Fluid leakage detection device

Abstract

To provide a fluid leakage detection device which can identify a portion where fluid leakage occurs.SOLUTION: A fluid leakage detection device 10 according to the disclosure detects leakage of a fluid in a fluid circuit 100 including a fluid supply source SS, valve devices 2, 14, and a drive device 1. The fluid leakage detection device 10 includes: a first pressure sensor 13 provided in a first passage F1 connecting the fluid supply source SS with the valve devices 2, 14; second and third pressure sensors 3, 4 provided at second and third passages F2, F3 connecting the valve devices 2, 14 with the drive device 1; and a control unit 15.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a fluid leak detection device. [Background technology]

[0002] The automatic cooking machine disclosed in Patent Document 1 is equipped with a fluid leakage detection device. The automatic cooking machine disclosed in Patent Document 1 includes an air drive mechanism, piping, an air valve, a pressure sensor, and a display unit. The air drive mechanism includes an air cylinder, and the piping supplies air to the air drive mechanism. The air valve is provided midway through the piping, and the pressure sensor detects the air pressure in the piping from the air valve to the air drive mechanism. The display unit displays abnormal pressure information caused by air leakage when the air pressure detected by the pressure sensor falls below a threshold value. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 09-313143 Summary of the Invention [Problem to be solved by the invention]

[0004] The present inventors have discovered the following technical problems. In such an automatic cooking machine, air leakage is detected when the air pressure falls below a threshold value. When air leaks inside or outside the air cylinder of the air drive mechanism, the air pressure falls below the threshold value. Therefore, it is not possible to detect whether air is leaking inside or outside the air cylinder.

[0005] The present disclosure has been made in consideration of the above-mentioned problems, and provides a fluid leakage detection device that can identify the location where a fluid leakage has occurred. [Means for solving the problem]

[0006] The fluid leakage detection device of the present disclosure is a fluid leakage detection device that detects fluid leakage in a fluid circuit including a fluid supply source, a valve device, and a drive device, and includes a first pressure sensor provided in a first flow path connecting the fluid supply source and the valve device, second and third pressure sensors provided respectively in second and third flow paths connecting the valve device and the drive device, and a control unit. Effect of the Invention

[0007] According to the present disclosure, the location where a fluid leak has occurred can be identified. [Brief description of the drawings]

[0008] [Figure 1] 1A and 1B are a schematic view and an enlarged view showing a configuration example of a fluid leakage detection device according to a first embodiment. [Diagram 2] 5A to 5C are diagrams illustrating an example of an operation of the example configuration of the fluid leakage detection device according to the first embodiment. [Diagram 3] FIG. 4 is a diagram showing a modified example of the fluid leakage detection device according to the first embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, specific embodiments to which the present invention is applied will be described in detail with reference to the drawings. However, the present invention is not limited to the following embodiments. In addition, the following description and drawings are appropriately simplified for clarity of explanation.

[0010] <Embodiment 1> The first embodiment will be described with reference to FIG.

[0011] 1, the fluid leakage detection device 10 includes an electromagnetic valve 12, a fluid supply source side pressure sensor 13 (first pressure sensor), a valve body 14, and a control unit 15. The fluid leakage detection device 10 is provided in a fluid circuit 100, and detects fluid leakage in the fluid circuit 100. The fluid circuit 100 is, for example, a pneumatic circuit, and the fluid in the fluid circuit 100 is air.

[0012] The fluid circuit 100 is configured using a flow path F1 (first flow path), a flow path F2 (second flow path), and a flow path F3 (third flow path). The flow path F1 connects the fluid supply source SS and the valve body 14. The flow paths F2 and F3 connect the valve body 14 and the drive device 1. The flow paths F1, F2, and F3 may be configured, for example, by hoses or the like.

[0013] The fluid supply source SS is a source that supplies a fluid, for example, an air tank supplied with compressed air by an air compressor.

[0014] The driving device 1 includes a cylinder 1a, a rod 1b, a piston 1c, a rod-side hose 1e, and a head-side hose 1f.

