JP2015081009A - Swash plate operating device for hydraulic pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a swash plate operating device for a hydraulic pump, which can easily perform the neutral adjustment of the hydraulic pump in a short period of time.SOLUTION: A swash plate operating device for a hydraulic pump comprising a shaft operating member for operating a swash plate operating shaft about a shaft core to operate a swash plate of the hydraulic pump, a pair of cams provided in the shaft operating member and arranged separately on both sides of the swash plate operating shaft, a contact member that comes into contact with the cams, an attachment base on which the contact member is securely attached, and a neutral spring for energizing the attachment base so as to press the contact member against the cams is configured so that the attachment base moves against the energization force of the neutral spring with the contact member being pressed by the by cams when, in a neutral position of the swash plate operating shaft, both of the pair of the cams come into contact with the contact member and the shaft operating member is rotationally operated about the shaft core of the swash plate operating shaft, in which the contact member is pivotally-supported to the attachment base so that it is swingable about the shaft core of the swash plate operating shaft, and the contact member is fixable to the attachment base in any position swingable about the shaft core of the swash plate operating shaft.

Description

  The present invention relates to a swash plate operating device for a hydraulic pump provided in a traveling vehicle such as a vehicle work machine (vehicle construction machine) such as a skid steer loader (SSL) or a compact truck loader (CTL).

Conventionally, a hydrostatic continuously variable transmission that can change the rotation speed and rotation direction of an output shaft by changing the tilt angle of a swash plate of an HST pump comprising a swash plate type variable displacement hydraulic pump by operating a travel lever ( Traveling vehicles with HST) are known.
In a traveling vehicle equipped with this HST, if the swash plate operating device for operating the swash plate of the HST pump is interlocked and connected to the travel lever via a mechanical interlocking mechanism such as a link mechanism, the swash plate of the HST pump The swash plate operating device is equipped with a neutral holding function for holding the swash plate operating shaft in the neutral position. However, there is a variation in the neutral position due to the HST pump. Since the traveling vehicle moves without being operated, a neutral adjustment function is required for the swash plate operating device in order to correct the variation in the neutral position by the HST pump.

As a swash plate operating device having the neutral adjustment function, there is one disclosed in Patent Document 1. The structure described in Patent Document 1 has a complicated structure in order to provide the swash plate operating device with a neutral adjustment function.
Accordingly, there is a swash plate operating device having a neutral adjustment function with a simplified structure, as shown in FIG. In FIG. 8, 50 is a travel lever, 51 is a swash plate operating shaft, 52 is a swash plate operating device, and 53 is a mechanical interlocking mechanism. Moreover, in this FIG. 8, the arrow X direction has shown the front-back direction, the arrow X1 direction has shown the front, and the arrow X2 direction has shown the back. In FIG. 8, the travel lever 50 and its periphery are shown in a side view, and the swash plate operating shaft 51 and the swash plate operating device 52 are shown in a plan view.

The travel lever 50 is supported on a lever support shaft 54 provided on the vehicle body of the traveling vehicle so as to be swingable in the front-rear direction X around the axis in the left-right direction.
The swash plate operating shaft 51 is rotatable about the vertical axis Y, and the tilt angle of the swash plate of the HST pump is changed by rotating left and right around the axis Y.
The swash plate operating device 52 includes a shaft operating member 55 connected to the swash plate operating shaft 51, a pair of left and right cams 56L and 56R provided on the shaft operating member 55, and the pair of cams 56L and 56R. A contact member 57, a mounting base 58 to which the contact member 57 is fixed, and a neutral spring 59 that urges the mounting base 58 so as to press the contact member 57 against the cams 56L and 56R. ing.

The contact member 57 is fixedly attached to the attachment base 58 by a pair of left and right bolts 60, and the bolt insertion hole 61 formed in the attachment base 58 is formed as a long hole in the front-rear direction X and is larger than the diameter of the bolt 60. It is formed wide in the left-right direction.
The mounting base 58 is supported so as to be movable in the front-rear direction X.
The mechanical interlocking mechanism 53 includes a lever arm 63 that swings integrally with the traveling lever 50, a front end side pivotally connected to an upper portion of the lever arm 63, and a rear end side that is on the left and right side portions of the shaft operating member 55 (FIG. 8). In the right side), an interlocking link 64 pivotally connected is provided.

