JP2559671Y2 - Work vehicle steering mechanism - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure for operating a hydraulic actuator and a hydraulically-operated steering device by a single hydraulic pump by interlocking a transmission for changing vehicle speed and a hydraulic actuator.

[0002]

2. Description of the Related Art Conventionally, there has been known a configuration in which a main shift of a work vehicle is performed using a hydraulic clutch type transmission, and the operation of a hydraulic actuator for driving the work device is controlled in conjunction with the shift. . For example, actual fairness 2-42
507 publication.

[0003]

In such a conventional technique, the hydraulic oil is supplied from a separate hydraulic pump to the hydraulic actuator for driving the working device and the hydraulically operated steering device. Therefore, a hydraulic pump for operating the hydraulic clutch type transmission is required, and a large number of hydraulic pumps are required, resulting in a high-cost hydraulic device.

[0004]

The problem to be solved by the present invention is as described above. Next, means for solving the problem will be described. An on-off valve 50 for controlling the operation of the hydraulic actuator 15 is inserted and installed in an oil supply circuit connecting the hydraulic pump P2 and the hydraulic actuator 15 for driving the working device, and the on-off valve 50 is connected to a transmission for changing the vehicle speed. In a configuration in which switching is performed in conjunction with a shift operation, the hydraulic pressure
Via an on-off valve 50 to actuate the actuator 15
Refueling has been pressurized oil, the oil returning circuit to the hydraulic oil tank, hydraulic type steering apparatus for power transmission and braking and blocking lateral Germany <br/> standing manner from the transmission to the left and right crawler unit Connected to the lubrication circuit of FIG.

[0005]

With this configuration, the operation of the hydraulic actuator for driving the work implement is controlled in conjunction with the gear shifting operation of the transmission, but the oil from the hydraulic pump when the hydraulic actuator is not operating is of course controlled. That is, when the hydraulic actuator is operated, the relief oil flows through the respective open / close valves to the return oil circuit, and is constantly supplied to the oil supply circuit of the hydraulically operated steering device. Regardless, the hydraulically operated steering device can be activated at any time.

[0006]

Next, an embodiment in which a traveling vehicle is a combine will be described. FIG. 1 is a skeleton diagram of a transmission, FIG. 2 is a sectional view of a hydraulically operated steering device, and FIG. 3 is a hydraulic circuit diagram of the present invention. In FIG. 1, an input shaft 2 is horizontally mounted on a transmission case, an input pulley 3 is fixedly mounted on one end of the input shaft 2, and hydraulic pumps P1, P2 are mounted on the other ends.
The loose fitting gear 4 and the sliding double gear 5 are externally fitted on the input shaft 2 in the transmission case, and by sliding the sliding double gear 5, the gear on the sub-transmission shaft 6 is moved. 8.9 and
The gear 7 on the auxiliary transmission shaft 6 is engaged with the loose fitting gear 4 by a locking claw.
Are selectively engaged with each other to enable three-stage sub-shifting.

The sliding gear 5 always meshes with the wide gear 12 on the intermediate shaft 11, and slides on the cylindrical shaft 14 a loosely fitted on the power take-out shaft 16 by the gear 13 on the intermediate shaft 11. The power is transmitted to a double gear 14b, and the cylindrical shaft 14a can rotate integrally with a power take-out shaft 16 via a hydraulic actuator 15 composed of a hydraulic clutch. An output pulley 17 is fixed to the power take-off shaft 16 so that a work machine (reaper) (not shown) can be driven. The sliding double gear 14b is selectively meshed with the gear 13 and the wide gear 12 by sliding, thereby enabling two-stage shifting.

The gear 9 on the auxiliary transmission shaft 6 is
The gear 23 loosely fitted on the transmission and the gear 24 loosely fitted on the two-speed transmission shaft 22 mesh with the gear 10 fixed on the auxiliary transmission shaft 6 and the gear 25 loosely fitted on the single transmission shaft 21 with the gear 25. Gear 25
Is meshed with the gear 26 loosely fitted on the speed change shaft 22. A one-speed hydraulic clutch F1 is interposed between the transmission single shaft 21 and the gear 25, and the transmission two shaft 22 and the gear 24
A second speed hydraulic clutch F2 is interposed between the
A third-speed hydraulic clutch F3 is interposed between the transmission and the gear 23, and a reverse-speed hydraulic clutch R is interposed between the transmission two-shaft 22 and the gear 26 to constitute a three-stage forward and one-stage reverse hydraulic clutch type transmission. Then, by turning a main transmission lever (not shown) and switching a switching valve 43 to be described later, the respective hydraulic clutches are brought into contact, and a shift is performed.

