JP3439744B2 - Vacuum generator - 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 generator used in a suction and conveyance device for adsorbing and conveying a work by air, and more particularly to a vacuum generator that allows a work to be removed from a vacuum port at high speed. .

[0002]

2. Description of the Related Art A vacuum generator for generating a vacuum by air is often used for an adsorption and conveyance device for adsorbing and conveying a work such as a part by air. These vacuum generators are equipped with a switching valve that controls ON / OFF of the vacuum. When the vacuum is turned on, the work is air-adsorbed and the vacuum is turned off.
There is a product that is formed so as to separate the work when it is turned on. Recently, various manufacturing apparatuses are required to shorten the cycle time and improve work efficiency, so that it is required to shorten the time required for attaching and detaching the work to the vacuum generator.

FIG. 5 is a cross-sectional view showing the configuration of a conventional example of a vacuum generator used for a work attaching / detaching operation. Reference numeral 10 is a compressed air supply port, 40 is an exhaust port, and 50 is a vacuum port for adsorbing a work. 60 is a spool valve, which is moved back and forth in the axial direction by the action of the pilot valve 70,
Communication between the first communication passage connecting the supply port 10 side and the spool valve 60 and the second communication passage connecting the spool valve 60 and the exhaust port 40 side is 0N-OFF depending on the front and rear movement positions. Is configured to control. When the first communication channel 12 and the second communication channel 14 are in communication with each other when a vacuum is generated (workpiece adsorption), the first communication channel 12 and the second communication channel 12 are connected to each other.
The state in which the connection flow path 14 is disconnected is when the vacuum is released (workpiece detachment).

Reference numeral 16 is a cylinder extending in a cylindrical shape from the main body of the vacuum generator. An exhaust port 40 is provided at the tip of the cylinder 16. Reference numeral 18 is a nozzle arranged in the cylinder 16, and 20 is a diffuser spool arranged in front of the nozzle 18. The nozzle 18 is the second communication channel 1
The compressed air sent from No. 4 is ejected at a high speed to suck the vacuum port 50 side into a vacuum. Reference numeral 52 is a cylinder extending in a cylindrical shape from the main body of the vacuum generator. Reference numeral 45 is a communication flow path that communicates between the cylinder 52 and the cylinder 16. The work in which the work is air-adsorbed on the vacuum port 50 side is a function of the compressed air ejected from the supply port 10 toward the exhaust port 40 through the nozzle 18 and the diffuser spool 20, and the cylinder 52 through the communication passage 45. Due to air being sucked from.

[0005]

In the vacuum generator shown in FIG. 5, the pilot valve 70 causes the spool valve 60 to move to the first connecting flow path 12 when the work in which the air suctioned to the vacuum port 50 side is released. It is carried out by moving to a position where the second communication channel 14 is blocked. That is, the injection of compressed air is stopped by disconnecting the first communication flow path 12 and the second communication flow path 14, and the vacuum is passed from the exhaust port 40 side through the diffuser spool 20, the communication flow path 45, and the cylinder 52. It is destroyed and becomes atmospheric pressure, and the adsorption of the work is released. However, in the conventional vacuum generator as shown in FIG. 5, since the diffuser spool having the small diameter inner portion is arranged to efficiently generate the vacuum, the air flow is suppressed when the vacuum is broken. Therefore, there is a problem that the vacuum breaking is prevented from being performed at high speed.

As described above, since the work suction and transfer device using the vacuum generator is required to be able to suck and release the work at a high speed, in the case of the conventional device having the above structure. Had a problem that the work detachment speed was not always sufficient. Therefore, as a device for releasing the work at a higher speed, a method of introducing vacuum into the vacuum circuit by introducing compressed air whose flow rate has been reduced using a flow rate control valve when releasing the work by breaking the vacuum is considered. There is.

FIG. 6 shows an example of a vacuum generator according to a method in which compressed air is flown into a vacuum circuit to release the work when the work is released by breaking the vacuum. The provision of the supply port 10, the exhaust port 40, and the vacuum port 50, and the operation of operating the spool valve 60 with the pilot valve 70 to suck air from the vacuum port 50 will be described with reference to FIG.
The same as the vacuum generator shown in FIG. 2, but a valve for vacuum breaking 80 is provided so that compressed air can be introduced to the cylinder 52 side at the time of vacuum breaking. The difference is that the flow rate is adjusted.

