Piping Inspection System

Abstract

To solve a problem that: a coloring agent flows in pneumatic pressure equipment when leakage inspection on piping of a pneumatic pressure equipment system is conducted; and there may be a risk of corrosion or a fault occurring to the pneumatic pressure equipment if the coloring agent is left in the pneumatic pressure equipment.SOLUTION: Leakage inspection on compressed air is performed for an inspected part 32 of piping 16. A piping inspection system 30 has a first branch pipe 34 and a second branch pipe 46. The first branch pipe 34 branches from the piping 16 upstream from the inspected part 32 and joins the piping 16 upstream from the inspected part 32. The second branch pipe 46 branches from the piping 16 downstream from the inspected part 32. The first branch pipe 34 is provided with a fluorescent solvent supply part 40 which supplies a fluorescent solvent 44 to the inspected part. The second branch pipe 46 is provided with a fluorescent solvent collection part 52 which collects the fluorescent solvent from the inspected part.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a piping inspection system that inspects piping through which compressed air flows. [Background technology]

[0002] Pneumatic equipment such as pneumatic cylinders (hereinafter sometimes simply referred to as "equipment") operates by supplying or discharging compressed air. Therefore, if compressed air leaks from the piping connected to the equipment, the equipment will not operate normally. To avoid this, after connecting the equipment to a compressed air supply source via piping, the piping is inspected to determine whether there is a compressed air leak. For example, soapy water is sprayed onto the piping. If there is a compressed air leak, the soapy water will turn into bubbles. An inspector can visually check the bubbles and identify the location of the compressed air leak. However, this inspection requires spraying soapy water over the entire piping. Therefore, the inspection is complicated.

[0003] Therefore, it is conceivable to use a colored test gas, as described in Patent Document 1. The test method described in Patent Document 1 checks whether or not the test gas is leaking from the fuel cell. In this case, a mixture of fluorescent dye and oil (olive oil, etc.) is used as the coloring agent. The mixture is made into a mist and supplied to the fuel cell along with compressed air or hydrogen gas. Light is irradiated onto the fuel cell. In this state, the fuel cell is monitored by a camera.

[0004] If there is a compressed air leak in the fuel cell, a mist will be emitted from the leaking area. At this time, the fluorescent dye in the mist will be highlighted by shining light on it. Therefore, it is easy to capture the fluorescence with a camera. This allows it to be determined that the test gas is leaking from the fuel cell. This test is a visualization test, as it allows visual confirmation of the test gas leak. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 4297862 Summary of the Invention [Problem to be solved by the invention]

[0006] The inspection system described in Patent Document 1 does not have a configuration for removing the coloring agent from the piping. Therefore, when a leak inspection is performed on the piping of a pneumatic equipment system using this inspection system, the coloring agent will flow into the inside of the pneumatic equipment. If the coloring agent remains in the pneumatic equipment, there is a concern that the pneumatic equipment may corrode or malfunction.

[0007] The present invention aims to solve the above-mentioned problems. [Means for solving the problem]

[0008] According to one embodiment of the present invention, there is provided a piping inspection system that inspects whether or not there is a compressed air leak point in an inspected portion of a piping through which compressed air flows, comprising: a first branch pipe that branches off from the pipe upstream of the inspected portion and joins the pipe; a fluorescent solvent supply unit provided in the first branch pipe for supplying a fluorescent solvent to the inspection target portion; a second branch pipe branching from the piping downstream of the inspected portion; a fluorescent solvent recovery unit provided in the second branch pipe for recovering the fluorescent solvent from the inspection target portion; A piping inspection system is provided. [Effects of the Invention]

[0009] According to the present invention, it is possible to easily determine whether a compressed air leak exists in the inspected portion based on whether fluorescence is observed from the inspected portion. In this way, the present invention makes it possible to easily and quickly determine whether a compressed air leak exists. Furthermore, by checking the origin of the fluorescence, it is possible to quickly identify the compressed air leak location. Moreover, the inspector does not need to have any special skills or knowledge to make this determination.

[0010] After flowing through the inspected portion, the fluorescent solvent is recovered by the fluorescent solvent recovery unit. This prevents the fluorescent solvent from flowing downstream of the inspected portion of the piping. That is, the fluorescent solvent is prevented from flowing into pneumatic equipment, etc., connected to the piping. This also prevents the fluorescent solvent from remaining inside the piping or pneumatic equipment. This eliminates concerns about the fluorescent solvent causing damage or corrosion to the pneumatic equipment. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a schematic circuit diagram of a pneumatic equipment system. [Figure 2] FIG. 2 is a schematic circuit diagram showing a state in which compressed air is supplied to the second inner chamber of the pneumatic cylinder and compressed air is discharged from the first inner chamber of the pneumatic cylinder. [Figure 3] FIG. 3 is a schematic circuit diagram showing a state in which compressed air is supplied to a first inner chamber of a pneumatic cylinder and compressed air is discharged from a second inner chamber of the pneumatic cylinder. [Figure 4] FIG. 4 is a schematic explanatory diagram showing a state in which fluorescence is emitted from the inspected portion of the pipe. [Figure 5] FIG. 5 is a schematic explanatory diagram showing a state in which fluorescence is emitted from one pneumatic cylinder (or one pipe joint). DETAILED DESCRIPTION OF THE INVENTION

[0012] In the following description, the term "leakage point" refers to a point where compressed air leaks. The term "upstream" refers to the upstream side in the flow direction of compressed air. The term "downstream" refers to the downstream side in the flow direction of compressed air.

[0013] 1 is a schematic circuit diagram of a pneumatic equipment system 10. The pneumatic equipment system 10 has a compressor 12 and a main pipe 14 connected to the compressor 12. The compressor 12 generates compressed air by drawing in and compressing atmospheric air.

