JPH059576Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a vacuum pressure control valve used when vacuum pressure is used to attract and release objects.

[Prior Art] Conventionally, as shown in FIG. 4, two electromagnetic valves 1 and 2 are used as vacuum pressure control valves when vacuum pressure is used to attract and release objects. The electromagnetic valves 1 and 2 are two-port valves having a port that communicates with a suction pad 3 and a port that communicates with a vacuum source 4 such as a vacuum pump or a pressurized air source 5 such as a compressor or air receiver. .

In such a vacuum pressure control valve, when the solenoid a of the electromagnetic valve 1 is energized in the illustrated inactive state, the suction pad 3 communicates with the vacuum source 4, so that the desired article can be suctioned and held by the vacuum pressure. can. Further, when the solenoid a is de-energized and the solenoid b of the solenoid valve 2 is energized, the suction pad 3 is communicated with the pressure air source 5, so that the vacuum pressure of the suction pad 3 is eliminated by the pressurized air. The adsorbed items are released.

However, in the conventional vacuum pressure control valve described above, when the vacuum pressure is applied to the suction pad 3 to attract and hold the article, if the solenoid a of the solenoid valve 1 is demagnetized due to a power outage, etc., the suction pad 3 and the vacuum source 4 are cut off, the suction pad 3 loses its ability to suction and hold the article, potentially causing a serious accident.

In order to eliminate the above-mentioned drawbacks of the vacuum pressure control valve, as shown in FIG. A vacuum pressure control valve may be considered in which the pilot valve 12 is provided with a detent mechanism 15 for holding the switching position and a solenoid c for releasing the lock of the detent mechanism 15.

In this vacuum pressure control valve, pilot valve 1
Each of the solenoids a, b, and c in the valves 1 and 12 is de-energized, and the pilot chambers at both ends of the directional control valve 14 are opened to the atmosphere through the pilot valves 11 and 12.
As a result, when the switching valve 14 is in the neutral position shown in the figure, the ports communicating with the suction pad 3, the vacuum source 4, and the pressure air source 5 are all closed, so the operation of the suction pad 3 is stopped. ing.

When solenoid b is energized in this state, pilot fluid from the pressure air source 5 flows into the pilot valve 12.
Since the suction pad 3 is supplied to the pilot chamber on the left side of the switching valve 14 through the switching valve 14, the suction pad 3 is communicated with the vacuum source 4 by switching the switching valve 14.

In this switching state, the pilot valve 12 is held in this state by the detent mechanism 15.
Even if the solenoid b is demagnetized due to a power outage or the like while the suction pad 3 is suctioning and holding an article, the suction pad 3 will not lose its ability to suction and hold the article.

Next, when the solenoid c is energized, the position holding by the detent mechanism 15 is released and the pilot valve 12 returns to the state shown in the figure, and the pilot fluid in the pilot chamber on the left side of the switching valve 14 is discharged to the atmosphere, so that the switching The valve 14 is returned to the illustrated neutral position by the biasing force of the spring.

Thereafter, when the solenoid a of the pilot valve 11 is energized, pilot fluid is supplied to the pilot chamber on the right side of the switching valve 14.
moves to the left and the suction pad 3 is communicated with the pressurized air source 5, so that the article suctioned and held by the suction pad 3 is released. Next, when the solenoid a is de-energized, the pilot fluid in the pilot chamber on the right side of the switching valve 14 is discharged to the atmosphere through the pilot valve 11, so the switching valve 14 is moved to the neutral position shown in the figure by the biasing force of the spring. The suction pad returns to its resting state.

In the vacuum pressure control valve, the detent mechanism 15 maintains the pilot air supply position of the pilot valve 12 when the directional switching valve 14 switches the communication between the suction pad 3 and the vacuum source 4. Defects can be eliminated.

