JPH09272359A - Transmission operating device for working vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify the structure and facilitate shift operation by changing a gear by an operation means having both functions of a shift operation means of a static hydraulic drive transmission and a shift operation means of a power take-out system. SOLUTION: In an ordinary working by a working vehicle, a shift lever 6 is pulled down vertically in a guide groove 8a so that a trunnion shaft 5 of a static hydraulic drive transmission is rotationally moved via a connecting link 22 and a lever 23 and the working vehicle is made to travel in the front/ rear direction by continuously variable speed in a low speed traveling range through the static hydraulic transmission 2. On the other hand, in traveling on road, a traction device 21 is released by stepping on a clutch pedal, the shift lever 6 is moved from the guide groove 8a side to a guide groove 8b side, and the working vehicle can advance at high speed by changing the gear to the high speed traveling range through a transmission of a power take-out system.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a speed change device for a work vehicle, which transmits power from a prime mover to two systems, a running system and a power take-off system, and which is provided with a hydrostatic drive system in the running system.

[0002]

2. Description of the Related Art Conventionally, in a working vehicle in which power from a prime mover is transmitted to two systems, a traveling system and a power take-out system, and the traveling system is equipped with a hydrostatic drive transmission, the hydrostatic drive transmission is used for the same traveling system. A gear shift operation device provided with a sub-transmission device separately from the device, wherein the low-speed side and the high-speed side are switched by the gear shift operation means of the sub-transmission device, and further, continuously variable shift travel is performed by the gear shift operation means of the hydrostatic drive transmission device. Is already known.

[0003]

DISCLOSURE OF THE INVENTION In the same traveling system as conventionally known, separately from the hydrostatic drive transmission,
The shift operating device is provided with an auxiliary transmission, and the low speed side and the high speed side are switched by the speed change operation means of the auxiliary speed change device, and further, the speed change operation means of the hydrostatic drive speed change device performs continuously variable speed travel. Two systems, a hydrostatic drive transmission and an auxiliary transmission, must be mounted, which is not only expensive, but also requires separate operating means, which complicates gear shifting operations. .

Therefore, the present invention transmits the power from the prime mover to the two systems of the traveling system and the power take-out system, and in the working vehicle equipped with the hydrostatic drive transmission in the traveling system, the power take-out already installed. It is an object of the present invention to simplify the structure and facilitate the gear shifting operation by using the system transmission so that both the low-speed traveling range and the high-speed traveling range can be operated by one operating means which is also used.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and transmits the power from a prime mover to two systems, a traveling system and a power take-out system, and a hydrostatic drive transmission system for the traveling system. In the working vehicle equipped with (2), the hydrostatic drive transmission (2) is used in the low speed traveling range, and the hydrostatic drive transmission (3) is switched in the high speed traveling range to the hydrostatic drive transmission. Device (2) and transmission device (3) for the power take-off system
The above-mentioned problem can be achieved by making it possible to switch to a switching operation to a switching operation means of the hydrostatic drive transmission (2) and a shifting operation means of the power take-off system (3) by a single operation means (6) that also serves as a switch. Solved.

(Operation) Based on the structure described above, the single operation means (6) having the dual function allows the static-hydraulic drive transmission (2) in the low-speed traveling range to continuously travel forward and backward and to move at high speed. When using the traveling range, the common gear shifting operation means (6)
When switching to the power take-off transmission (3), the power from the prime mover to the traveling system is cut off from the hydrostatic drive transmission (2) system, and the power take-off transmission (3).
Is switched to, and forward traveling is performed in the high-speed traveling range. again,
For use in a low speed traveling range, when the hydrostatic drive transmission (2) is switched by the one gear shifting operation means (6) which is also used, the power from the prime mover to the traveling system is the power of the power takeout system. After being disconnected from the transmission (3) system, it is possible to continuously travel forward and backward in the low speed traveling range via only the hydrostatic drive transmission (2) system.

[0007] The reference numerals in parentheses are for comparison with the drawings, but do not limit the configuration of the present invention.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

As shown in FIG. 1, the power from the prime mover of the work vehicle passes through the main clutch 1, the hydrostatic transmission 2 and the transmission 3 to drive the traveling wheels and the main clutch 1. And a power take-off system 2 for driving the PTO shaft 4 for taking out the power via the transmission 3
Transmitted to the grid.