[0014] A plurality of first sub-pipes 16 are connected to the main pipe 14. A plurality of (three in this case) second sub-pipes 18 are connected to each first sub-pipe 16. A first pneumatic cylinder 20, a second pneumatic cylinder 22, and a third pneumatic cylinder 24 are connected to each second sub-pipe 18, respectively. The first to third pneumatic cylinders 20, 22, and 24 are a type of pneumatic equipment. Compressed air obtained by the compressor 12 flows through the main pipe 14, the first sub-pipe 16, and the second sub-pipe 18. The compressed air is supplied individually to the first to third pneumatic cylinders 20, 22, and 24. The first to third pneumatic cylinders 20, 22, and 24 operate individually using this compressed air as working air.

[0015] A piping inspection system 30 is incorporated into the first secondary piping 16. That is, the piping inspection system 30 is a system that inspects an inspected portion 32 of the first secondary piping 16 to determine whether or not there is a leak point.

[0016] The piping inspection system 30 has a first branch pipe 34. The upstream of the first branch pipe 34 branches off from the first secondary pipe 16 upstream of the inspected portion 32. The downstream of the first branch pipe 34 merges with the first secondary pipe 16. The junction of the first branch pipe 34 and the first secondary pipe 16 is downstream of the branch point of the first branch pipe 34 and upstream of the inspected portion 32. A first valve 36 is provided in the first secondary pipe 16 upstream of the inspected portion 32. The first valve 36 is located in the first secondary pipe 16 between the branch point of the first branch pipe 34 and the junction point.

[0017] A second valve 38 is provided in the first branch pipe 34. When the first valve 36 is open and the second valve 38 is closed, compressed air flows through the first sub-pipe 16 but does not flow through the first branch pipe 34. Conversely, when the first valve 36 is closed and the second valve 38 is open, compressed air flows through the first branch pipe 34 but does not flow through the first sub-pipe 16.

[0018] A first fluorescent solvent supply unit 40 is provided in the first branch pipe 34 downstream of the second valve 38. The first fluorescent solvent supply unit 40 has a first mist generator 42. A specific example of the first mist generator 42 is a lubricator. A lubricator is a well-known container that contains lubricating oil. Alternatively, a well-known bubbler can be used as the first mist generator 42.

[0019] The first mist generator 42 contains a first fluorescent solvent 44. In this embodiment, the first fluorescent solvent 44 is obtained by diluting a fluorescent agent with a solvent. The solvent for the first fluorescent solvent 44 is, for example, water. In this case, the first fluorescent solvent 44 is an aqueous solution of the fluorescent agent. Alternatively, water to which oil has been added may be used as the solvent. In this case, the first fluorescent solvent 44 is an aqueous emulsion solution of the fluorescent agent. Specific examples of the fluorescent agent include coumarin and vitamin B2.

[0020] As described above, compressed air flows through the first branch pipe 34. When the compressed air is discharged toward the first fluorescent solvent 44 in the first mist generator 42, the first fluorescent solvent 44 is turned into mist. That is, a mist of the first fluorescent solvent 44 is generated. The mist flows through the first branch pipe 34 along with the compressed air and moves to the inspected portion 32 of the first sub-pipe 16.

[0021] The piping inspection system 30 has a second branch pipe 46. The upstream of the second branch pipe 46 branches off from the first secondary pipe 16 downstream of the inspected portion 32. In this embodiment, the downstream of the second branch pipe 46 merges with the first secondary pipe 16. The junction of the second branch pipe 46 and the first secondary pipe 16 is downstream of the branch point of the second branch pipe 46 and downstream of the inspected portion 32. A third valve 48 is provided in the first secondary pipe 16 downstream of the inspected portion 32. The third valve 48 is located in the first secondary pipe 16 between the branch point of the second branch pipe 46 and the junction point.

[0022] A fourth valve 50 is provided in the second branch pipe 46. When the third valve 48 is open and the fourth valve 50 is closed, compressed air flows through the first secondary pipe 16 but does not flow through the second branch pipe 46. Conversely, when the third valve 48 is closed and the fourth valve 50 is open, compressed air flows through the second branch pipe 46 but does not flow through the first secondary pipe 16.

[0023] A first fluorescent solvent recovery section 52 is provided in the second branch pipe 46 downstream of the fourth valve 50. The first fluorescent solvent recovery section 52 has a first filter 54. The first filter 54 removes the first fluorescent solvent 44 (mist) contained in the compressed air from the compressed air. Therefore, compressed air that does not contain mist flows downstream of the first filter 54.

[0024] A first exhaust pipe 56 (exhaust section) branches off from the second branch pipe 46 downstream of the first filter 54. A fifth valve 58 is provided at the end of the first exhaust pipe 56. An outlet port of the fifth valve 58 is open to the atmosphere via a first silencer 60.

[0025] The first to fifth valves 36, 38, 48, 50, and 58 are, for example, automatic on-off valves, or may be manual on-off valves.

[0026] The piping inspection system 30 includes a first black light 62. The first black light 62 is supported, for example, by a stand (not shown). The stand is provided with casters (not shown). Therefore, the stand and the first black light 62 can be moved by the rolling of the casters. The first black light 62 moves toward or away from the inspected portion 32.

[0027] The first black light 62 irradiates the inspection target portion 32 with ultraviolet light. If a leak exists in the inspection target portion 32 and compressed air is leaking from the leak, compressed air and a fluorescent solvent (mist) will be ejected from the leak. When the ultraviolet light illuminates the fluorescent solvent, enhanced fluorescence F will be observed, as shown schematically in FIG. 4.

[0028] A regulator 64 is provided in the first secondary pipe 16 downstream of the joining point with the second branch pipe 46. In the first secondary pipe 16, downstream of the regulator 64, an equipment inspection system 70 is incorporated.

[0029] The equipment inspection system 70 is a system that identifies, from among a plurality of first secondary pipes 16, the first secondary pipe 16 to which the first to third pneumatic cylinders 20, 22, 24 or pipe joints 128, 130 from which compressed air is leaking are connected. The equipment inspection system 70 is also a system that identifies from which of the first to third pneumatic cylinders 20, 22, 24 or pipe joints 128, 130 compressed air is leaking.

[0030] The equipment inspection system 70 has a first branch pipe 72. The upstream of the first branch pipe 72 branches off from the first secondary pipe 16. The downstream of the first branch pipe 72 merges with the first secondary pipe 16. The merger point between the first branch pipe 72 and the first secondary pipe 16 is downstream of the branch point of the first branch pipe 72 and upstream of the second secondary pipe 18. A first solenoid valve 74 is provided in the first secondary pipe 16 downstream of the branch point of the first branch pipe 72.

