阅读说明：本技术 流体流路切换装置 (Fluid flow path switching device ) 是由 伊藤新治 林浓男 于 2021-05-24 设计创作，主要内容包括：提供一种能够判断流体泄漏为内部泄漏还是外部泄漏的流体流路切换装置。流体流路切换装置具备：切换阀、供给流路、排出流路、供给侧流量传感器、排出侧流量传感器、压力传感器以及泄漏判断部。所述泄漏判断部执行判断有无内部泄漏的内部泄漏判断处理以及判断有无外部泄漏的外部泄漏判断处理。在压力传感器未检测出压力,且排出侧流量传感器未检测出流量的情况下,判断为没有内部泄漏。在压力传感器未检测出压力,且排出侧流量传感器检测出流量的情况下,判断为有内部泄漏。在外部泄漏判断处理中,在累计供给流量与累计排出流量相同的情况下判断为没有外部泄漏。在累计供给流量大于累计排出流量的情况下判断为有外部泄漏。(Provided is a fluid flow path switching device capable of determining whether a fluid leak is an internal leak or an external leak. The fluid flow path switching device includes: a switching valve, a supply flow path, a discharge flow path, a supply-side flow sensor, a discharge-side flow sensor, a pressure sensor, and a leakage determination unit. The leakage determination unit executes an internal leakage determination process for determining whether or not there is an internal leakage and an external leakage determination process for determining whether or not there is an external leakage. When the pressure sensor does not detect the pressure and the discharge-side flow rate sensor does not detect the flow rate, it is determined that there is no internal leakage. When the pressure sensor does not detect the pressure and the discharge-side flow rate sensor detects the flow rate, it is determined that there is an internal leak. In the external leakage determination process, it is determined that there is no external leakage when the integrated supply flow rate is the same as the integrated discharge flow rate. When the integrated supply flow rate is larger than the integrated discharge flow rate, it is determined that there is an external leak.)

1. A fluid flow path switching device is characterized by comprising:

a switching valve that switches a flow path for supplying and discharging fluid to and from a pressure operation chamber of a fluid pressure cylinder;

a supply flow path that supplies fluid to the switching valve;

a discharge flow path that discharges the fluid from the switching valve to the outside;

a supply-side flow rate sensor that detects a flow rate of the fluid flowing through the supply flow path;

a discharge-side flow rate sensor that detects a flow rate of the fluid flowing through the discharge flow path;

a pressure sensor that detects a pressure of the discharge flow path; and

a leakage determination unit that determines leakage of the fluid;

the leakage determination section executes the following processing:

an internal leakage judgment process of judging whether there is an internal leakage; and

an external leakage judging process for judging the existence of external leakage,

in the internal leakage determination process, it is determined that there is no internal leakage when the pressure sensor does not detect a pressure and the discharge-side flow rate sensor does not detect a flow rate, and it is determined that there is an internal leakage when the pressure sensor does not detect a pressure and the discharge-side flow rate sensor detects a flow rate,

in the external leakage determination process, an integrated supply flow rate of the fluid supplied to the pressure acting chamber is calculated based on the flow rate detected by the supply-side flow rate sensor, and an integrated discharge flow rate of the fluid discharged from the pressure acting chamber is calculated based on the flow rate detected by the discharge-side flow rate sensor, and when the integrated supply flow rate is the same as the integrated discharge flow rate, it is determined that there is no external leakage, and when the integrated supply flow rate is larger than the integrated discharge flow rate, it is determined that there is external leakage.

2. A fluid flow path switching device is characterized by comprising:

a switching valve connected to a fluid cylinder having a 1 st pressure operation chamber and a 2 nd pressure operation chamber, and switching a flow path so as to supply a fluid to one of the 1 st pressure operation chamber and the 2 nd pressure operation chamber and discharge the fluid from the other pressure operation chamber;

a supply flow path that supplies fluid to the switching valve;

a discharge flow path that discharges the fluid from the switching valve to the outside;

a supply-side flow rate sensor that detects a flow rate of the fluid flowing through the supply flow path;

a discharge-side flow rate sensor that detects a flow rate of the fluid flowing through the discharge flow path;

a pressure sensor that detects a pressure of the discharge flow path; and

a leakage determination unit that determines leakage of the fluid;

the leakage determination section executes the following processing:

an internal leakage judgment process of judging whether there is an internal leakage; and

an external leakage judging process for judging the existence of external leakage,

in the internal leakage determination process, it is determined that there is no internal leakage when the pressure sensor does not detect a pressure and the discharge-side flow rate sensor does not detect a flow rate, and it is determined that there is an internal leakage when the pressure sensor does not detect a pressure and the discharge-side flow rate sensor detects a flow rate,

in the external leakage determination process, an integrated supply flow rate of the fluid supplied to one of the 1 st pressure acting chamber and the 2 nd pressure acting chamber is calculated based on the flow rate detected by the supply-side flow rate sensor, an integrated discharge flow rate of the fluid discharged from the other of the 1 st pressure acting chamber and the 2 nd pressure acting chamber is calculated based on the flow rate detected by the discharge-side flow rate sensor, and it is determined that there is no external leakage when a flow rate difference between the integrated supply flow rate and the integrated discharge flow rate is a predetermined value, and it is determined that there is external leakage when a flow rate difference between the integrated supply flow rate and the integrated discharge flow rate is greater than a predetermined value.

3. The flow channel switching device according to claim 1 or 2, further comprising:

a supply/discharge block in which a part of the supply flow path and a part of the discharge flow path are formed,

a plurality of the switching valves are arranged in parallel in the supply/discharge block,

the supply-side flow rate sensor, the discharge-side flow rate sensor, and the pressure sensor are integrated with the supply/discharge block.

4. The flow channel switching device according to claim 1 or 2, further comprising:

a manifold base in which a part of the supply channel and a part of the discharge channel are formed,

the switching valve is placed on the manifold base,

the supply-side flow sensor, the discharge-side flow sensor, and the pressure sensor are integrated with the manifold base.

5. The flow path switching device according to claim 1 or 2,

the supply flow path has a main supply flow path and a sub-supply flow path that branches from the main supply flow path and bypasses a part of the main supply flow path,

the flow path cross-sectional area of the sub supply flow path is smaller than the flow path cross-sectional area of the main supply flow path,

the supply-side flow rate sensor is provided in the sub-supply flow path.

