JPS6383469A - Three way high speed pilot valve - Google Patents

Abstract

PURPOSE:To reduce noise and shock in a comparatively simple structure by providing means for controlling input pulse separation of a pulse motor for driving a spool. CONSTITUTION:When a pulse motor 5 is rotated in one direction or rotated normally and reversely, a spool 4 of a rotary spool valve 1 is rotated in a casing 2 to communicate an actuator port A with a tank port and a pump port P alternately. The actuator port pressure is changed by controlling input pulse separation of the pulse motor 5 to change the ratio of the amount of time t1 the actuator port A communicates with the tank port to the amount of time t2 the actuator port A communicates with the pump port P. Thus the actuator port pressure can be controlled without noise of a valve and shock.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a three-way high-speed pilot valve for pilot-controlling valves in hydraulic systems of construction machines, agricultural machines, and other industrial machines.

[Conventional technology]

A three-way high-speed solenoid valve shown in FIG. 4 is known as this type of pilot valve. This valve moves the actuator port 51 alternately between a tank port 57 and a pump boat 58 by moving a spool 55, which has a poppet portion 54 located in an annular groove 52 communicating with the actuator port 51, forward and backward by energizing and de-energizing a solenoid 56. communicate with,
At that time, the energizing/de-energizing time of one time is set to 0.02 seconds, for example, and the ratio of the energizing time to the de-energizing time is changed within that range to adjust the communication time between the actuator bow 1.51 and the pump port 58 and the actuator port 51. By changing the communication time of the tank port 57, the actuator port pressure is controlled and the switching valve etc. are switched.

[Problem that the invention seeks to solve]

However, the valve as described above switches as many as 50 times per second, and each time the taper surfaces 53 before and after the poppet portion 54 come into contact with the corners of the annular groove 53, noise is generated and the annular groove There is a disadvantage that the poppet part is damaged early. Moreover, this three-way isomorphic high-speed solenoid valve has a complicated structure.

The present invention has been made in view of the above-mentioned points, and an object of the present invention is to provide a three-way homogeneous high-speed bi-Japanese-Soviet valve with a relatively simple structure and no noise or impact.

[Means for solving problems]

The structure of the present invention for achieving this purpose will be explained with reference to FIGS. 1 and 2.
A rotary spool valve 1 is configured to alternately communicate an actuator port A with a pump boat P and a tank port T provided in a casing 2 by rotating the spool 4, and a pulse motor 5 for driving a spool 4, Means are provided for adjusting the input pulse interval.

[Function] When the pulse motor 5 is rotated in one direction or in the forward and reverse directions, the spool 4 of the rotary spool valve 1 rotates within the casing 2, alternately communicating the actuator port A with the tank port T and pump bow 1-P. As a result, pressure builds up on actuator bow 1-A.

This actuator port 1 pressure is determined by adjusting the input pulse interval of the pulse motor 5 to increase the communication time between actuator port A and tank boat 1-T, and the ratio t+/jz of the communication time t2 between actuator port A and pump boat P.
That is, the pulse motor 5 changes by changing the
Since it rotates by a unit angle that is a pulse, for example, the pulse interval when communicating actuator port A and pump boat P is shortened in the range of 50 pulses per second, and the pulse interval when communicating actuator port A and tank port T is reduced. When widening, the communication time t2 between actuator port A and pump boat P becomes shorter, and the communication time t between actuator port A and tank port T becomes longer.
Actuator port pressure drops. Conversely, if the communication time t2 between actuator port I-A and pump boat P is lengthened and the communication time (1) between actuator port A and tank port T is shortened, the actuator port pressure will increase. Fig. 3 shows this relationship. It can be seen that the larger the ratio t of the AT communication time t1 to the PA communication time t2, the /lzO value, the lower the actuator port pressure is, and conversely, the smaller it is, the higher it is and approaches the pump discharge pressure.

Actuator port A is intermittently communicated with pump boat P and tank port T, but because the interruption time is short, the actuator port pressure remains constant during the communication time between actuator port A and tank port T. A pressure corresponding to the communication time t2 between the actuator port A and the pump boat P can be obtained.

〔Example〕

Embodiments of the present invention will be described based on the drawings. 1 and 2, a rotary spool valve 1 has a spool 4 rotatably fitted into a valve hole 3 of a casing 2.
The spool 4 is connected to an output shaft 6 of a pulse motor 5 attached to one side of the spool 4, and the spool 4 has two radial through holes 8, 9 and a shaft hole 7 through which these are communicated. The through hole 9 is always communicated with the actuator to turbo-1-A via the annular groove 101 through hole 11 formed in the casing 2, and the through hole 8 is connected to the second actuator by rotating the spool 4 in one direction or in forward and reverse directions. Through holes 12 and 13 formed in casing 2 and through hole 1 as shown in the figure.
4 and 15 alternately communicate with the pump boat P and tank port T.

The pulse motor 5 is digitally controlled by a digital input led from a computer via an amplifier, and its rotational speed is adjusted by changing the pulse interval.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, the input pulse interval of the pulse motor that drives the spool of the low-rise spool valve is adjusted so that the communication time between the actuator port and the tank port and the communication time between the actuator port and the pump boat are adjusted. Since the actuator port pressure is controlled by changing the ratio of , the actuator port pressure can be controlled without valve noise or impact. In addition, the conventional 3
Since a rotary spool valve, which has a simpler structure than a directional high-speed solenoid valve, is used, costs can be reduced, and since it is digitally controlled using digital input, a D/A converter is not required.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway side view of an embodiment of the present invention, FIG. 2 is a sectional view taken along line A-A in FIG. 1, and FIG. 3 is a communication time t between actuator port A and pump port P. ,
FIG. 4 is a longitudinal sectional view of a conventional three-way high-speed solenoid valve. 1. Rotary spool valve, 2. Casing, 4.
Spool, 5...Pulse motor, A...Actuator port, T...Tank port, P...Pump port.

Claims (1)

[Claims] A rotary spool valve has a rotary spool valve that rotates a spool within a casing to alternately communicate an actuator port with a pump port and a tank port provided in the casing, and a pulse motor for driving the spool and an input pulse of this pulse motor. A three-way high-speed pilot valve, characterized in that it is equipped with a means for adjusting an interval.