Inspection liquid supply device

Abstract

An inspection liquid supply device (10) is provided with: an introduction port (20) that introduces compressed air to the upstream of a mist supply unit (18) that supplies a mist-form inspection liquid; a discharge port (32) that allows the compressed air to flow out; a first flow path (26) that communicates with the discharge port (32); a second flow path (28) that is provided in parallel with the first flow path (26), communicates with the discharge port (32), and has a pressure intensifying valve (48) partway through the second flow path (28); and a first switching valve (24) that connects either the first flow path (26) or the second flow path (28) to the introduction port (20).

Description

Test liquid supply device

[0001] The present invention relates to a test liquid supplying device that supplies a test liquid in mist form to a test object.

[0002] Leak tests are sometimes performed to check for leaks in equipment that requires a certain level of sealing, compressed air piping systems in factories, etc. For such leak tests, for example, an inspection device described in JP 2023-39662 A is used. The inspection device in JP 2023-39662 A turns a colored inspection liquid into a mist and supplies it to the test object together with compressed air.

[0003] Since leak inspections are performed only occasionally, it would be wasteful to always have a leak inspection system installed at the inspection target. Meanwhile, the inspection conditions for the equipment or piping being inspected vary. For example, the pressure of compressed air supplied to the equipment or piping must be changed depending on whether there is compressed air remaining inside the equipment or piping being inspected or not. Therefore, there is a demand for a leak inspection device that can accommodate a variety of inspection targets and inspection conditions.

[0004] An object of the present invention is to solve the above-mentioned problems.

[0005] One aspect of the following disclosure is a test liquid supply device comprising: an inlet port for introducing compressed air; an exhaust port for discharging the compressed air; a first flow path communicating with the exhaust port; a second flow path arranged parallel to the first flow path and communicating with the exhaust port, the second flow path having a booster valve thereon; a first switching valve connecting either the first flow path or the second flow path to the inlet port; and a mist supply unit for supplying mist-like test liquid to the compressed air discharged from the exhaust port.

[0006] The test liquid supplying device according to the above aspect can supply the test liquid mist to the test object by increasing the pressure of the compressed air through the second flow path and the booster valve when compressed air remains inside the test object. Also, when no compressed air remains inside the test object, the test liquid supplying device can supply the test liquid mist to the test object together with a sufficient flow rate of compressed air by supplying compressed air through the first flow path.

[0007] FIG. 1 is a fluid circuit diagram of a test liquid supply device according to an embodiment. FIG. 2A is an external perspective view of the pressure supply unit of FIG. 1, and FIG. 2B is a perspective view showing the interior of the pressure supply unit of FIG. 1. FIG. 3 is an explanatory diagram of an example of connecting the test liquid supply device of FIG. 1 to a piping system as an example of an object to be tested. FIG. 4 is an explanatory diagram of the operation of the test liquid supply device when there is no compressed air inside the object to be tested. FIG. 5 is an explanatory diagram of the pressure-boosting operation of the test liquid supply device when compressed air is present inside the object to be tested. FIG. 6 is a diagram explaining the flow of compressed air during the ON period in the pressure-boosting operation of the test liquid supply device of FIG. 5. FIG. 7 is a diagram explaining the flow of compressed air immediately after switching from the ON period to the OFF period in the pressure-boosting operation of the test liquid supply device of FIG. 5. FIG. 8 is an explanatory diagram of the operation of the test liquid supply device when a portable small air compressor is connected to the test liquid supply device when clean compressed air is not available.

[0008] The test liquid supplying device 10 according to this embodiment is portable and is used to supply a mist of test liquid together with compressed air during leak testing. The test liquid supplying device 10 dyes the leak location of the test object with a coloring agent or fluorescent agent contained in the test liquid, thereby facilitating visual identification of the leak location. The configuration of each part of the test liquid supplying device 10 will be described below. Note that the terms upstream and downstream are used in the following description, and these terms refer to the flow direction of compressed air in a steady operating state.

[0009] 1, the test liquid supply device 10 includes a pressure supply unit 16 and a mist supply unit 18. The pressure supply unit 16 mainly includes an inlet port 20, a filter unit 22, a first switching valve 24, a first flow path 26, a second flow path 28, a pressure booster circuit 30, and an outlet port 32. A compressed air supply source is connected to the inlet port 20.

