Air tightness testing equipment

Abstract

The present application relates to an air tightness testing device, including a positive pressure module and a main air circuit connected to the positive pressure module, the other end of the main air circuit is connected to the workpiece to be tested, and a one-way valve is arranged on the main air circuit; a branch air circuit is connected in parallel to the main air circuit, the other end of the branch air circuit is connected to a plug module, and the plug module is pressed on the workpiece to be tested. The plug module is used to block part of the holes of the workpiece, and positive pressure is input to the workpiece through the air holes on the carrier. The air tightness testing device can control the pressure and time required for the workpiece detection, and the workpiece is tested by gas without damaging the product, so as to facilitate the detection of the gas tightness of each workpiece, thereby ensuring the full detection of the air tightness of the product and avoiding the omission of defective products.

Description

Technical Field

[0001] The present application relates to the field of air tightness detection technology engineering, and specifically to an air tightness detection device. Background Art

[0002] Since Wim Fleischmann of Germany first invented the concept of negative pressure closed drainage in 1993 and applied it in clinical practice, negative pressure closed drainage technology (abbreviated as NPWT) has been recognized to improve wound drainage, increase blood perfusion, and promote the growth of granulation tissue. NPWT has been widely used in the treatment of various acute and chronic wounds. The NPWT system has a broad market and application space. One of its important advantages is that it can apply negative pressure to the closed wound more accurately and stably. The main design to achieve this important advantage comes from the fluid collection container, namely the fluid collection tank.

[0003] The fluid accumulating tank in the NPWT system has strict requirements on the gas sealing. When the gas sealing of the fluid accumulating tank is insufficient, the pressure sensor of the NPWT system cannot obtain the accurate pressure at the closed wound, resulting in the NPWT system being unable to apply accurate negative pressure to the closed wound, and unable to play a good therapeutic role on the closed wound. In severe cases, the NPWT system cannot operate normally. Therefore, during the production process of the fluid accumulating tank, the gas sealing of the fluid accumulating tank will be strictly tested to ensure that the gas sealing of the fluid accumulating tank meets the use requirements of the NPWT system.

[0004] The outer shell of the liquid storage tank is mainly made of hard plastic. In order to form a complete tank body, it generally needs to undergo secondary processing. The most commonly used method is ultrasonic compression welding. The current airtightness test methods for liquid storage tanks include: visual ultrasonic line compression degree judgment and immersion in liquid sealing test. The existing testing methods all have major defects. The visual method cannot accurately judge the degree of gas sealing of the liquid storage tank, and the outer shell made of non-transparent materials cannot be visually inspected; immersion in the existing water sealing tester, the conclusion is very accurate, but the product will be scrapped after the test, it can only be used for random inspections, and the gas sealing of each product cannot be ensured. The airtightness test of liquid storage tank products has become an issue that needs to be solved urgently. Summary of the invention

[0005] In order to solve the above technical problems, this application provides the following technical solutions:

[0006] The present application provides an airtightness detection device, comprising:

[0007] A positive pressure module and a main gas path connected to the positive pressure module, the other end of the main gas path is connected to the workpiece to be tested, and a one-way valve is arranged on the main gas path;

[0008] A branch air path is connected in parallel to the main air path, and the other end of the branch air path is connected to a plug module, which is pressed onto a workpiece to be inspected.

[0009] In one embodiment, the main gas circuit is further provided with an air flow regulator, which is located between the one-way valve and the positive pressure module.

[0010] In one embodiment, the main gas circuit is further provided with a solenoid valve, and the solenoid valve is located between the one-way valve and the workpiece to be detected.

[0011] In one embodiment, the main gas circuit is further provided with an air pressure detector, and the air pressure detector is located between the one-way valve and the workpiece to be detected.

[0012] In one embodiment, the solenoid valve is a three-way solenoid valve, two interfaces of the solenoid valve are respectively connected to the one-way valve and the workpiece to be detected, and the other interface is connected to the exhaust port.

[0013] In one embodiment, the one-way valve is a fine-adjustable one-way valve.

[0014] In one embodiment, a reversing valve is provided on the gas path.

[0015] In one embodiment, a carrier is further included, and the workpiece to be inspected is loaded on the carrier.

[0016] In one embodiment, the carrier has an air hole, the workpiece to be inspected is connected to the air hole, and the main air path is connected to the air hole.

[0017] In one embodiment, a loading groove is provided on the carrier, an air passage connected to the main air path is provided inside the carrier, and air holes are formed on the bottom surface of the loading groove.