A gear 2 formed at the center of the transmission shaft 21
7, and a gear 28 formed at the center of the transmission two shaft 22 meshes with a gear 30 fixed on the side clutch shaft 29, and a brake drum 32 is fixed to the end of the transmission two shaft 22 to constitute a parking brake. ing. Inner teeth 30L and 30R are formed on both side surfaces of the gear 30 on the shaft center side, and a side clutch is configured so as to be able to mesh with the gears 33L and 33R loosely fitted on the side clutch shaft 29. A side brake SBL / SBR is formed in between,
The gears 33L and 33R always mesh with the gears 34L and 34R on the axles 31L and 31R, and sprockets 35L and 35R are fixed to both ends of the axles 31L and 31R so that the left and right crawler devices can be driven.

The hydraulically actuated steering device comprises a combination of the side clutch and the side brake, and the specific configuration thereof will be described with reference to FIG. Bosses with splines are integrally formed on the shaft ends of the gears 33L and 33R urged in the direction of meshing with the internal teeth 30L and 30R. On the cover 29a supporting the shaft end of the side clutch shaft 29, locking claws are formed at several places in the circumferential direction toward the inside of the transmission case, and a friction plate of a side brake is provided between the boss portion and the locking claws. The cover 29a
A cylindrical portion is integrally extended from a transmission case portion to which the boss is attached to a position substantially in the longitudinal direction between the boss portion and the gears 33L, 33R, and the cylinders 1a, 1a
Is formed and a piston 41 is provided, and the piston 41 is brought into contact with the boss via a thrust bearing.

The cylindrical portion is provided with oil supply passages 1b and 1b communicating with the cylinders 1a and 1a, and is connected to an oil passage 39a of an oil passage plate 39 attached to a side surface of the transmission case. The oil is supplied from the oil passage 39a to the cylinders 1a and 1a, and the piston 41 is caused to stroke.
The L.33R is moved in the opposite biasing direction, the side clutch is disengaged, and then the side brake is activated. Incidentally, oil discharge passages 1c, 1c are opened at portions of the cylinders 1a, 1a corresponding to the side clutch disengagement stroke of the piston 41, and connected to the oil passage 39b of the oil passage plate 39, and a sequence valve 55L, 55R described later By selectively connecting to the tank side, only the side clutch is disengaged and the side brake is not operated.

The hydraulic clutches F1, F2, F
The 3R and hydraulic actuator 15 and the left and right cylinders 1a of the hydraulically actuated steering device are connected as shown in the hydraulic circuit shown in FIG.

That is, the pressure oil from the hydraulic pump P1 can be supplied to the hydraulic clutches F1, F2, F3, and R via the switching valve 43. By switching the switching valve 43, the hydraulic clutch can be selectively used. When the shift is switched, a delay relief valve 44 and an open valve 45 are provided on the primary side of the switching valve 43 so that a shock does not occur when the shift is switched.

The pressure oil from the hydraulic pump P2 is branched from the flow divider 46 in two directions, and one of them is connected to a hydraulic cylinder 48 via a switching valve 47 so that the working machine A (the reaper) can be raised and lowered. , Flow Divider 46
The other branch is connected to an oil supply circuit 49 of the hydraulic actuator 15, and an opening / closing valve 50 that is switched in conjunction with the switching valve 43 is inserted into the oil supply circuit 49. The on-off valve 50 is provided with a position in which the oil supply circuit 49 can communicate and supply oil to the hydraulic actuator 15 only when the switching valve 43 is in the first forward speed, the second speed, and the third speed.
And a position for connecting the oil supply circuit 49 to the return oil circuit 53. Reference numeral 51 denotes a work (cutting) operation switching valve,
The hydraulic actuator 15 can be turned ON / OFF artificially. Reference numeral 52 denotes a relief valve for setting the operating oil pressure of the hydraulic actuator 15, and the relief oil flows to a return oil circuit 53.

A return oil circuit 53 of the on-off valve 50 is connected to an oil supply circuit of the hydraulically operated steering device. That is, the oil flowing from the return oil circuit 53 of the on-off valve 50 is supplied to the oil supply port of the steering switching valve 54b through the neutral position of the solenoid valve 54a. When the steering switching valve 54b is switched from the neutral position to the left or right operating position by a steering lever (not shown), the oil pressurized by the variable relief valve is supplied through the pilot pressure operated sequence valve 55L or 55R. Oil is supplied from the roads 1b to the right or left cylinders 1a. In this state, the sequence valves 55L and 55R are at the positions shown in the drawing, and block the oil discharge passages 1c and 1c from the tank.

The solenoid valve 54a is driven by an automatic control circuit or the like (not shown). When the solenoid valve 54a is switched from its neutral position to one of the left and right working positions, the oil from the return oil circuit 53 of the on-off valve 50 is released. Is the sequence valve 55L / 55R
Flow through the pilot oil passage 56L or 56R and switch the sequence valve 55L or 55R to the oil discharge passage 1c.
Is supplied from the oil supply passages 1b, 1b to the left or right cylinder 1a, 1a in a state of being communicated to the tank side via the neutral position of the steering switching valve 54b. Therefore, although the piston 41 strokes inside the cylinder 1a, it is stopped at the stroke up to the opening of the oil discharge passage 1c.

