JP2544693Y2 - Safety control device - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION The present invention is used for an air device for operating an operating member or the like of various machines by an air actuator. When the pressure on the exhaust side of the air actuator is lower than a predetermined pressure (for example, atmospheric pressure). The present invention relates to a safety control device for preventing runaway runaway.

[0002]

2. Description of the Related Art After the air supply has been stopped for a long time or after the residual pressure has been removed, the pressure on the exhaust side is lower than a predetermined pressure (for example, atmospheric pressure). Then, the piston or the like may jump out and run away. Conventionally, as a countermeasure, a pressure center type three-position valve is used as a main switching valve (main valve) to start the air actuator once after supplying air, or to perform meter-in control.
(For the conventional pop-out prevention technology, see "New Edition Hydraulic and Pneumatic Handbook" No. 439-
(See page 440)

In the conventional pop-out prevention technology, a pressure center type three-position valve can be used as a main switching valve only in special cases, and when meter-in control is used to prevent pop-out, other controls are limited. This makes it difficult to achieve the desired operation. As described above, the conventional pop-out prevention technology has a drawback that its application range is extremely limited and its utility value is low.

[0004]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned drawbacks of the prior art, and provides a safety switch to various main switching valves.
It is an object of the present invention to provide a pop-out preventing function by combining a magnetic valve so that the magnetic valve can be applied to all types of air equipment using an air actuator.

[0005]

[Means for Solving the Problems] Safety of the present inventionControl device
In order to achieve the above task,Inflow port of main switching valve
The A port of the safety solenoid valve is connected to
A central position where all ports A, P and R are closed;
A port communicates with R portAnd the P port is closedreturn
Position and P port communicate with A portR port is closed
BeWith feed positionI, P port is narrowed down to A port
Communicate in stateR port is closedProtruding position
It is configured to be provided.In interpreting the present invention,
In doing so, the following items must be considered: The A port is an air actuator (for example, an air
, Air motor. ) Through the main switching valvehandPo through
P port and R port are air source and atmosphere respectively.
This is a port that communicates with the inside. In the present invention, the term air (compressed air)
All gases with the specified pressure (including air and nitrogen gas)
No. ) Means the air source to be supplied to the switching valve and the safety solenoid valve
The same or different air source
Good. In the present invention, the operation method of the safety solenoid valve is
Type, electromagnetic air pilot type as well as mechanical type and manual type
And any other operating means. In the present invention, the operating position of the safety solenoid valve is
Take any position between the position and the pop-out prevention position
Can be. To get this intermediate position,
A piston can be placed to limit the movement of tons
You. Of the present inventionThe main switching valve has an exhaust center type,
Rosed center type, pressure center type and other arbitrary types
The type applies.

[0006]

[Action] The A port of the safety solenoid valve communicates with the main switching valve ,
Connect the actuator to the main switching valve, and connect the P port and R port to the air source and the atmosphere, respectively. When the safety solenoid valve is at the center position, the air actuator stops, air is supplied to the air actuator when the safety solenoid valve / main switching valve is at the feed position, and air is supplied from the air actuator when it is at the return position. Will be leaked. When it is desired to send air to the air actuator to operate the air actuator in a state where the remaining air in the air actuator is removed, the safety solenoid valve is switched to the pop-out prevention position.
Then, the air is gradually supplied to the air actuator via the throttle to prevent the air actuator from jumping out.

