JP3043843B2 - Vacuum generation unit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum generating unit for supplying a negative pressure to a working device such as a suction pad, and more particularly to a vacuum generating unit for supplying and shutting off a negative pressure of a vacuum generating unit.
The present invention relates to a unit for vacuum generation performed by using an electromagnetic pilot valve switched by two solenoids.

[0002]

2. Description of the Related Art For example, a vacuum generating unit is used as a vacuum generating source in a suction pad. The vacuum generating unit generally includes an ejector or a vacuum pump that generates a negative pressure, a control valve that supplies or shuts off the negative pressure, and a pilot valve that controls the control valve.

[0003] The vacuum generating unit thus configured switches the control valve by the pressure generated under the action of the pilot valve, thereby supplying or shutting off the pressurized fluid to the ejector. And other work equipment. That is, when the suction pad is connected to the vacuum generating unit and used, a pressure fluid is supplied from the control valve to the ejector to generate a negative pressure, and the suction pad sucks the workpiece by the negative pressure. Further, by switching the pilot valve, the supply of the pressurized fluid to the ejector is shut off, and the work is released from the suction pad.
In the case of a vacuum pump, negative pressure is supplied or cut off by a control valve, and control is similarly performed.

[0004]

However, in the above conventional technique, when the control valve is driven and controlled by a spring offset type pilot valve using a single solenoid, the following problems occur.

[0005] That is, if a power failure occurs while the work is being suctioned and conveyed by the suction pad, the operating state of the pilot valve is switched from on to off, and the pilot valve body is displaced under the action of the spring. Therefore, the supply of the pressure fluid to the ejector or the negative pressure from the vacuum pump is interrupted, and the negative pressure of the suction pad disappears, and the work drops.

An object of the present invention is to provide a vacuum generating unit capable of maintaining the operating state even if a power failure occurs during the operation of the vacuum generating unit. Aim.

[0007]

In order to achieve the above object, the present invention comprises a control valve for supplying or shutting off a negative pressure, first and second solenoids, An electromagnetic pilot valve that controls the control valve to supply a negative pressure under the driving action of the first solenoid and controls the control valve under the driving action of the second solenoid to cut off the supply of the negative pressure; , Is provided.

[0008]

In the vacuum generating unit according to the present invention, the electromagnetic pilot valve is driven by the first and second solenoids,
This controls the control valve. In this case, when a power failure occurs, only the first and second solenoids are turned off, and the state of the pilot valve itself does not change. Therefore, the state before the power failure is maintained also in the control valve, and for example, the negative pressure state by the ejector and the vacuum pump is maintained.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A vacuum generating unit according to the present invention will be described.
The first embodiment will be described in detail below with reference to the accompanying drawings.

FIG. 1 shows a schematic external view of a vacuum generating unit 10 according to the present embodiment, and FIG. 2 shows an equivalent circuit of the vacuum generating unit 10.

The vacuum generating unit 10 basically includes an electromagnetic valve section 12 as an electromagnetic pilot valve,
It comprises a valve mechanism section 14 as a control valve controlled by the manifold, a manifold 16, an ejector 18, a filter section 20, a detection section 22, and a vacuum port section 24.

3 and 4, an electromagnetic valve portion 12 is mounted on an upper portion of the valve mechanism portion 14, and is disposed such that one side portion of the manifold 16 is in contact with one side portion of the valve mechanism portion 14. Have been. A supply port 26, a pilot valve supply port 28, a vacuum break port 30, a pilot valve exhaust port 3
2 are formed. 2 inside the valve mechanism 14
A port 2 position type supply valve 36 and a vacuum break valve 38, and a flow control valve 34 is provided in the middle of a passage 56 communicating from the vacuum break valve 38 to a vacuum port 70 described later. , 38, ports 26, 2
Passages are formed to connect the solenoid valves 8, 30, 32, the electromagnetic valve portion 12, and the manifold 16. Pilot valve supply port 28
Check valves 39a, 39b are provided at both ends of the passage communicating with
It has. The check valves 39a and 39b are used to extend the supply pressure holding time to the valve body when the supply of the compressed air is stopped.

The electromagnetic valve section 12 installed above the valve mechanism section 14 includes a supply valve 36 which constitutes the valve mechanism section 14,
And two-position 5-port first pilot valve 40 and second pilot valve 4 for turning on and off vacuum release valve 38
2. It has a third pilot valve 44. Pilot valve 4
The internal structures of 0, 42 and 44 will be described later.