6. The flow path switching device according to claim 1 or 2,

the discharge flow path has a main discharge flow path and a sub-discharge flow path that branches from the main discharge flow path and bypasses a part of the main discharge flow path,

the flow path cross-sectional area of the sub discharge flow path is smaller than the flow path cross-sectional area of the main discharge flow path,

the discharge-side flow sensor is provided in the sub-discharge flow path.

7. The flow path switching device according to claim 1 or 2,

a check valve that allows the fluid to flow from the switching valve to the outside and blocks the fluid from flowing from the outside to the switching valve is provided in the discharge flow path.

Technical Field

The present invention relates to a fluid flow path switching device.

Background

The fluid switching device is provided with: a switching valve that switches a flow path for supplying and discharging fluid to and from a pressure operation chamber of a fluid pressure cylinder; a supply flow path that supplies fluid to the switching valve; and a discharge flow path which discharges the fluid from the switching valve to the outside. In patent document 1, a flow rate sensor attached to a supply flow path detects a flow rate of a fluid flowing through the supply flow path, and the presence or absence of a leak is determined based on the flow rate detected by the flow rate sensor.

However, in the above structure, the following internal leakage may occur. Specifically, there are the following cases: due to deterioration of a seal (packing) of a valve body of the switching valve, a part of the fluid supplied from the supply flow path to the switching valve leaks to the discharge flow path without being supplied to the pressure operation chamber of the fluid pressure cylinder. Further, there are also the following cases: a part of the fluid supplied to the pressure acting chamber leaks from the pressure acting chamber due to deterioration of the seal of the piston of the fluid pressure cylinder. Further, the following external leakage may occur. Specifically, there are the following cases: due to a poor seal between the supply flow path and the switching valve, a part of the fluid flowing through the supply flow path leaks to the outside. Further, there are also the following cases: because of the poor sealing of the pipe connecting the switching valve and the fluid pressure cylinder, a part of the fluid flowing through the pipe leaks to the outside.

As described above, in patent document 1, the flow rate of the fluid flowing through the supply flow path is detected by the flow rate sensor, and it is possible to determine whether or not the fluid leakage has occurred. However, it is impossible to determine whether the fluid leakage is an internal leakage or an external leakage.

Documents of the prior art

Patent document

Patent document 1: japanese patent No. 3695381

Disclosure of Invention

Problems to be solved by the invention

An object of the present invention is to provide a fluid flow path switching device capable of determining whether a fluid leak is an internal leak or an external leak.

Means for solving the problems

In order to solve the above problem, according to a first aspect of the present invention, a fluid flow path switching device includes: a switching valve that switches a flow path for supplying and discharging fluid to and from a pressure operation chamber of a fluid pressure cylinder; a supply flow path that supplies the fluid to the switching valve; a discharge flow path for discharging the fluid from the switching valve to the outside; a supply-side flow rate sensor that detects a flow rate of the fluid flowing through the supply flow path; a discharge-side flow rate sensor that detects a flow rate of the fluid flowing through the discharge flow path; a pressure sensor that detects a pressure of the discharge flow path; and a leakage determination unit that determines whether or not the fluid is leaking. The leakage determination unit executes the following processing: an internal leakage determination process for determining the presence or absence of an internal leakage, and an external leakage determination process for determining the presence or absence of an external leakage. In the internal leakage determination process, the leakage determination unit determines that there is no internal leakage when the pressure sensor does not detect a pressure and the discharge-side flow rate sensor does not detect a flow rate. Further, the leakage determination unit determines that the internal leakage is present when the pressure sensor does not detect the pressure and the discharge-side flow rate sensor detects the flow rate. In the external leakage determination process, the leakage determination unit may calculate an integrated supply flow rate of the fluid supplied to the pressure operation chamber based on the flow rate detected by the supply-side flow rate sensor, and may calculate an integrated discharge flow rate of the fluid discharged from the pressure operation chamber based on the flow rate detected by the discharge-side flow rate sensor. The leakage determination unit determines that the external leakage does not occur when the integrated supply flow rate is the same as the integrated discharge flow rate. Further, the leakage determination unit determines that the external leakage is present when the integrated supply flow rate is larger than the integrated discharge flow rate.

In order to solve the above problem, according to a second aspect of the present invention, a fluid flow path switching device includes: a switching valve connected to a fluid cylinder having a 1 st pressure operation chamber and a 2 nd pressure operation chamber, and switching a flow path so as to supply a fluid to one of the 1 st pressure operation chamber and the 2 nd pressure operation chamber and discharge the fluid from the other pressure operation chamber; a supply flow path that supplies the fluid to the switching valve; a discharge flow path for discharging the fluid from the switching valve to the outside; a supply-side flow rate sensor that detects a flow rate of the fluid flowing through the supply flow path; a discharge-side flow rate sensor that detects a flow rate of the fluid flowing through the discharge flow path; a pressure sensor that detects a pressure of the discharge flow path; and a leakage determination unit that determines leakage of the fluid. The leakage determination unit executes the following processing: an internal leakage judgment process of judging whether there is an internal leakage; and an external leakage determination process for determining whether or not there is an external leakage. In the internal leakage determination process, the leakage determination unit determines that there is no internal leakage when the pressure sensor does not detect a pressure and the discharge-side flow rate sensor does not detect a flow rate. Further, the leakage determination unit determines that the internal leakage is present when the pressure sensor does not detect the pressure and the discharge-side flow rate sensor detects the flow rate. In the external leakage determination process, the leakage determination unit may calculate an integrated supply flow rate of the fluid supplied to one of the 1 st pressure acting chamber and the 2 nd pressure acting chamber based on the flow rate detected by the supply-side flow rate sensor, and may calculate an integrated discharge flow rate of the fluid discharged from the other of the 1 st pressure acting chamber and the 2 nd pressure acting chamber based on the flow rate detected by the discharge-side flow rate sensor. The leakage determination unit determines that the external leakage is not present when a flow rate difference between the integrated supply flow rate and the integrated discharge flow rate is a predetermined value. Further, the leakage determination unit determines that the external leakage is present when a flow rate difference between the integrated supply flow rate and the integrated discharge flow rate is larger than a predetermined value.

Drawings

Fig. 1 is a diagram for explaining a fluid flow path switching device according to an embodiment of the present invention.

Fig. 2 is a diagram for explaining the internal leakage determination process.

