Air tightness test fixture

Abstract

The utility model relates to a kind of airtightness test tool, including base, workpiece seat is equipped on base, sealing structure, airtightness assembly, sealing structure includes sealing cylinder, the sealing ring driven by the piston rod of sealed cylinder, sealing ring telescopic and touches on workpiece through-hole, airtightness assembly includes airtight clamp, the pressing end of airtight clamp is connected with airtight test channel, airtight test channel presses and touches on workpiece through-hole, forms the air inlet path that outside air source and workpiece cavity intercommunication.The utility model is aimed at multiple through-hole parts, provide a kind of tool that can realize positioning, sealing other through hole simultaneously, ensure that the relative position of workpiece itself is stable under force sealing state, facilitate subsequent airtightness test.

Description

Technical Field

[0001] This utility model relates to the field of airtightness testing equipment technology, and in particular to an airtightness testing fixture. Background Technology

[0002] Air tightness testing is an important method for detecting whether an object or system is leaking air, and it is widely used in fields such as automobile manufacturing, aerospace, electronic equipment, and medical devices.

[0003] The pressure decay method, also known as the positive pressure test, works by filling the test piece with gas at a certain pressure and then monitoring the pressure inside the cavity to determine the leakage situation.

[0004] The vacuum decay method, also known as the negative pressure test, works by drawing the inside of the test component into a vacuum state and then monitoring the decay of the vacuum to determine if there is a leak.

[0005] Both methods require complete sealing of other holes in the workpiece. Therefore, keeping all holes except for the vent hole sealed is currently one of the challenges in the industry. Utility Model Content

[0006] In response to the shortcomings of the existing production technology, the applicant provides a reasonably structured airtightness testing fixture that uses the positioning structure as a sealing structure to simultaneously position and seal the workpiece, so as to test the internal pressure.

[0007] The technical solution adopted in this utility model is as follows:

[0008] An airtightness testing fixture includes a base, on which a workpiece holder, a sealing structure, and an airtight component are mounted.

[0009] The sealing structure includes a sealing cylinder and a sealing ring driven by the piston rod of the sealing cylinder. The sealing ring extends and retracts to contact the through hole of the workpiece.

[0010] The airtight component includes an airtight clamp, the pressing end of which is connected to an airtight test channel. The airtight test channel is pressed against the through hole of the workpiece, forming an air intake path that connects the external air source with the inside of the workpiece cavity.

[0011] As a further improvement to the above technical solution:

[0012] The workpiece seat has a sealing surface on the side facing the workpiece.

[0013] The sealing cylinder piston rod of the sealing structure is connected to a push block positioning plate. A sealing push block is provided on the side of the push block positioning plate facing the workpiece, and a sealing ring is located on the side of the sealing push block facing the workpiece.

[0014] The area of ​​the sealing pusher is larger than the area of ​​the sealing ring.

[0015] Each sealed cylinder is equipped with at least two piston rods, which are connected to the opposite corners of the push block positioning plate.

[0016] The sealing structure is symmetrically arranged on both sides of the workpiece, applying a limiting and tightening force to the workpiece.

[0017] The force application points of the sealing structures on both sides are located in the same horizontal plane.

[0018] The airtight clamps drive the airtightness test channel in a vertical reciprocating motion.

[0019] The pressing end of the airtight clamp is connected to an airtight pressure block, the opening of the airtight test channel is connected to the airtight pressure block, and the airtight test channel is pressed and sealed to one of the through holes of the workpiece.

[0020] During the test, the workpiece is completely limited by the workpiece seat, sealing structure, and airtight components.

[0021] The beneficial effects of this utility model are as follows:

[0022] This utility model provides a tooling for multi-hole parts that can simultaneously position and seal other through holes. A sealing ring is added to the piston rod of the sealing cylinder. While the sealing ring is pressed against the through hole to be sealed, the pressing force also serves as a limiting force. Moreover, the pressing force is symmetrically set on both sides of the workpiece to ensure that the relative position of the workpiece is stable under the pressure sealing state, which facilitates subsequent airtightness testing. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the overall structure of this application.

[0024] Figure 2 This is a structural diagram from another perspective of this application.

[0025] Figure 3 This is a perspective view of this application from a low angle.

[0026] Figure 4 This is a schematic diagram of the single-sided sealing structure of this application.