[0015] The cylinder 1a is a substantially cylindrical body. The piston 1c is disposed in the cylinder 1a so as to be capable of reciprocating in the longitudinal direction of the cylinder 1a while the end face of the piston 1c slides on the inner peripheral surface of the cylinder 1a. The rod 1b passes from the piston 1c through the head side end of the cylinder 1a and extends outward from the cylinder 1a. The piston 1c divides the interior of the cylinder 1a. The cylinder 1a is connected to a flow path F2 via a rod side hose 1e. The rod side in the cylinder 1a is supplied with fluid from the flow path F2 via the rod side hose 1e, or discharges fluid to the flow path F2. The cylinder 1a is connected to a flow path F3 via a head side hose 1f. The head side in the cylinder 1a is supplied with fluid from the flow path F3 via the head side hose 1f, or discharges fluid to the flow path F3. The piston 1c reciprocates in response to the pressure of the fluid on the head side in the cylinder 1a and the pressure of the fluid on the rod side in the cylinder 1a. The piston 1c supplies a driving force to the outside via the rod 1b.

[0016] The master valve 11, the electromagnetic valve 12, and the fluid supply source side pressure sensor 13 are provided in the flow path F1. The master valve 11, the electromagnetic valve 12, and the fluid supply source side pressure sensor 13 are arranged in this order from the fluid supply source SS to the valve body 14 side.

[0017] The master valve 11 opens or closes the flow path F1 by, for example, being operated by air pressure. The solenoid valve 12 opens or closes the flow path F1 by energizing or deenergizing an electromagnet. The fluid supply source side pressure sensor 13 detects the pressure of the fluid in the flow path F1 and generates a signal indicative of the pressure in the flow path F1.

[0018] The valve body 14 includes the solenoid valve 2, an outlet pressure sensor 3 (second pressure sensor), and a return pressure sensor 4 (third pressure sensor). The solenoid valve 2 and the valve body 14 function as a valve device.

[0019] The solenoid valve 2 is connected to the flow paths F1, F2, and F3. The solenoid valve 2 connects the flow paths F1 and F2 so that the flow paths are connected or can be blocked. The solenoid valve 2 connects the flow paths F1 and F3 so that the flow paths are connected or can be blocked. The solenoid valve 2 opens the flow path F3 to the outside of the valve body 14. The solenoid valve 2 may have, for example, five ports, and the spool may be movable to three positions. The solenoid valve 2 includes, for example, a solenoid and a spool. The solenoid valve 2 moves the spool to a predetermined position in the valve body 14 by energizing the solenoid, etc., and switches the direction in which the fluid in the flow paths F1, F2, and F3 flows when the fluid is connected, blocked, or opened.

[0020] The outlet pressure sensor 3 is provided in the flow path F2. The outlet pressure sensor 3 detects the pressure of the fluid in the flow path F2 and generates a signal indicative of the pressure of the fluid in the flow path F2. The return pressure sensor 4 is provided in the flow path F3. The return pressure sensor 4 detects the pressure of the fluid in the flow path F3 and generates a signal indicative of the pressure of the fluid in the flow path F3.

[0021] The control unit 15 may be configured using a general computer device. The control unit 15 obtains a signal indicating the pressure value of the fluid in the flow path F2 from the outlet pressure sensor 3. The control unit 15 obtains a signal indicating the pressure value of the fluid in the flow path F3 from the return pressure sensor 4. The control unit 15 obtains a signal indicating the pressure value of the fluid in the flow path F1 from the fluid supply source pressure sensor 13. From these, the control unit 15 obtains the pressure values ​​of the fluid in the flow paths F1, F2, and F3. The control unit 15 also sends a signal to the solenoid valve 2 to move the spool in the solenoid valve 2. This allows the flow paths F1 and F2 to communicate with each other or to be blocked off. Also, the flow paths F1 and F3 to communicate with each other or to be blocked off. Also, the flow path F3 is opened to the outside of the valve body 14.

