JP7254745B2 - Fluid flow switching device - Google Patents

Description

The present invention relates to a fluid flow switching device.

The fluid switching device includes a switching valve for switching a flow path for supplying and discharging fluid to and from the pressure action chamber of the fluid pressure cylinder, a supply flow path for supplying fluid to the switching valve, and discharging the fluid from the switching valve to the outside. and a discharge channel. Further, for example, in Patent Document 1, a flow sensor is attached to a supply channel, the flow rate of the fluid flowing through the supply channel is detected by the flow sensor, and the presence or absence of fluid leakage is determined based on the flow rate detected by the flow sensor. are doing.

Japanese Patent No. 3695381

By the way, for example, due to deterioration of the packing of the valve body of the switching valve, part of the fluid supplied from the supply channel to the switching valve leaks to the discharge channel without being supplied to the pressure action chamber of the fluid pressure cylinder. In some cases, internal leakage may occur, such as leakage of a portion of the fluid supplied to the pressure action chamber from the pressure action chamber due to deterioration of the packing of the piston of the fluid pressure cylinder. In addition, for example, due to poor sealing between the supply channel and the switching valve, part of the fluid flowing through the supply channel leaks to the outside, or sealing failure of the pipe connecting the switching valve and the fluid pressure cylinder causes External leakage may occur, such as part of the fluid flowing through the piping leaking to the outside.

In this way, when either an internal leak or an external leak occurs, it can be determined that there is a fluid leak only by detecting the flow rate of the fluid flowing through the supply channel with a flow sensor as in Patent Document 1. Even if it is determined, there is a problem that it cannot be determined whether the fluid leak is an internal leak or an external leak.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a fluid flow switching device capable of determining whether a fluid leak is an internal leak or an external leak. .

A fluid flow path switching device for solving the above problems includes a switching valve for switching flow paths for supplying and discharging fluid to and from a pressure action chamber of a fluid pressure cylinder; a supply flow path for supplying fluid to the switching valve; A discharge flow path for discharging the fluid from the switching valve to the outside, a supply-side flow sensor for detecting the flow rate of the fluid flowing through the supply flow path, and a discharge-side flow sensor for detecting the flow rate of the fluid flowing through the discharge flow path. a pressure sensor for detecting the pressure in the discharge flow path; and a leak determination section for determining fluid leakage, wherein the leakage determination section detects part of the fluid supplied to the switching valve to the discharge flow path. an internal leakage determination process for determining the presence or absence of internal leakage due to leakage and the presence or absence of internal leakage due to leakage of part of the fluid supplied to the pressure action chamber to the discharge flow path; Presence or absence of external leakage caused by part of the fluid flowing through the flow path leaking to the outside, and part of the fluid flowing through the pipe connecting the switching valve and the fluid pressure cylinder leaking to the outside an external leak determination process for determining whether or not there is an external leak, and in the internal leak determination process, if the pressure sensor does not detect the pressure and the discharge side flow rate sensor does not detect the flow rate, the internal leak determination process is performed. is not detected, the pressure sensor detects no pressure, and the discharge-side flow sensor detects a flow rate, it is determined that there is an internal leak, and in the external leak determination process calculating the integrated supply flow rate of the fluid supplied to the pressure action chamber based on the flow rate detected by the supply side flow rate sensor, and calculating the integrated supply flow rate of the fluid supplied to the pressure action chamber based on the flow rate detected by the discharge side flow rate sensor; calculating an integrated discharge flow rate of the discharged fluid, and determining that there is no external leakage when the integrated supply flow rate and the integrated discharge flow rate are the same, and determining that the integrated supply flow rate is greater than the integrated discharge flow rate; is also large, it is determined that the external leakage is present.

A fluid flow path switching device for solving the above problems switches flow paths so that fluid is supplied to one pressure action chamber of a fluid pressure cylinder and fluid is discharged from the other pressure action chamber of the fluid pressure cylinder. a switching valve, a supply channel that supplies fluid to the switching valve, a discharge channel that discharges the fluid from the switching valve to the outside, and a supply-side flow sensor that detects the flow rate of the fluid flowing through the supply channel a discharge side flow rate sensor for detecting the flow rate of the fluid flowing through the discharge channel; a pressure sensor for detecting the pressure of the discharge channel; Presence or absence of internal leakage due to leakage of part of the fluid supplied to the switching valve to the discharge channel, and whether part of the fluid supplied to the pressure action chamber leaks to the discharge channel an internal leakage determination process for determining the presence or absence of an internal leakage caused by the liquid pressure cylinder, the presence or absence of an external leakage caused by a part of the fluid flowing through the supply flow path leaking to the outside, and the switching valve and the fluid pressure cylinder external leakage determination processing for determining the presence or absence of external leakage due to leakage of part of the fluid flowing through the piping connecting the internal leakage determination processing, wherein the pressure is detected by the pressure sensor in the internal leakage determination processing If no flow rate is detected by the discharge side flow rate sensor, it is determined that there is no internal leakage, and if pressure is not detected by the pressure sensor and flow rate is detected by the discharge side flow rate sensor and determining that the internal leakage is present, and in the external leakage determination processing, calculating an integrated supply flow rate of the fluid supplied to the one pressure action chamber based on the flow rate detected by the supply side flow rate sensor. At the same time, the integrated discharge flow rate of the fluid discharged from the other pressure action chamber is calculated based on the flow rate detected by the discharge side flow sensor, and the flow rate difference between the integrated supply flow rate and the integrated discharge flow rate is determined in advance. If it is the value, it is determined that there is no external leakage, and if the flow rate difference between the integrated supply flow rate and the integrated discharge flow rate is larger than a predetermined value, it is determined that the external leakage is present. I judge.

