JPH09137802A - Automatic reciprocating cylinder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an automatic reciprocating cylinder by which inner/outer double rods are operated at a prescribed timing respectively. SOLUTION: An inner rod 11 with a piston and an outer rod 12 with a piston 27 are installed slidably in a casing 14 and supply/exhaust air flow passages 47, 48 are connected to a retreat side pressure room 28a and a forward side pressure room 28b respectively. The retreat side pressure room 28a is communicated with the forward side pressure room of the piston of the inner rod 11 by a bypass flow passage 54 and the forward side pressure room 28b is communicated with the retreat side pressure room of the piston of the inner rod 11 by a bypass flow passage 17a (clearance). When the outer rod 12 is positioned to a forward side position and the retreat side position, the inner rod 11 is operated by following this.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic reciprocating cylinder in which an inner rod and an outer rod which are double in inner and outer sides are continuously reciprocated separately.

[0002]

2. Description of the Related Art A clamp member is used to move an object in a straight line in a grasped state and release the grasped state when the object is moved to a predetermined position. In order to operate such a clamp member, it is necessary for the clamp member to perform the opening / closing operation and the advancing / retreating operation.

When an electric motor is used to perform such an operation, the control is complicated because the clamp advancing / retracting operation and the clamp opening / closing operation are performed at a predetermined timing, and the manufacturing cost of the apparatus increases. I will end up.

[0004]

Therefore, the inventor has studied that the forward / backward movement and the opening / closing operation of the clamp member are performed by using a pneumatic cylinder. When the rod is reciprocated by a pneumatic cylinder, a single-acting or double-acting type cylinder is usually used.In the case of the double-acting type, the rod forward side pneumatic chamber and the rod backward side pneumatic chamber are A switching valve is used to alternately supply air pressure to the.

Therefore, in order to axially reciprocate the inner rod and the outer rod having the double structure of the inside and the outside by the pneumatic cylinder, the electromagnetic force is controlled in order to control the supply of the pneumatic pressure into the pneumatic chamber corresponding to each rod. Since the number of valves increases, it is necessary to provide a control unit that operates each solenoid valve at a predetermined timing in order to continuously or sequentially operate each rod at a predetermined timing.

It is an object of the present invention to provide an automatic reciprocating cylinder that operates double rods inside and outside at predetermined timings.

[0007] The above and other objects and novel features of the present invention will become apparent from the description of the present specification and the accompanying drawings.

[0008]

SUMMARY OF THE INVENTION Among the inventions disclosed in the present application, the outline of a representative one will be briefly described.
It is as follows.

That is, the automatic reciprocating cylinder of the present invention is a casing in which an inner rod having a first piston and an outer rod having a second piston and through which the inner rod penetrates are axially slidably provided. And the second
Flow passage switching means that is connected to two supply / exhaust passages that are respectively connected to the forward pressure chamber and the backward pressure chamber that are formed on both sides of the piston, and that connect these supply / exhaust passages to the intake port and the exhaust port. And a first bypass flow passage that connects one of the forward-side pressure chamber and the backward-side pressure chamber formed on both sides of the first piston to one of the forward-side pressure chamber and the backward-side pressure chamber formed on both sides of the second piston. And a second bypass flow passage communicating the other of the forward pressure chamber and the backward pressure chamber formed on both sides of the first piston with the other of the forward pressure chamber and the backward pressure chamber formed on both sides of the second piston. And when the second piston is located at either the forward limit position or the backward limit position, the first piston is provided via one of the forward pressure chamber and the backward pressure chamber formed on both sides of the second piston. Formed on both sides of the piston The fluid was supplied to one of the forward side pressure chamber and the backward side pressure chamber, characterized in that as actuating the inner rod subsequent to transfer to the forward limit and the backward limit position of the outer rod.

