Fixture for filter detection

Abstract

The utility model discloses a clamp for filter detection, which relates to the technical field of castings and comprises a bottom plate provided with a positioning component. The pushing assembly can push the clamping block, so that the clamping block can be pressed on the filter on the positioning assembly; one end of the first switching air pipe is sleeved with a sealing ring, the other end of the first switching air pipe is used for being communicated with the air inlet end of the flow detection device, the first switching air pipe is arranged on the clamping block, and one end of the first switching air pipe is inserted into a guide-out pipe on the filter; and one end of the second switching air pipe is used for being inserted into a guide-in pipe of the filter on the positioning assembly and can be in interference fit with the guide-in pipe of the filter, and the other end of the second switching air pipe is used for being communicated with the air outlet end of the pressurized air supply device. According to the clamp, the pressurization air supply device and the flow detection device can synchronously carry out air tightness detection and filtering performance detection, and the detection efficiency of the filter can be improved.

Description

Technical Field

[0001] The utility model relates to the technical field of leak detection, in particular to a clamp used for filter detection. Background Art

[0002] A filter is a device used to remove impurities or particles from a fluid. The filter usually includes a cylinder, an inlet pipe, a filter assembly, and an outlet pipe. The filter assembly is disposed in the cylinder, and the inlet pipe and the outlet pipe are both disposed on the cylinder. The fluid to be filtered flows into the cylinder through the inlet pipe. The filter assembly in the cylinder can filter the impurities or particles in the fluid. After filtration, the fluid flows out from the outlet pipe to complete the filtration of the fluid. Before installing the filter into the corresponding equipment, the filter needs to be tested. Common tests include filtration performance testing and air tightness testing.

[0003] The inspector will first place the filter to be tested on a special air tightness test fixture, and move the air tightness test fixture and the filter into the water tank together. Then the pressurized air supply device will fill the filter with gas for air tightness test. After the air tightness test is completed, the inspector will move the air tightness test fixture and the filter out of the water tank, remove the filter from the air tightness test fixture, and then place the filter on a special flow test fixture. After the flow test fixture clamps the filter, the inspector will move the flow test fixture and the filter into the flow test device for filtration performance testing to complete the filter test. This filter testing method requires moving the fixture back and forth and repeatedly clamping the filter, which is not conducive to improving the filter testing efficiency. Utility Model Content

[0004] The utility model aims to solve at least one of the technical problems existing in the prior art. To this end, the utility model provides a clamp for filter detection, which is conducive to improving the detection efficiency of the filter.

[0005] The clamp for filter detection according to the embodiment of the utility model comprises:

[0006] A bottom plate, wherein a positioning assembly is provided on the bottom plate, and the positioning assembly is used for positioning the filter;

[0007] A clamping block and a pushing assembly, wherein the clamping block is slidably connected to the bottom plate, the pushing assembly is disposed on the bottom plate, and the pushing assembly can push the clamping block toward the direction close to the positioning assembly, so that the clamping block can be pressed on the filter on the positioning assembly and the filter is fixed on the positioning assembly;

[0008] A first adapter air pipe, one end of which is sleeved with a sealing ring, the other end of which is used to communicate with the air inlet end of the flow detection device, the first adapter air pipe is arranged on the clamping block, so that when the clamping block is pressed against the filter, one end of the first adapter air pipe is inserted into the outlet pipe on the filter, and the first adapter air pipe is pressed against the inner wall of the outlet pipe on the filter through the sealing ring;

[0009] A second adapter air pipe, the second adapter air pipe is arranged on the base plate, one end of the second adapter air pipe is used to be inserted into the inlet pipe of the filter on the positioning assembly, and can be interference fit with the inlet pipe of the filter, and the other end of the second adapter air pipe is used to be connected to the air outlet end of the pressurized air supply device, so that the gas generated by the pressurized air supply device can pass through the second adapter air pipe, the filter and the first adapter air pipe in sequence and flow into the flow detection device.

