JP2024083879A - Agricultural vehicles - Google Patents

Abstract

An object of the present invention is to limit and fix the drive speed with a simple configuration.
[Solution] The agricultural work vehicle is equipped with a speed change pedal 37 (an example of an operating tool) used to adjust the drive speed of at least one of the running body and the work machine, a limiting member 70 that limits the amount of operation of the speed change pedal 37 by contacting the speed change pedal 37 within the movable range of the speed change pedal 37, and an engagement means 80 that fixes the speed change pedal 37 to a predetermined amount of operation by engaging the speed change pedal 37 with the limiting member 70.
[Selected figure] Figure 5

Description

The present invention relates to an agricultural vehicle.

Technologies for limiting the travel speed of agricultural vehicles have been considered in the past. For example, Patent Document 1 proposes an agricultural vehicle that includes a speed change pedal that is attached to a vehicle frame and that can change the travel speed depending on the amount of rotation caused by depressing the pedal, a pedal receiver that protrudes from the vehicle frame and has a first receiving portion on its upper surface that abuts against the speed change pedal, a rotating member that is movably supported at one end by the pedal receiver so that it can be positioned at an abutment position where it protrudes toward the speed change pedal from the first receiving portion and can abut against the speed change pedal, and at a non-abutment position where it is tilted toward the vehicle frame from the first receiving portion and cannot abut against the speed change pedal, and a second receiving portion that abuts against the speed change pedal at the abutment position, and an elastic member that is connected to the rotating member and the pedal receiver so that the rotating member crosses the fulcrum of the rotating member when it is rotated from the non-abutment position to the abutment position.

International Publication No. 2015/147109 JP 2012-95574 A

The driving force generated by the driving source is used to drive the agricultural vehicle and also to drive the working equipment. For example, in the case of a planting device of a rice transplanter, the planting device is driven at a planting speed that corresponds to the traveling speed while the rice transplanter is traveling.

However, there are cases where the planting device is driven without the rice transplanter running. For example, when washing the planting device, the transmission is put into neutral to cut off the driving force to the wheels, and the planting device is driven at a speed slower than the normal planting speed while being washed by pouring water on it. In order to maintain a planting speed slower than the normal planting speed in the configuration described in Patent Document 1, it is necessary to keep the speed change pedal depressed to the position where it abuts on the second receiving part, making it difficult for one person to wash the planting device. In response to this, Patent Document 2 proposes a configuration that includes an actuator that adjusts the engine speed and adjusts the actuator drive amount according to the maximum speed set using a dial, but this configuration may increase costs.

The present invention takes the above circumstances into consideration and aims to provide an agricultural vehicle that can limit and fix the drive speed with a simple configuration.

To solve the above problems, the agricultural work vehicle according to the present invention is equipped with an operating tool used to adjust the drive speed of at least one of the running 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 engagement means that fixes the operating tool to a predetermined amount of operation by engaging the operating tool with the limiting member.

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

The agricultural work vehicle may include a support 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.

The agricultural work 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, and the limiting member is capable of swinging between the limiting position and the retracted position around a first axis, and when the center line of the tension spring overlaps with the first axis as viewed from the axial direction of the first axis, the tension spring is positioned in a neutral position where it is most extended, and the limiting position and the retracted position are positioned in opposite directions with respect to the neutral position, and the tension spring may bias the limiting member toward either the limiting position side or the retracted position side.

The operating tool can swing 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. 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, the engagement by the engaging means may be released.

The present invention allows the drive speed to be limited and fixed with a simple configuration.

1 is a left side view showing an agricultural work vehicle according to an embodiment of the present invention. FIG. 1 is a plan view showing an agricultural work vehicle according to an embodiment of the present invention. 1 is a plan view showing a power transmission mechanism of an agricultural work vehicle according to an embodiment of the present invention. FIG. 2 is a plan view showing a speed change mechanism and a brake mechanism according to an embodiment of the present invention. 1 is a perspective view showing a speed change pedal according to an embodiment of the present invention; FIG. 2 is a right side view showing a speed change pedal according to one embodiment of the present invention. FIG. 2 is a right side view showing a speed change pedal according to one embodiment of the present invention. 11 is a left side view showing a state in which the limiting member according to the embodiment of the present invention is located at a retracted position. FIG. FIG. 4 is a left side view showing a state in which the limiting member according to the embodiment of the present invention is located at a neutral position. FIG. 11 is a left side view showing a state in which the limiting member according to the embodiment of the present invention is located at an engagement position. FIG. 11 is a left side view showing a state in which the restricting member according to the embodiment of the present invention is located at a restricting position.