However, in general, the operation of a suction pad that suctions and releases an article does not require a resting state between suctioning and holding the article and releasing it, although it requires a resting state between releasing the article and suctioning and holding the article. The vacuum pressure control valve described above has the disadvantage that it is wasteful in operation and is expensive since it requires a separate solenoid c for the pilot valve 12.

[Problems to be solved by the invention] This invention prevents the suction pad from losing its suction and holding function even if the solenoid is demagnetized due to a power outage, etc., and also allows the suction pad to remain in a dormant state between suction and holding and release. The problem to be solved is to obtain an inexpensive vacuum pressure control valve that eliminates the operational waste caused by the intervention of the vacuum pressure control valve.

[Means for solving the problems] The present invention is a vacuum pressure control valve that includes a main valve and an electromagnetically driven pilot valve that drives the main valve.
The main valve has a switching position for communicating or closing the output port communicating with the suction pad with a vacuum pressure port communicating with the vacuum source, and a switching position for communicating or closing the output port communicating with the pressure air source. A vacuum pressure valve section and a supply valve section each having a switching position, and a drive section that opens and closes these valve sections are provided,
The body of the pilot valve is provided with a flow path for supplying pilot fluid for opening the vacuum pressure valve portion to the driving portion of the main valve when the valve member is in the first switching position due to the excitation of one solenoid; The second valve member is activated by energizing the other solenoid.
At the switching position, the driving section of the main valve is provided with a flow path for supplying pilot fluid to close the vacuum pressure valve section and open the supply valve section at the same time, and even if one solenoid is demagnetized, the valve member remains in the above position. The above-mentioned problem is solved by providing a detent mechanism section that holds the switch at the first switching position.

[Operation] When both solenoids are de-energized,
The suction pad is at rest because the valve member is in a neutral position and the main valve is in a neutral position closing the supply valve section and the vacuum pressure valve section.

When one solenoid is energized in this state, the valve member switches to the first switching position, thereby supplying pilot fluid to the drive section of the main valve, which then opens the vacuum pressure valve section and transfers the output port to the output port. is communicated with the vacuum pressure port, so vacuum pressure acts on the suction pad. In addition, since the detent mechanism holds the valve member in its switching position, even if the solenoid is demagnetized when the pilot valve is in the first switching position, the pressure relationship in the drive unit does not change, and the output of the main valve remains unchanged. Communication between the port and the vacuum pressure port is never interrupted.

Next, when the power to the solenoid is cut off and the other solenoid is energized, the suction force of the solenoid releases the position of the valve member by the detent mechanism, and this suction force causes the valve member to release the return spring. It switches to the second switching position against the biasing force. This reverses the pressure relationship in the drive section, so that the main valve closes the vacuum valve section and opens the supply valve section. Therefore, pressurized air from the pressurized air source is supplied to the suction pad. In this case, the valve member of the pilot valve does not temporarily stop at the neutral position, and the main valve also does not assume the neutral position, that is, the rest state.

Furthermore, when the excitation of both solenoids is released, the valve member returns to the neutral position due to the biasing force of the return spring, and the main valve therefore returns to the neutral position and closes the supply valve section.

[Embodiment] FIGS. 1 and 2 show an embodiment of the present invention, and this vacuum pressure control valve includes a main valve 20, a pilot valve 50 that drives the main valve 20, and a pilot valve 50 that drives the main valve 20.
The first and second solenoids 5 switch the switching position of
1,52.

The valve body 21 of the main valve 20 has a supply port 22 communicating with the pressure air source 5, an output port 23 communicating with the suction pad 3, and a vacuum pressure port 24 communicating with the vacuum source 4. Part 2
5. A vacuum pressure valve section 26 and a drive section 27 are provided.

The supply valve section 25 includes a supply valve seat 29 that communicates the supply port 22 and the output port 23, and a cylindrical back chamber having approximately the same diameter as the supply valve seat 29 is formed at a position opposite to the supply valve seat 29. A supply valve body 30 for opening and closing the supply valve seat 29 is slidably inserted into the supply valve seat 29, and a main valve spring 31 for pressing the supply valve body 30 against the supply valve seat 29 is compressed. In addition, the above-mentioned back chamber is
A communication hole provided therein communicates with the output port 23 side.

