Driving shaft long rod inner ball cage bushing air tightness detection tool

Abstract

The application relates to a driving shaft long-rod inner ball cage shaft sleeve air tightness detection tool, and relates to the technical field of air tightness detection, which comprises a rack, an air tightness base fixedly connected to the rack, a test groove for accommodating a driving shaft to be detected being formed in the air tightness base, the shaft sleeve of the driving shaft to be detected being closely combined with the air tightness base when the driving shaft to be detected is inserted into the test groove, a pressurizing structure in communication with the test groove in the air tightness base and used for conveying gas into the test groove to pressurize the test groove, a limiting structure installed on the rack and used for fixing the driving shaft to be detected, the driving shaft to be detected being vertically arranged when the limiting structure fixes the driving shaft to be detected, and one end of the driving shaft to be detected with the shaft sleeve being inserted into the test groove of the air tightness base downwards. The application has the effect of improving the detection efficiency.

Description

Technical Field

[0001] This application relates to testing fixtures, and more particularly to a fixture for testing the airtightness of the inner ball cage bushing of a drive shaft long rod. Background Technology

[0002] As a core component of the automotive chassis drive system, the constant velocity joint (CV joint) mainly consists of a bell-shaped housing, a three-column housing, an inner star wheel, a cage, steel balls, a gear ring, and a bushing. The bushing is a component of the CVT, and its main function is to seal the space between the bell-shaped housing shaft and the transmission, preventing oil leakage from the transmission oil tank. Before installation, grease is applied to the inside of the bushing to reduce wear during installation. The airtightness of the bushing directly affects the vehicle's overall oil leak prevention function; therefore, it is necessary to test the airtightness of the CVT bushing. The traditional testing method is the water immersion method, where the workpiece is installed in a sealing mold and submerged in water. Compressed air is then introduced through the sealing mold, and the presence of air bubbles is observed to determine if there are any sealing problems.

[0003] However, after the water immersion test, drying and rust prevention treatments are required; otherwise, the workpiece will rust. These additional drying and rust prevention treatments increase the number of steps and thus increase costs. Utility Model Content

[0004] The purpose of this application is to provide a tooling for testing the airtightness of the inner ball cage bushing of the drive shaft long rod, thereby reducing testing costs.

[0005] The technical solution provided in this application for a tooling for testing the air tightness of the inner ball cage bushing of a long drive shaft is as follows: it includes a frame;

[0006] An airtight seat is fixedly connected to the frame. The airtight seat has a test slot for accommodating the drive shaft to be tested. When the drive shaft to be tested is inserted into the test slot, the bushing of the drive shaft to be tested fits tightly with the airtight seat.

[0007] The pressurization structure is connected to the test tank inside the airtight seat and is used to supply gas into the test tank to pressurize the test tank.

[0008] A limiting structure, mounted on the frame, is used to fix the drive shaft to be tested;

[0009] When the limiting structure fixes the drive shaft under test, the drive shaft under test is set vertically, and the end of the drive shaft under test with the bushing is inserted downward into the test groove of the airtight seat.

[0010] By employing the above technical solution, the grease pre-coated inside the bushing allows pressurized gas to penetrate the grease and form visible oil film bubbles when a leak occurs, thus achieving a "dry" leak detection method. Compared to the traditional water immersion method, this avoids the cumbersome subsequent drying and rust prevention processes, significantly improving detection efficiency and saving production costs. Furthermore, by vertically fixing the drive shaft and inserting its bushing end downwards into the airtight seat, a stable and reliable detection environment is created.

[0011] Optionally, a sealing groove is provided within the test groove, and a lip seal is installed within the sealing groove. The outer wall of the lip seal is tightly fitted with the groove wall of the sealing groove, and the inner wall of the lip seal is used to tightly fit with the outer peripheral wall of the bushing.

[0012] By adopting the above technical solution, a lip seal is used as a dynamic sealing element. The lip seal has excellent following and self-sealing effects.

