JP2003220849A - Running speed retaining mechanism - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable operating of a lever not only with a pedal to release a running speed retaining mechanism. <P>SOLUTION: The running speed retaining mechanism retains a vehicle speed by engaging a locking part 109a of a gear shifting cam 109 coupled to a gear shifting pedal 31 with a pawl 102a of a speed holding cam 102 coupled to a speed holding lever 54 arranged near a brake pedal 30 and a steering handle 14 and holding the pedal 31 at a predetermined operating position in a running vehicle 1 having the pedal 30 and the pedal 31. Thus, the holding mechanism can be switched to states of operating or releasing (holding or non-holding) of the holding mechanism even by any of the lever 54, the pedal 30 and the pedal 31. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a work vehicle such as a rice transplanter, a tractor, a combine, or a civil engineering construction machine, which is equipped with a seedling table and a nail for planting seedlings and which continuously performs seedling work, at a constant speed. The present invention relates to a speed holding mechanism for causing the movement.

[0002]

2. Description of the Related Art Generally, a traveling speed holding mechanism (auto cruise mechanism), which is provided in a work vehicle such as a rice transplanter or a tractor, for keeping the vehicle speed constant, has been proposed and implemented in various structures. However, the release of the holding mechanism, that is,
When the vehicle speed is switched from the holding state to the non-holding state, only the pedal operation with the operator's foot is required, such as depressing the accelerator pedal, the speed change pedal, or the brake pedal.

[0003]

However, in the case of releasing the traveling speed holding mechanism by depressing the accelerator pedal, there is no problem when accelerating, but when decelerating, the holding mechanism is released. At the time of operation, contrary to the intention of the operator who tries to decelerate, there is a problem that the operator temporarily accelerates and the operation feeling of the operator does not match. In addition, by depressing the brake pedal, the running speed holding mechanism is released, and in particular, the brake pedal is used to operate the brake and the clutch so that the brake operates before the clutch. In the case of a vehicle having such a structure, the brake is actuated when the holding mechanism is released, and a shock occurs when the vehicle is braked.

[0004]

The problem to be solved by the present invention is as described above, and the means for solving this problem will be described below.

That is, in claim 1, a traveling vehicle provided with a holding mechanism for holding the speed change pedal at a constant operation position is provided with an operation lever capable of switching the holding mechanism to a holding or non-holding state. is there.

According to a second aspect of the present invention, in the traveling speed holding mechanism according to the first aspect, the holding mechanism includes a gear shift operation member having a pawl portion provided on the side of the speed change pedal, and an engagement for engaging the pawl portion. The holding operation member is provided with a section, and the holding operation member and the operation means are connected by an elastically deformable member.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Next, embodiments of the present invention will be described. 1 is a plan view showing the overall structure of the rice transplanter according to this embodiment, FIG. 2 is a side view of the same, FIG. 3 is a plan view of a vehicle body frame, FIG. 4 is an explanatory side view of a drive unit, and FIG. It is an explanatory plan view of a drive part. 6 is a sectional view of the mission case, FIG. 7 is a skeleton diagram of the mission case, FIG. 8 is an explanatory diagram of the main clutch, FIG. 9 is an explanatory diagram of the brake device, and FIG. 10 is an explanatory diagram of the PTO transmission mechanism. And FIG.
FIG. 12 is a right side view showing the speed maintaining mechanism, FIG. 12 is a perspective view showing a brake pedal and a speed change pedal, FIG. 13 is a right side view, FIG. 14 is a same plan view, and FIG. 15 is a left side view showing a speed change pedal. 16 is a perspective view showing a pedal support portion of a vehicle body frame, FIG. 17 is a left side view showing a brake pedal, FIG.
8 is a perspective view of the same, and FIG. 19 is a perspective view of a holding operation lever.

First, the structure of the riding rice transplanter according to the embodiment of the present invention will be described. However, the traveling speed holding mechanism according to the present invention is not limited to this embodiment, and can be applied to various work vehicles.

As shown in FIGS. 1, 2 and 5, in the passenger rice transplanter, the engine 2 is mounted on the vehicle body frame 3 of the traveling vehicle 1.
The left and right sides of the mission case 4 support front wheels 6, 6 for traveling paddy fields via front axle cases 5, 5, and rear axle cases 7 behind the mission case 4 (Fig. 4) are used for rearing paddy fields. It supports the wheels 8 and 8. Preliminary seedling mounts 10 and 10 are attached to both sides of the hood 9 that covers the engine 2 and the like, the mission case 4 and the like are covered by a vehicle body cover 11 on which an operator rides, and a seat frame 12 is provided above and behind the vehicle body cover 11. A driver's seat 13 is attached by means of a steering handle 14 in front of the driver's seat 13 at the rear of the hood 9.