[0031] A second solenoid valve 76 is provided in the first branch pipe 72. When the first solenoid valve 74 is open and the second solenoid valve 76 is closed, compressed air flows through the first sub-pipe 16 but does not flow through the first branch pipe 72. Conversely, when the first solenoid valve 74 is closed and the second solenoid valve 76 is open, compressed air flows through the first branch pipe 72 but does not flow through the first sub-pipe 16.

[0032] A second fluorescent solvent supply unit 78 is provided in the first branch pipe 72 downstream of the second solenoid valve 76. Similar to the first fluorescent solvent supply unit 40, the second fluorescent solvent supply unit 78 has a second mist generator 80. Specific examples of the second mist generator 80 include a lubricator or a bubbler, similar to the first mist generator 42.

[0033] The second mist generator 80 contains a second fluorescent solvent 82. In this embodiment, the second fluorescent solvent 82 is obtained by diluting the fluorescent agent described above with a solvent. The solvent for the second fluorescent solvent 82 is, for example, a highly volatile organic solvent. In particular, an organic solvent that has low solubility in the sealing materials or greases in the first to third pneumatic cylinders 20, 22, and 24 is preferred. Suitable examples of such organic solvents are alcohols. The organic solvent may be a diluted alcohol. A specific example of the alcohol is ethanol. In this case, the second fluorescent solvent 82 is an ethanol solution of the fluorescent agent.

[0034] As described above, compressed air flows through the first branch pipe 72. When the compressed air is discharged toward the second fluorescent solvent 82 inside the second mist generator 80, the second fluorescent solvent 82 is turned into mist. That is, a mist of the second fluorescent solvent 82 is generated. The mist of the second fluorescent solvent 82 flows through the first branch pipe 72 along with the compressed air and moves to the first sub-pipe 16.

[0035] A second exhaust pipe 84 is provided in the first branch pipe 72. A second fluorescent solvent recovery section 86 is provided in the second exhaust pipe 84. The second fluorescent solvent recovery section 86 has a second filter 88. The second filter 88 removes the second fluorescent solvent 82 (mist) contained in the compressed air from the compressed air. Therefore, in the second exhaust pipe 84, compressed air that does not contain mist flows downstream of the second filter 88.

[0036] A sixth valve 90 is provided at the end of the second exhaust pipe 84. The sixth valve 90 is an automatic on-off valve or a manual on-off valve. An outlet port of the sixth valve 90 is open to the atmosphere via a second silencer 92.

[0037] The equipment inspection system 70 has a second branch pipe 94. The upstream of the second branch pipe 94 branches off from the first secondary pipe 16. The downstream of the second branch pipe 94 merges with the first secondary pipe 16. The point where the second branch pipe 94 and the first secondary pipe 16 merge is downstream of the branch point of the second branch pipe 94 and upstream of the second secondary pipe 18.

[0038] The second branch pipe 94 is provided with a third solenoid valve 96 and a digital flow switch 98. The third solenoid valve 96 is located upstream of the digital flow switch 98. The digital flow switch 98 measures the flow rate of compressed air flowing through the second branch pipe 94. In other words, the digital flow switch 98 is a flow rate measuring device. The digital flow switch 98 also functions as a flow rate adjustment valve.

[0039] The first solenoid valve 74, the second solenoid valve 76, and the third solenoid valve 96 are electrically connected to a valve control device 100. The valve control device 100 controls the first solenoid valve 74, the second solenoid valve 76, and the third solenoid valve 96 to open and close the first solenoid valve 74, the second solenoid valve 76, and the third solenoid valve 96. In other words, the first solenoid valve 74, the second solenoid valve 76, and the third solenoid valve 96 are automatically opened and closed by the valve control device 100. In addition, the digital flow switch 98 is electrically connected to a personal computer (PC) 102. The digital flow switch 98 measures the flow rate of compressed air flowing through the second branch pipe 94. The PC 102 records the measured flow rate. In other words, the PC 102 is a storage device.

[0040] 1 illustrates an example in which three second sub-pipes 18 branch off from one first sub-pipe 16. A fourth solenoid valve 104, a fifth solenoid valve 106, and a sixth solenoid valve 108 are provided in each of the three second sub-pipes 18. The number of second sub-pipes 18 is not particularly limited to three. The number of solenoid valves is typically the same as the number of second sub-pipes 18.

[0041] As shown in FIG. 2 , the fourth solenoid valve 104 has a first port 110, a second port 112, a third port 114, a fourth port 116, and a fifth port 118. A first discharge pipe 120 is connected to the first port 110. A second sub-pipe 18 is connected to the second port 112. A second discharge pipe 122 is connected to the third port 114. A first connecting pipe 124 is connected to the fourth port 116. A second connecting pipe 126 is connected to the fifth port 118. The first connecting pipe 124 connects the fourth solenoid valve 104 and the first pneumatic cylinder 20 via a first pipe joint 128. Similarly, the second connecting pipe 126 connects the fourth solenoid valve 104 and the first pneumatic cylinder 20 via a second pipe joint 130.

[0042] A first internal chamber 140 and a second internal chamber 142 are formed inside the first pneumatic cylinder 20. Compressed air is supplied to or exhausted from the first internal chamber 140 via a first connecting pipe 124. Compressed air is supplied to or exhausted from the second internal chamber 142 via a second connecting pipe 126.

[0043] 2 shows a case where compressed air is supplied to the second inner chamber 142 and discharged from the first inner chamber 140. At this time, the compressed air that has flowed through the second sub-pipe 18 moves from the second port 112 to the fifth port 118 within the fourth solenoid valve 104. The compressed air then flows through the second connecting pipe 126 via the fifth port 118 and into the second inner chamber 142. The compressed air within the second inner chamber 142 presses the piston 144 in the direction of arrow X. As a result, the piston 144 moves in the direction of arrow X in FIG. 2.

