JPS5821817Y2 - Hydraulic steering control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device in which a steering mechanism, which is equipped with a device for independently braking left and right traveling devices, is operated by a hydraulic cylinder driven by a pump.

The above device has the advantage that it can be operated very easily compared to conventional systems in which the brake device is manually operated. It has the disadvantage that it can only be controlled in the operating state, and therefore its turning radius is fixed, making it difficult to perform delicate turning operations.

For this reason, it may be possible to adjust this turning angle by changing the driving rotation speed of the pump, but this not only requires a complicated configuration such as a separate transmission mechanism, but also requires such a transmission mechanism. The mechanism must be operated in a separate system from the control pulp that controls the relative operating states of the hydraulic cylinders, which has the drawback of making steering operations cumbersome and awkward.

In view of these circumstances, the purpose of the present invention is to provide a hydraulic steering device that allows easy and delicate steering operations through simple structural improvements that do not require a complicated and expensive transmission mechanism. shall be.

In other words, the present invention makes it possible to easily operate the braking devices by configuring the braking devices that independently apply braking to the left and right traveling devices to be operated by hydraulic cylinders driven by pumps. , a variable relief pressure type relief valve is provided in the pressure oil supply path to the hydraulic cylinder, and the braking force is varied as the relief pressure fluctuates, so the control can be achieved without the need for a separate pump speed change mechanism. Since delicate turning operations are possible by controlling the power, and adjustment of the relief pressure of this relief valve is sufficiently possible by a reciprocating operation in one direction, it is possible to perform operations by changing the relative operating state of the two hydraulic cylinders. By operating the operating tool, the operating tool of the control pulp that controls the steering direction is configured to reversibly increase the relief pressure of the relief valve as the operating tool of the control pulp is moved in the operating direction after controlling the steering direction. It is also extremely easy to configure the system to control the relief pressure of the relief valve.
In this way, by controlling the steering direction and adjusting the braking force using the same operating system, it has become possible to perform the steering operation with an extremely easy operation similar to the conventional manual operation pattern.

In summary, by using the variable relief pressure relief valve as described above, although the structure is extremely simple, the steering operation can be performed lightly, easily, and delicately.

Next, an embodiment of the present invention will be described using a steering operation device for a mobile agricultural machine such as a combine harvester as an example.

1. To explain based on FIG. 1, the left and right traveling devices 1, 1
large latch 2, 2' for driving and releasing the drive, respectively; and a brake 3 for applying braking force to the respective traveling devices 1, 1'.
In the steering mechanism 4 provided with the clutch 2.31, the clutch 2. The operating levers 5 and 5' that turn off the z and apply the rear brakes 3 and 3' are controlled by hydraulic cylinders 6 and 6, respectively.
It is configured to operate at .

Then, the hydraulic cylinder 6.6 is operated by the hydraulic pump 7.
A three-position switching pulp valve is interposed in the configured oil feed path A, and by operating the switching pulp valve, oil is supplied to either one of the hydraulic cylinders 6 and 6'. It is switched to a right-turning state and a left-turning state in which oil is supplied and the other is in an oil-draining state, and a straight-ahead state in which oil is prevented from being sent to both hydraulic cylinders 6 and 6' and both are in an oil-draining state. It looks like it's set up.

The clutches 2, 2' are always biased to the application side, and the brakes 3, 3' are always biased to the non-braking side,
The structure is such that it automatically returns to its original position when it is energized.

Relief valves 9 and 9' that can change the relief pressure are provided in the respective pressure oil supply paths A and A' from the pulp tank to the two hydraulic cylinders 6 and 6'. ' is set so that the internal pressure of the hydraulic cylinder 6.6' is slightly larger than the return urging force of the clutch 2.z in the minimum relief pressure state, and by increasing the relief pressure from this, the brake 3, 3', and the braking force of the brakes 3, 3' is increased by increasing this IJ pressure.

The structure is such that the maximum braking force is exerted by the maximum I717-7 pressure.

Next, referring to FIG. 2, when the left and right steering pedals 10 and 10' provided in the driver's seat are depressed, the first switches 11 and 11' are turned on and operated, respectively. This electrical switch consists of 11, 11
The pulp shaft is configured to be switched to either the left or right direction as desired by the input operation.

Then, by turning on the switch 11, 11', the relief valve on the side that enters the refueling state is connected to the switch 11,
11' is connected in conjunction with the pedals IQ and 10' which have been operated 9, so that as the amount of depression of the pedals 10 and 10' increases, the relief pressure of the relief valves 9 and 9' is increased. It is.

The pedals 10, 10', which are operating tools for switching and operating the pulp 8 in this manner,
As ' moves further in the same direction after the switching operation, the relief pressure of the relief valves 9 and 9' is increased, so that the turning direction and turning radius are controlled by the same operating system. It is configured as shown in the figure.

In addition, instead of the above-mentioned side IJ IJ-f valves 9, 9', a safety relief valve 12 provided in the oil supply path B between the hydraulic pump 7 and the pulp 8 is made capable of changing the relief pressure, and both the pedals 10 , 10' so that the relief pressure is increased by any depressing operation of the pedals 10, 10'.
It is also a good idea to interlock 0' with the relief valve 12.

Note that both pedals 10° and 10' are not interlocked via the relief valve 12.

It should be noted that the pulp control using the pedals 10 and 10' may be controlled by mechanical means such as a release wire, rather than by electrical means as described above.

[Brief explanation of drawings]

The drawings illustrate an embodiment of the hydraulic steering operation device according to the present invention, and FIG. 1 is a simplified explanatory diagram mainly showing the hydraulic system, and FIG. 2 is a partially cutaway side view showing the human operating tool. be. 1, 1'... Traveling device, 3, 3'...
Braking device, 6, 6'...Hydraulic cylinder,...Pulp, 9.9'. 12... Relief valve, io, io'... Operating tool.

Claims (1)

[Scope of utility model registration request] Hydraulic cylinders 6 and 6 each driven by a pump drive the brake devices 3 and 3' that independently apply braking to the left and right traveling devices 1 and 1'.
The hydraulic cylinder 6.6'
A variable relief pressure type relief valve (9
, 9'! 12) is configured to vary the braking force in accordance with fluctuations in the relief pressure, and also includes a control valve that controls the steering direction by changing the relative operating state of the two hydraulic cylinders 6, 6'. As the operating tool 10, 10' continues to be moved in the operating direction after the steering direction has been controlled, the operation is performed such that the relief pressure of the relief valve (9, 9' or 12) is reversibly increased. A hydraulic steering operating device characterized in that it is configured so that the relief pressure of a relief valve (9, 9' or 12) can also be controlled by operating the tools 10, 10'.