A pressure action air tightness testing device

Abstract

The application discloses a pressure action air tightness test device. It belongs to the field of mechanical manufacturing and testing technology. The device comprises a support frame body for accommodating and supporting a product to be tested; a sealing cavity arranged above the support frame body, the lower end surface of the sealing cavity being provided with a sealing surface for forming a seal with the surface of the product to be tested, the sealing cavity being provided with an air tight joint for connecting an air source; and a linear driving mechanism installed on the support frame body, the driving end of the linear driving mechanism being connected with the sealing cavity, the linear driving mechanism being used for driving the sealing cavity to make vertical lifting movement relative to the support frame body, so that the sealing surface is pressed against or separated from the product to be tested. The application adopts air pressure to simulate water pressure, solves the problems of complicated operation, easy corrosion of products and slow pressure rising of the existing water pressure test method, and has the advantages of simple structure, convenient operation, no corrosion, rapid pressure rising and high test efficiency.

Description

Technical Field

[0001] This invention relates to the field of mechanical manufacturing and testing technology, and more specifically, to a pressure action airtightness testing device. Background Technology

[0002] In certain mechanical or electromechanical devices, there are often mechanisms designed to be triggered by pressure (such as water pressure). For example, the timing mechanism of a certain product contains a water pressure rod assembly, which consists of a water pressure rod, a water pressure diaphragm, and a water pressure spring. The performance requirement for this product is that under specific conditions (such as removing the safety fork), when an external water pressure of 0.05±0.02MPa is applied, its internal timing circuit board should output current to indicate that the pressure-triggered mechanism operates reliably.

[0003] Currently, testing of such products typically employs a hydrostatic pressure vessel. During testing, the entire product is immersed in water within the vessel and then pressurized. This method has several significant drawbacks: First, testing equipment (such as cables) needs to be extracted from the pressure vessel, resulting in complex sealing and extraction structures and significant implementation difficulties. Second, the large volume of the pressure vessel and the slow pressurization process lead to low testing efficiency, especially for large-scale product sampling or full inspection. Third, moisture adheres to the product surface after testing, requiring compressed air drying, increasing the operational steps. Fourth, the product casing is often made of galvanized steel, which is susceptible to corrosion and rust from prolonged or frequent contact with water, affecting the product's appearance and quality. The entire process is cumbersome, time-consuming, labor-intensive, and carries a potential risk of product damage.

[0004] Therefore, there is an urgent need for a pressure action testing device that is simple in structure, easy to operate, highly efficient in testing, and does not damage the product. Summary of the Invention

[0005] This invention provides a pressure-operated airtightness testing device to solve the problems of cumbersome operation, easy corrosion of products, and low testing efficiency in the prior art.

[0006] To achieve the above objectives, the present invention provides a pressure-operated airtightness testing device, comprising: a support frame for accommodating and supporting the product to be tested; a sealing cavity disposed above the support frame, the lower end face of which is provided with a sealing surface for forming a seal with the surface of the product to be tested, and the sealing cavity is provided with an airtight connector for connecting an air source; and a linear drive mechanism mounted on the support frame, the drive end of which is connected to the sealing cavity for driving the sealing cavity to perform vertical lifting and lowering movements relative to the support frame, so that the sealing surface presses against or detaches from the product to be tested.

[0007] Optionally, the linear drive mechanism includes: a handwheel; a lead screw, which is fixedly connected to the handwheel and threadedly engaged with the support frame; the sealing cavity is movably connected to the end of the lead screw via a connector, and when the handwheel is rotated, the lead screw drives the sealing cavity to rise and fall.

[0008] Optionally, the connector is a guide connecting plate, which is fixedly connected to the end of the sealing cavity. The sealing cavity is connected to the lead screw through a limiting pin. When the lead screw moves, the guide connecting plate moves synchronously with the sealing cavity in the lifting direction.