[0010] At least the following beneficial effects are achieved:

[0011] When the filter needs to be tested, the tester can place the filter to be tested on the positioning assembly. The positioning assembly plays a positioning role so that the filter can be in the correct posture. Then the tester can insert one end of the second adapter air pipe into the inlet pipe of the filter on the positioning assembly. The other end of the second adapter air pipe is used to communicate with the air outlet end of the pressurized air supply device. The second adapter air pipe and the inlet pipe on the filter are interference fit, that is, the gap between the second adapter air pipe and the inner wall of the inlet pipe is closed. Then the tester manipulates the pushing assembly so that the pushing assembly pushes the clamping block in the direction close to the positioning assembly. Under the pushing action of the pushing assembly, the clamping block presses against the filter on the positioning assembly, so that the filter is fixed on the positioning assembly, that is, the clamping block and the positioning assembly clamp the filter. In the process of the clamping block approaching the filter on the positioning assembly, the first adapter air pipe on the clamping block will also approach the filter. When the clamping block is pressed against the filter, one end of the first adapter air pipe is inserted into the outlet pipe on the filter, and the other end of the first adapter air pipe is used to connect with the air inlet end of the flow detection device. The first adapter air pipe is pressed against the inner wall of the outlet pipe on the filter through the sealing ring, that is, the sealing ring seals the gap between the first adapter air pipe and the inner wall of the outlet pipe.

[0012] After completing the above steps, the inspector immerses the clamp and the filter in the water in the water tank and starts them. The gas generated by the pressurized air supply device can pass through the second adapter air pipe and quickly fill the filter. When the inspector observes that the water in the water tank is bubbling, it means that the filter is leaking, which means that the air tightness test of the filter has failed. When the inspector observes that there are no bubbles in the water in the water tank, it means that there is no leakage in the filter, which means that the air tightness test of the filter has passed. At the same time, the gas generated by the pressurized air supply device can pass through the second adapter air pipe, the filter and the first adapter air pipe and enter the flow detection device. The flow detection device can detect the flow parameters of the inflowing gas and derive the filtering performance of the filter. After the test is completed, the inspector can move the clamp and the filter out of the water tank together, and then push the assembly to drive the clamping block away from the positioning assembly, so that the clamping block releases the filter, and the inspector can remove the filter. It can be seen that the fixture for filter testing in the embodiment of the utility model can enable the pressurized air supply device and the flow detection device to simultaneously perform air tightness testing and filtration performance testing, thereby avoiding the need for testing personnel to carry the fixture back and forth and repeatedly clamp the filter, which is beneficial to improving the detection efficiency of the filter.

[0013] According to the clamp for filter detection in the embodiment of the utility model, the positioning assembly includes a positioning block, a first positioning groove is formed on a side of the positioning block facing the clamping block, and an inner wall of the first positioning groove is used to abut against the filter.

[0014] According to the clamp for filter detection in the embodiment of the utility model, a second positioning groove is formed on the side of the clamping block facing the positioning assembly, and the inner wall of the second positioning groove is used to abut against the filter.

[0015] According to the embodiment of the utility model, the clamp for filter detection also includes a support, a guide block and a plurality of guide rods, the support is arranged on the base plate, the guide block is arranged on the support, a plurality of guide holes are opened on the guide block, one end of the plurality of guide rods are connected to the clamping block, and the other ends of the plurality of guide rods are respectively passed through the plurality of guide holes.

[0016] According to the clamp for filter detection according to the embodiment of the utility model, the pushing assembly includes an articulated seat, a bending arm, a pulling rod, a push rod, a first hinge, a second hinge and a third hinge. The articulated seat is arranged on the support, and an avoidance hole is opened on the guide block. The push rod is passed through the avoidance hole. One end of the push rod is connected to the clamping block, and one end of the bending arm is hinged to the other end of the push rod through the first hinge. The other end of the bending arm and one end of the pull rod are both hinged to the articulated seat through the second hinge. The pull rod is connected to the bending arm through the third hinge, so that when the other end of the pull rod swings toward the direction close to the positioning assembly, the push rod pushes the clamping block toward the direction close to the positioning assembly.

[0017] According to the clamp for filter detection in the embodiment of the utility model, the pushing assembly further includes a holding portion, and the holding portion is arranged on the other end of the pull rod.

[0018] According to the embodiment of the utility model, the fixture for filter detection also includes a mounting block and a fastener, wherein the mounting block is arranged on the base plate, a mounting hole is provided on the mounting block, a threaded hole connected to the mounting hole is provided on the mounting block, the second adapter air pipe is passed through the mounting hole, the fastener is threadedly connected to the inner wall of the threaded hole, and one end of the fastener can be pressed against the second adapter air pipe to fix the second adapter air pipe on the inner wall of the mounting hole.