When the inner rod reaches the forward limit position and the backward limit position, the connection of the air supply port is switched to one of the pressure chambers on both sides of the piston of the outer rod. When the outer rod reaches the forward limit position and the backward limit position, one of the pressure chambers on both sides of the inner piston communicates with the air supply port via one side of the pressure chamber on both sides of the piston of the outer rod. As a result, when the fluid is supplied to the air supply port, the inner rod and the outer rod operate continuously in a predetermined order.

When the inner rod reaches the forward limit position, one of the two air supply / exhaust passages communicates with the air supply port, and when the inner rod reaches the backward limit position, the other of the two air supply / exhaust passages and the air supply port. The flow path switching means communicating with the port may be attached to the inner rod, or the flow path switching means may be formed by an electromagnetic valve provided outside.

[0012]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIGS. 1 (a) to 1 (d) are views showing a state of forward / backward movement and opening / closing movement of a clamper 1 for gripping an object and an opening / closing member 2 for opening / closing the clamper. The clamper 1 has a tweezers shape, has an elastic force in a spreading direction by itself, and is attached to the inner member 1a. The opening / closing member 2 is attached to an outer member (not shown) that is located outside the inner member 1a and is slidably fitted in the inner member 1a.

FIG. 1A shows a state in which the clamper 1 is at the retracted limit position and is closed by the opening / closing member 2. Under this condition, when the outer member is moved backward with respect to the inner member 1a, the opening / closing member 2 is moved backward and the clamper 1 is opened, as shown in FIG. 1 (b). Under this state, when the inner member 1a is advanced, the clamper 1 moves forward with the open state as shown in FIG. 1C, and the forward movement causes the clamper 1 to move to a position where it grasps an object. Become.

Then, as shown in FIG. 1D, when the opening / closing member 2 is moved forward through the outer member, the opening / closing member 2 is moved.
The clamper 1 is closed by and the object is gripped by the clamper 1. After that, when the inner member 1a is moved backward, it returns to the state shown in FIG.

3 to 5 show a pneumatic cylinder 13 having an inner rod 11 for driving such an inner member 1a and an outer rod 12 for driving an outer member. 2 shows its external appearance, FIG. 3 shows an enlarged internal structure of the first half of the pneumatic cylinder 13, and FIG. 4 shows an enlarged internal structure of the latter half of the pneumatic cylinder 13.

The pneumatic cylinder 13 has a head block 14a on the front end side thereof, an end block 14b on the rear end side thereof, and a cover tube 14c for fixing the head block 14a on the rear end side thereof. As shown in FIG. 5, the cover 15 has a hexagon socket head cap screw 1
6 fixed.

A first tube 21 is attached between the cylinder block 17 fixed to the head block 14a and the cylinder block 18 fixed to the end block 14b, and the first tube 21 is provided outside the first tube 21. The second tube 22 is fixed via a predetermined gap. Further, a third tube 23 is fixed to the head block 14a and the end block 14b with respect to the second tube 22 with a predetermined gap. This third
A predetermined gap is formed between the tube 23 and the cover tube 14c.
The casing 14 is formed by a, the end block 14b, the cover tube 14c, and the three tubes 21 to 23. Tube 1 forming casing 14
4c and 21 to 23 are fourfold.

The inner rod 1 is provided at the center of the casing 14.
1 is provided slidably in the axial direction.
The piston 24 provided in No. 1 is located in the pneumatic chamber 25 formed in the first tube 21. This pneumatic chamber 2
In FIG. 4, the piston 5 is divided into a retreating side pressure chamber 25a on the left side and a forward side pressure chamber 25b on the right side in FIG. Therefore, when the compressed air is supplied into the backward pressure chamber 25a, the inner rod 11 moves backward and the forward pressure chamber 25a.
If it is supplied into b, it will move forward. FIG.
The state where the inner rod 11 is in the backward limit position is shown.

A fixed cylinder 26 is screwed to the head block 14a at the tip of the casing 14, and the outer rod 12 is axially slidably mounted between the fixed cylinder 26 and the inner rod 11. Has been done. A hollow piston 27 is provided on the outer rod 12, and the piston 27 is located in an air pressure chamber 28 formed by the fixed cylinder 26 and the head block 14a.

