U.S. patent application number 09/973051 was filed with the patent office on 2002-02-21 for piping structure of a working machine.
This patent application is currently assigned to SHIN CATERPLLAR MITSUBISHI LTD.. Invention is credited to Iwamoto, Takahiro, Matsumoto, Toshiyuki, Nishikawa, Hiroyasu.
Application Number | 20020020448 09/973051 |
Document ID | / |
Family ID | 18587566 |
Filed Date | 2002-02-21 |
United States Patent
Application |
20020020448 |
Kind Code |
A1 |
Nishikawa, Hiroyasu ; et
al. |
February 21, 2002 |
Piping structure of a working machine
Abstract
A piping structure of a working machine, which prevents the
piping at a coupling portion where a pair of members are swingable
coupled together via a shaft, from being damaged. The piping
structure comprises a swivel joint which is a rotary joint for
fluid and is disposed, on the outer side in the radial direction of
a shaft of a coupling portion where a pair of members are swingable
coupled together via said shaft, so as to swing on axis of swinging
motion as a center of rotation.
Inventors: |
Nishikawa, Hiroyasu; (Tokyo,
JP) ; Iwamoto, Takahiro; (Tokyo, JP) ;
Matsumoto, Toshiyuki; (Osaka, JP) |
Correspondence
Address: |
MILLEN, WHITE, ZELANO & BRANIGAN, P.C.
2200 CLARENDON BLVD.
SUITE 1400
ARLINGTON
VA
22201
US
|
Assignee: |
SHIN CATERPLLAR MITSUBISHI
LTD.
Tokyo
JP
|
Family ID: |
18587566 |
Appl. No.: |
09/973051 |
Filed: |
October 10, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
09973051 |
Oct 10, 2001 |
|
|
|
PCT/JP00/06648 |
Sep 27, 2000 |
|
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Current U.S.
Class: |
137/580 ;
285/272; 285/275; 285/61 |
Current CPC
Class: |
E02F 3/3618 20130101;
E02F 3/3627 20130101; E02F 9/2271 20130101; Y10T 137/86268
20150401; F16L 39/04 20130101; E02F 3/3663 20130101; E02F 9/2275
20130101 |
Class at
Publication: |
137/580 ; 285/61;
285/272; 285/275 |
International
Class: |
F16L 027/00 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 13, 2000 |
JP |
2000-68518 |
Claims
1. A piping structure of a working machine, comprising a swivel
joint which is a rotary joint for fluid and is disposed, on the
outer side in the radial direction of a shaft of a coupling portion
where a pair of members are swingably coupled together via said
shaft, so as to swing on the axis of swinging motion as a center of
rotation.
2. A piping structure of a working machine according to claim 1,
wherein said swivel joint comprises a cylindrical stator mounted on
either one of said pair of members and a rotor rotatably fitted to
the outer periphery of said stator.
3. A piping structure of a working machine according to claim 2,
wherein a cylindrical boss to which the stator is fitted is
provided between said stator and said shaft, said boss being
provided on either one of said pair of members.
4. A piping structure of a working machine according to any one of
claims 1 to 3, wherein said pair of members are an arm provided for
said working machine and a working device swingably coupled to said
arm.
Description
TECHNICAL FIELD
[0001] The present invention relates to a piping structure of a
working machine. More specifically, the invention relates to a
piping structure of a working machine, in which a swivel joint that
is a rotary joint for fluid is provided at a coupling portion where
a pair of members of a working machine are swingable coupled
together via a shaft.
BACKGROUND ART
[0002] Referring to FIG. 7, various working devices, such as a
working device 52 equipped with a quick coupler 51, is swingably
attached to an end of an arm 50 of a hydraulic shovel which is a
typical working machine, by using a shaft 54. By a swing operation
link 53 provided for the arm 50, the working device 52 swings
between a lower position shown by a solid line and an upper
position shown by a two-dot chain line. The working device 52 is
provided with a hydraulic cylinder 51a that is a fluid pressure
actuator, and the hydraulic cylinder 51a and an arm 50 are coupled
together through a hydraulic piping 56. A flexible hydraulic hose
56a is used for the hydraulic piping 56 in the coupling portion so
as to be able to follow the swinging working of the working device
52, one end thereof being connected to a piping 56b fixed to the
arm 50 and the other end thereof being connected to the hydraulic
cylinder 51a of the working device 52. The illustrated hydraulic
cylinder 51a is of the double-acting type, and a total of two
pipings 56 are provided, one on the head side H and the other one
on the rod side R.