Fig. 3 is a diagram for explaining the internal leakage determination process.

Fig. 4 is a diagram for explaining the internal leakage determination process.

Fig. 5 is a diagram for explaining the internal leakage determination process.

Fig. 6 is a timing chart for explaining the internal leakage determination process.

Fig. 7 is a diagram for explaining the external leak determination process.

Fig. 8 is a diagram for explaining the external leak determination process.

Fig. 9 is a timing chart for explaining the external leak determination process.

Fig. 10 is a diagram for explaining a fluid flow path switching device according to another embodiment.

Detailed Description

Hereinafter, an embodiment in which the fluid flow path switching device is embodied will be described with reference to fig. 1 to 9.

As shown in fig. 1, the fluid flow path switching device 10 includes a supply/discharge block 11, a plurality of manifold bases 21, and a plurality of switching valves 30. The manifold bases 21 are arranged side by side on the supply/discharge block 11. The switching valves 30 are placed on the manifold bases 21. Therefore, the switching valves 30 are placed on the manifold bases 21. The plurality of switching valves 30 are provided in parallel in the supply/discharge block 11.

Each switching valve 30 has a supply port, a 1 st output port, a 2 nd output port, a 1 st discharge port, and a 2 nd discharge port. Each switching valve 30 is a well-known 5-port solenoid valve, and switches communication between ports as the spool reciprocates by turning on and off the power supply to the solenoid. A seal for sealing between the ports is mounted on the valve element. Each switching valve 30 switches the communication between the ports according to the switching position of the spool, thereby switching the flow path so as to supply and discharge the fluid to and from the 1 st pressure operation chamber 41 and the 2 nd pressure operation chamber 42 of each fluid pressure cylinder 40. Each switching valve 30 switches the flow path so as to supply the fluid to the 1 st pressure operation chamber 41 of the fluid cylinder 40 and discharge the fluid from the 2 nd pressure operation chamber 42 of the fluid cylinder 40. Each switching valve 30 switches the flow path so as to supply the fluid to the 2 nd pressure operation chamber 42 of the fluid cylinder 40 and discharge the fluid from the 1 st pressure operation chamber 41 of the fluid cylinder 40.

Each fluid pressure cylinder 40 includes a cylinder tube (cylinder tube)43, a piston 44 housed in the cylinder tube 43, and a piston rod 45 attached to the piston 44. The cylinder 43 is partitioned into a 1 st pressure operation chamber 41 and a 2 nd pressure operation chamber 42 by a piston 44. A seal, not shown, attached to the piston 44 is sealed between the 1 st pressure acting chamber 41 and the 2 nd pressure acting chamber 42.

The piston rod 45 moves integrally with the piston 44 with the reciprocation of the piston 44. The piston rod 45 can protrude and retract with respect to the cylinder 43 through the 2 nd pressure acting chamber 42. The maximum volume of the 2 nd pressure acting chamber 42 is smaller than the maximum volume of the 1 st pressure acting chamber 41 by the amount passed by the piston rod 45. Therefore, the maximum volume of the 1 st pressure acting chamber 41 is larger than the maximum volume of the 2 nd pressure acting chamber 42.

The supply/discharge block 11 has a 1 st collective supply port 12a and a 2 nd collective supply port 12 b. The supply/discharge block 11 has a collective supply passage 13. The concentrated supply channel 13 includes a main concentrated supply channel 13a and a sub concentrated supply channel 13b branched from the main concentrated supply channel 13a and bypassing a part of the main concentrated supply channel 13 a. The 1 st end of the main collective supply channel 13a is connected to the 1 st collective supply port 12 a. The 2 nd end of the main collective supply passage 13a is connected to the 2 nd collective supply port 12 b. The cross-sectional flow area of the sub-concentrated supply flow path 13b is smaller than that of the main concentrated supply flow path 13 a. The 1 st collective supply port 12a is connected to a fluid pressure device 15 via an external supply flow path 14. The external supply passage 14 is, for example, a pipe.

The supply/discharge block 11 has a 1 st collective discharge port 16a, a 2 nd collective discharge port 16b, and a collective external discharge port 16 c. The supply/discharge block 11 has a collective discharge flow path 17. The concentrated discharge passage 17 includes a main concentrated discharge passage 17a and a sub concentrated discharge passage 17b that branches from the main concentrated discharge passage 17a and bypasses a part of the main concentrated discharge passage 17 a. The 1 st end portion of the main concentrated discharge channel 17a is branched into a 1 st branch connecting channel 171a connected to the 1 st concentrated discharge port 16a and a 2 nd branch connecting channel 172a connected to the 2 nd concentrated discharge port 16 b. The 2 nd end of the main concentrated discharge passage 17a is connected to the concentrated external discharge port 16 c. The flow path cross-sectional area of the sub-concentrated discharge flow path 17b is smaller than that of the main concentrated discharge flow path 17 a. The collective external discharge port 16c is connected to the outside via an external discharge flow path 18. The external discharge flow path 18 is, for example, a pipe.

Each manifold base 21 has a base supply channel 22, a 1 st base output channel 23, a 2 nd base output channel 24, a 1 st base discharge channel 25, and a 2 nd base discharge channel 26. The base supply channel 22, the 1 st base output channel 23, the 2 nd base output channel 24, the 1 st base discharge channel 25, and the 2 nd base discharge channel 26 of each manifold base 21 are connected to each switching valve 30. Specifically, the base supply channel 22 is connected to the supply port of the switching valve 30, and the 1 st base output channel 23 is connected to the 1 st output port of the switching valve 30. The 2 nd base output flow path 24 is connected to the 2 nd output port of the switching valve 30. The 1 st base discharge channel 25 is connected to the 1 st discharge port of the switching valve 30. The 2 nd base discharge flow path 26 is connected to the 2 nd discharge port of the switching valve 30.

The base supply passage 22 of the manifold base 21 disposed at the position closest to the supply/discharge block 11 is connected to the 2 nd concentrated supply port 12b of the supply/discharge block 11. The base supply passages 22 of the adjacent manifold bases 21 communicate with each other. Therefore, the base supply channel 22 of each manifold base 21 is connected to the 2 nd collective supply port 12b of the supply/discharge block 11.