[0007]

1 and 2 show a safety control according to a first embodiment of the present invention.
FIG. 1 is a circuit diagram using the device , and FIG. 1 shows a safety solenoid valve 2 in a cross-sectional view, and FIG. 2 shows the safety solenoid valve 2 with symbols indicating functions. The body 4 of the safety solenoid valve 2 (which is obtained by connecting a plurality of blocks) is axially forward (see FIG. 1).
From the left), the first pilot chamber 5, the centering chamber 6, the spool chamber 7, the second pilot chamber 8, and the stopper chamber 9 in that order.
And a stepped hole 10 are formed. A first hole 11 is formed in a wall between the first pilot chamber 5 and the centering chamber 6, and a second hole 11 is formed in the wall.
A second hole 12 is formed in a wall between the pilot chamber 8 and the stopper chamber 9.
Is formed. A first pilot piston 13 and a second pilot piston 14 having a projection are slidably fitted in the first pilot chamber 5 and the second pilot chamber 8, respectively, and the projection of the first pilot piston 13 is rearward (in FIG. 1). The second pilot piston 14 is fixed to the front surface. A spool 15 is fitted in the spool chamber 7 in a slidable and as tightly sealed state as possible, and a first land is provided at a front end (left end in FIG. 1) and a first land is provided at a rear end (right end in FIG. 1). Two lands are formed, the connecting rod 16 is fixed to the front end of the spool 15, and the contact portion 17 is fixed to the front end of the connecting rod 16. Two spring receivers 22 and 23 are disposed in the centering chamber 6, and an insertion hole is formed in the center of each spring receiver 22 and 23. The connecting rod 16 is inserted through the insertion hole, and The centering spring 18 is interposed between the spring receivers 22 and 23. When all of the double solenoid pilot valves 21 fixed to the front of the body 4 are not energized, the two spring receivers 22 and 23 are pressed against the front end and the rear end of the centering chamber 6 by the resilience of the centering spring 18. The position of the contact portion 17 and the first land is defined by the
Is held in the center position. When the spool 15 is at the center position, the first land is located at the front end of the spool chamber 7 and
The land is located at the rear end of the spool chamber 7, and the contact portion 17 is the first
It is located inside the hole 11. An A port is opened on one side surface (the upper side surface in FIG. 1) of the body 4, and the A port communicates with a central portion of the spool chamber 7 through a passage 24. An R port, a P port, and a C port are sequentially opened on the other side surface (the lower side surface in FIG. 1) of the body 4 from the front, and the R port communicates with a front portion of the spool chamber 7 through a passage 26. The port C is communicated with the rear part of the spool chamber 7 through the passage 25, and the C port is communicated with the rear end face of the stopper chamber 9 through the passage 27. The inner diameter of the stopper chamber 9 is equal to or larger than the inner diameters of the first pilot chamber 5 and the second pilot chamber 8, and the throttle stopper piston 30 is slidably fitted in the stopper chamber 9.
A cylindrical stopper 31 is integrally fixed to the front surface of the throttle stopper piston 30. The cylindrical stopper 31 is slidably inserted into the second hole 12, and a central portion of the throttle stopper piston 30 has an inner diameter of the cylindrical stopper 31. A sliding hole with a smaller diameter than that is formed. An adjustment screw 32 is screwed into the stepped hole 10, and the adjustment screw 32
Is slidably inserted through the sliding hole of the throttle stopper piston 30, and a flange 34 is fixed to the front end of the rod portion 33. The flange 34 is always located inside the cylindrical stopper 31. When the adjusting screw 32 is rotated, the adjusting screw 32 moves forward and backward, and the position of the flange 34 can be changed. By tightening the locking stopper 35, the position can be maintained. The rearward movement of the spool 15 and the second pilot piston 14 is limited by moving the throttle stopper piston 30 and the cylindrical stopper 31 forward. The A port is connected to the main switching valve 19 (s) by piping, the P port is connected to the pneumatic source 3 by piping, and the C port is connected to the pneumatic source 3 via the switching valve 36. The main switching valve 19 is a pressure center type switching valve as shown, and is connected to control the double-acting air cylinder 1. It is also possible to connect a single-acting air cylinder to the A port without passing through the main switching valve.