The manifold 16 has a valve mechanism 1 on one side.
4 and the other side is in contact with the ejector 18. A supply passage 46, a pilot valve supply passage 48, a vacuum break passage 50, and a pilot valve exhaust passage 52 are formed inside the manifold 16, and a passage 54 communicating the supply valve 36 and the ejector 18, a vacuum break valve 38. And a passage 56 communicating with a vacuum port 70 described later. Check valves 57a and 57b are provided at both ends of the pilot valve supply passage 48. Check valve 57a, 5
Reference numeral 7b is for extending the supply pressure holding time to the valve body when the supply of the compressed air is stopped.

A side surface of the ejector 18 is disposed on a side surface of the manifold 16 so as to be in contact therewith. The ejector 18 is formed of a rectangular body, and has a nozzle portion 58 having a predetermined diameter and a diffuser portion 60 connected to the nozzle portion 58 therein.
Communicates with the vacuum generator 61.

An opening 62 communicating with a pilot valve exhaust passage 52 of the manifold 16 is formed on one side of the ejector 18. On the other hand, the diffuser section 60 has a box shape with one side opened, and this opening is closed by a lid member 64 having a plurality of cylindrical slits 63 formed at equal intervals. A silencer 66 is mounted between the opening 62 and the lid member 64.

On the other side of the ejector 18, a detecting section 22 and a vacuum port section 24 are mounted. The detection unit 22 has a box shape and has a vacuum switch 6 therein.
8 are provided. The vacuum switch 68 is preferably formed of a resistance type or capacitance type semiconductor pressure sensor, and detects a negative pressure generated in the vacuum generation unit 61 through a passage 72 communicating with a vacuum port 70 described later to control the working equipment. Emits a signal to In addition, a substrate inside the detection unit 22, for example, a flexible substrate, obtains an output signal of an electronic pressure sensor using a microcomputer or a one-chip microcomputer, and sets a pressure, adjusts a pressure,
Alarm generation / stop, ON / OFF operation, hysteresis removal,
It has a mode switching function, a failure prediction function of an internal state monitor of the vacuum generation unit, and the like, and can control the operation including the operation state of the entire vacuum generation unit. It is possible to include a driver in the vacuum detection unit and the vacuum generation unit, and also to perform predictive control of the suction state using fuzzy logic. As another control method, pre-operation is automatically performed in advance according to a program, on / off setting is automatically set, and after operation, base pressure fluctuation is detected by another sensor and fed back to automatically set the optimum value. It may be moved to a value. For example, the base pressure and the detection signal may be set to 50%. In addition, a digital display device such as a liquid crystal (color LCD) and a light emitting diode (LED) (not shown) may be provided. A filter 74 is mounted on a boundary surface between the detection unit 22 and the vacuum port unit 24.

The vacuum port 24 has a rectangular shape and is provided on a check valve 76 formed of a flexible member from one side of the ejector 18, a passage 78 communicating with the filter 20, and another side. Having a vacuum port 70,
A passage 72 directed from the vacuum port 70 to the detection unit 22
have.

The filter section 20 is fixed to the vacuum port section 24. A filter body 80 is provided inside the filter unit 20, and the filter unit 20 is connected to a vacuum port 2 by a stud 82 having a knob 84.
4 is fixed. Therefore, the filter main body 80 can be replaced by screwing the knob 84.

Next, the internal structure of the pilot valves 40, 42, 44 will be described. Pilot valves 40, 42, 44
Is connected to a passage formed inside the valve mechanism 14 by a first interface 86 and a second interface 88 mounted on the upper part of the valve mechanism 14. First, the first pilot valve 40 will be described with reference to FIG. 2 and FIGS.