[0009] Optionally, a guide column is fixedly provided on the support frame, and the guide connecting plate is slidably engaged with the guide column to guide the vertical movement path of the sealed cavity.

[0010] Optionally, it also includes: a fixing plate; the fixing plate is disposed on the support frame and is used for threaded connection with the middle part of the lead screw, and fixedly connected to the guide column on both sides.

[0011] Optionally, the support frame includes a left support plate, a right support plate, a left frame for connecting the left support plate, and a right frame for connecting the right support plate, wherein the left and right support plates are provided with limiting stops.

[0012] Optionally, it also includes: at least two oppositely arranged movable clamps, which are movably placed on the limiting stop of the support frame for clamping and supporting the product to be tested, and the movable clamps are made of non-metallic material.

[0013] Optionally, the sealing cavity includes a sealing cover and a sealing gasket, with the sealing gasket disposed on the lower end face of the sealing cover to form the sealing surface.

[0014] Optionally, the sealed cavity is also provided with a needle valve for depressurizing the sealed cavity after the test is completed.

[0015] Optionally, the airtight connector has a tower-shaped structure, with one end sealed to the sealed cavity and the other end used to connect to a high-pressure gas pipe.

[0016] The beneficial effects of this invention are: This invention provides a pressure-operated airtightness testing device. This device uses clean compressed air instead of water as the pressure medium, completely avoiding the problems of drying the product casing after water pressure testing and the risk of rust and corrosion, thus protecting the product surface quality. A linear drive mechanism drives the sealed cavity to press against the product under test, replacing the complex operation of a pressure vessel. The process of product clamping, pressurization, depressurization, and removal is smooth and can be completed quickly by a single person, greatly simplifying the operation process. The small-volume sealed cavity is directly filled with air, eliminating the need to wait for the pressure vessel to build up. The pressure can be instantly established and precisely adjusted to the testing requirement of 0.05±0.02MPa, significantly improving testing efficiency, especially suitable for batch product testing. The device has a simple structure, with most components being machined parts, resulting in low manufacturing costs. By changing different movable clamps and sealed cavities (or sealing gaskets), it can adapt to products with different shapes and testing positions, exhibiting good versatility and expandability. Attached Figure Description

[0017] Figure 1 This is a perspective view of a pressure-operated airtightness testing device provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the support frame provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of the structure of the sealed cavity provided in an embodiment of the present invention; Figure 4 This is a schematic diagram of the timing mechanism provided in an embodiment of the present invention.

[0018] Symbol explanation: Support frame -1, Sealed cavity -2, Left support plate -3, Right support plate -4, Left frame -5, Right frame -6, Connecting bolt -7, Limit stop -8, Sealing cover -9, Airtight joint -10, Sealing gasket -11, Needle valve -12, Handwheel -13, Screw -14, Guide connecting plate -15, Guide column -16, Fixing plate -17, Fixing nut -18, Baffle -19, Timing mechanism -20, Movable clamping plate -21, Limit pin -22. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0020] This embodiment provides a pressure action airtightness test device for testing a certain type of timing mechanism 20. Figure 4This is a schematic diagram of the timing mechanism 20 provided in an embodiment of the present invention; as shown Figure 4 As shown, the timing mechanism 20 (the product under test) has a hydraulic rod assembly. Its operation requirement is: when a pressure of 0.05±0.02MPa is applied to a specific circular area on it, the hydraulic diaphragm deforms, pushes the hydraulic rod to trigger the micro switch, thereby turning on the internal circuit board and outputting current.

[0021] Figure 1 This is a perspective view of a pressure-operated airtightness testing device provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the structure of the support frame 1 provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of the structure of the sealed cavity 2 provided in an embodiment of the present invention; as shown Figures 1 to 3 As shown, the pressure-operated airtightness testing device of this embodiment mainly includes: 1. Support frame 1, used to accommodate and support the product to be tested; In one optional embodiment, the support frame 1 includes a left support plate 3, a right support plate 4, a left frame 5 for connecting the left support plate 3, and a right frame 6 for connecting the right support plate 4. The left support plate 3 and the right support plate 4 are provided with limiting stops 8.

