CN115076167A

CN115076167A - Factory air system

Info

Publication number: CN115076167A
Application number: CN202210213454.1A
Authority: CN
Inventors: 都築温实
Original assignee: Toyota Motor Corp
Current assignee: Toyota Motor Corp
Priority date: 2021-03-16
Filing date: 2022-03-04
Publication date: 2022-09-20
Also published as: JP2022142040A

Abstract

The invention provides a plant air system, which increases the flow rate of air supplied to a load. The plant air system includes: a first cylinder; a second cylinder; a first piston which is housed in the first cylinder and divides the interior of the first cylinder into a first chamber and a second chamber into which external air can flow via a first check valve; a second piston which is housed in the second cylinder and divides the interior of the second cylinder into a third chamber and a fourth chamber into which external air can flow via a second check valve; a piston rod inserted into through holes provided in the second chamber and the fourth chamber, respectively, and having a first piston provided at one end portion and a second piston provided at the other end portion; and a switching valve that, when the air supply source is communicated with the first chamber, causes the second chamber and the third chamber to communicate with each other, and discharges air in the third chamber into the second chamber, thereby reducing pressure of the air in the third chamber and sending the air from the second chamber to the air outlet together with the air in the second chamber.

Description

Factory air system

Technical Field

The present disclosure relates to plant air systems.

Background

Regarding a plant air system, patent document 1 discloses a supercharging device that supercharges a fluid. In this supercharging device, pistons disposed in the first drive chamber, the supercharging chamber, and the second drive chamber are connected by one piston rod. Each driving chamber is divided into an inner pressurizing chamber and an outer pressurizing chamber by an inner piston. In this supercharging apparatus, the exhaust gas from the inner compression chamber is supplied to the outer compression chamber through the return flow path, whereby the piston in the drive chamber is displaced toward the supercharging chamber side, and the supercharging chamber is supercharged.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2018-84270

Disclosure of Invention

Problems to be solved by the invention

In the above document, the air can be pressurized. In contrast, in a plant air system, air pressure reduction may be performed. In a plant air system that performs such air pressure reduction, a technique that can increase the flow rate of air to be supplied to a load is desired in order to improve the air supply efficiency.

Means for solving the problems

The present disclosure can be implemented in the following forms.

(1) According to a first aspect of the present disclosure, there is provided a plant air system that decompresses compressed air supplied from an air supply source and supplies the decompressed air to a load. This factory air system includes: a first cylinder; a second cylinder; a first piston which is housed in the first cylinder and which divides the interior of the first cylinder into a first chamber and a second chamber into which external air can flow via a first check valve; a second piston which is housed in the second cylinder and divides the interior of the second cylinder into a third chamber and a fourth chamber into which external air can flow via a second check valve; a piston rod having the first piston at one end and the second piston at the other end and inserted into through holes provided in the second chamber and the fourth chamber, respectively; an air outlet that communicates with the second chamber and the fourth chamber and supplies the load with air sent from the second chamber or the fourth chamber; and a switching valve connected to the air supply source, the first chamber, the second chamber, the third chamber, and the fourth chamber, and capable of switching a communication state among the air supply source, the first chamber, the second chamber, the third chamber, and the fourth chamber, wherein when the air supply source is communicated with the first chamber, the switching valve causes the second chamber and the third chamber to communicate with each other, and discharges air in the third chamber into the second chamber, thereby reducing pressure of air in the third chamber and sending the air in the second chamber together with air in the second chamber from the second chamber to the air outlet.

In this case, when the compressed air is supplied to the first chamber, the air in the third chamber is discharged into the second chamber and is sent to the air outlet together with the air in the second chamber by causing the second chamber and the third chamber to communicate with each other, so that the flow rate of the depressurized air supplied to the load can be increased.

(2) In the above aspect, when the air supply source is made to communicate with the third chamber, the switching valve may communicate the first chamber with the fourth chamber to discharge the air in the first chamber into the fourth chamber, thereby reducing the pressure of the air in the first chamber and sending the air from the fourth chamber to the air outlet together with the air in the fourth chamber. In this case, when the compressed air is supplied to the third chamber, the first chamber and the fourth chamber are communicated with each other, whereby the air in the first chamber is discharged into the fourth chamber and is sent to the air outlet together with the air in the fourth chamber.

