Agricultural vehicles

Abstract

To perform regulation and fixation of a driving speed with a simple configuration.SOLUTION: A farm work vehicle includes: a gear change pedal 37 (an example of an operation tool) that is used in operation of adjusting a driving speed of at least one of a travel body and a work machine; a regulation member 70 that regulates an operation amount of the gear change pedal 37 by contacting with the gear change pedal 37 within a movable range of the gear change pedal 37; and engagement means 80 that fixes the gear change pedal 37 to a predetermined operation amount by engaging the gear change pedal 37 and the regulation member 70.SELECTED DRAWING: Figure 5

Description

Technical Field

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[0001] The present invention relates to an agricultural work vehicle.

Background Art

[0006] Considering the above circumstances, the present invention aims to provide an agricultural vehicle that can limit and fix the drive speed with a simple configuration. [Means for solving the problem]

[0007] To solve the above problems, the agricultural vehicle according to the present invention comprises: an operating tool used for adjusting the driving speed of at least one of the vehicle body and the work machine; a limiting member that limits the amount of operation of the operating tool by contacting the operating tool within the movable range of the operating tool; and an engaging means that fixes the operating tool at a predetermined amount of operation by engaging the operating tool and the limiting member.

[0008] The predetermined amount of operation may be less than or equal to the amount of operation limited by the limiting member.

[0009] The agricultural vehicle is equipped with a support body that supports the operating tool and the limiting member, and the limiting member may be movable between a limiting position that limits the amount of operation of the operating tool by contacting the operating tool within the movable range, and a retracted position that does not contact the operating tool.

[0010] The agricultural vehicle is equipped with a tension spring, one end of which is connected to the support and the other end of which is connected to the limiting member, the limiting member being pivotable between the limiting position and the retracted position about a first axis, the neutral position being the most extended position of the tension spring when the center line of the tension spring coincides with the first axis as viewed from the axial direction of the first axis, the limiting position and the retracted position being located in opposite directions with the neutral position in between, and the tension spring may bias the limiting member toward either the limiting position side or the retracted position side.

[0011] The operating tool is pivotable about a second axis parallel to the first axis and is biased in a direction that reduces the amount of operation. When the operating tool and the limiting member are engaged by the engaging means, the limiting member is biased toward the limiting position by the tension spring. The engagement by the engaging means may be released when the operating tool is operated toward the limiting position from a state in which the operating tool and the limiting member are engaged by the engaging means. [Effects of the Invention]

[0012] According to the present invention, the drive speed can be limited and fixed with a simple configuration. [Brief explanation of the drawing]

[0013] [Figure 1] This is a left side view showing an agricultural vehicle according to one embodiment of the present invention. [Figure 2] This is a plan view showing an agricultural vehicle according to one embodiment of the present invention. [Figure 3] This is a plan view showing the power transmission mechanism of an agricultural vehicle according to one embodiment of the present invention. [Figure 4] This is a plan view showing a gear shift mechanism and a brake mechanism according to one embodiment of the present invention. [Figure 5] This is a perspective view showing a gear shift pedal according to one embodiment of the present invention. [Figure 6] This is a right side view showing a gear shift pedal according to one embodiment of the present invention. [Figure 7]It is a right side view showing a shift pedal according to an embodiment of the present invention. [Figure 8] It is a left side view showing a state where a restricting member according to an embodiment of the present invention is in a retracted position. [Figure 9] It is a left side view showing a state where a restricting member according to an embodiment of the present invention is in a neutral position. [Figure 10] It is a left side view showing a state where a restricting member according to an embodiment of the present invention is in an engaged position. [Figure 11] It is a left side view showing a state where a restricting member according to an embodiment of the present invention is in a restricted position.

Mode for Carrying Out the Invention

[0014] Hereinafter, an agricultural work vehicle 1 according to an embodiment of the present invention will be described while referring to the drawings.

[0015] First, the overall configuration of the agricultural work vehicle 1 will be described. FIG. 1 is a left side view showing the agricultural work vehicle 1. FIG. 2 is a plan view showing the agricultural work vehicle 1. FIG. 3 is a plan view showing the power transmission mechanism 20 of the agricultural work vehicle 1. In each figure, U, Lo, L, R, Fr, and Rr indicate up, down, left, right, front, and rear, respectively.