As shown in FIG. 6, the method of introducing compressed air to the vacuum circuit side at the time of breaking vacuum can increase the detaching speed as compared with the method of simply returning to atmospheric pressure, but the operation of transporting small parts. In such a case, it is difficult to adjust the flow rate appropriately so that the work may be blown away when the vacuum is broken. Therefore, it is necessary to separately provide a control unit such as a solenoid valve, and it is difficult to adjust the drive timing of these control units.

Therefore, the present invention has been made to solve these problems, and an object of the present invention is to perform vacuum breaking by returning the pressure to atmospheric pressure so that the work can be performed without delicate adjustment. Provided is a vacuum generator capable of performing a detaching operation in a stable manner and a workpiece detaching operation at a higher speed, and performing an efficient and stable suction and detachment operation of a workpiece. Is what you are trying to do.

[0010]

The present invention has the following constitution in order to achieve the above object. That is, a control unit that controls the ON / OFF control of the supply of compressed air supplied from the supply port, and the compressed air that has been supplied into the cylinder when it is ON is injected from the nozzle and discharged from the exhaust port via the diffuser spool. In the vacuum generator having a vacuum generating section for generating a vacuum and a vacuum port communicating with the vacuum generating section, the diffuser spool is movably provided in the cylinder in the axial direction, and the outer peripheral surface of the diffuser spool is provided. A gap is provided between the inner surface of the cylinder and the inner surface of the cylinder, which serves as an auxiliary flow path for breaking the vacuum, and when the air supply is turned on, the diffuser spool moves to the forward position due to the pressing force of the compressed air, so that the gap is formed. When it is closed and air is sucked from the vacuum port and the air supply is OFF, the diffuser spool moves to the retracted position. The exhaust port, characterized in that was found arranged to be vacuum break through the supplementary passage and an inner diameter portion of the diffuser spool.

Further, the diffuser spool is biased in a direction to move the diffuser spool from the forward position to the backward position, and when the air supply is turned on, the diffuser spool is pushed against the biasing force by the pressing force of the compressed air. It is characterized in that a biasing means for moving the diffuser spool to the retracted position by a biasing force when the air supply is turned off is provided. The outer peripheral surface of the diffuser spool contacts the stopper step formed on the inner peripheral surface of the cylinder at the forward moving position to close the auxiliary flow passage, and the inner peripheral surface of the cylinder at the retracted position. An air packing is provided which is separated from the formed stopper step and connects the auxiliary flow path to the vacuum port. This turns on compressed air
When the −OFF operation is performed, the diffuser spool moves back and forth, and the auxiliary flow path is opened and closed appropriately. In addition, an air introducing port equipped with a filter, which is a separate system from the exhaust port, is provided in communication with the auxiliary flow path of the diffuser spool. As a result, it is possible to prevent the introduction of dirty air when the vacuum is broken, and to easily and quickly break the vacuum. Further, the control unit moves the spool valve forward and backward by a pilot valve that switches the compressed air supplied from the supply port and a compressed air switching operation by the pilot valve, and the cylinder moves from the supply port to the cylinder depending on the moving position of the spool valve. It is characterized in that it is provided to turn on and off the air supply to the.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of a vacuum generator according to the present invention will be described in detail below with reference to the accompanying drawings. 1 and 2 are cross-sectional views showing the internal structure of an embodiment of a vacuum generator. FIG. 1 shows a state when a vacuum is generated, and FIG. 2 shows a state when a vacuum is broken. The vacuum generator according to the present embodiment allows the work to be detached from the vacuum port side by the method of breaking the vacuum by returning to the atmospheric pressure, and the basic configuration is the same as that of the vacuum generator shown in FIG. In the following description, the same components as those in the conventional example are designated by the same reference numerals.

As a connection port, the vacuum generator has a supply port 10 connected to a compressed air source, and an exhaust port 4 for discharging the compressed air sent from the supply port 10 into the main body.
0 and a vacuum port 50 on the side for adsorbing and detaching the work. In this embodiment, the cylinders 16 and 52 are cylindrically extended from the main body, and the exhaust ports 40 and the vacuum ports 50 are provided at the ends of the cylinders 16 and 52. The supply port 10 and the vacuum port 50 are equipped with collet chucks 10a and 50a for inserting and removing air tubes with one touch.