(3) In the above aspect, the switching valve and the first chamber may be connected via a first speed control valve that generates a control flow from the switching valve to the first chamber and a free flow from the first chamber to the switching valve. In this manner, when the air supply source is communicated with the first chamber, the first piston can be stably moved. In addition, when the first chamber and the fourth chamber are made to communicate with each other, air can be smoothly discharged from the first chamber to the fourth chamber.

(4) In the above aspect, the switching valve and the third chamber may be connected via a second speed control valve that generates a control flow from the switching valve to the third chamber and a free flow from the third chamber to the switching valve. In this manner, when the air supply source is communicated with the third chamber, the second piston can be stably moved. In addition, when the second chamber and the third chamber are communicated with each other, air can be smoothly discharged from the third chamber to the second chamber.

(5) In the above aspect, the valve may include a mechanical valve that detects a position of the piston rod, and the switching valve may switch the communication state based on pilot air output from the mechanical valve. In this manner, the plant air system can be operated by the pressure of the air without using electricity.

The present disclosure can be implemented in various forms other than the above-described form as a plant air system, such as a pressure reducing device and a pressure reducing method.

Drawings

Fig. 1 is an explanatory diagram showing a schematic configuration of a plant air system.

Fig. 2 is an explanatory diagram showing a schematic configuration of a plant air system.

Fig. 3 is an explanatory diagram showing a schematic configuration of a plant air system.

Fig. 4 is an explanatory diagram showing a first application example of the plant air system.

Fig. 5 is an explanatory diagram showing a second application example of the plant air system.

Detailed Description

A. The first embodiment:

fig. 1 to 3 are explanatory views showing a schematic configuration of a plant air system 100 as an embodiment of the present disclosure. Reference is primarily made to fig. 1 below. The plant air system 100 is a system that supplies compressed air to a load by reducing the pressure of the compressed air supplied from an air supply source 105 such as a compressor. The plant air system 100 may also be referred to as a pressure reduction device. The plant air system 100 includes a first cylinder 110, a second cylinder 120, a first piston 131, a second piston 132, a piston rod 150, an air outlet 160, and a switching valve 170.

The first cylinder block 110 is a hollow cylindrical member having a first upper surface 118 and a first bottom surface 119. The second cylinder 120 is a hollow cylindrical member having a second upper surface 128 and a second bottom surface 129. The first cylinder 110 accommodates a first piston 131, and the second cylinder 120 accommodates a second piston 132. The first cylinder block 110 and the second cylinder block 120 are disposed such that the first bottom surface 119 of the first cylinder block 110 opposes the second bottom surface 129 of the second cylinder block 120.

The first piston 131 housed in the first cylinder 110 divides the interior of the first cylinder 110 into the first chamber 111 and the second chamber 112. The outside air, i.e., the atmospheric air, can flow into the second chamber 112 through the first check valve 181. The first check valve 181 is configured to allow air to flow into the second chamber 112 from the outside and to suppress air from flowing out of the second chamber 112 to the outside.

The second piston 132 housed in the second cylinder 120 divides the interior of the second cylinder 120 into the third chamber 123 and the fourth chamber 124. The outside air, i.e., the atmospheric air, can flow into the fourth chamber 124 via the second check valve 182. The second check valve 182 is configured to allow inflow of air from the outside into the fourth chamber 124 and to suppress outflow of air from the fourth chamber 124 to the outside.

The piston rod 150 is inserted into through holes provided in the second chamber 112 of the first cylinder 110 and the fourth chamber 124 of the second cylinder 120, respectively. More specifically, the piston rod 150 is inserted into a through hole provided at the center of the first bottom surface 119 constituting a part of the second chamber 112 of the first cylinder 110 and a through hole provided at the center of the second bottom surface 129 constituting a part of the third chamber 123 of the second cylinder 120. The piston rod 150 has a first piston 131 at one end and a second piston 132 at the other end. A portion of the piston rod 150 located between the first cylinder 110 and the second cylinder 120 is provided with an enlarged diameter portion 151 having a larger diameter than other portions.

