JPH0424564B2 - - Google Patents

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention relates to an origin return device in an automatic reciprocating cylinder device, specifically, a home return device in an automatic reciprocating cylinder device such as a bolt, nut tightener, rock drill, etc. Regarding a return device.

[Problems to be solved by conventional technology and invention]

Conventionally, prior art similar to this type of automatic reciprocating cylinder device is disclosed in Japanese Patent Publication No. 58-24645,
58-44888 and the like.

These are activated by the interaction between a spool that receives constant pressure and alternating pressure from both sides in the pilot valve, and an actuating piston that receives constant pressure and alternating pressure from both sides in the cylinder. The piston is designed to automatically reciprocate.

However, in this case, the stopping positions of the working pistons are uneven when the pressure oil supply is stopped, and there is residual pressure. It is unsuitable for applications where it is required to always return to the home position, to eliminate residual pressure, and to be able to easily remove it from the bolt etc. each time work is completed.

The object of the present invention is to improve the conventional automatic reciprocating cylinder device so that the working piston can return to its home position at will.

[Means to solve the problem]

The present invention will now be described with reference to the accompanying drawings.

This device consists of an interaction between a spool 2 in a pilot valve 1 which receives constant pressure and alternating pressure from both sides, and an actuating piston 4 which receives constant pressure and alternating pressure from both sides in a cylinder 3. The actuating piston 4 is automatically reciprocated by the alternating pressure chamber 2 of the spool 2.
In an automatic reciprocating cylinder device in which the actuating piston 4 is returned to the home position when the pressure inside a decreases, the inside of the alternating pressure chamber 2a is communicated with a drain oil tank or the like through an open passage 5, Moreover, the opening passage 5 can be opened and closed by the forward and backward movement of the screw rod, and the working piston 4 is returned to its origin by opening the opening passage 5 and sliding the spool 2 by the forward and backward movement of the screw rod. This is an origin return device in an automatic reciprocating cylinder device, characterized in that it is configured as follows.

[Effect]

When the opening path is opened by moving the screw rod back and forth, the spool inside the pilot valve slides, and the working piston inside the cylinder returns to its home position.

〔Example〕

Furthermore, preferred embodiments of the present invention are illustrated in FIGS. 1 to 3.
This will be explained in detail with reference to the drawings.

In the figure, 1 is a pilot valve, 2 is a spool slidably built into the pilot valve 1, and 6 is a supply/discharge chamber consisting of an annular groove formed in the middle of the spool 2.

7 is a small diameter operating rod that presses one end of the spool 2.

2a and 2b are an alternating pressure chamber and a constant pressure chamber that introduce pressure oil into the other end of the spool 2 and the end face of the small diameter operating rod 7, respectively.

The pilot valve 1 is attached to the cylinder 3, and the side wall of the pilot valve 1 has an oil supply hole 8 and a communication hole 9.
When the spool 2 moves to the right, the oil supply hole 8 and the communication hole 9 communicate with each other through the supply and discharge chamber 6, and when the spool 2 moves to the left, the supply and discharge chamber 6 communicates with each other. The drain hole 10 and the communication hole 9 are designed to communicate with each other through the hole.

The actuating piston 4 is slidably fitted into the cylinder hole 11 in the cylinder 3, and between the spool portion of the actuating piston 4 and the cylinder hole 11, there is an alternating pressure chamber 4a with a large pressure receiving area and an alternating pressure chamber 4a with a small pressure receiving area. A pressure chamber 4b is formed.

Inside the side wall of the cylinder 3, there is a communication port 12 that opens at the right end of the alternating pressure chamber 4a, an oil supply port 13 that opens at the left end of the constant pressure chamber 4b, and an oil drain port 14 in the middle part.
and a pilot port 15, and a communication ring groove 16 is formed in the spool portion of the operating piston 4, so that when the operating piston 4 moves to the right, the communication port 1
2, the oil filler port 13, and the pilot port 15 are opened, and the oil drain port 14 is closed by the spool portion. When the working piston 4 moves to the left, the communication port 12 and the oil filler port 13 are opened, and the pilot port 15 and the oil drain port 14 are closed. Mouth 14
are designed to open and communicate through a communication ring groove 16.

