JPH07112784B2 - Work vehicle equipped with hydraulic continuously variable transmission - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a work vehicle in which an engine is mounted on a front portion of a vehicle body and a hydraulic continuously variable transmission is mounted on a rear portion of the vehicle body.

(Prior Art) Work vehicles typified by riding lawn mowers have become popular because they are capable of automating and mass-processing lawn mowing work that has been performed manually.

An example of this type of work vehicle is shown in U.S. Pat. Is located on the lower right side of the handle.

(Problems to be Solved by the Invention) However, since the foot pedal and the hydraulic continuously variable transmission disposed below the seat are disposed far apart from each other, the link member connecting them is long and complicated.

Further, when the engine is mounted on the front part of the vehicle body, the transmission member that connects the engine output shaft and the hydraulic transmission input shaft becomes large, and the vehicle body is longitudinally cut together with the link member for gear shifting. Not only does the lower structure become complicated and the design of the vehicle body becomes difficult, but maintenance, inspection, and replacement of consumables become troublesome.

(Means for Solving the Problem) In order to solve the above-mentioned inconvenience, the present invention directly connects an engine and a hydraulic continuously variable transmission with one universal shaft or one endless V-belt via a pulley. In addition, the main purpose is to dispose a speed change lever that the occupant grips on the right or left of the seat, and in order to achieve this, in the hydraulic continuously variable transmission of the work vehicle, the input shaft is projected to the center of the front part, With this input shaft as a reference, the shift control shaft of the hydraulic continuously variable transmission is erected on one side in the vehicle width direction, and the shift lever that the occupant grips is positioned on the other side with its swing center near the input shaft. Then, the gear shift control shaft and the gear shift lever are connected by a link member, and the link member is arranged above the housing of the hydraulic continuously variable transmission.

In addition, in conjunction with the brake pedal, when the brake pedal is stepped on, the shift control shaft is rotated to forcibly return the hydraulic continuously variable transmission to the neutral state.
It is placed above the housing of the hydraulic continuously variable transmission and is rotatably attached to the housing.

The link member is composed of an arm plate having one end coupled to the shift control shaft and extending in the vehicle width direction, and a short tie rod engaging with the tip of the arm plate and extending forward. Engages with the shift lever base member.

Further, the gear shift lever base member includes a pipe portion swingably locked to the vehicle body, a gear shift lever engaging plate fixed to one end of the pipe portion, and a swing lever fixed to the other end of the pipe portion. The rocking lever, the pipe portion, and the operating lever engaging plate form a letter-shaped member, and the deck support arm can be freely moved in and out of the letter-shaped member.

(Operation) The occupant of the work vehicle operates the speed change lever with one hand to change the vehicle speed and selects the forward / reverse mode. At this time, since the speed change lever and the hydraulic continuously variable transmission are connected by a very short link member, the response of the hydraulic continuously variable transmission to the speed change lever is good.

In addition, the link member and the return arm are arranged on the upper part of the housing of the hydraulic continuously variable transmission to effectively utilize the space above the housing. Further, the return arm is pivotally supported directly on the housing.

Further, the link member is accommodated in a narrow space by inserting the deck support arm into the character-shaped inside of the gear shift lever base member.

(Example) The Example of this invention is described below based on an accompanying drawing.

FIG. 1 is a side view of a work vehicle according to the present invention. The work vehicle 1 includes an engine 3 and front wheels 4, on a front portion of a body frame 2.
4, the handle 5 and the cutter deck 6 are arranged in the center, the seat 7 and the rear wheels 8, 8 are arranged in the rear part, the engine 3 is surrounded by the bonnet 9, and the cutter deck 6 houses the lawn mowing blade 10, A hydraulic continuously variable transmission 20 is provided between the rear wheels 8, 8.

This hydraulic continuously variable transmission 20 has a propeller shaft 12 attached to the engine 3.
It is directly connected with.

Although not shown, when the engine 3 is a vertical engine, the crankshaft hangs down from the bottom of the engine 3, a pulley is attached to this shaft, and the center of the front part of the hydraulic continuously variable transmission 20 mounted on the rear side. It is also conceivable that the input shaft hangs downward, a pulley is attached to this input shaft, and the above pulleys are interlocked and connected by a V-belt.

FIG. 2 is a plan view of the work vehicle. The brake pedal 40 projects to the right step 13 on the right front side of the seat, the shift lever 50 projects to the right side of the seat 7 (above the drawing) through the fender 14, and A deck lifting lever 60 projects through the fender 14 to the left of the seat (downward in the drawing).