The fluid compressed by the fluid pressure device 15 is supplied to each switching valve 30 through the external supply passage 14, the 1 st collective supply port 12a, the collective supply passage 13, the 2 nd collective supply port 12b, and each base supply passage 22. Therefore, the external supply channel 14, the 1 st collective supply port 12a, the collective supply channel 13, the 2 nd collective supply port 12b, and the respective susceptor supply channels 22 constitute supply channels 27 for supplying the fluid to the respective switching valves 30. A part of the supply passage 27 is formed in the supply/discharge block 11. Further, each manifold base 21 is formed with a part of the supply flow path 27. The supply flow path 27 includes: a main concentrated supply channel 13a serving as a main supply channel; and a sub-concentrated supply channel 13b as a sub-supply channel that branches from the main supply channel and bypasses a part of the main supply channel.

The 1 st base discharge passage 25 of the manifold base 21 disposed at the position closest to the supply and discharge block 11 is connected to the 1 st concentrated discharge port 16a of the supply and discharge block 11. The 1 st base discharge passages 25 of the adjacent manifold bases 215 communicate with each other. Therefore, the 1 st base discharge channel 25 of each manifold base 21 is connected to the 1 st collective discharge port 16a of the supply and discharge block 11.

The 2 nd base discharge passage 26 of the manifold base 21 disposed at the position closest to the supply and discharge block 11 is connected to the 2 nd concentrated discharge port 16b of the supply and discharge block 11. The 2 nd base discharge passages 26 of the adjacent manifold bases 21 communicate with each other. Therefore, the 2 nd base discharge channels 26 of the manifold bases 21 are connected to the 2 nd collective discharge port 16b of the supply and discharge block 11.

The fluid discharged from each switching valve 30 to each 1 st base discharge channel 25 is discharged to the outside through the 1 st base discharge channel 25, the 1 st collective discharge port 16a, the collective discharge channel 17, the collective external discharge port 16c, and the external discharge channel 18. The fluid discharged from each switching valve 30 to each 2 nd base discharge channel 26 is discharged to the outside through each 2 nd base discharge channel 26, the 2 nd collective discharge port 16b, the collective discharge channel 17, the collective external discharge port 16c, and the external discharge channel 18. Therefore, the 1 st base discharge port 25, the 1 st collective discharge port 16a, the 2 nd base discharge flow path 26, the 2 nd collective discharge port 16b, the collective discharge flow path 17, the collective external discharge port 16c, and the external discharge flow path 18 constitute a discharge flow path 28 that discharges the fluid from the respective switching valves 30 to the outside. A part of the discharge flow path 28 is formed in the supply and discharge block 11. Further, a part of the discharge flow path 28 is formed in each manifold base 21. The discharge flow path 28 includes: a main concentrated discharge passage 17a as a main discharge passage; and a sub concentrated discharge passage 17b as a sub discharge passage branched from the main discharge passage and bypassing a part of the main discharge passage.

A check valve 18a is provided in the external discharge flow path 18. The check valve 18a allows the fluid to flow from the collective outer discharge port 16c to the outside via the outer discharge flow path 18, and blocks the fluid from flowing from the outside to the collective outer discharge port 16c via the outer discharge flow path 18. Therefore, the check valve 18a allows the fluid to flow from the switching valve 30 to the outside, and blocks the fluid from flowing from the outside to the switching valve 30.

The 1 st base output flow path 23 of each manifold base 21 is connected to the 1 st pressure operation chamber 41 of each fluid pressure cylinder 40 via each 1 st external output flow path 46. Each 1 st external output channel 46 is, for example, a pipe. The 2 nd base output flow path 24 of each manifold base 21 is connected to the 2 nd pressure operation chamber 42 of each fluid pressure cylinder 40 via each 2 nd external output flow path 47. Each 2 nd external output channel 47 is, for example, a pipe.

When the solenoid is energized and turned on by the switching valve 30, the valve body of the switching valve 30 is switched to a first switching position where the supply port and the 1 st output port are communicated and the 2 nd output port and the 2 nd discharge port are communicated. When the valve body of the switching valve 30 is switched to the first switching position, the seal members of the valve body seal between the supply port and the 2 nd output port and between the 1 st output port and the 1 st discharge port.

The fluid output from the switching valve 30 to the 1 st base output flow path 23 via the 1 st output port is supplied to the 1 st pressure operation chamber 41 of the fluid cylinder 40 via the 1 st external output flow path 46. In this way, the piston 44 of the fluid pressure cylinder 40 moves so as to increase the volume of the 1 st pressure operation chamber 41. Thereby, the volume of the 2 nd pressure acting chamber 42 is reduced, and the fluid in the 2 nd pressure acting chamber 42 of the fluid cylinder 40 is discharged to the 2 nd susceptor discharge flow path 26 through the 2 nd external discharge flow path 47, the 2 nd outlet port, and the 2 nd discharge port.

When the solenoid is de-energized by the switching valve 30, the spool of the switching valve 30 is switched to a second switching position where the supply port and the 2 nd output port are communicated and the 1 st output port and the 1 st discharge port are communicated. When the valve body of the switching valve 30 is switched to the second switching position, the seal members of the valve body seal between the supply port and the 1 st output port and between the 2 nd output port and the 2 nd discharge port.

The fluid output from the switching valve 30 to the 2 nd base output passage 24 via the 2 nd output port is supplied to the 2 nd pressure working chamber 42 of the fluid cylinder 40 via the 2 nd external output passage 47. In this way, the piston 44 of the fluid pressure cylinder 40 moves in such a manner as to increase the volume of the 2 nd pressure apply chamber 42. Thereby, the volume of the 1 st pressure operation chamber 41 is reduced, and the fluid in the 1 st pressure operation chamber 41 of the fluid cylinder 40 is discharged to the 1 st base discharge passage 25 via the 1 st external discharge passage 46, the 1 st output port, and the 1 st discharge port.

The fluid flow path switching device 10 includes a microcomputer 50 (MPU). The microcomputer 50 is built in the supply and discharge block 11. The microcomputer 50 is electrically connected to an external control device 51.

The fluid flow switching device 10 includes a supply-side flow sensor 61. The supply-side flow rate sensor 61 is provided in the sub-collective supply channel 13b of the collective supply channel 13. The supply-side flow rate sensor 61 detects the flow rate of the fluid flowing through the sub-collective supply channel 13 b. Therefore, the supply-side flow sensor 61 detects the flow rate of the fluid flowing through the supply flow path 27. The supply-side flow rate sensor 61 is built in the supply/discharge block 11. Therefore, the supply-side flow sensor 61 is integrated with the supply and discharge block 11. The supply-side flow rate sensor 61 is electrically connected to the microcomputer 50. Information on the flow rate detected by the supply-side flow rate sensor 61 is sent to the microcomputer 50.

