JP2576637Y2 - Air cylinder drive control circuit - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drive control circuit for an air cylinder.

[0002]

2. Description of the Related Art Generally, an air cylinder has a piston movably provided in a cylinder body thereof, and a supply / discharge port for supplying and exhausting air is formed in two chambers partitioned by the piston. The piston is moved by supplying and discharging air from the drive control circuit to the two supply and discharge ports.

Conventionally, in this type of air cylinder,
In some cases, a drive control circuit configured to move the piston at a high speed is connected to improve work efficiency. That is, in the initial state, the drive control circuit stops the piston at a predetermined position by supplying high-pressure air having the same pressure to the two chambers on both sides of the piston. And when moving a piston, while stopping supply of high pressure air to one chamber,
The piston is moved at high speed by exhausting the high-pressure air in the room from the supply / discharge port.

Further, if the moving speed of the piston is increased, it becomes difficult to stop the piston at a desired position. Therefore, the speed of the piston can be previously switched to a low speed before stopping the piston. . In this drive control circuit, two switching valves are connected in parallel, and the switching speed of the piston can be changed between a high speed and a low speed by switching all of the two switching valves.

[0005]

However, in the above-mentioned air cylinder drive control circuit, high pressure is applied in advance to the two chambers on both sides of the piston, and when the piston is operated, the piston is released while releasing the pressure in one chamber. , The start of movement of the piston was delayed by the amount required to release the high-pressure air.

That is, there is a large time lag from when the switching valve of the drive control circuit is switched to when the piston starts to move, which is a problem of speeding up the operation. The drive control circuit for switching the moving speed of the piston of the air cylinder between high speed and low speed is such that each switching valve is connected in parallel. Therefore, in the conventional structure, the air pipe becomes congested, and the number of signals for operating each switching valve increases, leading to an increase in cost. In addition, if one of the switching valves fails and does not operate, the cylinder cannot even be operated. Therefore, further improvement in reliability has been demanded.

The present invention has been made in view of the above circumstances, and a first object is to provide a drive control circuit for an air cylinder which can reduce a time lag until the piston starts moving. .

A second object of the present invention is to reduce the number of circuit pipes and the number of switching valves in addition to the first object, thereby reducing costs and improving reliability. An object of the present invention is to provide a drive control circuit for an air cylinder.

[0009]

In order to achieve the first object, in the first invention, a piston is movably provided in a cylinder body, and air is supplied to two chambers partitioned by the piston. Air supply and exhaust ports for air and exhaust are provided, and air at approximately the same pressure is supplied to the two chambers through these supply and exhaust ports.
To temporarily stop the piston and
An air cylinder configured to move the piston to the one chamber by exhausting the air.
The starting immediately before the cylinder for moving the piston to one chamber side, switching supply for a lower air pressure than the air pressure supplied to the other chamber in order to actuate the piston keep over the two chambers The gist is to have means.

In order to achieve the second object, in the second invention, the switching supply means includes a high-pressure air supply source for supplying a relatively high air pressure and an air pressure lower than the high-pressure air supply source. A supply air switching valve for switching between a low-pressure air supply source to be supplied, and a low-speed switching valve for reducing a moving speed of a piston between the supply air switching valve and the two supply / discharge ports; A high-speed switching valve for increasing the moving speed of the piston is connected in series, and a high-pressure or low-pressure air supply source and the two supply / discharge ports are provided when the low-speed switching valve and the high-speed switching valve are not operated. The gist of the present invention is that communication is established between

[0011]

According to the first aspect of the present invention, at least immediately before the start of the cylinder, the switching means applies an air pressure to both chambers smaller than the air pressure supplied to each chamber for operating the piston. The piston is stopped. In this state, when the low-pressure air in one chamber is extracted to operate the piston and high-pressure air higher than the low-pressure air is supplied to the other chamber, the difference in thrust applied to both sides of the piston immediately increases, The piston is actuated quickly.

According to the second invention, the low-speed switching valve and the high-speed switching valve are connected in series, respectively.
The circuit configuration can be simplified. When the piston is moved at low speed, the low-speed switching valve is switched,
When the piston is moved at a high speed, the high-speed switching valve can be switched, so that the number of switching of each switching valve can be reduced. Further, since the high-pressure or low-pressure air supply source and the two supply / discharge ports are connected to each other when the low-speed switching valve and the high-speed switching valve are not operated, one of the low-speed and high-speed switching valves is used. Even when the switching valve stops operating, the cylinder does not stop operating at all.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [First Embodiment] An embodiment of the present invention will be described below with reference to FIGS.