[0022] <Method of detecting fluid leaks> Next, a fluid leakage detection method using the fluid leakage detection device 10 will be described with reference to Figures 1 and 2. Note that the flow paths F1, F2, and F3 shown in Figure 2 and the flow paths F1, F2, and F3 shown in Figure 1 have different connection positions to the solenoid valve 2 in order to show communication and cut-off between the flow paths by the solenoid valve 2, but these have exactly the same hardware configuration.

[0023] First, in steps ST1 and ST2, external leakage is detected from the flow paths F1, F2, and F3 and the drive device 1. After that, in steps ST3 and ST4, internal leakage from the drive device 1 is detected based on the detection results in steps ST1 and ST2.

[0024] 1, the electromagnetic valve 12 closes the flow path F1, and the solenoid valve 2 blocks the flow paths F1 and F2, and blocks the flow paths F1 and F3 (step ST1). In step ST1, the spool position of the solenoid valve 2 is in the closed center.

[0025] Next, the control unit 15 acquires the pressure values ​​of the fluid in the flow paths F1, F2, and F3 from moment to moment, and monitors the decrease in the pressure of the fluid in the flow paths F1, F2, and F3 based on the acquired pressure values ​​of the fluid in the flow paths F1, F2, and F3 (step ST2).

[0026] In step ST2, when the control unit 15 confirms a drop in the fluid pressure in the flow path F1, it determines that a fluid leak has occurred in the flow path F1. When the control unit 15 confirms a drop in the fluid pressure in the flow path F2, it determines that a fluid leak has occurred in the rod side hose 1e, flow path F2, and the rod side of the cylinder 1a. When the control unit 15 confirms a drop in the fluid pressure in the flow path F3, it determines that a fluid leak has occurred in the head side hose 1f, flow path F3, and the head side of the cylinder 1a. This makes it possible to detect an external leak from the drive unit 1.

[0027] In step ST2, if an internal leak in the drive unit 1 occurs, that is, if a fluid leak occurs between the end face of the piston 1c and the inner circumferential surface of the cylinder 1a, the pressure value of the fluid in the flow paths F1, F2, and F3 hardly decreases. Therefore, even if the control unit 15 does not confirm a decrease in the pressure of the fluid in the flow paths F1, F2, and F3 in step ST2, there is a possibility that an internal leak in the drive unit 1 has occurred.

[0028] 2, the solenoid valve 2 connects the flow path F1 and the flow path F2, and opens the flow path F3 to the outside of the valve body 14 (step ST3). The fluids in the flow paths F1 and F2 are integrated. The fluid in the flow path F3 is exhausted to the outside of the valve body 14. If the solenoid valve 2 has a spool, the position of the spool is on the return side in this step ST1.

[0029] Next, the control unit 15 acquires the pressure values ​​of the fluid in the flow paths F1 and F2 from moment to moment, and monitors the decrease in the pressure of the fluid in the flow paths F1 and F2 based on the acquired pressure values ​​of the fluid in the flow paths F1 and F2 (step ST4).

[0030] If the control unit 15 does not detect a decrease in the pressure of the fluid in the flow paths F1 and F2 in step ST2, and detects a decrease in the pressure of the fluid in the flow paths F1 and F2 in step ST4, it determines that a fluid leak has occurred between the end face of the piston 1c and the inner circumferential surface of the cylinder 1a, thereby detecting an internal leak in the drive unit 1.

[0031] From the above, it is possible to detect external and internal leakage from the drive device 1. In other words, it is possible to identify the location where the fluid leakage has occurred.

[0032] <One variation> A fluid leakage detection device 10A shown in FIG.

[0033] The fluid leak detection device 10A detects a fluid leak in a fluid circuit 100A. The fluid circuit 100A includes drive units 1 and 1A. The drive unit 1A has the same configuration as the drive unit 1. The fluid circuit 100A includes drive units 1 and 1A. The fluid circuit 100A may include multiple sets of drive units 1 and 1A, and the example of the fluid circuit 100A shown in FIG. 3 includes three sets of drive units 1 and 1A.