[0010] The inlet flow path 34 connects the inlet port 20 and the first switching valve 24. The filter unit 22 is provided midway along the inlet flow path 34. The filter unit 22 is a detachable member that is attached when, for example, unclean compressed air is supplied to the inlet port 20. Unclean compressed air refers to compressed air that contains dust, moisture, etc. A small, portable air compressor can be connected to the inlet port 20.

[0011] The filter unit 22 has, from upstream to downstream, a first filter 36, a pressure reducing valve 38, a first pressure gauge 40, and a dryer 42. The first filter 36 removes dust from the introduced compressed air. The pressure reducing valve 38 reduces the pressure of the introduced compressed air to a predetermined level. The first pressure gauge 40 displays the pressure of the compressed air reduced by the pressure reducing valve 38. The dryer 42 is, for example, a membrane filter having a hollow fiber membrane, and removes moisture (condensation water) from the compressed air.

[0012] The first switching valve 24 is a manually operated five-port three-position valve. The inlet flow path 34, the first exhaust section 44a, the second exhaust section 44b, the first flow path 26, and the second flow path 28 are connected to the respective ports of the first switching valve 24. The first switching valve 24 can be switched to three positions: a closed position shown in Figure 1, a direct pressure position shown in Figure 4, and a pressure increase position shown in Figure 5. In the closed position shown in Figure 1, the first switching valve 24 closes each flow path.

[0013] 4, the first switching valve 24 communicates the inlet flow path 34 with the first flow path 26 and communicates the second flow path 28 with the first exhaust section 44a. In addition, the first switching valve 24 communicates the inlet flow path 34 with the second flow path 28 and communicates the first flow path 26 with the second exhaust section 44b in the pressure increasing position of FIG.

[0014] The first flow path 26 has a first upstream end 26a connected to the first switching valve 24 and a second downstream end 26b that merges with the second flow path 28 at a junction 27. The first flow path 26 communicates with the discharge port 32 via the junction 27 with the second flow path 28. A first check valve 46 is provided in the first flow path 26. The first check valve 46 is oriented to allow compressed air flowing toward the second end 26b to pass through. The first check valve 46 prevents compressed air in the second flow path 28 from flowing back toward the first end 26a of the first flow path 26 during the pressure boosting operation (see FIGS. 5 to 7). The first check valve 46 is preferably located near the junction 27 where the first flow path 26 and the second flow path 28 merge.

[0015] The second flow path 28 is a flow path arranged in parallel to the first flow path 26. The second flow path 28 has a third end portion 28a on the upstream side and a fourth end portion 28b on the downstream side. The third end portion 28a on the upstream side is connected to the first switching valve 24, and the fourth end portion 28b is connected to the junction 27. A pressure boosting circuit 30 is provided midway along the second flow path 28.

[0016] The booster circuit 30 mainly comprises a booster valve 48, an accumulator tank 50, a second switching valve 52, and a timer circuit 54 (a first time delay valve 64 and a second time delay valve 66). The booster valve 48 is provided midway through the second flow path 28. The booster valve 48 boosts the pressure of a portion of the compressed air that flows in from the third end 28a of the second flow path 28 and discharges the compressed air toward the fourth end 28b. The accumulator tank 50 is connected downstream of the booster valve 48. The accumulator tank 50 stores the compressed air that has been boosted by the booster valve 48.

[0017] A second switching valve 52 is connected downstream of the accumulator tank 50. A spring check valve 56, a residual pressure exhaust valve 58, and a second pressure gauge 60 are connected to the second flow path 28 between the accumulator tank 50 and the second switching valve 52. The spring check valve 56 exhausts compressed air from the second flow path 28 when the pressure exceeds a predetermined value, preventing excessive pressure buildup. The residual pressure exhaust valve 58 is a gate valve that is operated by a user and is used, for example, to exhaust compressed air stored in the accumulator tank 50 after use. The second pressure gauge 60 displays the pressure of the compressed air stored in the accumulator tank 50.

[0018] The second switching valve 52 is a three-port, two-position valve that is switched between an OFF position and an ON position by supplying or discharging pilot air. In an initial state where pilot air is not supplied, the second switching valve 52 is positioned in the OFF position by a return spring (see FIG. 1 ) and closes the second flow path 28 downstream of the accumulator tank 50. When pilot air is supplied from the timer circuit 54, the second switching valve 52 switches from the OFF position to the ON position. In the ON position, the second switching valve 52 connects the accumulator tank 50 to the discharge port 32. Therefore, in the ON position, the second switching valve 52 releases compressed air stored in the accumulator tank 50 from the discharge port 32.

