JPS60245836A - Hydraulic side-clutch apparatus - Google Patents

Abstract

PURPOSE:To improve the operation feeling for a hydraulic side-clutch apparatus by installing a relief valve between a pump and selector valves and setting high the relief pressure of the relief valve, linked with the operation amount of a side-clutch operating lever. CONSTITUTION:The captioned side-clutch apparatus is equipped with a relief valve 32 between a pump P and selector valves 22l and 22r, and said relief valve 32 is interlocked with the side-clutch operating levers 31l and 33r, and the relief pressure is set high according to the operation amount of the operating lever. Therefore, a damping force can be generated according to the operation amount of the operating lever, and the operation with good feeling can be performed by adjusting the manipulation amount of a machine body by the operation force of the operating lever.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Industrial Application Field The present invention relates to a hydraulic side clutch device used in a work vehicle such as a combine harvester. The present invention relates to an adjustable hydraulic side clutch device.

(B) Conventional technology Conventionally, hydraulic side clutch devices have a fixed relief pressure, so the oil temperature rises during unloading, and it is necessary to increase the capacity of the engine case or install a cooler, which is expensive. Although the operating force is lighter compared to a manual side clutch device, the sudden activation of the clutch and brake results in a poor feeling, especially during automatic direction control, and extremely poor ride comfort. It was difficult to handle. In addition, as shown in FIG.
It is an open center type, and the pressure oil from the switching valve 1 is communicated with the hydraulic cylinders 21゜2r of the left and right side clutch devices, and is branched into a pipe line from the hydraulic pump P to the switching valve 1 to form a two-port switching valve 5. communicates with the low pressure relief valve 6 and the high pressure relief valve 7 through the A hydraulic side clutch device was devised in which the high-pressure relief valve 7 is operated during turning control to set the braking force of the side clutch to a strong level so that the turning is performed relatively rapidly (1983-
(See Publication No. 183443).

(c) Problems to be Solved by the Invention However, in this hydraulic side clutch device, when manually operated using the operating lever, the clutch and brake still operate suddenly, giving a poor operating feeling.Furthermore, in the open center type, In products such as transmissions for work vehicles that use both hydraulic oil and transmission oil and are used under a considerable range of temperature conditions, take into account back pressure due to the increased resistance of oil pipes at low temperatures. do,
Hydraulic cylinder 2I! , 2r must be made stronger, or the diameter of the return pipe must be increased, making it impossible to make the device compact.

(d) Means for Solving the Problems The present invention aims to solve the above-mentioned problems by (1) disposing a relief valve branching from the pipe line between the pump and the switching valve; The relief pressure of the relief valve is set low, and the relief valve is set to be linked to a side clutch operating lever so that the relief pressure of the relief valve increases in accordance with the amount of operation of the operating lever. It is something.

(E) Effect Based on the above configuration, the hydraulic pressure sent to the hydraulic cylinder increases in accordance with the amount of operation of the operating lever, and a braking force corresponding to the amount of operation of the operating lever is applied to the side clutch device.

Embodiments Hereinafter, embodiments embodying the present invention will be described with reference to the drawings.

As shown in FIG. 1, the transmission section 11 of the combine includes left and right side clutch devices 12J and 12r. Further, the mission section 11 has a mission case 13, and a steering shaft 15 is freely supported on the case 13. Furthermore, a center gear 16 is supported at the center of the steering shaft 15 so that it can only rotate freely and is prevented from moving left and right, and left and right dock gears 1'7j' and 17r are supported at the left and right parts of the steering shaft 15. is supported so as to be movable left and right and rotatable. Furthermore, center gear 1
Dock claws 16a are provided on the left and right sides of 6, respectively.

16b is formed, and the dock claws 16a, 16b can engage with left and right dock gears 17J, 17r. In addition, left and right hydraulic pistons 201.20r are connected and arranged on the left and right dock gears 171.1'7r via thrust bearings 19, respectively, on the left and right inner sides of the center gear 16, and the pistons, the center gear 16, and the steering shaft The left and right hydraulic cylinders 21 and 2r constituted by the left and right hydraulic cylinders 21 and 2r respectively communicate with the switching valves 221 and 22r via an oil passage 21a formed in the case 13 and an oil passage 21b formed in the steering shaft 15 (second (see figure). Furthermore, left and right dock gear 174'
, 17r are provided with wet multi-disc brakes 23/, 23r, respectively, and return springs 25, 25 are compressed. Rotation is transmitted from Enojin to the center gear 16 via a gear 26, and the left and right dock gears 171 and 17r each have left and right axles 271! , 27r are engaged with the axle gears 291.29r.

