JP2000118255A - Transmission for work machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a work machine transmission capable of smoothly changing a shift by utilizing a stationary hydraulic continuously variable transmission. SOLUTION: The hydraulic pump P and the hydraulic motor M of a stationary hydraulic continuously variable transmission 9 for traveling shifting are respectively constituted to be adjusted for capacity, and following the operation of a transmission lever 13 for operating shift for the stationary hydraulic continuously variable transmission 9, switching is made between a first state of making a capacity adjustment only for the hydraulic pump P and a second state of making capacity adjustments for both the hydraulic pump P and the hydraulic motor M.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmission for a working machine such as a combine.

[0002]

2. Description of the Related Art Conventionally, a transmission of a working machine such as a combine machine has a hydrostatic continuously variable transmission, and in order to continuously change and adjust the vehicle speed, a hydraulic pressure of the hydrostatic continuously variable transmission is used. Only the displacement of the pump was adjusted.

[0003]

For this reason, in the conventional transmission of a working machine, a separate gear-type transmission is provided as an auxiliary transmission so that a plurality of high-low sub-transmissions can be performed. . By the way, the shift change of the sub-transmission is performed in a state where the gears are engaged with each other and the operation resistance is high, so that it is difficult to perform the shift change smoothly.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide a transmission of a working machine capable of smoothly performing a gearshift using a hydrostatic continuously variable transmission. .

[0005]

(Structure) A transmission of a working machine according to a first aspect of the present invention is capable of adjusting the capacity of each of a hydraulic pump and a hydraulic motor of a hydrostatic continuously variable transmission for traveling speed change. And a first state in which only the hydraulic pump is displaced with the operation of a shift lever that shifts the hydrostatic continuously variable transmission, and a hydraulic pump and a The hydraulic motor is configured to be switchable to a second state in which the capacity of the hydraulic motor is adjusted together.

(Operation) According to the structure of the first aspect of the present invention, the first state in which only the displacement of the hydraulic pump is adjusted with the operation of the shift lever, and the operation of the hydraulic pump and the hydraulic motor with the operation of the shift lever. Since it is possible to switch to the second state in which the capacity is adjusted together, for example, a mode in which the vehicle travels at high torque and low speed by shifting in the first state and a mode in which the vehicle travels at low torque and high speed by shifting in the second state And the switching between the first state and the second state can be performed continuously without disengaging the clutch, and the resistance action from the transmission system at the time of the switching is small. Therefore, the switching operation can be performed lightly and the switching can be performed smoothly.

(Effects) Therefore, according to the configuration of the first aspect of the present invention, the shift operation can be performed with a single shift lever, and a separate lever for performing a sub-shift operation is not required. Further, even when the gearshift operation is performed by switching the operation state of the shift lever between the first state and the second state, the capacity of the hydraulic pump or the hydraulic motor is adjusted so that only the hydrostatic stepless transmission is operated. Therefore, the shift operation can be performed smoothly with the shock or the like being extremely small, and the operability is improved.

(Structure) According to a second aspect of the present invention, in the transmission for a working machine according to the first aspect, the displacement of the hydraulic motor is steplessly changed according to the operation of the shift lever. Is a characteristic configuration.

(Operation) According to the configuration of the second aspect of the present invention, the change of the capacity of the hydraulic motor is performed in a stepless manner in accordance with the operation of the shift lever. In this state, the capacity of the hydraulic motor can be changed steplessly in accordance with the operation of the shift lever. For example, when the speed is to be greatly increased in the first state,
If the speed change lever is subsequently operated to the high speed side after switching to the second state, it is possible to quickly switch to the high speed state while smoothly increasing the speed.

(Effects) Therefore, according to the configuration of the second aspect of the present invention, when it is desired to significantly increase the speed while traveling, the speed can be smoothly switched, and the speed can be increased quickly and smoothly. Can be performed, and it becomes easy to use.

(Structure) According to a third aspect of the present invention, in the transmission for a working machine according to the first aspect, the displacement of the hydraulic motor is changed to a plurality of stages in accordance with the operation of the shift lever. Is a characteristic configuration.

(Operation) According to the configuration of the third aspect of the present invention, the capacity of the hydraulic motor is changed in a plurality of stages in accordance with the operation of the shift lever. Thus, since the capacity of the hydraulic motor is changed in a plurality of stages, the vehicle speed can be set stepwise so as to obtain a required speed set in accordance with a work speed or the like when traveling while performing work.

(Effects) Therefore, according to the configuration of the third aspect of the present invention, the required speed set in accordance with the work speed or the like when traveling while performing work is stepwise adjusted. Since the vehicle speed can be set, an appropriate speed can be set in advance in a plurality of stages, and the usability is good.

(Structure) According to a fourth aspect of the present invention, there is provided a transmission for a working machine according to the first aspect, wherein the switching operation tool for switching between the first state and the second state is gripped by the shift lever. Is provided as a characteristic configuration.