[0019] The timer circuit 54 has a pilot flow path 62 branching off from the second flow path 28 on the upstream side of the pressure increase valve 48. The timer circuit 54 supplies pilot air to the second switching valve 52 via the pilot flow path 62 during an ON period. The timer circuit 54 also exhausts pilot air from the second switching valve 52 during an OFF period. Specifically, the timer circuit 54 has a first time delay valve 64, a second time delay valve 66, and a third switching valve 68.

[0020] The first time delay valve 64 is a valve for setting the period (OFF period) during which compressed air from the booster valve 48 is stored in the accumulator tank 50. The second time delay valve 66 is a valve for setting the period (ON period) during which compressed air is released from the accumulator tank 50. The third switching valve 68 supplies and exhausts compressed air (drive air) for driving the first time delay valve 64.

[0021] The first time delay valve 64 is disposed midway through the pilot flow path 62. The first time delay valve 64 includes a first inlet port 64a, a first supply / discharge port 64b, a first control port 64c, a fourth switching valve 70, a first throttle valve 72, and a first volume 74. A first portion 62a of the pilot flow path 62 is connected to the first inlet port 64a, and a second portion 62b of the pilot flow path 62 is connected to the first supply / discharge port 64b. The first portion 62a is a portion of the pilot flow path 62 that is connected to the second flow path 28 upstream of the booster valve 48. The second portion 62b is a portion of the pilot flow path 62 that is connected to the pilot port 52P of the second switching valve 52.

[0022] The fourth switching valve 70 is a three-port, two-position valve driven by drive air (pilot air) and connected to the first inlet port 64a, the first supply / exhaust port 64b, and the third exhaust port 67A. In the initial state where drive air is not supplied, the fourth switching valve 70 is positioned in the closed position due to the resilience of a return spring. In the closed position, the fourth switching valve 70 closes the first inlet port 64a and connects the first supply / exhaust port 64b to the third exhaust port 67A. That is, when the fourth switching valve 70 is in the closed position, it discharges pilot air from the second switching valve 52. When drive air is supplied, the fourth switching valve 70 is displaced to the open position. When the fourth switching valve 70 is in the open position, it connects the first inlet port 64a and the first supply / exhaust port 64b and supplies pilot air to the second switching valve 52.

[0023] The first control port 64c is connected to the first drive flow path 65 via a third switching valve 68. The first drive flow path 65 connects the third switching valve 68 and the first portion 62a of the pilot flow path 62. The first control port 64c supplies and exhausts drive air to and from the fourth switching valve 70. A first throttle valve 72 is disposed between the first control port 64c and the fourth switching valve 70. The first throttle valve 72 throttles the flow rate of drive air flowing in from the first control port 64c. The first volume portion 74 is formed by the volume of the flow path between the first throttle valve 72 and the fourth switching valve 70, as well as the volume of the chamber, etc. After the third switching valve 68 starts supplying drive air, the first time delay valve 64 switches the fourth switching valve 70 to the open position after a first delay time set by the first throttle valve 72 has elapsed. The first delay time essentially defines the length of the OFF period.

[0024] The third switching valve 68 is a three-port, two-position valve that is switched by drive air supplied to the drive port 68a. The first drive flow path 65, the first control port 64c, and the fourth exhaust port 67B are connected to the third switching valve 68's ports. In an initial state where drive air is not supplied, the third switching valve 68 is biased by a return spring to its first position. In the first position, the third switching valve 68 connects the first drive flow path 65 to the first control port 64c and supplies drive air to the first time delay valve 64. When drive air is supplied, the third switching valve 68 switches to its second position, connects the fourth exhaust port 67B to the first control port 64c, and closes the first drive flow path 65. In other words, when in the second position, the third switching valve 68 exhausts drive air from the first time delay valve 64.

[0025] The second time delay valve 66 is a component similar to the first time delay valve 64. The second time delay valve 66 has a fifth switching valve 70A, a second throttle valve 72A, a second volume 74A, a second inlet port 66a, a second supply / discharge port 66b, and a second control port 66c. The second inlet port 66a is connected to the first portion 62a of the pilot flow path 62, the second supply / discharge port 66b is connected to the drive port 68a of the third switching valve 68, and the second control port 66c is connected to the second portion 62b of the pilot flow path 62.