In the vicinity of the position of the steering handle 14, a main gear shift lever 28, a shift lever 29 for operating up / down / shifting / on / off of planting / shifting at planting / drawing markers, an accelerator lever 51, and a speed holding lever. 54 levers 28 and 29
・ 51 ・ 54, brake pedal 30, speed change pedal 31
And each pedal 30, 31, 32 of the diff lock pedal 32
In addition, the sensitivity adjusting lever 33, the stop lever 34, and the unit clutch lever 35 are provided in the vicinity of the position of the driver's seat 13.

Reference numeral 15 in the figure is a seedling table 16 for six-row planting.
In addition, it is a planting part equipped with a plurality of seedling planting claws 17, 17, ...
6 is supported by the planting case 20 via the lower rail 18 and the guide rail 19 so as to be slidable left and right, and also supports the rotary cases 21, 21 ... Which are rotated in one direction by the planting case 20 at a constant speed. is doing. The planted case 2
The 0 front hitch bracket 23 is connected to the rear side of the traveling vehicle 1 via an elevating link mechanism 26 including a top link 24 and a lower link 25, and raises and lowers the planting part 15 via the elevating link mechanism 26. 27 is connected to the lower link 25.

A pair of claw cases 22 and 22 are arranged symmetrically with respect to the rotary shaft center of the rotary case 21, and the claws 17 and 17 with seedlings are attached to the tips of the claw cases 22 and 22. At the same time as the front-rear transportation 6, 6, 8, 8 is driven to move, at the same time, the seedlings for one strain are taken out from the seedling platform 16 that slides back and forth to the left and right by the planting claws 17 and 17 continuously. It is configured to perform rice planting work.

In the figure, 36 is a center float and 37
-37 is a side float, 38 is the fertilizer in the fertilizer hopper 39, and the flexible transport hose 4 is fed by the blower wind of the blower 40.
It is a side-row fertilizer applicator for 6 rows that is discharged to the side-row grooving device 42 of the floats 36, 37, 37 via 1.

Next, the frame structure of the riding rice transplanter will be described.

As shown in FIGS. 3 to 5, the vehicle body frame 3 includes front frames 43, 43 and intermediate frames 44.4.
4 and rear frames 45, 45 are divided into three parts, the left and right front frames 43, 43 for the engine 2 and the left and right intermediate frames 44, 44 for the front axle case 5.5.
Is a pair of left and right rear frames 45, 45 and a fuel tank 4 for supplying fuel to the rear axle case 7 and the engine 2.
6 are arranged.

The front axle cases 5 and 5 are detachably fixed to the lower surfaces of the left and right intermediate frames 44 and 44 connecting the rear ends of the front frames 43 and 43 and the front ends of the rear frames 45 and 45, respectively. The 5 and 5 are connected by the mission case 4.

Further, the rear axle case 7 is fixed to a portal frame 53 integrally connecting the rear portions of the rear frame 45. The mission case 4 and the rear axle case 7 are integrally connected by a connecting frame 62 made of pipe.

A rear output shaft 63 projecting to the rear of the transmission case 4 is connected to a rear input shaft 65 projecting to the front of the rear axle case 7 via a rear transmission shaft 66 so that the left and right rear wheels 8 from the rear output shaft 63. 8 is transmitting power. Further, a PTO output shaft 64 projecting to the rear of the mission case 4 is connected via a universal vertical shaft 69 to an intermediate shaft 68 provided on a bearing 67 above the rear axle case 7, and the intermediate shaft 68 is connected to the intermediate shaft 68 via the universal vertical shaft. The input shaft of the planting case 20 is connected to transmit power from the PTO output shaft 64 to the planting unit 15.

Next, the power transmission structure will be described.

As shown in FIGS. 4 to 7, the mission case 4 includes a main body portion 70, a front lid portion 71, and a rear lid portion 7.
2, the lid portions 72 are detachably fixed to the front and rear of the body portion 70 by bolts to form a closed box, and a partition wall portion 73 that divides the inside of the body portion 70 into the front and rear is provided. .