A vacuum pressure valve section 26 formed coaxially with the supply valve section 25 has an output port 23 and a vacuum pressure port 24.
The supply valve seat 32 is provided with a vacuum pressure valve seat 32 that communicates with the supply valve seat 29, and the vacuum pressure valve seat 32 is formed to face the supply valve seat 29 and the supply valve seat 29. Further, a cylindrical back chamber is formed at a position facing the vacuum pressure valve seat 32 in the valve body 21, and a vacuum pressure valve body 33 for opening and closing the vacuum pressure valve seat 32 is slidably inserted into the back chamber. , a main valve spring 34 that presses the vacuum pressure valve body 33 against the vacuum pressure valve seat 32 is compressed. In addition, the above-mentioned back chamber is
A communication hole provided therein communicates with the output port 23 side.

A drive unit 27 that drives the supply valve unit 25 and the vacuum pressure valve unit 26 includes a supply valve body 30 and a vacuum pressure valve body 3.
Rod 3 is slidably inserted into the rod insertion hole of 3.
5, and a large diameter portion is formed in the portion of the rod 35 between the supply valve body 30 and the vacuum pressure valve body 33. In the neutral state shown in FIG.
5 and the vacuum pressure valve section 26 are both in the closed state and the rod 35 is in the downward movement state,
The vacuum pressure valve body 33 maintains the closed state while allowing the rod 35 to move downward, and the supply valve body 30 is opened by the downward movement against the biasing force of the main valve spring 31 by the lower surface of the large diameter portion. Furthermore, when the rod 35 is in the upward movement position, the supply valve section 25 is closed and the vacuum pressure valve section 26 is opened, contrary to the above.

The piston 38 to which the rod 35 is fixed defines a first pilot chamber 39 and a second pilot chamber 40 in the valve body 21, and is driven in the axial direction by the pressure difference between them. and the second pilot chamber 40 communicate with a first pilot passage 41 and a second pilot passage 42, respectively. Therefore, the piston 38 and the rod 35 move downward when the pressure in the second pilot chamber 40 is greater than that in the first pilot chamber 39;
It moves upward when it is small.

On the other hand, the body 54 of the pilot valve 50 shown in detail in FIG. Containment room 56
are formed, and a detent mechanism section 57 is provided at the other end. In addition, the body 54 has
A pressure port 59 communicating with the pressure air source 5 in the center
However, on both sides there are the first and second pilot chambers 3.
First and second pilot ports 60 and 61 communicating with air pumps 9 and 40 are provided, and first and second exhaust ports 62 and 63, which are open to the atmosphere, are provided on both sides of the pilot ports 60 and 61, respectively. The end of the spool 55 includes a return spring housing chamber 56 and a detent mechanism section 57.
The tips of the solenoids 51 and 52
It is in contact with the push rod at the tip.

The spool 55 of the pilot valve 50 has a small diameter portion in a penetrating portion of the return spring housing chamber 56;
The spring receiver 65 that is slidably inserted into the small diameter portion holds the spool 55 at the neutral position shown in the figure by the biasing force of the return spring 66 that is contracted in the return spring storage chamber 56. It is energizing.

On the other hand, the detent mechanism section 57 includes a plurality of balls 67, which are urged toward the center of the spool 55 by a spring (not shown).
The ball and a locking groove 68 formed around the spool 55 constitute a mechanical detent mechanism that temporarily engages and holds the spool 55.