[0026] The fifth switching valve 70A is a three-port, two-position valve driven by drive air supplied or discharged from the second control port 66c. The fifth switching valve 70A is connected to the second inlet port 66a, the second supply / exhaust port 66b, and the fifth exhaust port 67C. In the initial state, when drive air is not supplied, the fifth switching valve 70A is positioned in the initial position due to the resilience of a return spring. In the initial position, the fifth switching valve 70A closes the second inlet port 66a and connects the second supply / exhaust port 66b to the fifth exhaust port 67C. In other words, in the initial position, the fifth switching valve 70A exhausts drive air from the third switching valve 68. When drive air is supplied, the fifth switching valve 70A is displaced to the open position. The fifth switching valve 70A in the open position connects the second inlet port 66a and the second supply / discharge port 66b, and supplies drive air (pilot air) from the pilot flow path 62 to the drive port 68a of the third switching valve 68.

[0027] The second control port 66c communicates with the second portion 62b of the pilot flow path 62. The second control port 66c supplies and exhausts drive air to and from the fifth switching valve 70A. The second throttle valve 72A is disposed between the second control port 66c and the fifth switching valve 70A. The second throttle valve 72A throttles the flow rate of drive air flowing in from the second control port 66c. The second volume portion 74A is formed by the volume of the flow path between the second throttle valve 72A and the fifth switching valve 70A, as well as the volume of the chamber, etc. After the supply of pilot air to the second portion 62b of the pilot flow path 62 begins, the second time delay valve 66 switches the fifth switching valve 70A to the open position after a second delay time set by the second throttle valve 72A has elapsed. As a result, the third switching valve 68 switches to the second position, the drive air of the first time delay valve 64 is discharged, and the pilot air of the second switching valve 52 is discharged, resulting in a transition to an OFF period. Therefore, the second delay time substantially defines the length of the ON period.

[0028] As shown in FIG. 2A , the pressure supply unit 16 further includes a box-shaped housing 76. The housing 76 is formed in a rectangular parallelepiped shape and has a bottom surface 76a, a top surface 76b facing the bottom surface 76a, and four side surfaces 76c. The filter unit 22 is attached to one of the side surfaces 76c of the housing 76. The inlet port 20, the first switching valve 24, the exhaust port 32, the residual pressure release valve 58, the second pressure gauge 60, the operation unit of the first time delay valve 64, and the operation unit of the second time delay valve 66 are attached to the top surface 76b of the housing 76. The operation unit of the first time delay valve 64 is a member that adjusts the aperture of the first throttle valve 72A, and the operation unit of the second time delay valve 66 is a member that adjusts the aperture of the second throttle valve 72A.

[0029] 2B , the housing 76 accommodates the booster valve 48, the accumulator tank 50, the spring check valve 56, the second switching valve 52, the third switching valve 68, the spring check valve 56, and the first check valve 46. Such a housing 76 improves the portability and operability of the pressure supply unit 16.

[0030] As shown in Figure 1, the mist supply unit 18 is connected downstream of the exhaust port 32 of the pressure supply unit 16. In this embodiment, the mist supply unit 18 is configured by a lubricator. A lubricator is a device that mixes a mist of lubricating oil into compressed air, but in this embodiment, it is filled with a test liquid containing a colorant or fluorescent agent instead of lubricating oil. The lubricator has an internal Venturi tube, and uses negative pressure generated when compressed air passes through the Venturi tube to suck out the test liquid and mix the mist of the test liquid into the compressed air.

[0031] The test liquid supplying device 10 of this embodiment is configured as described above. The method of use and operation of the test liquid supplying device 10 will be described below.

[0032] (When air is supplied from a factory) In this case, the test liquid supplying device 10 is connected to a piping system 80 as shown in Fig. 3, for example, and is used for leak testing of the piping system 80. The test liquid supplying device 10 operates by receiving a supply of compressed air from an air supplying system 82 in a factory or the like. The air supplying system 82 supplies clean compressed air from which dust and moisture have been removed to the test liquid supplying device 10. Therefore, in this case, the filter unit 22 (see Fig. 1) is removed from the test liquid supplying device 10, as shown in Fig. 4.