The air pressure chamber 28 is divided by the piston 27 into a rearward-side pressure chamber 28a on the left side and a forward-side pressure chamber 28b on the right side in FIG. Therefore, when the compressed air is supplied into the backward side pressure chamber 28a, the outer rod 12
Moves backward, and when supplied to the forward pressure chamber 28b, moves forward. FIG. 3 shows a state in which the outer rod 12 is at the forward limit position.

A sleeve 31 is provided axially slidably in the accommodation hole formed in the end cover 15, and an annular support member 30 is fixed in the accommodation hole formed in the end block 14b. A sleeve 32 is provided in the annular support member 30 so as to be slidable in the axial direction. And
A flow path switching tube 33 is screwed to both sleeves 31 and 32 at both ends thereof. These sleeves 3
A channel switching member 34 is formed by the channels 1, 32 and the channel switching tube 33.

The rear end portion of the inner rod 11 is located in the flow path switching tube 33 with a gap, and the inner rod 1
A large-diameter abutting member 36 is screwed to the rear end portion of the screw 1. When the inner rod 11 moves to the retracted limit position as shown in FIG. 4, the contact member 36 contacts the stopper surface 31a of the sleeve 31 to reach the retracted limit position, and the flow path switching member 3
4 is set to the backward limit position. When the inner rod 11 moves forward to the forward limit position, the contact member 36 moves the sleeve 3
The flow path switching member 34 is set to the forward limit position by contacting the second stopper surface 32a.

The flow path switching tube 33 is located in a flow path switching space 35 formed on the outside of the flow path switching tube 33 and has an annular shape.
Two valve bodies 37, 38 are provided slidably, and a compression coil spring 41 for urging a spring force in a direction of separating these valve bodies 37, 38 from each other is attached. Has been done.

Two engaging grooves 4 are formed in one sleeve 31.
2 and 43 are formed, one engagement groove 42 is for backward limit positioning, and the other engagement groove 43 is for forward limit positioning. A ball 44 that engages with the engagement grooves 42 and 43 is provided in the end cover 15 so as to be movable in the radial direction, and a spring force toward the center is biased by the spring member (not shown) on the ball 44. As shown in FIG. 4, when the ball 44 is engaged with the engaging groove 42 for the backward limit positioning, the flow path switching member 34 is locked at the backward limit position, and the ball 44 is engaged for the forward limit positioning. Ditch 4
In the state of being engaged with 3, the flow path switching member 34 is locked at the forward limit position.

When the flow path switching member 34 reaches the retracted limit position as shown in FIG. 4, the valve element 37 separates from the valve seat 30a and the inner end surface of the sleeve 32 contacts the valve element 37. At this time, the valve body 38 comes into contact with the valve seat 15a and separates from the inner end surface of the sleeve 31. On the other hand, the flow path switching member 3
When 4 reaches the forward limit position, the valve element 37 contacts the valve seat 30a, and the inner end surface of the sleeve 32 is separated from the valve element 37. At this time, the valve body 38 separates from the valve seat 15a, and the inner end surface of the sleeve 31 contacts the valve body 38.

An air supply port 45 to which a compressed air source (not shown) is connected is formed on the rear end surface of the end cover 15.
An air supply flow path 46 is formed in the casing 14 so as to communicate with the air supply port 45, and the air supply flow path 46 is open to the flow path switching space 35 in which the valve bodies 37 and 38 are accommodated.

A supply / exhaust passage 47 is formed in the casing 14 so as to communicate with the retreat side pressure chamber 28a defined by the piston 27 of the outer rod 12, and the supply / exhaust passage 47 is formed as shown in FIG. In addition, when the flow path switching member 34 reaches the retracted limit position, the valve element 37 separates from the valve seat 30a and communicates with the flow path switching space 35.