FIG. 8 shows a neutral state. In this neutral position, the contact member 57 is pressed against the cams 56L and 56R by the urging force of the neutral spring 59, and both the pair of cams 56L and 56R are in contact with the contact member 57. By hitting, the swash plate operating shaft 55 is held at the neutral position.
When the travel lever 50 is swung forward from the neutral position to the front X1 to move forward from this neutral state, the interlocking link 64 pulls the right side portion of the shaft operation member 55 forward X1, and the swash plate operation shaft 51 is pivoted. While rotating to one side around the core, the right cam 56R pushes the contact member 57, and the mounting base 58 moves forward X1 against the urging force of the neutral spring 59.

Further, when the traveling lever 50 is swung from the neutral position to the rear X2 in order to move backward, the interlocking link 64 pushes the right side portion of the shaft operation member 55 to the rear X2, and the swash plate operation shaft 51 is rotated around the axis. The left cam 56L pushes the contact member 57 and the mounting base 58 moves forward X1 against the urging force of the neutral spring 59.
When the travel lever 50 is moved back to the neutral position from the position swinging forward X1 or the position swinging backward X2, the mounting base 58 moves backward X2 by the urging force of the neutral spring 59, as shown in FIG. The swash plate operating shaft 51 (swash plate) is held in the neutral position in a state where both the left and right cams 56L and 56R are in contact with the contact member 57.

  Further, when the swash plate operating device 52 is assembled to the HST pump, in order to perform neutral adjustment so that the swash plate operating shaft 51 is held at the neutral position when the traveling lever 50 is not operated, first, the contact member 57 is moved. The bolt 60 fixed to the mounting base 58 is loosened. Next, in this state, the travel lever 50 is operated to make the HST pump neutral (a state in which no pressure oil is discharged). Then, with the HST pump maintained in a neutral state, the contact member 57 is applied so as to contact both the left and right cams 56L and 56R, and the bolt 60 is tightened to attach the contact member 57 to the mounting base 58. Secure to.

US7051641B2

  In the swash plate operating device 52 having the conventional structure shown in FIG. 8, the bolt insertion hole 61 through which the bolt 60 fixing the contact member 57 to the mounting base 58 is formed as a long hole in the front-rear direction X. In addition, since it is formed wider in the left-right direction than the diameter of the bolt 60, when the bolt 60 is loosened, the contact member 57 can move freely in the front-rear, left-right, and diagonal directions. Therefore, when the neutral adjustment is performed, the contact member 57 is attached by tightening the left and right bolts 60 while keeping the contact member 57 in contact with both the left and right cams 56L and 56R. It is difficult to fix to the base 58, and while the bolt 60 is tightened, the contact member 57 is separated from the cams 56L and 56R, and a gap is generated between the contact member 57 and the cams 56L and 56R. For this reason, conventionally, the left and right bolts 60 are tightened so that the contact member 57 can move with respect to the mounting base 58, and the contact member 57 is temporarily fixed to the mounting base 58. 57, the contact member 57 is brought into contact with both the left and right cams 56L, 56R, and then the bolt 60 is finally tightened.

Therefore, the swash plate operating device 52 having the conventional structure has a problem that the neutral adjustment requires too much time, so that the neutral adjustment takes time and the assembly efficiency is poor.
In view of the above problems, an object of the present invention is to provide a swash plate operating device for a hydraulic pump that can easily perform neutral adjustment of the hydraulic pump in a short time.

The technical means taken by the present invention to solve the technical problems are characterized by the following points.
According to the first aspect of the present invention, the shaft operating member is connected to the swash plate operating shaft for operating the swash plate of the swash plate type variable displacement hydraulic pump and operates the swash plate operating shaft about the axis to operate the swash plate. A pair of cams arranged on both sides of the swash plate operation shaft, a contact member that contacts the cam, and a mounting base on which the contact member is fixed And a neutral spring that urges the mounting base so as to press the contact member against the cam, and both the pair of cams contact the contact member at a neutral position of the swash plate operation shaft, When the shaft operating member is rotated about the axis of the swash plate operating shaft, the cam presses the contact member so that the mounting base moves against the urging force of the neutral spring. A swash plate operating device for a pump,
The contact member is supported on the mounting base so as to be swingable about the axis of the swash plate operating shaft, and the contact member is supported at an arbitrary swinging position about the axis of the swash plate operating shaft with respect to the mounting base. It is possible to fix.

