Special-shaped piece low-pressure airtightness detection device and airtightness detection method

Abstract

The invention discloses a special-shaped piece low-pressure airtightness detection device, which comprises a fixed base connected with a workbench, the fixed base is provided with a special-shaped piece fixing seat and a three-way fixing block, and the left end and the right end of the three-way fixing block are respectively connected with the special-shaped piece fixing seat and a vacuum pump through an air compressor hose. And the other end of the three-way fixed block is connected with a precision pressure gauge. The testing device has the advantage of testing the sealing performance of a large batch of special-shaped workpieces, the testing device can be improved according to actual production workpiece requirements, and the air tightness of products in different shapes is tested; and meanwhile, immersion in water is not needed, so that the problems of poor storability and the like caused by incapability of predicting aging and loss of the material after the surface of the workpiece is in contact with water are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of airtightness detection, and particularly to a low-pressure airtightness detection device and an airtightness detection method for special-shaped parts. Background Art

[0002] After assembling a certain nozzle assembly, it is necessary to detect its airtightness. To ensure the sealing performance and strength of such workpieces, a sealing test is usually required.

[0003] Generally, for the detection test of airtightness, most use the water tightness test. By slowly putting the assembly into water and observing whether there are bubbles generated and whether there are water droplets infiltrating into the interior of the assembly to judge its airtightness, the test cycle is long, and the test efficiency of the product is low, making it difficult to meet the production requirements of a large number of workpieces that meet the airtightness test.

[0004] In addition, for the workpieces that have undergone the water tightness test, it is impossible to predict the aging and loss of the material after its surface comes into contact with water, resulting in problems such as poor storage performance. Summary of the Invention

[0005] In view of this, the present invention proposes a low-pressure airtightness detection device and an airtightness detection method for special-shaped parts.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] A low-pressure airtightness detection device for special-shaped parts, a fixed base connected to a workbench, an irregular part fixing seat and a three-way connection fixing block are arranged on the fixed base, the left and right ends of the three-way connection fixing block are respectively connected to the irregular part fixing seat and a vacuum pump through air compressor hoses, and the other end of the three-way connection fixing block is connected to a precision pressure gauge.

[0008] As a further improvement of the above technical solution:

[0009] Preferably, the three-way connection block and the air compressor hose are connected through a double external thread ball valve.

[0010] Preferably, an internal thread pneumatic quick connector is arranged on one end of the double external thread ball valve connected to the vacuum pump.

[0011] Preferably, the connection end of the precision pressure gauge and both ends of any one of the air compressor hoses are wound with raw material tape.

[0012] Preferably, a silicone rubber layer is coated on the raw material tape.

[0013] Preferably, the fixed base is in a "J" shape, the irregular part fixing seat is arranged on the raised platform of the fixed base, and the three-way connection fixing block is arranged on one side of the raised platform of the fixed base.

[0014] Preferably, the upper opening of the special-shaped component fixing seat is threaded, and a rubber gasket is provided at the inner bottom of the opening of the special-shaped component fixing seat.

[0015] The present invention also provides an airtightness detection method using a low-pressure airtightness detection device for a special-shaped part, comprising the following steps:

[0016] Step 1. Conduct a sealing test on the entire device;

[0017] Step 2, connect the workpiece to be tested to the special-shaped part fixing seat through threads, and screw until there is no gap between the workpiece and the special-shaped part fixing seat;

[0018] Step 3. Open the double outer thread ball valves at both ends of the three-way fixed block to facilitate the gas extraction outside the device to form a pressure difference;

[0019] Step 4. Start the vacuum pump. When the value displayed on the precision pressure gauge reaches the required range, close the double outer thread ball valve connected to one end of the vacuum pump to stop extracting the gas in the device.

[0020] Step 5. Observe the changes in the value of the precision pressure gauge. If there is no change within 3 seconds, it means that the air tightness of the workpiece meets the requirements, and the air tightness test of the workpiece is completed.

[0021] As a further improvement of the above technical solution:

[0022] The step 1 includes the following steps:

[0023] Stpe11. First check whether the air compressor hose is damaged or leaking to ensure that there will be no leakage during the test;

[0024] Stpe12, check whether the double external thread ball valve and three-way fixing block, internal thread pneumatic quick connector and double external thread ball valve, three-way fixing block and precision pressure gauge are tightened to ensure the air tightness of the device;

[0025] Stpe13. Check whether the precision pressure gauge can work normally, determine whether the range selection is suitable for the workpiece to be measured, and adjust the precision pressure gauge to zero.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] 1. The testing device of the present invention has the advantage of being able to perform airtightness tests on large quantities of special-shaped workpieces. The testing device can be improved according to the actual production needs of workpieces to test the airtightness of products of different shapes. At the same time, it does not need to be immersed in water, so there is no problem of unpredictable aging and loss of materials after the workpiece surface comes into contact with water, resulting in poor storage performance.