DISCLOSURE OF THE INVENTION
[0003] The piping structure of the conventional working machine of
the above-mentioned construction, however, involves problems as
described below.
[0004] That is, when the working device 52 swings at an end of the
arm 50, the hose 56a bends between a "stretched state (indicated by
a solid line)" in which both ends thereof are separated away from
each other and a "slackened state (indicated by a two-dot chain
line)" in which both ends thereof are brought close to each other
due to the swinging motion of the working device 52. When bent, the
hose 56a is liable to come in contact with the arm 50 or the
working device 52. In the "slackened state" in particular, the hose
56a hangs down between the arm 50 and the working device 52 or
extends over a side portion of the arm 50, often being caught
between the arm 50 and the working device 52 or coming in contact
with the surrounding obstacles. Consequently, the life of the hose
is shortened or the hose is damaged.
[0005] The present invention has been made in view of the
above-mentioned fact, and its technical assignment is to provide a
piping structure of a working machine, which makes it possible to
prevent the piping at a coupling portion where a pair of members
are swingably coupled together via a shaft, from being damaged.
[0006] In the present invention, as a piping structure of a working
machine to solve the above-mentioned technical assignment, there is
provided a piping structure of a working machine, comprising a
swivel joint which is a rotary joint for fluid and is disposed, on
the outer side in the radial direction of a shaft of a coupling
portion where a pair of members are swingably coupled together via
said shaft, so as to swing on the axis of swinging motion as a
center of rotation.
[0007] In the piping structure of the working machine according to
the present invention, a swivel joint is provided at the coupling
portion where the pair of members are swingably coupled together.
Therefore, since the piping between the pair of members is arranged
via the swivel joint, it does not need to use the flexible piping
such as the hose.
[0008] In a preferred embodiment, the swivel joint comprises a
cylindrical stator mounted on either one of said pair of members
and a rotor rotatably fitted to the outer periphery of the
stator.
[0009] The swivel joint is constituted by a stator and a rotor
arranged on the outer side of the shaft that couples the pair of
members.
[0010] According to a preferred embodiment, further, a cylindrical
boss to which the stator is fitted is provided between the stator
and the shaft, the boss being attached to either one of said pair
of members.
[0011] The mounting of the swivel joint on the coupling portion is
guided by the boss. Further, a thrust force acting on the pair of
members in the axial direction is received by the boss, so that an
excessive large force will not act on the swivel joint.
[0012] In a preferred embodiment, the pair of members are an arm
equipped with the working machine and a working device swingably
coupled to the arm.
[0013] The piping between the arm of the working machine and the
working device coupled to the arm is prevented from being
damaged.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is a side view of a coupling portion of an arm and a
working device in a working machine having a piping structure
constituted according to the present invention;
[0015] FIG. 2 is a front view of a coupling portion of when FIG. 1
is viewed in a direction of an arrow A-A;
[0016] FIG. 3 is a side view of a swivel joint of when FIG. 2 is
viewed in a direction of an arrow B-B;
[0017] FIG. 4 is a sectional view of when FIG. 3 is viewed in a
direction of an arrow C-C;
[0018] FIG. 5 is a sectional view of when FIG. 3 is viewed in a
direction of an arrow D-D;
[0019] FIG. 6 is a sectional view illustrating another mounting
state of mounting a stator of the swivel joint of when FIG. 3 is
viewed in the direction of the arrow D-D; and
[0020] FIG. 7 is a side view illustrating a conventional piping
structure.
BEST MODE FOR PRACTICING THE INVENTION
[0021] A piping structure of a working machine constituted
according to the present invention will now be described in detail
with reference to the accompanying drawings.