The hydrostatic drive transmission 2 comprises a variable displacement hydraulic pump and a hydraulic motor connected in a closed circuit, and a transmission lever 6 connected to a trunnion shaft 5 for controlling the swash plate angle in the hydraulic pump. According to the dynamic angle, the traveling speed is continuously changed in the low-speed traveling range, and the shift lever 6 is tilted forward,
By tilting backward, the work vehicle can be moved forward and backward.

As shown in FIG. 2, the transmission 3 is located at the rear stage of the hydrostatic drive transmission 2 and is shifted in the hydrostatic drive transmission 2 from the input shaft 2a of the hydrostatic drive transmission 2. And a pinion shaft 3a coaxial with the first output shaft 2b and a gear 3b meshing with the pinion shaft 3a.
Power is received from a traveling system that drives traveling wheels via a second output shaft 2c that is coaxial with the input shaft 2a of the hydrostatic transmission 2, and the PTO transmission shaft 3c, the joint, and the PTO transmission gear train 3d. It is composed of two shafts and gears of a power take-out system for driving the PTO shaft 4 via the.

The lower front wheel drive shaft 3e is also driven from the PTO transmission shaft 3c via a gear provided on the pinion shaft 3a.

The speed change lever 6 is, as shown in FIG.
Located near the driver's seat above the transmission 3 and guided by the guide grooves 8a and 8b of the lever guide 8,
The work vehicle moves forward when tilted forward around a substantially neutral position, and moves backward when tilted backward, and continuously changes gears in the low-speed range depending on the tilt angle.

During normal work, it is sufficiently useful in the speed range of forward and reverse continuously variable shifts in the low speed traveling range obtained by the hydrostatic drive transmission 2, but in the high speed traveling range such as when traveling on the road, the static hydraulic pressure is used. The speed range of the drive transmission 2 is insufficient.

A transmission gear 10 is provided on the pinion shaft 3a in the transmission 3 and the pinion shaft 3a is provided.
When it is slid to the left and right on the spline and is on the left side, the first output shaft 2b and the pinion shaft 3a rotate integrally and share the speed range of forward and backward continuously variable transmission in the low speed traveling range,
When it is slid to the right and directly connected to the gear 11, the power of the first output shaft 2b is cut off, and the gear 1 of the PTO transmission shaft 3c is disconnected.
By directly driving the pinion shaft 3a from 2 through the gear 11, a constant high speed traveling range on the forward side can be obtained.

As shown in FIG. 3 (a), the lever guide 8 is provided with guide grooves 8a and 8b through which the speed change lever 6 is guided, and the upper side of the drawing shows the hydrostatic drive speed change device. 2 shows the guide groove 8a in the low speed traveling range, and the lower part of the drawing branching from the N (neutral) position shows the guide groove 8 in the high speed traveling range obtained from the power transmission system transmission 3.
b is shown. The left side of the figure shows the forward direction, and the right side shows the backward direction.

The lower part of the lever guide 8 is shown in FIG.
As shown in (a), (b), (c), the transmission gear 1
The shifter shaft 13 that slides 0 to the left and right in FIG. 2 extends outward from the case of the transmission 3, and the shifter shaft 13
A boss bracket 15 having a notch 15a that rotates integrally with the shifter shaft 13 from above and has a notch 15a that engages with the shift lever 6, and a boss 6 of the shift lever 6 that is loosely fitted to the shifter shaft 13.
a and a shifter shaft 13 are loosely fitted, and a boss bracket 17 having a notch 17a that engages with the speed change lever 6 is arranged in this order. As shown in FIG. 3C, a torsion spring 18 is provided on the support portion of the speed change lever 6, so that the speed change lever 6 always faces the center line of the width of the lever guide 8.
It is biased so as to be guided along the inside of the guide grooves 8a and 8b.

A mounting plate 20 is fixed to the central portion of the lower surface of the lever guide 8, and a spring 21 is attached to the mounting plate 20.
A restraint device 21 is supported which is movable back and forth against the biasing force of a. The rear end 21b of the restraint device 21 is shown in FIG.
As shown in (a), the N of the guide grooves 8a and 8b is always
Facing the (neutral) position, the shift lever 6 is prevented from moving between the guide grooves 8a and 8b.

The lower portion of the boss bracket 17 is interlocked with the trunnion shaft 5 via a connecting link 22 and a lever 23. When the gear shift lever 6 is tilted toward the guide groove 8a and moved back and forth, the boss bracket 17 is cut off. By engaging with the notch 17a, the work vehicle can be continuously and continuously traveled in the low speed traveling range through the hydrostatic drive transmission 2.

