JP4575815B2 - Working vehicle - Google Patents

Description

  The present invention relates to a work vehicle such as a passenger rice transplanter.

2. Description of the Related Art A working vehicle that travels according to driving of front wheels and rear wheels and turns according to steering of front wheels is known. In this type of work vehicle, various mechanisms for changing the transmission state of the front wheels and the rear wheels in conjunction with the steering of the front wheels have been proposed in order to improve the turning performance in Fukada and the like (Patent Document 1). 2). For example, the riding work machine described in Patent Document 1 includes a turning differential lock mechanism that forcibly creates a rotational difference between the left and right front wheels in conjunction with the steering of the front wheels. The paddy field work vehicle includes a link mechanism that disconnects the rear wheel side clutch inside the turn in conjunction with the steering of the front wheels.
JP-A-9-58517 JP 2004-268853 A

  However, in the riding work machine described in Patent Document 1, it is necessary to disengage the rear wheel side clutch inside the turn when turning the airframe, and thus the operation during turning is complicated. On the other hand, in the paddy field vehicle described in Patent Document 2, the side clutch operation during turning is automatically performed, but not only the front wheel may slip, but also the front wheel diff lock operation is required when the front wheel slips. There is a problem.

The present invention was created for the purpose of solving these problems in view of the circumstances as described above, and includes a transmission case for inputting engine power, traveling according to the driving of the front wheels and the rear wheels, In a working vehicle in which a pitman arm that rotates left and right according to the operation of the steering wheel to steer the left and right front wheels is arranged below the bottom of the transmission case, the rear wheels inside the turn are linked to the steering of the front wheels. In conjunction with the rear wheel interlock mechanism that cuts off the transmission to the front wheel, the front wheel on the outside of the turn is accelerated more than the rear wheel on the outside of the turn, and the front wheel on the inside of the turn is decelerated more than the front wheel on the outside of the turn and a front wheel interlocking mechanism for, the front wheel interlocking mechanism configured inside the transmission case, constitute the rear wheel interlocking mechanism to the outside of the transmission case, with the steering of the front wheel When the rear wheel speed reduction mechanism for decelerating the rear wheel power is provided, the rear wheel interlocking mechanism is extended from the bottom of the bottom of the transmission case to the rear from the pitman arm to rotate the pitman arm. A pair of left and right first rods pushed and pulled in response to each other, a pair of left and right arm support shafts disposed behind the transmission case, and extending downward from each arm support shaft. A first arm connected to one rod, a second arm extending upward from each arm support shaft and connected to each side clutch mechanism via a second rod respectively facing in the front-rear direction, and each arm support A working vehicle characterized by comprising a third arm extending upward from the shaft and linked to the rear wheel speed reduction mechanism via a third rod that faces in the front-rear direction . In this way, it is possible to smoothly turn the airframe while suppressing the slip of the front wheels only by turning the steering wheel without performing the side clutch operation. In addition, on the rear wheel side, the side clutch inside the turn is disengaged, and on the front wheel side, a turning pattern that forcibly creates a rotation difference between the left and right front wheels enables a smooth small turn without roughening the surface. In addition , since mutual interference is avoided, the front wheel interlocking mechanism and the rear wheel interlocking mechanism can be easily arranged, and the turning of the rear wheel not only enables small turning, but also reduces the traveling load. Engine drop during turning can also be prevented.

  Next, embodiments of the present invention will be described with reference to the drawings. In FIG. 1, reference numeral 1 denotes a riding rice transplanter. The riding rice transplanter 1 includes a traveling machine body 2, a planting part 4 connected to a rear part of the traveling machine body 2 via an elevating link mechanism 3, and the planting machine 1. The ground leveling rotor 5 provided in the front side of the attaching part 4 is provided.

  The traveling machine body 2 includes an engine 6 mounted on the front part of the machine body, a belt-type continuously variable transmission 7 that continuously changes engine power, and a transmission case 8 that inputs engine power via the continuously variable transmission 7. Is provided. The mission case 8 enters / disconnects the input power by the main clutch mechanism 9 and branches into planting power and work power downstream of the transmission of the main clutch mechanism 9. The branched planting power is output from the planting PTO shaft 12 via the inter-plant transmission mechanism 10 and the planting clutch mechanism 11, and is transmitted to the planting unit 4 from here.