A feed / exhaust passage 48 is formed in the casing 14 so as to communicate with the forward pressure chamber 28b defined by the piston 27 of the outer rod 12, and the feed / exhaust passage 48 is shown in FIG. When the flow path switching member 34 is at the retracted limit position, it communicates with the first exhaust hole 51 formed in the flow path switching tube 33, and the exhaust hole 51 is connected to the exhaust port of the end cover 15. It communicates with 50. Even if the contact member 36 comes into contact with the stopper surface 31a of the sleeve 31, the contact hole 36 and the exhaust port 5 are not connected.
A slit 36a for communicating with 0 is formed.

On the other hand, under the condition that the flow path switching member 34 is at the forward limit position, the flow path switching tube 33 is formed with the second exhaust hole 52 which communicates with the supply / exhaust flow path 47. . The air discharged from the exhaust holes 51 and 52 is exhausted to the outside from the exhaust port 50.

A bypass port 53 formed in the fixed cylindrical body 26 by opening on the outer peripheral surface of the outer rod 12 and a forward pressure chamber 25b defined by the piston 24 of the inner rod 11.
A bypass flow path 54 is formed in the casing 14 to communicate with the. As shown in FIG. 3, the bypass flow passage 54 communicates with the forward pressure chamber 25b at a gap 21a formed between the inner surface of the right end portion of the first tube 21 and the cylinder block 18, and 21a is a part of the bypass flow path 54.

3 and 4 show a state in which the inner rod 11 is at the backward limit position and the outer rod 12 is at the forward limit position.

Under this state, the compressed air from the air supply port 45 is supplied from the air supply / exhaust passage 47 into the backward pressure chamber 28a of the piston 27. As a result, the outer rod 12 moves backward. Outer rod 12
Moves backward to the reverse limit position, the reverse side pressure chamber 28
A bypass groove 55 is formed on the outer peripheral surface of the outer rod 12 in order to communicate the “a” with the bypass port 53. Therefore, when the outer rod 12 reaches the backward limit position, the air from the air supply port 45 enters the forward pressure chamber 25b via the air supply / exhaust passage 47, the backward pressure chamber 28a, the bypass groove 55, the bypass passage 54, and the gap 21a. Supplied.

At this time, in order to guide the air in the backward pressure chamber 25a to the forward pressure chamber 28b, the bypass passage 1 is provided between the inner rod 11 and the cylinder block 17.
7a (gap) is formed. Also, the outer rod 12
A bypass groove 56 is formed on the outer periphery of the rear end portion so as to connect the backward pressure chamber 25a and the forward pressure chamber 28b with each other via the bypass flow passage 17a. Therefore, when the outer rod 12 reaches the backward limit position, the inner rod 11 moves forward.

In this way, the backward pressure chamber 2 of the piston 27
8a and the forward pressure chamber 25b of the piston 24, and the bypass flow path 54 that bypasses and communicates with the forward pressure chamber 28b.
Bypass passage 17a for communicating the retreat side pressure chamber 25a
And two bypass channels are formed.

As shown in FIG. 3, the fixed cylindrical body 26 is formed with an annular groove 57a communicating with the retreat side pressure chamber 28a, and an annular groove having a V-shaped cross section is formed in the groove 57a. The seal member 57 is housed. The opening-side tip of the seal member 57 faces the retreat side pressure chamber 28a side, and allows a flow of air from the bypass port 53 toward the retreat side pressure chamber 28a, and functions as a check valve that blocks the flow in the reverse direction.

Therefore, when the outer rod 12 reaches the retracted limit position, the bypass port 53 passes through the bypass groove 55.
And the retreat side pressure chamber 28a are in communication with each other, and air is allowed to flow from the bypass port 53 toward the retreat side pressure chamber 28a even when the outer rod 12 is not in the retreat limit position.

