JP2004017831A - Vehicular tread adjusting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress an increase in size and weight of an axle case itself, to simplify a structure of a drive cylinder for expand/contract driving the axle case, and to facilitate assembling/disassembling to/from the axle case. <P>SOLUTION: The axle case 12 structured to freely expand/contract by a fixed case 20 and a moving case 21 coupled to the fixed case 20 so as to slide in an axial direction is provided. A supporting element 30 is integrally provided on an outer surface portion of the fixed case 21. A cylinder main body 32 of the drive cylinder 31 expand/contract driving the axle case 12 is supported to the supporting element 30 while axial movement is regulated, and an axial outer end portion of a piston rod 34 slidably provided in the cylinder main body 32 is coupled to the moving case 21. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a wheel distance adjusting device for a vehicle such as a tractor.
[0002]
[Prior art]
Japanese Patent No. 2513870 discloses a wheel adjuster for a vehicle including a telescopic axle case and a hydraulic cylinder for expanding and contracting the axle case.
In the above prior art, the axle case includes a fixed case and a movable case slidably provided in the fixed case, and a cylindrical holding case having an axially open outside is integrally formed on the rear surface of the fixed case. Is formed.
[0003]
In the holding case, a cylinder body of a hydraulic cylinder is provided slidably in the axial direction, a piston rod is provided slidably in the cylinder body in the axial direction, and an axially outer end of the cylinder body is The movable case is fixed to an interlocking member connected to the axially outer end, and the axially inner end of the piston rod is fixed in the holding case.
Then, by moving the cylinder body in the axial direction with respect to the piston fixed in the holding case, the cylinder body moves out of the holding case, and the movable case connected to the cylinder body moves with respect to the fixed case. It was to be moved in the axial direction.
[0004]
[Problems to be solved by the invention]
In the conventional wheel adjuster described above, the holding case forms a part of the hydraulic cylinder because the holding case slidably supports the cylinder body.
For this reason, the holding case must be formed long in the axial direction so as to be able to accommodate the entire cylinder body, and the axle case integrally formed with the holding case has been increased in size and weight. In addition, the entire inside of the holding case formed long in the axial direction must be strictly finished, and the structure of the hydraulic cylinder itself is extremely complicated, such as forming an oil passage in the piston rod. Due to the factors, the production cost had risen.
[0005]
Also, when assembling the hydraulic cylinder to the rear axle case, the rear axle case had to be assembled together with other parts with the rear axle case removed from the tractor, so assembly work was complicated. When the main body is disassembled, the entire axle case must be disassembled, so the maintenance is very poor.
SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to reduce the size and weight of the axle case itself, to simplify the structure of a drive cylinder for extending and retracting the axle case, It is an object of the present invention to provide a vehicle wheel adjuster capable of easily assembling and disassembling a case.
[0006]
[Means for Solving the Problems]
The present invention employs the following technical means to achieve the above object.
In other words, the vehicle wheel adjuster according to the present invention includes an axle case configured to be extendable and contractible by a fixed case and a movable case slidably connected to the fixed case in an axial direction, and an outer surface of the fixed case. A piston rod is provided integrally with the support, supports a cylinder body of a drive cylinder for driving the axle case to extend and contract, in a state where axial movement is restricted, and a piston rod slidably provided in the cylinder body. Is connected to the movable case.
[0007]
According to this, the support formed integrally with the axle case does not support the cylinder body slidably as in the related art (it does not constitute a part of the drive cylinder), but operates independently. It merely supports the drive cylinder, in other words, the drive cylinder is external to the axle case (support). Therefore, it is not necessary to form the support body long in the axial direction, and it is possible to suppress an increase in the size and weight of the axle case integrally formed with the support body. Further, the structures of the support and the drive cylinder can be simplified, and the assembly and disassembly of the drive cylinder with respect to the support can be easily performed.
[0008]
In the above configuration, the support preferably supports an axially outer end of the cylinder body, and an axially inner end of the cylinder body projects axially inward from the support.
