Work vehicles

Abstract

To provide a work vehicle that enables setting a play on a mechanical structure when operating a lever to zero.SOLUTION: A work vehicle 1 according to the present invention comprises: a potentiometer 80 which is disposed on a main body 60, and detects an amount of operation of a lever 58; an adjustment plate 70 to which the lever 58 is attached by being fixed to a shaft member 62; and a torsion spring 64 in which the shaft member 62 is inserted through the center. In states where a first arm part 64A of the torsion spring 64 is in contact with the deepest part 65a of a first groove part 65 of the main body 60, where a second arm part 64B of the torsion spring 64 is in contact with the deepest part 66a of a second groove part 66 of the main body 60, and where a second pushing part 72 of the adjustment plate 70 is in contact with the second arm part 64B, it is configured that a distance between a tip and the first arm part 64A can be adjusted to zero by rotating an adjustment screw 74 of a first pushing part 71 of the adjustment plate 70.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present invention relates to a work vehicle equipped with a hydraulically operated working device. [Background technology]

[0002] As examples of working vehicles, excavators, loaders, etc. have been known which are equipped with a lower body to which tires or crawlers for traveling are attached, an upper body disposed on the lower body, and a working device attached to the lower body or upper body and operated hydraulically. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-139275 A Summary of the Invention [Problem to be solved by the invention]

[0004] The work vehicles exemplified above are equipped with various levers for operating the work equipment, etc. The greater the wobble (so-called "play") in the mechanical structure of the lever, the more the operability deteriorates. Furthermore, the deterioration of operability reduces the sense of luxury of the work vehicle as a whole, and is also a factor that reduces the product value.

[0005] However, conventional operating devices for work vehicles often use a mechanism that opens and closes hydraulic piping for control directly by operating a lever. In other words, multiple hydraulic piping is connected to a main body that supports the lever, which creates a problem that the overall external dimensions of the operating device become large.

[0006] Meanwhile, a mechanism has also been developed that indirectly opens and closes the control hydraulic piping by detecting the amount of lever operation using a potentiometer (angle sensor) or the like and sending a control signal (Patent Document 1: JP 2020-139275 A). This makes it possible to reduce the overall external dimensions of the operating device, since multiple hydraulic piping is not connected to the main body that supports the lever.

[0007] Here, in an operating device equipped with a mechanism for detecting the operation of the above-described lever using a potentiometer, the issues are how to establish the neutral position of the lever and how to reduce rattling (play) in the mechanical structure when operating the lever. [Means for solving the problem]

[0008] The present invention has been made in consideration of the above circumstances, and has an object to provide an operating device in a work vehicle equipped with an operating device that detects lever operation using a potentiometer, which has a simple configuration that enables the establishment of a neutral position of the lever and the return movement of the lever in both directions, and which eliminates any rattling (play) in the mechanical structure when operating the lever.

[0009] The present invention solves the above problems by the means described below.

[0010] A work vehicle according to this embodiment is a work vehicle equipped with a traveling device, a hydraulically operated working device, and an operating device for operating the traveling device or the working device, the operating device having a lever operated by an operator, a potentiometer for detecting the amount of operation of the lever, and a main body for rotatably supporting the lever and to which the potentiometer is fixed, the main body including a shaft member connected to an input portion of the potentiometer and arranged to be rotatable about the same center as the input portion, an adjustment plate fixed to the shaft member and to which the lever is attached, a torsion spring arranged so that the shaft member passes through the center and configured as a first arm portion and a second arm portion having both ends extending outward from the outer periphery, and a torsion spring configured as a torsion spring in an unwinding direction by being twisted in the winding direction. The torsion spring has a first groove and a second groove in which the first arm and the second arm of the torsion spring generate a twisting force and are engaged with each other, and the adjustment plate has a first pushing portion that abuts against and pushes the first arm so as to twist the torsion spring in the winding direction, a second pushing portion that abuts against and pushes the second arm so as to twist the torsion spring in the winding direction, and an adjustment screw that is screwed into the first pushing portion and whose tip portion moves toward and away from the first arm when rotated, and is configured to be adjustable so that the distance between the tip portion and the first arm is zero by rotating the adjustment screw when the first arm is in contact with the innermost portion of the first groove, when the second arm is in contact with the innermost portion of the second groove, and when the second pushing portion is in contact with the second arm.