As shown in FIG. 3, the head block 14a is formed with an annular groove 58a communicating with the forward pressure chamber 28b, and an annular seal having a V-shaped cross section is formed in the groove 58a. A member 58 is contained. The opening-side tip of the seal member 58 faces the forward pressure chamber 28b side, allows the flow of air from the backward pressure chamber 25a of the piston 24 toward the forward pressure chamber 28b via the bypass passage 17a, and is in the opposite direction. It functions as a check valve that blocks the flow.

Therefore, when the outer rod 12 reaches the forward limit position, the retreat side pressure chamber 25a and the forward side pressure chamber 28b communicate with each other through the bypass groove 56, and the outer rod 12 does not reach the forward limit position. However, the air flows from the backward pressure chamber 25a toward the forward pressure chamber 28b.

When the inner rod 11 moves to the forward limit position, the flow path switching member 34 reaches the forward limit position, the valve body 37 contacts the valve seat 30a, and the inner end surface of the sleeve 32 separates from the valve body 37. Since the supply / exhaust passage 47 is in communication with the exhaust hole 52, the valve body 38 is separated from the valve seat 15a, and the inner end surface of the sleeve 31 contacts the valve body 38, the supply / exhaust passage 48 is formed in the passage switching space 35. The communication with the air supply flow path 46 is established via the. As a result, the air from the air supply port 45 is supplied with the air supply passage 46, the passage switching space 35, and the supply / exhaust passage 48.
Through, the fluid flows into the forward pressure chamber 28b of the piston 27, and the outer rod 12 advances.

When the outer rod 12 moves to the forward limit position, the forward pressure chamber 28b and the backward pressure chamber 25a are brought into communication with each other through the bypass groove 56, and the air from the air supply port 45 enters the backward pressure chamber 25a. Will be supplied.
As a result, the inner rod 11 moves backward. When the inner rod 11 moves to the retreat limit position, the flow path switching member 34 reaches the retreat limit position as shown in FIG. 4, and the air supply port 45 and the air supply / exhaust flow path 48 are in communication with each other, and And the supply / exhaust flow path 47 are in communication with each other.

FIGS. 6A to 6C and 7D.
7 (f) is a diagram showing the connection state of the flow passages, respectively, and in these drawings, the flow passage between the air supply port 45 and the pressure chamber into which the compressed air is introduced is shown in black. The flow path between the pressure chamber and the exhaust port 50 through which the air from the pressure chamber is exhausted is shown with dots.

Table 1 shows the inner rod 11 and the outer rod 1.
2, the air supply port 45 and the exhaust holes 51, 5 according to the position of 2.
2 connection state and rod 1 in that state
The operation modes of 1 and 12 are shown.

[0044]

[Table 1]

First, as shown in FIG. 6 (a), when the inner rod 11 is at the backward limit position and the outer rod 12 is at the forward limit position, the air supply port 45 and the backward pressure chamber 28a of the piston 27 are supplied and exhausted. The communication is established via the flow path 47.
This communication state corresponds to FIG. 1A, in which the clamper 1 is at the backward limit position and is closed.

At this time, the forward pressure chamber 28b is in communication with the exhaust hole 51 through the supply / exhaust passage 48, and the air in the forward pressure chamber 28b is exhausted from the exhaust hole 51 to the exhaust port 50.
And is discharged from here. This causes the outer rod 12 to move backward. In the process of backward movement,
The compressed air that has flowed into the retreat side pressure chamber 28a does not flow into the bypass flow passage 54 due to the seal member 57 that functions as a check valve, and similarly, the air does not flow into the retreat side pressure chamber 25a due to the seal member 58.