As shown in FIG. 1, a high-pressure air supply source 1 is connected to a supply air switching valve 3 via a high-pressure air supply line 2, and the air pressure in the high-pressure air supply line 2 is a pressure SP.
It is set to 1. The low-pressure air supply source 4 is connected to the supply air switching valve 3 via a low-pressure air supply line 5. A relief valve 6 is interposed in the low-pressure air supply line 5. The air pressure SP2 downstream of the relief valve 6 in the low-pressure air supply pipe 5 is set to a pressure lower than the pressure SP1 in the high-pressure air supply pipe 2 (SP1> SP2).

The supply air switching valve 3 is a two-position, three-port electromagnetic switching valve. When the electromagnetic solenoid 7 is in a demagnetized state, the supply air switching valve 3 can be switched to the home position b by the urging force of the spring 8. ing. When the electromagnetic solenoid 7 is excited, the position is switched to the position a.

At the position a, the supply air switching valve 3 connects the low-pressure air supply line 5 to the main line 9 and shuts off the high-pressure air supply line 2 from the main line 9. In the position b, the supply air switching valve 3 connects the high-pressure air supply line 2 to the main line 9 and shuts off the low-pressure air supply line 5 from the main line 9.

A low-speed switching valve 10 is connected to the main line 9 on the downstream side of the supply air switching valve 3. That is, the supply air switching valve 3 and the low speed switching valve 10 are connected in series.

The low-speed switching valve 10 is a three-position, five-port electromagnetic switching valve, and is switched to the a position when the first electromagnetic solenoid 11 is in the excited state and the second electromagnetic solenoid 12 is in the demagnetized state. It has become. When the first electromagnetic solenoid 11 is in the demagnetized state and the second electromagnetic solenoid 12 is in the excited state, the position is switched to the position c. Further, when the first and second electromagnetic solenoids 11 and 12 are in a demagnetized state, the urging forces of the two springs 13 are balanced to switch to the home position b.

In the low-speed switching valve 10, at the position a, the main line 9 and the second branch line 15 communicate with each other, and the first branch line 14 and the low-speed exhaust line 16 communicate with each other. It has become so. In the position b, the low-speed switching valve 10 is connected to the main line 9 and the first and second branch lines 14 and 1.
5 and the two branch pipes 14, 1
5 and the exhaust pipe 16 for low speed are cut off. Further, at the position c, the low-speed switching valve 10 is
And the first branch line 14, and the second branch line 15 and the low-speed exhaust line 16 are communicated.

A low-speed relief valve 17 is connected downstream of the low-speed exhaust pipe 16, and a low-speed needle valve 18 is connected in parallel with the low-speed relief valve 17. The low-speed relief valve 17 is set to the relief pressure RP1, and the low-speed needle valve 18 is set to the throttle amount NP1. A silencer 19 is connected downstream of the low-speed needle valve 18.

A high-speed switching valve 20 is connected to the first and second branch pipes 14 and 15 downstream of the low-speed switching valve 10. That is, the low-speed switching valve 10 and the high-speed switching valve 20 are connected in series.

The high-speed switching valve 20 is a three-position five-port electromagnetic switching valve, and is switched to the position a when the first electromagnetic solenoid 21 is in the excited state and the second electromagnetic solenoid 22 is in the demagnetized state. It has become. When the first electromagnetic solenoid 21 is in a demagnetized state and the second electromagnetic solenoid 22 is in an excited state, the position is switched to the position c. Further, when both the first and second electromagnetic solenoids 21 and 22 are in a demagnetized state, both springs 23
Are balanced and switched to the home position b.

At the position a, the high-speed switching valve 20 connects the first branch line 14 to the first supply / discharge line 24 and connects the second supply / discharge line 25 to the high-speed exhaust line 26. Are communicated, and the second branch line 15 is shut off. In the high-speed switching valve 20, at the position “b”, the first branch line 14 and the first supply / discharge line 24 communicate with each other, and the second branch line 15 and the second supply / discharge line 25 are connected. The high-speed exhaust pipe 26 is cut off. Further, at the position c, the high-speed switching valve 20 is connected to the second branch line 1.
5 and the second supply / discharge conduit 25, the first supply / discharge conduit 24 and the high-speed exhaust conduit 26, and the first branch conduit 14 is cut off. I have.