[0028] 2. The main body structure design of the present invention is simple and the materials are easy to obtain, which reduces the complexity of the process of testing the sealing of the workpiece, can greatly shorten the time of product testing, and at the same time can reduce the loss of workpiece materials, effectively improving the efficiency of product internal pressure testing.

[0029] 3. The present invention provides a flexible and efficient air tightness testing method. By replacing the external connection device, air evacuation and air inflation can be achieved, low pressure and high pressure can be formed in the device, and high pressure / low pressure air tightness detection can be realized for special-shaped parts. High / low pressure detection can be selected according to the actual application scenario of the workpiece. This testing method is simple to operate and improves the overall efficiency of product sealing testing. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic diagram of the overall front view structure of the present invention;

[0031] Figure 2 It is a side view structural schematic diagram of the present invention;

[0032] Figure 3 It is a schematic diagram of the top view structure of the fixed base of the present invention.

[0033] In the figure: 1. Precision pressure gauge; 2. Double external thread ball valve; 3. Three-way fixing block; 4. Fixed base; 5. Air compressor hose; 6. Special-shaped part fixing seat; 7. Internal thread pneumatic quick connector; 8. Rubber gasket. DETAILED DESCRIPTION

[0034] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0035] In the description of the present invention, unless otherwise specified, "plurality" means two or more than two; the orientations or positional relationships indicated by the terms "upper", "lower", "left", "right", "inner", "outer", "front end", "rear end", "head", "tail", etc. are based on the orientations or positional relationships shown in the 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 operate in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", "third", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0036] In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "connected" and "connected to" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0037] As shown in the Figure 1 accompanying drawings, the technical solution of the present invention consists of the following components: precision pressure gauge 1, double external thread ball valve 2, three-way connection fixed block 3, fixed base 4, air compressor hose 5, special-shaped part fixed seat 6, internal thread pneumatic quick connector 7, rubber gasket 8, vacuum pump (not shown in the figure). For the double external thread ball valve 2, a 4-point double external thread ball valve 2 is used. For the internal thread pneumatic quick connector 7, a 4-point internal thread straight-through PCF-10 pneumatic quick connector is used. For the vacuum pump, a rotary vane vacuum pump is used.

[0038] As Figure 1 shown in the accompanying drawings, one end of the three-way connection fixed block 3 is installed with a precision pressure gauge 1, and the other two ends are respectively connected to the vacuum pump and the special-shaped part fixed seat 6 through the air compressor hose 5 and the double external thread ball valve 2 (the test workpiece is directly installed on the airtight working mechanism);

[0039] The end connected to the vacuum pump is connected with an internal thread pneumatic quick connector 7. The joints at each end are wrapped with raw material tape and then tightened. When necessary, 414 silicone rubber is spot-coated and cured for 24 hours to ensure the airtightness of the device. The three-way connection fixed block 3 is welded to the fixed base 4, and the welding slag and surface oil stains need to be treated. At the same time, the fixed base 4 is in a "J" shape, the special-shaped part fixed seat 6 is installed at the protruding end, and the three-way connection fixed block 3 is installed at the horizontal position on the side of the protruding end.

[0040] As Figure 1 shown in the accompanying drawings, the entire fixed base 4 is machined from 45# steel, the surface is blued, plate welding is allowed, the sharp edges are chamfered, and the surface is treated for removing welding slag and oil stains.

[0041] Both ends of the fixed base 4 are fixed to the corresponding workbench in the workshop with 4 M16×65 bolts.

[0042] As shown in the Figure 3 accompanying drawings, the special-shaped part fixed seat 6 is connected to the test workpiece by thread. In order to ensure that there is no air leakage at the connection, multiple rubber gaskets 8 are added at the lower end of the thread to ensure the airtightness of the connection.

[0043] In addition, the structure and shape of the special-shaped part fixed seat 6 can be changed according to different special-shaped parts to complete the airtightness detection of different types of workpieces.

[0044] As Figure 2 As shown, the three-way fixing block 3 has one end connected to the vacuum pump through the air compressor hose 5, and the other end connected to the air-shaped part fixing seat 6 through the air compressor hose 5. Both ends are connected to the double-outer-thread ball valve 2 for controlling the air pressure in the device, and one end is connected to the precision pressure gauge 1. The air tightness of the workpiece can be judged by observing the value changes of the precision pressure gauge 1.

[0045] When processing the three-way fixed block 3, it is necessary to perform a bluing treatment on the surface, a blunting treatment on the sharp edges and a surface degreasing treatment.

[0046] The use process of the present invention:

[0047] The use of this special-shaped parts sealing test device is specifically divided into two major steps: one is to test the sealing of the device itself before testing; the other is to test the sealing of the test workpiece.