  In the invention according to claim 2, a pair of the hydraulic pumps are arranged in parallel in a direction orthogonal to the axis of the swash plate operation shaft, and the shaft operation member and the pair of cams are provided in each of the pair of hydraulic pumps arranged in parallel. , A contact member and a mounting base are provided, and the mounting base on one hydraulic pump side and the mounting base on the other hydraulic pump side are connected so as to be capable of adjusting the relative position in the juxtaposed direction of the hydraulic pumps.

The present invention has the following effects.
According to the first aspect of the present invention, in order to perform neutral adjustment, first, the fixing of the contact member to the mounting base is released, and the contact member can be swung around the axis of the swash plate operating shaft with the mounting base. State. Next, the shaft operating member is operated to rotate the swash plate operating shaft to make the hydraulic pump neutral. At this time, since the contact member is pressed against the cam by the urging force of the neutral spring, the contact member follows the operation of the shaft operation member in a state where the contact member is in contact with both cams.

Therefore, it is not necessary to press the contact member against the cam during neutral adjustment, and after neutralizing the hydraulic pump by operating the shaft operation member, neutral adjustment can be performed simply by fixing the contact member to the mounting base. Adjustment can be done easily in a short time.
According to the second aspect of the present invention, the relative position of the mounting base can be adjusted even if there is a variation in the distance between the swash plate operation shafts in the direction in which the pair of hydraulic pumps are juxtaposed.

It is a side view of a skid steer loader. It is a side view of the swash plate operation system of an HST pump. It is a top view of the swash plate operating device of an HST pump. It is a side view of the swash plate operating device of an HST pump. (A) is a side view of a shaft operation member, (b) is a top view of a shaft operation member. (A) is a side view of a contact member and an attachment base, (b) is a top view of a contact member and an attachment base. It is a top view of the contact member and attachment base which concern on a modification. It is a block diagram of the swash plate operation system of the conventional HST pump.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows a skid steer loader 1 exemplified as a vehicle construction machine.
The skid steer loader 1 includes a body frame 2, a cabin 3 mounted on the body frame 2, a working device 4 mounted on the body frame 2, and traveling devices 5 provided on both left and right sides of the body frame 2. Have

  An engine E is mounted on the rear part of the machine body frame 2, and a pair of HST pumps 7F and 7R for driving driving are arranged in parallel in the front-rear direction X in a pump housing 65 provided on the front side of the engine E. ing. The first to third pumps P1, P2, and P3 are provided in the front-rear direction X at the front X1 of the front HST pump 7F. These HST pumps 7F, 7R and the first to third pumps P1, P2, P3 are driven by the engine E.

The front and rear HST pumps 7F and 7R constitute a part of a hydrostatic continuously variable transmission (HST) that drives the left and right traveling devices 5, and are constituted by swash plate type variable displacement hydraulic pumps.
The HST is provided for each of the left and right traveling devices 5, and by changing the tilt angle of the swash plate of the HST pumps 7F, 7R, the rotation speed and rotation direction of the output shaft of the HST motor can be changed. . The front HST pump 7F drives the left traveling device 5, and the rear HST pump 7R drives the right traveling device 5.

  The first to third pumps P1, P2, and P3 are configured by constant displacement gear pumps, and the first pump P1 drives a hydraulic actuator that is mounted on the work device 4 or a hydraulic actuator that is attached to the work device 4. Is to do. The second pump P2 is used to increase the amount of hydraulic oil, and the third pump P3 is mainly used for supplying control signal pressure.

A driver's seat 8 is provided at the rear of the cabin 3, and a pair of left and right traveling levers 9 </ b> L and 9 </ b> R for operating the traveling device 5 are provided in front of the driver's seat 8. The left traveling lever 9L operates the left traveling device 5 (front HST pump 7F), and the right traveling lever 9R operates the right traveling device 5 (rear HST pump 7R). .
The working device 4 includes left and right booms 10 disposed on both left and right sides of the body frame 2, a bucket 11 provided on the distal end side (front end side) of the left and right booms 10 so as to be swingable up and down, and a base side of the boom 10. The lift link 12 and the control link 13 that support (the rear side), the boom cylinder C1 that drives the boom 10 up and down, and the bucket cylinder C2 that drives the bucket 11 to swing.