[0011] According to the above configuration, the neutral position of the lever can be established and the lever can return to its original position in both directions with a simple configuration having a single torsion spring, and any rattling (play) in the mechanical structure can be reduced to zero in both the neutral state and the operating state of the lever.

[0012] It is preferable that the operating device has a stroke adjustment unit that adjusts the stroke range of the lever by adjusting the rotation range of the adjustment plate to which the lever is attached, and the stroke adjustment unit has a first stroke adjustment screw that is screwed into the main body and configured to abut against a first abutment portion of the adjustment plate to restrict the rotation when the adjustment plate is rotated in the direction in which the first pushing portion pushes the first arm portion, and configured so that the distance between the tip end and the first abutment portion of the adjustment plate can be changed by rotation, and a second stroke adjustment screw that is screwed into the main body and configured to abut against a second abutment portion of the adjustment plate to restrict the rotation when the adjustment plate is rotated in the direction in which the second pushing portion pushes the second arm portion, and configured so that the distance between the tip end and the second abutment portion of the adjustment plate can be changed by rotation.

[0013] It is also preferable that the first arm and the first pushing portion are provided at a position on the main body relatively far from the fixed portion of the potentiometer, the second arm and the second pushing portion are provided at a position on the main body relatively close to the fixed portion of the potentiometer, the adjustment screw is screwed into the main body in a direction entering from above to below, the first stroke adjustment screw and the second stroke adjustment screw are screwed into the main body in a direction entering from the front to the rear, and the lever is attached to the adjustment plate at a position forward of the shaft member.

[0014] It is also preferable that the input portion of the potentiometer protrudes toward the main body and has a D-cut surface at its tip, and that the shaft member has an insertion hole into which the tip portion of the input portion is inserted, a screw hole that penetrates from the outer periphery into the insertion hole, and a set screw that is screwed into the screw hole and is capable of abutting against the D-cut surface of the potentiometer. Effect of the Invention

[0015] According to the present invention, in a work vehicle equipped with an operating device that detects the operation of a lever by a potentiometer, it is possible to realize an operating device that can establish the neutral position of the lever and return the lever in both directions with a simple configuration. Furthermore, it is possible to realize an operating device that can eliminate rattling (play) in the mechanical structure in both the neutral state and the operating state of the lever. [Brief description of the drawings]

[0016] [Figure 1] FIG. 1 is a perspective view showing an example of a work vehicle according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a perspective view showing an example of a cockpit of the work vehicle shown in FIG. [Diagram 3] FIG. 3 is an enlarged view of part III in FIG. [Figure 4] FIG. 4 is a perspective view of the operating device for the work vehicle shown in FIG. [Diagram 5] FIG. 5 is a perspective view of the operating device for the work vehicle shown in FIG. [Figure 6] FIG. 6 is a plan view of the operation device of the work vehicle shown in FIG. [Figure 7] FIG. 7 is a cross-sectional view taken along line VII-VII in FIG. [Figure 8] Fig. 8A is a side view of the lever and the adjusting plate rotated in direction A. Fig. 8B is a side view of the lever and the adjusting plate in a neutral state. Fig. 8C is a side view of the lever and the adjusting plate rotated in direction B. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. Fig. 1 is a schematic diagram (perspective view from above the left front) showing an example of a work vehicle 1 according to this embodiment. For convenience of explanation, arrows may be used in the drawings to indicate up / down, left / right, and front / rear directions. In addition, in all drawings for explaining the embodiment, members having the same function are given the same reference numerals, and repeated explanations thereof may be omitted.

[0018] First, an explanation will be given of the overall configuration of the work vehicle 1. An excavator will be taken as an example of the work vehicle 1. However, the work vehicle 1 is not limited to an excavator.