[0048] When testing the leak tightness of the device before testing:

[0049] 1) First check whether the air compressor hose 5 is damaged or leaking to ensure that there will be no leakage during the test;

[0050] 2) Check whether the 4-point double external thread ball valve 2 and the three-way fixing block 3, the 4-point internal thread straight-through PCF-10 pneumatic quick connector and the 4-point double external thread ball valve 2, and the three-way fixing block 3 and the precision pressure gauge 1 are tightened to ensure the air tightness of the device;

[0051] 3) Check whether the precision instrument can work normally, determine whether the range selection is suitable for the workpiece to be measured, and adjust the precision instrument to zero.

[0052] When the workpiece is tested for tightness,

[0053] 1) Pass the workpiece to be tested through the airtightness detection device through the threaded connection nozzle, and rotate it until there is no gap between the workpiece and the device;

[0054] 2) Open the 4-point double outer thread ball valve 2 at both ends of the three-way fixed block 3 to facilitate the gas extraction outside the device to form a pressure difference;

[0055] 3) Start the rotary vane vacuum pump. When the value displayed on the precision pressure gauge 1 reaches the required range, close the valve connected to one end of the rotary vane vacuum pump and stop extracting the gas in the device;

[0056] 4) Observe the value change of precision pressure gauge 1. If there is no change within 3 seconds, it means that the air tightness of the workpiece meets the requirements, and the air tightness test of one workpiece is completed.

[0057] The above are only preferred specific implementation modes of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical solutions and inventive concepts of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A low-pressure airtightness detection device for special-shaped parts, characterized in that: A fixed base (4) connected to the workbench, an irregular part fixing seat (6) and a triple-connection fixing block (3) are arranged on the fixed base (4), the left and right ends of the triple-connection fixing block (3) are respectively connected to the irregular part fixing seat (6) and the vacuum pump through an air compressor hose (5), and the other end of the triple-connection fixing block (3) is connected to a precision pressure gauge (1).

2. The low-pressure airtightness detection device for special-shaped parts according to claim 1, characterized in that: The triple-connection connecting block and the air compressor hose (5) are connected through a double external thread ball valve (2).

3. The low-pressure airtightness detection device for special-shaped parts according to claim 2, characterized in that: An internal thread pneumatic quick connector (7) is arranged on one end double external thread ball valve (2) connected to the vacuum pump.

4. The low-pressure airtightness detection device for special-shaped parts according to claim 1, characterized in that: Sealing tapes are wound around both ends of the connection end of the precision pressure gauge (1) and any one of the air compressor hoses (5).

5. The low-pressure airtightness detection device for special-shaped parts according to claim 4, characterized in that: A silicone rubber layer is coated on the sealing tape.

6. The low-pressure airtightness detection device for special-shaped parts according to claim 1, characterized in that: The fixed base (4) is in a "C" shape, the irregular part fixing seat (6) is arranged on the raised platform of the fixed base (4), and the triple-connection fixing block (3) is arranged on one side of the raised platform of the fixed base (4).

7. The low-pressure airtightness detection device for special-shaped parts according to claim 1, characterized in that: The upper end opening of the irregular part fixing seat (6) is in a threaded shape, and a rubber gasket (8) is arranged at the inner bottom of the opening of the irregular part fixing seat (6).

8. An airtightness detection method using a low-pressure airtightness detection device for special-shaped parts, characterized in that: It includes the following steps: Step1. Conduct a sealing test on the whole device; Step2. Connect the workpiece to be tested to the irregular part fixing seat (6) through threads and screw it until there is no gap between the workpiece and the irregular part fixing seat (6); Step3. Open the double external thread ball valves (2) at both ends of the triple-connection fixing block (3) to facilitate the extraction of gas outside the device to form a pressure difference; Step4. Start the vacuum pump. When the value displayed on the precision pressure gauge (1) reaches the required range, close the double external thread ball valve (2) at the end connected to the vacuum pump and stop extracting the gas inside the device; Step5. Observe the change of the value on the precision pressure gauge (1). If there is no change within 3s, it means that the air tightness of the workpiece meets the requirements, and the air tightness test of one workpiece is completed.

9. The airtightness detection method using the low-pressure airtightness detection device for special-shaped parts according to claim 8, characterized in that: The step1 includes the following steps: Stpe11. First, check whether the air compressor hose (5) is damaged and whether there is air leakage to ensure that there is no air leakage during the test; Stpe12. Check whether the double external thread ball valve (2) is tightened with the triple-connection fixing block (3), the internal thread pneumatic quick connector (7) and the double external thread ball valve (2), and the triple-connection fixing block (3) and the precision pressure gauge (1) to ensure the air tightness of the device; Stpe13. Check whether the precision pressure gauge (1) can work normally, determine whether the range selection is suitable for the workpiece to be tested, and zero the precision pressure gauge (1).

Images