  The traveling power is shifted by the auxiliary transmission mechanism 13 and branched into front wheel power and rear wheel power at a traveling transmission shaft 14 downstream of the transmission. The front wheel power is distributed to the left and right differential output shafts 16L and 16R via a differential mechanism (differential mechanism) 15, and is transmitted from here to the left and right front wheels 17. A turning differential lock mechanism 18 is configured between the travel transmission shaft 14 and the right differential output shaft 16R. The turning differential lock mechanism 18 is supported by the right differential output shaft 16R so as to be freely rotatable at a predetermined interval, and is always paired with the transmission gears 19 and 20 on the traveling transmission shaft 14 side. The transmission gears 21, 22 and the turning transmission gears 21, 22 are spline-fitted to the right differential output shaft 16R, and the left and right sides are connected to the engaging claws 21a, 22a of the turning transmission gears 21, 22 The clutch body 23 is provided with a meshing claw 23a that can be selectively meshed.

  The rotation transmitted to one turning transmission gear 21 is set at a higher speed than the input rotation of the differential mechanism 15, and the rotation transmitted to the other turning transmission gear 22 is set from the input rotation of the differential mechanism 15. Is also set to low speed. That is, the turning differential lock mechanism 18 is configured to forcibly increase / decrease the rotation of the right differential output shaft 16R based on the selective engagement operation of the clutch body 23 with respect to the pair of turning transmission gears 21, 22. Has been. When the speed of the right differential output shaft 16R is increased, the left differential output shaft 16L is decelerated based on the action of the differential mechanism 15. Therefore, the left differential output shafts 16L and 16R are turned to the left. A constant rotation difference suitable for the above can be forcibly generated, and when the right differential output shaft 16R is decelerated, the left differential output shaft 16L is conversely increased, so the difference between the left and right A certain rotation difference suitable for right turn can be forcibly generated between the dynamic output shafts 16L and 16R.

  On the other hand, the rear wheel power is output from the traveling PTO shaft 24 and transmitted to the rear axle case 26 via the rear wheel speed reduction mechanism 25. The rear wheel speed reduction mechanism 25 includes a normal transmission path 25a, a deceleration transmission path 25b, and a friction clutch 25c that selectively enters one of the transmission paths 25a and 25b. The rear wheel power is decelerated in accordance with the operation 25d.

  The rear axle case 26 includes a distribution shaft 27 that distributes the rear wheel power input from the rear wheel speed reduction mechanism 25 to the left and right, a pair of left and right side clutch mechanisms 28L and 28R provided on both left and right sides of the distribution shaft 27, and the side clutch mechanism. The rear wheel power is transmitted to the left and right rear wheels 30 via a pair of left and right side brake mechanisms 29L and 29R provided on the transmission downstream side of 28L and 28R. The side clutch mechanisms 28L and 28R are selectively turned off when turning the aircraft and cut off the transmission to the rear wheel 30 inside the turn, thereby enabling the vehicle to turn around. The side brake mechanisms 29L and 29R are turned on and off simultaneously when the aircraft is stopped. Thus, the left and right rear wheels 30 can be reliably braked even while the aircraft is turning (side clutch disengaged).

  The side clutch mechanisms 28L and 28R are turned off by a pair of left and right clutch arms 31L and 31R provided at the upper part of the rear axle case 26, and the side brake mechanisms 29L and 29R are provided as a pair of left and right clutches provided at the front part of the rear axle case 26. Are operated by the brake arms 32L and 32R. The left and right brake arms 32L and 32R are connected to each other via a rod 33, and are connected to a clutch / brake pedal 36 via a link arm 34 and a rod 35. When the clutch / brake pedal 36 is depressed, the main clutch arm 38 connected via the rod 37 is pulled, and the main clutch mechanism 9 is turned off before the left and right side brake mechanisms 29L and 29R are engaged. become.