[0019] According to the clamp for filter detection in the embodiment of the utility model, a plurality of annular grooves are opened on one end of the first adapter air pipe, and the number of the sealing rings is multiple, and the multiple sealing rings are respectively sleeved on the multiple annular grooves.

[0020] According to the clamp for filter testing in the embodiment of the utility model, a guide chamfer is provided at one end of the second adapter air pipe.

[0021] Additional aspects and advantages of the present invention will be given in part in the following description, and in part will become apparent from the following description, or will be learned through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The present invention is further described below with reference to the accompanying drawings and embodiments, wherein:

[0023] Figure 1 This is a schematic diagram of the structure of the filter of the embodiment of the utility model;

[0024] Figure 2 This is a schematic diagram of the structure of a fixture and a filter used for filter detection according to an embodiment of the utility model;

[0025] Figure 3 This is a schematic diagram of the structure of a fixture for filter detection according to an embodiment of the utility model;

[0026] Figure 4 for Figure 3 A partial enlarged view of the middle A;

[0027] Figure 5 for Figure 3 A partial enlarged view of point B in the middle;

[0028] Figure 6 This is a schematic structural diagram of a first adapter air pipe in a fixture for filter detection according to an embodiment of the utility model;

[0029] Figure 7 This is a schematic structural diagram of a second adapter air pipe in a fixture for filter detection according to an embodiment of the utility model;

[0030] Reference numerals:

[0031] Base plate 100; positioning assembly 110; positioning block 111; first positioning groove 112; mounting block 120; mounting hole 121; threaded hole 122; first adapter air pipe 130; sealing ring 131; second adapter air pipe 140; guide chamfer 141; clamping block 150; second positioning groove 151; support 160; guide block 170; avoidance hole 171; guide rod 180;

[0032] Pushing assembly 200 ; hinged seat 210 ; bending arm 220 ; pull rod 230 ; gripping portion 231 ; push rod 240 ; first hinge 250 ; second hinge 260 ; third hinge 270 . DETAILED DESCRIPTION

[0033] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0034] In the description of the present invention, it should be understood that descriptions involving orientation, such as up, down, front, back, left, right, etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0035] In the description of the present utility model, "a plurality" means more than two. If there is a description of "first" or "second", it is only for the purpose of distinguishing the technical features, and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0036] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0037] refer to Figures 1 to 3 The clamp for filter detection of the embodiment of the utility model comprises:

[0038] A bottom plate 100, on which a positioning assembly 110 is disposed, and the positioning assembly 110 is used to position the filter;

[0039] The clamping block 150 and the pushing assembly, the clamping block 150 is slidably connected to the bottom plate 100, the pushing assembly is arranged on the bottom plate 100, and the pushing assembly can push the clamping block 150 toward the direction close to the positioning assembly 110, so that the clamping block 150 can be pressed on the filter on the positioning assembly 110, and the filter is fixed on the positioning assembly 110;

[0040] A first adapter air pipe 130, one end of which is sleeved with a sealing ring 131, and the other end of which is used to communicate with the air inlet end of the flow detection device. The first adapter air pipe 130 is arranged on the clamping block 150, so that when the clamping block 150 is pressed against the filter, one end of the first adapter air pipe 130 is inserted into the outlet pipe on the filter, and the first adapter air pipe 130 is pressed against the inner wall of the outlet pipe on the filter through the sealing ring 131;

[0041] The second adapter air pipe 140 is arranged on the base plate 100, one end of the second adapter air pipe 140 is used to be inserted into the inlet pipe of the filter on the positioning assembly 110, and can be interference fit with the inlet pipe of the filter, and the other end of the second adapter air pipe 140 is used to be connected to the air outlet end of the pressurized air supply device, so that the gas generated by the pressurized air supply device can pass through the second adapter air pipe 140, the filter and the first adapter air pipe 130 in sequence and flow into the flow detection device.