A mechanical valve for detecting the position of the piston rod 150 is disposed between the first cylinder 110 and the second cylinder 120. In the present embodiment, the first mechanical valve 101 and the second mechanical valve 102 are arranged to detect the positions of the first piston 131 and the second piston 132 connected to the piston rod 150 separately. The first mechanical valve 101 is disposed between the first cylinder 110 and the second mechanical valve 102, and the second mechanical valve 102 is disposed between the first mechanical valve 101 and the second cylinder 120. The mechanical valve may also be referred to as a limit valve.

In the present embodiment, when the first piston 131 is closest to the first upper surface 118 of the first cylinder 110 and the second piston 132 is closest to the second bottom surface 129 of the second cylinder 120, that is, when the volumes of the first chamber 111 and the fourth chamber 124 are minimized, the diameter-enlarged portion 151 of the piston rod 150 contacts the first mechanical valve 101. When the diameter-enlarged part 151 comes into contact with the first mechanical valve 101, the first mechanical valve 101 outputs compressed air as pilot air to a switching valve 170, which will be described later, through a flow path, not shown. The pilot air output from the first mechanical valve 101 is also referred to as first pilot air hereinafter. The compressed air for the first pilot air is supplied from the air supply source 105.

In the present embodiment, when the first piston 131 is closest to the first bottom surface 119 of the first cylinder 110 and the second piston 132 is closest to the second top surface 128 of the second cylinder 120, that is, when the volumes of the second chamber 112 and the third chamber 123 are minimized, the diameter-enlarged portion 151 of the piston rod 150 contacts the second mechanical valve 102. When the diameter-enlarged portion 151 comes into contact with the second mechanical valve 102, the second mechanical valve 102 outputs compressed air as pilot air to a switching valve 170, which will be described later, through a flow path, not shown. The pilot air output from the second mechanical valve 102 is also referred to as second pilot air hereinafter. The compressed air for the second pilot air is supplied from the air supply source 105.

The air outlet 160 communicates with the second chamber 112 of the first cylinder 110 and the fourth chamber 124 of the second cylinder 120. The air outlet 160 supplies the air supplied from the second chamber 112 or the fourth chamber 124 to the load. The air outlet 160 is connected to a junction between a first outlet passage 161 communicating with the second chamber 112 and a second outlet passage 162 communicating with the fourth chamber 124. The third check valve 183 is disposed in the first outlet passage 161, and the fourth check valve 184 is disposed in the second outlet passage 162. The third check valve 183 allows the outflow of air from the second chamber 112 to the air outlet 160 and inhibits the inflow of air from the air outlet 160 and the fourth chamber 124 to the second chamber 112. The fourth check valve 184 allows air to flow out from the fourth chamber 124 to the air outlet 160 and inhibits air from flowing in from the air outlet 160 and the second chamber 112 to the fourth chamber 124. In the present embodiment, the first check valve 181 communicates with the second chamber 112 via the first outlet passage 161. The second check valve 182 communicates with the fourth chamber 124 via the second outlet flow path 162. However, the first check valve 181 may be directly connected to the second chamber 112 without passing through the first outlet flow path 161, and the second check valve 182 may be directly connected to the fourth chamber 124 without passing through the second outlet flow path 162.

The switching valve 170 is connected to the air supply source 105, the first chamber 111, the second chamber 112, the third chamber 123, and the fourth chamber 124. Specifically, the first chamber 111 and the switching valve 170 are connected by a first flow path 171. The second chamber 112 is connected to the switching valve 170 via a second flow path 172. The third chamber 123 and the switching valve 170 are connected by a third flow path 173. The fourth chamber 124 and the switching valve 170 are connected by a fourth flow path 174.

The switching valve 170 switches the communication state of the air supply source 105, the first chamber 111, the second chamber 112, the third chamber 123, and the fourth chamber 124 according to the pilot air output from the

mechanical valves

101 and 102. The switching valve 170 of the present embodiment is configured as a direction switching valve having a valve body therein. More specifically, in the present embodiment, the switching valve 170 is configured by a two-port air-operated valve that has five ports and is capable of switching the position of the valve body to two positions.