The first pilot valve 40 includes a packing 8 together with a second pilot valve 42 and a third pilot valve 44.
9 is placed on the upper part of the second interface 88 with the interposition 9 therebetween (see FIGS. 3 and 4). The first pilot valve 40 includes an electromagnetic valve 90a, a connection portion 92a, and a pilot switching valve 94.
and a cover member 98 is provided at an end of the pilot switching valve 94a. A through hole 100 through which a pilot valve body 96a is inserted is formed in the center of the pilot switching valve 94a.
00, the first port 102a, the second port 10
4a, third port 106a, fourth port 108a, fifth port
The port 110a communicates. The first port 102a and the fifth port
The port 110 a communicates with the pilot valve exhaust port 32 of the valve mechanism 14 and the pilot valve exhaust passage 52 of the manifold 16. The second port 104a is the supply valve 3
The first pressure chamber 112 communicates with the first pressure chamber 112 through a passage 114. The third port 106 a communicates with the pilot valve supply port 28 of the valve mechanism 14 and the pilot valve supply passage 48 of the manifold 16. The fourth port 108a communicates with the second pressure chamber 116 of the supply valve 36 through a passage 118 (see FIG. 4). First through fifth holes are formed on the inner surface of the through hole 100.
A ring-shaped recess corresponding to the ports 102a to 110a is formed. In the upper part of the through hole 100, a third
A passage 120 is defined in communication with the ring-shaped recess corresponding to the port 106a.

A cover member 98 connected to one end of the pilot switching valve 94a has a cylindrical recess 122 which is connected to the through hole 100 and in which one end of the pilot valve body 96a slides.
a is formed. In the recess 122a, a hole 1 communicating with a recess 124b of a second pilot valve 42 described later is provided.
25 are formed.

A connecting portion 92a connected to the other end of the pilot switching valve 94a has a cylindrical recess 126 in which the other end of the pilot valve body 96a is slidably connected to the through hole 100.
Is formed. Also, this connection portion 92a has a hole 1
The valve 128 for manual operation is inserted into the hole 128. The valve element 130 is
The projection is urged by the spring 134, and the amount of projection is regulated by the stopper 138. When the first pilot valve 40 is malfunctioning, the valve body 130 is pressed by a finger to displace the valve body 130 downward, so that the passage 120 of the pilot switching valve 94a and the recess 12
6. This is for confirming the operating state of the pilot valve body 96a by communicating with the passage 140 between the holes 128. The hole 128 communicates with the solenoid valve 90a at two locations above and below the valve element 130. In the lower part of the connection portion 92a,
A passage 144 communicating the solenoid valve 90a and the recess 142 of the pilot switching valve 94a is defined.

Electromagnetic valve 90a connected to connecting portion 92a
Has a coil 146 and a movable iron core 148 at the top. The movable iron core 148 includes packings 150 and 152. On the connection portion 92a side of the solenoid valve 90a, the first
A passage 154, a second passage 156, and a third passage 158 are formed. The opening 160 of the first passage 154 is opened and closed by the packing 150 of the movable iron core 148, and
The opening 162 of the passage 156 is configured to be opened and closed by the packing 152 (see FIG. 7). Opening 16
When opening 0, the first passage 154 communicates with the third passage 158 via the passage 164 and the ring-shaped space 166.
On the other hand, when the opening 162 is opened, the second passage 156 and the third passage 158 communicate with each other.

The second pilot valve 42 will be described with reference to FIGS. The same components as those of the first pilot valve 40 are denoted by the same reference numerals, and a detailed description thereof will be omitted. The second pilot valve 42 is a first pilot valve 4
It is mounted on the upper part of the valve mechanism section 14 with the packing 89 and the first and second interfaces 86 and 88 interposed therebetween. A fixed pilot valve body 96b is inserted through the through hole 100 of the pilot switching valve 94b. Second port 104b, fourth port 1 of pilot switching valve 94b
08b is shut off from the valve mechanism 14 by the packing 89 and is not used. Another configuration is the pilot switching valve 9
This is substantially the same as 4a. A lid member 98 is connected to one end of the pilot switching valve 94b in the same manner as the first pilot valve 40. The first pilot valve 40 and the second pilot valve 42 communicate with each other through the hole 125 of the cover member 98.

The third pilot valve 44 will be described with reference to FIGS. The same components as those of the first pilot valve 40 are denoted by the same reference numerals, and a detailed description thereof will be omitted. The third pilot valve 44 is placed adjacent to the first pilot valve 40 above the valve mechanism 14 with the packing 89 and the first and second interfaces 86 and 88 interposed therebetween. Second port 104c of pilot switching valve 94c
Communicates with the first pressure chamber 196 of the vacuum break valve 38 via a passage 198. The fourth port 108c communicates with the second pressure chamber 200 of the vacuum break valve 38 via a passage 202 (see FIG. 4). Recess 2 formed in lid member 204
The pilot valve body 96 c fits into the valve 06, and the recess 206 communicates with the passage 120.

