U.S. patent application number 11/447108 was filed with the patent office on 2007-02-01 for electric mirror control device.
This patent application is currently assigned to MURAKAMI CORPORATION. Invention is credited to Hiromi Iwasaki, Ayako Yamada.
Application Number | 20070024996 11/447108 |
Document ID | / |
Family ID | 37022988 |
Filed Date | 2007-02-01 |
United States Patent
Application |
20070024996 |
Kind Code |
A1 |
Iwasaki; Hiromi ; et
al. |
February 1, 2007 |
Electric mirror control device
Abstract
An electric mirror control device is provided which can prevent
generation of a clutch noise by stopping slipping of a clutch
provided at an actuator as quickly as possible while preventing
narrowing of an allowable range of a tilting angle of a mirror
surface. In controlling an electric mirror, a control device clamps
a voltage value of a voltage applied to a motor detected by a
mirror surface angle detection circuit to a predetermined upper
limit value and a predetermined lower limit value at a clamp
circuit. Stop control of the motor is performed based on the
voltage value clamped to the upper limit value and the lower limit
value in this way.
Inventors: |
Iwasaki; Hiromi;
(Fujieda-shi, JP) ; Yamada; Ayako; (Fujieda-shi,
JP) |
Correspondence
Address: |
C. IRVIN MCCLELLAND;OBLON, SPIVAK, MCCLELLAND, MAIER & NEUSTADT, P.C.
1940 DUKE STREET
ALEXANDRIA
VA
22314
US
|
Assignee: |
MURAKAMI CORPORATION
Shizuoka-shi
JP
|
Family ID: |
37022988 |
Appl. No.: |
11/447108 |
Filed: |
June 6, 2006 |
Current U.S.
Class: |
359/841 |
Current CPC
Class: |
B60R 1/07 20130101; Y10S
359/90 20130101; B60R 1/074 20130101; B60R 1/072 20130101 |
Class at
Publication: |
359/841 |
International
Class: |
G02B 5/08 20060101
G02B005/08; G02B 7/18 20060101 G02B007/18 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 1, 2005 |
JP |
2005-223331 |
Claims
1. An electric mirror control device, including a control method
for an automobile electric mirror in which drive control of the
electric mirror is performed by controlling an actuator for
operating the electric mirror mounted on an automobile, comprising:
a voltage sensor for detecting a voltage value applied to the
actuator when the actuator is in operation; a clamp means for
clamping the voltage value detected by the voltage sensor to a
predetermined limit value; and a stop control means for performing
stop control of the actuator based on the voltage value detected by
the voltage sensor and outputted through the clamp means.
2. The electric mirror control device according to claim 1, wherein
at least one of a predetermined upper limit value and a
predetermined lower limit value is set as the limit value, and
wherein the stop control means stops the actuator when the voltage
value detected by the voltage sensor exceeds the predetermined
upper limit value or drops below the predetermined lower limit
value.
3. The electric mirror control device according to claim 1, wherein
the electric mirror has a case to which a mirror main body is
mounted, a mirror surface angle of the mirror main body being
adjustable with respect to the case, and the actuator drives the
mirror main body so that the mirror surface angle of the mirror
main body is adjusted.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The disclosure of Japanese Patent Application No.
JP2005-223331 filed on Aug. 01, 2005 including the specification,
drawings and abstract is incorporated herein by reference in its
entirety.
BACKGROUND OF THE INTENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to an electric mirror control
device and particularly to an electric mirror control device in
which mirror surface adjustment and electric storage are carried
out in an automobile electric mirror.
[0004] 2. Related Background Art
[0005] As an automobile electric mirror to be mounted on an
automobile, there is a type providing a mirror main body and a case
for containing this mirror main body. In this type of electric
mirror, the mirror main body often includes such an arrangement
that a mirror surface angle is adjustable with respect to the case,
and some electric mirrors are equipped with an actuator for
adjusting the mirror surface angle. This type of electric mirror is
arranged so that the mirror surface angle can be adjusted by
driving the actuator.
[0006] In this type of electric mirror, a moving range of the
mirror main body with respect to the case has an allowable range.