[0013] Optionally, the test slot includes a first limiting slot and a second limiting slot connected sequentially from bottom to top. The outline of the first limiting slot is adapted to the spline outer ring of the drive shaft under test and is in clearance fit. The outline of the second limiting slot is adapted to the optical shaft section located between the spline and the bushing on the drive shaft under test and is in clearance fit. Multiple circumferentially distributed air passages are provided on the side wall of the second limiting slot. An air intake channel communicating with the pressurization structure is provided at the bottom of the test slot.

[0014] By adopting the above technical solution, the first and second limiting grooves form clearance fits with the spline section and the optical shaft section of the drive shaft, respectively, thereby achieving precise positioning and alignment of the drive shaft. This ensures that the bushing can be aligned and fitted with the airtight seat in the correct posture, preventing seal failure caused by misalignment during clamping.

[0015] Optionally, the pressurization structure includes a gas source, a gas supply pipeline connected to the gas source, and a pressure control valve disposed on the gas supply pipeline, wherein the outlet of the gas supply pipeline is connected to the test tank.

[0016] By adopting the above technical solution, the pressure control valve can accurately set and adjust the pressure value required for testing.

[0017] Optionally, the pressurization structure further includes a hydraulic auxiliary component, which includes a hydraulic cylinder and a pressurization tank;

[0018] A piston is slidably connected inside the pressurization tank, and the piston divides the inner cavity of the pressurization tank into a reinforcing cavity and an open cavity that communicates with the atmosphere.

[0019] The piston is equipped with a plurality of first one-way valves, the flow direction of the first one-way valves being from the open cavity to the reinforced cavity;

[0020] The pressurization tank is equipped with a second one-way valve, and the enhancement chamber and the test tank are connected through the second one-way valve. The flow direction of the second one-way valve is from the enhancement chamber to the test tank.

[0021] By adopting the above technical solution, the hydraulic cylinder can provide a sufficiently strong thrust to drive the piston to slowly and steadily compress the gas in the enhancement chamber, thereby easily generating a test pressure that is much higher than that of a normal gas source.

[0022] Optionally, the limiting structure includes a retaining clip for holding and securing the drive shaft.

[0023] By adopting the above technical solution and using a fixed buckle as the fixing device, the structure is simple and the operation is convenient.

[0024] Optionally, the limiting structure further includes a lead screw linear module, and the fixing buckle is installed on the slider of the lead screw linear module.

[0025] By adopting the above technical solution, the screw linear module drives the fixed buckle and drive shaft to perform precise vertical lifting and lowering movements, which reduces the labor intensity of operators, improves production efficiency, and, more importantly, ensures the consistency of the depth and speed of each insertion of the airtight seat.

[0026] Optionally, the fixing buckle is rotatably connected to the slider of the lead screw linear module.

[0027] By adopting the above technical solution, for workpieces with bushings at both ends, after one end is tested, rotating the fixing buckle can test the bushing at the other end, further improving testing efficiency.

[0028] In summary, this application includes at least one of the following beneficial technical effects:

[0029] 1. Pressure testing is performed by vertically fixing the drive shaft and inserting the grease-coated bushing end into a sealed test chamber. If a leak is found in the bushing, the overflowing gas will form visible oil film bubbles in the grease between it and the drive shaft, thus accurately locating the leak point. This method is not only intuitive and accurate in judgment, but also completely avoids contact between the workpiece and water, fundamentally eliminating the need for subsequent drying and rust prevention treatments, simplifying the process, and significantly saving production costs and time.

[0030] 2. A lip seal is used, and first and second limiting grooves are set in the test groove to precisely match the spline of the drive shaft and the optical shaft section, forming multiple protections. This technical solution effectively ensures the tight fit between the sealing lip and the outer wall of the bushing under pressure, and also mitigates non-leakage seal failure caused by workpiece clamping misalignment through precise positioning and alignment.