On the other hand, the tip of the restraint device 21 is interlockingly connected to the clutch shifter shaft 27 of the main clutch 1 via a connecting link 24 and a lever 25, and the clutch shifter shaft 2
Since 7 is directly connected to the clutch pedal 28, when the clutch pedal 28 is stepped on, the main clutch 1 is disconnected, and at the same time, the rear end 21b of the restraint device 21 is connected to the spring 21.
It moves forward against the biasing force of a, the draft production is released, and the speed change lever 6 can be tilted to the guide groove 8b side. The work vehicle can be moved forward in the high-speed driving range through the transmission.

When switching from the high speed running range to the low speed running range, the clutch pedal 28 is depressed to release the restraint device 21 and shift the gear shift lever 6 from the guide groove 8b side to the guide groove 8a side in the same manner as described above. By moving, the work vehicle can be continuously and continuously variable-speed driven in the low-speed traveling range.

Further, as shown in FIG.
By using No. 1, it is possible to switch the working vehicle to the high-speed traveling range from the maximum speed position in the low-speed traveling range through the power take-off transmission.

Next, the operation of the embodiment of the present invention will be described.

Based on the above structure, when the work vehicle is used for general work, the transmission lever 6 is tilted back and forth in the guide groove 8a so that the trunnion of the hydrostatic drive transmission 2 is moved through the connecting link 22 and the lever 23. By rotating the shaft 5 and through the hydrostatic drive transmission 2, the work vehicle can be continuously and continuously variable-traveled in the low-speed traveling range.

On the other hand, when traveling on the road, the clutch pedal 28
By depressing, the restraint device 21 is released, the shift lever 6 is moved from the guide groove 8a side to the guide groove 8b side,
The work vehicle can be advanced at high speed by switching to the high-speed traveling range through the power take-off transmission.

[0026]

The present invention transmits power from a prime mover to two systems, a traveling system and a power take-out system, and in a working vehicle equipped with a hydrostatic drive transmission system in the traveling system, the low-speed traveling region has the hydrostatic pressure. A high speed traveling range is switched to the power take-out transmission by using a drive transmission, and the hydrostatic drive transmission and the power take-out transmission are switched to a shift operation means of the hydrostatic drive transmission. Since the operation can be switched by one operation means that also serves as the speed change operation means of the power take-out system, the structure is simplified and the speed change operation is facilitated.

[Brief description of drawings]

FIG. 1 is a side view of a transmission device according to an embodiment of the present invention.

FIG. 2 is a sectional view of a transmission.

3A and 3B show a speed change lever according to an embodiment of the present invention, FIG. 3A is a plan view of a lever guide, and FIG. 3B is a rear view of the speed change lever;
(C) is a side view of the shift lever.

FIG. 4 is a view showing a shift lever according to another aspect of the present invention.

[Explanation of symbols]

 2 Hydrostatic drive gearbox 3 Transmission 5 Trunnion shaft 6 Gearshift lever 8 Lever guide 10 Gearshift 15 Boss bracket 17 Boss bracket 21 Checking device

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Eiji Harada Eiji Harada, Izumo-cho, Yazuka-gun, Shimane Prefecture 667 Izaya-cho, Ojiya-cho, 1 Mitsubishi Agricultural Machinery Co., Ltd. (72) Kazushige Ikeda, Izumo-cho, Yatsuka-gun, Shimane Prefecture 667 1 Mitsubishi Agricultural Machinery Co., Ltd. (72) Inventor Akimasa Kimura Ojiyacho, Higashi-Izumo-cho, Yatsuka-gun, Shimane Prefecture 667 Address 1 Mitsubishi Agricultural Machinery Co., Ltd. (72) Yoichi Nakasa, Ojiya-cho, Higashi-Izumo-cho, Yatsuka-gun, Shimane Prefecture 667 1 Mitsubishi Agricultural Machinery Co., Ltd. (72) Inventor Masaaki Ito, Izumo-cho, Yatsuka-gun, Shimane Prefecture 667 Iba-cho, Izamachi 1 Mitsubishi Agricultural Machinery Co., Ltd.

Claims (1)

[Claims] 1. A working vehicle in which power from a prime mover is transmitted to two systems of a traveling system and a power take-out system, and the traveling system is provided with a hydrostatic drive transmission, in a low-speed traveling region, the hydrostatic drive transmission is used. In the high-speed running range, the power transmission system transmission is switched, and the hydrostatic drive transmission and the power extraction system transmission are switched to the hydrostatic drive transmission gear shift operation means and the power transmission. A shift operating device for a working vehicle, wherein the shift can be switched by one operating device that also serves as a shift operating device of the system.