A high-speed relief valve 27 is connected downstream of the high-speed exhaust pipe 26, and a high-speed needle valve 28 is connected in parallel with the high-speed relief valve 27. The relief pressure RP2 of the high-speed relief valve 27 is set lower than the relief pressure RP1 of the low-speed relief valve 17 (RP1> RP2), and the throttle amount NP2 of the high-speed needle valve 28 is set to the low-speed needle valve 18
Is set to be smaller than the aperture amount NP1 (NP1>
NP2). A silencer 29 is connected downstream of the high-speed needle valve 28.

The first supply / discharge conduit 24 and the second supply / discharge conduit 2
5 is connected to a rodless cylinder (hereinafter simply referred to as a cylinder) 30 on the downstream side of the high-speed switching valve 20. That is, the piston 31 is housed in the cylinder 30 main body so as to be slidable in the longitudinal direction (the left-right direction in FIG. 1) while being in close contact with the inner peripheral wall of the cylinder 30.
Then, the inside of the cylinder 30 is firstly moved by the piston 31.
It is partitioned and formed into a chamber R1 and a second chamber R2.

At both ends of the cylinder 30 in the longitudinal direction,
A first supply / discharge port 32 communicating with the first chamber R1;
A second supply / discharge port 33 communicating with the chamber R2 is provided. The first supply / discharge conduit 24 is connected to the first supply / discharge port 32, and the second supply / discharge conduit 25 is connected to the second supply / discharge port 33.
, Respectively. Therefore, the low-speed switching valve 10 or the high-speed switching valve 20 is switched to switch between the two supply / discharge ports 3.
By selectively supplying air from the first and the second 32, the piston 31 is slid.

Although not shown, the cylinder 30 has:
A brake mechanism is provided for interfering with the piston 31 and forcibly stopping its sliding movement. next,
The operation of the above-configured cylinder and its control circuit will be described with reference to FIGS. FIG. 2 (a)
FIG. 5 is a graph showing changes in air pressures P1 and P2 applied to chambers R1 and R2 on both sides of the piston 31 and changes in a moving speed V of the piston 31. FIG. 2B is a time chart showing the operation of each of the electromagnetic solenoids 21, 12, and 7.

First, in the initial state, the electromagnetic solenoid 7 of the supply air switching valve 3 is excited, and the electromagnetic solenoids 11, 12, 21, 22 of the switching valve 10 for low speed and the switching valve 20 for high speed are all turned on. Demagnetized.
Therefore, the supply air switching valve 3 is held at the position a in advance, and the low speed switching valve 10 and the high speed switching valve 20 are held at the position b by the urging forces of the springs 13 and 23, respectively.

In this initial state, the low-pressure air SP2 from the low-pressure air supply source 4 receives the main line 9, the two branch lines 14, 15,
The air is supplied to the first chamber R1 and the second chamber R2 via the two supply / discharge conduits 24, 25 and the two supply / discharge ports 31, 32. for that reason,
The same low pressure SP2 is applied to each of the pressures P1 and P2 in the first chamber R1 and the second chamber R2. Therefore, the piston 31
, The same thrust is applied to both sides, and the thrust is completely canceled, and the piston 31 does not operate and stops at that position.

Here, the piston 31 is driven at a high speed from the stop state of the piston 31, and the piston 31 is moved in FIG.
After the predetermined time T1 elapses, the electromagnetic solenoid 7 of the supply air switching valve 3 is demagnetized, and the first electromagnetic solenoid 2 of the high-speed switching valve 20 is moved from the left side to the right side.
1 is excited. Further, the low-speed switching valve 10 is kept at the position b.

Then, the supply air switching valve 3 is switched to the position b, and the high pressure air supply pipe 2 and the main pipe 9 are communicated. Also, the high-speed switching valve 20 is switched to the position a, and the first
The branch pipe 14 and the first supply / discharge pipe 24 communicate with each other, and the second supply / discharge pipe 25 and the high-speed exhaust pipe 26 communicate with each other.

Therefore, in this state, the high-pressure air supply source 1
Is supplied to the first chamber R1 (P1 = SP1) and the pressure SP2 in the second chamber R2 is supplied.
Is quickly exhausted through the high-speed relief valve 27 and the high-speed needle valve 28 (P2 <SP2).

Therefore, as shown in FIG. 2 (a), a time lag t (=) from the time T1 when each of the switching valves 3 and 20 is switched to the time T2 when the piston 31 starts moving from the left side to the right side in FIG. T2-T1) becomes very short. Further, since the high-speed relief valve 27 and the high-speed needle valve 28 are connected in parallel, the moving speed of the piston 31, that is, the primary speed V1 is stabilized.