[0042] It is understandable that when the filter needs to be tested, the tester can place the filter to be tested on the positioning assembly 110. The positioning assembly 110 plays a positioning role so that the filter can be in the correct posture. Then the tester can insert one end of the second adapter air pipe 140 into the inlet pipe of the filter on the positioning assembly 110. The other end of the second adapter air pipe 140 is used to communicate with the air outlet end of the pressurized air supply device. The second adapter air pipe 140 and the inlet pipe on the filter are interference fit, that is, the gap between the second adapter air pipe 140 and the inner wall of the inlet pipe is closed. Then the tester manipulates the pushing assembly so that the pushing assembly pushes the clamping block 150 in the direction close to the positioning assembly 110. Under the pushing action of the pushing assembly, the clamping block 150 presses against the filter on the positioning assembly 110, so that the filter is fixed on the positioning assembly 110, that is, the clamping block 150 and the positioning assembly 110 clamp the filter. When the clamping block 150 approaches the filter on the positioning assembly 110, the first adapter air pipe 130 on the clamping block 150 also approaches the filter. When the clamping block 150 is pressed against the filter, one end of the first adapter air pipe 130 is inserted into the outlet pipe on the filter, and the other end of the first adapter air pipe 130 is used to communicate with the air inlet end of the flow detection device. The first adapter air pipe 130 is pressed against the inner wall of the outlet pipe on the filter through the sealing ring 131, that is, the sealing ring 131 seals the gap between the first adapter air pipe 130 and the inner wall of the outlet pipe.

[0043] After the above steps are completed, the inspector immerses the clamp and the filter in the water in the water tank and starts them. The gas generated by the pressurized air supply device can pass through the second adapter air pipe 140 and quickly fill the filter. When the inspector observes that the water in the water tank is bubbling, it means that the filter is leaking, which means that the air tightness test of the filter has failed. When the inspector observes that there are no bubbles in the water in the water tank, it means that there is no leakage in the filter, which means that the air tightness test of the filter has passed. At the same time, the gas generated by the pressurized air supply device can pass through the second adapter air pipe 140, the filter and the first adapter air pipe 130 and enter the flow detection device. The flow detection device can detect the flow parameters of the inflowing gas and derive the filtering performance of the filter. After the test is completed, the inspector can move the clamp and the filter out of the water tank together, and then push the assembly to drive the clamping block 150 away from the positioning assembly 110, so that the clamping block 150 releases the filter, and the inspector can remove the filter. It can be seen that the fixture for filter testing in the embodiment of the utility model can enable the pressurized air supply device and the flow detection device to simultaneously perform air tightness testing and filtration performance testing, thereby avoiding the need for testing personnel to carry the fixture back and forth and repeatedly clamp the filter, which is beneficial to improving the detection efficiency of the filter.

[0044] It should be explained that the pressurized gas supply device can provide gas with stable pressure. The pressurized gas supply device can be an air pump. When the gas passes through the filter and enters the flow detection device, the pressure and flow rate of the gas will change under the action of the filter. The flow detection device can detect the flow rate, pressure, temperature and flow rate of the inflowing gas. By detecting these parameters, the filtering performance of the filter can be obtained. If the filter is clogged, the airflow through the filter will be unstable, which will cause the reading of the flow detection device to fluctuate. By detecting the stability of the gas flow, the working condition and filtering performance of the filter can be evaluated.

[0045] refer to Figure 6 , a plurality of annular grooves are provided on one end of the first adapter air pipe 130, and a plurality of sealing rings 131 are provided, and the plurality of sealing rings 131 are respectively sleeved on the plurality of annular grooves. It can be understood that the annular grooves can play a positioning role for the sealing rings 131. On the other hand, a plurality of sealing rings 131 are sleeved on one end of the first adapter air pipe 130, and the plurality of sealing rings 131 can ensure the airtightness between the first adapter air pipe 130 and the filter, so as to ensure the accuracy of the filtration performance test and the airtightness test of the filter.

[0046] refer to Figure 3 The positioning assembly 110 includes a positioning block 111. A first positioning groove 112 is provided on the side of the positioning block 111 facing the clamping block 150. The inner wall of the first positioning groove 112 is used to abut against the filter. A second positioning groove 151 is provided on the side of the clamping block 150 facing the positioning assembly 110. The inner wall of the second positioning groove 151 is used to abut against the filter. It can be understood that the first positioning groove 112 on the positioning block 111 and the second positioning groove 151 on the clamping block 150 can both play a positioning role on the filter. Specifically, the inner wall of the first positioning groove 112 and the inner wall of the second positioning groove 151 are both used to clamp the filter.