Next, the operation of the vacuum generating unit 10 configured as described above will be described.

However, this operation will be described in connection with the manifold 1
6, a plurality of vacuum generating units 10 are connected in series and the port of the valve mechanism 14 is closed. Therefore, supply of compressed air, supply pressure for driving the pilot valve, vacuum breaking pressure, pilot valves 40 and
2, 44 and the exhaust from the ejector 18
This operation is described only through the manifold 16.

A case in which a working device, for example, a suction pad is connected to the vacuum port 70 and a negative pressure is applied thereto will be described with reference to an equivalent circuit shown in FIG.

First, a compressed air supply source such as a compressor (not shown) is energized, and the compressed air passes through the pilot valve supply passage 48 of the manifold 16, passes through the internal passage of the valve mechanism section 14, and flows into the third pilot valve 40 of the first pilot valve 40. Port 106a is reached. When the solenoid valve 90a is inactive, the third port 106a communicates with the fourth port 108a (see FIG. 5). Therefore, the pressure fluid flows through the fourth port 10
8a via the passage 118 through the second pressure chamber 11 of the supply valve 36.
6, the supply valve 36 is closed (see FIG. 4). On the other hand, the pressure fluid flows from the third port 106a to the passage 121,
The first of the solenoid valve 90a is inserted through the hole 128 of the connecting portion 92a.
Passage 154 is reached.

Therefore, when the work is sucked and conveyed by the suction pad, the solenoid valve 90a is energized. That is, when the coil 146 is excited, the movable core 1
48 is displaced upward. Therefore, the packing 150 is displaced upward, the opening 160 is opened, and the first passage 154 is opened.
Communicates with the third passage 158 via the passage 164 and the ring-shaped space 166 (see FIG. 6). As a result, the compressed air reaches the third passage 158, and further the hole 1 of the connecting portion 92a.
After reaching the recess 126 through the passage 140 below the lower part 28, the pilot valve main body 96a is displaced leftward in the drawing (see FIG. 6). At this time, the air in the concave portion 122a of the lid member 98 reaches the concave portion 124b of the second pilot valve 42 from the concave portion 124a via the hole 125. Further, the air is
The solenoid valve 90 passes through the through hole 192 of the pilot valve body 96b of the second pilot valve 42 and the passage 140 of the connecting portion 92b.
b, reaches the fifth port 110b from the opening 162 through the second passage 156, the passage 144 of the connecting portion 92b, the recess 142 of the pilot switching valve 94b, and the internal passage of the valve mechanism portion 14. Is discharged to the pilot valve exhaust passage 52 of the manifold 16 (see FIG. 8).

As described above, the pilot valve body 96a of the first pilot valve 40 is displaced leftward in the drawing,
The port 106a communicates with the second port 104a,
The port 108a communicates with the fifth port 110a (see FIG. 6). Therefore, the pressure fluid supplied to the third port 106a reaches the first pressure chamber 112 from the second port 104a via the passage 114, and displaces the supply valve 36 to the left in the drawing to open the supply valve 36. (See FIG. 4). At this time, the air in the second pressure chamber 116 is
Through the fourth port 108a and the fifth port 110a.
A is discharged from a into the pilot valve exhaust passage 52 of the manifold 16 (see FIGS. 4 and 6).

Since the supply valve 36 is thus opened, the supply passage 46 of the manifold 16 communicates with the ejector 18 to supply compressed air to the ejector 18 (see FIG. 2). In this way, a negative pressure is generated in the ejector 18, and the check pressure 76 formed of a flexible member is opened by the negative pressure to suck the air from the suction pad to suck the work.
That is, due to the negative pressure, the air on the vacuum port 70 side is sucked into the diffuser unit 60 via the filter unit 20 for removing dust, the passage 78, and the vacuum generating unit 61.

At this time, the vacuum switch 68 of the detecting section 22 measures the negative pressure at the vacuum port 70 through the passage 72 communicating with the detecting section 22 from the vacuum port 70, and controls the working equipment with the output signal. I do.

On the other hand, the vacuum port 7 is
The compressed air ejected from the nozzle portion 58 and the air sucked from the nozzle portion 58 are supplied from the diffuser portion 60 to the lid member 6.
4, the silencer 66 and the opening 6
2, the pilot valve exhaust passage 52 of the manifold 16
(See FIG. 3).

