JP3479476B2 - Booster type hydraulic cylinder device with lock mechanism - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a booster type fluid pressure cylinder device for adding a fluid pressure acting force acting on a plurality of pressure receiving surfaces to obtain a thrust force. The present invention relates to a booster type fluid pressure cylinder device having a mechanism for locking a cylinder at the stroke end.

[0002]

2. Description of the Related Art A booster type fluid pressure in which a plurality of pressure receiving surfaces for exerting a fluid pressure such as air pressure or hydraulic pressure are provided and a large thrust force is obtained by adding fluid pressure acting forces acting on these pressure receiving surfaces. As a cylinder device, for example, JP-A-11-939
The one described in Japanese Patent No. 12 is known. This is such that an outer piston is slidably accommodated in a cylinder hole inside a casing, a cylindrical large-diameter outer rod is connected to the outer piston, and an inner piston is relatively disposed inside the outer rod. The inner piston is slidably accommodated and is fixed to one end of the casing by an inner rod penetrating the outer piston. Then, these outer pistons and outer rods are driven by a large thrust obtained by adding the pneumatic force acting on the pressure receiving surface at one end of the outer piston and the pressure receiving surface on the inner surface of the distal end portion of the outer rod, thereby increasing the It is for carrying loads.

In such an air cylinder device, the outer rod or the outer piston is stroked so as not to be unintentionally retracted by a large load when the outer rod is stopped at the forward position. It is desirable to provide a locking mechanism to lock the end. However, since the air cylinder device has a special structure, the lock mechanism used in a normal air cylinder, for example, Jikken 61-1.
In this booster type air cylinder device, there is provided a lock mechanism of a type in which a lock piston is moved forward and backward by a pneumatic force and a spring force to engage with and disengage from a groove on the outer circumference of a rod as described in Japanese Patent No. 6412. It cannot be diverted as it is.

[0004]

SUMMARY OF THE INVENTION The main technical problem of the present invention is to provide a booster type fluid pressure cylinder device having a special configuration different from that of a conventional fluid pressure cylinder, and a locking mechanism adapted to the configuration. Is provided so that the piston can be reliably locked at the stroke end.

Another technical problem of the present invention is that the lock piston, which moves forward and backward by the fluid pressure acting force and the spring force, engages with and disengages from the outer piston, drives the outer piston and the outer rod. By not being affected by the fluid pressure supplied to the cylinder device,
The purpose of this is to prevent the lock piston from malfunctioning and improve the locking accuracy.

[0006]

In order to solve the above-mentioned problems, a booster type air cylinder device of the present invention comprises a casing having a cylinder hole therein and an outer piston slidably accommodated in the cylinder hole. And a cylindrical outer rod whose distal end extends from the casing and whose distal end is connected to the outer piston and whose distal end is closed by a tube head, and which is relatively slidable inside the outer rod. It is made as housing, an inner piston which is fixed to one end of the casing by the inner rod penetrating the outer piston, the Autapisu
A first pressure chamber for exerting a fluid pressure on the base end side of the ton;
It is installed between the tube head and the inner piston.
A second pressure chamber for exerting fluid pressure on the tube head;
Installed between the inner and outer pistons
A third pressure chamber, a plurality of ports for supplying pressure fluid to the first to third pressure chambers, and a lock mechanism for locking the outer piston at the stroke end,
The lock mechanism includes a piston holder attached to a side surface of the casing, a lock piston slidably accommodated in the piston holder, and a tip extending from the lock piston and having a tip at an inner peripheral surface of the casing and an outer peripheral surface of the outer piston. A lock shaft that projects into the space between the lock piston and the lock piston that engages and disengages with a recess on the outer piston outer periphery when the lock piston moves forward and backward; a lock spring that biases the lock piston toward the lock position; A first lock pressure chamber formed on one side of the lock piston and communicating with one of the ports to apply a fluid pressure in the unlocking direction to the lock piston, and a second lock pressure chamber formed on the other side of the lock piston. A communication hole that is formed inside the lock piston and the lock shaft and that communicates the second lock pressure chamber with the void portion. And the void portion is the Autapi
Lock that locks the locking member to prevent the rotation of the stone
It is electrically connected to the first pressure chamber through a groove, and the second pressure chamber is connected to the second pressure chamber .
The pressure receiving area of the lock piston in the lock pressure chamber and the pressure receiving area of the tip of the lock shaft in the void are
Surface where the air pressure acting on each other cancels each other
It is characterized by being a product .

