JPH0130641Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of a hydraulic oscillator that vibrates a hydraulic piston through interaction between a directional control valve and a hydraulic piston.

As shown in FIG. 1, a conventional hydraulic oscillator has a piston 2 slidably installed in a cylinder 1, and a directional control valve 4 with a spool 3 slidably built into one side of the outer wall of the cylinder 1. Rod valves 5a and 5b of different diameters that operate the directional control valve 4 are brought into contact with both end surfaces of the spool 3, and a supply port 6 to which pressure oil from the outer wall of the cylinder 1 is supplied and a P port 7 of the directional control valve 4 are connected. and a pilot chamber 8b, which communicates with an oil chamber 9a formed by the cylinder 1 and the hydraulic piston 2,
Tank port 10 where oil on the outer wall of cylinder 1 is collected, T port 11 of directional control valve 4, cylinder 1
The A port 13 of the directional control valve 4 and the oil chamber 9b formed by the cylinder 1 and the hydraulic piston 2 are connected to each other, and the pilot chamber 8a and the inner peripheral wall of the cylinder 1 are connected to each other. An annular groove 15 is provided in the center of the hydraulic piston 2, and when pressure oil is supplied to the supply port 6, the pressure oil flows into the pilot chamber 8b, the P port 7, and the oil chamber 9a. Then, the hydraulic piston 2 slides to the right, and when the oil chamber 9a and the pilot port 14 communicate with each other, the pressure oil flows into the pilot chamber 8a, and the spool 3 flows into the pilot chamber due to the difference in area between the rod valves 5a and 5b. 8b slides to the right against the hydraulic pressure, the A port 13 and the P port 7 communicate, the pressure oil flows into the oil chamber 9b, and the oil chamber 9a and the oil chamber 9
Due to the difference in pressure receiving area b, the hydraulic piston 2 is in the oil chamber 9a.
When the piston 2 slides to the left against the hydraulic pressure of 3 slides to the left, A port 13 and T port 11
, the hydraulic pressure in the oil chamber 9b disappears, and the hydraulic piston 2 again slides to the right due to the hydraulic pressure in the oil chamber 9a. When pressure oil is supplied as described above, the hydraulic piston 2 vibrates due to the interaction between the directional control valve 4 and the hydraulic piston, and it is possible to change the vibration frequency and vibration energy depending on the supplied hydraulic pressure and the amount of oil. However, as is clear from the above-mentioned operation, the stroke of the hydraulic piston 2 is determined by the distance between the pilot port 14 and the oil chamber 9a for the right stroke, and the distance between the pilot port 14 and the annular groove 15 for the left stroke, and remains unchanged.

Therefore, it could not be used for applications requiring variable stroke.

The present invention improves the conventional hydraulic oscillator and provides a hydraulic oscillator whose stroke is also variable.

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

A hydraulic piston 2 is slidably provided in a cylinder 1, a directional switching valve 4 with a spool 3 slidably built in is provided on one outer wall of the cylinder 1, and a rod of different diameter is used to operate the directional switching valve 4. The valves 5a and 5b are brought into contact with both end surfaces of the spool 3, and the supply port 6 on the outer wall of the cylinder 1 to which pressure oil is supplied, the P port 7 of the directional control valve 4, the pilot chamber 8a, the cylinder 1 and the hydraulic piston 2 are connected. The tank port 10 and the T port 1 of the directional control valve 4 communicate with the formed oil chamber 9a and the oil on the outer wall of the cylinder 1 is collected.
1. T port 12 opened on the inner peripheral wall of cylinder 1
The A port 13 of the directional control valve 4 and the oil chamber 9 formed by the cylinder 1 and the hydraulic piston 2 communicate with each other.
b, and communicates the pilot chamber 8b with the left retraction limit port 16 opened in the inner peripheral wall of the cylinder 1 and the right retraction limit port 18 opened in the inner peripheral wall of the valve chamber 17 provided at the right end of the hydraulic piston 2. A main valve 22 is slidably provided in the valve chamber 17 and has a communication hole 21 that is constantly in communication with the right retraction limit port 18.
An adjustment bolt 24 for slidingly adjusting the main valve 22 is screwed onto the right end of the valve chamber 17, and a return spring 25 is attached to the main valve 22 to keep the right end of the main valve 22 and the end face of the adjustment bolt 24 in constant contact. An auxiliary valve 19 provided at the left end to detect the position of the hydraulic piston 2 is connected to the main valve 22.
A communication port 2 is provided to the auxiliary valve 19 so as to be slidable therein.
0, a return spring 26 for pushing the auxiliary valve 19 leftward is provided at the right end of the auxiliary valve 19, and the communication port 20 and the T port 12 are formed by the right end of the hydraulic piston 2 and the cylinder 1. They are communicated via the rear chamber 23.