[0022] It also includes: at least two oppositely arranged movable clamps 21, which are movably placed on the limiting stop 8 of the support frame 1 for clamping and supporting the product to be tested, and the movable clamps 21 are made of non-metallic materials.

[0023] Specifically, the support frame 1 is the base of the entire device, and is a split frame structure, consisting of a left frame 5, a right frame 6, a left support plate 3, a right support plate 4, and connecting bolts 7. Specifically, the left support plate 3 is welded to the left frame 5 as a whole, and the right support plate 4 is welded to the right frame 6 as a whole. Then, the left and right parts are fastened together by multiple connecting bolts 7 and matching nuts, forming a stable rigid frame (see...). Figure 2 (See Figure 1 for the support frame). This modular design facilitates processing and assembly.

[0024] On the upper surfaces of the left support plate 3 and the right support plate 4, inwardly recessed limiting stops 8 are machined. These stops are used to place and position the movable clamping plate 21. In this embodiment, the movable clamping plate 21 is designed as two crescent-shaped plates that can be placed relatively movable on the limiting stops 8 of the left and right support plates. When testing is required, the operator places the timing mechanism 20 between the two movable clamping plates 21 and then pushes the two movable clamping plates 21 together, thereby clamping the lower housing of the timing mechanism 20 and providing a stable and precise support plane for the product. The movable clamping plate 21 is made of phenolic glass cloth, a non-metallic material with good insulation properties and mechanical strength. Its smooth surface effectively protects the galvanized layer of the product housing during clamping, preventing scratches.

[0025] 2. A sealed cavity 2 is disposed above the support frame 1, and its lower end face is provided with a sealing surface for forming a seal with the surface of the product to be tested. The sealed cavity 2 is provided with an airtight connector 10 for connecting an air source. In an optional embodiment, the sealing cavity 2 includes a sealing cover 9 and a sealing gasket 11, wherein the sealing gasket 11 is disposed on the lower end face of the sealing cover 9, forming the sealing surface.

[0026] The sealed cavity 2 is also equipped with a needle valve 12, which is used to depressurize the sealed cavity 2 after the test is completed.

[0027] The airtight connector 10 has a tower-shaped structure, with one end sealed to the sealed cavity 2 and the other end used to connect to a high-pressure air pipe.

[0028] Specifically, the specific structure of the sealed cavity 2 is as follows: Figure 3 (Structural diagram of sealing cavity 2) shows that it mainly consists of a sealing cover 9, a sealing gasket 11, an airtight connector 10, and a needle valve 12. The sealing cover 9 is a metal cavity with a groove machined on its lower end face for installing the sealing gasket 11. The sealing gasket 11 is made of highly elastic rubber material and protrudes or lies flush with the lower end face of the sealing cover 9, forming a sealing surface that contacts the product under test. An airtight connector 10 is welded to the top of the sealing cover 9. This connector has a tower-shaped structure; one threaded end screws into the sealing cover 9 and achieves airtightness through the rubber sealing gasket, while the other end of its tower-shaped (barbed) structure is used to tightly connect to a high-pressure air hose. Simultaneously, a needle valve 12 is welded to the side wall of the sealing cover 9. The valve needle is connected to the valve body via threads. By screwing the valve needle in or out, the opening of the valve port can be precisely controlled, enabling rapid release or fine adjustment of the internal air pressure of the sealing cavity 2.

[0029] 3. A linear drive mechanism is installed on the support frame 1, and its drive end is connected to the sealing cavity 2. It is used to drive the sealing cavity 2 to move vertically up and down relative to the support frame 1 so that the sealing surface presses against or detaches from the product to be tested.