[0033] The piping system 80 in FIG. 3 has a plurality of couplings 86 connecting pipes 84 to each other. Each part of the piping system 80 is provided with a shutoff valve 88. Although not shown, couplings 86 are provided not only at the connection points between the pipes 84 but also at the connection points between the shutoff valves 88 and the pipes 84. The couplings 86 include, for example, connection points such as threaded joints, and connection points formed by welding, brazing, or the like. In the piping system 80, compressed air leaks may occur due to loosening of connections such as the couplings 86 and the shutoff valves 88. Furthermore, in the piping system 80, compressed air leaks may occur due to, for example, deterioration of the pipes 84 or the couplings 86. Periodic leak inspections are required to detect such compressed air leaks.

[0034] In the piping system 80, some shutoff valves 88 are open to supply compressed air containing the test liquid to the piping 84 to be inspected. The shutoff valves 88 shaded in black in the figure indicate that they are open. In addition, a second filter 90 is installed downstream of the piping system 80. The second filter 90 separates the mist-like test liquid from the compressed air and prevents the test liquid from scattering to the outside.

[0035] (Direct Pressure Operation) In the piping system 80 described above, the operation (direct pressure operation) of the test liquid supply device 10 when there is no compressed air remaining inside the piping 84 to be tested will be described. In this case, the first switching valve 24 of the test liquid supply device 10 is manually switched to the direct pressure position shown in FIG. 4 by an operator. In the direct pressure position, the first switching valve 24 connects the introduction flow path 34 and the first flow path 26, and the second flow path 28 connects the first exhaust section 44a. In the direct pressure operation, the fourth end 28b of the second flow path 28 is closed by the second switching valve 52.

[0036] The compressed air flowing in from the inlet port 20 flows into the first flow path 26 via the inlet flow path 34. The compressed air passes through the first check valve 46 of the first flow path 26 and flows out from the exhaust port 32. The compressed air flowing out from the exhaust port 32 passes through the mist supply unit 18. At this time, the mist supply unit 18 adds a mist of the test liquid to the compressed air. As described above, the test liquid supply device 10 supplies the compressed air directly to the piping system 80 through the first flow path 26 of the pressure supply unit 16 without increasing the pressure. In this case, the pressure supply unit 16 can supply a sufficient flow rate of compressed air to the piping system 80.

[0037] (Pressure Boosting Operation) Depending on the piping system 80 in the factory, it may be necessary to perform a leak inspection with compressed air remaining inside the piping 84. Therefore, the operation (pressure boosting operation) of the inspection liquid supply device 10 when compressed air remains inside the piping 84 to be inspected will be described.

[0038] In the pressure-increasing operation, the first switching valve 24 of the test solution supplying device 10 is manually switched to the pressure-increasing position shown in Fig. 5 by an operator. In the pressure-increasing position, the first switching valve 24 connects the introduction flow path 34 to the second flow path 28 and connects the second exhaust part 44b to the first flow path 26. Note that the first check valve 46 prevents compressed air from flowing back into the first flow path 26.

[0039] The compressed air that flows in from the inlet port 20 flows into the second flow path 28 via the inlet flow path 34. A portion of the compressed air is increased in pressure by the pressure increase valve 48. The compressed air increased in pressure by the pressure increase valve 48 is stored in the accumulator tank 50. The increased-pressure compressed air continues to be stored in the accumulator tank 50 while the second switching valve 52 is in the OFF position.

[0040] A portion of the compressed air that has flowed into the second flow path 28 flows into the pilot flow path 62. During the OFF period, the pilot flow path 62 is closed by the first time delay valve 64. Note that a portion of the compressed air in the pilot flow path 62 flows into the first control port 64c of the first time delay valve 64 via the third switching valve 68 as drive air for the first time delay valve 64. The pressure of the drive air for the first time delay valve 64 gradually increases.

[0041] 6 , when the first delay time set by the first throttle valve 72 has elapsed, the first time delay valve 64 switches to the open position, connecting the first portion 62a and the second portion 62b of the pilot flow path 62. This causes pilot air to be supplied to the second switching valve 52, which switches to the ON position. As a result, the system transitions to an ON period in which compressed air stored in the accumulator tank 50 is released from the discharge port 32. During the ON period, the mist supply unit 18 supplies a mist of test liquid to the compressed air released from the discharge port 32.