[0044] Meanwhile, the compressed air in the first inner chamber 140 is pushed out by the piston 144 into the first connecting pipe 124. The compressed air then moves from the fourth port 116 to the first port 110 inside the fourth solenoid valve 104. Furthermore, the compressed air is discharged into the first discharge pipe 120 via the first port 110. During the above process, the third port 114 is in a closed state.

[0045] As shown in FIG. 3, when the piston 144 is moved in the Y direction, which is opposite to the X direction, compressed air is supplied to the first inner chamber 140 and discharged from the second inner chamber 142. At this time, the compressed air that has flowed through the second sub-pipe 18 moves from the second port 112 to the fourth port 116 within the fourth solenoid valve 104. The compressed air then flows through the first connecting pipe 124 via the fourth port 116 and into the first inner chamber 140. The compressed air within the first inner chamber 140 presses the piston 144 in the direction of the arrow Y. The piston 144 moves in the direction of the arrow Y in FIG. 3.

[0046] Meanwhile, the compressed air in the second inner chamber 142 is pushed out by the piston 144 into the second connecting pipe 126. The compressed air then moves from the fifth port 118 to the third port 114 inside the fourth solenoid valve 104. The compressed air is then discharged into the second discharge pipe 122 via the third port 114. During the above process, the first port 110 is in a closed state.

[0047] The above-described configuration and operation are the same for the fifth solenoid valve 106 and the second pneumatic cylinder 22 connected to the fifth solenoid valve 106. Therefore, the same components as those described above are given the same reference numerals, and detailed descriptions thereof will be omitted. Similarly, for the sixth solenoid valve 108 and the third pneumatic cylinder 24 connected to the sixth solenoid valve 108, the same components as those described above are given the same reference numerals, and detailed descriptions thereof will be omitted.

[0048] All of the first exhaust pipes 120 and all of the second exhaust pipes 122 are connected to a single third exhaust pipe 150 (exhaust section). The third exhaust pipe 150 is provided with a third fluorescent solvent recovery section 152. The third fluorescent solvent recovery section 152 has a third filter 154. Similar to the first filter 54 and the second filter 88, the third filter 154 removes the second fluorescent solvent 82 (mist) contained in the compressed air from the compressed air. Therefore, compressed air not containing mist flows downstream of the third filter 154. The third exhaust pipe 150 downstream of the third filter 154 is open to the atmosphere via a third silencer 156.

[0049] The equipment inspection system 70 includes a second black light 158. The second black light 158 is supported, for example, on a stand (not shown). The stand is provided with casters (not shown). Therefore, the stand and the second black light 158 can be moved by the rolling of the casters. The second black light 158 moves toward or away from the first to third pneumatic cylinders 20, 22, 24.

[0050] The second black light 158 irradiates the first to third pneumatic cylinders 20, 22, 24 and their surrounding areas with ultraviolet light. If a leak exists in any of the first to third pneumatic cylinders 20, 22, 24, the first pipe fitting 128, or the second pipe fitting 130, compressed air and fluorescent solvent (mist) will be ejected from the leak, as shown schematically in Fig. 5. When the ultraviolet light illuminates the fluorescent solvent, enhanced fluorescence F can be observed.

[0051] In Fig. 1, for ease of understanding, the first secondary pipe 16 and the second secondary pipe 18 are shown as straight seamless pipes. However, the first secondary pipe 16 and the second secondary pipe 18 are not limited to straight seamless pipes. Alternatively, the first secondary pipe 16 and the second secondary pipe 18 may be seamless pipes bent at a predetermined angle. The first secondary pipe 16 and the second secondary pipe 18 may also be connecting pipes in which multiple seamless pipes are connected via pipe joints.

[0052] In this embodiment, the pneumatic equipment system 10 including the piping inspection system 30 and the equipment inspection system 70 is basically configured as described above. Next, the effects of the piping inspection system 30 and the equipment inspection system 70 will be described in relation to a leak inspection method. The leak inspection method has the steps described in detail below. Note that the leak inspection method includes methods for inspecting leaks in piping and equipment.

[0053] The leak inspection of the piping and the leak inspection of the pneumatic equipment (in this embodiment, the first to third pneumatic cylinders 20, 22, 24) are carried out, for example, before starting operation of the pneumatic equipment system 10. Hereinafter, this case will be described as an example.

[0054] First, the presence or absence of a leak is inspected for the inspected portion 32 of the first sub-pipe 16 shown in FIG. 1. Specifically, ultraviolet light is irradiated onto the inspected portion 32 from the first black light 62. The first valve 36 and the third valve 48 provided on the first sub-pipe 16 are closed. In this state, compressed air is supplied from the compressor 12 to the main pipe 14. The compressed air is distributed to each of the multiple first sub-pipes 16. Because the first valve 36 is closed, the compressed air is prevented from flowing downstream of the first valve 36 in the first sub-pipe 16.

[0055] Next, the second valve 38 and the fourth valve 50 are opened. The second valve 38 and the fourth valve 50 may be opened before compressed air is supplied from the compressor 12 to the main pipe 14. If necessary, the fifth valve 58 is also opened.

[0056] When the second valve 38 is opened, compressed air flows through the first branch pipe 34. The compressed air is discharged toward the first fluorescent solvent 44 inside the first mist generator 42. As a result, a mist of the first fluorescent solvent 44 is generated. After flowing through the first branch pipe 34 along with the compressed air, the mist flows into the inspected portion 32 of the first sub-pipe 16.

[0057] Therefore, compressed air containing mist flows through the inspected portion 32. Because the third valve 48 is closed and the fourth valve 50 is open, the compressed air containing mist flows through the inspected portion 32 and then into the second branch pipe 46. Here, the solvent of the first fluorescent solvent 44 is water, an aqueous emulsion solution, or the like. The vapor pressure of water or an aqueous emulsion solution is relatively low. For this reason, there is no particular need to design the first sub-pipe 16, the first branch pipe 34, the second branch pipe 46, the first mist generator 42, the first filter 54, and the like to have a pressure-resistant structure that takes into account the vapor pressure when the mist evaporates.