Then, the piston 31 is moved by a predetermined distance in FIG.
, The drive control circuit causes the piston 31 to shift from high-speed drive to low-speed drive. That is, after the lapse of the predetermined time T3, the first electromagnetic solenoid 21 that has been excited to that of the high-speed switching valve 20 is demagnetized, and the second electromagnetic solenoid 12 that has been demagnetized to that of the low-speed switching valve 10 is excited. . Further, the supply air switching valve 3 is kept at the position b.

Then, the low-speed switching valve 10 is switched to the position c, the main line 9 and the first branch line 14 are communicated, and the second branch line 15 and the low-speed exhaust line 16 are communicated. Is done. Further, when the high-speed switching valve 20 is switched to the home position b, the first branch line 14 and the first supply / discharge line 24 are communicated, and the second branch line 15 and the second supply / discharge line are connected. The communication with the pipe 25 is established.

Accordingly, in this state, the high-pressure air supply source 1
Is supplied to the first chamber R1 as it is, and the low-pressure air in the second chamber R2 is exhausted through the low-speed relief valve 17 and the low-speed needle valve 18. Here, the relief pressure RP of the low-speed relief valve 17
1 is set higher than the relief pressure RP2 of the high-speed relief valve 27 (RP1> RP2), and the throttle amount NP1 of the low-speed needle valve 18 is set larger than the throttle amount NP2 of the low-speed needle valve 28. (NP1> NP
2) Therefore, the exhaust of the low-pressure air from the second chamber R2 becomes gentle.

Therefore, as shown in FIG. 2A, the moving speed of the piston 31 is reduced, and the piston 31 is moved at the secondary speed V2. In this state, since the low-speed relief valve 17 and the low-speed needle valve 18 are connected in parallel, the moving speed of the piston 31, that is, the secondary speed V2 is stabilized.

When the piston 31 has reached the secondary speed V2, the piston 31 is stopped at a predetermined position by a brake mechanism (not shown). Since the brake is applied after the piston 31 is dropped from the primary speed V1 to the secondary speed V2, which is relatively slow, the piston 31 can be stopped at a desired position with high accuracy while increasing the moving speed of the piston 31.

On the other hand, when the piston 31 is stopped,
When moving from the right side to the left side, the low speed switching valve 1
The first electromagnetic solenoid 11 may be driven in place of the second electromagnetic solenoid 12 of 0, and the second electromagnetic solenoid 22 may be driven in place of the first electromagnetic solenoid 21 of the high-speed switching valve 20.

Therefore, in the first embodiment, the piston 31
Prior to the operation, the respective pressures P1 and P2 of the first chamber R1 and the second chamber R2 are maintained at the relatively small air pressure SP2. From this state, the high pressure SP1 is placed in the first chamber R1.
Is applied and the low pressure SP2 is discharged from the second chamber R2, so that the difference in thrust applied to both sides of the piston 31 increases immediately. Therefore, the time lag t until the operation of the piston 31 starts is extremely reduced. be able to.

The exhaust side of each supply / discharge port 32, 33 is
Needle valves 17, 27 and relief valves 18, 28, respectively
Are connected in parallel, the moving speed of the piston 31, that is, the primary speed V1 and the secondary speed V2 are stabilized.

Further, each of the switching valves 3, 10, and 20 is connected in series, and the switching between the primary speed V1 and the secondary speed V2 of the piston 31 is different from each other.
20 alone. Therefore, the number of wirings of the drive control circuit can be reduced as compared with the related art, and the switching valves 3 and 3 for switching the speed of the piston 31 can be reduced.
The number of switching operations of 10, 20 can be reduced, the switching control can be simplified, and the cost can be reduced and the reliability can be improved.

In addition, the home position (position b) when the low-speed switching valve 10 and the high-speed switching valve 20 are not operated.
In this configuration, the high-pressure or low-pressure air supply sources 1 and 4 are configured to directly communicate with the downstream side. Therefore, even if one of the switching valves 10 and 20 for low-speed or high-speed operation fails and stops operating, it is possible to prevent a situation in which the operation of the cylinder 30 cannot be completely performed, and further reliability is improved. Can be improved. Second Embodiment Next, a second embodiment of the invention will be described with reference to FIG. The same components as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

As shown in FIG. 3, the low-speed exhaust pipe 16 is divided into two branches, one of which is the first low-speed exhaust pipe 1.
Downstream of the first low-speed relief valve 40 and the first
A low-speed needle valve 41 is connected in parallel. A second low-speed relief valve 42 and a second low-speed needle valve 43 are connected in parallel downstream of the second second low-speed exhaust pipe 16b.