[0019] As shown in Fig. 1, the work vehicle 1 is equipped with a lower body 2 to which a traveling device 10 is attached. The work vehicle 1 is equipped with an upper body 3 which is disposed on the lower body 2 so as to be rotatable via a slewing bearing (not shown). The upper body 3 is driven (rotated) by a slewing hydraulic motor (not shown). The work vehicle 1 is equipped with working devices 12, 13, and 14 which are attached to the lower body 2 and the upper body 3 and which are operated by hydraulic pressure (hydraulic oil at a predetermined pressure).

[0020] The upper body 3 is provided with a cockpit (cabin or canopy) 16 at the front of which is provided with an operating device where an operator rides and operates the vehicle for traveling and work. The upper body 3 is also provided with a control device (not shown) that controls the traveling device 10 and the work devices 12, 13, 14 in response to the operation of the operator. The detailed configuration of the operating device will be described later.

[0021] An example of the traveling device 10 includes four traveling wheels 26, two at the front and two at the back. The traveling wheels 26 have tires 26B fitted onto the outer periphery of wheels 26A (there are both single and double types). However, the traveling device 10 is not limited to the traveling wheels 26. As a modified example, the work vehicle 1 may be configured to include caterpillars (crawlers) instead of the traveling wheels 26 (not shown). The traveling wheels 26 are driven (traveled) by a traveling hydraulic motor (not shown).

[0022] An example of the working device 12 includes a blade 22. The blade 22 is attached to the lower body 2 so as to be swingable up and down (including forward and backward). The blade 22 is driven by a hydraulic cylinder 32. However, the working device 12 is not limited to the above configuration.

[0023] An example of the working device 13 is an outrigger 24. The outrigger 24 is attached to the lower body 2 so as to extend to the left and right and be able to touch the ground. The outrigger 24 is driven by a hydraulic cylinder (not shown). However, the working device 13 is not limited to the above configuration.

[0024] Examples of the working device 14 include a boom 42, an arm 44, and an attachment (a bucket in this embodiment) 46. However, the attachment 46 is not limited to the bucket. The boom 42 is attached to the upper body 3 so as to be swingable up and down (including a front-rear component). In this embodiment, a boom bracket 48 is provided between the upper body 3 and the boom 42. The boom bracket 48 allows the boom 42 to swing left and right (including a front-rear component) with respect to the upper body 3. Note that the boom bracket 48 may be omitted. The arm 44 is attached to the boom 42 so as to be swingable up and down (including a front-rear component). The attachment 46 is attached to the arm 44 so as to be swingable up and down (including a front-rear component). The boom 42 is driven by a hydraulic cylinder 52. The arm 44 is driven by a hydraulic cylinder 54. The attachment 46 is driven by a hydraulic cylinder 56. However, the working device 14 is not limited to the above configuration.

[0025] The mechanism for driving the swing hydraulic motor, traveling hydraulic motor, and each hydraulic cylinder is composed of, for example, a hydraulic pump driven by a drive source 18, a control valve, and the like (none of which are shown). An operator operates the operating device to actuate the control valve, and control is performed to supply hydraulic oil at a predetermined pressure delivered from the hydraulic pump to the swing hydraulic motor, traveling hydraulic motor, and each hydraulic cylinder. This allows the upper body 3 to swing, the traveling device 10 to travel, and the working devices 12, 13, and 14 to perform work.

[0026] In this embodiment, the work vehicle 1 is equipped with an engine as a drive source 18. The drive source 18 is housed in an equipment room 20. However, the drive source 18 is not limited to an engine. As a modified example, the work vehicle 1 may be configured to include a battery-powered electric motor (not shown) instead of or in addition to the engine.

[0027] It should be noted that other mechanisms for travel and work in the work vehicle 1 according to this embodiment are similar to those of known work vehicles (excavators), and therefore detailed description will be omitted.

[0028] Next, the configuration of the operating device provided in the cockpit 16 will be described in detail. Fig. 2 is a perspective view of the cockpit 16 (perspective view from above the left front). The work vehicle 1 is equipped with an operating device 30 for operating the working device 12. The work vehicle 1 is equipped with operating devices 40, 41 for operating the working device 14. However, the operating devices are not limited to the above configuration. As a modified example, the operating device 30 may be configured to be provided with a mechanism for operating the working device 13 (not shown).