The bucket 11 is detachably attached to the front end side (front end side) of the left and right booms 10, and a hydraulic attachment can be attached instead of the bucket 11.
The lift link 12, the control link 13 and the boom cylinder C <b> 1 are provided on the left and right sides of the body frame 2 corresponding to the left and right booms 10. The upper end side of the lift link 12 is pivotally connected to the rear part on the base side of the boom 10, and the lower end side of the lift link 12 is pivotally connected to the upper part on the rear end side of the body frame 2. The control link 13 is disposed in front of the lift link 12, the rear end side thereof is pivotally connected to the lower end portion on the base side of the boom 10, and the front end side thereof is pivotally connected to the body frame 2.

The upper part of the boom cylinder C1 is pivotally connected to the front part on the base side of the boom 10, and the lower part is pivotally connected to the lower part on the rear end side of the body frame 2. By expanding and contracting the boom cylinder C1, the boom 10 is driven to swing so that the base side of the boom 10 is supported by the lift link 12 and the control link 13 so that the tip side of the boom 10 is raised and lowered.
The bucket cylinder C2 is provided on each of the left and right booms 10, and swings and drives the bucket 11 by extending and contracting.

In the present embodiment, the left and right traveling devices 5 are wheel-type traveling devices 5 having front wheels 5F and rear wheels 5R. Note that a crawler type (including a semi-crawler type) traveling device 5 may be employed as the traveling device 5.
As shown in FIG. 2, the left and right traveling levers 9L and 9R are swingable back and forth about the left and right axis on the left and right lever support shaft 14 provided on the body frame 2 on the front side of the HST pumps 7F and 7R. It is supported by. That is, a boss 15 made of a cylindrical body having a horizontal axis is provided at the lower end of each of the left and right traveling levers 9L and 9R, and the traveling levers 9L and 9R are externally fitted to the lever support shaft 14. Is swingable back and forth.

  The front end side 16a of the damper 16 is pivotally connected to the lower part of the left and right traveling levers 9L and 9R, and the rear end side 16b of the damper 16 is pivotally connected to a stay 17 provided on the body frame 2 side. The damper 16 supports the travel levers 9L and 9R, and follows the back-and-forth swing operation of the travel levers 9L and 9R with relatively little resistance when the travel levers 9L and 9R are swung at a relatively slow speed. When the travel levers 9L and 9R are swung at an excessive speed, they become resistance.

A swash plate operating device 18 for operating the swash plates of the HST pumps 7F, 7R is provided above the front and rear HST pumps 7F, 7R. The swash plate operating device 18 and the left and right traveling levers 9L and 9R are interlocked and connected by a mechanical interlocking mechanism 19.
The mechanical interlocking mechanism 19 is provided with a pair of left and right corresponding to the left and right traveling levers 9L, 9R, and is a lever arm that stands on the boss 15 of each traveling lever 9L, 9R and swings integrally with the traveling levers 9L, 9R. 20 and an interlocking link 21 whose front end is pivotally connected to the upper part of the lever arm 20. A joint member 22 is provided at the rear end of the interlocking link 21.

As shown in FIGS. 3 and 4, each of the front and rear HST pumps 7F and 7R is provided with a swash plate operating shaft 23 (trunion shaft) for operating the swash plate so as to protrude upward. The tilt angle of the swash plate of the HST pumps 7F and 7R can be changed by rotating the swash plate operating shaft 23 left and right around the axis. .
The swash plate operating device 18 is provided with a neutral holding function for holding the swash plate operating shaft 23 in a neutral position and a neutral adjustment function for correcting variations in the neutral position of the HST pumps 7F and 7R.

As shown in FIGS. 3 and 4, the swash plate operating device 18 includes a shaft operating member 24 connected to the swash plate operating shaft 23, and a pair of left and right cams 25L and 25R provided on the shaft operating member 24. The contact member 26 with which the cams 25L and 25R abut, the attachment base 27 to which the contact member 26 is attached and fixed, and the attachment base 27 to press the contact member 26 against the cams 25L and 25R. And a neutral spring 28 to be urged.