In the fluid pressure cylinder device of the present invention having the above structure, when the pressure fluid is not supplied from the port to the first lock pressure chamber on one side of the lock piston,
The lock piston moves forward to the lock position by the elastic force of the lock spring, and the tip of the lock shaft locks in the recess of the outer piston outer periphery to lock the outer piston at the stroke end.

When pressure fluid is supplied from the port to the first lock pressure chamber from this state, the lock piston retracts while compressing the lock spring and the lock shaft disengages from the recess, so that the outer piston slides. It becomes possible.

Here, in the above-mentioned booster type fluid pressure cylinder device, due to its structure, the pressure fluid in the pressure chamber flows into the space between the inner peripheral surface of the casing and the outer peripheral surface of the outer piston. Therefore, there is a possibility that the lock shaft is pushed in the unlocking direction by the fluid pressure acting on the tip end surface of the lock shaft, the elastic force of the lock spring is diminished, and the lock becomes impossible. However, in the present invention, the second lock pressure chamber is provided on the surface of the lock piston opposite to the first lock pressure chamber, and the second lock pressure chamber and the void are communicated with each other by the communication groove. Since the fluid pressure acting force in the unlocking direction that acts on the tip end surface of the lock shaft in the void portion is offset by the fluid pressure acting force in the lock direction that acts on the lock piston in the second lock pressure chamber, Such a problem does not occur, malfunction of the lock piston is prevented, and locking accuracy is improved.

According to a preferred specific embodiment of the present invention, the pressure receiving area of the lock piston in the second lock pressure chamber is substantially equal to or slightly larger than the pressure receiving area of the tip of the lock shaft in the void. , To these
The respective pneumatic forces exerted cancel each other out .

[0011]

1 and 2 show a preferred representative embodiment of a fluid pressure cylinder device according to the present invention, in which an air cylinder device using compressed air as a pressure fluid is shown. This air cylinder device has a casing 1. This casing 1 is composed of a cylinder tube 1a having a substantially square cross section and a circular cylinder hole 2 inside, a head cover 1b attached to the base end side thereof, and a rod cover 1c attached to the tip end side. Has been done.

An outer piston 3 is slidably accommodated in the cylinder hole 2, and the outer piston 3
A base end portion of a cylindrical large-diameter outer rod 4 is attached to the. The tip of this outer rod 4 is
Bearing member 5 provided on the inner peripheral surface of the rod cover 1c
And a seal member 6 slidably supported by the casing 1
Of the tube, and its tip is airtightly closed by the tube head 7.

On the inner side surface of the head cover 1b, the base end portion of the inner rod 8 is fixed to the central portion thereof. The inner rod 8 is the same as the outer piston 3 described above.
The inner piston 9 extends through the outer rod 4 so as to be airtight and slidably penetrated through the center of the inner piston 9
Are attached so as to be slidable relative to the outer rod 4.

Therefore, the inner rod 8 and the inner piston 9 are in an integral relationship with the casing 1, while the outer piston 3 and the outer rod 4 are opposed to each other.
Are integrally connected to each other and slide with respect to the casing 1, the inner rod 8 and the inner piston 9.

On the side of the head cover 1b, two ports 10a and 10b for supplying compressed air are formed on a port block 18 attached to the head cover 1b. Of these, the first port 10a communicates with the first pressure chamber 14 between the head cover 1b and the outer piston 3 by the flow passage 12a, and the inner piston 9 passes through the flow passage 12b formed inside the inner rod 8.
To the second pressure chamber 15 between the tube head 7 and the tube head 7. Further, the second port 10b is connected to the third pressure chamber 16 between the outer piston 3 and the inner piston 9 through the flow passage 13a and the flow passage 13b formed in the inner rod 8.
Is in communication with.