When the first solenoid 51 is excited, the spool 55 is connected to a pressure port 59, a first pilot port 60, a second pilot port 61 and a second pilot port 62.
When the second solenoid 52 is excited, it slides to a first switching position where the pressure port 59 and the second pilot port 61, and the first pilot port 60 and the first exhaust port 62 are communicated. When both solenoids 51 and 52 are de-excited, it returns to the neutral position by the biasing force of the return spring 66, closing the pressure port 59 and opening the pilot port 60.
0, 61 communicate with exhaust ports 62, 63.

Note that when the spool 55 is in the neutral position,
As shown in FIG. 2, the exhaust ports 62 and 63 are
Both are formed so that the land of the spool 55 narrows the opening area.

Next, the operation of the above embodiment will be explained with reference to FIGS. 1 to 3.

In FIGS. 1 and 2, both solenoids 51 and 52 are de-energized and the pilot valve 50 is in the neutral position, so that the pilot ports 60 and 61 communicate with the exhaust ports 62 and 63 (see FIG. 2). ,
The main valve 20 is also in the neutral position, the supply valve section 25 and the vacuum pressure valve section 26 are closed, and the suction pad 3 is in a resting state.

When the first solenoid 51 is excited in this state,
The spool 55 is pushed by the push rod and slides to the right in the figure, switching to the first switching position, so that the pressure port 59 and the first pilot port 60
The second pilot port 61 and the second exhaust port 63 continue to communicate with each other. As a result, pressurized air is supplied to the first pilot chamber 39 through the first pilot port 60 and the first pilot passage 41, while the pressure air is supplied to the second pilot chamber 4.
0 communicates with the atmosphere through the second pilot passage 42, second pilot port 61, and second exhaust port 63, the piston 38 and rod 35 of the main valve 20 move upward, and the vacuum pressure valve body 33 releases the vacuum. Open the pressure valve seat 32. Therefore, output port 23
The vacuum pressure port 24 communicates with the suction pad 3.
Vacuum pressure acts on the

In this case, the spring receiver 65 fitted into the small diameter portion of the spool 55 is maintained in contact with the inner wall of the return spring housing chamber 56. Further, since the balls 67, . . . are pushed into the locking grooves 68 when the spool 55 is in the first switching position, the first switching position of the spool 55 is maintained by the detent mechanism. Therefore, even if the solenoid 51 is demagnetized due to a power outage or the like, the spool 55 remains in the first switching position, and the vacuum pressure valve body 33 of the main valve 20 is also in the open state of the vacuum pressure valve seat 32. , the suction pad 3 does not lose its suction holding power.

Next, when the first solenoid 51 is de-energized and the second solenoid 52 is energized, the push rod presses the spool 55 and the balls 67, etc. are released from the locking groove 68 against the biasing force of the spring. , the holding of the position of the spool 55 by the detent mechanism is released, and the spool 55 slides to the left. As a result, when the spool 55 reaches the neutral position, the first pilot port 60 communicates with the first exhaust port 62, and the air in the first pilot chamber 39 of the main valve 20 is discharged to the atmosphere. returns to the neutral position, while the spool 55 further slides past the neutral position to the second switching position, placing the pressure port 59 and the second pilot port 61 in communication. In this case, since the spring receiver 65 slides to the left together with the spool 55, the return spring 66 is compressed.

When the spool 55 switches to the second switching position,
Pressure port 59 and second pilot port 61, and first pilot port 60 and first exhaust port 6
2 communicate with each other, so that pressurized air is supplied to the second pilot chamber 40 of the main valve 20 through the second pilot port 61 and the second pilot passage 42.
As a result, the piston 38 and rod 35 of the main valve 20 move downward, the vacuum pressure valve body 33 closes the vacuum pressure valve seat 32 by the urging force of the main valve spring 34, and the supply valve body 30 closes the supply valve seat 32. Since the seat 29 is opened, pressurized air is supplied from the supply port 22 to the output port 23, and the suction and holding of the article by the suction pad is released.