[0016] The agricultural work vehicle 1 (see FIGS. 1 to 3) includes a traveling body 2 and a working machine 3 provided behind the traveling body 2. For example, the working machine 3 is a planting device that performs the planting work of rice seedlings, and the agricultural work vehicle 1 is a rice transplanter that performs the planting work of seedlings by the working machine 3 while traveling by the traveling body 2. Note that the working machine 3 may be a device that performs transplanting, sowing, tilling, etc. of vegetables and grains.

[0017] The traveling body 2 includes a vehicle body frame 10, a drive source 11 and a transmission 12 provided at the center in the left - right direction at the front of the vehicle body frame 10, a pair of left and right front wheels 13 provided at the front of the vehicle body frame 10, and a pair of left and right rear wheels 14 provided at the rear of the vehicle body frame 10.

[0018] The drive source 11 generates driving force to drive the front wheels 13 and the rear wheels 14. The drive source 11 is, for example, an internal combustion engine that uses diesel fuel and is covered by a bonnet 21. The transmission 12 (see Figure 3) is located behind the drive source 11 and shifts the driving force generated by the drive source 11. Front axles 19 are provided on the left and right sides of the transmission 12. The front wheels 13 are attached to the front axle 19S provided on the front axle 19 and are driven by the driving force transmitted from the transmission 12.

[0019] The rear axle 24 is located behind the transmission 12 and is connected to the transmission 12 by a joint member 23 whose longitudinal direction is in the front-rear direction. The rear wheel drive shaft 25 is located along the joint member 23 and transmits driving force from the transmission 12 to the rear axle 24. The rear wheels 14 are attached to the rear axle 24S located on the rear axle 24 and are driven by the driving force transmitted via the rear wheel drive shaft 25. Note that crawlers (not shown) may be provided instead of the rear wheels 14.

[0020] The driver's seat 15 is located above the joint member 23. The driver's seat 15 is surrounded by a steering wheel 16, a gear lever (not shown), a gear pedal 37 (an example of an operating device), a brake pedal 38, etc. The front wheels 13 steer the vehicle 2 in conjunction with the operation of the steering wheel 16. The steps 17 (see Figure 2) are flat members that serve as a platform for the worker and are located around the driver's seat 15 and on the left and right sides of the bonnet 21. The spare seedling trays 18 are located on the left and right sides of the bonnet 21 and are on which seedling mats to be replenished in the work machine 3 are placed.

[0021] The inter-row gear changer 27 (see Figure 3) is located above the rear axle 24, slightly to the right of the center in the left-right direction. The inter-row gear changer 27 changes the driving force input from the transmission 12 via the drive shaft 35A and outputs it to the implement 3 via the drive shaft 35B.

[0022] The working machine 3 comprises a seedling tray 30 on which seedling mats are placed, and a main frame 31. The main frame 31 is a rod-shaped member with its longitudinal direction running horizontally, and has a center case 33 in the center in the horizontal direction. Planting transmission cases 34 are provided at approximately equal intervals at multiple locations (four locations in this example) in the horizontal direction behind the main frame 31. The planting transmission cases 34 are provided with a pair of transplanting mechanisms 32 on the left and right sides.

[0023] The drive shaft 35B is connected to the input shaft 33A of the center case 33 via a universal joint. The center case 33 is equipped with a gear train (not shown) including bevel gears. The output shaft 33B of the center case 33 is mounted along the main frame 31 and connected to each planting transmission case 34. The driving force is transmitted to the transplanting mechanism 32 via the drive shaft 35B, the center case 33, and the planting transmission cases 34. The implement 3 is equipped with a lateral drive unit (not shown) that drives the seedling tray 30 to move laterally in the left-right direction. As the seedling tray 30 reciprocates from left to right, the transplanting mechanism 32 takes seedlings from the seedling tray 30 and plants them in the field.

[0024] The work machine 3 is equipped with a lifting device 22. The lifting device 22 comprises a columnar frame 10P, a pair of parallel upper and lower link members 22L, and a hydraulic cylinder 22C. The vehicle frame 10 is supported by the columnar frame 10P, which is provided above the rear axle 24. The columnar frame 10P and the seedling tray 30 are connected by a pair of link members 22L. The nodes of the columnar frame 10P, the seedling tray 30, and the pair of link members 22L form the four vertices of a parallelogram. The hydraulic cylinder 22C is connected to a joint member 23 and the lower link member 22L. The extension and retraction of the hydraulic cylinder 22C causes the pair of link members 22L to swing with the nodes on the columnar frame 10P side as pivot points, thereby raising and lowering the seedling tray 30.