The first flow path 171 is provided with a first speed control valve 191. That is, the switching valve 170 and the first chamber 111 are connected via the first speed control valve 191. The first speed control valve 191 has a structure in which a check valve and a throttle valve are connected in parallel. The first speed control valve 191 is configured to generate a control flow from the switching valve 170 to the first chamber 111 and a free flow from the first chamber 111 to the switching valve 170 by the check valve and the throttle valve.

The third flow path 173 is provided with a second speed control valve 192. That is, the switching valve 170 and the third chamber 123 are connected via the second speed control valve 192. The second speed control valve 192 has a structure in which a check valve and a throttle valve are connected in parallel. The second speed control valve 192 is configured to generate a control flow from the switching valve 170 to the third chamber 123 and a free flow from the third chamber 123 to the switching valve 170 by the check valve and the throttle valve.

The throttle opening degrees of the throttle valves included in the first speed control valve 191 and the second speed control valve 192 are set by simulation or experiment so that the pressure reducing operation by the plant air system 100 is smoothly performed. In addition, the speed control valve is also referred to as a speed controller.

Fig. 1 shows a state where the switching valve 170 is displaced to the first position. In the first position, the switching valve 170 communicates the air supply source 105 with the fourth chamber 124 through the third flow path 173, and communicates the first chamber 111 with the fourth chamber 124 through the first flow path 171 and the fourth flow path 174. In addition, at the first position, the switching valve 170 shuts off the second flow path 172 so that the second chamber 112 does not communicate with the air supply source 105, the first chamber 111, the third chamber 123, and the fourth chamber 124.

Fig. 2 shows a state in which the switching valve 170 is displaced to the second position. At the second position, the switching valve 170 communicates the air supply source 105 with the first chamber 111 through the first flow path 171, and communicates the second chamber 112 with the third chamber 123 through the second flow path 172 and the third flow path 173. In addition, at the second position, the switching valve 170 shuts off the fourth flow path 174 so that the fourth chamber 124 does not communicate with the air supply source 105, the first chamber 111, the second chamber 112, and the third chamber 123.

In the present embodiment, the switching valve 170 changes its position from the first position to the second position when it receives the first pilot air from the first mechanical valve 101. When receiving the second pilot air delivery from the second mechanical valve 102, the switching valve 170 changes its position from the second position to the first position. In this way, the switching valve 170 is alternately shifted to the first position and the second position, whereby the decompression of the compressed air is continuously performed in the plant air system 100.

The operation of the plant air system 100 will be described with reference to fig. 1 to 3. Fig. 1 shows a state in which the first piston 131 in the first cylinder 110 reaches the end portion on the first upper surface 118 side and the second piston 132 in the second cylinder 120 reaches the end portion on the second bottom surface 129 side in a state in which the switching valve 170 is displaced to the first position. Hereinafter, for convenience of description, a direction from the first bottom surface 119 toward the first upper surface 118 of the first cylinder block 110 is referred to as an "L direction", and an opposite direction thereof is referred to as an "R direction". The L direction and the R direction are directions in which the first piston 131 and the second piston 132 move, and are directions along the axial direction of the piston rod 150.

In the state shown in fig. 1, the third chamber 123 of the second cylinder 120 is filled with compressed air supplied from the air supply source 105 through the switching valve 170 and the third flow path 173. The second chamber 112 of the first cylinder 110 is filled with air sucked from the outside through the first check valve 181.

As shown in fig. 1, when the first piston 131 and the second piston 132 reach the end in the L direction, the first mechanical valve 101 comes into contact with the enlarged diameter portion 151 of the piston rod 150, and the first pilot air is output from the first mechanical valve 101 to the switching valve 170. The switching valve 170 is shifted from the first position shown in fig. 1 to the second position shown in fig. 2 by the input of the first pilot air.

Fig. 2 shows a state in which the first piston 131 in the first cylinder 110 is moved in the R direction and the second piston 132 in the second cylinder 120 is moved in the R direction by the displacement of the switching valve 170 to the second position.