Reference numeral 17 indicates an oil supply passage that communicates between the oil supply hole 8 and the oil supply port 13, 18 indicates a communication passage that communicates between the communication hole 9 and the communication port 12, and 19 indicates an oil drain passage that communicates between the oil drain hole 10 and the oil drain port 14. It is.

A pilot hole 20a communicates with the alternating pressure chamber 2a, and communicates with the pilot port 15 via a pilot passage 21.

22 is an oil supply pipe connection port, and 23 is an oil drain pipe connection port, which communicates with the oil supply hole 8 and the oil drain hole 10 through a supply oil passage 24 and a discharge oil passage 25, respectively.
2 and the constant pressure chamber 2b are communicated through a pilot hole 20b.

26 and 27 are position adjustment bolts for the spool 2, respectively.

5 is an open path, which connects the alternating pressure chamber 2a and the discharge oil path 25.
It can be opened and closed at the tip of a bolt 29 that is moved forward and backward by a return handle 28.

The opening/closing means for the open path 5 can be changed in design in place of the embodiment shown in the drawings.

Reference numeral 30 denotes a regulating valve that regulates the internal pressure of the constant pressure chamber 4b.

Since the present embodiment has the above configuration, the oil supply pipe connection port 22 and the oil drain pipe connection port 23 are connected to a hydraulic power source and a waste oil tank, etc. (not shown), respectively, and oil is supplied from the hydraulic source through the oil supply pipe connection port 22. When pressure oil is supplied to the hole 8, it is introduced into the constant pressure chamber 4b via the oil supply path 17 and the oil supply port 13, and on the other hand, is introduced into the constant pressure chamber 2b through the pilot hole 20b.

In the pilot valve 1, the spool 2 moves to the left, and in the cylinder 3, the working piston 4 begins to move to the right (FIG. 2).

At this time, the alternating pressure chamber 4a communicates with a drain oil tank (not shown) via the communication port 12, the communicating path 18, the communicating hole 9, the supply/discharge chamber 6, the drain oil passage 25, and the drain oil pipe connection port 22, and communicates with the alternating pressure The chamber 2a has a pilot hole 20a,
The oil drain port 14, the oil drain path 19, and the oil drain hole 1 are connected via the pilot passage 21, the pilot port 15, and the communication ring groove 16.
0, communicates with a drain oil tank (not shown) via a drain oil passage 25.

Thereafter, when the actuating piston 4 moves to the right and the pilot port 15 opens into the constant pressure chamber 4b, the pressure oil is introduced into the alternating pressure chamber 2a through the pilot port 15, the pilot passage 21, and the pilot hole 20a, and is then introduced into the small diameter actuating rod. Since the pressure receiving area of the alternating pressure chamber 2a is larger than that of the pressure receiving area 7, the spool 2 moves to the right (FIG. 1).

When the spool 2 moves to the right, the oil supply hole 8 and the communication hole 9 communicate with each other through the supply and discharge chamber 6, and the pressure oil passes through the communication hole 9, the communication path 18, and the communication port 12 into the alternating pressure chamber 4.
introduced into a.

Since the pressure receiving area of the working piston 4 in the alternating pressure chamber 4a is larger than the pressure receiving area of the working piston 4 in the constant pressure chamber 4b, the working piston 4 starts moving to the left.