The longitudinal direction of the main body of the cylinder 30 is vertical, and a piston rod 44 projects from the lower surface of the piston 31. The work W fixed to the projecting end of the piston rod 44 is transported based on the movement of the piston 31.

In the drive control circuit configured as described above, each of the switching valves 3 and 1 when the piston 31 is moved.
The operation order of 0 and 20 is exactly the same. Therefore, according to the second embodiment, the relief pressures of the two relief valves 40 and 42 can be set to be different from each other, and the throttle amounts of the two needle valves 41 and 43 can be set to be different from each other. . Therefore, when moving the piston 31 at a low speed, the downward moving speed and the upward moving speed of the piston 31 can be made variable.

The present invention is not limited to the above two embodiments. For example, instead of connecting the relief valve 17 and the like and the needle valve 18 and the like in parallel on the exhaust side, the relief valve or the needle valve may be used. Only one of them may be connected to reduce the cost. Also, the order of connecting the low-speed switching valve 10 and the high-speed switching valve 20 is changed so that the high-speed switching valve 20
May be connected in series with the low-speed switching valve 10 downstream of.

[0048]

[Effects of the Invention] As described in detail above, according to the first invention, two chambers separated by a piston in a cylinder body are provided.
Supply air at approximately the same pressure to temporarily stop the piston
Together with exhausting air from one chamber
The piston is moved to one chamber side.
High-pressure air to move the
However , there is an excellent effect that the time lag until the piston starts moving can be reduced.

According to the second invention, in addition to the above effects,
It is possible to reduce the number of pipes in the circuit and the number of switching of the switching valve, thereby achieving an excellent effect of reducing cost and improving reliability.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing a first embodiment of the present invention and illustrating a drive control circuit of an air cylinder.

FIG. 2A shows chambers R1, R2 on both sides of a piston 31;
Of the air pressures P1 and P2 applied to the
FIG. 5 is a graph showing a change in a moving speed V of the moving object. (B)
5 is a time chart illustrating the operation of each of the electromagnetic solenoids 21, 12, and 7.

FIG. 3 is a circuit diagram showing a first embodiment of the present invention and illustrating a drive control circuit of the air cylinder;

[Explanation of symbols]

1, 3, 4 ... High-pressure air supply source, supply air switching valve and low-pressure air supply source constituting switching means, 10 ... Low-speed switching valve,
20: High-speed switching valve, 30: Rodless air cylinder as cylinder, 31: Piston, 32, 33: First supply / discharge port, second supply / discharge port as supply / discharge port, R1,
R2: first and second chambers as chambers, SP1, SP2 ... air pressure

Claims (2)

(57) [Scope of request for utility model registration] A piston (3) is provided in a cylinder (30) body.
1) is provided movably, and supply / discharge ports (32, 33) for supplying and exhausting air are provided in the two chambers (R1, R2) partitioned by the piston (31), respectively. , 33) to the two chambers (R1, R2)
Supply air at approximately the same pressure to temporarily stop the piston (31).
While stopping the air in one chamber (R1 or R2).
By evacuating, the piston (31) is moved into one chamber (R1).
Or R2) , at least the piston (31) is moved to one chamber (R2).
Immediately before starting the cylinder (30) to be moved to the 1 or R2) side , the other (
Switching supply means (1, 3) for applying an air pressure (SP2) lower than the air pressure (SP1) supplied to the chamber (R2 or R1) to the two chambers (R1, R2). , 4), an air cylinder drive control circuit. 2. The switching supply means (1, 3, 4) includes a high-pressure air supply source (1) for supplying a relatively high air pressure (SP1) and an air pressure (S) lower than the air pressure (SP1).
A supply air switching valve (3) for switching between a low pressure air supply source (4) for supplying P2) and a supply air switching valve (3) between the supply air switching valve (3) and the supply / discharge ports (32, 33). Is
A low-speed switching valve (10) for reducing the moving speed of the piston (31) and a high-speed switching valve (20) for increasing the moving speed of the piston (31) are connected in series. Low-speed switching valve (10) and high-speed switching valve (2
In the non-operation position (b, b) of 0), the high-pressure or low-pressure air supply source (1, 4) and the two supply / discharge ports (32, 33) are provided.
The drive control circuit for an air cylinder according to claim 1, wherein the control circuit is configured to communicate with the air cylinder.