The fluid flow switching device 10 includes a discharge-side flow rate sensor 62. The discharge-side flow rate sensor 62 is provided in the sub-concentrated discharge flow path 17b of the concentrated discharge flow path 17. The discharge-side flow rate sensor 62 detects the flow rate of the fluid flowing through the sub-collective discharge flow path 17 b. Therefore, the discharge-side flow rate sensor 62 detects the flow rate of the fluid flowing through the discharge flow path 28. The discharge-side flow rate sensor 62 is built in the supply/discharge block 11. Therefore, the discharge-side flow rate sensor 62 is integrated with the supply/discharge block 11. The discharge-side flow sensor 62 is electrically connected to the microcomputer 50. Information on the flow rate detected by the discharge-side flow rate sensor 62 is sent to the microcomputer 50.

The discharge flow path 28 has a pressure detection flow path 19. The pressure detection flow path 19 is formed in the supply/discharge block 11. The pressure detection flow path 19 branches from a portion between the connection point of the main concentrated discharge flow path 17a and the sub concentrated discharge flow path 7b and the 1 st end of the main concentrated discharge flow path 17 a.

The fluid flow switching device 10 includes a pressure sensor 63. The pressure sensor 63 is provided in the pressure detection flow path 19. The pressure sensor 63 detects the pressure of the pressure detection flow path 19. Therefore, the pressure sensor 63 detects the pressure of the discharge flow path 28. The pressure sensor 63 is built in the supply/discharge block 11. Therefore, the pressure sensor 63 is integrated with the supply/discharge block 11. The pressure sensor 63 is electrically connected to the microcomputer 50. Information on the pressure detected by the pressure sensor 63 is sent to the microcomputer 50.

The microcomputer 50 stores a program for executing the following processes in advance: it is determined whether or not the movement of the piston 44 of the fluid pressure cylinder 40 is in a transient state based on the change in the pressure of the discharge flow path 28 detected by the pressure sensor 63. When the pressure sensor 63 detects the pressure, the microcomputer 50 determines that the movement of the piston 44 of the fluid pressure cylinder 40 is in the transition state. When the pressure sensor 63 does not detect the pressure, the microcomputer 50 determines that the piston 44 of the fluid pressure cylinder 40 has reached the stroke end (stroke end) and the piston 44 is in the stopped state.

The microcomputer 50 stores a program for executing the following processes in advance: an internal leakage determination process for determining whether or not there is an internal leakage, and an external leakage determination process for determining whether or not there is an external leakage. Therefore, the microcomputer 50 functions as a leakage determination unit that determines the leakage of the fluid.

The "internal leakage" refers to, for example, a case where a part of the fluid supplied from the supply passage 27 to the switching valve 30 leaks to the discharge passage 28 without being supplied to the pressure operation chambers 41 and 42 of the fluid cylinder 40 due to deterioration of a seal of the valve body of the switching valve 30. The "internal leakage" refers to, for example, a case where a part of the fluid supplied to the 1 st pressure operation chamber 41 leaks to the 2 nd pressure operation chamber 42 or a part of the fluid supplied to the 2 nd pressure operation chamber 42 leaks to the 1 st pressure operation chamber 41 due to deterioration of the seal of the piston 44 of the fluid pressure cylinder 40.

The "external leakage" refers to, for example, a case where a part of the fluid flowing through the supply flow path 27 leaks to the outside due to a poor seal between the supply flow path 27 and the switching valve 30, or a case where a part of the fluid flowing through the pipe leaks to the outside due to a poor seal of the pipe connecting the switching valve 30 and the fluid cylinder 40.

The microcomputer 50 stores a program for executing the following processes in advance: in the internal leakage determination process, when the pressure sensor 63 does not detect the pressure and the discharge-side flow rate sensor 62 does not detect the flow rate, it is determined that there is no internal leakage. Further, the microcomputer 50 is stored in advance with a program that executes the following processing: in the internal leakage determination process, if the pressure sensor 63 does not detect the pressure and the discharge-side flow rate sensor 62 detects the flow rate, it is determined that there is an internal leakage.

In order to avoid erroneous determination regarding the pressure detection in the discharge flow path 28, the pressure sensor 63 is, for example, a sensor that does not detect a slight change in the pressure in the discharge flow path 28 when the fluid leaks into the discharge flow path 28 due to internal leakage.

The microcomputer 50 stores a program for executing the following processes in advance: when the pressure sensor 63 detects the pressure and determines that the movement of the piston 44 of the fluid pressure cylinder 40 is in the transient state, the internal leakage determination process is not executed. Further, the microcomputer 50 is stored in advance with a program that executes the following processing: when the pressure sensor 63 does not detect the pressure and determines that the piston 44 of the fluid pressure cylinder 40 is in the stopped state, the internal leakage determination process is executed.

The microcomputer 50 stores a program for executing the following processes in advance: when it is determined that there is an internal leak in the internal leak determination process, the flow rate detected by the discharge-side flow rate sensor 62 is stored as an internal leak amount.

The microcomputer 50 stores a program for executing the following processes in advance: in the external leakage determination process, the integrated supply flow rate of the fluid supplied to the 1 st pressure acting chamber 41 is calculated based on the flow rate detected by the supply-side flow rate sensor 61, and the integrated discharge flow rate of the fluid discharged from the 1 st pressure acting chamber 41 is calculated based on the flow rate detected by the discharge-side flow rate sensor 62. Further, the microcomputer 50 is stored in advance with a program that executes the following processing: when the integrated supply flow rate is the same as the integrated discharge flow rate, it is determined that there is no external leak, and when the integrated supply flow rate is larger than the integrated discharge flow rate, it is determined that there is an external leak.