In a hydraulic oscillator having such a configuration, when pressure oil is supplied to the supply port 6 provided on the outer wall of the cylinder 1, the P port 7 of the directional control valve 4 and the pilot chamber 8
Pressure oil flows into A and oil chamber 9a, and the spool 3 slides to the right due to the hydraulic pressure of pilot chamber 8a.
Port 13 and P port 7 communicate with each other, pressure oil flows into oil chamber 9b, and the hydraulic piston 2 slides to the left due to the difference in pressure receiving area between oil chambers 9a and 9b. 9b, the pressure oil supplied to the oil chamber 9b flows into the pilot chamber 8b through the left retreat limit port 16, and resists the hydraulic pressure in the pilot chamber 8a due to the difference in area between the rod valves 5a and 5b. spool 3 slides to the left, A port 13 and T port 11
and the oil chamber 9b communicates with T through the A port 13.
By communicating with the port 11, the hydraulic pressure in the oil chamber 9b disappears, and the hydraulic piston 2 slides to the right due to the hydraulic pressure in the oil chamber 9a. Near the right sliding end of the hydraulic piston 2, the auxiliary valve 19 is pressed against the right end of the hydraulic piston 2 by a return spring 26.
When the auxiliary valve 19 slides to the right and the communication port 20 of the auxiliary valve 19 communicates with the right retreat limit port 18 through the communication hole 21 of the main valve 22, the pilot chamber 8b moves to the right. The rear chamber 23 communicates with the T port 12 through the retraction port 18, communication hole 21, and communication port 20, the hydraulic pressure in the pilot chamber 8b disappears, and the spool 3 moves to the right due to the hydraulic pressure in the pilot chamber 8a. The hydraulic piston 2 slides to the left again. Return spring 2 together with hydraulic piston 2
6, the auxiliary valve 19 slides to the left, and the communication hole 21 of the main valve 22 and the communication port 20 of the auxiliary valve 19
When the hydraulic piston 2 further slides to the left, pressure oil flows into the pilot chamber 8b from the left retraction limit port 16 again, causing the spool 3 to reverse, and then the hydraulic piston 2 also reverses to the right. slide. By supplying pressure oil in this manner, the hydraulic piston 2 vibrates.

Furthermore, when the adjustment bolt 24 is screwed in and the main valve 22 is slid to the left, the communication port 20 of the auxiliary valve 19 that has been slid to the right together with the hydraulic piston 2 is connected to the main valve 2.
The timing at which the two communication holes communicate with each other becomes earlier than before, and on the other hand, by returning the adjustment bolt 24, the main valve 22 slides to the right due to the pressing force of the return spring 25, and the timing is delayed, and the adjustment Slide the main valve 22 with the bolt 24 and open the auxiliary valve 1.
The communication position between the communication port 20 of 9 and the right retraction limit port 18 is made variable, and the rod valve 5 has a large pressure receiving area.
The right retraction limit position of the hydraulic piston 2 is made variable by changing the timing at which oil is discharged from the pilot chamber 8b and by changing the timing at which the directional control valve 4 operates. As a result, the stroke of the hydraulic piston 2 can be adjusted using the adjustment bolt 24.

As mentioned above, the hydraulic oscillator of the present invention is an innovative product with a simple structure that allows stroke adjustment, which was impossible with conventional hydraulic oscillators, simply by adjusting the adjustment bolt. This greatly expands the applications of the machine.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a conventional hydraulic oscillator, and FIG. 2 is a sectional view of a hydraulic oscillator according to the present invention. 1...Cylinder, 2...Hydraulic piston, 3...
Spool, 4... Directional switching valve, 5a, 5b... Rod valve, 6... Supply port, 7... P port, 8a,
8b...Pilot chamber, 9a, 9b...Oil chamber, 1
0...tank port, 11,12...T port,
13...A port, 14...Pilot port,
15...Ring groove, 16...Left retraction port, 17...
... Valve chamber, 18 ... Right retraction limit port, 19 ... Auxiliary valve, 20 ... Communication port, 21 ... Communication hole, 22
...Main valve, 23...Rear chamber, 24...Adjustment bolt,
25, 26...Returning springs.

Claims (1)

[Scope of utility model registration request] A hydraulic piston is slidably provided in the cylinder, the cylinder and the hydraulic piston form oil chambers with different pressure receiving areas, and a directional control valve with a spool slidably built in is provided on the outer wall of one side of the cylinder. Rod valves with different diameters that actuate the directional control valve are brought into contact with both end faces of the spool, and high pressure oil is constantly loaded into the oil chamber with a small pressure receiving area and the rod valve with a small diameter, and the end of the stroke of the hydraulic piston is An oil passage is configured so that oil is supplied and discharged from the back of a rod valve with a large diameter in the vicinity of the valve to operate a directional control valve, and the operation of the directional control valve supplies and discharges oil to an oil chamber with a large pressure-receiving area. In a hydraulic oscillator that vibrates a hydraulic piston through interaction between a directional control valve and a hydraulic piston, the rod valve with a large pressure receiving area is used to operate the directional control valve and regulate the rightward retraction limit position of the hydraulic piston. A right retraction limit port communicating with the back surface of the hydraulic piston is provided in a valve chamber provided at the right end of the hydraulic piston, and a main valve having a communication hole that is constantly in communication with the right retraction limit port is slidably provided in the valve chamber. , an adjustment bolt for slidingly adjusting the main valve is screwed onto the right end of the valve chamber, the right end of the main valve and the end face of the adjustment bolt are always in contact with each other, and an auxiliary valve for detecting the position of the hydraulic piston is connected to the main valve. A communication port is provided on the auxiliary valve, a spring is provided on the right end of the auxiliary valve that presses the auxiliary valve to the left, and the auxiliary valve is moved by the hydraulic piston near the right sliding end of the hydraulic piston. After sliding it to the right, connect the communication port of the auxiliary valve with the communication hole of the main valve, and drain the oil from the back of the rod valve, which has a large pressure receiving area, through the right retraction port, the communication hole, and the communication port. The main valve is configured to form an oil path for discharging the oil, and the auxiliary valve is configured to slide to the left by the pressing force of the spring in response to the reversal of the hydraulic piston to shut off the oil path. By sliding the adjustment bolt, the communication position between the communication port of the auxiliary valve and the right retraction limit port can be varied, and the timing at which oil is discharged from the back of the rod valve, which has a large pressure receiving area, can be changed, and the directional control valve can be adjusted. A hydraulic oscillator characterized in that the right retraction limit position of a hydraulic piston is made variable by changing the operating timing.