[0018] This application has at least the following beneficial effects:

[0019] In the present application, the plug module is driven by the positive pressure module to block some holes of the workpiece to be inspected. At the same time, the positive pressure module sends positive pressure gas into the workpiece to be inspected through the main gas circuit. The air pressure of the workpiece to be inspected increases with the increase of gas, and the air tightness of the workpiece to be inspected is then detected. The air tightness detection equipment can control the pressure and time required for the workpiece detection, and the workpiece is detected by gas without damaging the product, so as to facilitate the gas sealing detection of each workpiece, thereby ensuring a full detection of the air tightness of the product and avoiding the omission of defective products.

[0020] The one-way valve set in the main gas line limits the gas reflux. The main reason for the fluctuation of the gas pressure value of the workpiece to be tested is gas reflux or leakage. The one-way valve limits the gas reflux and eliminates the factor of gas pressure fluctuation caused by reflux, thereby ensuring the accuracy of the test results. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A schematic diagram of the structure of an airtightness detection device provided in one embodiment of the present application at a first viewing angle.

[0022] Figure 2 A schematic diagram of the structure of an airtightness detection device provided in one embodiment of the present application at a second viewing angle.

[0023] Figure 3 This is a schematic diagram of the structure of the air circuit in the air tightness detection equipment provided in one embodiment of the present application.

[0024] Figure 4 A simplified schematic diagram of the air circuit in the air tightness detection equipment provided in one embodiment of the present application.

[0025] Figure 5 A schematic diagram of the structure of a carrier provided in one embodiment of the present application.

[0026] Reference numerals:

[0027] 11. Positive pressure module; 12. Carrier; 13. Reversing valve; 14. Air flow regulator; 15. Check valve; 16. Solenoid valve; 17. Air pressure detector; 18. Exhaust port;

[0028] 121, material loading trough; 122, air hole;

[0029] 21. Cylinder; 22. Plug module;

[0030] 3. Workpiece. DETAILED DESCRIPTION

[0031] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0032] In the description of the present application, it should be understood that if the terms "length", "width", "thickness", "up", "down", "vertical", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. appear, the orientation or position relationship indicated by these terms is based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present application and simplifying the description, and does 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 application.

[0033] In addition, if the terms "first", "second", and "third" appear, these terms are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first", "second", and "third" may explicitly or implicitly include at least one of the features. In the description of this application, if the term "plurality" appears, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0034] In this application, unless otherwise clearly specified and limited, if the terms "installed", "connected", "connected", "fixed" and the like appear, these terms should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integrated connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0035] In the present application, unless otherwise clearly specified and limited, if there is a description that a first feature is "above" or "below" a second feature, etc., or similar descriptions appear, it may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "above" and "above" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. The first feature being "below", "below" and "below" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0036] It should be noted that if an element is referred to as being "fixed to" or "disposed on" or "set on" another element, it may be directly on the other element or there may be a central element. If an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. If any, the terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in this application are for illustrative purposes only and do not represent the only implementation method.

[0037] The embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0038] Reference Figure 1-3As shown, in some embodiments of the present application, an air tightness detection device is provided, including: an air blocking component, a positive pressure module 11, and a carrier 12, on which a workpiece 3 is loaded. The air blocking component includes a cylinder 21 and a plug module 22, and the cylinder 21 drives the plug module 22 to move toward the workpiece 3 on the carrier 12, and the plug module 22 plugs the hole on the workpiece 3. The carrier 12 is provided with an air hole 122, specifically, in combination with Figure 5 As shown, a loading groove 121 is provided on the carrier 12, and the workpiece 3 is installed in the loading groove 121, and the air hole 122 is provided on the bottom surface of the loading groove 121. The positive pressure module 11 is connected to the cylinder 21 and the carrier 12 respectively through an air flow channel. The positive pressure module 11 is connected to the air hole 122 to release positive pressure gas from the air hole 122. The air hole 122 corresponds to another part of the hole position on the workpiece 3. After the positive pressure gas enters the interior of the workpiece 3, since a part of the hole position is blocked by the plug module 22, the other part of the hole position has positive pressure gas. Under the premise that the sealing workpiece 3 has good sealing performance, the workpiece 3 will be in a positive pressure state and keep consistent with the air pressure of the air flow channel. At the same time, the positive pressure module 11 also provides a driving force for the cylinder 21 to drive the plug module 22 to move to achieve the purpose of blocking the hole position on the workpiece 3.

[0039] In this solution, a portion of the holes of the workpiece 3 is blocked by the plug module 22, and positive pressure gas is input into the workpiece 3 through the air hole 122 on the carrier 12 to detect the air tightness of the workpiece 3. In fact, the workpiece 3 is clamped by the plug module 22 and the carrier 12, so that the holes of the workpiece 3 fit the plug module 22 and the air hole 122, and the workpiece 3 is connected to the air flow channel.