On the front surface of the front cover 71 of the transmission case 4, a hydraulic continuously variable transmission mechanism 57 including a variable displacement hydraulic pump 85 and a fixed displacement hydraulic motor 86 is arranged.
A shift input pump shaft 58 for inputting to the hydraulic pump 85 is projected forward. The variable speed input pump shaft 58
Is transmitted through the transmission shaft 59 and the transmission belt 61 to the engine 2
Is connected to the output shaft 60 of the engine 2 and power can be taken out from the engine 2.

As described above, the power input from the engine 2 to the speed change input pump shaft 58 drives the hydraulic pump 85, and the pressure oil from the hydraulic pump 85 is sent to the hydraulic motor 86 to drive the motor shaft 77. Is output by rotating. The pump shaft 58 protruding into the transmission case 4 supports the small-diameter transmission gear 74 bearing-bearing on the front lid portion 71 as an engaging shaft.
The power of the transmission gear 74 is transmitted to the charge pump 75 fixed to the rear surface of the rear lid portion 72 via the pipe shaft 76.

On the other hand, the motor shaft 77 of the hydraulic continuously variable transmission mechanism 57 protruding into the transmission case 4 is provided with a front cover portion 7.
The sun gear 78 bearing-bearing the bearing 1 supports the engaging shaft. Further, three planetary gears 80 are attached to a carrier gear 79, which is rotatably supported by a boss portion of the sun gear 78, by a shaft 81.
The planetary gear 80 is rotatably provided via a ring gear 82 fitted externally to a composite output shaft 84 which is rotatably supported by the sun gear 78 and the rear lid portion 72 in the front and rear directions. The gears 78, 80 and 82 form a planetary gear mechanism 83.

A large-diameter carrier gear 79 is constantly meshed with the small-diameter transmission gear 74 externally fitted to the pump shaft 58 to provide a forward and reverse rotation output which is a continuously variable transmission output of the hydraulic continuously variable transmission mechanism 57. , The decelerated rotation output of the transmission gear 74 and the carrier gear 79 (constant rotation in one direction) are combined by the differential action of the planetary gear mechanism 83, and transmitted to the combined output shaft 84 as a rotational force in one direction of zero to maximum speed. ing.

As shown in FIG. 8, the ring gear 82
The main clutch 47 is provided between the composite output shaft 84 and the composite output shaft 84. The ring gear 82 is composed of a gear portion 82 a that meshes with the planetary gear 80 and a boss portion 82 b that loosely fits into a spline collar 140 that spline-fits to the composite output shaft 84, and a clutch arm 48 a pivotally connected to the clutch shaft 48. By sliding the shifter 49 loosely fitted to the spline collar 140 by means of a steel ball between the boss 82b and the spline collar 140, the connection / disconnection, that is, the on / off of the main clutch 47 is controlled. It constitutes a ball clutch mechanism. The clutch shaft 48
Is extended to the outside of the mission case 4, and the clutch arm 48b pivotally connected to the extended portion is connected to the brake pedal 30.
The main clutch 47 can be turned on and off by depressing the brake pedal 30.

The partition wall 7 of the mission case 4
3, the rear portion of the combined output shaft 84, the front output shaft 92, the rear output shaft 63, and the counter shaft 94.
Bearings for each axis.

At the rear of the composite output shaft 84, a forward gear 87 and a reverse gear 88 are supported as idle shafts, and the gears 87 and 88 are selectively engaged with the composite output shaft 84 by a slider 89. The output is switched to forward, neutral or reverse.

In the front output shaft 92, the input gear 9
The power transmitted to the front output shaft 92 by 6 can be transmitted to the left and right front axles 91 via the differential gear 90. Further, a brake device 120 is provided on the front output shaft 92, and as shown in FIG. 9, the brake operation shaft 1 whose upper end extends above the mission case 4.
The operation of the brake device 120 can be controlled by the rotation of the brake device 21, and when the brake device 120 is operated, the braking force acts on the front output shaft 92 to stop the rotation of the front wheels 6.

On the rear output shaft 63, a moving gear 97 and a planting gear 98 are supported as idle shafts, and the auxiliary transmission slider 9 is used.
9, the gears 97 and 98 are selectively engaged with the rear output shaft 63. The auxiliary shift slider 99
The forward / reverse switching slider 89 on the combined output shaft 84 is locked to the same shift fork 106, and forward / backward and auxiliary shifting (low and high speed) are performed by switching the position of the shift lever 28.
Can be switched. In addition, in order to enable the manual rotation of the PTO output shaft 64, the moving gear 97 and the planted gear 9
It is possible to reveal the state in which both 8 idle.