[0031] 3. The basic pressurization structure provides stable and controllable test pressure, while the addition of hydraulic auxiliary components allows the tooling to easily generate higher test pressure. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the overall structure of an embodiment of this application;

[0033] Figure 2 yes Figure 1 A magnified view of part A in the middle;

[0034] Figure 3 This is a schematic diagram illustrating the supercharging structure in an embodiment of this application;

[0035] In the diagram, 1 is the frame; 2 is the airtight seat; 21 is the test slot; 211 is the sealing slot; 212 is the first limiting slot; 213 is the second limiting slot; 214 is the air passage; 215 is the air intake channel; 216 is the lip seal; 3 is the pressurization structure; 31 is the air supply pipeline; 32 is the hydraulic cylinder; 33 is the pressurization tank; 331 is the reinforcing cavity; 332 is the open cavity; 333 is the piston; 334 is the first check valve; 335 is the second check valve; 4 is the limiting structure; 41 is the fixing buckle; 42 is the lead screw linear module; 100 is the drive shaft; 101 is the bushing; 102 is the optical shaft section; and 103 is the spline. Detailed Implementation

[0036] The following is in conjunction with the appendix Figure 1 - Appendix Figure 3 This application will be described in further detail below.

[0037] Example:

[0038] This embodiment provides a tooling for testing the airtightness of the inner ball cage bushing 101 of the drive shaft 100 long rod, referring to... Figures 1-2 The testing fixture includes a frame 1, an airtight seat 2, a pressurizing structure 3, and a limiting structure 4.

[0039] The frame 1 is welded from structural steel, providing a stable support foundation for this tooling.

[0040] Reference Figure 2 The airtight seat 2 is fixedly mounted on the frame 1 by bolts. A vertically downward blind hole is opened in the center of the airtight seat 2 as a test groove 21 to accommodate the bushing 101 part of the drive shaft 100. The test groove 21 includes a sealing groove 211, a second limiting groove 213, and a first limiting groove 212 from top to bottom.

[0041] The diameter of the first limiting groove 212 is slightly larger than the outer ring diameter of the spline 103 of the drive shaft 100. The two form a clearance fit, which mainly plays a role in initial positioning and alignment.

[0042] The diameter of the second limiting groove 213 is slightly larger than the diameter of the optical shaft section 102 between the spline 103 and the bushing 101 on the drive shaft 100. The two also form a clearance fit, which plays a role in precise alignment and ensures that the bushing 101 can enter the sealing area vertically and centered. On the side wall of the second limiting groove 213, four vertical air passages 214 are evenly opened in the circumferential direction. These passages ensure that pressurized gas can quickly fill the entire annular space around the bushing 101.

[0043] The sealing groove 211 is located at the top of the test groove 21, and a lip seal 216 is installed inside it with an interference fit. The outer wall of the lip seal 216 is in close contact with the groove wall of the sealing groove 211, and the sealing lip on its inner side is used to form a dynamic seal with the outer peripheral wall of the inserted bushing 101.

[0044] An air inlet channel 215 is provided at the bottom center of the test tank 21 to connect the pressurization structure 3 to the test tank 21. The pressurization structure 3 delivers compressed gas into the test tank 21 through the air inlet channel. When the test tank 21 is filled with high-pressure gas, the gas pressure acts on the back of the lip seal 216, causing its lip to grip the outer wall of the bushing 101 more tightly, forming a self-sealing effect of "the more pressure, the tighter it gets".

[0045] Reference Figure 3 The pressurization structure 3 is used to provide a stable and controllable test air pressure into the test tank 21. It includes a basic air circuit and hydraulic auxiliary components.

[0046] The basic air circuit includes an air source, an air delivery line 31, and a pressure sensor. The air source can be an air compressor. The end of the air delivery line 31 is connected to the air inlet channel 215 on the airtight seat 2 via a quick connector.