Therefore, when compressed air is supplied to the first pressure chamber 14 and the second pressure chamber 15 from the first port 10a,
The outer piston 3 and the outer rod 4 move forward by the pneumatic force acting on the pressure receiving surface 3a of the outer piston 3 and the pressure receiving surface 7a of the tube head 7, and stop at the forward stroke end shown in FIG. At this time, the thrust of the outer rod 4 is the sum of the air pressure acting forces acting on the pressure receiving surface 3a of the outer piston 3 and the pressure receiving surface 7a of the tube head 7, so that the thrust force is larger than that of a normal cylinder having only one piston. And large thrust can be obtained. When compressed air is supplied to the third pressure chamber 16 from the second port 10b, the outer piston 3 and the outer rod 4 retract from the positions shown in the figure.

Reference numeral 20 in the figure denotes a rotation preventing mechanism for preventing the rotation of the outer piston 3, which includes a locking groove 21 cut axially in the inner surface of the cylinder tube 1a and the outer piston 3. A locking member 22 is attached to the outer peripheral surface and slidably fits in the locking groove 21.

The air cylinder device is also equipped with a lock mechanism 24 for locking the outer piston 3 at the forward stroke end. As shown in FIGS. 3 and 4, the lock mechanism 24 includes a piston holder 25 attached to the outer surface of the casing 1.
The lock piston 26 is housed inside the piston holder 25 so as to be movable forward and backward in a direction orthogonal to the axis of the outer piston 3.

The lock piston 26 integrally has a lock shaft 26a whose tip extends from the piston holder 25 into a space 29 between the inner peripheral surface of the casing 1 and the outer peripheral surface of the outer piston 3. The forward and backward movement of the lock piston 26 causes the tip of the lock shaft 26a to be engaged with and disengaged from the recess 27 formed on the outer circumference of the outer piston 3. The lock spring 2 is provided between the top of the lock piston 26 and the piston holder 25.
8 is provided, and the lock piston 28 is elastically ejected by the lock spring 28 in the forward direction (lock direction).

Two lock pressure chambers 31, 32 are formed on both sides of the lock piston 26. Of these, the first lock pressure chamber 31 is connected to the pipe 33.
It is communicated with the second port 10b by the inner flow path 33a, and when the outer piston 3 is driven in the backward direction, the compressed air is supplied from the second port 10b to the lock piston 26 in the unlocking direction (the backward direction). Direction) acting force is generated. One of the second lock pressure chambers 32 communicates with the space 29 between the inner peripheral surface of the casing 1 and the outer peripheral surface of the outer piston 3 through a communication hole 34 formed inside the lock piston 26 and the lock shaft 26a. ing. The pressure receiving area of the pressure receiving surface 26c of the lock piston 26 facing the second lock pressure chamber 32 and the pressure receiving surface 2 of the tip end of the lock shaft 26a in the void portion 29.
The pressure receiving area of 6d is formed to have a size close to each other. Preferably, the pressure receiving area of the pressure receiving surface 26c is substantially equal to or slightly larger than the pressure receiving area of the pressure receiving surface 26d. Accordingly, the air pressure acting force in the unlocking direction that acts on the tip end surface 26d of the lock shaft 26a in the gap 29 is the same as the air pressure acting in the lock direction that acts on the pressure receiving surface 26c of the lock piston 26 in the second lock pressure chamber 32. It can be offset by acting force.

Next, the operation of the lock mechanism 24 will be described. 1 and 3 show the first port 10a to the first port.
Compressed air is supplied to the pressure chamber 14 and the second pressure chamber 15,
The third pressure chamber 16 is shown open to the atmosphere through the second port 10b, and the outer piston 3 and the outer rod 4 are at the forward stroke end. On the other hand, in the lock mechanism 24, since the first lock pressure chamber 31 is open to the atmosphere through the second port 10b, the lock piston 26 advances to the lock position by the urging force of the lock spring 28, and the tip end of the lock shaft 26a. Is locked in the recess 27 on the outer surface of the outer piston 3 and
Is locked. At this time, the compressed air in the first pressure chamber 14 flows into the space 29 between the inner peripheral surface of the casing 1 and the outer peripheral surface of the outer piston 3 through the locking groove 21 of the rotation preventing mechanism 20, Tip surface 2 of lock shaft 26a
Air pressure in the direction of retracting the lock shaft 26a acts on 6d. However, in the second lock pressure chamber 32 that communicates with the gap 29 and the communication hole 34, the air pressure acting force in the direction of advancing it to the lock piston 26 acts, so that the acting forces in both directions cancel each other out. Therefore, the lock piston 26 is not affected by the air pressure flowing into the gap 29.