[0022] Referring to FIGS. 1 and 2, a hydraulic shovel that is a
typical working machine includes an arm 2 which is one of a pair of
members to be swingably coupled, and a working device 4 which is
the other of the pair of members swingably coupled to the arm 2. A
shaft 6 is inserted in a bearing hole 2b formed in a boss 2a at an
end of the arm 2 and in bearing holes 4b and 4b of a pair of bosses
4a and 4a of the working device 4 positioned at both ends in the
axial direction of the boss 2a, to swingably couple the working
device 4 with the arm 2. A pair of swivel joints 8 and 9 which are
rotary joints for fluid, are provided between the boss 2a of the
arm 2 and the bosses 4a of the working device 4 in the direction of
axis X of the coupling portion, on the outer side in the radial
direction of the shaft 6, so as to swing on the axis X as a center
of rotation. The working device 4 has a bucket device 4b having a
quick coupler 4a. By a swing operation link 10 provided for the arm
2, the working device 4 is caused to swing on the axis X as a
center between a downwardly swinging position (indicated by a solid
line) and an upwardly swinging position (indicated by a two-dot
chain line) as shown in FIG. 1.
[0023] The working device 4 is equipped with a hydraulic cylinder 5
of the double-acting type. A piping 12a provided for the arm 2 is
connected by a piping 12b to a rod end R of the hydraulic cylinder
5 via one swivel joint 8. A piping 13a provided for the arm 2 is
connected to a head end H by a piping 13b via another swivel joint
9.
[0024] In this embodiment, the hydraulic cylinder 5 of the
double-acting type is used for the working device 4 and hence, a
pair of swivel joints 8 and 9 are used for connecting two pipings.
The swivel joints 8 and 9 may be constituted in substantially the
same manner. Therefore, the swivel joint 8 only is described below
in detail.
[0025] Referring to FIGS. 3 and 4, the swivel joint 8 will be
explained. The swivel joint 8 comprises a cylindrical stator 14
arranged on the outer side of the shaft 6 in the radial direction
and a rotor 16 rotatably fitted to the outer periphery of the
stator 14. The stator 14 is mounted on the working device 4. A
cylindrical boss 18 is provided between the stator 14 and the shaft
6.
[0026] The cylindrical stator 14 has a slide portion 14a of which
the outer periphery is slidably fitted to the rotor 16 and a flange
portion 14b formed at one end in the axial direction X (right end
in FIG. 4) and having a diameter larger than that of the slide
portion 14a. A pair of annular sealing grooves 14c having a
rectangular shape in cross section are formed in the outer
periphery of the slide portion 14a, spaced at a distance in the
direction of axis X. An annular flow path 14d having a rectangular
shape in cross section is formed between the sealing grooves 14c
and 14c in the direction of axis X. A connection port P1 for fluid
is formed in the outer periphery of the flange portion 14b. The
port P1 is connected to the annular flow path 14d via a flow path
14e formed in the stator 14. Three threaded holes 14f are formed in
the end surface on the side of the slide portion 14a of the stator
14 along a pitch circle with the axis X as a center. The inner
periphery of the stator 14 has a diameter that freely fits at a
minimal gap to the outer periphery of the cylindrical boss 18.
[0027] A disk-like holder plate 20 is attached to the end surface
of the stator 14 having the threaded holes 14f formed therein, by
using three bolts 21 so that the movement in the axial direction X
of the rotor 16 that is fit to the outer periphery of the slide
portion 14a is limited between the holder plate 20 and the flange
portion 14b.
[0028] Annular sealing members 15 are mounted in the pair of
sealing grooves 14c and 14c to prevent the fluid in the annular
flow path 14d from leaking to the outer side. The sealing members
15 are known ones having a sealing lip formed of a synthetic rubber
or the like.
[0029] The rotor 16 has a cylindrical rotor body 16a, of which a
length in the axial direction X is a size that is slidably held
between the flange portion 14b and the holder plate 20 on the outer
periphery of the slide portion 14a of the stator 14. The inner
periphery of the rotor body 16a has a surface that is so finished
as to slide relative to the sliding portion 14a of the stator 14
and to permit the slide of the sealing member 15 mounted on the
stator 14. A boss 16b in which a connection port P2 for fluid is
formed is mounted on the outer periphery of the rotor body 16a. In
the main body 16a and the boss 16b is formed a flow path 16c
penetrating in the radial direction to communicate the port P2 with
the annular flow path 14d of the stator 14.