[0025] Figure 4 is a plan view showing the gear shift mechanism 4 and the brake mechanism 5. Figure 5 is a perspective view showing the gear shift pedal 37. Figures 6 and 7 are right side views showing the gear shift pedal 37. The gear shift mechanism 4 and the brake mechanism 5 are supported by a support 40. The support 40 is mainly formed by combining tubular members whose longitudinal direction is in the front-rear or left-right direction. The gear shift pedal 37 (an example of an operating device) and the brake pedal 38 are located to the right front of the driver's seat 15. The brake pedal 38 is located to the left of the gear shift pedal 37.

[0026] [Transmission mechanism] The transmission mechanism 4 (see Figure 4) comprises an HST41 (Hydraulic Static Transmission), a planetary gear mechanism (not shown), a stepped transmission (not shown), and a gear shift pedal 37. The HST41, planetary gear mechanism, and stepped transmission are located below the support 40. The HST41 includes a hydraulic pump 41P and a hydraulic motor 41M. The driving force generated by the drive source 11 is transmitted to the hydraulic pump 41P and the planetary carrier provided in the planetary gear mechanism. The hydraulic motor 41M is driven by the discharge of hydraulic fluid from the hydraulic pump 41P to the hydraulic motor 41M. The amount of hydraulic fluid discharged is adjusted by changing the angle of the swash plate (not shown) of the hydraulic pump 41P. The angle of the swash plate is adjusted by rotating the trunnion shaft 41T using the gear shift pedal 37. The hydraulic motor 41M drives the sun gear provided in the planetary gear mechanism.

[0027] When the gear shift pedal 37 is not pressed (maximum position), the swash plate is at its most tilted position, and the hydraulic motor 41M rotates at its highest speed. In this case, the rotation of the planetary gear and sun gear cancels each other out, causing the ring gear to stop. As the amount of pressure applied to the gear shift pedal 37 (an example of the amount of operation of the control tool) increases relative to the maximum position, the tilt angle of the swash plate decreases, and the rotation speed of the hydraulic motor 41M and sun gear decreases, causing the rotation speed of the ring gear to increase.

[0028] A stepped transmission comprises an input shaft, an output shaft, and a gear train that transmits driving force from the input shaft to the output shaft. The rotation of the ring gear is transmitted to the input shaft, and the driving force is changed by changing the gear ratio of the gear train in response to the operation of the shift lever.

[0029] The gear shift pedal 37 (see Figures 4 to 7) is attached to a gear shift pedal support member 37S provided on a support body 40. The rear end of the gear shift pedal 37 is hinged to the gear shift pedal support member 37S via a second shaft 372 whose axial direction is in the left-right direction, and the gear shift pedal 37 is pivotable about the second shaft 372. The gear shift pedal 37 is operated within a predetermined range of motion that is inclined so that the front side is higher than the rear side.

[0030] An arm 42 (see Figures 6 and 7) is provided in front of the gear shift pedal 37, with its longitudinal direction in the front-rear direction. The front end of the arm 42 is supported by a support body 40 via an arm axis 42S with its axial direction in the left-right direction, and the arm 42 is pivotable about the arm axis 42S. A boss 40B protruding to the right is provided on the support body 40 in front of the arm axis 42S. Additionally, a boss 42B protruding to the right is provided at the rear end of the arm 42. A tension spring 42T is connected to the two bosses 40B and 42B. The tension spring 42T is a tension coil spring.

[0031] A downward-projecting protrusion 37T is provided in front of the center of the lower surface of the gear shift pedal 37. The gear shift rod 43 is pivotably connected to the protrusion 37T and the rear end of the arm 42.

[0032] When the gear shift pedal 37 is in its highest position (see Figure 6), the center line 42C of the tension spring 42T, viewed from the right, coincides with the arm axis 42S, so the tension spring 42T is in its most extended state, and the tensile force P is at its maximum value Pmax. As the gear shift pedal 37 is pressed down (see Figure 7), the tension spring 42T compresses, and the tensile force P decreases. The pedaling force N acts in a direction perpendicular to the upper surface of the gear shift pedal 37. If the angle between the direction of the pedaling force N and the longitudinal direction of the gear shift rod 43 is θ, then the component force Ncosθ of the pedaling force N in the longitudinal direction of the gear shift rod 43 acts on the rear end of the arm 42. As a result, the resultant force of the tensile force P and the component force Ncosθ acts on the rear end of the arm 42. In other words, the tension spring 42T has the function of assisting the pressing of the gear shift pedal 37.