[0047] refer to Figure 3 The fixture for filter detection also includes a support 160, a guide block 170 and a plurality of guide rods 180. The support 160 is arranged on the bottom plate 100, the guide block 170 is arranged on the support 160, a plurality of guide holes are opened on the guide block 170, one end of the plurality of guide rods 180 are connected to the clamping block 150, and the other ends of the plurality of guide rods 180 are respectively penetrated into the plurality of guide holes. It can be understood that the clamping block 150 is slidably connected to the guide block 170 through the plurality of guide rods 180. The plurality of guide rods 180 play a role in guiding and supporting the movement of the clamping block 150, so that the clamping block 150 can move smoothly.

[0048] refer to Figure 3 and Figure 4The pushing assembly includes an articulated seat 210, a bending arm 220, a pull rod 230, a push rod 240, a first hinge 250, a second hinge 260 and a third hinge 270. The articulated seat 210 is arranged on the support 160, and an avoidance hole 171 is opened on the guide block 170. The push rod 240 is penetrated into the avoidance hole 171. One end of the push rod 240 is connected to the clamping block 150, and one end of the bending arm 220 is hinged to the other end of the push rod 240 through the first hinge 250. The other end of the bending arm 220 and one end of the pull rod 230 are both hinged to the articulated seat 210 through the second hinge 260. The pull rod 230 is connected to the bending arm 220 through the third hinge 270, so that when the other end of the pull rod 230 swings in the direction away from the positioning assembly 110, the push rod 240 pushes the clamping block 150 in the direction close to the positioning assembly 110. The pushing assembly further includes a gripping portion 231 , which is disposed on the other end of the pull rod 230 .

[0049] It is understandable that when the filter needs to be clamped, the inspector can hold the gripping portion 231 and manipulate the pull rod 230 to swing the pull rod 230 toward the direction close to the positioning assembly 110. Under the pulling action of the pull rod 230, the bending arm 220 begins to move toward the direction close to the positioning assembly 110, so that the bending arm 220 drives the push rod 240 toward the direction close to the positioning assembly 110, and then the push rod 240 drives the clamping block 150 to push the clamping block 150 toward the direction close to the positioning assembly 110. When the filter needs to be loosened, the inspector can hold the gripping portion 231 and manipulate the pull rod 230 to swing the pull rod 230 toward the direction away from the positioning assembly 110. Under the pulling action of the pull rod 230, the bending arm 220 begins to move in the direction away from the positioning assembly 110, so that the bending arm 220 drives the push rod 240 to move in the direction closer to the positioning assembly 110, and then the push rod 240 drives the clamping block 150 to pull the clamping block 150 in the direction away from the positioning assembly 110.

[0050] Specifically, the first hinge 250, the second hinge 260 and the third hinge 270 can be the first hinge shaft, the second hinge shaft and the third hinge shaft respectively, and the first hinge shaft, the second hinge shaft and the third hinge shaft are parallel to each other. One end of the bending arm 220 is rotatably connected to the other end of the push rod 240 through the first hinge shaft, the other end of the bending arm 220 and one end of the pull rod 230 are rotatably connected to the hinge seat 210 through the second hinge shaft, and the pull rod 230 is rotatably connected to the bending arm 220 through the third hinge shaft.

[0051] refer to Figure 3 and Figure 5The fixture for filter detection also includes a mounting block 120 and a fastener. The mounting block 120 is arranged on the bottom plate. A mounting hole 121 is provided on the mounting block 120. A threaded hole 122 connected to the mounting hole 121 is provided on the mounting block 120. The second adapter air pipe 140 is inserted into the mounting hole 121. The fastener is threadedly connected to the inner wall of the threaded hole 122. One end of the fastener can be pressed against the second adapter air pipe 140 so that the second adapter air pipe 140 is fixed on the inner wall of the mounting hole 121. It can be understood that the fastener can be a bolt. When the second adapter air pipe 140 needs to be inserted into the guide pipe on the filter pipe, the inspector can first loosen the bolt, and one end of the bolt can be separated from the contact with the second adapter air pipe 140. At this time, the inspector can rotate or move the second adapter air pipe 140 to adjust the posture of the second adapter air pipe 140, so that the inspector can smoothly insert the second adapter air pipe 140 into the guide pipe of the filter. After the second adapter air pipe 140 is inserted, the inspector can tighten the bolts again to prevent the second adapter air pipe 140 from loosening during the inspection process. Figure 7 On the other hand, a guide chamfer 141 is provided at one end of the second adapter air pipe 140, and the guide chamfer 141 enables the inspector to more smoothly insert the second adapter air pipe 140 into the filter inlet pipe.