Switching between vacuum generation and vacuum break is performed by controlling the communication between the first communication passage 12 and the second communication passage 14 by the action of the spool valve 60, similarly to the conventional device. The spool valve 60 is arranged laterally of the supply port 10 with its axial direction parallel to the axial direction of the cylinder 16. The axial direction of the spool valve 60 does not necessarily have to be parallel to the axial direction of the cylinder 16. The first communication channel 12 and the second communication channel 14 are provided so as to extend laterally from the side of the supply port 10 and the cylinder 16, and the supply port 10 and the cylinder 16 and the spool valve 60 are mounted. It communicates with the cylinder part 61.

The spool valve 60 is formed with a small diameter portion 62 at the middle portion in the axial direction. The outer peripheral surface of the small diameter portion 62 and the spool valve 6 are
A space is formed between the inner peripheral surface of the cylinder portion 61 on which 0 slides. Reference numeral 64 denotes an air packing provided around an inclined step portion at the end of the small diameter portion 62. The step portion formed on the inner peripheral surfaces of the air packing 64 and the cylinder portion 61 by the spool valve 60 moving in the axial direction. 66 is formed so as to abut or separate. Spool valve 60
The operation of controlling the communication between the first communication flow path 12 and the second communication flow path 14 by means of moving the spool valve 60 forward and backward in the axial direction to bring the air packing 64 into contact with or separate from the step portion 66. It is due to the operation.

That is, when the spool valve 60 moves forward and the air packing 64 abuts on the step portion 66 on the inner surface of the cylinder portion 61, the inflow of compressed air from the supply port 10 is blocked, and the first communication is performed. The flow path 12 and the second communication flow path 14 are in a blocked state. Further, when the spool valve 60 is retracted and the air packing 64 and the step portion 66 on the inner surface of the cylinder portion 61 are separated from each other, the compressed air sent from the supply port 10 and the cylinder portion 61 are compressed. It is a state in which the first communication channel 12 and the second communication channel 14 are in communication with each other by communicating with the second communication channel 14 via a gap portion with the inner peripheral surface of. 1 shows a state in which the air packing 64 of the spool valve 60 and the step portion 66 are separated (vacuum is generated), and FIG. 2 shows a state in which the air packing 64 of the spool valve 60 is in contact with the step portion 66 (vacuum break). .

The pilot valve 70 has a function of moving the spool valve 60 back and forth between two positions, a forward position and a backward position. In the present embodiment, the pilot valve 70 switches the compressed air acting on both ends of the spool valve 60 to move the spool valve 60 forward and backward. In reality, the spool valve 60
A piston 68 having a diameter larger than that of the spool valve 60 is brought into contact with the front end face of the piston 68, and compressed air acting on the front end face of the piston 68 and the rear end face of the spool valve 60 is switched by the pilot valve 70 to act on the front end face of the piston 68. The spool valve 60 is moved by the difference between the thrust of the compressed air and the thrust of the compressed air that acts on the rear end surface of the spool valve 60.

Reference numeral 72 is an electromagnet, and 74 is an armature driven by the electromagnet 72. When the flow path to the front end face of the piston 68 is opened by the armature 74, the thrust force of the compressed air acting on the front end of the spool valve 60 is generated.
The spool valve 60 retracts (vacuum is generated) over the thrust acting on the rear end, and when the flow passage to the front end face of the piston 68 is closed, the thrust of the compressed air acting on the rear end face of the spool valve 60 is generated. The spool valve 60 moves forward (vacuum breaking state). In this way, the pilot valve 70 controls switching of compressed air, and uses the pressure of compressed air to move the spool valve 60. The method of moving the spool valve 60 back and forth using the pressing force of compressed air is the electromagnet 7
2 has the advantage of not requiring a large power. Of course, the method for moving the spool valve 60 is not limited to this method.

The compressed air introduced into the cylinder 16 from the second connecting flow passage 14 is narrowed by the nozzle 18 and is jetted toward the rear end of the diffuser spool 20 to generate a vacuum. 22 is the nozzle 18 and the diffuser spool 20
The air injection portion is a space between the rear end and the rear end. Both the nozzle 18 and the diffuser spool 20 are cylinders 1.
It is arranged movably in the axial direction within 6. 24 is the nozzle 18
Is a seal member provided around the outer surface of the second communication channel 1
When compressed air is fed from 4, the seal member 24 performs air sealing between the inner peripheral surface of the cylinder 16 and the outer peripheral surface of the nozzle 18, and the inner peripheral portion of the nozzle 18 moves from the inner diameter portion of the nozzle 18 at the moving position where the nozzle 18 moves forward. Compressed air is ejected.