The rotation of the movable case accompanying the rotation of the axle is prevented by the drive cylinder supported by the support. At this time, the drive cylinder has its axial outer end supported by the support. Therefore, a bending moment or the like due to a load from the movable case side is suppressed, and strong support is possible.
[0009]
Further, in the above configuration, if the inner end in the axial direction of the cylinder body is connected to the inner side in the axial direction of the fixed case, the cylinder body is supported at two points by the support and the fixed case. Thus, a stronger support structure can be obtained.
It is preferable that the cylinder body is configured to be divided into two parts in the axial direction.
More specifically, it is preferable that the first component and a second component fitted into the first component from the outside in the axial direction are configured to be divided into two parts in the axial direction. The body is inserted from the outside in the axial direction with respect to the cylindrical support, and the engaged portion formed on the outer peripheral portion thereof is engaged with the engaging portion formed on the inner peripheral portion of the support. The movement in the axial direction inward is restricted, and the second component is fitted in the first component in the cylinder of the support, and is moved outward in the axial direction by the retaining member attached to the support. It is recommended that is regulated.
[0010]
Since the cylinder body is divided into two parts in the axial direction as described above, the cylinder body can be easily disassembled, and the maintenance of the drive cylinder is improved. In addition, since the first and second components are connected in the cylinder of the support, the second component can be removed while the first component is attached to the support. It's easy. Further, by the engagement between the engaging portion and the engaged portion, the movement of the cylinder body (first component) inward in the axial direction can be restricted by a simple structure.
It is preferable that a detent member for stopping the rotation of the cylinder body with respect to the support is provided between the support and the cylinder body.
[0011]
Thereby, when the piping port is formed in the cylinder body, the position in the circumferential direction does not shift.
The axle rotatably supported by the axle case is fitted to a first shaft portion, a second shaft portion provided coaxially with the first shaft portion, and the first and second shaft portions. A connecting shaft portion connected to both shaft portions so as to be rotatable together, and connected to one of the first and second shaft portions so as to be slidable in the axial direction and to be movable relative to the other in the axial direction. A restricting member for restricting axial relative movement with respect to the other shaft portion is attached to the connecting shaft portion, and a circumferential engagement groove for engaging the restricting member is formed on the other shaft portion. Is preferred.
[0012]
According to this, when connecting the connecting shaft portion and the other shaft portion by spline fitting or the like, it is possible to engage the regulating member with the circumferential engaging groove without strictly adjusting the mutual circumferential position. It becomes possible, and the assembling work of the axle can be easily performed.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows the left half of the rear axle of a tractor employing the wheel adjuster according to the embodiment of the present invention. A rear axle case 12 is attached to both sides of the rear of the transmission case 11 of the tractor. A rear axle 13 is rotatably supported by the case 12, and a rear wheel is attached to an axially outer end (left side in FIG. 1) of the rear axle 13.
[0014]
The rear axle 13 is linked to a differential yoke shaft 14 projecting from a rear wheel differential device in the transmission case 11 via a final reduction gear 15, and the differential yoke shaft 14 is provided with a brake device 16.
The rear axle case 12 includes a fixed case 20 fixed to the transmission case 11 and a movable case 21 slidably inserted in a cylinder of the fixed case 20 in the axial direction. Is configured to be able to expand and contract by sliding in the axial direction with respect to.
[0015]
The rear axle 13 includes a first shaft portion 22 connected to the final reduction gear 15, a second shaft portion 23 disposed coaxially outside the first shaft portion 22 in the axial direction, And a connection shaft portion 24 for connecting the second shaft portions 21 and 22.
The connecting shaft portion 24 is formed in a cylindrical shape and is spline-fitted to the outer peripheral portions of the first and second shaft portions 22 and 23, and can transmit the rotational power from the first shaft portion 22 to the second shaft portion 23. is there. The connecting shaft 24 is connected to the first shaft 22 so as to be slidable in the axial direction, while the outer circumferential surface of the inner end of the second shaft 23 in the axial direction is provided with a circumferential engaging groove. The second shaft portion 23 and the connection shaft portion 24 are formed by engaging the distal end portion of a regulating member 26 formed of a bolt screwed from the outer peripheral surface side of the connection shaft portion 24 into the engagement groove 25. Are restricted.