The above-described fluid flow path switching device includes a supply/discharge block in which a part of the supply flow path and a part of the discharge flow path are formed, and a plurality of the switching valves are arranged in parallel with respect to the supply/discharge block. Preferably, the supply-side flow rate sensor, the discharge-side flow rate sensor, and the pressure sensor are integrated with the supply/discharge block.

The above-described fluid flow path switching device includes a manifold base on which part of the supply flow path and part of the discharge flow path are formed, the switching valve is mounted on the manifold base, and the The supply-side flow sensor, the discharge-side flow sensor, and the pressure sensor may be integrated with the manifold base.

In the above fluid flow path switching device, the supply flow path has a main supply flow path and a sub-supply flow path branching from the main supply flow path and bypassing a part of the main supply flow path, A cross-sectional area of the sub-supply channel may be smaller than a cross-sectional area of the main supply channel, and the supply-side flow rate sensor may be provided in the sub-supply channel.

In the above fluid flow path switching device, the discharge flow path has a main discharge flow path and a sub-discharge flow path branching from the main discharge flow path and bypassing a part of the main discharge flow path, A cross-sectional area of the sub-discharge channel may be smaller than a cross-sectional area of the main discharge channel, and the discharge-side flow rate sensor may be provided in the sub-discharge channel.

In the above fluid flow path switching device, the discharge flow path is provided with a check valve that allows fluid to flow from the switching valve to the outside and blocks fluid flow from the outside to the switching valve. It's good to be

According to the present invention, it is possible to determine whether the fluid leakage is an internal leak or an external leak.

FIG. 3 is a diagram for explaining a fluid flow path switching device according to the embodiment; FIG. 5 is a diagram for explaining internal leak determination processing; FIG. 5 is a diagram for explaining internal leak determination processing; FIG. 5 is a diagram for explaining internal leak determination processing; FIG. 5 is a diagram for explaining internal leak determination processing; 4 is a time chart for explaining internal leak determination processing; FIG. 5 is a diagram for explaining external leakage determination processing; FIG. 5 is a diagram for explaining external leakage determination processing; 4 is a time chart for explaining external leak determination processing; FIG. 4 is a diagram for explaining a fluid flow path switching device according to another embodiment;

An embodiment of a fluid flow switching device will be described below with reference to FIGS. 1 to 9. FIG.
As shown in FIG. 1 , the fluid flow switching device 10 includes a supply/discharge block 11 , a plurality of manifold bases 21 and a plurality of switching valves 30 . A plurality of manifold bases 21 are arranged side by side with respect to the supply/exhaust block 11 . Each switching valve 30 is mounted on each manifold base 21 . Therefore, each switching valve 30 is mounted on each manifold base 21 . A plurality of switching valves 30 are arranged in parallel with respect to the supply/discharge block 11 .

Each switching valve 30 has a supply port, a first output port, a second output port, a first discharge port, and a second discharge port. It is a known 5-port solenoid valve that switches communication between ports. A packing is attached to the valve body to seal between the ports. Each switching valve 30 switches the communication between the ports according to the switching position of the valve body, thereby supplying fluid to one pressure action chamber 41 and the other pressure action chamber 42 of each fluid pressure cylinder 40. Switch the flow path for drainage. Each switching valve 30 of this embodiment has a flow path such that fluid is supplied to one pressure action chamber 41 of the fluid pressure cylinder 40 and fluid is discharged from the other pressure action chamber 42 of the fluid pressure cylinder 40 . switch. Each switching valve 30 switches the flow path so that the fluid is supplied to the other pressure action chamber 42 of the fluid pressure cylinder 40 and the fluid is discharged from the one pressure action chamber 41 of the fluid pressure cylinder 40 .

Each hydraulic cylinder 40 includes a cylinder tube 43 , a piston 44 housed within the cylinder tube 43 , and a piston rod 45 attached to the piston 44 . The inside of the cylinder tube 43 is partitioned into a pressure action chamber 41 on one side and a pressure action chamber 42 on the other side by a piston 44 . A packing (not shown) attached to the piston 44 seals between the one pressure action chamber 41 and the other pressure action chamber 42 .

The piston rod 45 moves integrally with the piston 44 as the piston 44 reciprocates. The piston rod 45 can pass through the other pressure action chamber 42 and retract into and out of the cylinder tube 43 . The maximum volume of the other pressure action chamber 42 is smaller than the maximum volume of the one pressure action chamber 41 by the amount that the piston rod 45 passes through. Therefore, the maximum volume of one pressure action chamber 41 is larger than the maximum volume of the other pressure action chamber 42 .

The supply/discharge block 11 has a first centralized supply port 12a and a second centralized supply port 12b. In addition, the supply/discharge block 11 has a centralized supply channel 13 . The centralized supply channel 13 has a main centralized supply channel 13a and a sub-concentrated supply channel 13b that branches from the main centralized supply channel 13a and bypasses part of the main centralized supply channel 13a. . One end of the main centralized supply channel 13a is connected to the first centralized supply port 12a. The other end of the main centralized supply channel 13a is connected to the second centralized supply port 12b. The channel cross-sectional area of the sub-centralized supply channel 13b is smaller than the channel cross-sectional area of the main centralized supply channel 13a. The first centralized supply port 12 a is connected to a fluid pressure device 15 via an external supply flow path 14 . The external supply channel 14 is, for example, piping.

The supply/discharge block 11 has a first centralized discharge port 16a, a second centralized discharge port 16b, and a centralized external discharge port 16c. In addition, the supply/discharge block 11 has a concentrated discharge channel 17 . The concentrated discharge channel 17 has a main concentrated discharge channel 17a and a sub-concentrated discharge channel 17b that branches from the main concentrated discharge channel 17a and bypasses part of the main concentrated discharge channel 17a. . One end of the main concentrated discharge channel 17a is connected to a first branched connection channel 171a connected to the first concentrated discharge port 16a and a second branched connection channel 172a connected to the second concentrated discharge port 16b. branched. The other end of the main centralized discharge channel 17a is connected to the centralized external discharge port 16c. The channel cross-sectional area of the sub-concentrated discharge channel 17b is smaller than the channel cross-sectional area of the main concentrated discharge channel 17a. The centralized external discharge port 16c is connected to the outside via an external discharge channel 18 . The external discharge channel 18 is, for example, piping.