[0027] The components include: 1. base; 2. workpiece holder; 3. clamp holder; 4. airtight clamp; 5. airtight pressure block;

[0028] 501. Air tightness test channel;

[0029] 601. Sealing cylinder; 602. Sealing push block; 603. Sealing ring; 604. Cylinder seat; 605. Piston rod; 606. Push block positioning plate. Detailed Implementation

[0030] The specific embodiments of this utility model are described below with reference to the accompanying drawings.

[0031] like Figures 1-4 As shown, the airtightness testing fixture of this embodiment includes a base 1, on which a workpiece seat 2, a sealing structure, and an airtight component are provided.

[0032] The sealing structure includes a sealing cylinder 601 and a sealing ring 603 driven by the piston rod 605 of the sealing cylinder 601. The sealing ring 603 extends and retracts to abut against the through hole of the workpiece.

[0033] The airtight component includes an airtight clamp 4, the pressing end of which is connected to an airtight test channel 501. The airtight test channel 501 presses against the through hole of the workpiece, forming an air intake path that connects the external air source with the inside of the workpiece cavity.

[0034] The workpiece holder 2 has a sealing surface on the side facing the workpiece.

[0035] The piston rod 605 of the sealing cylinder 601 with the sealing structure is connected to a push block positioning plate 606. The push block positioning plate 606 has a sealing push block 602 on the side facing the workpiece, and the sealing ring 603 is located on the side of the sealing push block 602 facing the workpiece.

[0036] The area of ​​the sealing pusher 602 is larger than the area of ​​the sealing ring 603.

[0037] Each sealed cylinder 601 is equipped with at least two piston rods 605, which are connected to the opposite corners of the push block positioning plate 606.

[0038] The sealing structure is symmetrically arranged on both sides of the workpiece, applying a limiting and tightening force to the workpiece.

[0039] The force application points of the sealing structures on both sides are located in the same horizontal plane.

[0040] The airtight clamp 4 drives the airtight test channel 501 to move vertically back and forth.

[0041] The pressing end of the airtight clamp 4 is connected to an airtight pressure block 5, the opening of the airtight test channel 501 is connected to the airtight pressure block 5, and the airtight test channel 501 is pressed and sealed with one of the through holes of the workpiece.

[0042] During the test, the workpiece is completely limited by the workpiece seat 2, the sealing structure, and the airtight components.

[0043] The specific structure and working principle of this application are as follows:

[0044] like Figure 1The diagram shows the overall structure of this application, including a base 1 and a workpiece holder 2 on the base 1. The workpiece holder 2 is used to hold the workpiece to be tested. As shown in the diagram, the workpiece has multiple interconnected through holes. Therefore, recessed grooves or protruding bumps extending into the bottom through holes of the workpiece can be provided on the workpiece holder 2 to limit the workpiece's position. Since the workpiece needs to be clamped later, it is not necessary to completely limit it; initial limiting is sufficient. After the subsequent clamping action is completed, complete limiting is achieved.

[0045] To ensure that there are no other leaks besides the airflow path during the airtightness test, the surface of the workpiece holder 2 is also provided with a sealing surface such as an adhesive layer.

[0046] The base 1 also features a two-sided sealing structure. This two-sided sealing structure is designed based on the characteristic that the workpiece has through holes on both sides. For example... Figure 1 In the central position, the sealing structures on both the left and right sides are the same. We will take the sealing structure on one side as an example for explanation.

[0047] Reference Figure 4 A cylinder seat 604 is provided on the base 1, and a sealing cylinder 601 is mounted on the side of the cylinder seat 604 facing the workpiece. The piston rod 605 of the sealing cylinder 601 extends towards the workpiece. At least two piston rods 605 are provided to improve the structural stability under pressure. In this embodiment, one piston rod 605 is provided at each diagonal end face of one sealing cylinder 601, so that the cylinder can extend two piston rods 605 at the same time; the ends of the two piston rods 605 are connected to a push block positioning plate 606, and a sealing push block 602 is provided on the side of the push block positioning plate 606 facing the workpiece, and a sealing ring 603 is provided on the side of the sealing push block 602 facing the workpiece. The size of the sealing ring 603 is slightly larger than the through hole to be sealed on the workpiece, so as to completely seal the through hole to be sealed. The push block positioning plate 606 and the sealing push block 602 can be set as round or square, but the dimensions of the push block positioning plate 606 and the sealing push block 602 are required to be similar, or the push block positioning plate 606 is slightly larger than the sealing push block 602, in order to provide a more stable force application structure.