[0034] Except for the valve body and the control unit, the fluid leakage detection device 10A has the same configuration as the fluid leakage detection device 10 shown in Figures 1 and 2. The fluid leakage detection device 10A includes a valve body 14A and a control unit 15A.

[0035] The fluid circuit 100A is configured using a flow path F1A, a flow path F2A, and a flow path F2B. The flow path F1A connects the fluid supply source SS and the valve body 14A. The flow paths F2A and F3A connect the valve body 14 and the drive devices 1 and 1A.

[0036] The valve body 14A includes one or more units each consisting of a solenoid valve 2, an outlet pressure sensor 3, and a return pressure sensor 4. An example of the valve body 14A shown in FIG. 3 includes three units U1, U2, and U3 each consisting of a solenoid valve 2, an outlet pressure sensor 3, and a return pressure sensor 4.

[0037] The control unit 15A obtains a signal indicating the pressure value of the fluid in the flow path F2A from the outlet pressure sensor 3. The control unit 15A obtains a signal indicating the pressure value of the fluid in the flow path F3A from the return pressure sensor 4. The control unit 15A obtains a signal indicating the pressure value of the fluid in the flow path F1A from the fluid supply source pressure sensor 13. From these, the control unit 15A obtains the pressure values ​​of the fluid in the flow paths F1A, F2A, and F3A. The control unit 15A also sends a signal to the solenoid valve 2 to move the spool in the solenoid valve 2. This allows the flow paths F1A and F2A to communicate with each other or to be blocked off. Also, the control unit 15A allows the flow path F1A and F3A to communicate with each other or to be blocked off. Also, the control unit 15A opens the flow path F3A to the outside of the valve body 14.

[0038] In the fluid leakage detection method using the fluid leakage detection device 10A, the above-mentioned steps ST1 to ST4 may be performed in the same manner as in the fluid leakage detection method using the fluid leakage detection device 10 described above. This makes it possible to detect the occurrence of fluid leakage in the fluid circuit 100A including a plurality of drive devices. Also, it is possible to detect the occurrence of fluid leakage in the fluid circuit 100A including two drive devices using one unit. In the fluid leakage detection method using the fluid leakage detection device 10A, the spools of the solenoid valves 2 of the units U1, U2, and U3 move to the positions shown in Table 1 in each cycle. The first cycle corresponds to the above-mentioned steps ST1 and ST2, and the second to fourth cycles correspond to the above-mentioned steps ST3 and ST4. [Table 1]

[0039] The present invention is not limited to the above-mentioned embodiment, and can be modified as appropriate without departing from the spirit of the present invention. The present invention may be implemented by appropriately combining the above-mentioned embodiment and examples thereof. When the fluid circuit 100 shown in FIG. 1 and FIG. 2 includes a plurality of drive devices 1, the valve body 14 may include a plurality of solenoid valves 2 corresponding to the plurality of drive devices 1, respectively. [Explanation of symbols]

[0040] 10, 10A... Fluid leakage detection device 1, 1A... Drive device 1a... Cylinder 1b... Rod 1c... Piston 1e... Rod side hose 1f... Head side hose 2... Solenoid valve 3... Outlet side pressure sensor 4... Return side pressure sensor 11... Master valve 12... Solenoid valve 13... Fluid supply source side pressure sensor 14, 14A... Valve body 15, 15A... Control unit SS... Fluid supply source F1, F1A, F2, F2A, F3, F3A... Flow path

Claims

[Claim 1] A fluid leakage detection device for detecting a fluid leakage in a fluid circuit including a fluid supply source, a valve device, and a drive device, a first pressure sensor provided in a first flow path connecting the fluid supply source and the valve device; The fluid leakage detection device comprises: second and third pressure sensors respectively provided in second and third flow paths connecting the valve device and the drive device; and a control unit.

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