[0033] The front end of a gear shift rod 44 (see Figures 4, 6, and 7), whose longitudinal direction is in the front-to-back direction, is pivotably connected to the lower front of the arm 42. An L-shaped pivot 45 (see Figure 4) is provided behind the gear shift pedal 37. The pivot 45 is supported by a bracket 40A provided on the support body 40 via an axis 45S whose axial direction is in the up-to-down direction, and is pivotable about the axis 45S. The rear end of the gear shift rod 44 is pivotably connected to one end of the pivot 45. The right end of a gear shift rod 46, whose longitudinal direction is in the left-to-right direction, is pivotably connected to the other end of the pivot 45.

[0034] The trunnion shaft 41T (see Figure 4) is oriented axially in the vertical direction. An operating arm 41A is provided on the trunnion shaft 41T. The operating arm 41A includes a projection 41B that protrudes behind the trunnion shaft 41T and a projection 41C that protrudes to the right of the trunnion shaft 41T. The left end of the speed change rod 44 is pivotably connected to the projection 41B.

[0035] One end of a return spring 47 is connected to the protruding portion 41C. The other end of the return spring 47 is connected to a support 40 located to the left rear of the protruding portion 41C. The return spring 47 is a tension coil spring and biases the operating arm 41A in a clockwise direction in Figure 4. When the operating arm 41A swings clockwise, the gear shift rod 46 is pulled to the left, causing the pivot 45 to swing clockwise and the gear shift rod 44 to be pulled rearward. As a result, the arm 42 swings clockwise in Figure 7 (see Figure 6), and the gear shift pedal 37 is pushed up via the gear shift rod 43 (see Figure 6). In other words, the return spring 47 biases the gear shift pedal 37 in a direction that reduces the amount it is pressed (upward).

[0036] When the gear shift pedal 37 is pressed down, the arm 42 swings counterclockwise in Figure 6 via the gear shift rod 43 (see Figure 7), pulling the gear shift rod 44 forward. As a result, the pivot 45 swings counterclockwise in Figure 4, pulling the gear shift rod 46 to the right, causing the operating arm 41A to swing counterclockwise in Figure 4, and the trunnion shaft 41T to be operated counterclockwise. When the force applied to the gear shift pedal 37 is reduced, the operating arm 41A swings clockwise due to the return spring 47, pushing up the gear shift pedal 37 as described above.

[0037] [Brake mechanism] A brake (not shown) is provided on the output shaft of the stepped transmission. The brake has a brake shaft 51 (see Figure 4) whose axis is oriented vertically, and is operated by rotating the brake shaft 51 using the brake pedal 38.

[0038] The brake pedal 38 is connected to the support body 40 via a brake pedal shaft 38S whose axis is oriented in the left-right direction, and is pivotable about the brake pedal shaft 38S. The brake pedal 38 is biased in a direction that reduces the amount of depression by a torsion coil spring 38T wrapped around the brake pedal shaft 38S. A brake rod 52 whose longitudinal direction is oriented in the front-rear direction is pivotably connected to the brake pedal 38 at a point above the brake pedal shaft 38S.

[0039] The brake shaft 51 is biased clockwise in Figure 4. A brake arm 53 is provided on the brake shaft 51. The tip of the brake arm 53 protrudes to the right from the brake shaft 51. A contact portion 52C is provided on the brake rod 52. The contact portion 52C is located behind the tip of the brake arm 53. A brake rod support member 54 is provided on the brake shaft 51 to support the brake rod 52 so that it can slide in the front-rear direction. A leaf spring 55 protruding to the right is provided on the brake rod support member 54. The leaf spring 55 is capable of bending in the front-rear direction.

[0040] When the brake pedal 38 is pressed, the brake rod 52 is pulled forward, causing the contact portion 52C to swing the brake arm 53 counterclockwise in Figure 4, which in turn causes the brake shaft 51 to rotate counterclockwise, thereby activating the brake.