(Operation) According to the configuration of the fourth aspect of the present invention, since the switching operation tool is provided on the grip portion of the shift lever, a separate shift tool is provided at a position away from the shift lever. In comparison, the first state and the second state can be switched by one-handed operation with the hand operating the shift lever, so that another operation can be performed with the other hand not operating the shift lever.

(Effects) According to the structure of the fourth aspect of the present invention, the shift lever can be operated by one hand and the operation of switching between the first state and the second state can be performed. Excellent ones can be obtained.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a combine as an example of a working machine. This combine mounts a cutting pre-processing device 3 on a front end portion of a body frame 2 supported by a pair of left and right crawler traveling devices 1 and 1 so as to swing up and down around a horizontal axis. A threshing device 4, a boarding operation unit 5, a prime mover 6, a Glen tank 7, and the like are mounted and mounted.

As shown in FIGS. 2 to 5, the power from the engine E of the driving unit 6 is transmitted via a belt-type transmission mechanism 8.
The output of the hydrostatic continuously variable transmission 9 is input to a transmission case 10 and transmitted to the crawler traveling devices 1 and 1.
In order to be driven synchronously with the crawler traveling devices 1, 1,
The configuration is such that an output is separately obtained from the transmission case 10 and the cutting pre-processing device 3 is driven. The transmission to the threshing device 4 is performed in a different system from the transmission to the crawler traveling devices 1 and 1 and the cutting pre-processing device 3.

The hydrostatic stepless transmission 9 is connected to a transmission case 10 by bolts or the like, and the rotational power of the input shaft 9A is inputted to the input shaft 9A by the power from the belt type transmission mechanism 8. Drives the hydraulic pump P. The pressure oil discharged from the hydraulic pump P drives the hydraulic motor M. The hydraulic pump P is a variable displacement swash plate type pump, and a pump operation shaft 11 for changing the swash plate angle protrudes outside the case of the hydrostatic continuously variable transmission 9. On the other hand, the hydraulic motor M is also a variable displacement type swash plate type motor, and a motor operation shaft 12 for changing the swash plate angle protrudes outside the case of the hydrostatic type continuously variable transmission 9. The output shaft 9B of the hydraulic motor M is linked to the transmission case 10 in an interlocked manner. A shift operation lever 13 is provided on the boarding operation unit 5 so as to be able to swing back and forth. The shift lever 13 is configured to be swingable back and forth around the swing center X, and extends to the opposite side with the gripping operation portion 13a of the shift lever 13 between the swing center X. The arm portion 13b is
An operation wire 14 linked to an arm 11A of the pump operation shaft 11 is connected.

A swing operation lever 15 as a switching operation tool is swung about a horizontal axis so that a swing operation can be performed with a fingertip on a grip operation section 13a as a grip section manually operated by the shift lever 13. It is freely supported. The swing operation lever 15 is formed in a bell crank shape, and one end of a rod 16 is pivotally supported on the arm portion 15a of the swing operation lever 15, and the other end of the rod 16 has a sheet metal switching guide. It is pivotally supported at one end of the body 17. That is, the arm portion 15 a of the swing operation lever 15 is pivotally supported on the upper end of the rod 16 vertically inserted into the shaft 18 while being positioned inside the hollow shaft 18 of the speed change lever 13. A switching guide 17 is pivotally supported at the lower end. The switching guide body 17 has a long slot 19 in front and rear.
And the pin 2 inserted into the elongated hole 19 is formed.
0 protrudes from the arm 15a. The upper edge of the elongated hole 19 at the middle position in the longitudinal direction has a step 21.
The front side of the step portion 21 is formed as a front long hole 19R which is wide vertically, and the rear side of the step portion 21 is formed as a rear long hole 19F which is vertically narrow. Switching guide body 1 with 16 lowered most
At the time of the posture 7, it comes into contact with the step portion 21 in the front-rear direction. One end of an operation wire 22 is connected to the front end of the switching guide body 17 so as to advance and retreat in the front-rear direction, and the other end of the operation wire 22 is connected to the arm 12A of the motor operation shaft 12. Connected. Further, the rod 16 is elastically biased so as to be located on the upper side.