[0030] The inner periphery of the cylindrical boss 18 forms a
bearing hole for the shaft 6. The outer periphery of the
cylindrical boss 18 has a size that freely fits to the inner
periphery of the stator 14 at a minimal gap. An end of the boss 18
in the axial direction X (right end in FIG. 4) is mounted on the
working device 4 as a unitary structure by a suitable means such as
welding. The length of the boss 18 in the axial direction X is
defined to be slightly larger than the length of a state where the
holder plate 20 is attached to the stator 14.
[0031] A mounting portion where the stator 14 is mounted on the
working device 4 will be described with reference to FIGS. 3 and 5.
On the outer periphery of the flange portion 14b of the stator 14,
there is provided a mounting portion 14g is formed in a rectangular
form by extending an end surface of the stator 14 on the side of
the flange portion 14b in the radial direction. Two bolt holes are
formed in the mounting portion 14g. Bolts 22 are passed through the
bolt holes and are screwed into the threaded holes formed in the
working device 4 so as to mount the stator 14 on the working device
4.
[0032] As will be easily understood with reference to FIG. 4, the
connection ports P1 and P2 for fluid of the swivel joint 8
constituted as described above are communicated with each other
through the flow path 14e in the stator 14, annular flow path 14d
and flow path 16c in the rotor 16. This communication state is
maintained at all times even when relative positions of the stator
14 and the rotor 16 are changed in the direction of rotation on the
axis X as a center.
[0033] With reference to FIGS. 1 to 5, description will be given of
the mounting of the swivel joints 8 and 9 onto a portion which
couples the arm 2 and the working device 4 together, and of
connection of pipings to the swivel joints 8 and 9.
[0034] (1) Mounting the Swivel Joints on the Working Device
[0035] Prior to coupling the working device 4 to the end of the arm
2 by the shaft 6, the swivel joint 8 is mounted on the working
device 4 by fitting the stator 14 to the boss 18 provided on the
working device 4 and by securing the mounting portion 14g to the
working device 4 with bolts 22. Another swivel joint 9 is also
mounted on the working device 4 in the same manner.
[0036] (2) Coupling the Arm and the Working Device Together
[0037] The shaft 6 is inserted in the pair of bearing holes 4b and
4b of the working device 4 on which the swivel joints 8 and 9 are
mounted and in the bearing hole 2b of the arm 2 in concentric with
the axis X thereof, thereby to couple the arm 2 and the working
device 4 together.
[0038] (3) Piping
[0039] The piping 12a on the side of the arm 2 is connected to the
connection port P2 of the swivel joint 8, and the piping 12b on the
side of the working device 4 is connected to the connection port
P1. Similarly, the piping 13a on the side of the arm 2 is connected
to the piping 13b on the side of the working device 4 via the
swivel joint 9.
[0040] In this embodiment, the swivel joints 8 and 9 are provided
at the portion where the pair of members are swingably coupled
together, i.e. the arm and the working device 4 are swingably
coupled together. Therefore, even when the working device 4 swings
relative to the arm 2, no relative change between the piping 12a on
the side of the arm 2 and the connection port P1 occurs. Therefore,
a pipe member such as a steel pipe is used as the piping 12a.
Though there is no relative change between the working device 4 and
the connection port P2, the piping 12b is directly connected to the
hydraulic cylinder 5 in this embodiment and hence, a hose is used
as the piping 12b. Similarly, a pipe member such as a steel pipe is
used as the piping 13a and a hose is used as the piping 13b.
[0041] The action of the piping structure of the above-mentioned
working machine will now be described with reference to FIGS. 1 to
5.