In the counter shaft 94, the transmission gear 141
And high speed gear 100 and PTO transmission gears 93, 93 ...
Is supported by the engaging shaft. PTO gear shifting 93, 93 ...
10 meshes with a plurality of gears 56, 56 ... With different diameters provided on the PTO transmission shaft 116, and by selecting the combination of gears operated by the PTO transmission mechanism 115, , The PTO transmission gear 93
Is transmitted to the PTO output shaft 64, and the planting portion 15 is driven variably between stocks. Further, the fertilizer output shaft 114 is connected to the PTO output shaft 64 via the chain 113 provided inside the mission case 4, and the fertilizer applicator 38 is driven in synchronization with the planting portion 15. Further, the transmission gear 141 includes the forward gear 87 and the high speed gear 1
00 is meshed with the moving gear 97, and is interposed between the combined output shaft 84 and the rear output shaft 63 to transmit power.

In the above structure, the front and rear wheels 6, 6, 8, ...
8 is driven in reverse, the reverse power of the reverse gear 88 on the combined output shaft 84 is applied to the rear output shaft 63 and the front output shaft 92 via the input gears 95 and 96 on the rear output shaft 63 and the front output shaft 92. Communicate to.

When the front and rear wheels 6, 6, 8 and 8 are driven forward at the seedling planting work speed, the low speed PTO transmission gear 93 and the planting gear 98 on the counter shaft 94 are transferred from the transmission gear 141. The power of the forward gear 87 is transmitted to the rear output shaft 63 and the front output shaft 92 via the above. The auxiliary transmission slider 99 is slid to change the speed, and the power of the forward gear 87 is transmitted to the output shafts 63 and 92 via the high speed gear 100 and the moving gear 97, so that high speed such as road movement between fields can be achieved. It is also possible to drive the front-rear transportation 6, 6, 8, 8 forward at a moving speed.

Now, the traveling speed holding mechanism according to the present invention will be described. As shown in FIG. 11 and FIG. 12, the traveling speed holding mechanism is mainly a gear shift operation member connected to the gear shift pedal 31, a gear shift operation cam 109 and a brake pedal 3.
0 and a speed holding operation cam 102 which is a holding operation member connected to the speed holding operation lever 54, and a peripheral mechanism thereof.

First, the shift pedal 31 and its peripheral members will be described.

As shown in FIGS. 7 and 13 to 15, the control shaft 10 for controlling the angle of the swash plate 107 of the hydraulic pump 85.
8 is connected to the shift operation cam 109 via a link 110 composed of an arm 110a and an adjusting rod 110b,
The shift pedal 31 is connected to the shift operation cam 109.

The shift pedal 3 is attached to the shift operation cam 109.
1 and the pedal shaft 10 which is the rotation shaft of the shift operation cam 109
One end of 1 is inserted and fixed, and the other end of the pedal shaft 101 is fixed to the pedal arm 31a of the speed change pedal 31.
b is externally fitted and fixed. That is, when the shift pedal 31 is stepped on, the shift operation cam 109 rotates about the pedal shaft 101, and the control shaft 108 is rotated via a link 110 connected to the shift operation cam 109. The angle of the swash plate 107 of the hydraulic pump 85 is changed.

As shown in FIG. 16, the pedal shaft 101 has a tubular support member 10 that extends right and left through a bracket 132 connecting the front frame 43 and the intermediate frame 44.
3, the pedal portion 31c of the speed change pedal 31 is provided with a stay portion extending between a bracket 132 connecting the front frame 43 and the intermediate frame 44 and a bracket 131 connecting the intermediate frame 44 and the rear frame 45. Thirteen
It is fixed to 9 by bolts 160 and 160. The pedal arm 31a of the speed change pedal 31 forms a link so that the speed change operation cam 109 does not rapidly rotate even when the speed change pedal 31 is suddenly depressed.

In the side view, the speed change operation cam 109 is formed by bulging the upper and lower sides of the pedal shaft 101 outward in an arm shape to form a rod pivot coupling portion 109c and an oil damper pivot coupling portion 109b. A locking portion 109a for protruding the shaft 101 and having a saw-toothed tooth integrally formed at its tip is formed for speed holding operation.