FIG. 3 is a sectional view taken along the line AA of FIG. 1, and the speed change lever 50 is connected to the speed change control shaft 21 of the hydraulic continuously variable transmission 20 via a link member 51 which will be described in detail later. This shift control axis
As shown in the drawing, 21 is characterized in that it stands up at a position that is sufficiently distant from the speed change lever 50 with respect to the input shaft 22 of the hydraulic continuously variable transmission positioned substantially in the vehicle width direction.

FIG. 4 is a developed sectional view of the hydraulic continuously variable transmission.

The hydraulic continuously variable transmission 20 forms a container by closing the illustrated left part of the case 23 with a substrate 24, projects the input shaft 22 forward from the case 23, and a pump shaft 25a that is connected to the input shaft by a bevel gear, A motor shaft 26a arranged in parallel with the pump shaft, an intermediate shaft 27 gear-coupled to the motor shaft, a differential mechanism 28 gear-coupled to the intermediate shaft, and rear axles 29, 29 extending from the differential mechanism. Is a so-called differential axial piston type transmission.

Therefore, the pump shaft 25a penetrates the pump case 25d that surrounds the pistons 25b ... and the speed change swash plate 25c, and the motor shaft 26a penetrates the motor case 26d that surrounds the pistons 26b ... and the swash plate 26c.

In the figure, 25e is a shaft of a swash plate of a pump, 30 is a common cover that also serves as a charge pump case, 31 is a brake that appropriately brakes a shoe by contacting a drum 31a at a motor shaft end, and 31b. Is a brake arm.

FIG. 5 is a plan view of the hydraulic continuously variable transmission, in which the speed change control shaft 21 connected to the speed change swash plate shaft stands upright and a boomerang-shaped arm plate 52 is fastened to the shaft 21. The input shaft 22 extends from the left to the right. This arm plate 52
Two guide holes 52a and 52b are formed in the hole. 3 in the figure
2 is a nylon reserve oil tank, and 32a is the inlet cap.

FIG. 6 is a view taken along the line BB of FIG.
A return arm 53 is arranged below 52. The return arm is supported by a bracket fixed to the case 23 of the hydraulic continuously variable transmission so as to be horizontally rotatable about a shaft 53c. Two pins 53a and 53b are provided on the return arm 53 so as to project, and these are guide holes 52 of the arm plate.
It penetrates to a and 52b respectively. The tip of the return arm is operated by the brake pedal 40.

FIG. 7 is a perspective view showing a link member related to the speed change lever. The link member 51 is composed of the boomerang-shaped arm plate 52 and tie rods 55 having ball joints at both ends, and supports the base portion 50a of the speed change lever 50. It is connected to the shift lever base member 54.

The gear shift lever base member 54 is a member formed by a groove-shaped gear shift lever engaging plate 54a, a pipe portion 54b, and a swing lever 54c, and is housed in a bracket 2a fixed to the body frame 2 in a plan view. Shaft 54d having a bolt portion and a spline portion at one end, and a spring pin p1, a thrust washer p2, a spring guide p3, a spring p4, two shims p5, p5, a spring receiver p6 attached to this shaft.
The friction washer p7, the disk p8, and the nut p9 are swingably locked. The base portion 50a of the shift lever 50 is locked by a pin 54e in the groove portion of the shift lever engaging plate 54a.
The speed change lever 50 can be swung in the direction of the arrow, and the spring 54
It is urged to the outside of the guide plate 54g at f.

On the other hand, the tip of the tie rod 55 is engaged with the upper end of the swing lever 54c.

As a result, as shown in FIG. 5, the swing center of the shift lever 50 in the longitudinal direction of the vehicle body, that is, the pipe portion 54b is arranged immediately to the right of the hydraulic continuously variable transmission 20. Since the pipe portion 54b does not come to the front of the front end portion of the input shaft 22 of the hydraulic continuously variable transmission 20, the tie rod 55 can be formed extremely short.

FIG. 8 is a view showing a vehicle braking member, which is a brake pedal.
40 is supported by the bracket 2b and the pin 41 on the body frame 2, and is urged in the clockwise direction in the figure by a spring 42 which is also locked at one end on the body frame.

The vehicle braking member includes the brake pedal 40 and a first rod 43 connected to the brake pedal and extending in the vehicle length direction.
And a relay lever 44 that is engaged with the first rod and is locked to the vehicle body frame by a pin 44a, and connects the relay lever 44 and the return arm 53 of the hydraulic continuously variable transmission (see FIG. 6). A second rod 46 which is connected to the brake pedal 40, and a third rod which is connected to the brake pedal arm through a lost motion hole 40b and extends in the longitudinal direction of the vehicle.
45a, a damper 45b located between the third rod 45a, and a pin 45 attached to the body frame while engaging with the third rod.
The relay arm 45d locked by c and this relay arm 45
The fourth rod 4 connecting d with a brake arm 31b (see FIG. 4) for braking the motor output shaft 26a of the hot water continuously variable transmission
It consists of 5e.