[0040] The air tightness detection device can control the pressure required for the detection of the workpiece 3 by controlling the passage area of ​​the air flow channel, and control the time required for the detection by controlling the working time of the positive pressure module 11, thereby realizing the controllable pressure and detection time of the workpiece 3. In addition, compared with the method of immersing the workpiece in liquid for sealing test, the workpiece is tested by gas without destroying the product, so that the gas tightness of each workpiece can be tested, thereby ensuring the full detection of the product's air tightness and avoiding the omission of defective products. Compared with the visual observation method, the positive pressure air tightness detection has intuitive data that can accurately screen defective products.

[0041] Furthermore, the air flow channel includes a main air path A1 and a branch air path A2, and the positive pressure module 11 is connected to the carrier 12 via the main air path A1. The branch air path A2 is connected in parallel to the main air path A1, and the cylinder 21 is arranged in the branch air path A2.

[0042] In this scheme, reference Figure 4As shown, the main gas circuit A1 is provided with a positive pressure module 11, an airflow regulator 14, a one-way valve 15, a solenoid valve 16 and a carrier 12 in sequence. Since the one-way valve 15 limits the backflow of the airflow, the one-way valve 6 is arranged on the main gas circuit A1 to eliminate the factor of the fluctuation of the air pressure value of the workpiece to be detected caused by the backflow, thereby ensuring the accuracy of detecting defective products. The one-way valve 15 can actually control the amount of air passing through itself. Therefore, in this solution, the one-way valve 15 is a fine-tunable one-way valve, and the fine-tunable one-way valve is specifically a one-way valve that can adjust the amount of air passing through. In addition, the airflow regulator 14 can also adjust the amount of air passing through. The difference between the airflow regulator 14 and the fine-tunable one-way valve in this case is that the airflow regulator 14 can be adjusted to a large extent, which is specifically manifested in a large metering amount and a large adjustment amount each time, while the fine-tunable one-way valve can be adjusted to a small extent.

[0043] The main air path A1 is divided into a first air section, a second air section and a third air section via the air flow regulator 14 and the one-way valve 15, wherein the first air section is the section from the positive pressure module 11 to the air flow regulator 14, the second air section is the section from the air flow regulator 14 to the one-way valve 15, and the third air section is the section from the one-way valve 15 to the carrier 12. The air pressure values ​​of the first air section, the second air section and the third air section may be completely consistent or partially consistent, or may be different.

[0044] Specifically, the positive pressure module 11 inputs gas into the first air section so that the air pressure of the first air section increases, the air flow regulator 14 can adjust the air pressure of the first air section and the second air section, and the adjustment of the one-way valve 15 controls the air pressure of the third air section. The air path A2 is connected in parallel to the first air section, and the air pressure of the first air section and the air path A2 are kept consistent. The air pressure value of the air path A2 can be controlled by the air flow regulator 14. Adjusting the air pressure of the air path A2 can control the movement of the cylinder 21, thereby controlling the speed at which the cylinder 21 drives the plug module 22 to descend or rise. Compared with the air pressure of the second air section, which is affected by both the air flow regulator 14 and the one-way valve 15, the air pressure is more likely to fluctuate. The air pressure in the first air section is affected by the air flow regulator 14. Under the premise that the relationship between the air flow rate of the air flow regulator 14 and the input gas volume remains unchanged, the air pressure value of the first air section can be maintained in a stable state, which can ensure that the cylinder 21 drives the plug module 22 smoothly.

[0045] In addition, in the above scheme, the air flow rate is adjusted by the air flow regulator 14 and the one-way valve 15. The air flow rate passing through the one-way valve 15 first depends on the air pressure value of the second air segment. The air flow regulator 14 can ensure that the air pressure value of the second air segment is close to the expected air pressure value of the third air segment through adjustment, and then the one-way valve 15 can finely adjust the air pressure value of the third air segment to reach the expected air pressure value.

[0046] In some embodiments of the present application, the solenoid valve 16 is a three-way solenoid valve, and two interfaces of the solenoid valve 16 are respectively connected to the one-way valve 15 and the carrier 12, and the other interface is connected to the exhaust port 18. The solenoid valve 16 is used to control the positive pressure gas to enter the carrier 12. In order to avoid excessive air pressure in the gas path, in this solution, one interface of the solenoid valve 16 is also connected to the exhaust port 18. When the air pressure in the gas path is too high, part of the gas can be discharged to ensure that a safe high pressure state is maintained in the gas path.