Next, when the work is to be detached from the suction pad after the conveyance, the operation is performed as described below. That is, the solenoid valve 90a of the first pilot valve 40 is deactivated, and the solenoid valve 90b of the second pilot valve 42 and the solenoid valve 90c of the third pilot valve 44 are energized. First pilot valve 40
When the electromagnetic valve 90a is deactivated, the excited state of the coil 146 is released, and the movable iron core 148 is displaced downward. Therefore, the upper packing 150 closes the opening 160, and the second passage 156 and the third passage 158 communicate with each other (see FIG. 7). On the other hand, when the solenoid valve 90b of the second pilot valve 42 is energized, the solenoid valve 90b is connected from the third port 106b of the pilot switching valve 94b through the passage 121 and the connection portion 92b in the same manner as the solenoid valve 90a of the first pilot valve 40. First
The compressed air that has reached the passage 154 reaches the third passage 158 from the opening 160 via the passage 164 and the ring-shaped space 166 (see FIG. 9). Further, the compressed air is supplied to the connecting portion 9.
2b, through the through hole 192 of the pilot valve body 96b, and from the recess 124b of the lid member 98 to the hole 1
The first pilot valve 40 reaches the recess 124a of the lid member 98 of the first pilot valve 40 via 25, and displaces the pilot valve main body 96a of the first pilot valve 40 rightward in the drawing (see FIG. 5). With this displacement, the connection portion 9 of the first pilot valve 40
The air in the recess 126 of FIG.
0a reaches the third passage 158. Since the third passage 158 and the second passage 156 communicate with each other, the air reaches the recess 142 of the pilot switching valve 94a from the second passage 156 via the passage 144 of the connecting portion 92a. The air that has reached the recess 142 as described above is
To the right and the pilot valve body 96
a of the fifth port 110 via the check seal 182 of FIG.
The gas is exhausted from a into the pilot valve exhaust passage 52 of the manifold 16 (see FIG. 7).

As described above, the pilot valve body 96a of the first pilot valve 40 is displaced rightward in FIG.
Port 106a communicates with fourth port 108a, and second port 104a communicates with first port 102a. Therefore, the pressure fluid supplied to the third port 106a flows from the fourth port 108a through the passage 118 to the second pressure chamber 1
At 16 the supply valve 36 is closed (see FIG. 4). At this time, the air in the first pressure chamber 112 reaches the second port 104a via the passage 114, reaches the pilot valve exhaust passage 52 of the manifold 16 from the first port 102a, and is discharged. Therefore, no compressed air is supplied to the ejector 18 and no negative pressure is supplied to the suction pad (see FIG. 2).

When the solenoid valve 90c of the third pilot valve 44 is energized, the third valve 106c is connected to the third port 106c of the pilot switching valve 94c through the passage 121 and the connecting portion 92c in the same manner as the first solenoid valve 90a. The compressed air that has reached the first passage 154 reaches the third passage 158 via the passage 164 (see FIG. 11). Further, the compressed air is supplied to the connecting portion 92.
Through the passage 140 of FIG. on the other hand,
The compressed air supplied from the third port 106c passes through the passage 1
Through 20, it reaches the concave portion 206 of the lid member 204. As described above, the compressed air that has reached both ends of the pilot valve body 96c has a difference in the pressing force due to the difference in the pressure receiving area between the two ends of the pilot valve body 96c (the connection portion 92c side> the lid member 204 side). The pilot valve body 96c of the third pilot valve 44 is displaced leftward in the drawing (see FIG. 11).

As described above, the pilot valve body 96c of the first pilot valve 40 is displaced leftward in the drawing,
The port 106c communicates with the second port 104c, and the fourth port 108c communicates with the fifth port 110c. Therefore, the pressure fluid supplied to the third port 106c flows from the second port 104c to the first pressure chamber 1 via the passage 198.
At 96, the vacuum break valve 38 is opened (see FIG. 4).
At that time, the air in the second pressure chamber 200 reaches the fourth port 108c via the passage 202, reaches the pilot valve exhaust passage 52 of the manifold 16 from the fifth port 110c, and is discharged. Therefore, the compressed air is supplied to the manifold 1
The vacuum pressure reaches the vacuum port 70 from the vacuum breaking passage 50 of FIG. 6 via the vacuum breaking valve 38 and the passage 56, and quickly releases the negative pressure state of the suction pad to separate the work (see FIG. 2). A switching valve is provided between the silencer 66 and the pilot valve exhaust passage 52 or between the ejector 18 and the check valve 76,
By opening the switching valve during the generation of the vacuum and closing the switching valve during the breaking of the vacuum, the workpiece can be more reliably separated.