In the oil damper pivoting portion 109b, the pin 104 is inserted into the speed change operation cam 109, and the speed change pedal 31 is released by releasing one end of the oil damper 112 which is a constant speed operation member. One end of a spring 111 for automatically returning to the stop (zero speed) position is pivotally supported, and the oil damper 112 and the spring 111 are arranged to face each other. Then, the shift operation cam 109
The bracket 131 in which the other side of the spring 111 that connects one side to the bottom is provided between the intermediate frame 44 and the rear frame 45.
And the other side of the oil damper 112 connected to the spring 111 of the speed change operation cam 109 so as to face the U-shaped metal fitting 13
It is engaged and connected to the fixing pin 134 on the front frame 43 via 3. In this way, when the foot of the depressing transmission pedal 31 is released, the transmission pedal 31 returns at a gentle, substantially constant speed due to the resistance of the oil damper 112 and the restoring force of the spring 111, and gradually lowers in speed. Is configured as follows.

On the other hand, in the rod pivot portion 109c, the plate-like speed change operation cam 109 is sandwiched by one end of the adjusting rod 110b, and a pin is inserted through these to pivotally support the adjusting rod 110b. There is. By rotating the adjusting rod 110b to adjust the entire length thereof, the transmission pedal 3
It is possible to adjust the operation feeling such as the depression amount of 1 and the operating condition of the control shaft 108 by the shift pedal 31.

A detection rod 109d, which is an object to be detected for detecting the operation position of the shift pedal 31, is fixedly mounted on the shift operation cam 109, and the detection rod 109d contacts the detection arm 105a of the sensor 105. The operation position of the shift operation cam 109 can be detected by.

Next, the brake pedal 30 and its peripheral members will be described.

As shown in FIGS. 11 and 13, the brake pedal 30 is arranged in parallel with the transmission pedal 31. However, the pedal shaft 117, which is the rotating shaft of the brake pedal 30, and the pedal shaft 101 of the transmission pedal 31 are arranged in the same straight line, but are configured as separate bodies. As shown in FIGS. 17 and 18, the pedal portion 30c of the brake pedal 30
The boss portion 30b fixed to the base portion of the pedal arm 30a continuous with the pedal shaft 11 is inserted into the tubular portion 122a of the bracket 122 screwed to the upper surface of the mission case 4.
7 is externally fitted and fixed to one end of the pedal 7, and the pedal shaft 117 is rotated when the brake pedal 30 is depressed.
Further, a clutch operating portion 30d is fixed to the boss portion 30b on the side opposite to the pedal arm 30a.

The clutch operating portion 30d is a member having an L-shaped cross section, and supports one end of an urging member 123 for urging the brake pedal 30 upward at its end, and the clutch operating portion 30d is provided at a midway portion thereof. The rod 12 for adjusting the operation feeling of the brake pedal 30 for adjusting the operation of the brake device 120 and the timing of disengaging the main clutch 47, which will be described later.
It supports one end of 4. The adjusting rod 124 is
The entire length of the adjusting rod 124 can be finely adjusted by adjusting the position of the bolt that penetrates the clutch operating portion 30d and is screwed into the upper end portion thereof.

The adjusting rod 124 and the biasing member 12
All of the lower ends of 3 are connected to a clutch arm 48b fitted on the outside of the mission case 4 on a clutch shaft 48 extending from the inside of the mission case 4 to the outside. As described above, the shift of the shifter 4 that allows the main clutch 47 to be turned on and off by rotating the clutch arm 48b.
Slide 9 Therefore, by depressing the brake pedal 30, the clutch arm 48a externally fitted to the clutch shaft 48 in the transmission case is rotated via the clutch arm 48b, and the shifter 49 is slid to move the main clutch 47. Off, composite output shaft 8
Since the rotation power is not transmitted to the front and rear wheels 6, 6, 8,
The rotation power to 8 is cut off.

On the other hand, as shown in FIGS. 12 and 14, a brake cam 126 is fixedly provided on the left and right sides of the pedal shaft 117 opposite to the brake pedal 30 (on the left side in the traveling direction), and the pedal shaft 117 and the brake cam are fixed. It is configured to rotate together with 126. The brake cam 127 has a brake rod 127 extending rearward.
, And the rear portion of the brake rod 127 is inserted into a brake arm 121a fixed to the extending portion of the brake operating shaft 121 from the mission case 4. The rotation of the brake cam 126 causes the brake rod 127 to rotate.
By moving back and forth and rotating the above-mentioned brake operating shaft 121, the brake device 120 acting on the front output shaft 92 can be operated or stopped.