The forward position of the diffuser spool 20 is
The front end side of the diffuser spool 20 (exhaust port 40
The air packing 26 attached to the stepped portion 20c connecting the small diameter portion 20a (on the side) and the large diameter portion 20b on the rear end side of the diffuser spool 20 contacts the stopper stepped portion 16a formed on the inner peripheral surface of the cylinder 16. Regulated by Small-diameter portion 20a on the tip side of the diffuser spool 20
Is provided to form a gap between the outer peripheral surface of the diffuser spool 20 and the inner peripheral surface of the cylinder 16 to form an auxiliary flow path for vacuum breaking.

Reference numeral 28 denotes a spring as an urging means mounted on the outer surface of the small diameter portion 20a of the diffuser spool 20. The spring 28 is arranged so as to spring between a locking projection 16b formed on the inner surface of the cylinder 16 and a projection provided on the outer surface of the diffuser spool 20, and biases the diffuser spool 20 in a direction to always move rearward. To set up. This allows the diffuser spool 2
The diffuser spool 20 will move rearward unless 0 is pushed forward. Diffuser spool 20
The rear end face is in contact with the nozzle 18, and the position when the diffuser spool 20 is retracted is restricted by the position where the rear end face of the nozzle 18 is in contact with the end face of the stopper 19.

The cylinder 16 side and the vacuum port 50 side communicate with each other through a communication passage 45. A communication hole is opened in the outer peripheral surface of the diffuser spool 20 in the vicinity of the vacuum generating portion 22, and the cylinder 1 is connected through the communication hole and the communication flow passage 45.
6 communicates with the vacuum port 50 side. The communication passage 45 is bent from the side of the cylinder 16 and communicates with the cylinder 52 on the vacuum port 50 side. Compressed air is jetted from the nozzle 18 and the jet flow sucks air from the cylinder 52 side. Reference numeral 35 is a silencer element for canceling the noise when compressed air flows through the cylinder 1.
6 is provided on the inner peripheral surface on the tip side. 40a is a cap for attaching and detaching the silencer element 35. Reference numeral 54 is a filter arranged inside the cylinder 52 on the vacuum port 50 side. The filter 54 has a function of protecting dirty air from entering the vacuum generator main body when sucking air.

The vacuum generator according to the present embodiment carries out the suction and release operations of the work by the following actions. FIG. 1 shows a vacuum generation state in which a work is adsorbed and supported by the vacuum port 50 side. The vacuum generation state means that the spool valve 60 is moved to the retracted position by the pilot valve 70 as described above,
The first communication channel 12 and the second communication channel 14 are in communication with each other, and the compressed air from the supply port 10 is supplied to the nozzle 18 side. When compressed air is supplied to the nozzle 18, the nozzle 18 and the diffuser spool 20 are pushed forward by the air pressure, and the air packing 26 of the diffuser spool 20 contacts the stopper step 16a of the cylinder 16. This diffuser spool 20 and nozzle 1
The operation of pushing 8 forward is performed by the diffuser spool 2
It is done against the urging force of the spring 28 mounted on the outer surface of the spring 0.
It must be set to exceed the urging force of 8.

When the diffuser spool 20 is moved to the forward position and the air packing 26 is in contact with the stopper step 16a, the air flow flows only through the inner diameter portion of the diffuser spool 20, and the normal nozzle 18 and the diffuser spool 20 generate a vacuum. The action is played. That is, the high-speed jet flow from the nozzle 18 sucks air from the vacuum port 50 side through the communication passage 45, and the work can be sucked by air.