Below, we will explain an agricultural work vehicle 1 according to one embodiment of the present invention with reference to the drawings.

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 respectively indicate up, down, left, right, front, and rear.

The agricultural work vehicle 1 (see Figures 1 to 3) includes a running body 2 and a working machine 3 provided behind the running body 2. For example, the working machine 3 is a planting device that plants rice seedlings, and the agricultural work vehicle 1 is a rice transplanter that runs on the running body 2 while planting seedlings using the working machine 3. The working machine 3 may also be a device that transplants, sows, cultivates, etc. vegetables or grains.

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

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

The rear axle 24 is provided behind the transmission 12 and is connected to the transmission 12 by a joint material 23 whose longitudinal direction is in the front-to-rear direction. The rear wheel drive shaft 25 is provided along the joint material 23 and transmits driving force from the transmission 12 to the rear axle 24. The rear wheels 14 are attached to rear axles 24S provided 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.

The driver's seat 15 is provided above the joint material 23. Around the driver's seat 15, there are a steering handle 16, a gear shift lever (not shown), a gear shift pedal 37 (one example of an operating tool), a brake pedal 38, etc. The front wheels 13 steer the running body 2 in conjunction with the operation of the steering handle 16. The steps 17 (see Figure 2) are flat members that serve as footholds for the operator, and are provided around the driver's seat 15 and on the left and right sides of the bonnet 21. The spare seedling trays 18 are provided on the left and right sides of the bonnet 21, and seedling mats to be replenished to the working machine 3 are placed on them.

The inter-row transmission 27 (see FIG. 3) is located above the rear axle 24, to the right of the center in the left-right direction. The inter-row transmission 27 changes the speed of the driving force input from the transmission 12 via the drive shaft 35A, and outputs it to the work machine 3 via the drive shaft 35B.

The working machine 3 comprises a seedling carrier 30 on which the seedling mat is placed, and a main frame 31. The main frame 31 is a rod-shaped member with its longitudinal direction in the left-right direction, and has a center case 33 in the left-right center. Planting transmission cases 34 are provided at roughly equal intervals at multiple locations (four locations in this example) in the left-right 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.

The input shaft 33A of the center case 33 is connected to the drive shaft 35B via a universal joint. The center case 33 is equipped with a gear train (not shown) including a bevel gear. The output shaft 33B of the center case 33 is provided along the main frame 31 and is 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 case 34. The working machine 3 is equipped with a lateral feed drive unit (not shown) that drives the seedling carrier 30 to move in the left and right directions. In parallel with the seedling carrier 30 reciprocating left and right, the transplanting mechanism 32 removes the seedlings from the seedling carrier 30 and plants them in the field.

The work machine 3 is provided with a lifting device 22. The lifting device 22 includes 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 provided above the rear axle 24. The columnar frame 10P and the seedling carrier 30 are connected by a pair of link members 22L. The joints between the columnar frame 10P, the seedling carrier 30, and the pair of link members 22L form the four vertices of a parallelogram. The hydraulic cylinder 22C is connected to the joint material 23 and the lower link member 22L. The hydraulic cylinder 22C expands and contracts, causing the pair of link members 22L to swing around the joints on the columnar frame 10P side as fulcrums, thereby raising and lowering the seedling carrier 30.

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 formed by combining tubular members whose longitudinal directions are mainly in the front-rear or left-right directions. The gear shift pedal 37 (an example of an operating tool) and the brake pedal 38 are provided to the right front of the driver's seat 15. The brake pedal 38 is provided to the left of the gear shift pedal 37.

[Transmission mechanism]
The speed change mechanism 4 (see FIG. 4 ) includes an HST 41 (hydraulic static transmission), a planetary gear mechanism (not shown), a stepped transmission (not shown), and a speed change pedal 37. The HST 41, the planetary gear mechanism, and the stepped transmission are provided below the support 40. The HST 41 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 a planetary carrier provided in the planetary gear mechanism. The hydraulic motor 41M is driven by the hydraulic pump 41P discharging hydraulic oil to the hydraulic motor 41M. The discharge amount of hydraulic oil is adjusted by changing the angle of a 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 speed change pedal 37. The hydraulic motor 41M drives a sun gear provided in the planetary gear mechanism.