[0058] The second branch pipe 46 is provided with a first fluorescent solvent recovery section 52. The first fluorescent solvent recovery section 52 has a first filter 54. The mist (first fluorescent solvent 44) contained in the compressed air is collected by the first filter 54. This collection removes the mist from the compressed air. The compressed air from which the mist has been removed flows into the first exhaust pipe 56. When the fifth valve 58 is open, the compressed air is released from the fifth valve 58 through the first silencer 60 into the atmosphere.

[0059] In contrast, when the fifth valve 58 is closed, the compressed air from which the mist has been removed returns to the first sub-pipe 16 via the second branch pipe 46. The point at which the compressed air returns to the first sub-pipe 16 is downstream of the third valve 48 on the first sub-pipe 16. The compressed air is then supplied to the equipment inspection system 70. Because the mist has been removed from the compressed air, there is no risk of water, which serves as a solvent, flowing into the first solenoid valve 74 to the sixth solenoid valve 108 or the first to third pneumatic cylinders 20, 22, 24, etc. This eliminates the risk of corrosion occurring in the first solenoid valve 74 to the sixth solenoid valve 108 or the first to third pneumatic cylinders 20, 22, 24, etc.

[0060] During the above-described compressed air flow process, if there is no leak in the inspected portion 32, no fluorescence will be observed from the inspected portion 32. The leak may be, for example, a hole, a crack, or a pipe joint that is not tight enough. In contrast, if there is a leak in the inspected portion 32, compressed air and mist (first fluorescent solvent 44) will be ejected from the leak. The mist contains a fluorescent agent. When ultraviolet light is irradiated onto the fluorescent agent, enhanced fluorescence F is observed, as shown in FIG. 4. The inspector can recognize that compressed air is leaking based on the fluorescence F observed.

[0061] In the example shown in Figure 4, the fluorescence F is radiating from a single point. The point where the fluorescence F starts to diffuse is the leakage point. In this way, by examining the point where the fluorescence F starts to diffuse, the leakage point can be easily identified in a short amount of time.

[0062] Furthermore, fluorescence F is observed even when the amount of compressed air leaked is minute. Therefore, even if the leak point is a tiny hole, for example, the inspector can detect the leak point without overlooking it. Moreover, the inspector does not need to have special knowledge to determine whether or not there is a leak. Similarly, the inspector does not need to have special knowledge to identify the leak point.

[0063] Furthermore, the inspector can determine in a short time whether there is a leak based on whether or not the fluorescence F is generated. That is, the inspector can easily determine whether or not there is a leak, regardless of the level of skill or knowledge acquired. It is also easy for the inspector to identify the leak location.

[0064] Next, the equipment inspection system 70 is used to inspect whether there are any leaks in the first to third pneumatic cylinders 20, 22, 24 (and the pipe joints 128, 130). To do this, the fifth valve 58 is closed, and the compressed air that has flowed through the first branch pipe 34, the portion to be inspected 32, and the second branch pipe 46 as described above is supplied to the first to third pneumatic cylinders 20, 22, 24 via the regulator 64. In this case, it is possible to simultaneously inspect for leaks in the piping (portion to be inspected 32) and the first to third pneumatic cylinders 20, 22, 24 (and the pipe joints 128, 130).

[0065] Alternatively, the first valve 36 and the third valve 48 are switched to an open state, and the second valve 38 and the fourth valve 50 are switched to a closed state. As a result, the compressed air flows only through the first sub-pipe 16 without flowing through the first branch pipe 34 and the second branch pipe 46. This compressed air passes through the regulator 64 and is supplied to the first to third pneumatic cylinders 20, 22, and 24.

[0066] The valve control device 100 controls the first to third solenoid valves 74, 76, 96 to close the first solenoid valve 74 and the second solenoid valve 76 and open the third solenoid valve 96. As a result, the compressed air that has passed through the regulator 64 flows only into the second branch pipe 94. In this way, when performing a leak test on an equipment, compressed air flows through the second branch pipe 94 instead of the first sub-pipe 16. The digital flow switch 98 measures the flow rate of the compressed air flowing through the second branch pipe 94 and converts the flow rate into an information signal. The PC 102 records the information signal as a flow rate. The display of the PC 102 displays a graph with the horizontal axis representing elapsed time and the vertical axis representing flow rate.

[0067] The compressed air that has flowed through the second branch pipe 94 flows into each of the multiple second sub-pipes 18. The compressed air passes through the fourth solenoid valve 104, the fifth solenoid valve 106, and the sixth solenoid valve 108, and is introduced from the second connecting pipe 126 into the second internal chambers 142 of the first to third pneumatic cylinders 20, 22, and 24 (see FIG. 2). Therefore, the pistons 144 move in the X direction. The compressed air in the first internal chamber 140 passes through the first connecting pipe 124, the fourth solenoid valve 104, the fifth solenoid valve 106, and the sixth solenoid valve 108. After passing through the first exhaust pipe 120, the compressed air in the first internal chamber 140 is discharged into the atmosphere from the third exhaust pipe 150 via the third silencer 156.

[0068] If there are no leaks in the first to third pneumatic cylinders 20, 22, 24 (and the pipe joints 128, 130), when the piston 144 reaches the forward end after a predetermined time has elapsed, the flow of compressed air from the second sub-pipe 18 to the second internal chambers 142 of the first to third pneumatic cylinders 20, 22, 24 will apparently stop. At the same time, the release of compressed air from the first internal chambers 140 of the first to third pneumatic cylinders 20, 22, 24 to the atmosphere will also apparently stop. At this time, the flow rate of compressed air in the second branch pipe 94 is zero.

[0069] In contrast, for example, if a leak exists in the first pneumatic cylinder 20, compressed air continues to flow from the second branch pipe 94 toward the first pneumatic cylinder 20 even after the piston 144 reaches the forward end. The compressed air supplied to the first pneumatic cylinder 20 is released into the atmosphere from the leak. Therefore, after a predetermined time has elapsed since the second branch pipe 94 started to supply compressed air to the first to third pneumatic cylinders 20, 22, and 24, the flow rate of compressed air in the second branch pipe 94 is greater than zero. An inspector can recognize that the flow rate of compressed air in the second branch pipe 94 is greater than zero by checking the indicator of the digital flow switch 98 or the display of the PC 102.