[0029] Fig. 3 is an enlarged view of part III in Fig. 2. Fig. 4 is a perspective view of the operating device 30 (perspective view from above the left front part). Fig. 5 is a perspective view of the operating device 30 (perspective view from above the right front part). Fig. 6 is a plan view of the operating device 30 (the upper end part of the lever 58 is not shown). Fig. 7 is a cross-sectional view taken along line VII-VII in Fig. 6. The operating device 30 comprises a main body 60, a lever 58 operated by an operator, and a potentiometer 80 that detects the amount of operation of the lever 58. The lever 58 is rotatably supported by the main body 60. The potentiometer 80 is fixed to the main body 60 (fastened by a mounting screw).

[0030] The main body 60 includes a shaft member 62 that is rotatably provided. The shaft member 62 is connected to an input portion 82 of a potentiometer 80. The main body 60 includes an adjustment plate 70 to which the lever 58 is fixed. The adjustment plate 70 is fixed to the shaft member 62. One example of a method for fixing the lever 58 and the adjustment plate is welding, but the method is not limited to this. One example of a method for fixing the adjustment plate is welding, but the method is not limited to this. The adjustment plate 70 is formed using a plate material having a predetermined thickness, but the method is not limited to this.

[0031] The connection structure between the shaft member 62 and the potentiometer 80 (input section 82) is as follows. The input section 82 of the potentiometer 80 includes an input shaft 84 that protrudes toward the main body 60. The input shaft 84 has a D-cut surface 84b formed at a tip 84a. The shaft member 62 includes an insertion hole 62A into which the tip 84a of the input section 82 (input shaft 84) is inserted. The shaft member 62 includes a screw hole 62B that penetrates from the outer periphery into the insertion hole 62A. The shaft member 62 includes a set screw 94 that is screwed into the screw hole 62B and is provided so as to be able to abut against the D-cut surface 84b of the potentiometer 80 (input shaft 84). According to the above configuration, the set screw 94 is tightened so as to abut against the D-cut surface 84b, whereby the potentiometer 80 (input section 82) and the shaft member 62 can be connected without any rattling (play).

[0032] Next, the main body 60 is provided with a torsion spring (torsion coil spring) 64. The torsion spring 64 is configured as a first arm 64A and a second arm 64B, with both ends 64a, 64b extending outward from the outer periphery (referring to the outer periphery surface position of the coil-shaped portion). The torsion spring 64 is provided on the main body 60 in an arrangement in which the shaft member 62 passes through a center (a space formed at the center of winding) 64C. The torsion spring 64 generates a spring force in the unwinding direction by being twisted in the winding direction.

[0033] The main body 60 has a first groove portion 65 in which the first arm portion 64A of the torsion spring 64 abuts against and engages with the innermost portion 65a when the torsion spring 64 is generating a spring force (a spring force generated in the unwinding direction by being twisted in the winding direction), and a second groove portion 66 in which the second arm portion 64B abuts against and engages with the innermost portion 66a.

[0034] The adjustment plate 70 includes a first pushing portion 71 and a second pushing portion 72 that are perpendicular to the plate surface and extend toward the side where the torsion spring 64 is disposed. The first pushing portion 71 includes an adjustment screw 74, which will be described later.

[0035] Fig. 8 is an explanatory diagram of the operation of the operating device 30. Fig. 8A is a side view of the lever 58 and the adjusting plate 70 rotated in one direction (direction A). Fig. 8B is a side view of the lever 58 and the adjusting plate 70 not rotated (neutral state). Fig. 8C is a side view of the lever 58 and the adjusting plate 70 rotated in the opposite direction (direction B).

[0036] When the lever 58 is operated to rotate the adjusting plate 70 in one direction (direction A) around the shaft member 62, the first pushing portion 71 comes into contact with the first arm 64A and pushes the first arm 64A so as to twist the torsion spring 64 in the winding direction (see FIG. 8A). When the lever 58 is operated to rotate the adjusting plate 70 in the opposite direction (direction B) around the shaft member 62, the second pushing portion 72 comes into contact with the second arm 64B and pushes the second arm 64B so as to twist the torsion spring 64 in the winding direction (see FIG. 8C).