With the above configuration, when the shift lever 13 is operated without operating the swing operation lever 15 as shown in FIGS. 2 and 3, the vehicle speed is changed as shown by the solid line in the graph of FIG. Only the change adjustment of the discharge flow rate of the hydraulic pump P of the hydrostatic continuously variable transmission 9 is performed in a state substantially proportional to the operation amount of the lever 13. That is, since the switching guide member 17 has a posture in which the rear end is displaced upward by the rod 16 elastically biased upward, the movement of the pin 20 accompanying the swing of the speed change lever 13 causes the step portion 21 to move. Without contact, the pin 20 can freely move between the front long hole 19R and the rear long hole 19F over the entire range from the zero speed position to the highest speed position, so that the switching guide member 17 is not operated back and forth. Therefore, the hydraulic motor M is maintained at a constant swash plate angle without being subjected to a shift operation. On the other hand, as shown in FIG. 4 and FIG. 5, the swing operation lever 15 is operated together with the shift lever 13 so as to lower the switching guide member 17 downward against the urging force. Then, the rod 16 is lowered, and the pin 20 comes into contact with the step 21.
In this state, when the shift lever 13 is operated from zero speed to the highest speed, as shown by a broken line in the graph of FIG. The vehicle speed is operated to the high speed side by the hydraulic pump P, the hydraulic motor M is maintained at a constant swash plate angle, and the range from the contact of the pin 20 to the step portion 21 to the maximum speed is maintained. In conjunction with the operation of the shift lever 13, not only the hydraulic pump P but also the hydraulic motor M can be switched to the high-speed side by the pulling operation of the operation wire 22, so that only the hydraulic pump P is simply moved to the high-speed side. The vehicle speed is higher than when the vehicle is operated.

[Another Embodiment] FIG. 7 shows a third embodiment of the present invention. That is, the arm portion b that swings integrally with the shift lever 13 and the arm 11A of the pump operating shaft 11 of the hydrostatic continuously variable transmission 9 are linked by the operating wire 14 and the clutch 23 A cam body 24 which can be intermittently connected to the shaft 18 is provided, and a roller 25a contacting the cam body 24 and a roller 25a
a cam follower 25 comprising an arm 25b for swingably supporting the arm a is connected to one end of the arm 25b and the arm 12A of the motor operating shaft 12 of the hydrostatic stepless transmission 9 by an operating wire 22. . The clutch 23 is linked with a switching lever 15 as a switching tool provided on the grip portion 13a of the shift lever 13 via a rod 16 and the like, and is normally biased toward the clutch disengagement side. Also, the clutch 23
Can be performed only when the shift lever 13 is at the zero-speed operation position. The length of the cam body 24 in the radial direction with respect to the outer periphery of the cam body 24 with respect to the swing center X of the shift lever 13 at a plurality of positions corresponding to a predetermined swing angle corresponding to the shift operation of the shift lever 13 is stepwise. A step portion 27 # is formed so as to change in a stepwise manner. Accordingly, when the shift lever 13 is operated with the clutch 23 engaged, the capacity of the hydraulic motor M together with the hydraulic pump P is adjusted so that the speed is increased in a plurality of stages corresponding to the operating position of the shift lever 13 (FIG. 8). On the other hand, clutch 2
When the shift lever 13 is operated in a state where the gear 3 is turned off, the displacement of only the hydraulic pump P is adjusted.

[Brief description of the drawings]

FIG. 1 is an overall side view showing a combine.

FIG. 2 is an explanatory view of a neutral position in a state where a shift lever adjusts the displacement of only a hydraulic pump;

FIG. 3 is an explanatory diagram of a highest speed position in a state where the shift lever adjusts the displacement of only the hydraulic pump.

FIG. 4 is an explanatory view of a neutral position in a state where the shift lever adjusts the capacity of the hydraulic pump and the hydraulic motor.

FIG. 5 is an explanatory diagram of a highest speed position in a state where the shift lever adjusts the capacity of the hydraulic pump and the hydraulic motor.

FIG. 6 is a graph showing a relationship between a lever operation amount and a vehicle speed in the first embodiment.

FIG. 7 is an explanatory view of a neutral position in a state where the shift lever of the embodiment according to claim 3 adjusts the capacity of the hydraulic pump and the hydraulic motor.

FIG. 8 is a graph showing a relationship between a lever operation amount and a vehicle speed in the embodiment according to claim 3;

[Explanation of symbols]

 Reference Signs List 9 hydrostatic continuously variable transmission 13 shift lever 13a grip 15 switching operation tool M hydraulic motor P hydraulic pump

 ──────────────────────────────────────────────────続 き Continued on front page F term (reference) 3D040 AA22 AB04 AC02 AC50 AE19 AF24 3D042 AA01 AB11 BA02 BA08 BA20 BC06 3J052 AA02 BA03 BA12 BA21 CA22 FB01 GA04 HA15 KA01 LA07

Claims (4)

[Claims] A hydraulic pump and a hydraulic motor of a hydrostatic stepless transmission for traveling speed change are each configured to be capable of adjusting the capacity, and a shift lever for shifting the hydrostatic stepless transmission is operated. Accordingly, the work is configured to be switchable between a first state in which only the hydraulic pump is adjusted in capacity and a second state in which both the capacity of the hydraulic pump and the capacity of the hydraulic motor are adjusted in accordance with the operation of the shift lever. Transmission of the machine. 2. The transmission of a working machine according to claim 1, wherein the displacement of the hydraulic motor is steplessly changed according to the operation of the shift lever. 3. The transmission of a working machine according to claim 1, wherein the capacity of the hydraulic motor is changed in a plurality of stages according to the operation of the shift lever. 4. The transmission of a working machine according to claim 1, wherein a switching operation tool for switching between the first state and the second state is provided on a grip portion of the shift lever.