[0016]
The rear axle 13 is configured to be able to expand and contract in the axial direction by the configuration of the first and second shaft portions 22 and 23 and the connection shaft portion 24 as described above.
Conventionally, the restricting member 26 is screwed into a female screw hole formed in the connection shaft portion 24, and is attached by inserting its tip into an engagement hole formed in the second shaft portion 23. The second shaft portion 23 and the connection shaft portion 24 must be spline-fitted so that their circumferential relative positions with the engagement holes match, and the operation is troublesome.
On the other hand, as in the present embodiment, by forming a circumferential engaging groove 25 in the second shaft portion 23 and engaging the distal end of the regulating member 26 with the engaging groove 25, The restriction member 26 can be attached by spline-fitting the two shaft portions 23 and the connection shaft portion 24 without being aware of the circumferential positions thereof, and the connection work is significantly simplified.
[0017]
A cylindrical support 30 penetrating in the left-right direction (axial direction) is integrally formed on the rear surface of the outer end portion in the axial direction of the fixed case 20, and the support 30 includes the rear axle case 12 and A drive cylinder 31 composed of a hydraulic cylinder for driving the rear axle 13 to expand and contract is mounted.
The drive cylinder 31 has a bottomed cylindrical cylinder body 32 having an axially open outer end, a piston 33 slidably inserted into the cylinder body 32, and an axially inner end The cylinder body 32 has a piston rod 34 which is fixed to the piston 33 and moves along with the axial movement of the piston 33. The cylinder body 32 has an axially outer end side inserted into and supported by the support 30.
[0018]
The length of the support 30 in the axial direction is shorter than the length of the cylinder body 32 in the axial direction. Therefore, the inner end of the cylinder body 32 in the axial direction protrudes from the support 30.
The distal end of the piston rod 34 is detachably connected via a screw portion 36 and a nut 37 to an interlocking member 35 projecting radially outward from the axially outer end of the movable case 21. The movable case 21 moves in the axial direction by the movement in the axial direction of 34, and accordingly, the second shaft portion 23 and the connecting shaft portion 24 also move in the axial direction. As a result, the rear axle 13 expands and contracts, and the wheel span of the left and right rear wheels is adjusted.
[0019]
As described above, by supporting the outer end portion of the cylinder body 32 in the axial direction by the support body 30, a load in a direction that follows the rotation of the rear axle 13 is applied to the cylinder body 32 via the movable case 21. However, the bending and torsional moment applied to the cylinder body 32 are reduced, which is advantageous in strength.
Further, since the support 30 is shorter than the cylinder body 32 and supports only the axially outer end side of the cylinder body 32, the rear axle case 12 (fixed case 20) including the support 30 can be enlarged. The weight increase can be suppressed as much as possible, the processing inside the support 30 is easy, the structure is simple, and the cost can be reduced.
[0020]
Further, since the drive cylinder 31 is externally attached to the fixed case 20 via the support 30, the assembling and removal thereof are easy, maintenance is easy, and the configuration can be simplified.
The cylinder main body 32 is configured to be divided into two in the axial direction by a first component 41 and a second component 42.
The first component 41 constitutes the inside in the axial direction of the cylinder body 32, and the second component 42 constitutes the outside in the axial direction, and the second component 42 is provided on the outer end side in the axial direction of the first component 41. Both are connected by fitting the inner end in the axial direction. In a connection portion between the two components 41 and 42, a seal member 43 for sealing between the first component 41 and the peripheral groove formed on the outer peripheral surface of the second component 42 is provided.
[0021]
A seal member 44, a bush, and the like are provided between the inner peripheral portion of the second component 42 and the piston rod 34.