If the mirror main body attempts to move beyond this allowable
range, a clutch provided between the actuator and the mirror main
body slips. Thus, by slipping of the clutch, the mirror main body
is prevented from moving to a position beyond the allowable range.
However, in case that the clutch is slipping, clutch noise is
generated, which might give unpleasantness to a driver. Therefore,
there is a problem that such a clutch noise should be eliminated or
finished as soon as possible even if it is generated.
[0007] Also, in some automobile electric mirrors, use state and
fold state are defined and when the electric mirror is opened with
respect to a vehicle, the mirror is defined to be in use state and
when closed, to be in fold state. Further, in such electric
mirrors, an actuator for rotationally driving the case is provided,
and positions can be switched between the use state and fold state
by driving the actuator. In this type of the automobile electric
mirror, the above problem of the clutch noise is also
generated.
[0008] In order to cope with these problems, conventionally there
is an electric mirror control device disclosed in Japanese Patent
Application Laid-Open No. 2003-200783. This electric mirror control
device is provided with a tilting means to tilt a mirror surface,
and a control means to control tilting and stop tilting of the
mirror surface by this tilting means. The control means is arranged
so that an angle detecting means determines that a detected angle
limit is reached when a detected angle value of the mirror surface
becomes constant while the mirror surface is tilted by the tilting
means.
[0009] However, with the electric mirror control device disclosed
in the above Patent Document 1, it is determined that the detected
angle limit is reached when a detected angle value of the mirror
surface becomes constant. Here, if the detected angle value to
determine that the detected angle limit is reached is set low, the
determination is made that the detected angel limit is reached
before reaching an allowable range, and as a result, there is a
fear that the allowable range of a tilting angle of the mirror
surface might be narrowed. On the other hand, if the detected angle
value is set high, though the allowable range of the tilting angle
is widened, excessive tilting beyond the allowable range is
promoted, which brings about a problem of more frequent clutch
slipping.
[0010] Thus, an object of the present invention is to provide an
electric mirror control device which can stop slipping of a clutch
disposed in an actuator as quickly as possible while preventing the
allowable range of a tilting angle of a mirror surface from being
narrowed, and can prevent generation of clutch noise.
SUMMARY OF THE INVENTION
[0011] An electric mirror control device for an automobile
according to the present invention which solved the above problems
includes a control method for an automobile electric mirror in
which drive control of the electric mirror is performed by
controlling an actuator for operating the electric mirror mounted
on an automobile, comprising: a voltage sensor for detecting a
voltage value applied to the actuator when the actuator is
operated; a clamp means for clamping the voltage value detected by
the voltage sensor at a predetermined limit value; and a stop
control means for performing stop control of the actuator based on
the voltage value detected by the voltage sensor and outputted
through the clamp means.
[0012] In the case that an operation limit (allowable range) of an
electric mirror is arranged to be detected based on a voltage value
detected by a voltage sensor, the operation limit deviation is
induced with high possibility due to fluctuation of the voltage in
the vicinity of the operation limit. The problem of operation limit
deviation can be avoided by setting the limit value high, but in
this case, stop of the actuator is delayed, which promotes clutch
slipping. In this respect, in the electric mirror control device
according to the present invention, a clamp means is provided for
clamping a voltage value detected by the voltage sensor to a
predetermined limit value, and stop control of the actuator is
performed based on the voltage value detected by the voltage sensor
and outputted through this clamp means. Therefore, since the
voltage fluctuation detected at the operation limit can be
prevented, the deviation generated in the vicinity of the operation
limit can be reduced. Thus, since there is no need to set the limit
value high, slipping of the clutch disposed in the actuator can be
stopped as quickly as possible while preventing the allowable range
of the tilting angle of the mirror surface from being narrowed, and
the clutch noise generation can be prevented.
[0013] As the limit value, at least one of a predetermined upper
limit value or a predetermined lower limit value is defined, and a
stop control means may be arranged so as to stop the actuator when
the voltage value detected by the voltage sensor exceeds the
predetermined upper limit value or drops below the predetermined
lower limit value.