Therefore, when the brake pedal 30 is stepped on, the brake cam 126 rotates together with the pedal shaft 117 to move the brake rod 127 forward, thereby rotating the brake operating shaft 121 to rotate the brake device 120 to the front. By acting on the output shaft 92,
The vehicle 1 is braked by stopping the rotation of the front wheels 6. It should be noted that the brake cam 126 is provided with a saw blade-shaped engaging portion 126a, and the engaging pawl 135a formed on the parking lever 135 engages with the engaging portion 126a, whereby the brake cam 126 is braked. The device 120 is held in a state of being rotated in the direction in which it operates.

Further, the interlocking plate 1 for interlocking the speed holding operation cam 102 and the brake pedal 30 with the pin 128 inserted into the pedal arm 30a of the brake pedal 30.
One end of 29 is pivotally connected. The pin 128 also functions as an object to be detected by the sensor 130. When the detection arm 130a of the sensor 130 abuts the pin 128, the depression operation of the brake pedal 30 is detected to detect the sensor 130.
Is turned on so that the engine can be started.

Next, the speed holding operation lever 54 will be described. As shown in FIGS. 1, 11 and 19, a speed holding operation lever 54 is provided below the steering handlebar 14, in front of the axle lever 51 and to the side of the shift lever 29 on the steering handlebar 14 side. There is. The operating lever 5
4 is configured to be pivotable back and forth, and an operator seated in the driver's seat 13 to steer the vehicle 1 pulls the speed holding operation lever 54 toward the front side to operate the traveling speed holding mechanism to bring it into a holding state, It is configured so that it is tilted forward to release the traveling speed holding mechanism to be in the non-holding state.

A lever arm 54a is connected to the speed holding operation lever 54, and an end portion of the lever arm 54a is connected to a speed holding operation cam 102 via an operation rod 50 as shown in FIG. As shown in FIGS. 13 and 18, the cam shaft 136 whose one end is fixed to the speed holding operation cam 102 is the pivot body 1 fixed to the lower surface of the front frame 43.
It is rotatably pivotally supported by 37, and thus the speed holding operation cam 102 is supported by the front frame 43.

A biasing member 143 for biasing the lever arm 54a to rotate downward is provided between the speed maintaining lever 54 and the lever arm 54a.
One end of the urging member 143 is located between the speed holding operation lever 54 and the lever arm 54, and is pivotally connected to a bracket 144a that is vertically installed on the lever guide frame 144, while the other end of the biasing member 143 moves the lever arm 54 upward. It is arranged to press from. Therefore, the speed holding operation lever 54 is always urged in the direction of pushing it forward, that is, in the direction of releasing the speed holding mechanism.

As shown in FIGS. 15 and 17, the speed holding operation cam 102 has a claw portion 102a which engages with a locking portion 109a formed on the speed change operation cam 109, an interlocking plate pivoting portion 102b. A rod pivot 102c is formed.

A pin 13 is provided on the interlocking plate pivot 102b.
8 is inserted and the other end of the interlocking plate 129, one end of which is pivotally connected to the pedal arm 30a of the brake pedal 30, is pivotally connected thereto. Interlocking plate 1 for penetrating the pin 138
The hole 129a formed in the hole 29 has a long hole shape, and even if the speed holding operation cam 102 rotates in a direction to release the engagement with the speed change operation cam 109, the brake pedal 30 is not operated in conjunction with this. I am trying.

The lower end of the operating rod 50 is rotatably connected to the rod connecting portion 102c. The operation rod 50 is made of an elastically deformable material (for example, spring steel or the like), and has a bent shape in the middle. Therefore, when the locking portion 109a of the speed change operation cam 109 and the claw portion 102a of the speed hold operation cam 102 do not engage in a good state, the speed hold operation lever 54 is forcibly operated, or the speed hold operation is performed. Even if the lever 54 is erroneously operated, the operation rod 50 is elastically deformed, so that it is possible to prevent the shift operation cam 109, the speed holding operation cam 102, and the speed holding operation lever 54 from being applied with a load equal to or more than the set load. .

The claw portion 102a is provided with the speed change operation cam 109.
It is shaped so as to fit into the shape of the engaging portion 109a provided with saw-toothed teeth formed on the above, and further, an inclined surface is formed on the upper surface of the engaging portion with the engaging portion 109a. Therefore, the locking portion 109a of the speed change operation cam 109 and the speed holding operation cam 102
From the state of engaging with the claw portion 102a of the gear shift operation cam 1
Although it is possible to rotate the locking portion 109a of the gear 09 from the upper side to the lower side, the reverse is impossible, and the shift pedal 31
Is biased in the direction to release the foot, the locking portion 109a of the shift operation cam 109 is biased to rotate upward, and the shift operation cam 109, that is, the shift pedal 3
The operation position 1 can be held.