[0041] If the hydraulic fluid temperature rises, the hydraulic pressure inside the HST41 may rise even if the gear shift pedal 37 is not pressed, potentially transmitting driving force to the front wheels 13, rear wheels 14, and work implement 3. To prevent this phenomenon, a configuration is provided that causes the brake shaft 51 to rotate slightly to counteract the driving force of the output shaft of the stepped transmission when the gear shift pedal 37 is not pressed.

[0042] Specifically, a pivot 56 is provided to the right of the operating arm 41A. The pivot 56 is supported by the support body 40 via an axis 56S whose axis is oriented vertically, and is pivotable about the axis 56S. The left end of the pivot 56 is pivotably connected to a protruding portion 41C of the operating arm 41A.

[0043] An arm 57 is provided to the right rear of the pivot 56 and to the left of the brake shaft 51. The arm 57 is supported by the support 40 via an axis 57S whose axis is oriented vertically, and is pivotable about the axis 57S. A rod 58 is pivotably connected to the left end of the arm 57 and the right end of the pivot 56. A pressing member 59 is provided at the right end of the arm 57. The pressing member 59 is positioned in front of the left end of the leaf spring 55.

[0044] When the operating arm 41A swings clockwise in Figure 4 due to the return spring 47, the pivot 56 swings counterclockwise, which pulls the rod 58 forward and causes the arm 57 to swing clockwise. As a result, the pressing member 59 presses the leaf spring 55 backward, causing the brake shaft 51 to swing counterclockwise, and thus the brake is activated.

[0045] Next, the limiting member 70 and the engaging means 80 will be described (see Figures 5 to 11). Figure 8 is a left side view showing the limiting member 70 in the retracted position. Figure 9 is a left side view showing the limiting member 70 in the neutral position. Figure 10 is a left side view showing the limiting member 70 in the engaging position. Figure 11 is a left side view showing the limiting member 70 in the limiting position.

[0046] The agricultural vehicle 1 according to this embodiment includes a gear shift pedal 37 (an example of an operating tool) used to adjust the driving speed of at least one of the vehicle body 2 and the work implement 3, a limiting member 70 that limits the amount of operation of the gear shift pedal 37 by contacting the gear shift pedal 37 within the range of motion of the gear shift pedal 37, and an engaging means 80 that fixes the gear shift pedal 37 to a predetermined amount of operation by engaging the gear shift pedal 37 with the limiting member 70. Specifically, it is as follows. As the gear shift pedal 37 has been described above, the following will mainly describe the limiting member 70 and the engaging means 80.

[0047] [Restricting member] The pedal receiving member 71 is positioned in front of the gear shift pedal support member 37S and is attached to the upper surface of the support body 40. The upper end of the pedal receiving member 71 is provided with a first contact portion 711 that contacts the lower surface of the pressed gear shift pedal 37. When the lower surface of the gear shift pedal 37 contacts the first contact portion 711, the gear shift pedal 37 cannot be pressed any further. In other words, the amount of pressure applied when the lower surface of the gear shift pedal 37 contacts the first contact portion 711 is the maximum amount of pressure applied to the gear shift pedal 37.

[0048] The limiting member 70 is an elongated plate-shaped member. The limiting member 70 comprises a base portion 70A, which is one end in the longitudinal direction, a tip portion 70C, which is the other end in the longitudinal direction, and an intermediate portion 70B that connects the base portion 70A and the tip portion 70C. As shown in Figure 9, when viewed from the left, the intermediate portion 70B is bent counterclockwise with respect to the base portion 70A, and the tip portion 70C is bent counterclockwise with respect to the intermediate portion 70B. The angle between the base portion 70A and the tip portion 70C is approximately 90°. The base portion 70A is hinged to the rear of the pedal receiving member 71 via a first shaft 701. The first shaft 701 is located slightly higher than the upper surface of the support 40.

[0049] The limiting member 70 is pivotable around the first axis 701 between a retracted position (see Figure 8) and a limiting position (see Figure 11). In the retracted position, the area near the connection point between the base portion 70A and the intermediate portion 70B contacts the upper surface of the support 40. The pedal receiving member 71 has a second contact portion 712 located behind the first contact portion 711 and lower than the first contact portion 711. In the limiting position, the tip portion 70C contacts the second contact portion 712. A boss 71B protruding to the left is provided on the pedal receiving member 71 at a point diagonally forward and downward from the first axis 701. Additionally, a boss 70BB protruding to the left is provided on the intermediate portion 70B. A tension spring 70T is connected to the two bosses 71B and 70BB. The tension spring 70T is a tension coil spring.

