JP2852826B2 - Steering operation device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steering operation device which selectively cancels driving of left and right traveling drive devices and enables braking or spin turn.

[0002]

2. Description of the Related Art Conventionally, it has been known to operate a clutch pedal as a means for performing left and right steering operations. For example, there is a technique disclosed in Japanese Patent Publication No. 58-9035, in which the clutch pedal is lightly depressed. By providing a clutch "disengaged" position and a further depressed brake braking position, the turning radius is slightly changed. Also,
In addition to left and right steering, there is also known a technique in which an operating device that enables a spin turn is added. For example, there is a technique disclosed in Japanese Utility Model Publication No. Sho 62-18129 and Japanese Patent Laid-Open Publication No. Hei 1-331473. Is provided with switches on the steering lever and shift guide respectively, left and right steering operations are slid by disengaging the clutch gear via wires, and when further rotated, the brake is braked to reduce the turning radius, and the spin turn is reduced. To do so, turn the steering lever to turn on the shift guide switch, turn on the steering lever switch to operate the solenoid, and turn on the spin turn clutch.
Then one was reversed. In the latter technique, left and right side clutches can be operated by left and right cylinders, and a hydraulic clutch for reversing one axle is provided, so that left and right steering and spin turn can be operated by hydraulic pressure.

[0003]

[Problems to be solved by the invention]
The technique disclosed in Japanese Patent Publication No. 9035 is a configuration operated by a pedal, so it is difficult to stop and operate in the middle of depressing, and the operability is poor. However, since the clutch disengagement and the brake operation are manually operated by the operator, it has been desired that the brake operation is heavy and can be operated lightly by hydraulic pressure or the like. The technique disclosed in Japanese Patent Application Laid-Open No. 1-314673 has improved the operability because the cylinder is operated by hydraulic pressure. However, since the piston is balanced and the clutch is “disengaged”, the pressure is changed by the temperature change of the hydraulic oil or the like. If the oil changes, the piston slides and hinders clutch operation,
Therefore, it was necessary to take a large stroke.

[0004]

SUMMARY OF THE INVENTION In order to solve such a problem, the present invention provides left and right side clutches and side brakes in a transmission case so that the vehicle can turn. In a configuration in which a spin turn is possible by interposing a reverse clutch, a hydraulic actuator for sequentially operating a side clutch "off" and a side brake braking is attached to a transmission case, and the actuator is a piston vertically divided in parallel in a cylinder. A lock member that stops the upper piston at the position where the side clutch is disengaged is arranged in the cylinder chamber, and an oil path is provided in the cylinder that can send pressure oil from this position to the relief valve and the spin turn switching valve. , The spin-turn switching valve may be a spin-turn actuator or a lower piston. It is obtained by configured to oil feed changeover to dynamic side oil passage.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The problems to be solved by the present invention and the means for solving the problems are as described above. Next, the structure of the embodiment shown in the accompanying drawings will be described. FIG. 2 is a steering hydraulic circuit diagram, and FIG. 3 is a sectional view of a steering clutch. In FIG. 1, the power input to the transmission case 1 is shifted through a main transmission and a subtransmission, and transmitted to a center gear 2 fixed on a clutch shaft 16. Side clutches 3L and 3R each composed of a pawl clutch are provided, and sliding gears 4L and 3L loosely fitted on the clutch shaft 16 are provided.
A shift fork which is turned on and off by operating a clutch lever, which will be described later, is provided on the shafts of the sliding gears 4L and 4R by means of the pawls of the 4R and the pawls provided on both sides of the center gear 2. Are provided, and the other end is provided with a brake plate to constitute a part of the side brakes 5L and 5R.

The side clutch 3 may be a multi-plate clutch 3 '. In this case, as shown in FIG. 22, the multi-plate clutch 3 'is pressed in a boosted state via the steel ball 23 to be in the "on" state. And
When the shifter fork 25 is rotated and the fitting portion 6 is slid, the multi-plate clutch 3 'is turned "off" and the center gear 2 is turned off.
When the power transmission from the gear 4 'to the gear 4' is cut off and the shifter fork 25 is further rotated, the side brake 5 is actuated via the sleeve 21 and the steel ball 24 to brake the rotation of the gear 4 '. At this time, the force for pushing the steel ball 24 is also boosted, and the operation can be performed lightly. In this way, the configuration is such that a boosting force is obtained, so that a pressing force equivalent to the hydraulic pressure is obtained, and the loss horsepower is smaller than the hydraulic pressure, so that the operation feeling is improved.

The sliding gears 4L and 4R are axles 9L and 9R.
The gears 7L and 7R fixed on the upper surface always mesh with the gears 7R and 7R.
Is engaged with the gear 10 loosely fitted on the reverse clutch shaft 11, and the shaft portion of the gear 10 is provided with a shifter fork 26 which is rotated by operating an actuator B described later by operating a reverse clutch lever (or switch). A fitting portion 15 is provided, and a clutch plate is provided at the other end so that the reverse rotation clutch 12 is provided.
Form a part of. A gear 13 is fixed on the reverse rotation clutch shaft 11 and meshes with a gear 18 on the intermediate shaft 17, and the gear 18 meshes with a gear 14 fixed on the axle 9L.