FIG. 6B shows the outer rod 12 in the retracted limit position. In this state, the clamper 1 is opened as shown in FIG. In this state,
As shown in FIG. 6B, the supply / exhaust flow path 47 is provided with the bypass flow path 54 via the retract side pressure chamber 28 a and the bypass groove 55.
The air supply port 45 is connected to the piston 24.
Will communicate with the forward pressure chamber 25b. At this time, the communication between the bypass groove 56 and the forward pressure chamber 28b is released, but since the flow in this direction is allowed in the seal member 58 portion, the backward pressure chamber 25a includes the bypass passage 17a and the bypass groove. 56, the concave groove 58a and the forward pressure chamber 28b are brought into communication with the air supply / exhaust passage 48. As a result, the inner rod 11 moves forward.

FIG. 6 (c) shows a state in which the inner rod 11 is moving forward, and this forward movement causes the contact member 36 to separate from the stopper surface 31a of the sleeve 31.

FIG. 7D shows a state in which the inner rod 11 is at the forward limit position. In this state, as shown in FIG. 1C, the clamper 1 which has been opened is moved to the forward limit position. Equivalent to. In this state, as shown in FIG. 7 (d), the contact member 36 moves the stopper surface 32 a of the sleeve 32.
And the flow path switching member 34 is moved to the forward limit position. As a result, the ball 44 shown in FIG. 4 engages with the engagement groove 43 for positioning the forward limit, and the flow path switching member 34 is locked at this position. As a result, the flow path switching space 35 communicating with the air supply port 45 is in communication with the supply / exhaust flow path 48, and the supply / exhaust flow path 47 is in communication with the exhaust hole 52.

As a result, the compressed air supplied from the air supply port 45 flows into the forward pressure chamber 28b of the piston 27 via the air supply / exhaust passage 48, while the air in the backward pressure chamber 28a receives the air supply / exhaust passage 47. The exhaust gas is exhausted from the exhaust port 50 to the outside through the exhaust hole 52, and the outer rod 12 moves forward. At this time, the sealing member 57 blocks the flow from the backward pressure chamber 28a toward the bypass groove 55, and the sealing member 58 causes the forward pressure chamber 28 to flow.
The flow from b to the bypass groove 56 is blocked.

FIG. 7E shows the state where the outer rod 12 has moved to the forward limit position. In this state, the opening / closing member 2 has moved to the forward limit position as shown in FIG.
Corresponds to the closed state.

In this state, as shown in FIG. 7 (e), the bypass groove 56 and the forward pressure chamber 28b are in communication with each other, and the supply / exhaust passage 48 has the forward pressure chamber 28b, the bypass groove 56 and the bypass passage. 17a through the retreating side pressure chamber 25
The compressed air from the air supply port 45 communicates with a and flows into the retreat side pressure chamber 25a. On the other hand, in the seal member 57 portion, the air flowing from the bypass flow passage 54 toward the retreating side pressure chamber 28a flows, so that the advancing side pressure chamber 25b exhausts through the bypass flow passage 54, the bypass groove 55, and the supply / exhaust flow passage 47. It is in communication with the hole 52. As a result, the inner rod 11 moves backward.

FIG. 7F shows a state in which the inner rod 11 is moving backward. Inner rod 1 to the backward limit position
When 1 moves backward, the state shown in FIG. 6A is obtained, and the state shown in FIG. 6A to the state shown in FIG. 7F is further repeated. In this way, both the inner and outer rods 1 described above
The forward and backward movements of 1 and 12 are repeated continuously, that is, sequentially. As a result, the clamper 1 shown in FIG. 1 grabs an object, moves backward, opens the clamp, moves forward in the open state, and continues the operation of closing the clamper 1 as long as compressed air is supplied from the air supply port 45. The fish bones can be removed with the clamper 1, for example.

As described above, in the illustrated automatic reciprocating cylinder, the flow passage is automatically switched between the forward limit position and the backward limit position of the rod itself to be actuated.
It is possible to continuously reciprocate both rods 11 and 12 in a predetermined order without providing a solenoid valve. Moreover, the size of the pneumatic cylinder can be reduced.

Each of the bypass flow paths 54, 17a and 2
By changing the connection relationship between the pressure chambers on both sides of one piston 24, 27, the operating order of both rods can be changed.