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

Among the plurality of manifold bases 21 arranged side by side with respect to the supply/discharge block 11 , the base supply channel 22 of the manifold base 21 arranged closest to the supply/discharge block 11 is located at the second concentration of the supply/discharge block 11 . It is connected to the supply port 12b. The base supply channels 22 of adjacent manifold bases 21 communicate with each other. Therefore, the base supply channel 22 of each manifold base 21 is connected to the second centralized supply port 12b of the supply/discharge block 11 .

Then, the fluid compressed by the fluid pressure device 15 passes through the external supply channel 14, the first centralized supply port 12a, the centralized supply channel 13, the second centralized supply port 12b, and each base supply channel 22. It is supplied to the switching valve 30 . Therefore, the external supply channel 14, the first centralized supply port 12a, the centralized supply channel 13, the second centralized supply port 12b, and each base supply channel 22 are connected to the supply channel 27 that supplies fluid to each switching valve 30. constitutes A part of the supply channel 27 is formed in the supply/discharge block 11 . A part of the supply channel 27 is formed in each manifold base 21 . The supply channel 27 has the main centralized supply channel 13a as a main supply channel, and the sub-concentrated supply channel 13b branches from the main supply channel and bypasses part of the main supply channel. I have it as a road.

Among the plurality of manifold bases 21 arranged side by side with respect to the supply/discharge block 11 , the first base discharge channel 25 of the manifold base 21 arranged closest to the supply/discharge block 11 is the first base discharge channel 25 of the supply/discharge block 11 . 1 centralized discharge port 16a. The first base discharge passages 25 of adjacent manifold bases 21 communicate with each other. Therefore, each first base discharge passage 25 of each manifold base 21 is connected to the first concentrated discharge port 16 a of the supply/discharge block 11 .

Among the plurality of manifold bases 21 arranged side by side with respect to the supply/discharge block 11 , the second base discharge channel 26 of the manifold base 21 arranged closest to the supply/discharge block 11 is the second base discharge channel 26 of the supply/discharge block 11 . 2 centralized discharge port 16b. The second base discharge channels 26 of adjacent manifold bases 21 communicate with each other. Therefore, each second base discharge passage 26 of each manifold base 21 is connected to the second concentrated discharge port 16 b of the supply/discharge block 11 .

Then, for example, the fluid discharged from each switching valve 30 to each first base discharge channel 25 passes through each first base discharge channel 25, first centralized discharge port 16a, centralized discharge channel 17, and centralized external discharge port. 16c and an external discharge channel 18 to the outside. In addition, for example, the fluid discharged from each switching valve 30 to each second base discharge flow path 26 flows through each second base discharge flow path 26, second concentrated discharge port 16b, concentrated discharge flow path 17, and concentrated external discharge port. 16c and an external discharge channel 18 to the outside. Thus, each first base discharge channel 25, first centralized discharge port 16a, each second base discharge channel 26, second centralized discharge port 16b, centralized discharge channel 17, centralized external discharge port 16c, and external discharge flow The passage 18 constitutes a discharge passage 28 for discharging the fluid from each switching valve 30 to the outside. A part of the discharge passage 28 is formed in the supply/discharge block 11 . A part of the discharge channel 28 is formed in each manifold base 21 . The discharge channel 28 has a main concentrated discharge channel 17a as a main discharge channel, and a sub-concentrated discharge channel 17b that branches off from the main discharge channel and bypasses part of the main discharge channel. I have it as a road.

The external discharge channel 18 is provided with a check valve 18a. The check valve 18a allows fluid to flow from the centralized external discharge port 16c to the outside via the external discharge channel 18, and allows fluid to flow from the outside to the centralized external discharge port 16c via the external discharge channel 18. Block the flow. Therefore, the check valve 18a allows the flow of fluid from the switching valve 30 to the outside and blocks the flow of fluid to the switching valve 30 from the outside.

The first base output channel 23 of each manifold base 21 is connected to one pressure action chamber 41 of each fluid pressure cylinder 40 via each first external output channel 46 . Each first external output channel 46 is, for example, a pipe. Also, the second base output channel 24 of each manifold base 21 is connected to the other pressure action chamber 42 of each fluid pressure cylinder 40 via each second external output channel 47 . Each second external output channel 47 is, for example, a pipe.

For example, when the solenoid of the switching valve 30 is energized, the valve body of the switching valve 30 moves between the supply port and the first output port, and between the second output port and the second discharge port. 1 switching position. When the valve body of the switching valve 30 switches to the first switching position, the packing of the valve body seals between the supply port and the second output port and between the first output port and the first discharge port. .

The fluid output from the switching valve 30 through the first output port to the first base output flow path 23 is supplied through the first external output flow path 46 to one pressure action chamber 41 of the fluid pressure cylinder 40. , and the piston 44 of the fluid pressure cylinder 40 moves so that the volume of one pressure action chamber 41 increases. As a result, the volume of the other pressure action chamber 42 decreases, and the fluid in the other pressure action chamber 42 of the fluid pressure cylinder 40 flows through the second external output flow path 47, the second output port, and the second discharge port. and is discharged to the second base discharge channel 26 .

For example, when the solenoid of the switching valve 30 is de-energized, the valve body of the switching valve 30 moves between the supply port and the second output port and between the first output port and the first discharge port. 2 switches to the switching position. When the valve body of the switching valve 30 switches to the second switching position, the packing of the valve body seals between the supply port and the first output port and between the second output port and the second discharge port. .