Further, the left and right switching valves 221 and 22r, as shown in FIG. 2, are composed of three boat switching valves, each of which has a solenoid 301 for automatic direction control operated by a direction sensor. 3
0 r, and side clutch operating levers 311, 31r
can be operated by. In addition, the left and right switching valves 221, 22r
are supply boats AI communicating with the left and right hydraulic cylinders 21 and 2r, respectively.

A r, tank boat TJ connected to tank T, Tr
1 and a pump boat P J communicating with pump P.

It has a pump P and a switching valve 221゜22.
A relief valve 32 is disposed in a branched line between r and r. The relief valve 32 has a low relief pressure in its normal state, and its set length is adjusted in conjunction with the left and right operation levers 311 and 31r by the balance spring 32a, so that the relief pressure can be adjusted.

FIG. 3 is a diagram showing a device embodying the above-described hydraulic control circuit, and the hydraulic control device 35 has a case 36. As shown in FIG. Left and right solenoids 3 are installed on one side of the case 36.
0J and 30r are stored and fixed, and the other side has a spool hole 37J for the left/right switching valve 221.22r.
, 37r are drilled. These spool holes 371° and 37r have left and right spools 39R and 3, respectively.
9r are inserted into the spools, and one end of these spools protrudes from the case 36 and is connected to the operating levers 314' and 31r, and the other end of the spool is connected to the left and right solenoids 301.
．． 30r plunger 40 p 40 can abut. Further, return springs 41 and 41 are compressed on the other side of the spools 391 and 39r, and the connecting plate 4
2, 42 are fixed. On the other hand, a hole 43 for the relief valve 32 is bored in the center of the case 36, and a valve 45 is disposed in the hole 43 and biased by a balance spring 32a. Further, the other end of the spring 32a is received by an adjusting plunger 46, which extends through a lid 47 closing the hole 43 and facing the connecting plate 42, 4.2. positioned. In addition, the left and right solenoids are 30J! , 30r are set to be relatively small, so the amount of operation of the spools 394', 39r is better with the solenoid 3o4°30r than with the operating lever 311),'
It is smaller than that according to 31 r.

Since the present embodiment has the above-described configuration, when the combine harvester runs straight, the rotation from the engine is transmitted to the center gear 16 via the gear 26, and the rotation from the left and right dock claws 16 is further transmitted to the center gear 16 through the gear 26.
a, 16b to the left and right dock gears 171.17r, and then via axle gears 291, 29r to the left and right axles 271! , 27r are transmitted with the same speed rotation. At this time, the pump boats PR and Pr of both the left and right switching valves 221 and 22r are closed, but in a normal state, that is, a state in which the operating levers 3-IJ and 31r are not operated in the same manner, the relief pressure of the relief valve 32 is The pressure oil from the pump P is discharged to the tank T without any trouble through the relief valve 32.

In this state, for example, the left side clutch operating lever 314
When lightly pulled, the pump port PIV of the left switching valve 221 communicates with the supply port 1-AI, and the pressure oil of the pump P' is supplied to the hydraulic cylinder 2I of the left side clutch device 12J. However, when the lever 311 is lightly pulled, that is, when the amount of movement of the spool 391 is small, the connecting plate 42
is not in contact with the adjusting plunger 46 or is in a state where the plunger 46 has moved slightly, and therefore the spring 32a of the relief valve 32 is in a state where its set length is long, that is, the biasing force of the spring 32a is weak and the relief pressure is low. It is in a small state. Therefore, the oil pressure supplied to the left hydraulic cylinder 21 is relatively low, and the left dock gear 171 is returned via the hydraulic piston 19 and moved against the spring 25, disengaging from the dock pawl 16a and clutching the clutch. is in a disconnected state, but it does not contact the brake 234, or even if it does, it contacts with a weak pressing force, and almost no braking force is applied. Therefore, the left side clutch 121 is simply in a free state in which the transmission is cut off, and the direction of the aircraft is smoothly corrected within a large radius.