[0047] The hydraulic auxiliary assembly includes a hydraulic cylinder 32 and a pressure tank 33. A piston 333 is slidably connected inside the pressure tank 33, dividing the inner cavity of the pressure tank 33 into a reinforcing chamber 331 and an open chamber 332. Multiple first check valves 334 are embedded in the piston 333, with flow direction from the open chamber 332 to the reinforcing chamber 331. A second check valve 335 is installed at the outlet of the reinforcing chamber 331 of the pressure tank 33. The outlet of the second check valve 335 is connected to the air supply line 31, with flow direction from the reinforcing chamber 331 to the test tank 21.

[0048] The piston rod of the hydraulic cylinder 32 is connected to the piston 333 inside the pressure increasing tank 33. When the hydraulic cylinder 32 acts, it drives the piston 333 to reciprocate: during the return stroke, the volume of the open chamber 332 increases, and atmospheric air is sucked into the pressure increasing chamber 331 through the first one-way valve 334; during the advancing stroke, the piston 333 compresses the gas in the pressure increasing chamber 331, and when the pressure exceeds the pressure in the test tank 21 and the opening pressure of the second one-way valve 335, high-pressure gas is continuously pumped into the test tank 21, so as to achieve gas pressure boosting.

[0049] With reference to Figure 1 , the limiting structure 4 is used to fix the drive shaft 100 during the detection process. The limiting structure 4 includes a fixed buckle 41 fixed above the frame 1 through a bracket. The fixed buckle 41 is a type of quick clamp, whose V-shaped opening can hold and lock the middle part of the drive shaft 100, keeping it in a vertical state with the end of the shaft sleeve 101 facing downward.

[0050] The limiting structure 4 further includes a lead screw linear module 42 mounted above the frame 1 through a bracket. The lead screw linear module 42 is preferably an electric lead screw slide table. The fixed buckle 41 is mounted on the slider of the lead screw linear module 42. This design enables the fixed buckle 41 to be precisely lifted and lowered in the vertical direction along with the slider.

[0051] To further improve the convenience of the test, the fixed buckle 41 is rotatably connected to the slider of the electric lead screw slide table through a bearing, with the rotation axis arranged transversely. For a workpiece provided with shaft sleeves 101 at both ends, after the test of one end is completed, rotating the fixed buckle 41 can test the shaft sleeve 101 at the other end, further improving the test efficiency.

[0052] The working process of the present invention is as follows: an operator places the drive shaft 100 into the fixed buckle 41 and locks it to ensure that the drive shaft 100 is in a vertical state. The lead screw linear module 42 is started to drive the fixed buckle 41 and the drive shaft 100 to descend as a whole, so that the shaft sleeve 101 section is slowly and vertically inserted into the test tank 21 of the airtight seat 2. The first limiting groove 212 and the second limiting groove 213 ensure precise centering of the shaft sleeve 101 until the outer wall of the shaft sleeve 101 forms a seal with the lip of the lip-shaped oil seal 216.

[0053] Gas at a set pressure is charged into the test tank 21 through the basic gas circuit. The hydraulic cylinder 32 is started to drive the piston 333 in the pressure increasing tank 33 to reciprocate, continuously compressing atmospheric air and pumping it into the test tank 21 until the pressure sensor shows that a preset high pressure value is reached.

[0054] After the pressure charging is completed, the pressure maintaining stage is entered. The operator carefully observes whether oil film bubbles are generated at the joint between the shaft sleeve 101 and the drive shaft 100. If continuous or persistently generated bubbles are present, the product is determined to be unqualified in air tightness; otherwise, it is qualified.

[0055] The embodiments described in this specific implementation are preferred embodiments of this application and are not intended to limit the scope of protection of this application. Identical components are represented by the same reference numerals. Therefore, all equivalent changes made to the structure, shape, and principle of this application should be covered within the scope of protection of this application.