[0037] The adjustment screw 74 is screwed into the first pushing portion 71 to form the first pushing portion 71. When the adjustment screw 74 is rotated, the tip portion moves toward (including abutting against) or away from the first arm portion 64A.

[0038] In the operating device 30, the position of the lever 58 is established as a neutral state when the following states are reached. Specifically, the first arm 64A of the torsion spring 64 is in contact with the innermost portion 65a of the first groove 65 (a state in which a spring force is generated and the lever 58 is in contact). The second arm 64B of the torsion spring 64 is in contact with the innermost portion 66a of the second groove 66 (a state in which a spring force is generated and the lever 58 is in contact). The second pushing portion 72 of the adjustment plate 70 is in contact with the second arm 64B (in this case, the second pushing portion 72 is not pushing the second arm 64B, and the second pushing portion 72 is not being pushed by the second arm 64B). Furthermore, the distance between the tip of the adjustment screw 74 and the first arm 64A is zero (plus or minus zero) (i.e., the adjustment screw 74 is not pushing the first arm 64A, and the adjustment screw 74 is not being pushed by the first arm 64A).

[0039] The operating device 30 can achieve the above state by adjusting (rotating) the adjustment screw 74. In this state, the lever 58 is in a state where there is zero (no) rattle (play) in the mechanical structure with respect to the main body 60. For reference, when the adjustment screw 74 is tightened from this state, the first arm 64A is displaced from the innermost portion 65a, and therefore, when the lever 58 is operated, rattle (play) is generated between the first arm 64A and the innermost portion 65a, or between the second arm 64B and the innermost portion 66a. On the other hand, when the adjustment screw 74 is loosened from this state, the adjustment screw 74 (tip portion) is displaced from the first arm 64A, and therefore, when the lever 58 is operated, rattle (play) is generated between the adjustment screw 74 (tip portion) and the first arm 64A, or between the second pushing portion 72 and the second arm 64B. Incidentally, a double nut is used to prevent the adjustment screw 74 from rotating unintentionally while the work vehicle 1 is in use.

[0040] According to the above configuration, in the operating device 30 having a mechanism for detecting the operation of the lever 58 by the potentiometer 80, a mechanism can be realized that allows the establishment of the neutral position of the lever 58 and the return operation of the lever 58 in both directions, with a simple configuration including one torsion spring 64. Furthermore, the rattle (play) in the mechanical structure when operating the lever 58 can be reduced to zero. Therefore, extremely good operability can be realized. Furthermore, a sense of luxury can be created as a product, and the product value can be further increased.

[0041] Next, the operating device 30 includes a stroke adjustment unit 90 that adjusts the stroke range (operating range) of the lever 58. The stroke adjustment unit 90 adjusts the stroke range of the lever 58 by adjusting the rotation range of the adjustment plate 70 to which the lever 58 is attached.

[0042] The stroke adjustment part 90 includes a first stroke adjustment screw 91 that is screwed into the main body 60. When the first stroke adjustment screw 91 is rotated, the distance between the tip end and the first abutment part 75 of the adjustment plate 70 varies (moves toward or away from the first abutment part 75). The stroke adjustment part 90 includes a second stroke adjustment screw 92 that is screwed into the main body 60. When the second stroke adjustment screw 92 is rotated, the distance between the tip end and the second abutment part 76 of the adjustment plate 70 varies (moves toward or away from the second abutment part 76).

[0043] When the lever 58 is operated to rotate the adjusting plate 70 in one direction (direction A) (the direction in which the first pushing portion 71 pushes the first arm portion 64A) about the shaft member 62, the tip of the first stroke adjustment screw 91 comes into contact with the first abutment portion 75 of the adjusting plate 70, restricting further rotation (see FIG. 8A). When the lever 58 is operated to rotate the adjusting plate 70 in the opposite direction (direction B) (the direction in which the second pushing portion 72 pushes the second arm portion 64B) about the shaft member 62, the tip of the second stroke adjustment screw 92 comes into contact with the second abutment portion 76, restricting further rotation (see FIG. 8C).