The operation of the safety solenoid valve 2 used in the safety control device according to the first embodiment of the present invention shown in FIGS. 1 and 2 will be described. When all the solenoids of the double solenoid pilot valve 21 and the solenoid of the switching valve 36 are not energized, no air is supplied to the first pilot chamber 5, the second pilot chamber 8 and the stopper chamber 9, so that the spool 15 Maintained in position, A port, P port, R port are all closed. At this time, the cylindrical stopper 31 is at the rear end position, and the front end of the cylindrical stopper 31 does not enter the second pilot chamber 8. When the solenoid of the switching valve 36 is energized, it is switched to the position I, and air flows from the pneumatic source 3 into the stopper chamber 9 through the switching valve 36, the C port, and the passage 27, and moves the throttle stopper piston 30 forward. Let it. The throttle stopper piston 30 moves forward until it comes into contact with the flange 34 (the amount of movement is changed by the adjustment screw 32), and the cylindrical stopper 31 enters the second pilot chamber 8 by a predetermined amount. Next, when one solenoid of the double solenoid pilot valve 21 is energized, air is supplied to the front chamber of the first pilot chamber 5 through the passage 29, and the first pilot piston 13 is moved rearward (to the right in FIG. 1). Moving. However, when the second pilot piston 14 comes into contact with the front end of the cylindrical stopper 31, the movement of the first pilot piston 13 is stopped.
The reason for the stop is that the force of the first pilot piston 13 to move the spool 15 backward (the elastic force of the centering spring 18 and the force of the throttle stopper piston 30) This is because the combined force of the two is greater. Therefore, the spool 15 stops at the pop-out prevention position moved backward by a predetermined distance from the center position. At this time, the air from the pneumatic source 3 is supplied to the P port and the passage.
25, the flow rate is adjusted at the second land of the spool 15,
The air gradually flows into both sides of the air cylinder 1 through the central position II of the main switching valve 19 through the passage 24 and the A port. In this way, the protrusion of the air cylinder 1 is prevented. next,
When the solenoid of the switching valve 36 is de-energized, the stopper chamber 9
Is discharged into the atmosphere through the passage 27, the C port, and the switching valve 36, and no air acts on the throttle stopper piston 30. In this way, the restriction on the backward movement of the spool 15 is released, and the spool 15 is switched to the feed position at the rear end. The air is supplied from the P port to the main switching valve 19 through the A port without adjusting the flow rate by the spool 15, and the air cylinder 1 is operated by switching the main switching valve 19 to the position I or the position III . be able to. When the other solenoid of the double solenoid pilot valve 21 is energized, air is supplied to the rear chamber of the second pilot chamber 8 through the passage 28, and the second pilot piston 14 moves forward (to the left in FIG. 1). Then, the spool 15 is switched to the return position. The A port is connected to the atmosphere via the passage 24, the passage of the spool 15, the passage 26, and the R port.

[0009] Figure 3 is a circuit diagram using the safety control device <br/> the second embodiment of the present invention, the safety control device of the safety solenoid valve 39
Is shown in a sectional view. FIG. 3 is functionally equivalent to FIG. 2, and FIG. 2 is a safety control device according to the second embodiment.
A circuit diagram using a safety solenoid valve 39 of the location, the safety solenoid valve
It can be said that 39 is indicated by a symbol representing a function. In the second embodiment, the positions of the P port and the R port are opposite to those of the first embodiment, and the length of the cylindrical push member 41 of the throttle push piston 40 and the length of the rod portion 43 of the adjustment screw 42 are reduced. Are longer than the lengths of the cylindrical stopper 31 and the rod portion 33 of the first embodiment.
That is, when the throttle push piston 40 is moved forward (to the left in FIG. 3) when the spool 15 is at the center position, the distal end of the cylindrical push member 41 comes into contact with the rear end surface of the second pilot piston 14, and By moving, the spool 15 can be moved forward by a predetermined distance from the center position. However, since the remaining configuration of the second embodiment is the same as that of the first embodiment, the same reference numerals are used for the same portions, and the description of the configuration of the same portion is omitted.