At the outer end in the axial direction of the first component 41, an engaged portion 45 protruding in the radial direction is formed in the circumferential direction. On the other hand, in the cylinder at the inner end in the axial direction of the support 30, An engaging portion 46 protruding in the radial direction is formed in the circumferential direction. The cylinder body 32 is inserted into the support 30 from the outside in the axial direction, and the movement in the axial direction is restricted by the engagement of the engaged portion 45 with the engagement portion 46 in the support 30. It is supposed to be.
[0022]
The second component 42 is set so that its inner diameter can slidably support the piston rod 34, and the outer diameter of the axially inner portion is fitted into the cylinder of the first component 41. The first component 41 is formed so as to conform to the inner diameter, and the outer diameter of the axially outer portion thereof is substantially the same as the outer diameter of the engaged portion 45.
The cylinder body 32 is inserted into the support 30 from the outside in the axial direction, and is moved inward in the axial direction by engaging the engaged portion 45 of the first component 41 with the engagement portion 46 of the support. By attaching a retaining ring (prevention member) 47 to the inner periphery of the support 30 on the outside in the axial direction of the cylinder body 32, the movement in the axially outward direction is restricted.
[0023]
When assembling the cylinder body 32 to the support 30, the first and second components 41 and 42 may be assembled in a state of being connected in advance, or the first component 41 may be attached to the support 30. The two components 41 and 42 may be separately assembled so that the first component 41 is fitted by inserting the second shaft portion 42 from outside in the axial direction of the support 30 and then fitting the second shaft portion 42 to the first component 41.
On the outer surface of the first component 41, a hydraulic port 48 to which a hydraulic pipe is connected is formed to protrude at two locations in the axial direction, and an oil passage 49 communicating with the hydraulic port 48 is formed on the wall surface of the first component 41. Is formed. The inside of the first component 41 on both sides of the piston 33 is configured as oil chambers 50 and 51.
[0024]
When inserting the first component 41 into the support 30, a relief groove 52 extending in the axial direction is formed in the rear surface of the support 30 to avoid interference with the hydraulic port 48.
A locking member 53 composed of a bolt is screwed from the outer surface of the support member 30 to the escape groove 52 forming portion, and the tip of the locking member 53 is connected to the outer surface of the first component 41 (the engaged portion). 45). Thus, the rotation of the cylinder body 32 with respect to the support 30 is prevented, and the hydraulic port 48 can be fixed so as not to move in the circumferential direction.
[0025]
An axial inner end 42B of a fitting portion (fitting tubular portion 42A) of the second component 42 to the first component 41 projects inward from the inner peripheral surface of the first component 41 to partition the oil chamber 50. The wall 42B constitutes a restricting portion for setting a limit of movement of the piston 33 outward in the axial direction. Therefore, there is no need to separately provide a member for setting the movement limit of the piston 33, and the structure is simplified.
By configuring the cylinder main body 32 into two parts in the axial direction, maintenance of the cylinder main body 32 is facilitated. For example, it is also possible to remove and disassemble only the second component 42 while the first component 41 is attached to the support 30, thereby making it possible to attach and detach replacement parts such as seals attached to the second component 42. Easy to do.
[0026]
When only the second component 42 is removed, the piston 33 can be automatically disengaged from the first component 41 by pushing the piston 33 outward in the axial direction by hydraulic pressure, which makes disassembly easier. Become.
In the drive cylinder 31, the axial inner end of the cylinder body 32 may be connected to the axial inner end of the fixed case 20. For example, as shown by a two-dot line in FIG. 3, a connecting piece 20A protrudes from the fixed case 20, and the inner end of the cylinder body 32 is detachably connected to the connecting piece 20A by a connecting tool 20B such as a pin. In this case, the cylinder main body 32 is supported at two points by the support body 30 and the connecting piece 20A, so that a stronger support structure is obtained. In this case, since the rotation of the cylinder body 32 with respect to the support 30 is prevented by the connection to the connection piece 20A, the rotation stop member 53 can be omitted.