Next, the operation of the traveling speed holding mechanism having the above structure will be described.

First, the case of operating the traveling speed holding mechanism will be described. When operating from the state where the traveling speed holding mechanism is released, after depressing the speed change pedal 31 to obtain a desired vehicle speed, when the speed holding operation lever 54 is pulled to the front side, the speed change operation rod 50 is moved. By being pulled upward, the speed holding operation cam 102 rotates about the cam shaft 136, and the claw portion 102a of the speed holding operation cam 102 engages with the locking portion 109a of the speed change operation cam 109,
The operation position of the speed holding operation lever 54 is held even when the hand is released from the speed holding operation lever 54.

As described above, when the traveling speed holding mechanism operates, the upward rotation of the locking portion 109a of the speed change operation cam 109 is restricted, and the rotation of the speed change pedal 31 and the control shaft 108 is restricted. The angle of the swash plate 107 of the hydraulic pump 85 of the hydraulic continuously variable transmission 57 cannot be changed, and the traveling speed of the vehicle 1 is maintained.

The locking portion 109 of the shift operation cam 109
By forming a plurality of teeth on a, the gear shift operation cam 109 is within a certain range, that is, the locking portion 10
Within the engagement range of 9a and the claw portion 102a, the operating position can be held so that a wide shift range can be accommodated.

Next, the case where the traveling speed holding mechanism is released will be described. When the traveling speed holding mechanism is operating, the operating position of the speed holding operating lever 54 is held in a state of being pulled to the front side. Then, when the speed maintaining operation lever 54 is rotated in the forward tilting direction, the operation rod 50 is pushed out via the lever arm 54a, and the speed maintaining operation cam 102 pivotally connected to the lower end of the operation rod 50. Rotates about the cam shaft 136, and the locking portion 109a of the speed change operation cam 109 and the speed holding operation cam 1
02, the engagement of the claw portion 102a is released, the shift operation cam 109 becomes rotatable, the operation position of the shift pedal 31 is not held, and the shift operation is possible, that is, the traveling of the vehicle 1. The speed is not held.

The traveling speed holding mechanism can also be released by depressing the brake pedal 30. A speed holding operation cam 102 is connected to the brake pedal 30 via an interlocking plate 129, and the speed holding operation cam 1 is interlocked with the stepping operation of the brake pedal 30.
02 rotates in a direction to release the engagement with the shift operation cam 109. Then, the shift operation cam 109 becomes rotatable, the operation position of the shift pedal 31 is not held, and the shift operation is possible, that is, the traveling speed of the vehicle 1 is not held.

As described above, when the brake pedal 30 is depressed, the main clutch 47 is disengaged and the brake device 120 acts on the front output shaft 92 to cause the front wheels 6 to operate.
-The brake is applied to 6 and the vehicle 1 is braked. At this time, unless the shift pedal 31 is stepped on, the shift operation cam 109 does not rotate in the direction of increasing the vehicle speed and is not accelerated. Therefore, even though the brake pedal 30 is depressed to reduce the vehicle speed, the vehicle speed is not accelerated unintentionally.

Further, by depressing the transmission pedal 31, the traveling speed holding mechanism can be released. As described above, the locking portion 109a of the shift operation cam 109
Since the locking portion 109a of the speed change operation cam 109 can rotate downward when the claw portion 102a of the speed hold operation cam 102 is engaged with the speed change operation cam 102,
9 and the speed holding operation cam 102 are engaged, that is, when the operation position of the speed change pedal 31 is held, when the speed change pedal 31 is further depressed, the speed change operation cam 109 rotates and the speed change operation cam The engagement portion 109a of the gear 109 and the claw portion 102a of the speed holding operation cam 102 are disengaged from each other, and the speed change operation cam 109 becomes rotatable, and the operation position of the speed change pedal 31 is not held and the speed change operation is performed. Is enabled, that is, the traveling speed of the vehicle 1 is not maintained.

As described above, in the traveling speed holding mechanism according to the present invention, the gear shifting operation cam 1 is used as a mechanism for holding the speed change pedal 31 at a constant operation position and holding the traveling speed of the vehicle 1.
09 and the locking portion 10 formed on the shift operation cam 109
9a, a speed holding operation cam 102 having a claw portion 102a that engages with the running speed holding mechanism, and the running speed holding mechanism can be switched to a holding or non-holding (operating or releasing) state.
The brake pedal 3 serves as a switching unit that can switch the speed holding operation lever 54 to the non-holding state of the traveling speed holding mechanism.
0 and a shift pedal 31 are provided.