Therefore, when the brake pedal 40 is depressed and rotated in the direction of the arrow, the brake pedal 40a rotates left, the first rod 43 moves forward, the relay lever 44 rotates left, the second rod 46 moves forward, and the return arm 53 moves. The hydraulic continuously variable transmission 20 is approximated to the neutral state as described later in detail.

Next, the brake pedal arm 40a advances the third rod 45a, rotates the relay arm 45d clockwise, and rotates the brake arm 31b clockwise through the fourth rod 45e to perform a braking action. The damper 45b absorbs the shock during this period.

FIG. 9 is a view showing the deck elevating member. The cutter deck 6 for housing the lawn mowing blade has its front edge engaged with the vehicle body frame 2 via the front levers 61, 61, and the rear edge of the cutter deck 6 is It is supported by rear levers 62,62. The front edges of the rear levers 62, 62 are pin-locked to the vehicle body frame 2, the middle long hole 62a is pin-engaged with the deck rear edge, and the rear end of the rear lever is engaged with the vertical lever 63. .

The vertical lever 63 is pin-engaged with the right and left deck support arms 64, 65 extending horizontally through the upper end long hole 63a, and the deck support arms 64, 65
The base 65 is fixed to a horizontal pipe 66 whose base extends over the vehicle body frame 2 in the vehicle width direction.

A deck lifting lever 60 is fixed to one end of the horizontal pipe 66, and the deck lifting lever 60 has a push button 6 at its grip 60a.
0b is built in, and by pushing this push button 60b, the claw 60c meshing with the notch plate 67 can be made free.

When the deck elevating lever 60 is pulled up in the direction of the arrow, this acting force is transmitted in the order of horizontal pipe 66 → deck support arms 64,65 → vertical bars 63,63 → rear levers 62,62, so that the cutter deck 6 rises.

The operation of the work vehicle having the above structure will be described below.

In FIG. 1, an occupant sits on the seat 7 and operates a gear shift lever 50 on the right side of the seat to make a so-called change. That is,
The output of the engine 3 is input to the hydraulic continuously variable transmission 20 via the propeller shaft 12, and the input shaft 22 shown in FIG. 4 → pump shaft 25a →
The power is transmitted to the rear wheels 8, 8 in the order of the motor shaft 26a → the intermediate shaft 27 → the differential mechanism 28 → the rear axles 29,29.

At this time, the speed ratio between the pump shaft 25a and the motor shaft 26a is determined by the speed change swash plate.
This shift swash plate 2 is determined by the tilt angle of 25c.
The angle of 5c is adjusted by the shift lever 50 in the following manner.

When the gear shift lever 50 shown in FIG. 5 is tilted forward, the gear shift lever base member 54 at the lower portion of the gear shift lever is also tilted forward, which causes the tie rod 55 to move forward, thereby allowing the gear shift control shaft 21 to move through the boomerang-shaped arm plate 52. The figure is rotated counterclockwise, and the transmission swash plate 25c is tilted accordingly. Similarly, when the gear shift lever 50 is tilted rearward, the arm plate 52 rotates rightward to position the gear shift swash plate 25c at the neutral and retracted positions.

On the other hand, when the brake pedal 40 shown in FIG. 8 is depressed, the second rod 46 causes the return arm 53 to rotate.

FIGS. 10 (a) and 10 (b) are neutral return operation diagrams, and in FIG. 10 (a), the arm plate 52 at the forward position is shown.
Against the return arm 53 pulled by the second rod 46
Rotates left about the axis 53c and causes the pin 53a to act on the guide hole 52a of the arm plate, and as a result, the arm plate 52 is forcibly moved to the position indicated by the imaginary line D1. Imaginary line D1 is a swash plate
Matches the neutral position of 25c.

Therefore, by stepping on the brake pedal 40, the hydraulic continuously variable transmission
20 is forcibly returned to the neutral state, and the brake arm 31b is swung with a slight delay to give a braking action.

FIG. 10 (b) shows the arm plate 52 at the position for retracting the vehicle.
, The return arm 53 rotates counterclockwise and its pin 53b
To the guide hole 52b of the arm plate,
Forcibly move it to the position indicated by imaginary line D2,
Return 25c to neutral position.

As described above, the occupant operates the speed change lever 50 with the right hand,
Operate the work vehicle 1 while operating the deck lift lever 60 with the left hand and depressing the brake pedal 40 with the right foot.

In this operation, the speed change lever 50 is located to the right of the seat 7, and the swing center of the speed change lever 50 is near the input shaft 22 of the hydraulic continuously variable transmission 20. The tie rods 55 that are very close to each other can be shortened, the response of the speed change lever 50 can be improved, and the link member 51 can be made compact.