[0052] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0053] Of course, the present invention is not limited to the above-mentioned embodiments, and technicians familiar with the field may make equivalent modifications or substitutions without violating the spirit of the present invention. These equivalent modifications or substitutions are all included in the scope defined by the claims of this application.

Claims

1. A fixture for filter testing, characterized in that: include: A bottom plate, wherein a positioning assembly is provided on the bottom plate, and the positioning assembly is used for positioning the filter; A clamping block and a pushing assembly, wherein the clamping block is slidably connected to the bottom plate, the pushing assembly is disposed on the bottom plate, and the pushing assembly can push the clamping block toward the direction close to the positioning assembly, so that the clamping block can be pressed on the filter on the positioning assembly and the filter is fixed on the positioning assembly; A first adapter air pipe, one end of which is sleeved with a sealing ring, the other end of which is used to communicate with the air inlet end of the flow detection device, the first adapter air pipe is arranged on the clamping block, so that when the clamping block is pressed against the filter, one end of the first adapter air pipe is inserted into the outlet pipe on the filter, and the first adapter air pipe is pressed against the inner wall of the outlet pipe on the filter through the sealing ring; A second adapter air pipe, the second adapter air pipe is arranged on the base plate, one end of the second adapter air pipe is used to be inserted into the inlet pipe of the filter on the positioning assembly, and can be interference fit with the inlet pipe of the filter, and the other end of the second adapter air pipe is used to be connected to the air outlet end of the pressurized air supply device, so that the gas generated by the pressurized air supply device can pass through the second adapter air pipe, the filter and the first adapter air pipe in sequence and flow into the flow detection device.

2. The fixture for filter detection according to claim 1, characterized in that: The positioning assembly comprises a positioning block, and a first positioning groove is formed on a side of the positioning block facing the clamping block, and an inner wall of the first positioning groove is used to abut against the filter.

3. The fixture for filter testing according to claim 1, characterized in that: A second positioning groove is formed on one side of the clamping block facing the positioning assembly, and an inner wall of the second positioning groove is used to abut against the filter.

4. The fixture for filter testing according to claim 1, characterized in that: It also includes a support, a guide block and multiple guide rods, the support is arranged on the base plate, the guide block is arranged on the support, multiple guide holes are opened on the guide block, one end of the multiple guide rods is connected to the clamping block, and the other ends of the multiple guide rods are respectively inserted into the multiple guide holes.

5. The fixture for filter testing according to claim 4, characterized in that: The pushing assembly includes an articulated seat, a bending arm, a pulling rod, a push rod, a first hinge, a second hinge and a third hinge. The articulated seat is arranged on the support, and an avoidance hole is opened on the guide block. The push rod is inserted into the avoidance hole, one end of the push rod is connected to the clamping block, one end of the bending arm is hinged to the other end of the push rod through the first hinge, the other end of the bending arm and one end of the pull rod are both hinged to the articulated seat through the second hinge, and the pull rod is connected to the bending arm through the third hinge, so that when the other end of the pull rod swings toward the direction close to the positioning assembly, the push rod pushes the clamping block toward the direction close to the positioning assembly.

6. The fixture for filter testing according to claim 5, characterized in that: The pushing assembly further comprises a gripping portion, and the gripping portion is arranged on the other end of the pull rod.

7. The fixture for filter testing according to claim 1, characterized in that: It also includes a mounting block and a fastener, wherein the mounting block is arranged on the base plate, a mounting hole is provided on the mounting block, a threaded hole connected to the mounting hole is provided on the mounting block, the second adapter air pipe is passed through the mounting hole, the fastener is threadedly connected to the inner wall of the threaded hole, and one end of the fastener can be pressed against the second adapter air pipe to fix the second adapter air pipe on the inner wall of the mounting hole.

8. The fixture for filter testing according to claim 1, characterized in that: A plurality of annular grooves are formed on one end of the first adapter air pipe, and a plurality of sealing rings are provided. The plurality of sealing rings are respectively sleeved on the plurality of annular grooves.

9. The fixture for filter testing according to claim 1, characterized in that: One end of the second adapter air pipe is provided with a guide chamfer.

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