JPS607147B2 - hydraulic control valve - Google Patents

Description

[Detailed Description of the Invention] This invention provides input/output pipes and a spool chamber for supplying pressure oil to a hydraulic motor in the valve body, and slides the spool housed in the spool chamber with oil. The present invention relates to a hydraulic control valve that operates a hydraulic motor.

Generally, when stopping a hydraulic motor in a hydraulic circuit that is subject to inertial load, the supply of pressure oil from the hydraulic pump is cut off, and at the same time, the pressure oil supply port to the outside of the hydraulic motor is rapidly shut off. When a load is acting on the hydraulic motor,
In order to prevent cavitation, a counterbalance valve is installed between the hydraulic motor and the hydraulic pump, which has the function of opening the pressure oil discharge path only when the supplied pressure oil is sufficient.

Next, an example of the conventional hydraulic system as described above will be explained with reference to FIG.

A spool chamber 17 is provided in the center of the valve body 4, and oil passages 11, 11' and oil grooves 12, 12' are provided in the peripheral wall. Subur 5 is housed in.

The spool 5 is provided with two valve chambers, oil grooves 13, 13', and other oil holes, and the valve chambers are provided with povet valves 7, 7' and springs 16, 16' that press the povet valves, respectively.
is contained. Spring receiving portions 18, 18' are formed at the ends of the spool 5.
, 18' and the inner wall end of the valve body 4, springs 6, 6' are respectively attached via spring receivers 26, 26'. The end faces of the spool 5 face the oil chambers 10 and 10', respectively. The discharge side of the hydraulic pump 1 and the oil tank 15 are connected to the hydraulic switching valve 2, and the hydraulic switching valve 2 and the oil passage 11
, 11' are connected via input pipes 8, 8'.

The oil grooves 12, 12' are connected to the hydraulic motor 3 via output lines 9, 9'. When the hydraulic shutoff valve 2 is in the neutral position shown, the spool 5 is maintained in the central position.

When the hydraulic switching valve 2 is operated and switched to position 1, the oil discharged from the hydraulic pump 1 enters the hydraulic switching valve 2, the input pipe line 8, and the valve chamber of the Pobet valve 7, and the Pobet valve 7 is opened to flow into the output pipe. The hydraulic motor 3 is supplied from the line 9. At the same time, pressure oil enters the oil chamber 10' through the oil passage 11, and moves the spool 5 to the right against the spring 6'. As a result, the oil groove 12' and the oil groove 13', which had been cut off by the spool 5, are connected, and the output pipe 9' and the input pipe 8' are connected.
It's hard to say. In this way, the hydraulic motor 3 is rotated. When the hydraulic switching valve 2 is switched to the m position, the spout
The lever 5 is moved in the opposite direction to the left, and the hydraulic motor 3 is rotated in the opposite direction in the same manner as described above.

When the hydraulic switching valve 2 is returned to the neutral position 0', the pressure oil that was being sent to the input pipe 8 or 8' is returned to the oil tank 15, and the spool 5 is moved as shown in the figure by the reaction force of the spring 6' or 6. The rotation of the hydraulic motor 3 is stopped. Thus, when the hydraulic motor 3 rotates, the pressure of the pressure oil supply boat is determined by the springs 6, 6' at the ends of the spool 5.
This system is designed to prevent cavitation in the pressure oil supply boat, but in order to fully demonstrate its effect, the relationship between the return side of the pressure oil, that is, the oil grooves 12' and 13' or the oil groove 12 and It is necessary to stably and strictly control the opening ratio with respect to 13.

In general, increasing the size of the oil passages 11 and 11' tends to cause the problem that the above-mentioned opening ratio control becomes unstable and difficult, so when installing the throttles 14 and 14' on the oil passages 1 1 and 11', There is. In this case, the speed of the pressure oil flowing in and out of the oil chamber 10 or 10' becomes slow, causing a delay in the movement of the spool 5, and even after the supply of pressure oil stops, the blocking of the oil drain path is temporarily delayed. Cavitation occurs. The applicant of the present invention has already provided a counterbalance valve that solves the above problem in Japanese Patent Application No. 77974/1983.

This is at the end of the subur, which is plunged into the pilot room.
Pistons each equipped with a check valve are inserted movably,
The damping action is caused by the piston only when the end of the spool comes into contact with the inner wall of the valve body. In this configuration, it is necessary to provide a piston insertion hole at the end of the spool along the axis 'D' of the spool, and to perform a damping effect by the gap between the insertion hole and the sliding surface of the piston, a gap is created. It is important to manage this; if the gap is large, the damping effect will be small, and if the gap is small, the sliding performance of the piston will be poor, causing sticking. Furthermore, if the piston insertion hole is not parallel to the spool center, the piston will also stick. This poses a problem in that machining the piston insertion hole provided at the end of the spool is very difficult. This invention was made in view of the above-mentioned problems, and its purpose is to simplify horizontal construction and processing, and to achieve a greater damping effect than before when cutting the spool in the direction of operating the hydraulic motor. The object of the present invention is to provide a hydraulic control valve with high responsiveness, which can quickly return to its original state by freely discharging the oil, regardless of the magnitude of the damping effect.

In order to achieve the above object, in the hydraulic control valve of the present invention, the open side of the box-shaped spring receiver is arranged to face both ends of the spool, and the closed end face of the spring receiver is a throttle oil hole that is brought into contact with a wall surface of an oil chamber that is a pilot chamber of the spool and an end surface of the spool, and allows a damping oil chamber formed by the spring receiver and the end surface of the spool to pass through the oil chamber outside the spring receiver; The present invention is characterized in that the spring receiver is provided with a check valve that allows flow only from the damping oil chamber to the oil chamber outside the spring receiver.