Therefore, if the traveling speed retaining mechanism is released by the speed retaining operation lever 54, the releasing operation can be performed without depressing the pedals such as the speed change pedal 31 and the brake pedal 30, that is, the traveling vehicle 1 is decelerated and stopped. It can be operated by the operator's hand. Particularly in rice transplanters and the like, when traveling while maintaining the vehicle speed by operating the traveling speed holding mechanism, it is common to steer the vehicle with the foot removed from the pedal. If it can be canceled only by operation, it is inconvenient to move the foot to the position of the pedal when trying to stop the traveling of the vehicle, but it is inconvenient because the speed holding mechanism can be released by manual operation. Can be eliminated and operability is improved.

Further, since the traveling speed holding mechanism can be released by any of the speed holding lever 54, the brake pedal 30, and the speed change pedal 31, it can be operated by either the hand or the foot depending on the preference of the operator. You can choose to do so.

[0067]

Since the present invention is constructed as described above,
The following effects are achieved.

That is, as described in claim 1, in a traveling vehicle provided with a holding mechanism for holding the speed change pedal at a constant operating position, an operating lever is provided for switching the holding mechanism to a holding or non-holding state. It is possible to release the holding mechanism by a manual operation without depressing the pedal to bring the operation position of the shift pedal into a non-holding state.

According to a second aspect of the present invention, in the traveling speed holding mechanism according to the first aspect, the holding mechanism includes a gear shift operation member having a pawl portion provided on the side of the speed change pedal, and a member that engages the pawl portion. Since the holding operation member is provided with a joint portion, and the holding operation member and the operation means are connected by an elastically deformable member, erroneous operation of the shift pedal or abnormal engagement between the shift operation member and the holding operation member is prevented. Even if it occurs, damage to the pedal or lever can be prevented.

[Brief description of drawings]

FIG. 1 is a plan view showing the overall structure of a rice transplanter according to this embodiment.

FIG. 2 is a side view of the same.

FIG. 3 is a plan view showing a body frame.

FIG. 4 is an explanatory side view of a driving unit.

FIG. 5 is an explanatory plan view of a drive unit.

FIG. 6 is a sectional view of a mission case.

FIG. 7 is a skeleton diagram of a mission case.

FIG. 8 is an explanatory diagram of a main clutch.

FIG. 9 is an explanatory diagram of a brake device.

FIG. 10 is an explanatory diagram of a PTO transmission mechanism.

FIG. 11 is a right side view showing the speed holding mechanism.

FIG. 12 is a perspective view showing a brake pedal and a shift pedal.

FIG. 13 is a right side view of the same.

FIG. 14 is a plan view of the same.

FIG. 15 is a left side view showing a shift pedal.

FIG. 16 is a perspective view showing a pedal support portion of a vehicle body frame.

FIG. 17 is a left side view showing a brake pedal.

FIG. 18 is a perspective view of the same.

FIG. 19 is a perspective view showing a holding operation lever.

[Explanation of symbols]

1 traveling vehicle 30 brake pedal 31 speed change pedal 50 Operation rod 54 Speed holding lever 102 Speed holding operation cam 102a claw 109 gear change operation cam 109a locking part

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) B60K 20/00 B60K 20/00 D 3D044 25/06 25/06 31/00 31/00 Z // E02F 9 / 20 E02F 9/20 FF term (reference) 2B062 AA04 BA22 BA23 2B076 AA03 CD03 DA02 DA15 DC02 2D003 AB01 AC01 BA02 CA02 DA01 3D037 CA03 CB12 3D040 AA31 AB04 AC50 AC60 3D044 AA01 AA21 AA50 AB41 AD01 AC26 AC26 AC16 AC16

Claims (2)

[Claims] 1. A traveling vehicle provided with a holding mechanism for holding a speed change pedal at a constant operation position, characterized in that an operating lever capable of switching the holding mechanism to a holding or non-holding state is provided. mechanism. 2. The traveling speed holding mechanism according to claim 1, wherein the holding mechanism includes a gear shift operation member having a claw portion provided on the speed change pedal side, and an engagement portion engaging with the claw portion. A traveling speed holding mechanism comprising a holding operation member, wherein the holding operation member and the operating means are connected by an elastically deformable member.