[0030] In an optional implementation, the linear drive mechanism includes: Handwheel 13; The lead screw 14 is fixedly connected to the handwheel 13 and threadedly engaged with the support frame 1; The sealed cavity 2 is movably connected to the end of the lead screw 14 via a connector. When the handwheel 13 is rotated, the lead screw 14 drives the sealed cavity 2 to rise and fall.

[0031] In an optional embodiment, the connector is a guide connecting plate 15, which is fixedly connected to the end of the sealing cavity 2. The sealing cavity 2 is connected to the lead screw 14 through a limiting pin 22. When the lead screw 14 moves, the guide connecting plate 15 moves synchronously with the sealing cavity 2 in the lifting direction.

[0032] In one optional embodiment, a guide post 16 is fixedly provided on the support frame 1, and the guide connecting plate 15 is slidably engaged with the guide post 16 to guide the vertical movement path of the sealed cavity 2.

[0033] In an optional embodiment, the device further includes: a fixing plate 17; The fixing plate 17 is disposed on the support frame 1 and is used to be threadedly connected to the middle part of the lead screw 14, and is fixedly connected to the guide column 16 on both sides.

[0034] Specifically, the linear drive mechanism is manual and includes a handwheel 13, a lead screw 14, a guide connecting plate 15, a guide column 16, and a fixing plate 17.

[0035] Two guide columns 16 are provided, one of which is fixedly connected to the left support plate 3 by a nut, and the other is fixedly connected to the right support plate 4 by a nut; the two guide columns 16 are arranged in parallel. A fixing plate 17 is provided above the support frame 1, passes through the guide columns 16 and is fixedly connected to the guide columns 16 by a nut.

[0036] The guide connecting plate 15 is a key motion conversion and connection component. It has a through hole machined in the middle, which mates with the end of the sealing cavity 2, that is, the end of the sealing cavity 2 passes through the through hole. The two ends of the guide connecting plate 15 have semi-circular grooves that match the diameter of the guide posts 16, so that it can be fitted onto the two guide posts 16 and can slide smoothly up and down along the guide posts 16.

[0037] The upper end of the lead screw 14 passes through the center hole of the fixing plate 17 and is fixedly connected to the handwheel 13. A baffle 19 and a fixing nut 18 are also provided between the handwheel 13 and the lead screw 14 to secure the handwheel 13 to the lead screw 14 and prevent loosening. The lower end of the lead screw 14 is screwed into the threaded hole at the end of the sealing cavity 2.

[0038] The connection between the sealing cavity 2 and the lead screw 14 is ingenious. A pin hole is provided on the top side of the sealing cavity 2, and a limiting pin 22 is inserted to connect the sealing cavity 2 to the lead screw 14. This connection method allows the sealing cavity 2 to move synchronously with the lead screw 14. When the lead screw 14 moves, the sealing cavity 2 follows the lead screw 14. Because the end of the sealing cavity 2 is fixedly connected to the guide connecting plate 15, the guide connecting plate 15 also moves synchronously with the sealing cavity 2.

[0039] The working process of this device will be explained in detail below with a complete test procedure.

[0040] Step 1: Preparation before testing The operator first removes the timing mechanism 20 to be tested from the storage area. The product's appearance is visually inspected to confirm there is no damage. Then, the handwheel 13 on the device is rotated counterclockwise, causing the lead screw 14 to lift the guide connecting plate 15 and the sealing cavity 2 to their highest position, providing sufficient space for placing the product. Next, the two crescent-shaped movable clamps 21 are placed on the limiting stops 8 of the left support plate 3 and the right support plate 4 of the support frame 1.