When the switching valve 170 is switched from the first position to the second position shown in fig. 2, the compressed air is supplied from the air supply source 105 to the first chamber 111 of the first cylinder 110 through the first flow path 171 and the first speed control valve 191. Then, the first piston 131 moves in the R direction by a thrust force corresponding to the difference in the pressure receiving area of the front and back sides of the first piston 131, and along with this, the air accumulated in the second chamber 112 is sent to the air outlet 160 through the first outlet flow path 161 and the third check valve 183. When the first piston 131 moves in the R direction, the second piston 132 is also pushed by the piston rod 150 and moves in the R direction in the second cylinder 120. Then, the external air is sucked into the fourth chamber 124 of the second cylinder 120 through the second check valve 182, and the compressed air accumulated in the third chamber 123 is delivered to the second chamber 112 through the third flow path 173 and the second flow path 172 while being decompressed. The air delivered to the second chamber 112 is delivered to the air outlet 160 through the first outlet flow path 161 and the third check valve 183 together with the air accumulated in the second chamber 112, and is supplied to the load as depressurized air.

Fig. 3 shows a state where the first piston 131 and the second piston 132 reach the end in the R direction. In this state, all of the air in the second chamber 112 and the compressed air in the third chamber 123 are sent to the air outlet 160 and supplied to the load. The first chamber 111 is filled with compressed air supplied from the air supply source 105, and the fourth chamber 124 is filled with air drawn from the outside.

As shown in fig. 3, when the first piston 131 and the second piston 132 reach the end in the R direction, the second mechanical valve 102 comes into contact with the enlarged diameter portion 151 of the piston rod 150, and the second pilot air is output from the second mechanical valve 102 to the switching valve 170. The switching valve 170 is shifted from the second position shown in fig. 3 to the first position shown in fig. 1 by the input of the second pilot air. Then, compressed air is supplied to the third chamber 123, and the second piston 132 moves in the L direction by a thrust force corresponding to the difference in the pressure receiving area of the front and back of the second piston 132, and along with this, the first piston 131 also moves in the L direction. Then, the external air is sucked into the second chamber 112 of the first cylinder 110 through the first check valve 181, and the compressed air stored in the first chamber 111 is delivered to the fourth chamber 124 while being decompressed through the first flow path 171 and the fourth flow path 174. The air sent to the fourth chamber 124 is sent to the air outlet 160 through the second outlet flow path 162 and the fourth check valve 184 together with the air accumulated in the fourth chamber 124, and is supplied to the load as depressurized air.

In the present embodiment, by repeating the above-described operation, the plant air system 100 supplies the load with the reduced pressure air.

According to the plant air system 100 of the present embodiment described above, when compressed air is supplied to the first chamber 111 of the first cylinder 110 and the first piston 131 and the second piston 132 are moved in the R direction, the second chamber 112 and the third chamber 123 are communicated with each other, whereby air existing in the third chamber 123 is discharged to the second chamber 112 of the first cylinder 110 without being discharged to the outside, and is supplied from the second chamber 112 to a load together with air accumulated in the second chamber 112. Therefore, the flow rate of the depressurized air supplied to the load can be increased. In the present embodiment, when compressed air is supplied to the third chamber 123 of the second cylinder 120 and the second piston 132 and the first piston 131 are moved in the L direction, the first chamber 111 and the fourth chamber 124 are communicated with each other, whereby air existing in the first chamber 111 of the first cylinder 110 is discharged to the fourth chamber 124 of the second cylinder 120 without being discharged to the outside, and is supplied from the fourth chamber 124 to the load together with air accumulated in the fourth chamber 124. Therefore, the flow rate of the depressurized air supplied to the load can be further increased. As described above, in the present embodiment, the flow rate of the depressurized air can be increased in both the R-direction operation and the L-direction operation of the first piston 131 and the second piston 132.