[0070] In other words, the inspector can determine that there is a leak in any of the first to third pneumatic cylinders 20, 22, 24 (or pipe joints 128, 130) based on the fact that the flow rate of compressed air in the second branch pipe 94 is greater than 0. Next, the inspector performs the task of identifying which of the first to third pneumatic cylinders 20, 22, 24 (or pipe joints 128, 130) is leaking.

[0071] Specifically, while the first solenoid valve 74 is kept closed, the inspector operates the valve control device 100 to close the second solenoid valve 76. Open Also, the inspector operates the valve control device 100 to switch the third electromagnetic valve 96 to the closed By the above operation, compressed air flows only through the first branch pipe 72. Furthermore, the second black light 158 irradiates the areas around the first to third pneumatic cylinders 20, 22, and 24 with ultraviolet light.

[0072] The compressed air flowing through the first branch pipe 72 is discharged toward the second fluorescent solvent 82 inside the second mist generator 80. As a result, a mist of the second fluorescent solvent 82 is generated. After flowing through the first branch pipe 72 along with the compressed air, the mist passes through the first secondary pipe 16 and is distributed to each of the multiple second secondary pipes 18.

[0073] The compressed air containing the mist then passes through the fourth solenoid valve 104 to the sixth solenoid valve 108, respectively, and is supplied to the first to third pneumatic cylinders 20, 22, and 24, respectively. Preferably, compressed air is first supplied to the first inner chamber 140 (or the second inner chamber 142) and then discharged from the second inner chamber 142 (or the first inner chamber 140). After a predetermined time has passed, the supply destination of the compressed air is switched. That is, compressed air is supplied to the second inner chamber 142 (or the first inner chamber 140) and then discharged from the first inner chamber 140 (or the second inner chamber 142).

[0074] The first pneumatic cylinder 20 will be described as an example. When compressed air is supplied to the second inner chamber 142, the compressed air in the first inner chamber 140 flows through the first connecting pipe 124, the fourth port 116 of the fourth solenoid valve 104, the first port 110 of the fourth solenoid valve 104, the first discharge pipe 120, and the third exhaust pipe 150, in that order (see FIG. 2). Conversely, when compressed air is supplied to the first inner chamber 140, the compressed air in the second inner chamber 142 flows through the second connecting pipe 126, the fifth port 118 of the fourth solenoid valve 104, the third port 114 of the fourth solenoid valve 104, the second discharge pipe 122, and the third exhaust pipe 150, in that order (see FIG. 3). In the second pneumatic cylinder 22, the compressed air passes through the fifth solenoid valve 106 instead of the fourth solenoid valve 104. In the third pneumatic cylinder 24, the compressed air passes through a sixth solenoid valve 108 instead of the fourth solenoid valve 104.

[0075] The third exhaust pipe 150 is provided with a third fluorescent solvent recovery section 152. The third fluorescent solvent recovery section 152 has a third filter 154. The mist (second fluorescent solvent 82) contained in the compressed air is collected by the third filter 154. This collection removes the mist from the compressed air. The compressed air from which the mist has been removed is released into the atmosphere from the third exhaust pipe 150 via a third silencer 156.

[0076] For example, if there is a leak only in the first pneumatic cylinder 20, in the above-mentioned circulation process, as shown in Figure 5, fluorescence F is observed diffusing from the leak point in the first pneumatic cylinder 20. In contrast, fluorescence F is not observed in the second pneumatic cylinder 22 or the third pneumatic cylinder 24. Therefore, based on the fact that fluorescence F is observed in the first pneumatic cylinder 20 but not in the second pneumatic cylinder 22 or the third pneumatic cylinder 24, an inspector can determine that the compressed air leak point is the first pneumatic cylinder 20.

[0077] A case will be described where there is a leak in the second pipe fitting 130 connecting the first pneumatic cylinder 20 and the second connecting pipe 126. In this case, for example, while compressed air is being supplied to the first inner chamber 140 and discharged from the second inner chamber 142, fluorescence F is observed diffusing from the second pipe fitting 130 of the first pneumatic cylinder 20. In contrast, no fluorescence F is observed in the second pipe fittings 130 of the second pneumatic cylinder 22 and the third pneumatic cylinder 24. Based on this observation result, an inspector can determine that the compressed air is leaking from the second pipe fitting 130 of the first pneumatic cylinder 20.

[0078] In this way, according to the equipment inspection system 70, first, from among the plurality of first secondary pipes 16, the first secondary pipe 16 to which the first to third pneumatic cylinders 20, 22, 24 (or pipe joints 128, 130) connected, from which a leak of mist-containing compressed air is occurring, is identified. In this case, ultraviolet light is irradiated only onto the first to third pneumatic cylinders 20, 22, 24 determined to be leaking and their surrounding areas. Next, based on the enhancement of the fluorescence F by the ultraviolet light, the pneumatic cylinder (or pipe joint 128, 130) from which a leak is occurring is identified from among the first to third pneumatic cylinders 20, 22, 24 (or pipe joints 128, 130).

[0079] By following the above procedure, it is not necessary to irradiate the first to third pneumatic cylinders 20, 22, 24 (or the pipe joints 128, 130) of the other first sub-pipes 16 with ultraviolet light. Here, the "other first sub-pipes 16" refers to the first sub-pipes 16 for which the flow rate measured by the digital flow switch 98 is zero. In other words, it is determined that no leakage occurs in the first to third pneumatic cylinders 20, 22, 24 (or the pipe joints 128, 130) of the other first sub-pipes 16. That is, it is not necessary to irradiate the first to third pneumatic cylinders 20, 22, 24 (or the pipe joints 128, 130) for which no leakage occurs with ultraviolet light. This allows the second black light 158 to be made smaller.

[0080] In equipment leak inspections, regardless of the inspector's level of skill or knowledge, the inspector can easily determine whether compressed air is leaking from the first to third pneumatic cylinders 20, 22, 24 (or pipe joints 128, 130). In addition, the inspector can easily identify the location of the leak in a short amount of time.