After the suction pad has detached the work, the solenoid valve 90c of the third pilot valve 44 is deactivated until the suction pad sucks the work again. Solenoid valve 90a
Similarly, the coil 146 of the solenoid valve 90c is released from the excited state, and the movable iron core 148 is displaced downward (see FIG. 10). As a result, the upper packing 150 is
0 is closed, and the first passage 154 and the passage 164 are shut off. Further, since the lower packing 152 is also displaced downward, the second passage 156 and the third passage 158 are communicated with each other.
Therefore, the third passage 158 is connected to the passage 1 of the connection portion 92c.
No compressed air is supplied to the concave portion 126 through the third port 106 and the passage 1 is connected to the third port 106c of the pilot switching valve 94c.
The pilot valve body 96c is displaced rightward in the drawing by compressed air that reaches the concave portion 206 of the lid member 204 via 20 (see FIG. 10).

As described above, the pilot valve body 96c of the first pilot valve 40 is displaced rightward in FIG.
Port 106c communicates with fourth port 108c, and second port 104c communicates with first port 102c. Therefore, the pressure fluid supplied to the third port 106c flows from the fourth port 108c through the passage 202 to the second pressure chamber 2c.
When the pressure reaches 00, the vacuum break valve 38 is displaced rightward to close the vacuum break valve 38 (see FIG. 4). At that time, the air in the first pressure chamber 196 flows through the second port 1 through the passage 198.
04c and manifold 1 from the first port 102c
The exhaust gas reaches the pilot valve exhaust passage 52 of No. 6 and is discharged. Since the vacuum break valve 38 is closed, compressed air does not reach the vacuum port 70 from the vacuum break passage 50 of the manifold 16 (see FIG. 2). In this way, it is possible to prevent the compressed air from being wastefully used, for example, after the suction pad has separated the work and before the work is again suctioned.

By repeating this series of operations, the suction pad is transported. Next, a case where a power failure occurs during the transfer of a workpiece will be described. During the transfer of the work, only the solenoid valve 90a of the first pilot valve 40 is energized, the other solenoid valves 90b and 90c are deactivated, and the supply valve 36
Is opened, and the vacuum break valve 38 is closed. FIG. 2 shows the state of the first to third pilot valves 40, 42, 44 in this case. If a power failure occurs in this state, the solenoid valve 90a of the first pilot valve 40 is deactivated. Therefore, the first passage 154 and the third passage 158 of the solenoid valve 90a are shut off, and the second passage 156 and the third passage 158 are connected (see FIG. 5). Therefore, compressed air is not supplied from the third passage 158 to the recess 126 via the passage 140. However, since the solenoid valve 90b of the second pilot valve 42 is also deenergized, the first passage 154 of the solenoid valve 90b is turned off.
And the third passage 158 are also shut off (see FIG. 8). Therefore, the third passage 158 of the solenoid valve 90b is connected to the connection portion 92b.
Passage 140, through-hole 192 in pilot valve body 96b
Compressed air is not supplied to the concave portion 124b of the lid member 98 via. That is, the hole 1 is formed from the recess 124 b of the lid member 98.
Compressed air is not supplied to the recess 124a through 25. Therefore, in the first pilot valve 40,
No pressing force acts on either side of the pilot valve main body 96a, and the pilot valve main body 96a
Does not displace. For this reason, even if a power failure occurs, the supply valve 36 maintains the open state, and the supply passage 4 of the manifold 16 is opened.
Compressed air is supplied from 6 to the ejector 18 to generate a negative pressure, and the suction state of the suction pad is maintained. Explaining with the fluid circuit diagram, the state of FIG. 2 is maintained.

Here, an example using the ejector 18 has been described, but a vacuum pump can also be used. In this case, in this embodiment, the ejector 1
Except for 8, the detection unit 22 and the vacuum port unit 24 are directly connected to the manifold 16 to configure the vacuum generating unit 10 (see FIG. 12). At this time, the supply port 26 of the valve mechanism 14 or the supply passage 46 of the manifold 16
A vacuum pump (not shown) is connected.