[0014] If slippage occurrence is detected when the voltage value
exceeds the predetermined upper limit value or drops below the
predetermined lower limit value as described above, it becomes
possible to stop slipping of the clutch disposed in the actuator as
quickly as possible while preventing favorably the allowable range
of the tilting angle of the mirror surface from being narrowed, and
thus the clutch noise generation can be prevented.
[0015] Moreover, the electric mirror may be arranged so that a case
is provided with a mirror main body which is mounted thereto, a
mirror surface angle is adjustable with respect to the case in the
mirror main body, and the actuator drives the mirror main body so
as to adjust the mirror surface angle of the mirror main body.
[0016] As described above, the actuator drive control is performed
for adjusting the mirror surface angle on the occasion of adjusting
the mirror surface angle of the mirror main body. In that case a
problem of a slip noise occurs, but the occurrence of the slip
noise can be prevented.
[0017] According to a control method of an automobile electric
mirror of the present invention, slipping of a clutch disposed in
an actuator can be stopped as quickly as possible, and occurrence
of a clutch noise can be effectively prevented.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1 is an exploded perspective view of an electric mirror
used in an embodiment of the present invention;
[0019] FIG. 2 is an exploded perspective view of a mirror holder
and a swinging mechanism body;
[0020] FIG. 3 is a sectional view of an essential part of the
swinging mechanism body;
[0021] FIG. 4 is a circuit diagram of a mirror-surface angle
detection circuit;
[0022] FIG. 5 is a circuit diagram of the mirror-surface angle
detection circuit as a specific example;
[0023] FIG. 6 is a circuit diagram of the electric mirror;
[0024] FIG. 7a is a graph showing a waveform of a voltage value
outputted from an amplifier circuit;
[0025] FIG. 7b is a graph showing a waveform of a voltage value
outputted from an offset circuit;
[0026] FIG. 7c is a graph showing a waveform of a voltage value
outputted from a clamp circuit;
[0027] FIG. 8 is a graph showing a change in the voltage value;
[0028] FIG. 9 is an exploded perspective view of an electric
storage portion in an automobile electric mirror.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0029] A preferred embodiment of the present invention will be
described below referring to the drawings. FIG. 1 is an exploded
perspective view of an electric mirror used in the preferred
embodiment of the present invention, FIG. 2 is an exploded
perspective view of a mirror holder and a swinging mechanism body,
and FIG. 3 is a sectional view of an essential part of the swinging
mechanism body. As shown in FIG. 1, a side mirror 1, which is an
electric mirror, is provided with a cover 2 and a mirror main body
3, and the mirror main body 3 is contained within the cover 2. A
frame 4 and a swinging mechanism body 5 are provided in the cover 2
on a back face side of the mirror main body 3. The swinging
mechanism body 5 is mounted on the cover 2 through the frame 4, and
the mirror main body 3 is mounted on the surface of the swinging
mechanism body 5. The frame 4 and the swinging mechanism body 5 are
arranged on the back face side of the mirror main body 3 and
contained in the cover 2.
[0030] The swinging mechanism body 5 has a mirror body 10 as shown
in FIG. 2, and a motor 11, which is an actuator, is provided at the
mirror body 10. Moreover, a worm wheel 12 is connected to the motor
11, and an adjust nut 13 is mounted on the worm wheel 12. The
adjust nut 13 has a cylindrical body portion 13A and a spherical
head portion 13B. Moreover, the body portion 13A has a hollow
inside thereof as shown in FIG. 3, and a claw portion 13C having
elasticity is provided at its base end side. Furthermore, a male
thread member 10A is provided at the mirror body 10, and this male
thread member 10A is inserted into the body portion 13A of the
adjust nut 13. Also, the claw portion 13C in the adjust nut 13 is
engaged with the threaded portion in the male thread member 10A.
Moreover, a base member 14 is fixed to the mirror body 10, and a
through hole 14A is formed in the base member 14. The adjust nut 13
passes the through hole 14A and projects in the opposite direction
of the mirror body 10 sandwiching the base member 14
therebetween.
[0031] Also, at a position in the mirror body 10 sandwiching the
base member 14 therebetween, a pivot plate 15 is disposed. The
pivot plate 15 has a hollowed fitting portion 15A having a
spherical inner surface, as shown in FIG. 3, and the tip end of the
adjust nut 13 is fitted in this fitting portion 15A. Moreover, to
this pivot plate 15, the mirror main body 3 shown in FIG. 1 is
fixed.