[0081] Compressed air containing a mist of the second fluorescent solvent 82 flows through the fourth solenoid valve 104 to the sixth solenoid valve 108 and the first to third pneumatic cylinders 20, 22, 24, etc. Here, the solvent of the second fluorescent solvent 82 is, for example, a highly volatile organic solvent. In this case, the mist evaporates quickly. Therefore, the mist hardly remains inside the second sub-pipe 18, the fourth solenoid valves 104 to the sixth solenoid valves 108, and the first to third pneumatic cylinders 20, 22, 24, etc. Therefore, failure or corrosion caused by the mist of the second fluorescent solvent 82 in the fourth solenoid valves 104 to the sixth solenoid valves 108 and the first to third pneumatic cylinders 20, 22, 24, etc. is avoided.

[0082] Furthermore, because the mist evaporates quickly, there is almost no chance that the lubricant (grease, etc.) inside the fourth solenoid valve 104 to the sixth solenoid valve 108 and the first to third pneumatic cylinders 20, 22, 24 will be eluted into the mist. This prevents any adverse effects on the sealing or operational performance of the fourth solenoid valve 104 to the sixth solenoid valve 108 and the first to third pneumatic cylinders 20, 22, 24.

[0083] The fourth solenoid valve 104 to the sixth solenoid valve 108 and the first to third pneumatic cylinders 20, 22, 24, etc. are mainly made of metal. Metal materials are chemically stable against organic solvents. Therefore, when the solvent of the second fluorescent solvent 82 is an organic solvent, failure or corrosion of the fourth solenoid valve 104 to the sixth solenoid valve 108 and the first to third pneumatic cylinders 20, 22, 24, etc. is further prevented.

[0084] In particular, metal materials are chemically stable against alcohols such as ethanol. Moreover, alcohols are highly volatile. Therefore, the solvent of the second fluorescent solvent 82 is preferably an alcohol such as ethanol.

[0085] Furthermore, the fourth solenoid valve 104 to the sixth solenoid valve 108 and the first to third pneumatic cylinders 20, 22, 24, etc. have a pressure-resistant structure. Therefore, even when the mist evaporates, there is no concern that the fourth solenoid valve 104 to the sixth solenoid valve 108 and the first to third pneumatic cylinders 20, 22, 24, etc. will be deformed by vapor pressure.

[0086] After the leak inspection is completed in this manner, the inspected part 32 or device that is determined to have a leak is replaced. Thereafter, the leak inspection is repeated until no more leaks are detected.

[0087] After all leak inspections are completed, 6 valve 90 is opened. Accordingly, mist and compressed air are released from the first branch pipe 72 into the atmosphere via the second silencer 92. Therefore, mist is prevented from accumulating in the first branch pipe 72.

[0088] When the pneumatic equipment system 10 is operated, the first valve 36, the third valve 48, and the first solenoid valve 74 are open, and the second valve 38, the fourth valve 50, the fifth valve 58, the second solenoid valve 76, and the third solenoid valve 96 are closed. As a result, compressed air leaving the compressor 12 passes through the main pipe 14 and is distributed to each of the first sub-pipes 16. The compressed air is then distributed to each of the second sub-pipes 18 and becomes working air that operates the first to third pneumatic cylinders 20, 22, and 24. At this time, the compressed air does not flow through the first branch pipe 34 and the first branch pipe 72. Therefore, no mist accompanies the compressed air.

[0089] As described above, an inspector can determine in a short time whether a leak exists based on whether or not fluorescence F is generated. Therefore, for example, if a compressed air leak occurs due to an unexpected event while the pneumatic equipment system 10 is in operation, the operation of the pneumatic equipment system 10 can be stopped and the leak inspection of the piping or equipment can be completed in a short time. In other words, there is no need to stop the pneumatic equipment system 10 for a long period of time. Therefore, the pneumatic equipment system 10 can be quickly restored.

[0090] As described above, the present embodiment is a piping inspection system (30) that inspects whether or not there is a compressed air leak in an inspected portion (32) of a piping (16) through which compressed air flows, and a first branch pipe (34) that branches off from the pipe upstream of the inspected portion and joins the pipe; a fluorescent solvent supply unit (40) provided in the first branch pipe for supplying a fluorescent solvent (44) to the inspection target portion; a second branch pipe (46) branching off from the piping downstream of the inspected portion; a fluorescent solvent recovery section (52) provided in the second branch pipe for recovering the fluorescent solvent from the inspection target portion; A piping inspection system is disclosed, comprising:

[0091] In this case, whether or not there is a leak in the part being inspected can be easily and quickly determined based on whether or not fluorescence is observed from the part being inspected. Moreover, no special skills or knowledge are required for the inspector to make this determination.

[0092] Furthermore, after flowing through the inspected portion, the fluorescent solvent is recovered by the fluorescent solvent recovery unit. This prevents the fluorescent solvent from flowing downstream of the inspected portion of the piping. That is, the fluorescent solvent is prevented from flowing into pneumatic equipment, etc., connected to the end of the piping. This also prevents the fluorescent solvent from remaining inside the piping or pneumatic equipment. This eliminates concerns about the fluorescent solvent causing damage or corrosion to the pneumatic equipment.

[0093] This embodiment discloses a piping inspection system in which the fluorescent solvent supply unit has a mist generator (42) that turns the fluorescent solvent into mist, and the mist of the fluorescent solvent is supplied to the portion to be inspected.

[0094] Mist disperses more easily than droplets. Therefore, by adding mist to compressed air, it is easy to make the mist (fluorescent solvent) reach the area to be inspected. It is also easy to make the mist (fluorescent solvent) flow out of the area to be inspected.

[0095] This embodiment discloses a piping inspection system in which the fluorescent solvent is an aqueous solution or aqueous emulsion of a fluorescent agent.

[0096] The vapor pressure of water or emulsion water is relatively low. Therefore, it is not easy for the mist to evaporate inside the piping. Therefore, there is no particular need to design the piping inspection system to be pressure-resistant in consideration of the vapor pressure of the mist. This allows for lower capital investment.