As in the example using the ejector 18, the passages 46, 48, 50 and 52 of the manifold 16 are used,
The operation when the ports 26, 28, 30, and 32 of the valve mechanism 14 are closed with screws will be briefly described with reference to FIG.

The negative pressure supplied from the vacuum pump is supplied from the supply passage 46 of the manifold 16 to the supply valve 3 of the valve mechanism 14.
The air is supplied from the vacuum port 70 to the suction pad and the like via the line 6. At this time, the first and second pilot valves 40 and 42 operate in the same manner as in the case where the ejector 18 is used, so that the work can be held even if the suction pad loses power during the suction conveyance of the work.

In the first embodiment, the first pilot valve 40 and the second pilot valve 42 are connected to each other through the hole 125 of the cover member 98 to constitute a double solenoid type electromagnetic pilot valve, and the suction pad holds the work. Even if a power failure occurs during conveyance, the first pilot valve 40 does not switch, so that the negative pressure is continuously supplied, and the suction pad can hold the work. The solenoid valves 90a, 90b, 90c and the connecting portions 92a to 92c of the pilot valves 40, 42, 44 are made of the same member, and when forming a double solenoid, a lid member 98 is used. 9
6a, the non-displaceable pilot valve body 96b is inserted into the other. When a single solenoid is configured, the lid member 204 is used to displace the pilot valve body 9 that can be displaced.
6c is inserted. That is, it is possible to configure a double solenoid by only partially replacing an existing part for a single solenoid.

Next, a second embodiment will be described. First
The same components as those of the embodiment are denoted by the same reference numerals,
A detailed description thereof will be omitted.

In the second embodiment, the solenoid valve section 12 is constituted by a double solenoid type solenoid pilot valve comprising only the first pilot valve 40 and the second pilot valve 42.

The second port 104 of the first pilot valve 40
a is the first pressure chamber 11 of the supply valve 36 through the passage 114.
2 and a vacuum break valve 3 through a passage 202.
8 communicates with the second pressure chamber 200. The fourth port 108a of the first pilot valve 40 communicates with the second pressure chamber 116 of the supply valve 36 through the passage 118 and the passage 1
It communicates with the first pressure chamber 196 of the vacuum break valve 38 via 98 (see FIG. 4).

In the vacuum generating unit 10 configured as described above, in order to suck and convey a work by the suction pad, first, the solenoid valve 90a of the first pilot valve 40 is energized, and the second pilot valve 42 is turned on. The solenoid valve 90b is deactivated. As in the first embodiment, the pilot valve body 96a of the first pilot valve 40 is displaced to the left in the drawing, and the third port 1
06a, the second port 104a, and the fourth port 108a
And the fifth port 110a communicate with each other (see FIG. 6). Therefore, compressed air flows from the third port 106a to the second port 1
04a, the first pressure chamber 1 of the supply valve 36 through the passage 114
12, and reaches the second pressure chamber 200 of the vacuum break valve 38 via the passage 202 (see FIG. 4). That is, the supply valve 36 is opened, and the vacuum break valve 38 is closed. On the other hand, the air in the second pressure chamber 116 of the supply valve 36 and the air in the first pressure chamber 196 of the vacuum break valve 38 reach the fifth port 110a from the fourth port 108a and are discharged from the pilot valve exhaust passage 52 of the manifold 16. Is done. As described above, compressed air is supplied from the supply passage 46 of the manifold 16 to the ejector 18 via the supply valve 36, and a negative pressure is supplied to the suction pad to suck and convey the work (see FIG. 14).

To release the work from the suction pad,
In the vacuum generating unit 10, the second pilot valve 42
The solenoid valve 90b of the first pilot valve 40 is deenergized. As in the first embodiment, the pilot valve main body 96a of the first pilot valve 40 is displaced rightward in the drawing, and the third port 106a and the fourth port 108a and the first port 102a and the second port 104a communicate (FIG. 5). Therefore, the compressed air is supplied to the third port 106a.
From the second pressure chamber 116 of the supply valve 36 through the passage 118.
And the first pressure chamber 19 of the vacuum break valve 38 through the passage 198.
6 (see FIG. 4). That is, the vacuum break valve 38
Is opened, and the supply valve 36 is closed. On the other hand, the air in the first pressure chamber 112 of the supply valve 36 and the air in the second pressure chamber 200 of the vacuum break valve 38 reach the first port 102 a from the second port 104 a and are discharged from the pilot valve exhaust passage 52 of the manifold 16. (See FIG. 5). As described above, compressed air is supplied to the vacuum port 70 from the vacuum breaking passage 50 of the manifold 16 via the vacuum breaking valve 38, and compressed air is supplied to the suction pad to separate the work (see FIG. 14).