[0041] Step 2: Product clamping and positioning The operator carefully places the timing mechanism 20 between the two movable clamping plates 21 and adjusts its position so that the circular area to be pressurized (i.e., the location of the water pressure rod assembly) is directly below the sealed cavity 2. Then, the two movable clamping plates 21 are pushed towards the center to clamp the housing of the timing mechanism 20. Because the movable clamping plates 21 are made of phenolic fiberglass cloth, the clamping process will not scratch the surface of the timing mechanism 20. At this point, the timing mechanism 20 is stably and accurately positioned on the support frame 1.

[0042] Step 3: Connect the test circuit Because the support frame 1 adopts an open design, ample space is left below and around the product. Operators can easily insert one end of the dedicated test cable into the test socket on the side of the timing mechanism 20, and the other end of the cable is connected to a dedicated circuit testing device for monitoring the product's operating current.

[0043] Step 4: Tighten and seal After completing the circuit connection, the operator removes the limiting pin 22 that limits the sealing cavity 2 and begins to rotate the handwheel 13 clockwise. The rotation of the handwheel 13 drives the lead screw 14 to rotate. Since the lead screw 14 and the end of the sealing cavity 2 (whose rotation is limited by the guide post 16) form a lead screw 14 nut pair, the rotational motion of the lead screw 14 is converted into the vertical downward movement of the sealing cavity 2. The guide connecting plate 15 follows the sealing cavity 2 and moves smoothly downward along the guide post 16.

[0044] As handwheel 13 continues to rotate, the rubber sealing gasket 11 on the lower end face of the sealing cavity 2 gradually approaches and eventually contacts the upper housing of the timing mechanism 20. When the sealing gasket 11 contacts the surface of the timing mechanism 20 and a slight resistance is felt, the operator can feel a slight increase in the torque of handwheel 13. At this time, by rotating handwheel 13 by about 1 / 4 to 1 / 2 turn with a little more force, the sealing gasket 11 undergoes a certain compression deformation, thereby forming a reliable sealed space between the sealing cavity 2 and the product housing. This space exactly covers the area of ​​the product's hydraulic rod assembly.

[0045] Step 5: Apply air pressure and monitor performance After compression, the operator places the high-pressure hose (i.e., high-pressure air pipe) connected to the air source onto the airtight connector 10 of the sealed cavity 2 (the tower-shaped structure of the airtight connector 10 ensures a secure connection). The operator slowly opens the pressure reducing valve on the air source to fill the sealed cavity 2 with compressed air. Simultaneously, the operator closely observes the precision pressure gauge connected to the air circuit. When the pressure gauge pointer stably points to 0.05 MPa (i.e., the midpoint of the required pressure range of 0.05 ± 0.02 MPa), the pressurization is stopped.

[0046] At this time, the air pressure inside the sealed cavity 2 acts on the water pressure diaphragm of the timing mechanism 20, simulating a water pressure of 0.05 MPa. The water pressure diaphragm deforms under the air pressure, pushing the water pressure rod downwards. The water pressure rod overcomes the elastic force of the water pressure spring and moves downwards. When the pressure reaches the set value, the bottom end of the water pressure rod just touches the contact of the microswitch located below it. The microswitch closes, thus connecting the power circuit of the circuit board inside the timing mechanism 20. At this instant, the operator can clearly see the current value displayed on the circuit testing device connected to the product jump from 0 to a stable value (e.g., tens of milliamps), indicating that the product is operating normally and its performance is qualified. If no current appears when the pressure is between 0.03 MPa and 0.07 MPa, it is judged as unqualified.

[0047] Step 6: Depressurize and remove the product After the test is completed, the operator first shuts off the air supply. Then, the operator slowly loosens the valve needle of the needle valve 12 on the sealed cavity 2. A hissing sound of air release can be heard, and the air pressure inside the sealed cavity 2 drops rapidly, causing the pressure gauge pointer to return to zero. After depressurization, the operator rotates the handwheel 13 counterclockwise, driving the lead screw 14 upward, which in turn raises the guide connecting plate 15 and the sealed cavity 2, causing the sealing gasket 11 to detach from the surface of the timing mechanism 20.