The fluid output from the switching valve 30 to the second base output flow path 24 via the second output port is supplied to the other pressure action chamber 42 of the fluid pressure cylinder 40 via the second external output flow path 47. , and the piston 44 of the fluid pressure cylinder 40 moves so that the volume of the other pressure action chamber 42 increases. As a result, the volume of one pressure action chamber 41 decreases, and the fluid in one pressure action chamber 41 of the fluid pressure cylinder 40 flows through the first external output flow path 46, the first output port, and the first discharge port. and is discharged to the first base discharge channel 25 .

The fluid flow switching device 10 includes a microcomputer 50 (MPU). The microcomputer 50 is built in the supply/exhaust 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 rate sensor 61 . The supply-side flow rate sensor 61 is provided in the sub-concentrated supply channel 13 b of the centralized supply channel 13 . The supply-side flow rate sensor 61 detects the flow rate of fluid flowing through the sub-concentrated supply flow path 13b. Therefore, the supply-side flow rate sensor 61 detects the flow rate of the fluid flowing through the supply channel 27 . The supply-side flow rate sensor 61 is built in the supply/discharge block 11 . Therefore, the supply-side flow rate sensor 61 is integrated with the supply/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 transmitted 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 channel 17 b of the concentrated discharge channel 17 . The discharge-side flow rate sensor 62 detects the flow rate of the fluid flowing through the sub-concentrated discharge channel 17b. Therefore, the discharge side flow rate sensor 62 detects the flow rate of the fluid flowing through the discharge channel 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 rate sensor 62 is electrically connected to the microcomputer 50 . Information on the flow rate detected by the discharge-side flow rate sensor 62 is transmitted to the microcomputer 50 .

The discharge channel 28 has a pressure detection channel 19 . The pressure detection channel 19 is formed in the supply/discharge block 11 . The pressure detection channel 19 branches off from a part of the main concentrated discharge channel 17a closer to one end than the sub-concentrated discharge channel 17b.

The fluid flow switching device 10 has a pressure sensor 63 . A pressure sensor 63 is provided in the pressure detection channel 19 . A pressure sensor 63 detects the pressure in the pressure detection channel 19 . Therefore, the pressure sensor 63 detects the pressure in the discharge channel 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 about the pressure detected by the pressure sensor 63 is transmitted to the microcomputer 50 .

The microcomputer 50 pre-stores a program for determining whether or not the movement of the piston 44 of the fluid pressure cylinder 40 is in a transitional state based on changes in the pressure in the discharge passage 28 detected by the pressure sensor 63 . For example, when pressure is detected by the pressure sensor 63, the microcomputer 50 determines that the movement of the piston 44 of the fluid pressure cylinder 40 is in a transient state. On the other hand, if no pressure is detected by the pressure sensor 63, the microcomputer 50 determines that the piston 44 of the fluid pressure cylinder 40 has reached the stroke end and is stopped.

The microcomputer 50 pre-stores a program for executing 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. Therefore, the microcomputer 50 functions as a leak determination section that determines fluid leakage.

Here, "internal leakage" means that part of the fluid supplied from the supply passage 27 to the switching valve 30 leaks into the pressure action chamber of the fluid pressure cylinder 40 due to deterioration of the packing of the valve body of the switching valve 30, for example. It means leaking to the discharge channel 28 without being supplied to 41 and 42 . Further, the term "internal leakage" refers to, for example, deterioration of the packing of the piston 44 of the fluid pressure cylinder 40, causing part of the fluid supplied to one pressure action chamber 41 to leak to the other pressure action chamber 42. , part of the fluid supplied to the other pressure action chamber 42 leaks to the one pressure action chamber 41 .

On the other hand, "external leakage" refers to, for example, leakage of part of the fluid flowing through the supply channel 27 to the outside due to a seal failure between the supply channel 27 and the switching valve 30, It means that part of the fluid flowing through the pipe leaks to the outside due to a seal failure of the pipe connecting the fluid pressure cylinder 40 .

The microcomputer 50 preliminarily stores a program for determining that there is no internal leakage when pressure is not detected by the pressure sensor 63 and flow rate is not detected by the discharge-side flow rate sensor 62 in the internal leakage determination process. . The microcomputer 50 stores in advance a program for judging that there is an internal leak when the pressure sensor 63 detects no pressure and the discharge-side flow rate sensor 62 detects a flow rate in the internal leak determination process. It is

As the pressure sensor 63 of the present embodiment, for example, a sensor that cannot detect minute changes in the pressure of the discharge channel 28 when fluid is leaking to the discharge channel 28 due to internal leakage is adopted. ing.

The microcomputer 50 stores in advance a program that does not execute internal leakage determination processing when the pressure is detected by the pressure sensor 63 and the movement of the piston 44 of the fluid pressure cylinder 40 is determined to be in a transient state. there is Further, the microcomputer 50 has a program for executing internal leakage determination processing when it is determined that the pressure sensor 63 does not detect the pressure and the piston 44 of the fluid pressure cylinder 40 is stopped. stored in advance.

The microcomputer 50 pre-stores a program for storing the flow rate detected by the discharge-side flow rate sensor 62 as an internal leak amount when it is determined that there is an internal leak in the internal leak determination process.

In the external leakage determination process, the microcomputer 50 calculates the integrated supply flow rate of the fluid supplied to one pressure action chamber 41 based on the flow rate detected by the supply side flow rate sensor 61, and the discharge side flow rate sensor 62 A program is stored in advance for calculating the integrated discharge flow rate of the fluid discharged from one of the pressure action chambers 41 based on the detected flow rate. The microcomputer 50 determines that there is no external leakage when the integrated supply flow rate and the integrated discharge flow rate are the same, and determines that there is external leakage when the integrated supply flow rate is greater than the integrated discharge flow rate. A judgment program for judging is stored in advance.