When the speed change pedal 37 is not depressed (maximum raised state), the swash plate is at its maximum inclination and the hydraulic motor 41M rotates at its highest speed. In this case, the planetary gear and the sun gear cancel each other out, causing the ring gear to stop. As the amount of depression of the speed change pedal 37 (an example of the amount of operation of an operating tool) increases relative to the maximum raised state, the inclination angle of the swash plate decreases, and the rotation speed of the hydraulic motor 41M and the sun gear decreases, so the rotation speed of the ring gear increases.

The stepped transmission has 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 shifted by changing the gear ratio of the gear train in response to the operation of the shift lever.

The speed change pedal 37 (see Figures 4 to 7) is attached to a speed change pedal support member 37S provided on the support body 40. The rear end of the speed change pedal 37 is hinged to the speed change pedal support member 37S via a second shaft 372 whose axial direction is in the left-right direction, and the speed change pedal 37 can swing around the second shaft 372. The speed change pedal 37 is operated within a predetermined movable range inclined so that the front side is higher than the rear side.

An arm 42 (see Figures 6 and 7) with its longitudinal direction extending in the front-rear direction is provided in front of the speed change pedal 37. The front end of the arm 42 is supported by the support body 40 via an arm shaft 42S with its axial direction extending in the left-right direction, and the arm 42 can swing around the arm shaft 42S. A boss 40B that protrudes to the right is provided in front of the arm shaft 42S of the support body 40. A boss 42B that protrudes to the right is provided at the rear end of the arm 42. A tension spring 42T is connected to the two bosses 40B, 42B. The tension spring 42T is a tension coil spring.

A protrusion 37T that protrudes downward is provided forward of the center of the underside of the speed change pedal 37. A speed change rod 43 is swingably connected to the protrusion 37T and the rear end of the arm 42.

When the speed change pedal 37 is in the uppermost position (see FIG. 6), the center line 42C of the tension spring 42T overlaps with the arm shaft 42S when viewed from the right, so the tension spring 42T is in the most extended state and the tension force P is at the maximum value Pmax. As the speed change pedal 37 is depressed (see FIG. 7), the tension spring 42T contracts, so the tension force P decreases. The pedal force N acts in a direction perpendicular to the upper surface of the speed change pedal 37. If the angle between the direction of the pedal force N and the longitudinal direction of the speed change rod 43 is θ, the component force Ncosθ of the pedal force N in the longitudinal direction of the speed change rod 43 acts on the rear end of the arm 42. As a result, the resultant force of the tension 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 depression of the speed change pedal 37.

The front end of a speed change rod 44 (see Figs. 4, 6, and 7), whose longitudinal direction is in the front-rear direction, is swingably connected to the lower front part of the arm 42. An L-shaped pivot 45 (see Fig. 4) is provided behind the speed change 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-down direction, and can swing around the axis 45S. The rear end of the speed change rod 44 is swingably connected to one end of the pivot 45. The right end of a speed change rod 46, whose longitudinal direction is in the left-right direction, is swingably connected to the other end of the pivot 45.

The trunnion shaft 41T (see FIG. 4) is provided with its axial direction extending vertically. An operating arm 41A is provided on the trunnion shaft 41T. The operating arm 41A has a protruding portion 41B that protrudes rearward from the trunnion shaft 41T and a protruding portion 41C that protrudes to the right of the trunnion shaft 41T. The left end of the speed change rod 44 is swingably connected to the protruding portion 41B.

One end of the return spring 47 is connected to the protruding portion 41C. The other end of the return spring 47 is connected to the support body 40 on the left rear side of the protruding portion 41C. The return spring 47 is a tension coil spring, and urges the operating arm 41A in a clockwise direction in FIG. 4. When the operating arm 41A swings in a clockwise direction, the shift rod 46 is pulled to the left, so that the pivot 45 swings in a clockwise direction and the shift rod 44 is pulled backward. As a result, the arm 42 swings in a clockwise direction in FIG. 7 (see FIG. 6), and the shift pedal 37 is pushed up via the shift rod 43 (see FIG. 6). In other words, the return spring 47 urges the shift pedal 37 in a direction (upward) that reduces the amount of depression.