The safety of the second embodiment of the present invention shown in FIG.
The operation of the safety electromagnetic valve 39 used in the control device will be described. When all the solenoids of the double solenoid pilot valve 21 and the solenoid of the switching valve 36 are not energized, no air is supplied to the first pilot chamber 5, the second pilot chamber 8 and the stopper chamber 9, so that the spool 15 Maintained in position, A port, P port, R port are all closed. At this time, the cylindrical stopper 41 is at the rear end position, and the front end of the cylindrical stopper 41 does not enter the second pilot chamber 8. Next, when the solenoid of the switching valve 36 is energized, it is switched to the position I, and the air flows from the pneumatic source 3 into the stopper chamber 9 through the switching valve 36, the C port, and the passage 27, and moves the throttle push piston 40 forward. Move to The throttle push piston 40 moves forward until it comes into contact with the flange 44 (the amount of movement is changed by the adjusting screw 42), and the cylindrical push member 41 enters the second pilot chamber 8 by a predetermined amount. At this time, the front end of the cylindrical push member 41 is
The spool 15 comes into contact with the pilot piston 14 and moves forward by a predetermined distance against the elastic force of the centering spring 18, so that the position of the spool 15 becomes the position. Therefore, the air from the air pressure source 3 passes through the P port and the passage 26,
The flow rate is adjusted by the land, and the air gradually flows into both sides of the air cylinder 1 through the central position II of the main switching valve 19 through the passage 24 and the A port. In this way, the protrusion of the air cylinder 1 is prevented. Next, when the solenoid of the switching valve 36 is de-energized and the other solenoid of the double solenoid pilot 21 is energized at the same time, air is supplied to the rear chamber of the second pilot chamber 8 and the second pilot piston 14 is moved to the front end (FIG. 1 to the left end), and the spool 15 is switched to the feed position. The air is supplied from the P port to the main switching valve 19 through the A port without adjusting the flow rate by the spool 15, and the air cylinder 1 is operated by switching the main switching valve 19 to the position I or the position III . be able to. When one solenoid of the double solenoid pilot valve 21 is energized, air is supplied to the front chamber of the first pilot chamber 5, the first pilot piston 13 moves to the rear end (the right end in FIG. 1), and the spool 15 moves. Switch to return position. The A port is communicated with the atmosphere via the passage 24, the passage of the spool 15, the passage 25, and the R port.

[0011]

The A port of the safety solenoid valve is connected to the main switching valve, an air actuator is connected to the main switching valve , and the P port and the R port are connected to the air source and the atmosphere, respectively. When it is desired to send air to the air actuator and operate it when the residual air in the air actuator is removed, the safety solenoid valve is switched to the pop-out prevention position, and the air is gradually supplied to the air actuator via the throttle, The protrusion of the air actuator is prevented.
The safety control device of the present invention can be applied to any pneumatic device using an air actuator. In addition, existing
The safety solenoid valve of the present invention is interposed between the main switching valve and the air source.
To prevent the air actuator from popping out.
It can be improved to a safety control device with functions.

[Brief description of the drawings]

FIG. 1 is a circuit diagram using a safety control device according to a first embodiment of the present invention, in which a safety solenoid valve of the safety control device is illustrated in a longitudinal sectional view.

FIG. 2 is a circuit diagram using the safety solenoid valve of the first or second embodiment of the safety control device of the present invention, wherein the safety solenoid valve is indicated by a symbol.

FIG. 3 is a circuit diagram using a safety control device according to a second embodiment of the present invention, in which a safety solenoid valve of the safety control device is illustrated in a longitudinal sectional view.

[Explanation of symbols]

 2 Safety solenoid valve 19 Main switching valve 39 Safety solenoid valve Protrusion prevention position Feed position Center position Return position

Claims (1)

(57) [Scope of request for utility model registration] A safety solenoid valve is connected to an inlet port of a main switching valve.
Port is communicated, safety solenoid valve, A, P, and the center position that all of the ports are closed in R, and a return point A port P port in communication with the R port is closed, P port A port Yes a feed position in which communication to R port is closed
And, R port communicated in a state where the P port is narrowed down to the A port
Safety control device with a pop-out prevention position where the door is closed
Place.