With such a structure, when the clutch lever on one side is rotated, the sliding gear 4 on that side slides to disengage the side clutch 3 and the transmission of the driving force is cut off. The turning is performed by driving the other side. When the reverse clutch lever is rotated in this state, the reverse drive is transmitted to one side via the reverse clutch 12 by the reverse drive, so that a spin turn is possible. If the clutch lever is further rotated without rotating the reverse clutch lever, the side brake 5 is operated to stop the rotation of the axle on that side, and the turning radius can be reduced.

The structure of the hydraulic circuit and the hydraulic actuator for rotating the shifter forks 25 and 26 will be described with reference to FIG.
In the actuator A for rotating the piston 5, pistons 31 and 32 are inserted into cylinder chambers 30L and 30R formed in parallel in the cylinder 30, and the pistons 31 and 32 are divided into upper and lower parts, respectively, and the upper piston 31a. 32a
Is configured to be slidable between locking members 33, 33, which are locking rings fitted in the middle of the cylinder chambers 30L, 30R, and the cylinder head, and the sliding amount is determined by the side clutches 3L, 3R. It is set up to the "off" position. The lower pistons 31b and 32b are
The tip of the piston rod which is urged upward by 34 and protrudes downward contacts the arms 35L and 35R which rotate the shifter fork 25 through the cylinder 30.

Then, a switching valve 3 is mounted on the cylinder head.
The oil passages 30a and 30b communicating with the output port 6 are provided. The switching valve 36 is constituted by an electromagnetic valve. When the side clutch lever is rotated, the solenoid on the side is turned off.
N. The left and right cylinder chambers 30L
Three oil passages 30c, 30d, and 30e are drilled between the 30R and 30R to communicate between the two cylinders.
0c is a position where the side clutches 3L and 3R are "disengaged" and communicates with the cylinder chambers 30L and 30R and the oil passage 43 that can be fed to the relief valve 37 and the spin turn switching valve 39, and the oil passage 30d communicates with the tank port. , Oil passage 30e
Indicates that the side clutches 3L and 3R are "disengaged" and communicates with the upper positions of the lower cylinders 31b and 32b and the output port of the spin-turn switching valve 39.

A spin-turn actuator B is connected to another output port of the spin-turn switching valve 39. The spin-turn actuator B inserts a piston 42 into a cylinder 40, and Is biased toward the head side by a spring 43, and the lower end of the piston rod abuts on the arm 42, thereby enabling the shifter fork 26 to rotate.

When turning left in such a configuration, when the left side clutch lever is turned, the solenoid is turned on, the switching valve 36 is switched, and the pressure oil from the hydraulic pump P is supplied as indicated by the solid arrow. The oil is sent to the oil passage 30a and pushes the pistons 31a and 31b. When the piston 31a descends until the piston 31a comes into contact with the ring 33, the piston rod rotates the arm 35L to rotate the shifter fork, and the side clutch 3L is turned "off" to move the power from the center gear 2 to the sliding gear 4L. Is cut off, and only the right axle 9R is driven to turn. At this time, the pressure oil flowing to the oil passages 30c and 43 flows toward the tank via the relief valve 37.

When the side clutch lever is further rotated, the arm 37a interlockingly connected to the spool of the relief valve 37 is rotated, the relief valve 37 is closed, and the oil is supplied to the oil passage 30e as indicated by the dashed arrow. Then, the lower piston 31b is pushed to rotate the arm 35L to rotate the shifter fork 25, and the side brake 5L is operated to stop the rotation of the axle 9L, so that the turning radius can be further reduced. It is.

In this state, the switching valve 39 for spin turn is used.
Is activated, the hydraulic oil flows through the piston 3 as indicated by the solid arrow.
1b is sent to the tank side to turn off the side brake 5L, and is sent to the spin turn actuator B to push the piston 41, rotate the actuator 42 and the shifter fork 26, and rotate the reverse clutch 12 Is set to "on". Therefore, the left axle 9L rotates in the reverse direction to enable a spin turn. Then, turning to the right and spin turn can be performed in the same manner as described above.

[0015]

According to the present invention, the following effects can be obtained. That is, the upper piston is "disengaged" by the locking member provided in the cylinder.
Therefore, the brake is not dragged at the time of the spin turn, and the clutch "disengage", the brake operation, and the spin turn can be reliably performed. Since the operation of the clutch is performed using the hydraulic actuator, the operation can be performed lightly.

[Brief description of the drawings]

FIG. 1 is a skeleton diagram of a steering section in a transmission case.

FIG. 2 is a steering hydraulic circuit diagram.

FIG. 3 is a sectional view of a steering clutch section.

[Explanation of symbols]

 AB Actuator 1 Transmission case 3 Side clutch 5 Side brake 9 Axle 12 Reverse clutch 30 Cylinder 30L / 30R Cylinder chamber 31/32 Piston 33 Locking member 37 Relief valve 39 Switching valve for spin turn

Claims (1)

(57) [Claims] 1. A structure in which left and right side clutches and side brakes are provided in a transmission case to enable turning, and a reverse clutch is interposed between the side clutch and an axle to enable a spin turn. A hydraulic actuator that operates in the order of `` off '' and side brake braking is attached to the transmission case, this actuator houses a piston divided vertically in parallel in the cylinder, and a locking member that stops the upper piston at the position where the side clutch is released The cylinder is provided with an oil passage capable of supplying pressure oil from this position to the relief valve and the spin-turn switching valve in the cylinder, and the spin-turn switching valve is provided with a spin-turn actuator or a lower piston operating side. Steering operation characterized by being configured to switch oil supply to an oil passage apparatus.