[0050] In the neutral position (see Figure 9), the limiting member 70 is positioned such that the center line 70TC of the tension spring 70T, viewed from the axial direction of the first shaft 701, coincides with the first shaft 701, and the tension spring 70T is in its most extended state. The limiting position (see Figure 11) and the retracted position (see Figure 8) are located in opposite directions with the neutral position in between. The tension spring 70T biases the limiting member 70 towards either the limiting position or the retracted position. For example, if an external force acts to swing the limiting member 70 towards the retracted position in the neutral position, the tension spring 70T pulls the limiting member 70 into the retracted position. Conversely, if an external force acts to swing the limiting member 70 towards the limiting position in the neutral position, the tension spring 70T pulls the limiting member 70 into the limiting position.

[0051] The tip portion 70C of the limiting member 70 is provided with a protruding member 72 that protrudes in a clockwise direction when viewed from the left. The tip portion 70C is provided with a hole (not shown) that penetrates in the thickness direction. The protruding member 72 comprises a support portion 72A that is inserted into the hole, and a third contact portion 723 provided at the tip of the support portion 72A with the left-right direction as its longitudinal direction. The third contact portion 723 has a length equal to the left-right width of the gear shift pedal 37 and has equal length on both the left and right sides of the support portion 72A. With this configuration, the left-right width of the contact point between the gear shift pedal 37 and the third contact portion 723 is equal on both the left and right sides of the support portion 72A, thereby suppressing the left-right tilting of the gear shift pedal 37. At the limiting position, the lower surface of the gear shift pedal 37 contacts the third contact portion 723, thereby limiting the amount the gear shift pedal 37 is pressed to less than the maximum pressing amount.

[0052] The support column 72A is provided with a screw thread. The support column 72A is fixed to the tip portion 70C by tightening nuts from both the gear shift pedal 37 side and the pedal receiving member 71 side. By shifting the position of the nuts in the axial direction relative to the support column 72A, the amount of protrusion of the protruding member 72 is adjusted, and thus the amount of restriction on the pedaling amount by the limiting member 70 is adjusted.

[0053] [Engaging means] A hook 37F is provided on the protruding portion 37T of the gear shift pedal 37, which protrudes downward. When the hook 37F is engaged with the third contact portion 723 at the engagement position between the restricted position and the retracted position (see Figure 10), the force of the return spring 47 that returns the gear shift pedal 37 and the force of the tension spring 70T that biases the gear shift pedal 37 downward balance each other, fixing the amount the gear shift pedal 37 is pressed down. The hook 37F and the third contact portion 723 are examples of the engagement means 80.

[0054] Next, the operation of the above configuration will be described. When there is no need to limit the amount the gear shift pedal 37 is pressed, the driver moves the limiting member 70 to the retracted position (see Figure 8). The limiting member 70 is moved with the hands or toes. In this case, the gear shift pedal 37 can be pressed within the range until the lower surface of the gear shift pedal 37 contacts the first contact portion 711 of the pedal receiving member 71.

[0055] When it is necessary to limit the amount the gear shift pedal 37 is pressed, such as when planting at a slower speed than usual, the driver moves the limiting member 70 to the limiting position (see Figure 11). In this case, the tip of the limiting member 70 contacts the second contact portion 712 of the pedal receiving member 71. The gear shift pedal 37 can be pressed within the range until the lower surface of the gear shift pedal 37 contacts the third contact portion 723 of the protruding member 72.

[0056] When it is necessary to fix the gear shift pedal 37 in a limited position, such as during maintenance of the work machine 3, the operator engages the hook 37F of the gear shift pedal 37 with the third contact portion 723 of the protruding member 72, with the limiting member 70 raised above the limiting position, as shown in Figure 10.

[0057] To release the lock on the amount of pedal travel, lightly press down on the gear shift pedal 37. This loosens the engagement between the hook 37F and the third contact portion 723. Because the tension spring 70T biases the limiting member 70 toward the limiting position, the third contact portion 723 disengages from the hook 37F, and as shown in Figure 8, the tension spring 70T pulls the limiting member 70 toward the limiting position.