In the illustrated embodiment, four tubes are attached to the outside of the piston 24 with a gap therebetween to form a part of the casing 14, but these parts are integrated. It may be formed by a general block member, and a passage through which air flows may be formed corresponding to each flow path.

FIGS. 8 to 11 are views showing a cylinder which is another embodiment of the present invention. FIG. 8 corresponds to the portion of FIG. 3 in the above embodiment and FIG. 9 shows the portion of FIG. Correspond. In these figures, the members common to the above-mentioned embodiment are designated by the same reference numerals.

In this embodiment, the head block 14a is provided with hose joints 61a and 62a corresponding to the air supply / exhaust passages 47 and 48 formed therein, which are shown in FIG. It is attached in a direction perpendicular to. Hose joints 61b and 62b are attached to the end block 14b corresponding to the hose joints 61a and 62a, and hoses 63 and 64 are connected to the corresponding hose joints.

The hose 63 which is connected to and constitutes a part of the air supply / exhaust passage 47 is communicated with the first port 65 formed in the end cover 15 as shown in FIG. The hose 64, which is connected to and constitutes a part of the exhaust passage 48, is in communication with the second port 66.

In order to detect the forward limit position and the backward limit position of the piston 24, sensors 67 and 68 are attached as shown in FIGS. 9 and 10, and as shown in FIG. 67 and 68 are relays 71 and 72
It is connected to the solenoid parts 74 and 75 of the solenoid valve 73 via. In FIG. 10, reference numerals 67a and 68a
Indicates a cord attachment portion for transmitting signals of the sensors 67 and 68, respectively.

In this case, the flow path switching member 34 shown in FIG. 4 is formed by the solenoid valve 73, and when the inner rod 11 reaches the forward limit position and the backward limit position, the electromagnetic switching is performed. By the operation of the valve 73, the compressed air is supplied to one of the two supply / exhaust passages 47, 48 and is exhausted via the other.

When the outer rod 12 reaches the forward limit position and the backward limit position, the flow paths are automatically switched via the bypass flow paths 17a and 54 as in the case shown in FIG. .

Although the invention made by the present inventor has been specifically described based on the embodiments, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the invention. Needless to say.

For example, the automatic reciprocating cylinder of the present invention is not limited to the case where the clamper is opened / closed and the clamper is moved back and forth, and when the two members are reciprocally moved in the axial direction in a predetermined procedure, It can also be used to operate such things. In this way, two members, one of which is operated by the inner rod 11 and the other of which is operated by the outer rod 1,
If the rods 11 and 12 are not in the forward limit position and the backward limit position when operating at 2,
Since the other rod does not operate, the cylinder can be operated safely and reliably without the need for an interlock mechanism.

Further, in the illustrated embodiment, each rod is operated by air pressure, but it may be operated by hydraulic pressure.

[0066]

Advantageous effects obtained by typical ones of the inventions disclosed in the present application will be briefly described.
It is as follows.

(1). Among the pistons provided on the two rods, the inner rod and the outer rod, respectively, when the piston of the outer rod reaches the forward limit position and the backward limit position, the outer rod itself switches the flow path. The inner rod can subsequently be activated continuously.

(2) When the inner rod reaches the forward limit position and the backward limit position, the supply of fluid to the piston of the outer rod switches, and the inner rod reaches the forward limit position or the backward limit position, and subsequently the outer rod continues to move. Can be activated.

(3) By providing the flow path switching member on the inner rod, it is not necessary to detect the forward limit position and the backward limit position of the inner rod by sensors or the like.

(4). The inner rod does not operate unless the outer rod reaches the forward limit position and the backward limit position, and the outer rod does not operate unless the inner rod reaches the forward limit position and the backward limit position. Since the rods are sequentially operated in a predetermined order, the inner and outer rods can be safely and reliably reciprocated.

[Brief description of the drawings]

FIG. 1 is a process diagram showing an operating state of forward / backward movement and opening / closing movement of a clamper.