[0042] (1) Prevention of Damage to the Piping:
[0043] Since the swivel joints 8 (9) is provided at the coupling
portion where the arm 2 and the working device 4 are coupled
together by the shaft 6, in such a manner that the center of
rotation is in concentric with the axis X of the shaft 6, the
piping connected to the swivel joint 8 (9) is not affected by the
swinging motion of the working device 4. Therefore, there is no
need of using a hose that can bend in conformity with the swinging
motion of the working device 4 unlike that of the prior art and
hence, there occurs no hanging or extension of the hose. Further,
the piping can be mounted in a fixed manner and hence, a pipe
member such as a steel pipe can be used, making it possible to
effectively prevent damage to the piping used under severe
conditions of the working machine, such as a portion where the arm
and the working device are coupled together. Further, durability of
the piping can be improved.
[0044] (2) Freedom for Piping
[0045] The connection ports P1 and P2 of the swivel joint 8 (9) can
be freely positioned in the direction of rotation on the axis 6 as
a center. Therefore, the piping can be installed at any positions
such as on the side surface or on the upper surface of the arm to
fit the specifications and shape of the working machine, arm, and
working device.
[0046] (3) Strong Swivel Joint
[0047] The outer peripheral shape of the swivel joint 8 (9) can be
formed in any shape substantially the same as the shape of the arm
or the working device at the coupling portion. Therefore, the
swivel joint 8 (9) is structurally strong and is little likely to
be damaged by foreign matters or obstacles. Further, since the
thrust load from the working device 4 in the axial direction X is
received by the boss 18 that is inserted in the swivel joint 8 (9),
the thrust load does not act on the swivel joint 8 (9) which
therefore is prevented from being damaged by the thrust load.
[0048] (4) Easy mounting:
[0049] The boss 18 works to automatically bring the center of
rotation of the swivel joint 8 (9) to be in alignment with the axis
X of the shaft 6 and hence, facilitates the mounting of the swivel
joint.
[0050] (5) Mounting the Swivel Joints on the Working Device
[0051] When the swivel joint 8 (9) is mounted on the working device
4, the arm 2 may be the one having standard specifications. This
makes it possible to suitably mount the working device on plural
working machines equipped with a standard arm without the need of
modifying the arm. Therefore, the general applicability of the
working machine can be enhanced.
[0052] Though the invention was described above in detail by way of
an embodiment, it should be noted that the invention is in no way
limited to the above embodiment only but can be varied or modified
in a variety of ways without departing from the scope of the
invention.
[0053] (1) Mounting the Swivel Joints onto the Arm
[0054] In the embodiment of the invention, the swivel joint 8 (9)
is mounted on the working device 4 which is one of a pair of
members, but may be mounted on the arm 2 which is the other member
of the pair of members as shown in FIG. 6. That is, the boss 2a of
the arm 2 is provided with a mounting portion 2b having a threaded
hole, and the mounting plate 14g of the stator 14 is secured to the
mounting portion 2b with bolts 22, whereby the swivel joint 8 (9)
is mounted on the arm 2. By mounting the swivel joint 8 (9) on the
arm 2, the arm of the working machine is provided with the swivel
joint and hence, any standard working device can be suitably
mounted on the arm.
[0055] (2) Mounting the Cylindrical Boss onto the Arm
[0056] In the embodiment of the present invention, the cylindrical
boss 18 is mounted on the working device 4. As shown in FIG. 6,
however, the cylindrical boss 18 may be mounted on the arm 2.
Further, it is allowable to mount the cylindrical boss on the arm 2
in FIG. 4 or to mount it on the working device 4 in FIG. 6.
[0057] (3) Number of Swivel Joints at the Coupling Portion
[0058] In the embodiment of the invention, the swivel joints are
provided in a total number of two at each of both ends of the shaft
6 of the coupling portion. However, when only one piping is
required for the actuator of the working device 4, the swivel joint
may be provided in a number of one on either side. When many
pipings are required for the actuators, a single swivel joint may
be provided with plural annular flow paths, thereby to provide
plural connection ports to allow them to connect with plural
pipings.
[0059] According to the piping structure of the working machine
constituted according to the present invention, there is provided a
piping structure of the working machine, which can prevent the
piping at the coupling portion where a pair of members are
swingably coupled together via a shaft, from being damaged.
* * * * *