A pitman arm 39 is provided below the bottom of the mission case 8. The pitman arm 39 is linked to the steering wheel 40 and the front wheel 17 so as to rotate left and right in accordance with the operation of the steering wheel 40 and to steer the left and right front wheels 17. The pitman arm 39 is connected to a front wheel interlocking mechanism 41 and a rear wheel interlocking mechanism 42. The front wheel interlocking mechanism 41 interlocks the turning differential lock mechanism 18 with the rotation of the pitman arm 39, and the rear wheel interlocking mechanism 42 interlocks the left and right side clutch mechanisms 28L, 28R with the rotation of the pitman arm 39. Thus, in conjunction with the steering of the front wheel 17, the transmission to the rear wheel 30 inside the turn is cut off, the front wheel 17 outside the turn is accelerated more than the rear wheel 30 outside the turn, and the front wheel 17 inside the turn is It becomes possible to decelerate from the front wheel 17 outside the turn . If comprised in this way, it will become possible to turn a body smoothly, suppressing the slip of the front wheel 17, only by turning operation of the steering wheel 40, without performing side clutch operation.

  In addition, the side clutch mechanisms 28L and 28R inside the turn are turned off on the rear wheel 30 side, and the surface is roughened by an interlocking pattern during turning that forcibly creates a rotational difference between the left and right front wheels 17 on the front wheel 17 side. No smooth turn is possible. That is, if the vehicle is simply turned, the rear wheel 30 on the inside of the turn may be braked by the side brake mechanisms 29L and 29R. However, since the surface becomes rough, only the side clutch mechanisms 28L and 28R are turned off on the rear wheel 30 side. I do. However, if only the side clutch mechanisms 28L and 28R are turned off on the rear wheel 30 side and the front wheel 17 side is driven by the differential mechanism 15, the turning radius becomes large due to slip of the front wheel 17 and accompanying rotation of the rear wheel 30 inside the turning. This makes it difficult to align after turning. Accordingly, in the present invention, a turning difference is forcibly generated between the left and right front wheels 17 to bring about a turning state in which the turning radius is not increased and the paddy surface is not roughened.

  Next, the front wheel interlocking mechanism 41 and the rear wheel interlocking mechanism 42 will be described in detail. The front wheel interlocking mechanism 41 is housed in the transmission case 8, and includes a shift fork 43 engaged with the clutch body 23, a slidable shift shaft 44 integrally including the shift fork 43, and a slide of the shift shaft 44. The shift lever 45 and the interlocking plate 47 that interlocks the shift lever 45 with the support shaft 46 of the pitman arm 39 are configured to turn by the switching operation of the turning differential lock mechanism 18 according to the rotation of the pitman arm 39. A rotation difference suitable for the direction is forcibly generated between the left and right front wheels 17.

On the other hand, the rear wheel interlocking mechanism 42 is configured outside the mission case 8. Thereby, interference with the front wheel interlocking mechanism 41 configured inside the mission case 8 is avoided, and the arrangement of the front wheel interlocking mechanism 41 and the rear wheel interlocking mechanism 42 is facilitated. More specifically, the rear wheel interlocking mechanism 42 extends from the bottom bottom of the transmission case 8 to the rear, and is paired with a pair of left and right first rods 48L that are pushed back and forth as the pitman arm 39 rotates. , 48R, a pair of left and right arm support shafts 49L, 49R arranged behind the transmission case 8 , and a first arm 50L extending downward from the arm support shafts 49L, 49R and connected to the rods 48L, 48R, 50R and second arms 52L and 52R that extend upward from the respective arm support shafts 49L and 49R and are connected to the clutch arms 31L and 31R via the second rods 51L and 51R facing the front-rear direction, respectively. Then, by selectively turning the side clutch mechanisms 28L and 28R according to the rotation of the pitman arm 39, transmission to the rear wheel 30 inside the turn Sever. The traveling machine body 2 of the present embodiment has a rear wheel interlock release pedal 53. When the rear wheel interlock release pedal 53 is depressed, the first arms 50L and 50R are pushed back to the front clutch mechanism 28L. , 28R is released.

Further, the rear wheel interlocking mechanism 42 of the present embodiment extends upward from the arm support shafts 49L and 49R, and is connected to the rear wheel deceleration arm 25d via the third rods 54L and 54R, respectively . 55R is further provided. In this way, the rear wheel power is automatically decelerated in conjunction with the steering of the front wheels 17, so that not only the turning radius becomes smaller, but also the traveling load is reduced and engine drop during turning can be prevented. .