[0048] Step 7: Disassemble the product and begin a new round of testing. The operator disconnects the test cable, removes the two movable clamps 21, and takes out the timing mechanism 20 after testing. At this point, the entire testing cycle (clamping, wiring, pressurizing, monitoring, depressurizing, and removal) is completed in less than one minute. Compared to the traditional autoclave's pressurization and subsequent drying process, which often takes several minutes, the efficiency is significantly improved. The operator can immediately place the next product (i.e., the timing mechanism 20) and begin a new round of testing.

[0049] As can be seen from the detailed examples above, the pressure-operated airtightness testing device of the present invention, through its ingenious structural design, simplifies the complex pressure testing process into a few simple steps: "loading the product - turning the handwheel 13 - inflating and checking the gauge - deflating - removing the product." It successfully replaces the test medium from water to gas, fundamentally solving the product corrosion problem; through the handwheel 13, lead screw 14, and guide column 16, it achieves rapid, accurate, and reliable sealing of the product testing area; and the reserved space facilitates the connection of the test circuit. The entire device is simple in structure, low in cost, easy to operate, and highly efficient in testing, possessing extremely high practical value.

[0050] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A pressure-operated airtightness testing device, characterized in that, include: Support frame, used to hold and support the product to be tested; A sealed cavity is disposed above the support frame, and its lower end face is provided with a sealing surface for forming a seal with the surface of the product to be tested. The sealed cavity is provided with an airtight connector for connecting an air source. A linear drive mechanism is installed on the support frame, and its drive end is connected to the sealing cavity. It is used to drive the sealing cavity to move vertically up and down relative to the support frame so that the sealing surface presses against or detaches from the product under test.

2. The pressure-operated airtightness testing device according to claim 1, characterized in that, The linear drive mechanism includes: Handwheel; The lead screw is fixedly connected to the handwheel and threadedly engaged with the support frame body; The sealed cavity is movably connected to the end of the lead screw via a connector. When the handwheel is rotated, the lead screw drives the sealed cavity to rise and fall.

3. The pressure-operated airtightness testing device according to claim 2, characterized in that: The connector is a guide connecting plate, which is fixedly connected to the end of the sealing cavity. The sealing cavity is connected to the lead screw through a limiting pin. When the lead screw moves, the guide connecting plate moves synchronously with the sealing cavity in the lifting direction.

4. The pressure-operated airtightness testing device according to claim 3, characterized in that: A guide column is fixedly installed on the support frame, and the guide connecting plate slides with the guide column to guide the vertical movement path of the sealed cavity.

5. The pressure-operated airtightness testing device according to claim 4, characterized in that, Also includes: Fixing plate; The fixing plate is mounted on the support frame and is used for threaded connection with the middle part of the lead screw, and is fixedly connected to the guide column on both sides.

6. The pressure-operated airtightness testing device according to claim 1, characterized in that: The support frame includes a left support plate, a right support plate, a left frame for connecting the left support plate, and a right frame for connecting the right support plate. The left and right support plates are provided with limiting stops.

7. The pressure-operated airtightness testing device according to claim 6, characterized in that... It also includes: At least two opposing movable clamps are provided, which are movably placed on the limiting stop of the support frame to clamp and support the product to be tested. The movable clamps are made of non-metallic material.

8. The pressure-operated airtightness testing device according to claim 1, characterized in that: The sealed cavity includes a sealing cover and a sealing gasket, with the sealing gasket disposed on the lower end face of the sealing cover, forming the sealing surface.

9. The pressure-operated airtightness testing device according to claim 1, characterized in that: The sealed cavity is also equipped with a needle valve for depressurizing the sealed cavity after the test is completed.

10. The pressure-operated airtightness testing device according to claim 1, characterized in that: The airtight connector has a tower-shaped structure, with one end sealed to the sealed cavity and the other end used to connect to a high-pressure air pipe.

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