Specifically, the microcomputer 50 stores a program for executing the following processes in advance: in the external leakage determination process, after the switching valve 30 is energized to the solenoid, the cumulative supply flow rate of the fluid supplied to the 1 st pressure acting chamber 41 is calculated based on the flow rate detected by the supply-side flow rate sensor 61. Further, the microcomputer 50 is stored in advance with a program that executes the following processing: in the external leakage determination process, after the switching valve 30 is de-energized to the solenoid, the integrated discharge flow rate of the fluid discharged from the 1 st pressure acting chamber 41 is calculated based on the flow rate detected by the discharge-side flow rate sensor 62. The microcomputer 50 stores the calculated integrated supply flow rate and the integrated discharge flow rate, respectively. The microcomputer 50 stores a program for executing the following processes in advance: in the external leakage determination process, the integrated supply flow rate of the fluid supplied to the 1 st pressure acting chamber 41 after the energization of the solenoid by the switching valve 30 is turned on is compared with the integrated discharge flow rate of the fluid discharged from the 1 st pressure acting chamber 41 after the energization of the solenoid by the switching valve 30 is turned off. The microcomputer 50 stores a program for executing the following processes in advance: when the integrated supply flow rate is the same as the integrated discharge flow rate, it is determined that there is no external leak. Further, the microcomputer 50 is stored in advance with a program that executes the following processing: when the integrated supply flow rate is larger than the integrated discharge flow rate, it is determined that there is an external leak.

Further, the microcomputer 50 is stored in advance with a program that executes the following processing: in the external leakage determination process, the integrated supply flow rate of the fluid supplied to the 2 nd pressure acting chamber 42 is calculated based on the flow rate detected by the supply-side flow rate sensor 61, and the integrated discharge flow rate of the fluid discharged from the 2 nd pressure acting chamber 42 is calculated based on the flow rate detected by the discharge-side flow rate sensor 62. The microcomputer 50 stores a program for executing the following processes in advance: when the integrated supply flow rate is the same as the integrated discharge flow rate, it is determined that there is no external leak, and when the integrated supply flow rate is larger than the integrated discharge flow rate, it is determined that there is an external leak.

Specifically, the microcomputer 50 stores a program for executing the following processes in advance: in the external leakage determination, the integrated supply flow rate of the fluid supplied to the 2 nd pressure acting chamber 42 is calculated based on the flow rate detected by the supply-side flow rate sensor 61 after the energization of the solenoid by the switching valve 30 is turned off. Further, the microcomputer 50 is stored in advance with a program that executes the following processing: in the external leakage determination process, after the switching valve 30 is energized to the solenoid, the cumulative discharge flow rate discharged from the 2 nd pressure acting chamber 42 is calculated based on the flow rate detected by the discharge-side flow rate sensor 62. The microcomputer 50 stores the calculated integrated supply flow rate and the integrated discharge flow rate, respectively. The microcomputer 50 stores a program for executing the following processes in advance: in the external leakage determination process, the integrated supply flow rate of the fluid supplied to the 2 nd pressure apply chamber 42 after the energization of the solenoid is turned off by the switching valve 30 is compared with the integrated discharge flow rate of the fluid discharged from the 2 nd pressure apply chamber 42 after the energization of the solenoid is turned on by the switching valve 30. The microcomputer 50 stores a program for executing the following processes in advance: when the integrated supply flow rate is the same as the integrated discharge flow rate, it is determined that there is no external leak. Further, the microcomputer 50 is stored in advance with a program that executes the following processing: when the integrated supply flow rate is larger than the integrated discharge flow rate, it is determined that there is an external leak.

The microcomputer 50 stores a program for executing the following processes in advance: the external leakage determination process is always executed regardless of the presence or absence of detection by the pressure sensor 63. Therefore, the microcomputer 50 always executes the external leakage determination process regardless of whether the movement of the piston 44 of the fluid pressure cylinder 40 is in the transition state or the piston 44 of the fluid pressure cylinder 40 is in the stop state.

The microcomputer 50 stores in advance a program that executes the following processing: when it is determined that there is an external leak in the external leak determination process, the difference between the integrated supply flow rate and the integrated discharge flow rate is calculated, and the calculated flow rate is stored as the external leak amount.

Next, the operation of the present embodiment will be described.

In the following description of the operation, only the operation related to the set of the switching valve 30 and the fluid pressure cylinder 40 will be described for the sake of simplicity. The supply channel 27 and the discharge channel 28 are simplified from fig. 2 onward.

First, a method of determining the presence or absence of an internal leak by the microcomputer 50 will be described together with the operation of the present embodiment.

As shown in fig. 2, when the switching valve 30 is de-energized to the solenoid, the switching valve 30 is switched from the first switching position to the second switching position. Thus, the fluid in the 1 st pressure acting chamber 41 is discharged to the outside through the discharge flow path 28, and the fluid that has passed through the supply flow path 27 is supplied to the 2 nd pressure acting chamber 42. As a result, the piston rod 45 is in the most retracted state with respect to the cylinder 43.

As shown in fig. 3, when the switching valve 30 is energized to the solenoid, the switching valve 30 is switched from the second switching position to the first switching position. Thus, the fluid having passed through the supply flow path 27 is supplied to the 1 st pressure acting chamber 41, and the fluid of the 2 nd pressure acting chamber 42 is discharged to the outside through the discharge flow path 28. As a result, the amount of protrusion of the piston rod 45 with respect to the cylinder 43 gradually increases.

At this time, since the pressure sensor 63 detects the pressure, the microcomputer 50 determines that the movement of the piston 44 of the fluid pressure cylinder 40 is in the transition state. Therefore, the microcomputer 50 does not perform the internal leakage determination process.

As shown in fig. 4, when the piston rod 45 is in the most protruding state with respect to the cylinder tube 43, the piston 44 of the fluid pressure cylinder 40 reaches the stroke end, and the piston 44 stops. At this time, since the pressure sensor 63 does not detect the pressure, the microcomputer 50 determines that the piston 44 of the fluid pressure cylinder 40 is in the stopped state, and executes the internal leakage determination process. Here, when the pressure sensor 63 does not detect the pressure and the discharge-side flow rate sensor 62 does not detect the flow rate, the microcomputer 50 determines that there is no internal leakage.