In the present embodiment, since the switching valve 170 is connected to the first chamber 111 of the first cylinder 110 via the first speed control valve 191, when the air supply source 105 is communicated with the first chamber 111 and compressed air is supplied from the air supply source 105 to the first chamber 111, a control flow of the compressed air can be generated. Therefore, the first piston 131 can be stably moved. Further, when the first chamber 111 and the fourth chamber 124 are communicated and the compressed air is discharged from the first chamber 111 to the fourth chamber 124, a free flow of the compressed air can be generated, and therefore, the air can be smoothly discharged from the first chamber 111 to the fourth chamber 124. In the present embodiment, since the switching valve 170 and the third chamber 123 of the second cylinder 120 are connected via the second speed control valve 192, when the air supply source 105 and the third chamber 123 are communicated and compressed air is supplied from the air supply source 105 to the third chamber 123, a control flow of the compressed air can be generated. Therefore, the second piston 132 can be stably moved. Further, when the second chamber 112 and the third chamber 123 are communicated and the compressed air is discharged from the third chamber 123 to the second chamber 112, a free flow of the compressed air can be generated, and therefore, the air can be smoothly discharged from the third chamber 123 to the second chamber 112. As described above, in the present embodiment, the first speed control valve 191 and the second speed control valve 192 are provided in the plant air system 100, whereby the plant air system 100 can perform a stable pressure reduction operation.

In the present embodiment, the switching valve 170 switches the communication state of each flow path by the pilot air output from the

mechanical valves

101 and 102, and therefore the plant air system 100 can be operated by only the compressed air without using electricity. Therefore, the energy saving performance of the plant air system 100 can be improved.

In the present embodiment, the cylinder to which the compressed air is supplied can be referred to as a driving cylinder. The cylinder that supplies the reduced pressure air to the load can be referred to as a pump cylinder. In the present embodiment, the first cylinder 110 and the second cylinder 120 alternately operate as a driving cylinder and a pump cylinder, respectively, by the switching valve 170 being returned to the first position and the second position.

B. Application example:

fig. 4 is an explanatory diagram showing a first application example of the plant air system 100, and in the first application example shown in fig. 4, a machining line 20 having an NC device or the like is connected in parallel to a prime mover compressor 10 as an air supply source for generating compressed air of 400 kPa. Each machining line 20 is provided with a pressure reducing valve 30 for reducing the pressure of compressed air from 400kPa to 300 kPa. The reduced pressure air of 300kPa is used for driving various cylinders 40 provided in the machining line. The machining line 20 is provided with the plant air system 100 of the above embodiment in parallel with the pressure reducing valve 30, and the plant air system 100 reduces the pressure of the compressed air from 400kPa to about 150 kPa. This 150kPa reduced pressure air is used for air blowing of oil used in the NC apparatus or air purging of the main shaft, for example.

As described above, the plant air system 100 can increase the flow rate of the depressurized air supplied to the load. Therefore, in the first application example shown in fig. 4, 166Nm is supplied to the plant air system 100 while the inner diameters of the first cylinder 110 and the second cylinder 120 of the plant air system 100 are set to 300mm and the stroke length is set to 400mm ³ When air is introduced, the pressure can be reducedTo 200Nm ³ And/(h · stage) left and right. Therefore, for example, the air supply efficiency can be improved by at least about 17% as compared with the pressure reduction using a relief type pressure reducing valve in which the air flow rate is not increased.

Fig. 5 is an explanatory diagram showing a second application example of the plant air system 100 described above. In a second application example shown in fig. 5, a prime mover compressor 10 generating compressed air at 600kPa is prepared in association with an assembly line 50 where the required pressure is high. In the assembly line 50, various components are mounted on, for example, an automobile. The plant air system 100 according to the above-described embodiment is connected to the motive power compressor 10 in parallel with the assembly line 50. A plurality of machining lines 20 are connected in parallel to the plant air system 100. In each machining line 20, the depressurized air depressurized by the plant air system 100 is supplied to various cylinders 40, and the air further depressurized by the pressure-reducing valve 30 is used for air blowing or air purging. According to the second application example, the air used in each machining line 20 can be collectively decompressed in the plant air system 100, and therefore each machining line 20 can be operated efficiently.

The pressure values in the first application example and the second application example are examples, and may be set to various pressure values depending on plant equipment. The plant air system 100 according to the above embodiment is not limited to the first application example and the second application example, and can be incorporated into various plant devices.

C. Other embodiments are as follows:

(C-1) in the above embodiment, the air-operated valve is used as the switching valve 170, but an electromagnetic valve may be used. In the above embodiment, the position of the piston is detected by the mechanical valve, but the detection may be performed by an optical or electrical switch.