The shaft operating member 24, a pair of cams 25L and 25R attached to the shaft operating member 24, a contact member 26, and a mounting base 27 are provided for the front and rear HST pumps 7F and 7R, respectively. The front and rear mounting bases 27F and 27R are connected to each other, and the neutral spring 28 is common to the front and rear mounting bases 27F and 27R.
As shown in FIG. 5, the shaft operation member 24 has a rectangular block shape that is long in the left-right direction. A shaft fitting hole 29 is formed in the center portion of the shaft operation member 24 in the front-rear direction X and in the middle in the left-right direction so as to be fitted around the swash plate operation shaft 23 so as not to be relatively rotatable around the axis Y. The operation member 24 can rotate integrally with the swash plate operation shaft 23.

The left and right sides of the shaft operating member 24 are separated into a pair of sandwiching portions 31a and 31b by a groove 30 extending outward in the left-right direction from the shaft fitting hole 29, and pass through the base portions of the pair of sandwiching portions 31a and 31b. The shaft operating member 24 is secured to the swash plate operating shaft 23 by tightening the fixing bolt 32 and the nut 33 screwed onto the fixing bolt 32.
The left and right other sides of the shaft operating member 24 serve as a link connecting portion 34 to which the joint member 22 at the rear end of the interlocking link 21 of the mechanical interlocking mechanism 19 is pivotally connected.

  As shown in FIG. 3, the left side of the front shaft operating member 24 is the link connecting portion 34, and the joint member 22 at the rear end of the interlocking link 21 of the left mechanical interlocking mechanism 19 is pivotally connected. ing. Further, the right side portion of the rear shaft operating member 24 is the link connecting portion 34, and the joint member 22 at the rear end of the interlocking link 21 of the right mechanical interlocking mechanism 19 is pivotally connected. Accordingly, the swash plate of the front HST pump 7F is operated by the left traveling lever 9L, and the swash plate of the rear HST pump 7R is operated by the right traveling lever 9R (the left and right traveling devices 5 are independently operated). Is operable).

  As shown in FIG. 5, the pair of cams 25 </ b> L and 25 </ b> R is configured by a bearing having a vertical axis, and is supported via a cam support shaft 35 fixed to the shaft operation member 24. The pair of cams 25 </ b> L and 25 </ b> R are distributed on the left and right sides of the swash plate operating shaft 23 above the shaft operating member 24. Further, the pair of cams 25L and 25R are provided on the rear side of the shaft operation member 24.

  As shown in FIGS. 3, 4 and 6, the contact member 26 is disposed on the lower surface side of the mounting base 27 and on the front side of the pair of cams 25L and 25R. The contact member 26 has a rectangular block shape that is long in the left-right direction, and a pivotal support portion 36 is provided in the central portion in the left-right direction on the rear side. The pivotal support portion 36 is attached to the mounting base 27 via a pivotal pin 37. The swash plate operating shaft 23 is supported so as to be concentric with the axis Y of the swash plate operating shaft 23.

  The contact member 26 is fixed to the mounting base 27 with mounting bolts 38 on the left and right sides of the pivotal support 36. In the present embodiment, the left and right mounting bolts 38 for mounting and fixing the contact member 26 are screwed into screw holes 40 formed in the contact member 26 through the bolt insertion holes 39 formed in the mounting base 27 from above. Yes. The left and right bolt insertion holes 39 formed in the mounting base 27 are formed in an arc shape centered on the axis Y of the pivot pin 37 (axis Y of the swash plate operating shaft 23). Therefore, by loosening the mounting bolt 38, the contact member 26 can swing left and right around the axis Y of the pivot pin 37 with respect to the mounting base 27.

Further, the contact member 26 is configured such that cams 25L and 25R are in contact with the left and right sides of the rear surface, and both the pair of cams 25L and 25R are in contact with each other at the neutral position of the swash plate operation shaft 23. ing.
As shown in FIGS. 3, 4 and 6, the mounting base 27 is formed of a metal plate material.

The front mounting base 27F has a main wall 27a whose plate surface faces in the up-down direction, and a front wall 27b extending downward from the front end of the main wall 27a. In the mounting base 27F on the front side, the contact member 26 is provided on the front portion of the main wall 27a.
A pair of left and right guide pins 41 are provided on the front wall 27b of the front mounting base 27F so as to protrude forward. The left and right guide pins 41 are supported by a guide portion 43 provided on the support frame 42 so as to be movable in the front-rear direction.