[0048] like Figure 2 As shown, a clamp seat 3 is provided on the side of the workpiece seat 2, and an airtight clamp 4 is provided on the top of the clamp seat 3. An airtight pressure block 5 is connected to the pressing end of the airtight clamp 4. An airtight test channel 501 and a sealing surface are provided on the side of the airtight pressure block 5 facing the workpiece. The airtight test channel 501 is connected to an external air source. While pressing to close a certain through hole, a path for the input airflow is reserved. The sealing surface is used to block other through holes, so that there is only one airflow path for the entire workpiece.

[0049] Since corresponding sealing structures are provided on both sides, when the piston rod 605 of the sealing cylinders 601 on both sides is pushed out and the lateral through hole on the workpiece is blocked by the sealing ring 603, the sealing of both sides of the workpiece is completed. After the top is pressurized, the entire workpiece is pressed onto the workpiece seat 2, and the through hole at the bottom of the workpiece is also sealed. At this time, only the through hole at the top of the workpiece is left as the airflow inlet path. The airflow enters the workpiece, and the pressure sensor senses the pressure change in the workpiece cavity to determine whether the airtightness condition is met. If the pressure increase is at the expected rate or decreases, it proves that the airtightness is qualified; if the rate of pressure change is abnormal, it proves that the airtightness is unqualified.

[0050] As an optional implementation, if the workpiece does not have a through hole at the bottom, for example, it is just a tee, the two side through holes have been blocked, and the top through hole serves as the airflow path, then the workpiece seat 2 may not use a sealing surface structure.

[0051] The advantage of this application is that it can provide a corresponding sealing structure according to the shape of the workpiece, with no other leakage holes besides the airflow inflow path; by inputting airflow into the workpiece cavity and sensing the pressure, it can be determined whether the workpiece is airtight. This application is applicable to both positive and negative pressure tests, and is widely used and reliable.

[0052] The above description is an explanation of the present utility model and not a limitation thereof. The scope of the present utility model is defined by the claims. Within the protection scope of the present utility model, any form of modification may be made.

Claims

1. An airtightness testing fixture, characterized in that: Includes a base (1), on which a workpiece seat (2), a sealing structure, and an airtight component are mounted. The sealing structure includes a sealing cylinder (601) and a sealing ring (603) driven by the piston rod (605) of the sealing cylinder (601). The sealing ring (603) extends and retracts to abut against the through hole of the workpiece. The airtight component includes an airtight clamp (4), and the pressing end of the airtight clamp (4) is connected to an airtight test channel (501). The airtight test channel (501) presses against the through hole of the workpiece to form an air intake path that connects the external air source with the inside of the workpiece cavity.

2. The airtightness testing fixture as described in claim 1, characterized in that: The workpiece seat (2) has a sealing surface on the side facing the workpiece.

3. The airtightness testing fixture as described in claim 1, characterized in that: The piston rod (605) of the sealing cylinder (601) of the sealing structure is connected to a push block positioning plate (606). A sealing push block (602) is provided on the side of the push block positioning plate (606) facing the workpiece, and a sealing ring (603) is located on the side of the sealing push block (602) facing the workpiece.

4. The airtightness testing fixture as described in claim 3, characterized in that: The area of ​​the sealing pusher (602) is larger than the area of ​​the sealing ring (603).

5. The airtightness testing fixture as described in claim 3, characterized in that: Each sealed cylinder (601) is provided with at least two piston rods (605), which are connected to the opposite corners of the push block positioning plate (606).

6. The airtightness testing fixture as described in claim 1, characterized in that: The sealing structure is symmetrically arranged on both sides of the workpiece, applying a limiting and tightening force to the workpiece.

7. The airtightness testing fixture as described in claim 6, characterized in that: The force application points of the sealing structures on both sides are located in the same horizontal plane.

8. The airtightness testing fixture as described in claim 1, characterized in that: The airtight clamp (4) drives the airtight test channel (501) to move vertically back and forth.

9. The airtightness testing fixture as described in claim 8, characterized in that: The pressing end of the airtight clamp (4) is connected to an airtight pressure block (5), the opening of the airtight test channel (501) is connected to the airtight pressure block (5), and the airtight test channel (501) is pressed and sealed with one of the through holes of the workpiece.

10. The airtightness testing fixture as described in any one of claims 1-9, characterized in that: During the test, the workpiece is completely limited by the workpiece seat (2), the sealing structure, and the airtight components.

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