FIG. 2 shows a vacuum port 5 for breaking a workpiece by breaking the vacuum.
The operation state of separating from the 0 side is shown. Vacuum break first,
The spool valve 60 is moved from the retracted position to the advanced position by the control of the pilot valve 70, and the air packing 64 of the spool valve 60 is brought into contact with the step portion 66. As a result, the first communication channel 12 and the second communication channel 14 are shut off, and the compressed air supplied from the supply port 10 is discharged from the nozzle 1
8 and the diffuser spool 20 are not fed into the cylinder 16 in which they are mounted. When the pressing force of the compressed air stops acting on the nozzle 18 and the diffuser spool 20, the urging force of the spring 28 mounted between the diffuser spool 20 and the locking projection 16b on the inner surface of the cylinder 16 pushes the diffuser spool 20 to the retracted position. Move and move. 2 shows the diffuser spool 2
0 is in the state of moving to the retracted position.

The fact that the diffuser spool 20 moves to the retracted position means that the air packing 26 provided on the diffuser spool 20 and the stopper step 16a provided on the inner surface of the cylinder 16 are separated from each other, and the diffuser spool 2
It means that the small diameter portion 20a of 0 and the inner surface of the cylinder 16 communicate with each other as the auxiliary flow passage 30. That is, when the compressed air from the supply port 10 ceases to act inside the cylinder 16, atmospheric air flows from the exhaust port 40 into the vacuum circuit where air is being sucked, and the vacuum is broken, so that the vacuum port 50.
The work that was adsorbed by the air is released. In the vacuum generator of the present embodiment, the operation in which the atmosphere flows into the vacuum circuit to break the vacuum causes the flow path of the diffuser spool 20 to be broken from the inner diameter portion of the diffuser spool 20 via the communication flow path 45 and the diffuser spool 20. Since it is made by both of the flow channels that are destroyed via the auxiliary flow channel 30 that passes through the outer peripheral surface side,
The rise of the vacuum break becomes faster, and it becomes possible to break the vacuum instantly.

In the conventional vacuum generator using the diffuser spool 20, only the vacuum break through the inner diameter portion of the diffuser spool 20 can be performed, whereas in the vacuum generator of the present embodiment, the outer surface side of the diffuser spool 20. By using the auxiliary flow path 30 that flows through, a faster vacuum break is possible. Since the operation of moving the diffuser spool 20 depends on the urging force of the spring 28, there is an advantage that the diffuser spool 20 can be moved instantaneously and the structure can be simplified. The silencer element 35 and the filter 52 use the flowing air at the time of breaking the vacuum as clean air to prevent the work from being contaminated by the air operation.

When vacuum suction is performed after breaking the vacuum,
The spool valve 60 may be moved from the forward position of FIG. 2 to the backward position of FIG. 1 by the control of the pilot valve 70 so that the first communication passage 12 and the second communication passage 14 are communicated with each other. Since the first communication flow path 12 and the second communication flow path 14 communicate with each other, both the nozzle 18 and the diffuser spool 20 move to the forward position against the biasing force of the spring 28, and the auxiliary flow path 30 is formed. It is closed and a vacuum is generated in which compressed air is discharged through the inner diameter of the diffuser spool 20. In this manner, the vacuum generation state and the vacuum break state are appropriately generated, and the work is sucked and released.

FIG. 3 shows an air circuit diagram at the time of breaking the vacuum of the vacuum generator of the embodiment shown in FIGS. In the figure, the diffuser spool 20 moves to the vacuum breaking position during vacuum breaking, and the circuit is broken by the vacuum generating unit 100 and the circuit of another system by the diffuser spool 20. In the above embodiment, the introduction of the air through the auxiliary flow path 30 at the time of breaking the vacuum is common to the exhaust port 40 used when the vacuum is generated. An example provided in a system different from 40 is shown. It is not always necessary to introduce the atmosphere from the exhaust port 40 when introducing the atmosphere via the diffuser spool 20 at the time of vacuum breaking, and it is also possible to introduce the atmosphere from the atmosphere introducing port of another system to break the vacuum. .

For example, the cylinder 1 on the exhaust port 40 side
6 is provided with an air introduction port for breaking the vacuum, and the filter 52
It is also possible to introduce the atmosphere from this atmosphere introduction port via a. By taking in the atmosphere through the filter 52a when taking in the air and breaking the vacuum of the vacuum circuit, the dirty atmosphere is prevented from entering the main body of the vacuum generator, and the function of the vacuum generator is not deteriorated. Can be protected.

In the above embodiment, the vacuum breaking operation has been described by introducing the atmosphere from the exhaust port 40 to break the air (passive method), but compressed air is supplied to the vacuum circuit as shown in FIG. It is also possible to apply it to a device for introducing and breaking the vacuum.