  As shown in FIG. 2, the support frame 42 has a base frame 42A disposed on the lower side of the front and rear HST pumps 7F and 7R, and a vertical frame 42B extending upward from the front end of the base frame 42A. . The base frame 42A is attached and fixed to the engine E and the front HST pump 7F, and a pair of left and right guide portions 43 are provided on the upper surface of the vertical frame 42B.

The rear mounting base 27R has a main wall 27a whose plate surface faces in the vertical direction, and a rear wall 27c extending upward from the rear end of the main wall 27a. In the mounting base 27R on the rear side, the contact member 26 is provided at the rear portion of the main wall 27a.
A cylindrical guide member 44 having an axial center in the front-rear direction is provided at the center in the left-right direction of the rear wall 27c of the rear mounting base 27R. On the front end side of the guide member 44, a spring receiving portion 44a that projects outward in the radial direction is provided.

  A guide shaft 45 is inserted into the guide member 44 from the front, and a screw portion 45 a is formed at the rear portion of the guide shaft 45. The screw portion 45 a is screwed into a support portion 46 provided in the pump housing 65. Are combined. The guide shaft 45 has a neutral spring 28 formed of a compression coil spring interposed between a spring receiving member 47 disposed on the head 45 b side of the guide shaft 45 and a spring receiving portion 44 a of the guide member 44. It is fitted in a compressed form.

Further, the rear portion of the front mounting base 27F and the front portion of the rear mounting base 27R are vertically overlapped, and a pair of left and right connecting bolts 48A penetrating from above the overlapping portions of the front and rear mounting bases 27F and 27R, and the The front and rear mounting bases 27F and 27R are connected to each other by a nut 48B that is screwed to the connecting bolt.
Accordingly, the front and rear mounting bases 27F and 27R are supported by the guide portion 43 and the guide shaft 45 so as to be movable together in the front-rear direction, and are directed rearward by the neutral spring 28 (the contact member 26 is moved toward the cams 25L and 25R). To be pressed against).

Of the bolt insertion holes through which the connecting bolts 48A for connecting the front and rear mounting bases 27F and 27R are inserted, the bolt insertion holes 49 formed in the front mounting base 27F are formed as long holes in the front-rear direction. The front mounting base 27F and the rear mounting base 27R are connected in the front-rear direction (the direction in which the HST pumps 7F and 7R are arranged side by side) so that the relative position can be adjusted.
Thereby, even if the distance between the axes of the swash plate operating shaft 23 in the front-rear direction of the pair of HST pumps 7F, 7R varies, the front-rear relative positions of the front and rear mounting bases 27F, 27R can be adjusted. Relative alignment between the pivot pin 37 that pivotally supports the contact member 26 and the swash plate operating shaft 23 (relative alignment between the contact member 26 and the cams 25L and 25R) can be performed.

  In the swash plate operating device 18 having the above-described configuration, the state shown in FIGS. 3 and 4 is a neutral state, and in this neutral position, the contact member 26 is pressed against the cams 25L and 25R by the urging force of the neutral spring 28. The swash plate operating shaft 23 (swash plate of the HST pumps 7F and 7R) is held in the neutral position by the contact between the pair of cams 25L and 25R with the contact member 26.

  When the traveling levers 9L and 9R are swung forward from the neutral position to advance the skid steer loader 1 from this neutral state, the interlocking link 21 moves the side portion of the shaft operation member 24 forward, and the swash plate operation shaft The cams 25L and 25R on the side close to the joint member 22 at the rear end of the interlocking link 21 push the contact member 26 against the urging force of the neutral spring 28 and move back and forth. The attachment bases 27F and 27R move forward together.

  Further, when the traveling levers 9L and 9R are swung back from the neutral position in order to move backward from the neutral state, the interlocking link 21 pushes the side portion of the shaft operation member 24 rearward, and the swash plate operation shaft 23 is moved. And the cams 25L and 25R on the side farther from the joint member 22 at the rear end of the interlocking link 21 push the contact member 26 to resist the urging force of the neutral spring 28. The mounting bases 27F and 27R move forward together.