[0042] A portion of the pilot air in the second portion 62b of the pilot flow path 62 flows as drive air into the second control port 66c of the second time delay valve 66. During the ON period, the pressure of the drive air in the second time delay valve 66 gradually increases.

[0043] 7, when the second delay time set by the second throttle valve 72A elapses after the ON period begins, the fifth switching valve 70A of the second time delay valve 66 switches to the open position. As a result, the second time delay valve 66 supplies drive air from the first portion 62a of the pilot flow path 62 to the third switching valve 68. The third switching valve 68 switches to the second position. The drive air in the first time delay valve 64 is exhausted from the fourth exhaust portion 67B, and the fourth switching valve 70 returns to the closed position.

[0044] When the fourth switching valve 70 returns to the closed position, the pilot air is exhausted from the second switching valve 52. In addition, as the pilot air is exhausted from the second portion 62b, the drive air of the second time delay valve 66 is released.

[0045] As a result, as shown in FIG. 5 , the second switching valve 52 switches to the OFF position. The second switching valve 52 stops releasing compressed air from the accumulator tank 50 and enters the OFF period. The fifth switching valve 70A also returns to its initial position. When the fifth switching valve 70A returns to its initial position, the driving air of the third switching valve 68 is exhausted from the fifth exhaust portion 67C, and the third switching valve 68 returns to its first position. Thereafter, driving air is supplied to the first time delay valve 64 through the third switching valve 68.

[0046] 5 to 7, the timer circuit 54 repeats the operations described above, causing the test liquid supplying device 10 to intermittently supply compressed air and mist-like test liquid to the piping system 80. By supplying compressed air intermittently in this manner, it is possible to store compressed air at a sufficient pressure and volume in the accumulator tank 50, and to supply the pressurized compressed air at a sufficient flow rate to the piping system 80. Furthermore, because the test liquid supplying device 10 can perform the pressure boosting operation without receiving a power supply, it is possible to perform leak testing even in places where it is difficult to secure a power source.

[0047] (When air is not supplied from the factory) There are cases where clean compressed air cannot be supplied from the factory. In such cases, as shown in Figure 8, a filter unit 22 is attached to the inlet flow path 34 between the inlet port 20 and the first switching valve 24. In addition, a small air compressor (not shown) is connected to the inlet port 20. The first switching valve 24 is switched to the direct pressure position by the user.

[0048] Next, compressed air compressed by a small air compressor flows in from the inlet port 20. The compressed air compressed by the small air compressor contains dust and condensed water (liquid phase components). The filter unit 22 can supply clean compressed air by removing the dust and water contained in the compressed air.

[0049] The compressed air that has passed through the filter unit 22 passes through the pressure supply unit 16 via the first switching valve 24 and the first flow path 26 and is led to the mist supply unit 18. The mist supply unit 18 adds a mist of test liquid to the passing compressed air and supplies the compressed air containing the test liquid to the test object (e.g., the piping system 80 in FIG. 3). As described above, the test liquid supply device 10 of this embodiment can supply a mist of test liquid to the test object even when compressed air cannot be supplied from the factory.

[0050] The present invention is not limited to the above disclosure, and various configurations can be adopted without departing from the gist of the present invention.

[0051] In relation to the above disclosure, the following notes are further disclosed.

[0052] (Supplementary Note 1) One aspect of the disclosure is a test liquid supply device (10) including an inlet port (20) for introducing compressed air, an outlet port (32) for discharging the compressed air, a first flow path (26) communicating with the outlet port, a second flow path (28) arranged parallel to the first flow path and communicating with the outlet port, the second flow path (28) having a pressure booster valve (48) therethrough, a first switching valve (24) connecting either the first flow path or the second flow path to the inlet port, and a mist supply unit (18) for supplying mist-like test liquid to the compressed air discharged from the outlet port. With this test liquid supply device, if compressed air remains inside the test object, the test liquid can be supplied in mist-like form to the test object by boosting the compressed air through the second flow path and the pressure booster valve. Furthermore, if no compressed air remains inside the test object, the test liquid supply device can supply mist-like test liquid to the test object through the first flow path.