(C-2) in the above embodiment, the first speed control valve 191 is connected to the first chamber 111 of the first cylinder 110, and the second speed control valve 192 is connected to the third chamber 123 of the second cylinder 120. On the other hand, the first speed control valve 191 and the second speed control valve 192 may be omitted, or either one may be omitted.

(C-3) in the above embodiment, the plant air system 100 is controlled using two

mechanical valves

101, 102 and one switching valve 170. In contrast, the mechanical valve and the switching valve may be configured arbitrarily, and are not limited to the configurations of the above embodiments. For example, a plant air system may also be constructed using a mechanical valve and a single-gang directional control valve with a spring. Further, the plant air system may be configured not to reduce the pressure by both the movement of the piston in the L direction and the movement of the piston in the R direction, but to reduce the pressure when the piston moves in either direction.

The present disclosure is not limited to the above-described embodiments, and can be implemented in various configurations without departing from the scope of the present disclosure. For example, in order to solve part or all of the above-described problems or to achieve part or all of the above-described effects, technical features in embodiments corresponding to technical features in the respective embodiments described in the section of the summary of the invention may be appropriately replaced or combined. In addition, if the technical feature is not described as a necessary technical feature in the present specification, it may be appropriately deleted.

Description of the reference symbols

10 prime mover compressor, 20 machining line, 30 pressure reducing valve, 50 assembly line, 100 plant air system, 101 first machine valve, 102 second machine valve, 105 air supply source, 110 first cylinder, 111 first chamber, 112 second chamber, 118 first upper surface, 119 first bottom surface, 120 second cylinder, 123 third chamber, 124 fourth chamber, 128 second upper surface, 129 second bottom surface, 131 first piston, 132 second piston, 150 piston rod, 151 expanding portion, 160 air outlet, 161 first outlet flow path, 162 second outlet flow path, 170 switching valve, 171 first flow path, 172 second flow path, 173 third flow path, 174 fourth flow path, 181 first check valve, 182 second check valve, 183 third check valve, 184 fourth check valve, 191 first speed control valve, 192 … second speed control valve.

Claims

1. A plant air system that decompresses compressed air supplied from an air supply source and supplies the decompressed air to a load, comprising:

a first cylinder;

a second cylinder;

a first piston which is housed in the first cylinder and which divides the interior of the first cylinder into a first chamber and a second chamber into which external air can flow via a first check valve;

a second piston which is housed in the second cylinder and divides the interior of the second cylinder into a third chamber and a fourth chamber into which external air can flow via a second check valve;

a piston rod having the first piston at one end and the second piston at the other end, the piston rod being inserted into through holes provided in the second chamber and the fourth chamber, respectively;

an air outlet that communicates with the second chamber and the fourth chamber and supplies the load with air sent from the second chamber or the fourth chamber; and

a switching valve connected to the air supply source, the first chamber, the second chamber, the third chamber, and the fourth chamber, and capable of switching a communication state among the air supply source, the first chamber, the second chamber, the third chamber, and the fourth chamber,

in the case where the air supply source is caused to communicate with the first chamber, the switching valve causes the second chamber and the third chamber to communicate with each other, thereby discharging the air in the third chamber into the second chamber, thereby depressurizing the air in the third chamber and transporting the air from the second chamber to the air outlet together with the air in the second chamber.

2. The plant air system of claim 1,

in a case where the air supply source is caused to communicate with the third chamber, the switching valve discharges the air in the first chamber into the fourth chamber by causing the first chamber and the fourth chamber to communicate, thereby decompressing the air in the first chamber and conveying the air from the fourth chamber to the air outlet together with the air in the fourth chamber.

3. The plant air system of claim 1 or 2,

the switching valve and the first chamber are connected via a first speed control valve that generates a control flow from the switching valve to the first chamber and a free flow from the first chamber to the switching valve.

4. The plant air system of any of claims 1 to 3,

the switching valve and the third chamber are connected via a second speed control valve that generates a control flow from the switching valve to the third chamber and a free flow from the third chamber to the switching valve.

5. The plant air system of any of claims 1-4,

the plant air system comprises a mechanical valve detecting the position of the piston rod,

the switching valve switches the communication state in accordance with pilot air output from the mechanical valve.