[0058] The agricultural vehicle 1 according to the embodiment described above includes a gear shift pedal 37 (an example of an operating tool) used to adjust the driving speed of at least one of the vehicle body 2 and the work machine 3, a limiting member 70 that contacts the gear shift pedal 37 within its movable range to limit the amount of operation of the gear shift pedal 37, and an engaging means 80 that engages the gear shift pedal 37 with the limiting member 70 to fix the gear shift pedal 37 at a predetermined amount of operation. With this configuration, the driving speed can be limited and fixed with a simple configuration.

[0059] Furthermore, according to the agricultural vehicle 1 of this embodiment, the predetermined operating amount is less than or equal to the operating amount limited by the limiting member 70. This configuration enhances safety.

[0060] Furthermore, according to the agricultural vehicle 1 of this embodiment, a support body 40 is provided to support the gear shift pedal 37 and the limiting member 70, and the limiting member 70 is movable between a limiting position in which it contacts the gear shift pedal 37 to limit the amount of operation of the gear shift pedal 37 within its movable range, and a retracted position in which it does not contact the gear shift pedal 37. With this configuration, the limiting member 70 can be quickly switched between the contact position and the non-contact position.

[0061] Furthermore, according to the agricultural vehicle 1 of this embodiment, a tension spring 70T is provided, with one end connected to a support 40 and the other end connected to a limiting member 70. The limiting member 70 is pivotable between a restricted position and a retracted position around a first shaft 701. The tension spring 70T is in its most extended neutral position when its centerline, viewed from the axial direction of the first shaft 701, coincides with the first shaft 701. The restricted position and the retracted position are located in opposite directions with the neutral position in between, and the tension spring 70T biases the limiting member 70 towards either the restricted position or the retracted position. With this configuration, the limiting member 70 can be kept in the restricted position and the retracted position with a simple configuration.

[0062] Furthermore, according to the agricultural vehicle 1 of this embodiment, the gear shift pedal 37 is pivotable about a second shaft 372 parallel to the first shaft 701 and is biased in a direction that reduces the amount of operation. When the gear shift pedal 37 and the limiting member 70 are engaged by the engagement means 80, the limiting member 70 is biased toward the limiting position by the tension spring 70T. When the gear shift pedal 37 is operated toward the limiting position from the state in which the gear shift pedal 37 and the limiting member 70 are engaged by the engagement means 80, the engagement by the engagement means 80 is released. With this configuration, the amount of operation can be released by operating the gear shift pedal 37. Also, since the limiting member 70 moves to the limiting position, the drive speed can be limited. [Explanation of Symbols]

[0063] 1. Agricultural vehicles 2. Running body 3. Work equipment 37. Gear shift pedal (operating device) 372 2nd axis 40 Support 70 Restricting member 701 1st axis 70T tension spring 80 Engaging means

Claims

1. A gear shift pedal used to adjust the drive speed of at least one of the vehicle and the work equipment, A limiting member that limits the amount of operation of the gear shift pedal by contacting the gear shift pedal within the range of motion of the gear shift pedal, An engaging means for fixing the gear shift pedal to a predetermined operating amount by engaging the gear shift pedal with the limiting member, A support that supports the gear shift pedal and the limiting member, A tension spring having one end connected to the support and the other end connected to the limiting member, The limiting member is movable within the movable range between a limiting position that limits the amount of operation of the gear shift pedal by contacting it, and a retracted position that does not contact the gear shift pedal, and is swingable between the limiting position and the retracted position about the first axis. The aforementioned limiting position and the aforementioned retracted position are located in opposite directions with respect to the first axis. The aforementioned tension spring biases the limiting member to either the limiting position side or the retracted position side, making it an agricultural vehicle.

2. The gear shift pedal is pivotable about a second axis parallel to the first axis and is biased in a direction that reduces the amount of operation. When the gear shift pedal and the limiting member are engaged by the engagement means, the limiting member is biased toward the limiting position by the tension spring. The agricultural vehicle according to claim 1, characterized in that when the gear shift pedal is operated toward the restricted position from a state in which the gear shift pedal and the restricting member are engaged by the engaging means, the engagement by the engaging means is released.

3. The agricultural vehicle according to claim 1 or 2, characterized in that the predetermined operating amount is less than or equal to the operating amount limited by the limiting member.

4. The agricultural vehicle according to claim 1 or 2, characterized in that the limiting member is located in the neutral position where the tension spring is most extended when the center line of the tension spring coincides with the first axis when viewed from the axial direction of the first axis.

Images