[0032] Then, when the motor 11 is operated, the worm wheel 12 and
the adjust nut 13 mounted on this worm wheel 12 are rotated
according to the operating state of the motor 11. When the adjust
nut 13 is rotated, the adjust nut 13 is relatively moved close
to/separated from with respect to the cover 2, and the pivot plate
15 in which the adjust nut 13 is fitted is relatively moved close
to/separated from the cover 2. Thus a mirror surface angle of the
mirror main body 3 is adjusted. Also, if the mirror surface angle
of the mirror main body 3 exceeds an allowable range, movement of
the mirror main body 13 is suppressed. At this time, the worm wheel
12 and the adjust nut 13 continue to be rotated, but the claw
portion 13C provided at the adjust nut 13 is bent and goes over the
thread on the male thread member 10A provided on the mirror main
body 10, and the adjust nut 13 idles. When the bent claw portion
13C goes over the thread, a clutch noise is generated. The male
thread member 10A and the claw portion 13C constitute a clutch
mechanism 16.
[0033] Moreover, on the side mirror 1, a mirror surface angle
detection circuit for detecting a swing angle (mirror surface
angle) of the mirror main body 3 with respect to the cover 2 is
provided. FIG. 4 shows a circuit diagram of the mirror surface
angle detection circuit. The circuit diagram in FIG. 4 shows a
circuit for detecting a horizontal angle (angle around the vertical
axis) for the mirror surface angle of the mirror main body 3, but a
circuit for detecting a vertical angle (angle around the horizontal
axis) is also provided as a similar circuit.
[0034] As shown in FIG. 4, a mirror surface angle detection circuit
20 is provided with a constant current circuit 21, a voltage sensor
22, an amplifier circuit 23, an offset circuit 24 and a clamp
circuit 25. The constant current circuit 21 supplies a constant
current to the voltage sensor 22. The voltage sensor 22 has a
permanent magnet and a magnetic detection element for detecting a
voltage generated from a relative positional change between the
permanent magnet and the magnetic detection element with respect to
the constant current supplied from the constant current circuit 21.
Therefore, the voltage detected by the voltage sensor 22 varies
according to the mirror surface angle.
[0035] The amplifier circuit 23 amplifies the voltage detected by
the voltage sensor 22. The voltage value amplified by the amplifier
circuit 23 is outputted to the offset circuit 24. The offset
circuit 24 offsets the voltage value amplified by the amplifier
circuit 23 and adjusts it to a predetermined voltage value. The
voltage value offset by the offset circuit 24 is outputted to the
clamp circuit 25. In the clamp circuit 25, the outputted voltage
value is clamped to a predetermined upper limit value and a
predetermined lower limit value, which are 4.5V and 0.5V in the
embodiment respectively. Here, in the embodiment, the time when the
voltage value becomes 5V and 0V is defined as a state where the
mirror surface angle reaches the limit value, respectively. The
mirror surface angle detection circuit 20 shown in FIG. 4 is a
circuit as shown in FIG. 5, for a specific example.
[0036] Furthermore, as shown in FIG. 6, a control device 6 is
connected to the mirror surface angle detection circuit 20, and the
motor 11 is connected to the control device 6. The control device 6
performs opening/closing control of a switch element S by operating
a mirror operating switch SW provided at a driver's seat of an
automobile, which is not shown. By this opening/closing control, an
electric current is supplied to the motor 11, and by operating the
motor 11, the mirror surface angle of the mirror main body 3 is
adjusted.