Further, as shown in FIG. 3, the deck support arms 64 and 65 for raising and lowering the cutter deck are housed within the width of the vehicle body frames 2 and 2 below the seat 7 for convenience of arrangement. Since the deck support arms 64 and 65 not only extend in the front and rear direction but also swing up and down, it is necessary to secure a space for that purpose. In this embodiment, the right side deck support arm 64 is a rear-view-shaped shift lever base member. Since the 54-shaped member is passed through, the speed change link member 51 and the deck support arm 64 can be efficiently accommodated in the limited space.

Further, as shown in FIG. 5, the arm plate 52 is extended to the left and right around the input shaft 22 on the hydraulic continuously variable transmission 20 in a plan view, so that the lever lever 50 acts according to the lever principle. Reduce the required power.

Further, since the arm plate 52 is curved like a boomerang in a plan view, the reserve oil tank 32 can be arranged in the recess, and thus the space above the hydraulic continuously variable transmission 20 can be effectively utilized.

(Advantages of the Invention) As described above, according to the present invention, since the gear shift lever can be arranged in the immediate vicinity of the occupant to shorten the link member, the number of parts of the link member is reduced and the response of the gear shift lever is improved. Excuse me.

In addition, the link member and the return arm are arranged on the upper part of the housing of the hydraulic continuously variable transmission to effectively utilize the space above the housing. Further, the bracket can be omitted by pivotally supporting the return arm on the housing.

Further, since the deck support arm is mixed with the link member, the space around the hydraulic continuously variable transmission can be effectively used, and the vehicle body can be easily designed.

[Brief description of drawings]

 FIG. 1 is a side view of a work vehicle according to the present invention, FIG. 2 is a plan view of the work vehicle, FIG. 3 is a sectional view taken along line AA of FIG. 1, and FIG. 4 is a development of a hydraulic continuously variable transmission. Sectional view, FIG. 5 is a plan view of the hydraulic continuously variable transmission, FIG. 6 is a view taken along the line BB in FIG. 5, FIG. 7 is a view showing a gear shift lever link member, and FIG. 8 is vehicle braking. FIG. 9 is a diagram showing members, FIG. 9 is a diagram showing deck raising / lowering members, and FIGS. 10 (a) and 10 (b) are neutral return action diagrams. 1 …… Work vehicle, 3 …… Engine 8 …… Rear wheel, 20 …… Hydraulic continuously variable transmission 21 …… Shift braking shaft, 22 …… Input shaft 50 …… Shift lever, 51 …… Link member 52 …… Arm plate 54 ...... Gear shift lever base member 54a ...... Gear shift lever engaging plate 54b ...... Pipe portion, 54c ...... Swing lever 55 ...... Tie rod, 64 ...... Deck support arm

Claims (3)

[Claims] 1. A work vehicle in which an engine and a brake pedal are arranged in a front portion of a vehicle body, and a hydraulic continuously variable transmission for driving rear wheels is arranged in a rear portion of the vehicle body, wherein the hydraulic continuously variable transmission of the work vehicle is a front portion. The input shaft is projected from the center, and the transmission control shaft of the hydraulic continuously variable transmission is erected to one side in the vehicle width direction with reference to this input shaft, and the transmission lever held by the occupant is swung to the other side. Standing up with its center located rearward of the vicinity of the input shaft, connecting the speed change control shaft and the speed change lever with a link member, disposing the link member on the upper part of the housing of the hydraulic continuously variable transmission, and In conjunction with the pedal, when the brake pedal is stepped on, the shift control shaft is rotated to return the hydraulic continuously variable transmission to the neutral state forcibly.
A work vehicle equipped with a hydraulic continuously variable transmission, characterized in that the hydraulic continuously variable transmission is arranged at an upper portion of a housing of the hydraulic continuously variable transmission and is rotatably attached to the housing. 2. The link member comprises an arm plate having one end coupled to a shift control shaft and extending in the vehicle width direction, and a short tie rod engaging with the tip of the arm plate and extending forward, the tie rod tip portion. The work vehicle equipped with the hydraulic continuously variable transmission according to claim 1, wherein the gear is engaged with a gear shift lever base member below the gear shift lever. 3. A gear shift lever base member, a pipe portion swingably locked to a vehicle body, a gear shift lever engaging plate fixed to one end of the pipe portion, and fixed to the other end of the pipe portion. 3. A rocking lever, a rocking lever, a pipe portion, and an operating lever engaging plate to form a letter-shaped member, and a deck support arm can be freely moved in and out of the letter-shaped member. Work vehicle equipped with the hydraulic continuously variable transmission.