From the above-mentioned state, the second port 10b
Compressed air is supplied to the third pressure chamber 16 and the first lock pressure chamber 31 from the first pressure chamber 14 and the second pressure chamber 15.
When opened to the outside through the port 10a, the volume of the first lock pressure chamber 31 is smaller than that of the third pressure chamber 16,
As shown in FIG. 4, first, the lock piston 26 retracts to release the lock of the outer piston 3 by the lock shaft 26a, and immediately thereafter, the outer piston 3 starts retracting and moves to the retract stroke end.

In the present invention, it goes without saying that hydraulic pressure can be used as fluid pressure.

[0024]

As described above, according to the present invention, the outer piston in the booster type air cylinder device having a special structure different from the ordinary air cylinder can be reliably locked at the stroke end thereof. . In particular, the lock piston that engages and disengages with the outer piston is prevented from being affected by the air pressure supplied to the air cylinder device for driving the outer piston and the outer rod, thereby preventing the lock piston from malfunctioning. You can prevent it and improve the locking accuracy.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is a plan view of FIG.

FIG. 3 is an enlarged view of a main part of FIG.

FIG. 4 is an enlarged cross-sectional view at the same position as in FIG. 3 showing a different operation state.

[Explanation of symbols]

1 casing 2 cylinder holes 3 outer piston 3a Pressure receiving surface 4 Outer rod 7 tube head 7a Pressure receiving surface 8 Inner rod 9 Inner piston 10a, 10b ports 14,15,16 Pressure chamber 24 Lock mechanism 25 piston holder 26 Lock piston 26a Lock shaft 28 Lock spring 29 Void 31 1st lock pressure chamber 32 Second lock pressure chamber 34 communication hole

Claims (2)

(57) [Claims] 1. A casing having a cylinder hole therein, an outer piston slidably accommodated in the cylinder hole, a base end portion of which is connected to the outer piston, and a front end portion of which extends from the casing. A cylindrical outer rod whose tip is closed by a tube head and a slidable inner rod are housed so as to be relatively slidable, and fixed to one end of the casing by an inner rod penetrating the outer piston. Fluid pressure is applied to the inner piston and the base end of the outer piston.
The first pressure chamber, the tube head and the inner pipe
Installed between the stones to exert fluid pressure on the tube head
The second pressure chamber to be driven, the inner piston and the outer
The third pressure chamber provided between the pistons and the first to third
A piston holder having a plurality of ports for supplying pressure fluid to the third pressure chamber and a lock mechanism for locking the outer piston at the stroke end, the lock mechanism being attached to a side surface of the casing. And a lock piston slidably accommodated inside the piston holder, and a tip extending from the lock piston and projecting into a gap between the inner peripheral surface of the casing and the outer peripheral surface of the outer piston to move the lock piston forward and backward. A lock shaft that engages and disengages with a recess on the outer circumference of the outer piston, a lock spring that biases the lock piston toward the lock position, and a lock spring that is formed on one side of the lock piston and communicates with one of the ports. First lock pressure chamber for applying a fluid pressure in the unlocking direction to the lock piston, and formed on the other side of the lock piston Second lock pressure chamber and a communication hole formed inside the lock piston and the lock shaft for communicating the second lock pressure chamber with the void portion, and the void portion has the outer pin.
Lock that locks the locking member to prevent the rotation of the stone
It is electrically connected to the first pressure chamber through a groove, and the second pressure chamber is connected to the second pressure chamber .
The pressure receiving area of the lock piston in the lock pressure chamber and the pressure receiving area of the tip of the lock shaft in the void are
Surface where the air pressure acting on each other cancels each other
A booster type fluid pressure cylinder device equipped with a lock mechanism characterized by being a product . 2. The fluid pressure cylinder device according to claim 1, wherein the pressure receiving area of the lock piston in the second lock pressure chamber is substantially equal to or slightly larger than the pressure receiving area of the tip of the lock shaft in the void. These
It is characterized by the fact that the respective air pressure acting forces on each other cancel each other out .