[0027]
The present invention is not limited to the above embodiment, and the design can be changed as appropriate.
For example, the wheel adjuster can be provided corresponding to the front axle of the tractor, or can be applied to a work vehicle other than the tractor. Further, the present invention is not limited to the form in which the support 30 and the drive cylinder 31 are provided on the rear surface of the axle case 12. The drive cylinder 31 is not limited to a hydraulic type, and can be replaced with a pneumatic type, a mechanical type (screw type), or the like.
[0028]
【The invention's effect】
As described above in detail, according to the present invention, it is possible to suppress an increase in the size and weight of the axle case itself, to simplify the structure of a drive cylinder for extending and retracting the axle case, and to assemble and disassemble the axle case. It will be easy to do.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a left half of a rear axle case of a tractor employing a wheel adjuster according to an embodiment of the present invention.
FIG. 2 is a plan cross-sectional view of the wheel adjuster.
FIG. 3 is a sectional view taken along the line AA of FIG. 1;
[Explanation of symbols]
12 Rear axle case (axle case)
13 Rear axle (axle)
Reference Signs List 20 fixed case 21 movable case 22 first shaft portion 23 second shaft portion 24 connecting shaft portion 25 engaging groove 26 regulating member 30 support member 31 drive cylinder 32 cylinder body 33 piston 34 piston rod 41 first component 42 second configuration Body 45 Engaged part 46 Engagement part 53 Lock member

Claims (7)

An axle case (12) configured to be extendable and contractable by a fixed case (20) and a movable case (21) slidably connected to the fixed case (20) in an axially slidable manner. A support (30) is integrally provided on the outer surface, and the support (30) supports the cylinder body (32) of the drive cylinder (31) that expands and contracts the axle case (12) while restricting the axial movement thereof. And an axially outer end of a piston rod (34) slidably provided in the cylinder body (32) is connected to the movable case (21). apparatus The support (30) supports an axially outer end of the cylinder body (32), and an axially inner end of the cylinder body (32) projects axially inward from the support (30). The wheelbase adjusting device for a vehicle according to claim 1, wherein 3. The vehicle wheel adjuster according to claim 2, wherein an axial inner end of the cylinder body (32) is connected to an axial inner end of the fixed case (20). The wheel adjuster according to any one of claims 1 to 3, wherein the cylinder body (32) is configured to be divided into two parts in the axial direction. The cylinder body (32) is constituted by a first component (41) and a second component (42) fitted into the first component (41) from the outside in the axial direction so as to be divided into two parts in the axial direction. The first component (41) is inserted into the cylindrical support (30) from the outside in the axial direction, and engages the engaged portion (45) formed on the outer periphery thereof with the support (30). The movement in the axially inward direction is restricted by engaging with an engaging portion (46) formed on the inner peripheral portion of the cylinder, and the second component (42) is moved in the cylinder of the support (30). The axially outward movement is restricted by a retaining member (47) fitted to the first structure (41) and attached to the support (30). Wheel adjuster for vehicle. A detent member (53) is provided between the support (30) and the cylinder body (32) to prevent the cylinder body (32) from rotating with respect to the support (30). A vehicle wheel adjuster according to any one of claims 1 to 5. An axle (13) rotatably supported by the axle case (12) comprises a first shaft (22) and a second shaft (23) provided coaxially with the first shaft (22). ) And the first and second shaft portions (22, 23) are fitted to each other so that both shaft portions (22, 23) are rotatably connected together, and one of the first and second shaft portions (22, 23). And a connecting shaft (24) connected to the other shaft so as to be slidable in the axial direction and not to move relative to the other in the axial direction. The connecting shaft (24) is connected to the other shaft. A regulating member (26) for regulating relative movement in the axial direction with the portion (23) is attached, and a circumferential engaging groove (25) in which the regulating member (26) is engaged with the other shaft portion (26). The wheel-wheel-range adjusting device for a vehicle according to any one of claims 1 to 6, wherein:

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