As shown in fig. 5, in the internal leakage determination process, when the pressure sensor 63 does not detect the pressure and the discharge-side flow rate sensor 62 detects the flow rate, the microcomputer 50 determines that there is an internal leakage. In this case, it can be considered that: although the piston 44 of the fluid cylinder 40 is stopped, a part of the fluid supplied from the supply passage 27 to the switching valve 30 is not supplied to the 1 st pressure operation chamber 41 of the fluid cylinder 40 but leaks to the discharge passage 28 due to, for example, deterioration of a seal of a valve body of the switching valve 30. Further, it can be considered that: although the piston 44 of the fluid pressure cylinder 40 is stopped, for example, a part of the fluid in the 1 st pressure operation chamber 41 leaks to the 2 nd pressure operation chamber 42 due to deterioration of the seal of the piston 44 of the fluid pressure cylinder 40, and leaks from the 2 nd pressure operation chamber 42 to the discharge flow path 28. Therefore, it can be considered that the internal leakage occurs.

As shown in fig. 6, when it is determined that there is an internal leak in the internal leak determination process, the microcomputer 50 stores the flow rate Qx detected by the discharge-side flow rate sensor 62 as the internal leak amount. The microcomputer 50 transmits the flow rate Qx detected by the discharge-side flow rate sensor 62 to the external control device 51. The external control device 51 receives the flow rate Qx as the internal leakage amount, and notifies the operator of an abnormality.

Next, a method of determining the presence or absence of an external leak by the microcomputer 50 will be described together with the operation of the present embodiment.

As shown in fig. 7, when the switching valve 30 is energized to the solenoid, the switching valve 30 is switched to the first switching position, the fluid passing through the supply passage 27 is supplied to the 1 st pressure operation chamber 41, and the fluid passing through the 2 nd pressure operation chamber 42 is discharged to the outside through the discharge passage 28. Thereby, the piston rod 45 is in a state of being most protruded with respect to the cylinder 43.

At this time, the microcomputer 50 calculates the integrated supply flow rate of the fluid supplied to the 1 st pressure acting chamber 41 based on the flow rate detected by the supply-side flow rate sensor 61 in the external leakage determination process. Further, the microcomputer 50 calculates the integrated discharge flow rate of the fluid discharged from the 2 nd pressure acting chamber 42 based on the flow rate detected by the discharge-side flow rate sensor 62 in the external leakage determination process. In this way, the microcomputer 50 calculates the cumulative supply flow rate of the fluid supplied to the 1 st pressure acting chamber 41 and the cumulative discharge flow rate of the fluid discharged from the 2 nd pressure acting chamber 42 after the switching valve 30 is energized to the solenoid. The microcomputer 50 stores the calculated integrated supply flow rate and integrated discharge flow rate, respectively.

As shown in fig. 8, when the switching valve 30 is turned off from the energization to the solenoid, the switching valve 30 is switched from the first switching position to the second switching position, the fluid discharge passage 28 of the 1 st pressure operation chamber 41 is discharged to the outside, and the fluid passing through the supply passage 27 is supplied to the 2 nd pressure operation chamber 42. Thereby, the piston rod 45 is in the most retracted state with respect to the cylinder 43.

At this time, the microcomputer 50 calculates the integrated supply flow rate of the fluid supplied to the 2 nd pressure acting chamber 42 based on the flow rate detected by the supply-side flow rate sensor 61 in the external leakage determination process. Further, the microcomputer 50 calculates the integrated discharge flow rate of the fluid discharged from the 1 st pressure acting chamber 41 based on the flow rate detected by the discharge-side flow rate sensor 62 in the external leakage determination process. In this way, the microcomputer 50 calculates the cumulative supply flow rate of the fluid supplied to the 2 nd pressure acting chamber 42 and the cumulative discharge flow rate of the fluid discharged from the 1 st pressure acting chamber 41 after the switching valve 30 is turned off from energizing the solenoid. The microcomputer 50 stores the calculated integrated supply flow rate and integrated discharge flow rate, respectively.

As shown in fig. 9, in the external leakage determination process, the microcomputer 50 compares the integrated supply flow rate of the fluid supplied to the 1 st pressure acting chamber 41 after the energization of the solenoid is turned on by the switching valve 30 with the integrated discharge flow rate of the fluid discharged from the 1 st pressure acting chamber 41 after the energization of the solenoid is turned off by the switching valve 30. When the integrated supply flow rate is the same as the integrated discharge flow rate, the microcomputer 50 determines that there is no external leak. On the other hand, as shown by the two-dot chain line in fig. 9, when the integrated supply flow rate is larger than the integrated discharge flow rate, the microcomputer 50 determines that there is an external leak.

In the external leakage determination process, the microcomputer 50 compares the integrated supply flow rate of the fluid supplied to the 2 nd pressure apply chamber 42 after the energization of the solenoid is turned off by the switching valve 30 with the integrated discharge flow rate of the fluid discharged from the 2 nd pressure apply chamber 42 after the energization of the solenoid is turned on by the switching valve 30. When the integrated supply flow rate is the same as the integrated discharge flow rate, the microcomputer 50 determines that there is no external leak. On the other hand, as shown by the chain line in fig. 9, when the integrated supply flow rate is larger than the integrated discharge flow rate, the microcomputer 50 determines that there is an external leak. That is, it can be considered that: for example, a part of the fluid flowing through the supply passage 27 leaks to the outside due to a poor seal between the supply passage 27 and the switching valve 30, or a part of the fluid flowing through the pipe leaks to the outside due to a poor seal of the pipe connecting the switching valve 30 and the fluid cylinder 40.

When it is determined that there is an external leak in the external leak determination process, the microcomputer 50 calculates a difference between the integrated supply flow rate and the integrated discharge flow rate, and stores the calculated flow rate as an external leak amount. The microcomputer 50 transmits the calculated external leakage amount to the external control device 51. The external control device 51 receives the external leak amount and notifies the operator of an abnormality.

The above embodiment can obtain the following effects.

(1) In the internal leakage determination process, when the pressure sensor 63 does not detect the pressure and the discharge-side flow rate sensor 62 does not detect the flow rate, the microcomputer 50 determines that there is no internal leakage. When the pressure sensor 63 does not detect a pressure and the discharge-side flow rate sensor 62 detects a flow rate, the microcomputer 50 determines that there is an internal leak. Further, the microcomputer 50 detects the integrated supply flow rate of the fluid supplied to the 1 st pressure acting chamber 41 based on the flow rate detected by the supply-side flow rate sensor 61 in the external leakage determination process, and detects the integrated discharge flow rate of the fluid discharged from the 1 st pressure acting chamber 41 based on the flow rate detected by the discharge-side flow rate sensor 62. When the integrated supply flow rate is the same as the integrated discharge flow rate, the microcomputer 50 determines that there is no external leak. When the integrated supply flow rate is larger than the integrated discharge flow rate, the microcomputer 50 determines that there is an external leak. Thus, in the fluid flow path switching device 10, it is possible to determine whether the fluid leakage is internal leakage or external leakage.