Specifically, in the external leakage determination process, the microcomputer 50 turns on the power to the solenoid of the switching valve 30, and then, based on the flow rate detected by the supply-side flow rate sensor 61, the pressure action chamber 41 is operated. A program for calculating the integrated supply flow rate of the fluid to be supplied is stored in advance. In addition, in the external leakage determination process, the microcomputer 50 turns off the power to the solenoid of the switching valve 30, and then discharges from one pressure action chamber 41 based on the flow rate detected by the discharge side flow rate sensor 62. A program for calculating the integrated discharge flow rate of the fluid is stored in advance. The microcomputer 50 stores the calculated integrated supply flow rate and integrated discharge flow rate, respectively. In the external leakage determination process, the microcomputer 50 stores the integrated supply flow rate of the fluid supplied to one pressure action chamber 41 after turning on the energization of the solenoid of the switching valve 30 and the energization of the solenoid of the switching valve 30. A program is stored in advance for comparing the accumulated discharge flow rate of the fluid discharged from one of the pressure action chambers 41 after the switch is turned off. The microcomputer 50 pre-stores a program for determining that there is no external leakage when the integrated supply flow rate and the integrated discharge flow rate are the same in the compared integrated supply flow rate and integrated discharge flow rate. On the other hand, the microcomputer 50 pre-stores a program for judging that there is an external leakage when the integrated supply flow rate and the integrated discharge flow rate are larger than the integrated discharge flow rate.

In addition, in the external leakage determination process, the microcomputer 50 calculates the integrated supply flow rate of the fluid supplied to the other pressure action chamber 42 based on the flow rate detected by the supply side flow rate sensor 61, and the discharge side flow rate sensor A program is stored in advance for calculating the integrated discharge flow rate of the fluid discharged from the other pressure action chamber 42 based on the flow rate detected by 62 . The microcomputer 50 determines that there is no external leakage when the integrated supply flow rate and the integrated discharge flow rate are the same, and determines that there is external leakage when the integrated supply flow rate is greater than the integrated discharge flow rate. A judgment program for judging is stored in advance.

Specifically, in the external leakage determination process, the microcomputer 50 turns off power to the solenoid of the switching valve 30, and then, based on the flow rate detected by the supply-side flow rate sensor 61, the other pressure action chamber 42 is operated. A program for calculating the integrated supply flow rate of the fluid to be supplied is stored in advance. In addition, in the external leakage determination process, the microcomputer 50 turns on power to the solenoid of the switching valve 30, and then discharges the gas from the other pressure action chamber 42 based on the flow rate detected by the discharge side flow rate sensor 62. A program for calculating the integrated discharge flow rate of the fluid is stored in advance. The microcomputer 50 stores the calculated integrated supply flow rate and integrated discharge flow rate, respectively. In the external leakage determination process, the microcomputer 50 detects the integrated supply flow rate of the fluid supplied to the other pressure action chamber 42 after turning off the power supply to the solenoid of the switching valve 30 and the power supply to the solenoid of the switching valve 30. A program is stored in advance for comparing the accumulated discharge flow rate of the fluid discharged from the other pressure action chamber 42 after it is turned on. The microcomputer 50 pre-stores a program for determining that there is no external leakage when the integrated supply flow rate and the integrated discharge flow rate are the same in the compared integrated supply flow rate and integrated discharge flow rate. On the other hand, the microcomputer 50 pre-stores a program for judging that there is an external leakage when the integrated supply flow rate and the integrated discharge flow rate are larger than the integrated discharge flow rate.

A program is stored in advance in the microcomputer 50 so that the external leak determination process is always executed regardless of whether or not the pressure sensor 63 detects. Therefore, the microcomputer 50 always executes the external leakage determination process even if the movement of the piston 44 of the fluid pressure cylinder 40 is in a transient state or the piston 44 of the fluid pressure cylinder 40 is stopped. ing.

In the microcomputer 50, 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 compared in the external leak determination process is calculated, and the calculated flow rate is used as an external leak. A program for storing the quantity is stored in advance.

Next, the operation of this embodiment will be described.
In addition, in the following explanation of the operation, only the operation related to one set of the switching valve 30 and the fluid pressure cylinder 40 will be explained in order to simplify the explanation. 2 and subsequent drawings, the illustration of the supply channel 27 and the discharge channel 28 is simplified.

First, in the microcomputer 50, how to determine the presence or absence of internal leakage will be described together with the operation of the present embodiment.
As shown in FIG. 2, for example, when the solenoid of the switching valve 30 is de-energized, the switching valve 30 is switched from the first switching position to the second switching position. Then, the fluid in one pressure action chamber 41 passes through the discharge channel 28 and is discharged to the outside, and the fluid that has passed through the supply channel 27 is supplied to the other pressure action chamber 42, causing the piston rod 45 to move to the cylinder. The tube 43 is in the most immersed state.

As shown in FIG. 3, when the solenoid of the switching valve 30 is energized, the switching valve 30 is switched from the second switching position to the first switching position. Then, the fluid that has passed through the supply channel 27 is supplied to one pressure action chamber 41, and the fluid in the other pressure action chamber 42 passes through the discharge channel 28 and is discharged to the outside. The amount of protrusion with respect to the tube 43 gradually increases.

At this time, since pressure is detected by the pressure sensor 63, the microcomputer 50 determines that the movement of the piston 44 of the fluid pressure cylinder 40 is in a transient state. Therefore, the microcomputer 50 does not execute internal leakage determination processing.

As shown in FIG. 4, when the piston rod 45 protrudes most from the cylinder tube 43, the piston 44 of the fluid pressure cylinder 40 reaches the stroke end and 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 stopped, and executes internal leakage determination processing.