[0097] This embodiment discloses a piping inspection system comprising a first valve (36) provided in the piping between the point where the first branch pipe branches and the point where the two branches join, a second valve (38) provided in the first branch pipe upstream of the fluorescent solvent supply section, a third valve (48) provided in the piping downstream of the point where the second branch pipe branches, and a fourth valve (50) provided in the second branch pipe upstream of the fluorescent solvent recovery section.

[0098] In this configuration, the first to fourth valves can be individually switched between open and closed states. This switching allows the fluid flowing through the part to be inspected to be selectively switched between compressed air containing no mist and compressed air containing mist. In other words, it is easy to switch the fluid flowing through the part to be inspected.

[0099] This embodiment discloses a piping inspection system including an exhaust section (56) that is provided in the second branch pipe downstream of the fluorescent solvent recovery section and is open to the atmosphere.

[0100] The fluorescent solvent carried by the compressed air is separated from the compressed air by the fluorescent solvent recovery section. Therefore, compressed air from which the fluorescent solvent has been removed flows downstream of the fluorescent solvent recovery section. However, it is conceivable that, due to unforeseen circumstances, the fluorescent solvent may not be sufficiently removed in the fluorescent solvent recovery section. With the above configuration, in such a situation, the compressed air can be released into the atmosphere. This prevents the fluorescent solvent from flowing into pneumatic equipment, etc., connected to the end of the piping.

[0101] This embodiment discloses a piping inspection system equipped with a black light (62) that irradiates the inspection target portion with ultraviolet light.

[0102] When there is a leak in the piping, compressed air accompanied by mist will spray out from the leak point. When ultraviolet light is irradiated, the fluorescence is enhanced by the ultraviolet light, making it easy to identify the location of the compressed air leak.

[0103] In factories, pipes are quite long. If the configuration described in Patent Document 1 is applied to pipe leak inspection, light sources and cameras must be placed throughout the entire pipe. This requires several dozen light sources and cameras. As a result, capital investment increases.

[0104] In contrast, according to this embodiment, the black light only needs to be large enough to irradiate the area to be inspected with ultraviolet light, which reduces the investment required for equipment.

[0105] The present invention is not limited to the above-described embodiment, and various configurations can be adopted without departing from the gist of the present invention.

[0106] For example, when only testing for compressed air leaks from piping, it is possible to release compressed air into the atmosphere from the fifth valve 58 via the first silencer 60. On the other hand, when only testing for compressed air leaks from equipment, the first valve 36 and the third valve 48 are opened, and the second valve 38, the fourth valve 50, and the fifth valve 58 are closed, and compressed air is supplied to the first branch pipe 72.

[0107] As can be seen from this, it is also possible to carry out the piping leak inspection and the equipment leak inspection separately. Furthermore, there is no particular need to incorporate the piping inspection system 30 and the equipment inspection system 70 into the pneumatic equipment system 10 at the same time. In other words, only the piping inspection system 30 may be incorporated into the pneumatic equipment system 10.

[0108] The pneumatic device is not particularly limited to a pneumatic cylinder, but other specific examples of the pneumatic device include a pneumatic chuck and a pneumatic actuator. [Explanation of symbols]

[0109] 10...Pneumatic equipment system 12...Compressor 14...Main piping 16...First auxiliary piping 18...Second sub-pipe 20, 22, 24...Air cylinder 30...Piping inspection system 32...Inspected part 34...First branch pipe 36...First valve 38... Second valve 40... First fluorescent solvent supply unit 42...First mist generator 44...First fluorescent solvent 46...Second branch pipe 48...Third valve 50...Fourth valve 52...First fluorescent solvent recovery section 54...First filter 56...First exhaust pipe 58...5th valve 62...1st black light 70...Equipment inspection system 72...First branch pipe 74...First solenoid valve 76...Second solenoid valve 78... Second fluorescent solvent supply unit 80... Second mist generator 82...Second fluorescent solvent 84...Second exhaust pipe 86... Second fluorescent solvent recovery section 88... Second filter 90...6th valve 94...2nd branch 96...Third solenoid valve 98...Digital flow switch 100... Valve control device 102... Personal computer 104, 106, 108...Solenoid valves 128, 130...Pipe fittings 144...Piston 150...Third exhaust pipe 152...Third fluorescent solvent recovery section 154...Third filter 158...Second black light F...Fluorescent

Claims

1. A piping inspection system that is arranged upstream of a pneumatic device in the direction of compressed air flow in order to inspect whether or not there is a compressed air leak in an inspected portion of the piping that supplies compressed air to the pneumatic device, a first branch pipe branching from the pipe upstream of the inspected portion and joining the pipe; a fluorescent solvent supply unit provided in the first branch pipe for supplying a fluorescent solvent to the inspection target portion; a second branch pipe branching from the piping downstream of the inspected portion; a fluorescent solvent recovery unit provided in the second branch pipe for recovering the fluorescent solvent from the inspection target portion; Equipped with The piping inspection system, wherein the second branch pipe and the fluorescent solvent recovery unit are arranged upstream of the pneumatic device.

2. 2. The piping inspection system according to claim 1, wherein the fluorescent solvent supply unit has a mist generator that turns the fluorescent solvent into a mist, and supplies the mist of the fluorescent solvent to the portion to be inspected.

3. 3. The piping inspection system according to claim 1, wherein the fluorescent solvent is an aqueous solution or an aqueous emulsion of a fluorescent agent.

4. 4. A piping inspection system as described in any one of claims 1 to 3, comprising: a first valve provided in the piping between the point where the first branch pipe branches and the point where the two branches join; a second valve provided in the first branch pipe upstream of the fluorescent solvent supply unit; a third valve provided in the piping downstream of the point where the second branch pipe branches; and a fourth valve provided in the second branch pipe upstream of the fluorescent solvent recovery unit.

5. A piping inspection system according to any one of claims 1 to 4, further comprising an exhaust section that is provided downstream of the fluorescent solvent recovery section in the second branch pipe and is open to the atmosphere.

6. 6. The piping inspection system according to claim 1, further comprising a black light for irradiating the portion to be inspected with ultraviolet light.

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