The work is sucked and conveyed by repeating these two states. In the event of a power outage,
As in the case of the embodiment, the work is held in both the suction state and the vacuum break state.

Also in this case, the supply port 2 of the valve mechanism 14
6, or by connecting a vacuum pump to the supply passage 46 of the manifold 16 and removing the ejector 18 in the same manner as in the first embodiment, it is possible to use a vacuum pump (FIG. 15).
reference).

The second embodiment has the same effect as the first embodiment. In this embodiment, the first pilot valve 40 and the second pilot valve 42 can be used, and the state can be maintained in any of the suction state and the vacuum breaking state.

[0055]

According to the vacuum generating unit of the present invention, the following effects can be obtained.

The electromagnetic pilot valve for driving the control valve is set to one of two positions by the first and second solenoids, and the state can be maintained. Therefore, the electromagnetic pilot valve can be controlled by a power failure or the like. The state is maintained even if it becomes impossible. For example, when a workpiece is transported by operating the suction pad using the electromagnetic pilot valve, it is possible to prevent the workpiece being transported from dropping.

[Brief description of the drawings]

FIG. 1 is a perspective view of an ejector-specific vacuum generating unit according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram of a fluid circuit of a vacuum generating unit of an ejector specification according to a first embodiment of the present invention.

FIG. 3 is a sectional view of an ejector-specific vacuum generating unit according to the first embodiment of the present invention.

FIG. 4 is a partial sectional view of a valve mechanism of the vacuum generating unit according to the first embodiment of the present invention.

FIG. 5 is a sectional view of the first pilot valve according to the first and second embodiments of the present invention when the solenoid valve is deactivated.

FIG. 6 is a sectional view of the first pilot valve of the first and second embodiments according to the present invention when the solenoid valve is energized.

FIG. 7 is a partially enlarged sectional view of a first pilot valve according to the first embodiment of the present invention.

FIG. 8 is a sectional view of the second pilot valve according to the first and second embodiments of the present invention when the solenoid valve is deactivated.

FIG. 9 is a cross-sectional view of the second pilot valve according to the first and second embodiments of the present invention when the solenoid valve is energized.

FIG. 10 is a sectional view of the third pilot valve according to the first embodiment of the present invention when the solenoid valve is deactivated.

FIG. 11 is a cross-sectional view of the third pilot valve according to the first embodiment of the present invention when the solenoid valve is energized.

FIG. 12 is a sectional view of a vacuum generating unit of a vacuum pump type according to the first embodiment of the present invention.

FIG. 13 is an explanatory diagram of a fluid circuit of a vacuum generating unit of a vacuum pump specification according to the first embodiment of the present invention.

FIG. 14 is an explanatory diagram of a fluid circuit of a vacuum generating unit of an ejector specification according to a second embodiment of the present invention.

FIG. 15 is an explanatory diagram of a fluid circuit of a vacuum generating unit of a vacuum pump specification according to a second embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Vacuum generation unit 12 ... Electromagnetic valve part 14 ... Valve mechanism part 16 ... Manifold 18 ... Ejector 20 ... Filter part 22 ... Detection part 24 ... Vacuum port part 40 ... 1st pilot valve 42 ... 2nd pilot valve 44 ... No. 3 Pilot valve 90a to 90c: Solenoid valve 92a to 92c: Connection part 94a to 94c: Pilot switching valve 96a to 96c: Pilot valve body 98, 204: Lid member

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) F16K 31/42 F16K 31/06

Claims (3)

(57) [Claims] A control valve for supplying or shutting off a negative pressure, and a first and a second solenoid, wherein the control valve is controlled by a driving action of the first solenoid to control the negative pressure. And a solenoid pilot valve for controlling the control valve under the driving action of the second solenoid to cut off the supply of negative pressure. 2. The vacuum generating unit according to claim 1, wherein the negative pressure supply source is an ejector. 3. The vacuum generating unit according to claim 1, wherein the negative pressure supply source is a vacuum pump.