[0032]

As described above, according to the vacuum generator of the present invention, the diffuser spool is movably provided in the cylinder in the axial direction, so that the diffuser spool moves to the vacuum breaking position at the time of vacuum breaking and the auxiliary flow is generated. Since it is possible to introduce the atmosphere into the vacuum circuit via the passage, it is possible to shorten the rise time of the vacuum break,
It is possible to break the vacuum at a higher speed than in the conventional case, and it is possible to perform the suction transfer operation of the work at a higher speed and efficiently, and the like.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a configuration (vacuum generation state) of an embodiment of a vacuum generator according to the present invention.

FIG. 2 is a cross-sectional view showing a configuration (state when vacuum is broken) of an embodiment of a vacuum generator according to the present invention.

FIG. 3 is an explanatory diagram showing an air circuit of an embodiment of a vacuum generator.

FIG. 4 is an explanatory view showing an air circuit of another embodiment of the vacuum generator.

FIG. 5 is a cross-sectional view showing a conventional configuration example of a vacuum generator.

FIG. 6 is a cross-sectional view showing another conventional configuration example of the vacuum generator.

[Explanation of symbols]

10 supply ports 12 First communication channel 14 Second communication channel 16 cylinders 16a Stopper step 16b locking protrusion 18 nozzles 20 diffuser spool 20a small diameter part 22 Vacuum generator 24 Seal member 26 Air packing 28 springs 30 Auxiliary flow path 35 Silencer element 40 exhaust port 45 communication channel 50 vacuum port 52 cylinders 60 spool valve 64 air packing 66 Step 68 pistons 70 Pilot valve

─────────────────────────────────────────────────── ─── Continuation of front page (56) References JP-A-6-264900 (JP, A) JP-A-9-317699 (JP, A) JP-B-57-41600 (JP, B2) (58) Field (Int.Cl. ⁷ , DB name) B25J 15/06 F04F 5/00

Claims (5)

(57) [Claims] 1. A control unit for controlling ON / OFF of air supply of compressed air supplied from a supply port, and a compressed air supplied to the cylinder when the air supply is turned on to inject from a nozzle to an exhaust port via a diffuser spool. In a vacuum generator comprising a vacuum generating section for generating a vacuum by discharging the diffuser from the vacuum generator and a vacuum port communicating with the vacuum generating section, the diffuser spool is provided movably in the axial direction in the cylinder, and A gap is provided between the outer peripheral surface and the inner surface of the cylinder, which serves as an auxiliary flow path for vacuum break at the time of vacuum break. When the air supply is turned on, the diffuser spool moves to the forward position due to the pressing force of the compressed air. The air gap is closed and air is sucked from the vacuum port. When the air supply is turned off, the diffuser spool is moved to the retracted position. A vacuum generator characterized in that the vacuum generator can be moved and passed through the exhaust port, the auxiliary flow path, and the inner diameter portion of the diffuser spool so as to be capable of breaking vacuum. 2. The diffuser spool is biased in a direction in which the diffuser spool is moved from the forward movement position toward the backward movement position, and when the air is turned on, the diffuser spool is pushed against the biasing force by the pressing force of compressed air. 2. The vacuum generator according to claim 1, further comprising a biasing unit that moves the diffuser spool to the retracted position by a biasing force when the air is turned off when the air is turned off. 3. The outer peripheral surface of the diffuser spool,
At the forward position, the auxiliary flow path is closed by contacting a stopper step formed on the inner peripheral surface of the cylinder, and at the retracted position, the auxiliary step is separated from the stopper step formed on the inner peripheral surface of the cylinder. 3. The vacuum generator according to claim 1, further comprising an air packing that connects a flow path to the vacuum port. 4. The atmosphere introducing port equipped with a filter, which is separate from the exhaust port, is provided in communication with the auxiliary flow path of the diffuser spool. Vacuum generator. 5. A pilot valve for switching compressed air supplied from the supply port, the control section moving a spool valve forward and backward by a switching operation of the compressed air by the pilot valve, and the supply valve depending on a moving position of the spool valve. ON-OFF air supply from port to cylinder
The vacuum generator according to claim 1, 2, 3 or 4, wherein the vacuum generator is provided for the purpose.