hydraulic pump device that has been mounted after the
execution of the reference value measurement processing is
determined. When the hydraulic pump device 11 has not been
replaced, the process proceeds to Step S26, and the normal mode is
set. When the hydraulic pump device 11 has been replaced, the
process proceeds to Step S27, and the operating mode of the
hydraulic driving apparatus 2 is set to (or maintained in) the
restriction mode.
[0085] As above, the control unit 1A can determine based on the
measured resistance values whether or not the electromagnetic
proportional valve 23 has been replaced. More specifically, whether
or not the same electromagnetic proportional valve 23 is being
continuously mounted can be determined by comparison between the
reference resistance value and the actually measured resistance
value. Therefore, whether or not the hydraulic pump device 11 has
been replaced can be determined by a simple configuration without
attaching IC chips to the hydraulic pump devices 11 or attaching
IDs to the hydraulic pump devices 11 to manage the hydraulic pump
devices 11.
[0086] Other than the above, the control unit 1A of Embodiment 2
can obtain the same operational advantages as the control unit 1 of
Embodiment 1.
[0087] Other Embodiment
[0088] Each of the control units 1 and 1A of Embodiments 1 and 2
regards the electromagnetic proportional valve 23 of the hydraulic
pump device 11 as an identification target. However, the
identification target is not necessarily limited to this. The
identification target may be, for example, the flow rate control
device 12 or the bleed-off valve 13. In the case of the flow rate
control device 12, at least one of the resistance values and
inductances of the solenoids 26a of the electromagnetic
proportional valves 26L and 26R of the flow rate control device 12
is measured, and the individual identification of the flow rate
control device 12 is performed. In the case of the bleed-off valve
13, at least one of the resistance value and inductance of the
solenoid 13a of the bleed-off valve 13 is measured, and the
individual identification of the bleed-off valve 13 may be
performed. Further, the individual identification executed by the
control units 1 and 1A is not limited to the individual
identification of one electromagnetic proportional valve 23 and may
be the individual identification of a plurality of electromagnetic
proportional valves 13, 23, 26L, and 26R. In this case, the LCR
measuring circuit 41 and the resistance measuring portion 44 are
connected to the electromagnetic proportional valves 13, 23, 26L,
and 26R through a switching device and measure the inductance and
the resistance value while switching the measurement targets by the
switching device.
[0089] According to the control units 1 and 1A of Embodiments 1 and
2, the target for the individual identification is the
electromagnetic proportional valve. However, the target for the
individual identification is not limited to the electromagnetic
proportional valve and is only required to be an electromagnetic
type valve including a solenoid, i.e., an electromagnetic valve.
Further, the control unit 1 measures both the inductance and
resistance value of the solenoid 23a but does not necessarily have
to measure both the inductance and resistance value of the solenoid
23a. To be specific, as with the control unit 1A, only the
resistance of the solenoid 23a may be measured and stored as the
individual identification information, or only the inductance of
the solenoid 23a may be measured and stored as the individual
identification information. Further, based on such individual
identification information, whether or not the electromagnetic
proportional valve 23 has been replaced may be determined.
[0090] The determining portion 45 of the control unit 1 executes
both the genuine product determination and the replacement
determination but does not necessarily have to execute both the
genuine product determination and the replacement determination. To
be specific, the determining portion 45 may execute only one of the
genuine product determination and the replacement determination.
Further, the control unit 1 may just store the individual
identification information of the electromagnetic proportional
valve 23 in the storage portion 43 without executing the genuine
product determination and the replacement determination. With this,
when the hydraulic driving apparatus 2 breaks, whether or not the
genuine product has been used and whether or not the replacement
has been properly performed can be determined based on the
individual identification information. Further, the replacement
determination is performed based on the reference inductance
measured and stored in the reference value measurement processing,
but the reference inductance is not limited to such value. One
example may be such that: the actually measured inductance measured
in the previously-performed actually measured value measurement
processing is set as the reference inductance; and the actually
measured inductance measured in the previously-performed actually
measured value measurement processing is compared with the actually
measured inductance measured in the most-recently-performed
actually measured value measurement processing.
[0091] Further, the LCR measuring circuit does not have to be
configured by the four-terminal method and may be configured by,
for example, a two-terminal method. Further, the control unit 1
restricts the hydraulic driving apparatus 2 in the same manner
between when it is determined in the genuine product determination
that the hydraulic pump device 11 is not the genuine product and
when it is determined in the replacement determination that the
hydraulic pump device 11 has been replaced improperly. However, the
control unit 1 does not necessarily have to operate as above. For
example, when the electromagnetic valve that is not the genuine
product, the control unit 1 may restrict the maximum output (a
maximum speed or a maximum propulsive force) of the hydraulic
cylinder more strongly than when the electromagnetic valve is the
genuine product but has been replaced improperly. With this, the
replacement using the genuine product can be promoted.
[0092] Further, the control units 1 and 1A of Embodiments 1 and 2
are applied to travelable construction machines and industrial
vehicle. However, Embodiments 1 and 2 are not limited to these. For
example, the control units 1 and 1A of Embodiments 1 and 2 may be
applied to fixed industrial machines.
REFERENCE SIGNS LIST
[0093] 1, 1A control unit
[0094] 2 hydraulic driving apparatus
[0095] 11 hydraulic pump device
[0096] 13 bleed-off valve (electromagnetic valve)
[0097] 13a solenoid
[0098] 23 electromagnetic proportional valve (electromagnetic
valve)
[0099] 23a solenoid
[0100] 26L, 26R electromagnetic proportional valve (electromagnetic
valve)
[0101] 26a solenoid
[0102] 31 control device
[0103] 32, 32A electromagnetic valve identification device
[0104] 41 LCR measuring circuit (inductance measuring circuit)
[0105] 42 calculating portion
[0106] 43 storage portion
[0107] 44 resistance measuring portion
[0108] 45, 45A determining portion (replacement determining
portion)
[0109] 46 measurement mode selector
* * * * *