[0047] Furthermore, the main gas circuit A1 is also provided with an air pressure detector 17, which is located between the one-way valve 15 and the carrier 12. More specifically, the air pressure detector 17 is provided between the solenoid valve 16 and the carrier 12 to detect the airtightness of the workpiece 3 on the carrier 12. Specifically, the air pressure detector 17 in this solution also has a preset function, and a pressure value can be preset in the air pressure detector 17.

[0048] In some embodiments of the present application, a reversing valve 13 is provided on the branch gas path A2, and the reversing valve 13 is provided at the upstream of the cylinder 21. The reversing valve 13 controls the reciprocating motion of the cylinder 21. Specifically, the two switchable output ends of the reversing valve 13 are connected to the cylinder 21, and the input end of the reversing valve 13 is connected to the main gas path A1, one of the output ends controls the extension of the power output shaft of the cylinder 21, and the other output end controls the retraction of the power output shaft of the cylinder 21, and the reciprocating motion of the cylinder 21 can be realized by switching the two output ends.

[0049] The method for detecting the air tightness of a workpiece based on the air tightness detection device includes the following steps:

[0050] S1, parameter setting and status confirmation of air tightness testing equipment: Turn on the air tightness testing equipment, preset the pressure value on the air pressure detector 17, set the pressure holding time, and confirm whether the positive pressure module 11 and the air holes 122 on the carrier 12 can work normally.

[0051] Specifically, a. Turn on the power knob of the sealing tester. The preset pressure value of the air pressure detector 17 is 300 mmHg. The pressure holding time is adjusted to 30 seconds;

[0052] b. Turn on the positive pressure module 11, and you can hear the air compressor of the positive pressure module 11 start to work;

[0053] c. After plugging the leaking sample hole for status confirmation, load the sample into the carrier 12;

[0054] d. After confirming that the sample is loaded, start the test. After the test is completed within 30 seconds, if leakage is detected in the liquid storage tank, it proves that the air tightness detection equipment is working normally.

[0055] S2, inspecting the workpiece 3 to be inspected, loading the workpiece 3 to be inspected into the carrier 12, and starting the test. The test is specifically that the pressure reaches 300 mmHg and is maintained for 30 seconds.

[0056] S3 . After the inspection is completed, the workpiece 3 is moved out of the carrier 12 .

[0057] In this specific embodiment, a qualified product is characterized by being able to maintain a positive pressure of 300 mmHg in the workpiece 3 within 30 seconds, otherwise it is a defective product.

[0058] The above embodiments are used to further illustrate the present application, but the present application is not limited to these specific implementations. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application should be understood to be within the scope of protection of the present application.

Claims

1. An airtightness detection device, characterized in that: include: A positive pressure module (11) and a main gas path (A1) connected to the positive pressure module (11), the other end of the main gas path (A1) being connected to a workpiece to be inspected (3), and a one-way valve (15) being provided on the main gas path (A1); The main gas path (A1) is connected in parallel with a branch gas path (A2), the other end of the branch gas path (A2) is connected to a plug module, and the plug module is pressed onto the workpiece (3) to be inspected.

2. The airtightness detection device according to claim 1, characterized in that: The main air path (A1) is also provided with an airflow regulator (14), and the airflow regulator (14) is located between the one-way valve (15) and the positive pressure module (11).

3. The airtightness detection device according to claim 2, characterized in that: The main gas circuit (A1) is also provided with a solenoid valve (16), and the solenoid valve (16) is located between the one-way valve (15) and the workpiece (3) to be detected.

4. The airtightness detection device according to any one of claims 1 to 3, characterized in that: The main gas circuit (A1) is also provided with a gas pressure detector (17), and the gas pressure detector (17) is located between the one-way valve (15) and the workpiece (3) to be detected.

5. The airtightness detection device according to claim 3, characterized in that: The solenoid valve (16) is a three-way solenoid valve, two interfaces of the solenoid valve (16) are respectively connected to the one-way valve (15) and the workpiece to be detected (3), and the other interface is connected to the exhaust port (18).

6. The airtightness detection device according to claim 1, characterized in that: The one-way valve (15) is a finely adjustable one-way valve.

7. The airtightness detection device according to claim 1, characterized in that: The gas branch path (A2) is provided with a reversing valve (13).

8. The airtightness detection device according to claim 1, characterized in that: It also includes a carrier (12), on which the workpiece (3) to be inspected is loaded.

9. The airtightness detection device according to claim 8, characterized in that: The carrier (12) has an air hole (122), the workpiece (3) to be inspected is connected to the air hole, and the main air path (A1) is connected to the air hole (122).

10. The airtightness detection device according to claim 9, characterized in that: The carrier (12) is provided with a material loading groove (121), the carrier (12) has an air passage in communication with the main air path (A1), and the air hole (122) is formed on the bottom surface of the material loading groove (121).

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