Further, when the traveling levers 9L and 9R are returned to the neutral position from the position swinging forward or the position swinging backward, the front and rear mounting bases 27F and 27R are integrally moved backward by the urging force of the neutral spring 28. As shown in FIG. 3, the left and right cams 25 </ b> L and 25 </ b> R return to the neutral state where the left and right cams 25 </ b> L and 25 </ b> R come into contact with the contact member 26 (the swash plate operation shaft 23 returns to the neutral position).
The left and right traveling levers 9L and 9R can be operated independently, and the operation amount of the left and right traveling levers 9L and 9R is set to be larger than the operation amount of the other traveling levers 9L and 9R, or By operating the travel levers 9L, 9R in the reverse direction, the skid steer loader 1 turns.

  In addition, when the swash plate operating device 18 is assembled to the HST pumps 7F and 7R, in order to perform the neutral adjustment so that the swash plate operating shaft 23 is held at the neutral position when the traveling levers 9L and 9R are not operated, In a state where the mounting bolts 38 that fix the contact members 26 to the mounting bases 27F and 27R are loosened, the travel levers 9L and 9R that operate the HST pumps 7F and 7R for neutral adjustment are operated to operate the HST pumps 7F and 7R. To neutral (pressure oil is not discharged). At this time, since the contact member 26 is pressed against the cams 25L and 25R by the urging force of the neutral spring 28, the shaft operating member 24 is swung while the contact member 26 is in contact with both the cams 25L and 25R. The contact member 26 follows the moving operation. Thereafter, with the HST pumps 7F and 7R being neutral, the mounting bolts 38 are tightened to fix the contact member 26 to the mounting bases 27F and 27R.

Accordingly, the horizontal adjustment is unnecessary because the spring force of the neutral spring 28 is directly transmitted to the cams 25L and 25R (there is no need to press the contact member 26 against the cams 25L and 25R during the neutral adjustment). Only the tilt angle is adjusted.
As described above, after operating the swash plate operating shaft 51 by the travel levers 9L and 9R and the shaft operating member 24 to make the HST pumps 7F and 7R neutral, the mounting bolt 38 is tightened to fix the contact member 26 to the mounting base 27F. , 27R, neutral adjustment can be performed only by fixing, and neutral adjustment can be performed easily in a short time reliably.

FIG. 7 shows another embodiment. This other embodiment is different in that the contact member 26 is fixed to the mounting bases 27F and 27R by a single mounting bolt 38 in front of the pivot pin 37. The configuration is the same as in the above embodiment.
In addition, although the said embodiment illustrated the case where this invention was employ | adopted for the skid steer loader 1, you may employ | adopt this invention for vehicle type work machines (traveling vehicles), such as a compact truck loader, a tractor, and a combine.

7F Hydraulic pump (HST pump)
7R Hydraulic pump (HST pump)
23 Swash plate operating shaft 24 Shaft operating member 25L cam 25R cam 26 Contact member 27 Mounting base 28 Neutral spring

Claims (2)

A shaft operating member that is connected to a swash plate operating shaft for operating a swash plate of a swash plate type variable displacement hydraulic pump and that operates the swash plate operating shaft around an axis to operate the swash plate, and provided on the shaft operating member A pair of cams arranged on both sides of the swash plate operating shaft, a contact member that contacts the cam, a mounting base to which the contact member is mounted and fixed, and a cam for the contact member A neutral spring that urges the mounting base so as to be pressed against the cam, and both the pair of cams are in contact with the contact member at a neutral position of the swash plate operation shaft, and the shaft operation member is operated with the swash plate. A swash plate operating device for a hydraulic pump configured to move the mounting base against a biasing force of a neutral spring by pressing a contact member when the cam is rotated around the axis of the shaft. And
The contact member is supported on the mounting base so as to be swingable about the axis of the swash plate operating shaft, and the contact member is supported at an arbitrary swinging position about the axis of the swash plate operating shaft with respect to the mounting base. A hydraulic pump swash plate operating device characterized in that it can be fixed.   A pair of the hydraulic pumps are juxtaposed in a direction perpendicular to the axis of the swash plate operating shaft, and the shaft operating member, a pair of cams, a contact member, and a mounting base are provided for each of the pair of hydraulic pumps arranged side by side. 2. The hydraulic pump according to claim 1, wherein a mounting base on one hydraulic pump side and a mounting base on the other hydraulic pump side are connected so as to be capable of adjusting a relative position in the parallel arrangement direction of the hydraulic pumps. Swash plate operation device.

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