(2) The supply-side flow rate sensor 61, the discharge-side flow rate sensor 62, and the pressure sensor 63 are integrated with the supply/discharge block 11. Thus, the entire fluid flow path switching device 10 can be made more compact as compared to a case where the supply-side flow rate sensor 61, the discharge-side flow rate sensor 62, and the pressure sensor 63 are integrated with each manifold base 21.

(3) The cross-sectional flow area of the sub-concentrated supply flow path 13b is smaller than that of the main concentrated supply flow path 13 a. The supply-side flow rate sensor 61 is provided in the sub-collective supply flow path 13 b. This enables the supply-side flow rate sensor 61 to be a small sensor, and thus the entire fluid flow path switching device 10 can be made compact.

(4) The flow path cross-sectional area of the sub-concentrated discharge flow path 17b is smaller than that of the main concentrated discharge flow path 17 a. The discharge-side flow rate sensor 62 is provided in the sub-concentrated discharge flow path 17 b. This enables the discharge-side flow sensor 62 to be a small sensor, and thus the entire fluid flow switching device 10 can be made compact.

(5) The external discharge flow path 18 is provided with a check valve 18a, and the check valve 18a allows the fluid to flow from the switching valve 30 to the outside and blocks the fluid from flowing from the outside to the switching valve 30. Thus, even when a plurality of fluid flow path switching devices 10 are arranged side by side and the external discharge flow paths 18 of the respective fluid flow path switching devices 10 are connected to each other, the check valve 18a can prevent the fluid discharged to the external discharge flow path 18 by another fluid flow path switching device 10 from flowing back to the switching valve 30 through the external discharge flow path 18 of the own fluid flow path switching device 10.

The above embodiment can be modified as follows. The above-described embodiments and the following modifications can be combined and implemented within a range not technically contradictory to each other.

The microcomputer 50 calculates the integrated supply flow rate of the fluid supplied to the 1 st pressure acting chamber 41 based on the flow rate detected by the supply-side flow rate sensor 61, and calculates the integrated discharge flow rate of the fluid discharged from the 2 nd pressure acting chamber 42 based on the flow rate detected by the discharge-side flow rate sensor 62 in the external leakage judgment process. Then, in the case where the flow rate difference between the integrated supply flow rate and the integrated discharge flow rate is a predetermined value, the microcomputer 50 can determine that there is no external leakage. In the case where the flow rate difference between the integrated supply flow rate and the integrated discharge flow rate is larger than a predetermined value, the microcomputer 50 can determine that there is an external leak.

Specifically, in the external leakage determination process, the microcomputer 50 compares the flow rate difference between the cumulative supply flow rate of the fluid supplied to the 1 st pressure acting chamber 41 after the switching valve 30 is energized to the solenoid and the cumulative discharge flow rate of the fluid discharged from the 2 nd pressure acting chamber 42. When the difference between the integrated supply flow rate and the integrated discharge flow rate is a predetermined value, the microcomputer 50 determines that there is no external leak. On the other hand, when the difference between the integrated supply flow rate and the integrated discharge flow rate is larger than the predetermined value, the microcomputer 50 determines that there is an external leak. Accordingly, even if the maximum volume of the 1 st pressure acting chamber 41 and the maximum volume of the 2 nd pressure acting chamber 42 are configured to be different from each other, the external leakage can be determined using the integrated supply flow rate of the 1 st pressure acting chamber 41 and the integrated discharge flow rate of the 2 nd pressure acting chamber 42 at the same timing, and therefore, the external leakage can be efficiently determined.

As shown in fig. 10, the supply-side flow rate sensor 61, the discharge-side flow rate sensor 62, and the pressure sensor 63 may be integrated with the manifold bases 21, respectively. In this case, the supply-side flow rate sensors 61 are provided in the base supply flow paths 22 of the manifold bases 21. Further, the discharge-side flow rate sensors 62 and the pressure sensors 63 are provided in the 1 st susceptor discharge flow channel 25 and the 2 nd susceptor discharge flow channel 26 of the manifold susceptors 21, respectively. This makes it possible to determine which manifold base 21 has a fluid leak, and to determine whether the fluid leak is an internal leak or an external leak.

The supply-side flow rate sensor 61 may be provided in the main collective supply channel 13 a. In this case, the collective supply channel 13 may not have the sub-collective supply channel 13 b.

The discharge-side flow rate sensor 62 may be provided in the main concentrated discharge channel 17 a. In this case, the concentrated discharge channel 17 may not have the sub-concentrated discharge channel 17 b.

The check valve 18a may not be provided in the external discharge flow path 18 of the fluid flow path switching device 10.

Each switching valve 30 may be a 3-port solenoid valve. In this case, each switching valve 30 switches the flow path so as to supply and discharge the fluid to and from only the 1 st pressure operation chamber 41 of each fluid cylinder 40. Therefore, in this case, each fluid pressure cylinder 40 is a spring-type one-way cylinder.

Description of the symbols

10 fluid flow path switching device

11 supply and discharge block

12a 1 st centralized supply port

12b 2 nd concentrated supply port

13 concentrated supply flow path

13a main concentrated supply channel

13b sub-concentrated supply channel

14 external supply flow path

15 fluid pressure device

16a 1 st centralized exhaust port

16b 2 nd centralized exhaust port

16c centralized external exhaust port

17 concentrated discharge flow path

17a main concentrated discharge flow path

17b sub-concentrated discharge channel

18 external discharge flow path

18a check valve

19 pressure detection flow path

21 manifold base

22 base supply flow path

23 st base output flow path

24 nd 2 nd base output flow path

25 st base discharge channel

26 nd 2 nd base discharge channel

27 supply flow path

28 discharge flow path

30 switching valve

40 fluid pressure cylinder

41 st pressure action chamber

42 nd 2 nd pressure acting chamber

43 cylinder barrel

44 piston

45 piston rod

46 1 st external output flow path

47 nd 2 external output flow path

50 micro-computer

51 external control device

61 supply side flow sensor

62 discharge side flow sensor

63 pressure sensor

171a 1 st branch connecting channel

172a 2 nd branch connection channel