Here, if the pressure sensor 63 does not detect the pressure and the discharge-side flow rate sensor 62 does not detect the flow rate in the internal leak determination process, the microcomputer 50 determines that there is no internal leakage.

As shown in FIG. 5, the microcomputer 50 determines that there is an internal leak when the pressure sensor 63 detects no pressure and the discharge-side flow rate sensor 62 detects a flow rate in the internal leak determination process. . That is, even though the piston 44 of the fluid pressure cylinder 40 is stopped, part of the fluid supplied from the supply passage 27 to the switching valve 30 is lost due to, for example, deterioration of the packing of the valve body of the switching valve 30. , it is assumed that the fluid is not supplied to one of the pressure action chambers 41 of the fluid pressure cylinder 40 and leaks to the discharge passage 28 . In addition, even though the piston 44 of the fluid pressure cylinder 40 is stopped, for example, due to deterioration of the packing of the piston 44 of the fluid pressure cylinder 40, part of the fluid in one pressure action chamber 41 is affected by the pressure of the other pressure action chamber 41. It is assumed that it has leaked into chamber 42 and out of the other pressure action chamber 42 into discharge channel 28 . Therefore, it is assumed that an internal leak has occurred.

As shown in FIG. 6, the microcomputer 50 stores the flow rate Qx detected by the discharge-side flow rate sensor 62 as an internal leakage amount when it is determined that there is an internal leakage in the internal leakage determination process. The microcomputer 50 then 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 notifies the operator of the abnormality by receiving the flow rate Qx as the internal leakage amount.

Next, how the microcomputer 50 determines the presence or absence of external leakage will be described together with the operation of the present embodiment.
As shown in FIG. 7, for example, when the solenoid of the switching valve 30 is energized, the switching valve 30 is switched to the first switching position, and the fluid that has passed through the supply passage 27 flows into one of the pressure action chambers 41. While being supplied, the fluid in the other pressure action chamber 42 passes through the discharge passage 28 and is discharged to the outside. As a result, the piston rod 45 protrudes most from the cylinder tube 43 .

At this time, the microcomputer 50 calculates the integrated supply flow rate of the fluid supplied to one pressure action chamber 41 based on the flow rate detected by the supply-side flow rate sensor 61 in the external leakage determination process. In addition, the microcomputer 50 calculates the integrated discharge flow rate of the fluid discharged from the other pressure action 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 turns on the energization of the solenoid of the switching valve 30, and calculates the integrated supply flow rate of the fluid supplied to one pressure action chamber 41 and the fluid discharged from the other pressure action chamber 42. Calculate the integrated discharge flow rate of each. Then, the microcomputer 50 stores the calculated cumulative supply flow rate and cumulative discharge flow rate, respectively.

As shown in FIG. 8, when the solenoid of the switching valve 30 is de-energized, the switching valve 30 is switched from the first switching position to the second switching position, and the fluid in one pressure action chamber 41 is discharged through the discharge passage 28. , and is discharged to the outside, and the fluid that has passed through the supply flow path 27 is supplied to the other pressure action chamber 42 . As a result, the piston rod 45 is most retracted into the cylinder tube 43 .

At this time, the microcomputer 50 calculates the integrated supply flow rate of the fluid supplied to the other pressure action chamber 42 based on the flow rate detected by the supply side flow rate sensor 61 in the external leakage determination process. Further, in the external leakage determination process, the microcomputer 50 calculates the integrated discharge flow rate of the fluid discharged from one pressure action chamber 41 based on the flow rate detected by the discharge side flow sensor 62 . In this way, the microcomputer 50 turns off the power supply to the solenoid of the switching valve 30, and then determines the integrated supply flow rate of the fluid supplied to the other pressure action chamber 42 and the fluid discharged from the one pressure action chamber 41. Calculate the integrated discharge flow rate of each. Then, the microcomputer 50 stores the calculated cumulative supply flow rate and cumulative discharge flow rate, respectively.

As shown in FIG. 9, in the external leakage determination process, the microcomputer 50, for example, turns on the solenoid of the switching valve 30 and then the integrated supply flow rate of the fluid supplied to one of the pressure action chambers 41 and the switching After the solenoid of the valve 30 is de-energized, it is compared with the integrated discharge flow rate of the fluid discharged from one of the pressure action chambers 41 . Then, the microcomputer 50 determines that there is no external leakage when the integrated supply flow rate and the integrated exhaust flow rate are the same in the compared integrated supply flow rate and integrated exhaust flow rate. On the other hand, the microcomputer 50 determines that there is an external leakage when the integrated supply flow rate is greater than the integrated discharge flow rate, as indicated by the two-dot chain line in FIG. .

In the external leakage determination process, the microcomputer 50, for example, turns off the energization of the solenoid of the switching valve 30 and calculates the integrated supply flow rate of the fluid supplied to the other pressure action chamber 42 and the energization of the solenoid of the switching valve 30. is turned on, and the integrated discharge flow rate of the fluid discharged from the other pressure action chamber 42 is compared. Then, the microcomputer 50 determines that there is no external leakage when the integrated supply flow rate and the integrated exhaust flow rate are the same in the compared integrated supply flow rate and integrated exhaust flow rate. On the other hand, the microcomputer 50 determines that there is external leakage when the integrated supply flow rate is greater than the integrated discharge flow rate, as indicated by the dashed line in FIG. That is, for example, due to poor sealing between the supply channel 27 and the switching valve 30, part of the fluid flowing through the supply channel 27 may leak to the outside, or the switching valve 30 and the fluid pressure cylinder 40 may be connected. It is assumed that a part of the fluid flowing through the pipe is leaking to the outside due to poor sealing of the pipe.