[0037] Next, an operation of the electric mirror control device
according to the embodiment will be described. In the electric
mirror control device according to the embodiment, a voltage
detected by the voltage sensor 22 changes depending on the mirror
surface angle of the mirror, and the motor 11 is controlled by this
change of the voltage so as to suppress movement of the mirror main
body 3 exceeding an allowable range. Here, in the mirror surface
angle detection circuit 20, the voltage detected by the voltage
sensor 22 is amplified by the amplifier circuit 23, and the voltage
value is adjusted by the offset circuit 24 and thereafter, the
voltage value is clamped to a maximum value and a minimum value set
as limit values at the clamp circuit 25. For example, if the mirror
main body 3 is moved in a certain direction by operating the motor
11, when the voltage detected by the voltage sensor 22 is outputted
to the amplifier circuit 23, a change in the voltage value
outputted from the amplifier circuit 23 draws, as shown in FIG. 7a,
a waveform increasing in proportion to the operating angle of the
mirror surface angle of the mirror main body 3. When this voltage
is outputted to the offset circuit 24, the change in the voltage
value outputted from the offset circuit 24 is, as shown in FIG. 7b,
located at a position where the voltage value is offset. When this
voltage is outputted to the clamp circuit 25, the change in the
voltage value outputted from the clamp circuit 25 forms, as shown
in FIG. 7c, a waveform clamped to 4.5V, which is an upper limit
value of the voltage value, and 0.5V, which is a lower limit
value.
[0038] On the one hand, when tilting the mirror main body 3 by
driving the motor 11, if the motor 11 tries to operate exceeding
the allowable range of the mirror main body 3, the motor 11 idles
by the clutch mechanism 16. At this time, the voltage detected by
the voltage sensor 22 is in the largely oscillated state at the
time when the allowable range is exceeded as shown by a straight
line L1 in FIG. 8 before outputted by the clamp circuit 25. When
this largely oscillated voltage is detected by the voltage sensor
22, it can be determined that the allowable range has been
exceeded, but in this case, the accuracy to determine exceeding of
the allowable range is low.
[0039] On the other hand, in the electric mirror control device in
this preferred embodiment, the clamp circuit 25 is provided in the
mirror surface angle detection circuit 20. This clamp circuit 25
clamps the detected voltage value to the upper limit value and the
lower limit value, which are predetermined limit values,
respectively. Therefore, it is detected by the voltage sensor 22,
and the voltage value outputted from the clamp circuit 25 is, as
shown by a straight line L2 in FIG. 8, clamped at a position
closest to the allowable range. The control device 6 determines if
this clamped voltage value continues for a certain period of time
or not, and when it is determined that the clamped voltage value
has continued for the certain period of time, the switch element S
is controlled to be open. Therefore, the motor M can be stopped at
a position closest to the allowable range. Thus, without narrowing
the allowable range of the tilting angle of the mirror surface,
accurate detection can be made, and slipping of the clutch disposed
in the actuator is stopped as quickly as possible, consequently
generation of the clutch noise can be prevented.
[0040] In the above embodiment, an example of mirror surface angle
adjustment was described for control of an automobile electric
mirror, but the similar control can be also performed for control
of electric storage. FIG. 9 is an exploded perspective view of an
electric storage portion in the automobile electric mirror. An
electric storage portion 30 has a speed reducer 31 integrally
incorporated in the cover 2, and a motor 32 is mounted to the speed
reducer 31. An output shaft 33 is mounted to the speed reducer 31,
and a lower end of the output shaft 33 is mounted to a base member
40. The base member 40 is fixed to a body of a vehicle, which is
not shown. Also, as a position of the cover 2, a using position
standing for the use state and a stored position standing for the
fold state are specified, and by driving the motor 32, the using
position and the stored position are switched. Moreover, the speed
reducer 31 is provided with a clutch mechanism, not shown, and when
the electric storage mirror is to rotate the cover 2 exceeding the
using position or the stored position, the clutch mechanism slips
so as to shut off a power from the motor 32.
[0041] As for the motor 32 in the electric storage portion 30
having the above arrangement as well, there is a problem of clutch
noise generated while slipping of the clutch mechanism disposed in
the speed reducer 31 as with the above motor 11 for adjusting the
mirror surface angle. In order to cope with this, the generation of
the clutch noise while slipping of the clutch mechanism can be
prevented by performing the similar control as that of the control
device 6.
[0042] The preferred embodiments of the present invention have been
described so far but the present invention is not limited to the
above embodiments. For example, in the above embodiment, the motor
is used as the actuator, but other driving mechanisms may be used.
Also, the motor is stopped to stop driving of the electric mirror,
but such a mode may be adopted that the motor is disconnected from
the clutch mechanism.
* * * * *