[0044] According to the above configuration, the rotation range of the adjustment plate 70 (i.e. the stroke range of the lever 58) can be adjusted by rotating the first stroke adjustment screw 91 and the second stroke adjustment screw 92. Note that double nuts are used to prevent the first stroke adjustment screw 91 and the second stroke adjustment screw 92 from rotating unintentionally while the work vehicle 1 is in use.

[0045] In particular, it is possible to realize a structure in which one adjustment plate 70 is used for both rattle (play) adjustment and stroke adjustment when operating the lever 58. Therefore, it is possible to realize an operating device 30 with a simple structure.

[0046] Next, the arrangement of each component of the operating device 30 will be described. As shown in Fig. 6, the first arm 64A and the first pushing portion 71 (specifically, the abutment position with the first arm 64A) are provided in a position on the main body 60 that is relatively far from the fixed portion 60A of the potentiometer 80. The second arm 64B and the second pushing portion 72 (specifically, the abutment position with the second arm 64B) are provided in a position on the main body 60 that is relatively close to the fixed portion 60A of the potentiometer 80. The adjustment screw 74 is screwed in a direction that advances from the top to the bottom of the main body 60. The first stroke adjustment screw 91 and the second stroke adjustment screw 92 are screwed in a direction that advances from the front to the rear of the main body 60. The lever 58 is attached to the adjustment plate 70 at a position forward of the shaft member 62.

[0047] According to the above configuration, in the operation device 30 that enables the lever 58 to be brought to a neutral position and returned to its original position by a single torsion spring 64, it is possible to reduce (thin) the width dimension in the direction perpendicular to the operation direction (direction A and direction B) of the lever 58. Furthermore, with the operation device 30 mounted (fixed) on the work vehicle 1, it is possible to easily adjust (rotate using a tool) all of the adjustment screw 74, the first stroke adjustment screw 91, and the second stroke adjustment screw 92.

[0048] This embodiment has been described by taking the operation device 30 of the working device 12 as an example. Note that this embodiment is not limited to the operation device 30, and can be similarly applied to operation devices of other devices (for example, the traveling device 10, the working device 13, the working device 14, etc.).

[0049] Next, the switches provided in the cockpit 16 are configured as follows. As shown in Fig. 3, from the front, a driving switch 110, an operation switch with a jog dial 120, a common switch 130, a key switch 140, and an optional mechanism switch 150 are all arranged together in one console box 100. Furthermore, the wiring for the above switches is gathered into one connector (not shown) and is connected to a main body side connector (not shown). As an example, the console box 100 is formed by integral molding using a resin material.

[0050] Examples of the driving system switches 110 include switches for the parking brake, foot accelerator, ram lock (lock / auto), hazard, attachment lock, driving shift, and auto cruise. Examples of the operation switch 120 with jog dial include a jog dial 122, and switches for the air conditioner, radio, and display. Examples of the common switch 130 include switches for the sidelights, headlights, work lights, gear shift, beacon, eco mode, detent, swing / adjust switch, and differential lock. Examples of the option mechanism switch 150 include switches for four-wheel steering switch and other spare switches. However, the switches are not limited to the above configuration.

[0051] According to the above configuration, the number of parts can be reduced, and the structure can be simplified, costs can be reduced, assembly can be simplified, and the number of steps can be reduced.

[0052] The arrangement of the console box 100 and the above-mentioned switches will be described. The console box 100 is disposed in a position sandwiched between the operation device 30 and the operation device 40. Furthermore, the travel-related switch 110 is disposed on the front side close to the lever 58, and the operation switch 120 with a jog dial is disposed on the rear side close to the lever 58. This allows the operator to operate the frequently used travel-related switch 110, the operation switch 120 with a jog dial, the operation device 30, and the operation device 40 without changing (making a large change) his or her line of sight, thereby realizing good operability.

[0053] As described above, according to the above-mentioned work vehicle, when the operating device detects the operation of the lever by a potentiometer, it is possible to realize an operating device with a simple configuration that allows the establishment of the neutral position of the lever and the return movement of the lever in both directions. Furthermore, it is possible to realize an operating device that can reduce rattling (play) in the mechanical structure to zero in both the neutral state and the operating state of the lever.