When the speed change pedal 37 is depressed, the arm 42 swings counterclockwise in FIG. 6 via the speed change rod 43 (see FIG. 7), pulling the speed change rod 44 forward. This causes the pivot 45 to swing counterclockwise in FIG. 4 and pull the speed change rod 46 to the right, causing the operating arm 41A to swing counterclockwise in FIG. 4 and operating the trunnion shaft 41T in the counterclockwise direction. When the force applied to the speed change pedal 37 is reduced, the return spring 47 causes the operating arm 41A to swing clockwise, pushing up the speed change pedal 37 as described above.

[Brake mechanism]
A brake (not shown) is provided on the output shaft of the stepped transmission. The brake has a brake shaft 51 (see FIG. 4) whose axial direction is the up-down direction, and is actuated by rotating the brake shaft 51 using the brake pedal 38.

The brake pedal 38 is connected to the support body 40 via a brake pedal shaft 38S whose axial direction is in the left-right direction, and can swing around 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 wound around the brake pedal shaft 38S. A brake rod 52 whose longitudinal direction is in the front-rear direction is swingably connected to the brake pedal 38 at a location above the brake pedal shaft 38S.

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

When the brake pedal 38 is depressed, the brake rod 52 is pulled forward, causing the contact portion 52C to swing the brake arm 53 counterclockwise in FIG. 4 and rotate the brake shaft 51 counterclockwise, thereby activating the brake.

When the temperature of the hydraulic oil rises, the oil pressure inside the HST 41 may rise even when the shift pedal 37 is not depressed, and the driving force may be transmitted to the front wheels 13, rear wheels 14, and work equipment 3. To prevent this phenomenon, a structure is provided that slightly rotates the brake shaft 51 to cancel the driving force of the output shaft of the stepped transmission when the shift pedal 37 is not depressed.

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 a shaft 56S whose axial direction is in the vertical direction, and can swing around the shaft 56S. The left end of the pivot 56 is swingably connected to the protruding portion 41C of the operating arm 41A.

An arm 57 is provided to the rear right of the pivot 56 and to the left of the brake shaft 51. The arm 57 is supported by the support body 40 via a shaft 57S whose axial direction is in the vertical direction, and can swing around the shaft 57S. A rod 58 is swingably 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 located in front of the left end of the leaf spring 55.

When the return spring 47 causes the operating arm 41A to swing clockwise in FIG. 4, the pivot 56 swings counterclockwise, pulling the rod 58 forward and swinging the arm 57 clockwise. As a result, the pressing member 59 presses the leaf spring 55 backward, causing the brake shaft 51 to swing counterclockwise, and the brake is activated.

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

The agricultural work vehicle 1 according to this embodiment is equipped with a speed change pedal 37 (one example of an operating tool) used to adjust the drive speed of at least one of the traveling body 2 and the work implement 3, a limiting member 70 that limits the amount of operation of the speed change pedal 37 by contacting the speed change pedal 37 within the movable range of the speed change pedal 37, and an engagement means 80 that fixes the speed change pedal 37 to a predetermined amount of operation by engaging the speed change pedal 37 with the limiting member 70. More specifically, it is as follows. Note that the speed change pedal 37 has been described above, so the following will mainly describe the limiting member 70 and the engagement means 80.

[Restriction member]
The pedal receiving member 71 is disposed in front of the speed change pedal support member 37S and is attached to the upper surface of the support body 40. A first contact portion 711 that comes into contact with the underside of the speed change pedal 37 when it is depressed is provided at the upper end of the pedal receiving member 71. When the underside of the speed change pedal 37 comes into contact with the first contact portion 711, the speed change pedal 37 cannot be depressed any further. In other words, the amount of depression when the underside of the speed change pedal 37 comes into contact with the first contact portion 711 is the maximum amount of depression of the speed change pedal 37.

The restricting member 70 is a long and thin plate-like member. The restricting member 70 has 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 which connects the base portion 70A and the tip portion 70C. As shown in FIG. 9, when viewed from the left, the intermediate portion 70B is bent in a counterclockwise direction relative to the base portion 70A, and the tip portion 70C is bent in a counterclockwise direction relative 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 portion of the pedal receiving member 71 via a first shaft 701. The first shaft 701 is provided at a position slightly higher than the upper surface of the support body 40.