  According to the present embodiment configured as described, the vehicle travels according to the driving of the front wheels 17 and the rear wheels 30, and turns according to the steering of the front wheels 17, but in conjunction with the steering of the front wheels 17, In conjunction with the rear wheel interlock mechanism 42 that cuts off the transmission to the rear wheel 30 and the steering of the front wheel 17, the front wheel 17 on the outer side of the turn is accelerated more than the rear wheel 30 on the outer side of the turn, and the front wheel 17 on the inner side of the turn Since the front wheel interlocking mechanism 41 for decelerating is provided, it is possible to smoothly turn the airframe while suppressing the slip of the front wheel 17 only by turning the steering wheel 40 without performing the side clutch operation. In addition, the side clutch mechanisms 28L and 28R inside the turn are turned off on the rear wheel 30 side, and the surface is roughened by an interlocking pattern during turning that forcibly creates a rotational difference between the left and right front wheels 17 on the front wheel 17 side. No smooth turn is possible.

  Further, since the front wheel interlocking mechanism 41 is configured inside the mission case 8 and the rear wheel interlocking mechanism 42 is configured outside the mission case 8, mutual interference is avoided, and the front wheel interlocking mechanism 41 and the rear wheel interlocking mechanism are avoided. Arrangement of the interlocking mechanism 42 is facilitated.

  In addition, since the rear wheel speed reduction mechanism 25 that decelerates the rear wheel power in conjunction with the steering of the front wheel 17 is provided, not only turning by turning the rear wheel 30 is possible, but also turning while reducing the traveling load. The engine drop can be prevented.

It is a side view of a riding rice transplanter. It is a transmission circuit diagram of a riding rice transplanter. It is a principal part top view of a traveling body. It is a principal part side view of a traveling body. It is a side view of the front wheel interlocking mechanism and the turning differential lock mechanism. It is a top view of the interlocking mechanism for front wheels and the differential lock mechanism for turning. It is a front view of a turning differential lock mechanism. It is a side view which shows the interlocking mechanism for rear wheels and the clutch / brake pedal interlocking mechanism. It is a top view of the interlocking mechanism for rear wheels. It is a side view of the interlocking mechanism for rear wheels. It is a side view which shows a rear-wheel deceleration interlocking mechanism.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Riding rice transplanter 2 Traveling machine body 6 Engine 8 Transmission case 15 Differential mechanism 17 Front wheel 18 Turning differential lock mechanism 25 Rear wheel speed reduction mechanism 26 Rear axle case 28 Side clutch mechanism 29 Side brake mechanism 30 Rear wheel 39 Pitman arm 40 Steering wheel 41 Front wheel Interlock mechanism 42 Rear wheel interlock mechanism

Claims (1)

A pitman arm that has a transmission case for inputting engine power, travels according to the driving of the front wheels and rear wheels, and rotates left and right according to the operation of the steering wheel to steer the left and right front wheels. In the work vehicle that is arranged, the rear wheel interlocking mechanism that cuts off the transmission to the rear wheel inside the turn in conjunction with the steering of the front wheel, and the front wheel on the outside of the turn on the outside of the turn in conjunction with the steering of the front wheel. A front wheel interlocking mechanism that increases the speed of the rear wheel and decelerates the front wheel on the inside of the turn more slowly than the front wheel on the outside of the turn, and the front wheel interlocking mechanism is configured inside the transmission case, and the rear wheel interlocking When the mechanism is configured outside the transmission case and includes a rear wheel speed reduction mechanism that decelerates rear wheel power in conjunction with the steering of the front wheel, the rear wheel interlock mechanism is A pair of left and right first rods that extend from the lower part of the bottom of the transmission case to the rear side of the transmission case and are pushed and pulled in accordance with the rotation of the pitman arm, and are positioned behind the transmission case. A pair of left and right arm support shafts, a first arm extending downward from each arm support shaft and connected to the first rod, and a second arm extending upward from each arm support shaft and facing in the front-rear direction A second arm linked to each side clutch mechanism via a rod, and a third arm linked to the rear wheel speed reduction mechanism via a third rod extending upward from each arm spindle and facing in the front-rear direction. working vehicle, characterized by being configured with and.

Images