When the microcomputer 50 determines in the external leak determination process that there is an external leak, the microcomputer 50 calculates the difference between the integrated supply flow rate and the integrated exhaust flow rate compared in the external leak determination process, and uses the calculated flow rate as the external leak amount. remember as The microcomputer 50 then transmits the calculated external leakage amount to the external control device 51 . The external control device 51 notifies the operator of the abnormality by receiving the amount of external leakage.

The following effects can be obtained in the above embodiment.
(1) In the internal leak determination process, the microcomputer 50 determines that there is no internal leakage when the pressure sensor 63 detects no pressure and the discharge-side flow sensor 62 detects no flow rate, If the pressure is not detected by , and the flow rate is detected by the discharge-side flow rate sensor 62, it is determined that there is internal leakage. In addition, in the external leakage determination process, the microcomputer 50 calculates the integrated supply flow rate of the fluid supplied to one of the pressure action chambers 41 based on the flow rate detected by the supply side flow rate sensor 61, and calculates the discharge side flow rate. Based on the flow rate detected by the sensor 62, the integrated discharge flow rate of the fluid discharged from one pressure action chamber 41 is calculated. When the integrated supply flow rate and the integrated discharge flow rate are the same, it is determined that there is no external leakage, and when the integrated supply flow rate is greater than the integrated discharge flow rate, it is determined that there is an external leakage. According to this, in the fluid flow path switching device 10, it is possible to determine whether the fluid leak is an internal leak or an external leak.

(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 . According to this, for example, compared with the 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, the entire fluid flow path switching device 10 can be made compact. can be

(3) The channel cross-sectional area of the sub-centralized supply channel 13b is smaller than the channel cross-sectional area of the main centralized supply channel 13a. The supply-side flow rate sensor 61 is provided in the sub-concentrated supply channel 13b. According to this, a small sensor can be adopted as the supply-side flow rate sensor 61, so that the entire fluid flow path switching device 10 can be made compact.

(4) The channel cross-sectional area of the sub-concentrated discharge channel 17b is smaller than the channel cross-sectional area of the main concentrated discharge channel 17a. The discharge-side flow rate sensor 62 is provided in the sub-concentrated discharge channel 17b. According to this, since a small sensor can be adopted as the discharge side flow rate sensor 62, the entire fluid flow path switching device 10 can be made compact.

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

It should be noted that the above embodiment can be implemented with the following modifications. The above embodiments and the following modifications can be combined with each other within a technically consistent range.

In the embodiment, in the external leakage determination process, the microcomputer 50 calculates the integrated supply flow rate of the fluid supplied to one pressure action chamber 41 based on the flow rate detected by the supply side flow rate sensor 61, and calculates the discharge side flow rate. When the integrated discharge flow rate of the fluid discharged from the other pressure action chamber 42 is calculated based on the flow rate detected by the flow sensor 62, and the flow rate difference between the integrated supply flow rate and the integrated discharge flow rate is a predetermined value. , it may be determined that there is no external leakage. Then, the microcomputer 50 may determine that there is external leakage when the flow rate difference between the integrated supply flow rate and the integrated discharge flow rate is greater than a predetermined value.

Specifically, in the external leakage determination process, the microcomputer 50 controls the integrated supply flow rate of the fluid supplied to one pressure action chamber 41 after energization of the solenoid of the switching valve 30 is turned on, The flow rate difference is compared with the integrated discharge flow rate of the fluid discharged from 42 . Then, the microcomputer 50 determines that there is no external leakage when the flow rate difference between the integrated supply flow rate and the integrated discharge flow rate is a predetermined value in the compared integrated supply flow rate and integrated discharge flow rate. On the other hand, the microcomputer 50 determines that there is an external leakage when the flow rate difference between the integrated supply flow rate and the integrated discharge flow rate is larger than a predetermined value in the compared integrated supply flow rate and integrated discharge flow rate. According to this, even if the maximum volume of one pressure action chamber 41 and the maximum volume of the other pressure action chamber 42 are different, the integrated supply flow rate of one pressure action chamber 41 and the other pressure action chamber 42 at the same timing. Since external leakage can be determined using the integrated discharge flow rate of the pressure action chamber 42, external leakage can be determined efficiently.

- 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 each manifold base 21 . In this case, each supply-side flow rate sensor 61 is provided in the base supply channel 22 of each manifold base 21 . Each discharge side flow rate sensor 62 and each pressure sensor 63 are provided in the first base discharge channel 25 and the second base discharge channel 26 of each manifold base 21, respectively. According to this, it is possible to determine which manifold base 21 is leaking fluid, and furthermore, whether the leakage of fluid from the manifold base 21 in which the fluid is leaking is an internal leak or an external leak. can be determined.

- In an embodiment, the supply side flow rate sensor 61 may be provided in the main centralized supply flow path 13a, for example. In this case, the centralized supply channel 13 may be configured without the sub-concentrated supply channel 13b.

- In an embodiment, the discharge side flow rate sensor 62 may be provided, for example, in the main concentrated discharge channel 17a. In this case, the concentrated discharge channel 17 may be configured without the sub-concentrated discharge channel 17b.

- In the embodiment, the fluid flow path switching device 10 may have a configuration in which the external discharge flow path 18 is not provided with the check valve 18a.
- In an embodiment, each switching valve 30 may be a 3-port solenoid valve. In this case, each switching valve 30 switches the flow path to supply and discharge the fluid only to one pressure action chamber 41 of each fluid pressure cylinder 40 . In this case, therefore, each hydraulic cylinder 40 is a spring-loaded, single-acting cylinder.