[0053] (Supplementary Note 2) The test liquid supply device described in Supplementary Note 1 may further include an accumulator tank (50) connected downstream of the booster valve, a second switching valve (52) connected downstream of the accumulator tank, closing the second flow path in an OFF position and connecting the second flow path to the discharge port in an ON position, and a timer circuit (54) that takes in pilot air for the second switching valve from the second flow path upstream of the booster valve, supplies the pilot air to the second switching valve during an ON period, and discharges the pilot air from the second switching valve during an OFF period. This test liquid supply device stores compressed air boosted by the booster valve in the accumulator tank and intermittently releases it, thereby supplying a sufficient flow rate of compressed air to the test subject and stabilizing the supply of mist-like test liquid.

[0054] (Supplementary Note 3) In the test liquid supply device described in Supplementary Note 2, the timer circuit may include: a pilot flow path (62) branching from the second flow path to supply the pilot air to the second switching valve; a first time delay valve (64) provided in the pilot flow path to adjust the OFF period; and a second time delay valve (66) driven by the pilot air supplied from the first time delay valve to adjust the ON period. With this test liquid supply device, it is possible to easily adjust the ON period during which compressed air stored in the accumulator tank is released and the OFF period during which compressed air is stored in the accumulator tank.

[0055] (Supplementary Note 4) The test liquid supplying device described in Supplementary Note 3 may further include a box-shaped housing (76) that houses the first switching valve, the booster valve, the pressure accumulator tank, the first time delay valve, and the second time delay valve, and one surface of the housing may have an operating section for the first switching valve, an operating section for the first time delay valve, an operating section for the second time delay valve, the inlet port, and the outlet port. This test liquid supplying device is excellent in portability and operability.

[0056] (Supplementary Note 5) The test liquid supply device described in any one of Supplementary Notes 1 to 4 may further include, between the inlet port and the first switching valve, a first filter (36) for removing dust and a dryer (42) for removing liquid phase components contained in the compressed air. This test liquid supply device can use compressed air supplied from a small air compressor for leak testing.

[0057] DESCRIPTION OF SYMBOLS 10... Test liquid supply device 16... Pressure supply unit 18... Mist supply unit 20... Inlet port 24... First switching valve 26... First flow path 28... Second flow path 32... Discharge port 36... First filter 42... Dryer 46... First check valve 48... Pressure booster valve 50... Pressure accumulator tank 52... Second switching valve 54... Timer circuit 62... Pilot flow path 64... First time delay valve 66... ​​Second time delay valve

Claims

1. An inspection liquid supply device (10) comprising: an introduction port (20) for introducing compressed air; a discharge port (32) for discharging the compressed air; a first flow path (26) communicating with the discharge port; a second flow path (28) arranged in parallel with the first flow path, communicating with the discharge port, and having a pressure increasing valve (48) therein; a first switching valve (24) connecting either one of the first flow path and the second flow path to the introduction port; and a mist supply unit (18) for supplying a mist-like inspection liquid to the compressed air discharged from the discharge port.

2. The inspection liquid supply device according to claim 1, further comprising: a pressure accumulation tank (50) connected downstream of the pressure increasing valve; a second switching valve (52) connected downstream of the pressure accumulation tank, closing the second flow path in the OFF position and communicating the second flow path with the discharge port in the ON position; and a timer circuit (54) taking in pilot air from the second flow path upstream of the pressure increasing valve, supplying the pilot air to the second switching valve during the ON period, and discharging the pilot air of the second switching valve during the OFF period.

3. The inspection liquid supply device according to claim 2, wherein the timer circuit comprises: a pilot flow path (62) branching from the second flow path and supplying the pilot air to the second switching valve; a first time delay valve (64) provided in the pilot flow path for adjusting the OFF period; and a second time delay valve (66) driven by the pilot air supplied from the first time delay valve for adjusting the ON period.

4. The inspection liquid supply device according to claim 3, further comprising a box-shaped housing (76) accommodating the first switching valve, the pressure increasing valve, the pressure accumulation tank, the first time delay valve, and the second time delay valve, and having, on one surface of the housing, an operation part of the first switching valve, an operation part of the first time delay valve, an operation part of the second time delay valve, the introduction port, and the discharge port.

5. The inspection liquid supply device according to any one of claims 1 to 4, further comprising, between the introduction port and the first switching valve, a first filter (36) for removing dust and a dryer (42) for removing the liquid phase component contained in the compressed air.

Images