The restricting member 70 can swing around the first shaft 701 between a retracted position (see FIG. 8) and a restricted position (see FIG. 11). In the retracted position, the vicinity of the connection point between the base 70A and the intermediate portion 70B contacts the upper surface of the support 40. The pedal receiving member 71 is provided with a second contact portion 712 at a position lower than the first contact portion 711 and rearward of the first contact portion 711. In the restricted position, the tip portion 70C contacts the second contact portion 712. A boss 71B protruding to the left is provided at a position diagonally forward and downward from the first shaft 701 of the pedal receiving member 71. In addition, 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.

In the neutral position (see FIG. 9), the center line 70TC of the tension spring 70T overlaps with the first shaft 701 when viewed from the axial direction of the first shaft 701, and the tension spring 70T is in the most extended state. The limiting position (see FIG. 11) and the retracted position (see FIG. 8) are located in opposite directions with respect to the neutral position. The tension spring 70T biases the limiting member 70 toward either the limiting position side or the retracted position side. For example, when an external force acts to swing the limiting member 70 toward the retracted position side in the neutral position, the tension spring 70T retracts the limiting member 70 to the retracted position. On the other hand, when an external force acts to swing the limiting member 70 toward the limiting position side in the neutral position, the tension spring 70T retracts the limiting member 70 to the limiting position.

The tip 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 70C is provided with a hole (not shown) that penetrates in the thickness direction. The protruding member 72 includes a support portion 72A that is inserted into the hole, and a third contact portion 723 that is provided at the tip of the support portion 72A with the left-right direction as the longitudinal direction. The third contact portion 723 has a length equal to the left-right width of the shift pedal 37, and has equal lengths 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 shift pedal 37 and the third contact portion 723 is equal on the left and right sides of the support portion 72A, so that the shift pedal 37 is prevented from tipping over to the left and right. In the limiting position, the lower surface of the shift pedal 37 contacts the third contact portion 723, limiting the amount of depression of the shift pedal 37 to less than the maximum amount of depression.

The support column 72A is provided with a screw groove. The support column 72A is fixed to the tip portion 70C by tightening nuts from the speed change pedal 37 side and the pedal receiving member 71 side. By shifting the position of the nut in the axial direction relative to the support column 72A, the amount of protrusion of the protruding member 72 is adjusted, and therefore the amount of restriction of the depression amount by the restricting member 70 is adjusted.

[Engagement Means]
A hook 37F that protrudes downward is provided on the protruding portion 37T of the speed change pedal 37. When the hook 37F is engaged with the third contact portion 723 at an engagement position (see FIG. 10 ) between the limit position and the retracted position, the force of the return spring 47 returning the speed change pedal 37 and the force of the tension spring 70T biasing the speed change pedal 37 downward are balanced, and the amount of depression of the speed change pedal 37 is fixed. The hook 37F and the third contact portion 723 are one example of engagement means 80.

Next, the operation of the above configuration will be described. When there is no need to limit the amount of depression of the speed change pedal 37, the driver moves the limiting member 70 to the retracted position (see FIG. 8). The limiting member 70 is moved with a hand or a toe. In this case, the speed change pedal 37 can be depressed up to the point where the underside of the speed change pedal 37 comes into contact with the first contact portion 711 of the pedal receiving member 71.

When it is necessary to limit the amount of depression of the speed change pedal 37, such as when planting at a slower than normal speed, the driver moves the limiting member 70 to the limiting position (see FIG. 11). In this case, the tip of the limiting member 70 comes into contact with the second contact portion 712 of the pedal receiving member 71. The speed change pedal 37 can be depressed up to the point where the underside of the speed change pedal 37 comes into contact with the third contact portion 723 of the protruding member 72.

When it is necessary to fix the speed change pedal 37 in a state where the amount of depression is limited, such as during maintenance of the work machine 3, the driver raises the limiting member 70 from the limit position and engages the hook 37F of the speed change pedal 37 with the third contact portion 723 of the protruding member 72, as shown in FIG. 10.