10... Fluid channel switching device 11... Supply/discharge block 13a... Main centralized supply channel as main supply channel 13b... Sub-concentrated supply channel as sub-supply channel 17a... Main discharge channel Main concentrated discharge channel 17b Sub-concentrated discharge channel as sub-discharge channel 18a Check valve 21 Manifold base 27 Supply channel 28 Discharge channel 30 Switching valve 40 Fluid pressure cylinder 41 One pressure action chamber 42 The other pressure action chamber 50 A microcomputer functioning as a leak determination unit 61 Supply side flow sensor 62 Discharge side flow sensor 63 Pressure sensor.

Claims (7)

a switching valve for switching a flow path for supplying and discharging fluid to and from the pressure action chamber of the fluid pressure cylinder;
a supply channel for supplying fluid to the switching valve;
a discharge channel for discharging the fluid from the switching valve to the outside;
a supply-side flow rate sensor that detects the flow rate of the fluid flowing through the supply channel;
a discharge-side flow rate sensor that detects the flow rate of the fluid flowing through the discharge channel;
a pressure sensor that detects the pressure of the discharge channel;
a leakage determination unit that determines fluid leakage,
The leakage determination unit determines whether or not there is internal leakage due to leakage of part of the fluid supplied to the switching valve to the discharge passage, and whether part of the fluid supplied to the pressure action chamber is discharged. Internal leakage determination processing for determining the presence or absence of internal leakage caused by leakage to the flow path , presence or absence of external leakage caused by leakage of part of the fluid flowing through the supply flow path to the outside, and the switching valve an external leakage determination process for determining the presence or absence of external leakage caused by part of the fluid flowing through the pipe connecting the fluid pressure cylinder leaking to the outside ,
In the internal leakage determination process, if the pressure sensor does not detect the pressure and the discharge side flow sensor does not detect the flow rate, it is determined that there is no internal leakage, and the pressure sensor detects the pressure. and if the flow rate is detected by the discharge side flow rate sensor, it is determined that the internal leakage is present,
In the external leakage determination process, an integrated supply flow rate of the fluid supplied to the pressure action chamber is calculated based on the flow rate detected by the supply side flow rate sensor, and based on the flow rate detected by the discharge side flow rate sensor. to calculate the integrated discharge flow rate of the fluid discharged from the pressure action chamber, and when the integrated supply flow rate and the integrated discharge flow rate are the same, it is determined that there is no external leakage, and the integrated supply flow rate is is greater than the integrated discharge flow rate, the fluid flow switching device determines that there is the external leakage. a switching valve for switching a flow path so that fluid is supplied to one pressure action chamber of the fluid pressure cylinder and fluid is discharged from the other pressure action chamber of the fluid pressure cylinder;
a supply channel for supplying fluid to the switching valve;
a discharge channel for discharging the fluid from the switching valve to the outside;
a supply-side flow rate sensor that detects the flow rate of the fluid flowing through the supply channel;
a discharge-side flow rate sensor that detects the flow rate of the fluid flowing through the discharge channel;
a pressure sensor that detects the pressure of the discharge channel;
a leakage determination unit that determines fluid leakage,
The leakage determination unit determines whether or not there is internal leakage due to leakage of part of the fluid supplied to the switching valve to the discharge passage, and whether part of the fluid supplied to the pressure action chamber is discharged. Internal leakage determination processing for determining the presence or absence of internal leakage caused by leakage to the flow path , presence or absence of external leakage caused by leakage of part of the fluid flowing through the supply flow path to the outside, and the switching valve an external leakage determination process for determining the presence or absence of external leakage caused by part of the fluid flowing through the pipe connecting the fluid pressure cylinder leaking to the outside ,
In the internal leakage determination process, if the pressure sensor does not detect the pressure and the discharge side flow sensor does not detect the flow rate, it is determined that there is no internal leakage, and the pressure sensor detects the pressure. and if the flow rate is detected by the discharge side flow rate sensor, it is determined that the internal leakage is present,
In the external leakage determination process, the integrated supply flow rate of the fluid supplied to the one pressure action chamber is calculated based on the flow rate detected by the supply side flow rate sensor, and the flow rate detected by the discharge side flow rate sensor is calculated. is calculated, and if the difference between the integrated supply flow rate and the integrated discharge flow rate is a predetermined value, there is no external leakage and determining that there is the external leakage when a flow rate difference between the integrated supply flow rate and the integrated discharge flow rate is larger than a predetermined value. a supply/discharge block in which part of the supply channel and part of the discharge channel are formed;
A plurality of switching valves are arranged in parallel with respect to the supply/discharge block,
3. The fluid flow path switching device according to claim 1, wherein the supply side flow rate sensor, the discharge side flow rate sensor, and the pressure sensor are integrated with the supply/discharge block. a manifold base on which part of the supply channel and part of the discharge channel are formed;
The switching valve is mounted on the manifold base,
3. The fluid flow switching device according to claim 1, wherein the supply side flow rate sensor, the discharge side flow rate sensor, and the pressure sensor are integrated with the manifold base. The supply channel has a main supply channel and a sub-supply channel branching from the main supply channel and bypassing a part of the main supply channel,
the channel cross-sectional area of the sub-supply channel is smaller than the channel cross-sectional area of the main supply channel,
The fluid channel switching device according to any one of claims 1 to 4, wherein the supply-side flow rate sensor is provided in the sub-supply channel. The discharge channel has a main discharge channel and a sub-discharge channel branching from the main discharge channel and bypassing a part of the main discharge channel,
a channel cross-sectional area of the sub-discharge channel is smaller than a channel cross-sectional area of the main discharge channel;
The fluid flow path switching device according to any one of claims 1 to 5, wherein the discharge side flow rate sensor is provided in the sub-discharge flow path. Claims 1 to 6, wherein the discharge passage is provided with a check valve that allows fluid to flow from the switching valve to the outside and blocks fluid from flowing from the outside to the switching valve. The fluid flow switching device according to any one of Claims 1 to 3.

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