An embodiment of the present invention will be described below with reference to FIG.

In the figure, the same reference numerals as in FIG. 2 indicate the same parts. Box-shaped spring receivers 19 and 19' are provided at both ends of the spool 5.
, 19' are connected to the spool chamber 17 and oil chamber 1 by springs 6, 6'.
0, 10' of the stepped portion 27 of the valve body 4.
, 27', respectively.

Damping oil chambers 23, 23' are located on the spool 5 side of the spring receivers 19, 19', and oil chambers 10, 23' are located on the spool 5 side of the spring receivers 19, 19'.
Check valve chambers 24, 24' are provided on the 10' side.
Also, the damping oil chambers 23, 23' are provided with spring receivers 19, 19.
The oil is communicated to the external oil chambers 10, 10' of the spring receivers 19, 19' through throttle oil holes 20, 20' provided in the outer circumferential direction of the spring receivers 19, 19', and the spring receivers 19 are connected to the check valve chambers 24, 24'.
, 19' are suitable for lotus oil due to the oil holes 22, 22' provided in the wisteria direction. Furthermore, the check valve chambers 24, 24' and the oil chamber 10
, 10' are separated by partition plates 25, 25' provided with oil holes.

Steel balls 21, 21' for opening and closing the oil holes 22, 22' are housed in the check valve chambers 24, 24'. That is, the steel balls 21, 21' are the valve bodies of the check valve. When the hydraulic switching valve 2 is switched from the neutral position to the 1 position and the pressure oil discharged from the hydraulic pump is guided to the input pipe 8, the pressure oil pushes and moves the povet valve 7 and flows from the output pipe 9 to the hydraulic motor 3. supplied to

At the same time, pressure oil also enters the oil chamber 10 through the oil passage 11. The pressure oil acting on the oil chamber 10 flows into the oil hole 22 due to the pressure oil.
Since it is blocked by the steel ball 21, it flows into the damping oil chamber 23 through the throttle oil hole 20, and the spool 5 slides to the right due to the pressure oil in the damping oil chamber 23, which is subjected to a large damping action. When the supply of pressure oil to the input pipe line 8 is cut off by operating the hydraulic cutoff valve 2, the spool 5 is moved by the spring 6.
The reaction force ′ returns it to the central position shown in the figure. In this case, the oil acting on the left end of the spool 5, that is, the damping oil chamber 23, pushes down the steel ball 21, returns to the oil chamber 101 through the oil hole 22 and the partition plate 25, regardless of the resistance of the throttle oil hole 20, and the spool 5 also returns. Returns to center position without receiving damping action.

Even when the hydraulic switching valve 2 is switched to the mountain position, the same operation as described above is performed.

As explained above, according to the hydraulic control valve of the present invention,
Since the damping mechanism is constituted by a copying receiver with a throttle oil hole, the end face of the spool, and the inner wall face of the valve body, there is no sliding surface that requires clearance management, and the structure and processing are simple.

In addition, when the spool is activated in the direction of operating the hydraulic motor, a damping effect is immediately obtained, so a large damping effect can be achieved. Due to the function of the check valve, the oil can be quickly returned to normal condition by freely discharging the oil regardless of the magnitude of the damping effect, so that high responsiveness can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a pressure oil system incorporating a hydraulic control valve according to the present invention, and FIG. 2 is a diagram showing a pressure oil system incorporating a conventional hydraulic control valve. 1...Hydraulic pump, 2...Hydraulic switching valve, 3...Hydraulic motor, 4...Valve body, 5...Spool, 6, 6'16, 16' ...Spring, 7,7'...
Povet valve, 10, 10'...Oil chamber, 11, 1
1'... Oil path, 12, 12', 13, 13'...
... Oil groove, 15 ... Oil tank, 17 ... Subur room,
18, 18', 19, 19'... Spring receiver, 20, 20
'... Squeezing oil hole, 21, 21'... Steel ball, 22, 22'
...Oil hole, 23, 23'... Damping oil chamber, 24, 24'... Check valve chamber, 25, 25'...
...Partition plate, 27, 27'...Stepped part. Figure 1 Figure 2

Claims (1)

[Claims] 1. A spool chamber in which two input pipes each connected to a hydraulic pump or an oil tank and two output pipes connected to a hydraulic motor are opened, and an input pipe that is slidably housed in the spool chamber and a spool equipped with an oil groove for communicating the pipe line and the output pipe line and a poppet valve that allows inflow only from the input pipe line to the output pipe line; and an oil chamber disposed at each end of the spool in the spool chamber; A hydraulic control valve equipped with an oil passage connecting an oil chamber to a hydraulic pump or an oil tank, and a spring inserted into the oil chamber to press the spool toward the center via a spring receiver, which is formed into a box shape. The opening side of the spring receiver is arranged to face the end face of the spool, and the open end face of the spring receiver is brought into contact with the wall surface of the oil chamber and the end face of the spool, and the spring receiver and the spool are A throttle oil hole that communicates a damping oil chamber formed by an end face of the damping oil chamber with the oil chamber outside the spring receiver, and a check valve that allows flow only from the damping oil chamber to the oil chamber outside the spring receiver are provided in the spring receiver. A hydraulic control valve characterized by being provided with.