For example, if the left side clutch operating lever 3]l is strongly pulled, pump pressure oil is similarly supplied to the left hydraulic cylinder 21, and at the same time, the connection plate 42 is moved to the adjustment plunger 46 based on the large amount of movement of the spool 391. Upon contact, the plunger 46 moves in a direction to compress the spring 32a. Then, the relief valve 32 releases its spring 3.
The set length of 2a is shortened and a strong biasing force is applied, and the relief pressure is adjusted to be high. For you,
The oil pressure supplied to the left hydraulic cylinder 21 is relatively high, and the left dock gear 17J moves largely against the return spring 25, disengaging from the dock pawl L6a and becoming a disengaged clutch. The left dock gear 171 is brought into pressure contact with the left wet multi-disc brake 231 and is in a braked state. In this state, the left side clutch device 121 and therefore the left axle 271 are in a fixed state, and the aircraft is turned around rapidly. In this way, the operating lever 3'l
A braking force proportional to the operation amount of jl or 31r acts on the left and right side clutch devices 121 or 12r.

On the other hand, when the left solenoid 301 is excited by the automatic direction control signal from the direction sensor, the plunger 40
protrudes and moves the spool 391. As a result, pump pressure oil is supplied to the left hydraulic cylinder 21, but the stroke of the plunger 40 is set small, so that the connecting plate 42 does not contact the adjusting plunger 46 or slightly contacts the operating lever 311. The state is similar to that of lightly pulling. Therefore, during automatic direction control, the left axle 271! is in a nearly free state, and the aircraft is smoothly corrected in direction with a large radius.

(G) As described in detail, according to the present invention, the relief valve 3 is branched from the pipe line between the pump P and the switching valves 22J and 22r.
Since the relief pressure of the relief valve is set low, it is possible to prevent the oil temperature from rising during unloading, and the switching valves 221 and 22 divert the waste oil from the hydraulic cylinders 21 and 2r to the tank T. Dedicated tank boats Tl, Tr
Coupled with this fact, the transmission 11 can be configured compactly and a good lubrication state can be maintained. In addition, the relief valve 32 is linked to the side clutch operating lever 311°31r, and the relief pressure of the relief valve is set to increase according to the amount of operation of the operating lever, so that the side clutch 12I!
, 12r can be applied with a braking force according to the amount of operation of the operating lever, and the amount of steering of the aircraft can be adjusted by the operating force of the operating lever to perform operations with a good feeling. In addition, the solenoid operated during automatic direction control, Id 30
1! , the operating lever 31 controls the plunger stroke of 30r.
If the operating stroke is set smaller than that of J, 31r, the aircraft can turn sharply with a small radius by operating the operating lever when turning, but the braking force acting on the side clutch device during automatic direction control is small.
It is possible to smoothly steer the aircraft and improve the uncomfortable ride caused by large vibrations of the aircraft, and it is also possible to prevent problems such as the divider pushing into the adjacent row and pushing down the culm due to excessive vibration of the aircraft, and it is also possible to reverse the problem. It is possible to prevent hunting caused by this and improve the lifespan.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a hydraulic side clutch device according to the present invention, FIG. 2 is a hydraulic control circuit diagram thereof, FIG. 3 is a sectional view showing a hydraulic control device embodying a hydraulic control circuit, and FIG. The figure shows a conventional hydraulic control circuit. 21.2r・Hydraulic cylinder, 11° Transmission part, 12I, 12r-Side clutch device, 1
71,17r...Dock gear, 221,22r...
・Switching valve, 234! , 23r... (wet multi-plate) brake, 301.30r ・Solenoid, 311° 31
r...operation lever, 32...relief valve, 32a
・・Balance spring, 39J, 39r・・Spool, 46・・Adjusting plunger, P・Pump, T・Tank Applicant Mitsubishi Agricultural Machinery Co., Ltd.

Claims (1)

[Claims] (1) Pump pressure oil is communicated with the hydraulic cylinders 24, 2r via the switching valves 221, 22r, and the dock gear 171.1
In the hydraulic side clutch device 121゜12r that moves the dock gear 7r to cut off the transmission and then presses the dock gear against the brakes 231 and 23r for braking, a relief valve is branched from the pipe between the pump P and the switching valve. 32, the relief pressure of the relief valve is set low, and the relief valve is connected to the side clutch operating levers 31.4', 31.
A hydraulic side clutch device characterized in that the relief pressure is set to increase in accordance with the amount of operation of the operating lever in conjunction with r.