Note that the exhaust ports 62 and 63 are formed with a narrow opening area at the neutral position, and the spool 5
5 passes through the neutral position, it is immediately closed, so that the pressure port 59 is connected to the pilot port 60,
Pressure air supplied to 61 is supplied to exhaust ports 62, 6
3.No leakage.

Thereafter, when the second solenoid 52 is de-energized, the spool 55 is moved to the compressed return spring 6.
6 returns to the neutral position and the second pilot port 61 and second exhaust port 63 communicate with each other, so that the pilot air in the second pilot chamber 40 of the main valve 20 passes through the second pilot passage 42. released into the atmosphere. Therefore, the piston 38 and the rod 35 are moved upward by the urging force of the main valve spring 31, and the supply valve body 30 closes the supply valve seat 29 and returns to the position shown in FIG. The suction pad 3 is cut off and becomes inactive.

Note that the main valve described above is not limited to the illustrated embodiment, as long as it switches the output port between the supply port and the vacuum pressure port.

[Effects of the invention] The invention provides that when the valve member of the pilot valve is in the first switching position, the output port of the main valve is in communication with the vacuum pressure port, and the suction pad is suctioning and holding an article, Since the mechanical detent mechanism holds the valve member, even if one solenoid that operates the pilot valve is demagnetized due to a power outage or the like, the suction pad's ability to attract and hold articles will not be lost.

Furthermore, since the valve member of the pilot valve does not stop at the neutral position when sliding from the first switching position to the second switching position, the valve body of the main valve also does not stop at the neutral position. , unnecessary operations of the pilot valve and main valve can be eliminated.

Furthermore, since the holding and releasing of the valve member by the detent mechanism provided in the pilot valve is performed by the other solenoid that switches the valve member, there is no need for a solenoid for releasing the detent as in the case of Fig. 5. , not only can the vacuum pressure control valve be made simple and inexpensive, but by demagnetizing the other solenoid, the supply valve section of the main valve cuts off communication between the output port and the supply port, so that the vacuum pressure control valve can be made simple and inexpensive. Since the supply of pressurized air to the suction pad is stopped, waste of air can be prevented.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional front view of the main part of the embodiment of the present invention, Fig. 2 is a longitudinal sectional front view of the same pilot valve, Fig. 3 is an explanatory diagram of the operation of the embodiment of the invention, and Fig. 4 is a conventional vacuum pressure FIG. 5 is an explanatory diagram of the operation of the control valve, and FIG. 5 is an explanatory diagram of the operation of the prior art. 3... Suction pad, 4... Vacuum source, 5... Pressure air source, 20... Main valve, 22... Supply port, 2
3...Output port, 24...Vacuum pressure port, 25
... Supply valve section, 26 ... Vacuum pressure valve section, 27 ... Drive section, 50 ... Pilot valve, 51, 52 ... Solenoid, 54 ... Body, 55 ... Spool,
57...Mechanical detent mechanism section.

Claims (1)

[Scope of Claim for Utility Model Registration] A vacuum pressure control valve comprising a main valve and an electromagnetically driven pilot valve for driving the main valve, the main valve having an output port communicating with a suction pad connected to a vacuum source. a vacuum pressure valve section and a supply valve section, each having a switching position that communicates or closes the vacuum pressure port that communicates with the output port and a switching position that communicates or closes the supply port that communicates the output port with the pressurized air source;
The pilot valve body is also provided with a drive unit that opens and closes these valve parts, and the pilot valve body is provided with a vacuum pressure valve part that opens the vacuum pressure valve part to the main valve drive part when the valve member is in a first switching position by excitation of one solenoid. A flow path is provided to supply pilot fluid for the purpose of energizing the second solenoid.
At the switching position, the driving section of the main valve is provided with a flow path for supplying pilot fluid to close the vacuum pressure valve section and open the supply valve section at the same time, and even if one solenoid is demagnetized, the valve member remains in the above position. A vacuum pressure control valve characterized in that it is provided with a detent mechanism section that maintains it in a first switching position.