To release the fixed amount of depression, the speed change pedal 37 is lightly depressed. 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 the tension spring 70T pulls the limiting member 70 toward the limiting position, as shown in FIG. 8.

The agricultural work vehicle 1 according to the present embodiment described above includes a speed change pedal 37 (one example of an operating tool) used to adjust the drive speed of at least one of the traveling body 2 and the work implement 3, a limiting member 70 that limits the amount of operation of the speed change pedal 37 by contacting the speed change pedal 37 within the movable range of the speed change pedal 37, and an engagement means 80 that fixes the speed change pedal 37 to a predetermined amount of operation by engaging the speed change pedal 37 with the limiting member 70. This configuration makes it possible to limit and fix the drive speed with a simple configuration.

In addition, with the agricultural work vehicle 1 according to this embodiment, the predetermined operation amount is equal to or less than the operation amount limited by the limiting member 70. With this configuration, safety can be improved.

The agricultural work vehicle 1 according to this embodiment is equipped with a support 40 that supports the speed change pedal 37 and the limiting member 70, and the limiting member 70 is movable between a limiting position where the limiting member 70 contacts the speed change pedal 37 within its movable range to limit the amount of operation of the speed change pedal 37, and a retracted position where the limiting member 70 does not contact the speed change pedal 37. With this configuration, the limiting member 70 can be quickly switched between the contact position and the non-contact position.

The agricultural work vehicle 1 according to this embodiment is equipped with a tension spring 70T, one end of which is connected to the support 40 and the other end of which is connected to the restricting member 70. The restricting member 70 can swing between a restricting position and a retracted position around the first shaft 701. When the center line of the tension spring 70T overlaps with the first shaft 701 as viewed from the axial direction of the first shaft 701, the tension spring 70T is in its most extended neutral position. The restricting position and the retracted position are located in opposite directions with respect to the neutral position, and the tension spring 70T biases the restricting member 70 toward either the restricting position side or the retracted position side. This configuration allows the restricting member 70 to be held in the restricting position or the retracted position with a simple configuration.

In addition, according to the agricultural work vehicle 1 of this embodiment, the speed change pedal 37 can swing around the second shaft 372 parallel to the first shaft 701, and is biased in a direction to reduce the amount of operation. When the speed change 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 speed change pedal 37 is operated toward the limiting position from a state in which the speed change 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 fixed amount of operation can be released by operating the speed change pedal 37. Also, because the limiting member 70 moves to the limiting position, the drive speed can be limited.

1 Agricultural work vehicle 2 Traveling body 3 Working machine 37 Speed change pedal (operating tool)
372 Second shaft 40 Support 70 Restricting member 701 First shaft 70T Tension spring 80 Engagement means

Claims (5)

an operating tool used for adjusting the drive speed of at least one of the traveling body and the working machine;
a limiting member that limits an amount of operation of the operating tool by contacting the operating tool within a movable range of the operating tool;
an engagement means for engaging the operating tool with the limiting member to fix the operating tool at a predetermined operation amount. The agricultural vehicle according to claim 1, characterized in that the predetermined operation amount is equal to or less than the operation amount limited by the limiting member. a support body for supporting the operating tool and the limiting member,
3. The agricultural work vehicle according to claim 1, wherein the limiting member is movable between a limiting position where the limiting member contacts the operating tool within the movable range to limit an amount of operation of the operating tool, and a retracted position where the limiting member does not contact the operating tool. a tension spring having one end connected to the support and the other end connected to the restricting member;
the limiting member is capable of swinging about a first axis between the limiting position and the retracted position, and the tension spring is positioned at a neutral position where the tension spring is most extended when a center line of the tension spring overlaps with the first axis as viewed in the axial direction of the first axis,
The limit position and the retracted position are located in opposite directions to each other with the neutral position in between,
4. The agricultural work vehicle according to claim 3, wherein the tension spring biases the restricting member toward either the restricting position or the retracted position. the operating tool is swingable about a second axis parallel to the first axis and is biased in a direction to reduce an amount of operation,
When the operating tool and the limiting member are engaged with each other by the engaging means, the limiting member is biased toward the limiting position by the tension spring,
5. The agricultural work vehicle according to claim 4, wherein when the operating tool and the limiting member are engaged by the engagement means and the operating tool is operated toward the limiting position, the engagement by the engagement means is released.

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