In such a configuration, the hydraulic pump P1
The hydraulic oil from the hydraulic clutches F1, F2, F3 is turned by turning the main shift lever to switch the switching valve 43.
The oil is fed to one of the R, the clutch is engaged, and the shift is performed.
Can also be switched. When the open / close valve 50 is switched, the pressure oil from the hydraulic pump P2 is supplied to the oil supply circuit 49 of the hydraulic actuator 15 at the forward first speed, second speed, and third speed, and when the work operation switching valve 51 is switched, the hydraulic pressure is changed. When the work machine A is driven by turning on the actuator 15 and the main shift lever is switched to the neutral or reverse speed in this state, the on-off valve 50 is also switched at the same time, and the hydraulic oil from the hydraulic port P2 is directed to the hydraulic actuator 15 side. Is supplied to the return oil circuit 53 without being supplied, the hydraulic oil of the hydraulic actuator 15 is drained, and the work implement A is not driven.

When the hydraulic actuator 15 is operating, the relief oil set to the operating oil pressure by the relief valve 52 flows through the on-off valve 50 to the return oil circuit 53, and the hydraulic actuator 15 Is not operating, the oil from the oil supply circuit 49 passes directly through the on-off valve 50 and returns to the oil circuit 53. Therefore, regardless of whether the hydraulic actuator 15 is operated or not, the hydraulically operated steering device Oil is constantly supplied to the oil supply ports of the solenoid valve 54a and the steering switching valve 54b.

By turning the steering lever appropriately, the steering switching valve 54
When b is switched to the operating position, the oil pressurized by the variable relief valve is supplied to the left or right cylinder 1a, 1a, and the piston 41 separates the gears 33L, 33R from the internal teeth 30L, 30R. One of the side clutches is disengaged, and then the friction plate is pressed to actuate the side brake to brake the axle and turn the aircraft.

Since the relief pressure of the variable relief valve increases and the pressing force of the friction plate of the side brake increases in proportion to the amount of turning operation of the steering lever, the vehicle has an arbitrary turning radius from a gentle turn to a sharp turn. Is obtained. When the electromagnetic valve 54a is driven by an automatic control circuit (not shown) or the like, the sequence valve 55L or 55R is switched and the return oil circuit 5 of the on-off valve 50 is connected with the oil discharge passage 1c communicating with the tank side.
Since the oil from 3 is supplied to either the left or right cylinder 1a, the piston 41 can only obtain a stroke enough to disengage the side clutch, and the vehicle only makes a gentle turn.

[0021]

[Effects of the Invention] The present invention is constructed as described above, and has the following effects. First, the hydraulic pump P2
And hydraulic actuator 15 for working device drive
Operation of the hydraulic actuator 15 during the refueling circuit
The on-off valve 50 for controlling the valve is inserted and installed.
The gear is changed in conjunction with the speed change operation of the speed change transmission.
When the speed change operation is at a constant forward speed,
Actuation of the hydraulic actuator 15
You can have a relationship, if the driving stops or after
In the case of forward movement, the hydraulic actuator 15 is operated.
Operation of stopping the operation of the work equipment becomes possible.
It is a thing. Second, since the return oil from the hydraulic actuator 15 for driving the working machine or the opening / closing valve for controlling the operation of the hydraulic actuator 15 is supplied to the oil supply circuit of the hydraulically operated steering apparatus, the hydraulic actuator and the steering The device can be driven by one hydraulic pump, and the number of parts can be reduced, thereby reducing the cost of the hydraulic device.

[Brief description of the drawings]

FIG. 1 is a skeleton diagram of a transmission.

FIG. 2 is a sectional view of a hydraulically operated steering device.

FIG. 3 is a hydraulic circuit diagram of the present invention.

[Explanation of symbols]

 P1, P2 Hydraulic pump F1, F2, F3, R1 Hydraulic clutch SBL, SBR Side brake 15 Hydraulic actuator 43 Switching valve 50 On-off valve

Claims (1)

(57) [Scope of request for utility model registration] 1. An on-off valve 50 for controlling the operation of the hydraulic actuator 15 is inserted and installed in an oil supply circuit connecting the hydraulic pump P2 and a hydraulic actuator 15 for driving a working device, and the on-off valve 50 is changed in vehicle speed. In which the switching is performed in conjunction with the speed change operation of the transmission, the opening / closing valve 5 is operated to operate the hydraulic actuator 15.
Return oil of hydraulic oil supplied to the hydraulic oil tank via oil
The circuit, the power transmission from the transmission to the left and right crawler unit, work vehicle steering mechanism, characterized in that connected to the oil supply circuit of the hydraulic type steering apparatus for braking by blocked lateral independently.