FIG. 2 is a front view showing the outer appearance of a reciprocating cylinder that is an embodiment of the present invention.

3 is a cross-sectional view showing the internal structure of the front half of the reciprocating cylinder shown in FIG.

4 is a cross-sectional view showing the internal structure of the latter half of the reciprocating cylinder shown in FIG.

FIG. 5 is a right side view of FIG.

6 (a) to 6 (c) are schematic cross-sectional views showing communication states of flow paths according to the position of a rod.

7 (d) to (f) are schematic cross-sectional views showing communication states of the flow paths according to the position of the rod.

FIG. 8 is a cross-sectional view showing a front half portion of a reciprocating cylinder that is another embodiment of the present invention.

FIG. 9 is a cross-sectional view showing a second half portion of a reciprocating cylinder that is another embodiment of the present invention.

10 is a side view showing the right end face of FIG. 9. FIG.

11 is a circuit diagram showing a pneumatic circuit connected to the port shown in FIG.

[Explanation of symbols]

 11 Inner Rod 12 Outer Rod 13 Pneumatic Cylinder 14 Casing 14a Head Block 14b End Block 14c Cover Tube 15 End Cover 15a Valve Seat 16 Bolt 17,18 Cylinder Block 17a Bypass Flow Path (Gap) 21,22,23 Tube 24 Piston (No. 1) 1 piston) 25a backward side pressure chamber 25b forward side pressure chamber 26 fixed cylinder 27 piston (second piston) 28a backward side pressure chamber 28b forward side pressure chamber 30 annular support member 30a valve seat 31, 32 sleeve 33 flow path switching tube 34 flow path switching Member 35 Flow path switching space 36 Abutment member 37, 38 Valve body 41 Spring 42, 43 Engagement groove 44 Ball 45 Air supply port 46 Air supply flow path 47, 48 Air supply / exhaust flow path 50 Exhaust port 51, 52 Exhaust hole 53 Bypass Port 5 Bypass flow path 55, 56 bypass channel 61a, 61b, 62a, 62b hose joint 63 Hose 65 ports 67, 68 sensor 71, 72 relay 73 solenoid valve 74, 75 solenoid unit

Claims (2)

[Claims] 1. An inner rod having a first piston and a second rod.
A casing having a piston and an outer rod through which the inner rod penetrates is slidably provided in the axial direction, and a forward pressure chamber and a backward pressure chamber formed on both sides of the second piston are connected to the casing. Flow passage switching means connected to the two supply / exhaust passages for communicating these supply / exhaust passages with the supply port and the exhaust port, and a forward pressure chamber and a backward pressure chamber formed on both sides of the first piston. A first bypass passage communicating one of the two with one of the forward pressure chamber and the backward pressure chamber formed on both sides of the second piston, and the forward pressure chamber and the backward pressure chamber formed on both sides of the first piston. The other of the forward side pressure chamber and the second bypass flow passage formed on both sides of the second piston to communicate with the other of the forward side pressure chamber and the backward side pressure chamber, wherein the second piston is at either the forward limit position or the backward limit position. Become At this time, the fluid is supplied to one of the forward-side pressure chamber and the backward-side pressure chamber formed on both sides of the first piston through one of the forward-side pressure chamber and the backward-side pressure chamber formed on both sides of the second piston. An automatic reciprocating cylinder characterized in that the inner rod is actuated following the movement of the outer rod to the forward limit and backward limit positions. 2. The automatic reciprocating cylinder according to claim 1, wherein the flow passage switching means is attached to the inner rod, and one of the two supply / exhaust flow passages when the inner rod is at a forward limit position. And the air supply port are communicated with each other, and when the inner rod is in the retracted limit position, the other of the two supply / exhaust passages is communicated with the air supply port, and the inner rod is moved to the forward limit position and the retracted limit position. The automatic reciprocating cylinder, characterized in that the outer rod is actuated subsequently.