[0054] According to the above-described work vehicle, it is possible to reduce the number of parts, thereby reducing costs and simplifying the assembly process.

[0055] The present invention is not limited to the above embodiment (excavator), and can be similarly applied to other work vehicles (for example, loaders, carriers, etc.). [Explanation of symbols]

[0056] 1. Work vehicles 10 Running gear 12, 13, 14 Work equipment 16 Cockpit 30 Operating device 58 Lever 60 Main Unit 62 Shaft member 64 Torsion Spring 64A 1st arm 64B 2nd arm 65 First Groove 66 Second Groove 70 Adjustment Plate 71 First pushing part 72 Second pushing part 74 Adjustment screw 80 Potentiometer 90 Stroke adjustment part

Claims

1. A work vehicle including a traveling device, a hydraulically operated working device, and an operating device for operating the traveling device or the working device, The operating device is A lever operated by an operator; a potentiometer for detecting an amount of operation of the lever; a main body to which the lever is rotatably supported and to which the potentiometer is fixed, The body includes: a shaft member connected to an input portion of the potentiometer and rotatably provided coaxially with the input portion; an adjustment plate fixed to the shaft member and to which the lever is attached; a torsion spring configured as a first arm portion and a second arm portion, the first arm portion and the second arm portion each extending outward from an outer periphery of the torsion spring, the first arm portion and the second arm portion being disposed so that the shaft member passes through the center of the torsion spring; a first groove portion and a second groove portion in which the first arm portion and the second arm portion of the torsion spring abut and are locked at their innermost portions when the torsion spring is twisted in the winding direction to generate a spring force in the unwinding direction, The adjustment plate is a first pushing portion that comes into contact with the first arm portion and pushes the torsion spring in a winding direction; a second pushing portion that comes into contact with the second arm portion and pushes the torsion spring in a winding direction; an adjustment screw that is screwed into the first pushing portion and whose tip portion moves toward and away from the first arm portion when rotated; The distance between the tip portion and the first arm portion can be adjusted to zero by rotating the adjustment screw when the first arm portion is in contact with the innermost portion of the first groove portion, the second arm portion is in contact with the innermost portion of the second groove portion, and the second pushing portion is in contact with the second arm portion. A work vehicle characterized by:

2. the operating device has a stroke adjustment unit that adjusts a stroke range of the lever by adjusting a rotation range of the adjustment plate to which the lever is attached, The stroke adjustment unit is a first stroke adjustment screw that is screwed into the main body and configured to restrict rotation by contacting a first contact portion of the adjustment plate when the adjustment plate is rotated in a direction in which the first pushing portion pushes the first arm portion, and that is configured so that a distance between a tip portion and the first contact portion of the adjustment plate can be changed by rotation; a second stroke adjustment screw configured to be screwed into the main body and to come into contact with the second abutment portion of the adjustment plate to restrict the rotation when the adjustment plate is rotated in a direction in which the second pushing portion pushes the second arm portion, and configured to vary the distance between the tip portion and the second abutment portion of the adjustment plate by rotation; 2. The work vehicle according to claim 1,

3. the first arm portion and the first pushing portion are provided in a position on the main body that is relatively far from a fixed portion of the potentiometer, the second arm portion and the second pushing portion are provided in the main body at a position relatively close to the fixed portion of the potentiometer, The adjustment screw is screwed into the main body in a direction from above to below, the first stroke adjustment screw and the second stroke adjustment screw are screwed into the main body in a direction from the front to the rear, The lever is attached to the adjustment plate at a position forward of the shaft member.

3. The work vehicle according to claim 2,

4. The input portion of the potentiometer is provided to protrude toward the main body and has a D-cut surface at a tip portion, the shaft member has an insertion hole into which the tip end of the input portion is inserted, a screw hole penetrating from an outer periphery into the insertion hole, and a set screw screwed into the screw hole and provided so as to be able to abut against the D-cut surface of the potentiometer; 4. The work vehicle according to claim 2 or 3, characterized in that

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