Claims

1. A tooling for testing the airtightness of the inner ball cage bushing (101) of a drive shaft (100) long rod, characterized in that: Including rack (1); An airtight seat (2) is fixedly connected to the frame (1). The airtight seat (2) has a test slot (21) for accommodating the drive shaft (100) to be tested. When the drive shaft (100) to be tested is inserted into the test slot (21), the bushing (101) of the drive shaft (100) to be tested is tightly fitted with the airtight seat (2). The pressurization structure (3) is connected to the test tank (21) in the airtight seat (2) and is used to supply gas into the test tank (21) to pressurize the test tank (21); A limiting structure (4) is installed on the frame (1) and is used to fix the drive shaft (100) to be tested; When the limiting structure (4) fixes the drive shaft (100) to be tested, the drive shaft (100) to be tested is set vertically, and the end of the drive shaft (100) to be tested with the bushing (101) is inserted downward into the test groove (21) of the airtight seat (2).

2. The airtightness testing fixture for the inner ball cage bushing (101) of the long rod of the drive shaft (100) according to claim 1, characterized in that: The test groove (21) is provided with a sealing groove (211), and a lip seal (216) is installed in the sealing groove (211). The outer wall of the lip seal (216) is closely fitted with the groove wall of the sealing groove (211), and the inner wall of the lip seal (216) is used to closely fit with the outer peripheral wall of the bushing (101).

3. A tooling for testing the airtightness of the inner ball cage bushing (101) of a drive shaft (100) long rod according to claim 1 or 2, characterized in that: The test slot (21) includes a first limiting slot (212) and a second limiting slot (213) connected sequentially from bottom to top. The outline of the first limiting slot (212) is adapted to the outer ring of the spline (103) of the drive shaft (100) under test and is in clearance fit. The outline of the second limiting slot (213) is adapted to the optical axis section (102) between the spline (103) and the bushing (101) on the drive shaft (100) under test and is in clearance fit. Multiple circumferentially distributed air passages (214) are provided on the side wall of the second limiting slot (213). An air intake channel (215) connected to the pressurization structure (3) is provided at the bottom of the test slot (21).

4. The airtightness testing fixture for the inner ball cage bushing (101) of the long rod of the drive shaft (100) according to claim 1, characterized in that: The pressurization structure (3) includes a gas source, a gas supply pipeline (31) connected to the gas source, and a pressure control valve installed on the gas supply pipeline (31). The outlet of the gas supply pipeline (31) is connected to the test tank (21).

5. The airtightness testing fixture for the inner ball cage bushing (101) of the long rod of the drive shaft (100) according to claim 4, characterized in that: The pressurization structure (3) also includes a hydraulic auxiliary component, which includes a hydraulic cylinder (32) and a pressurization tank (33). A piston (333) is slidably connected inside the pressurizing tank (33), and the piston (333) divides the inner cavity of the pressurizing tank (33) into a reinforcing cavity (331) and an open cavity (332) that communicates with the atmosphere. The piston (333) is equipped with a plurality of first check valves (334), and the flow direction of the first check valves (334) is from the open cavity (332) to the reinforcing cavity (331). The pressurization tank (33) is equipped with a second one-way valve (335). The enhancement chamber (331) and the test tank (21) are connected through the second one-way valve (335). The flow direction of the second one-way valve (335) is from the enhancement chamber (331) to the test tank (21).

6. The airtightness testing fixture for the inner ball cage bushing (101) of the long rod of the drive shaft (100) according to claim 1, characterized in that: The limiting structure (4) includes a retaining buckle (41) for holding and fixing the drive shaft (100).

7. The airtightness testing fixture for the inner ball cage bushing (101) of the long rod of the drive shaft (100) according to claim 6, characterized in that: The limiting structure (4) also includes a lead screw linear module (42), and the fixing buckle (41) is installed on the slider of the lead screw linear module (42).

8. The airtightness testing fixture for the inner ball cage bushing (101) of the long rod of the drive shaft (100) according to claim 7, characterized in that: The fixed buckle (41) is rotatably connected to the slider of the lead screw linear module (42).

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