In the process of moving the working piston 4 to the left,
The pilot port 15 is closed by the outer circumferential surface of the spool portion of the operating piston 4, and the pressure oil in the alternating pressure chamber 2a is sealed, so that the spool 2 is held in the right position, and then the communicating ring groove 16 is closed to the pilot port. When the right end of the communication ring groove 16 opens to the oil drain port 14, the sealing pressure oil in the alternating pressure chamber 2a flows through the pilot hole 20a and the pilot passage 2.
1. The communication ring groove 16, the oil drain port 14, the oil drain path 19, the drain hole 10, the oil drain path 25, and the oil drain pipe connection port 23 lead out to a drain tank (not shown), and the alternating pressure chamber 2a
As the internal pressure decreases, the spool 2 is moved to the left by the pressure oil in the constant pressure chamber 2b, and the communication path 18 of the cylinder 3 is blocked, so the oil supply pipe connection port 2
The pressure oil from 2 flows into the constant pressure chamber 4b through the oil supply hole 8 and the oil supply path 17, and the actuating piston 4 starts moving rightward under pressure from the pressure oil (second
figure).

Thereafter, the above operation is repeated.

Therefore, the interaction between the spool 2 in the pilot valve 1 and the working piston 4 in the cylinder 3 allows the working piston 4 to automatically reciprocate.

Next, in the case of a bolt tightening machine, etc., the bolt is tightened by the above-mentioned reciprocating motion, and the specified torque is reached, the pressure in the supply hydraulic circuit increases, and when this is detected by a pressure switch (not shown), the hydraulic pump stops. , the pressure oil supply stopped, and as a result of stopping the pressure oil supply,
When the working piston 4 is stopped during the movement process within the cylinder 3, in order to return the working piston 4 to the original position, turn the return handle 28 to retract the bolt 29 and open the open passage 5. This communicates the alternating pressure chamber 2a with a drain oil tank (not shown) (Fig. 3).

When the alternating pressure chamber 2a is communicated with a drain oil tank (not shown) in this way, the pressure in the alternating pressure chamber 2a decreases, and the spool 2 moves to the left due to the residual pressure of the pressure oil in the supply oil passage 24, etc. , and the internal pressure of the supply oil passage 24 decreases, the pressure switch detects this, the hydraulic pump is restarted, the supply of pressure oil is resumed, and the pressure oil enters the constant pressure chamber 2b and the constant pressure chamber 4b, As a result, the pressure oil in the alternating pressure chamber 4a of the cylinder 3 is led out to a drain oil tank (not shown), and the actuating piston 4 is returned to its original position and stopped.

At this time, even if pressure oil is continuously supplied, the constant pressure chamber 4b and the alternating pressure chamber 2a are in communication, but the open path 5 is in communication with a drain oil tank (not shown), so the spool 2 is It does not move to the right, and the actuating piston 4 does not move to the left.

When the actuating piston 4 is moved forward and backward, the return handle 28 is turned to advance the bolt 29 and the open passage 5 is closed.

〔Effect of the invention〕

As described above, the present invention communicates the inside of the alternating pressure chamber 2a of the pilot valve 1 with the drain oil tank etc. via the open passage 5, and enables the open passage 5 to be opened and closed.
Since the actuating piston 4 is configured to return to its home position optionally, it can be applied to applications where it is required to always return to the home position at the start of work and to eliminate residual pressure.

As described above, the intended purpose can be fully achieved.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, and FIGS. 1 to 3 are longitudinal sectional views. 1...Pilot valve, 2...Spool, 2a...
...Alternating pressure chamber, 3...Cylinder, 4...Working piston, 5...Open path.

Claims (1)

[Claims] 1. The actuating piston is activated by the interaction between a spool that receives constant pressure and alternating pressure from both sides in the pilot valve and an actuating piston that receives constant pressure and alternating pressure from both sides in the cylinder. In the automatic reciprocating cylinder device, the actuating piston is configured to automatically reciprocate, and when the pressure in the alternating pressure chamber of the spool decreases, the operating piston is at a return home position. Connects to drain oil tank, etc.
Further, the opening path can be opened and closed by the forward and backward movement of the screw rod, and the working piston is configured to return to its origin by opening the opening path and sliding the spool by the forward and backward movement of the screw rod. A home return device in an automatic reciprocating cylinder device, characterized in that: