Gearbox housing oil channel air tightness detection tool and detection method

Abstract

The application relates to the technical field of air tightness detection, and particularly discloses a gear box shell oil channel air tightness detection tool and a detection method. The gear box shell oil channel air tightness detection tool integrates a test table, a mounting seat, a lifting mechanism, a transverse moving mechanism and an air tightness detection mechanism. The automatic collaborative operation mode is as follows: the transverse moving mechanism accurately positions a gear box shell to be detected directly below the mounting seat, and then the lifting mechanism drives the mounting seat and the air tightness detection mechanism to stably descend to a detection position, thereby effectively replacing the complicated steps of traditional manual positioning and mounting of plugs, and significantly improving the overall efficiency and automation level of detection operation. The built-in sealing mechanism ensures that reliable preliminary sealing is formed when the air tightness detection mechanism is connected with the measured oil channel, thereby laying a structural foundation for subsequent accurate detection of the oil channel body leakage.

Description

Technical Field

[0001] This application relates to the field of airtightness testing technology, and in particular to a tooling and testing method for airtightness testing of oil passages in a gearbox housing. Background Technology

[0002] The lubrication channels within the gearbox housing are crucial for the reliable lubrication and cooling of its critical moving parts. Therefore, it is essential to ensure that the channels themselves have excellent airtightness to prevent lubrication failure, component wear, or even safety accidents. This makes rigorous airtightness testing of the housing's oil channels during the manufacturing process an indispensable quality control step.

[0003] Conventional testing methods involve sealing the oil passage by selecting a plug that matches the oil passage opening. For example, the invention patent with publication number CN119147185A discloses a gearbox housing airtightness testing device, which involves introducing high-pressure gas into the sealed oil passage system through one of the plugs, and then determining whether there is a leak in the oil passage by monitoring the gas pressure drop or leakage flow during the pressure holding phase.

[0004] However, this conventional method has a fundamental flaw: the accuracy of its test results is extremely dependent on the sealing reliability of the interface between the plug and the oil passage. If the interface fails to achieve a complete seal due to factors such as insufficient processing precision of the pipe, damage, plug tolerance, or improper installation, the high-pressure gas introduced will leak from the connection point, causing the testing instrument to misjudge that there is a leak in the oil passage body. This may result in a shell with qualified airtightness being mistakenly judged as unqualified, causing unnecessary rework, scrapping, and low testing efficiency. Summary of the Invention

[0005] To overcome the problem of misjudgment caused by poor sealing at the connection between the plug and the oil passage in conventional methods for testing the airtightness of transmission housing oil passages, this application provides a tooling and method for testing the airtightness of transmission housing oil passages.

[0006] This application provides a tooling for testing the airtightness of the oil passages in a gearbox housing, employing the following technical solution:

[0007] A tooling for testing the air tightness of the oil passage of a gearbox housing includes a test bench, a mounting base and a lifting mechanism for driving the mounting base to rise and fall are provided on the test bench surface below the mounting base, and a lateral movement mechanism for driving the gearbox housing to move directly below the mounting base is provided.

[0008] The mounting base is provided with an airtightness testing mechanism for testing the airtightness of the oil passage of the gearbox housing. The testing end of the airtightness testing mechanism is provided with a sealing mechanism for sealing the connection between the testing end and the oil passage of the gearbox housing. The airtightness testing mechanism performs airtightness testing after the sealing mechanism seals the connection.

[0009] By adopting the above technical solution, this gearbox housing oil passage airtightness testing fixture integrates a test bench, mounting base, lifting mechanism, lateral movement mechanism, and airtightness testing mechanism. The automated collaborative operation mode involves the lateral movement mechanism precisely positioning the gearbox housing under test directly below the mounting base, followed by the lifting mechanism driving the mounting base, along with the airtightness testing mechanism, to smoothly descend to the testing position. This effectively replaces the cumbersome steps of traditional manual positioning and plug installation, significantly improving the overall efficiency and automation level of the testing operation. The built-in sealing mechanism ensures a reliable initial seal is formed when the airtightness testing mechanism connects to the oil passage under test, laying the structural foundation for subsequent accurate detection of oil passage leakage.

[0010] Optionally, the sealing mechanism includes a sealing cover, a sealing plug, a sealing ring, and a valve opening structure. The sealing cover includes a venting end and a pressure-holding end. The venting end of the sealing cover is connected to the detection end of the airtightness detection mechanism. The pressure-holding end of the sealing cover is cylindrical and its diameter is larger than the diameter of the oil passage opening of the gearbox housing.

[0011] One end of the sealing plug is fixed inside the sealing cover and seals the inner cavity of the sealing cover, while the other end extends out of the sealing cover and can be slidably and sealably adapted to the inner cavity of the oil passage of the gearbox housing. The sealing ring is movably disposed at the end of the sealing cover away from the detection end of the airtightness detection mechanism. A first elastic telescopic structure is provided between the sealing ring and the inner wall of the sealing cover to allow the sealing ring to move along the length direction of the sealing cover.

[0012] When the sealing cover is placed over the oil passage port of the gearbox housing, the sealing plug extends into the oil passage port of the gearbox housing and seals the oil passage port of the gearbox housing, and the sealing ring seals the gap between the inner wall of the pressure-holding end of the sealing cover and the outer wall of the oil passage port of the gearbox housing.

[0013] The pressure-holding end, the sealing plug, and the sealing ring of the sealing cover form a pressure-holding cavity. A pressure sensor for detecting the air pressure inside the pressure-holding cavity is provided inside the pressure-holding cavity. An air inlet channel connecting the vent end and the pressure-holding cavity and an air outlet channel connecting the pressure-holding cavity and the inner cavity of the oil passage of the gearbox housing are respectively opened in the sealing plug. The valve opening structure is located inside the sealing plug and opens when the pressure sensor value reaches a set value and remains constant.

[0014] By adopting the above technical solution, the sealing mechanism features a unique design with a special sealing cover structure. The larger diameter pressure-holding end completely covers the external area of ​​the oil passage opening. When the tooling descends to its position, the sealing plug inserted into the pipe opening seals the central hole, while the movable sealing ring, under the action of the first elastic telescopic structure, tightly adheres to the outer wall of the pipe opening, completely sealing the annular gap between the inner wall of the sealing cover's pressure-holding end and the outer wall of the pipe opening. This forms a "pressure-holding chamber" independent of the oil passage, enclosed by the sealing cover's pressure-holding end, the sealing plug, and the sealing ring. When high-pressure gas is introduced into the vent through the airtightness testing mechanism, the gas first fills the pressure-holding chamber through the inlet channel, and the pressure sensor monitors the pressure in the chamber in real time. Only after the pressure reaches the set value and stabilizes will the valve opening structure be triggered, opening the outlet channel to the inside of the oil passage. This logically ensures that subsequent tests are always performed on the oil passage itself.

[0015] Optionally, the valve opening structure includes a sealing column and a second elastic telescopic structure. The sealing plug has an installation groove that communicates with the pressure holding chamber. The installation groove communicates with the air outlet channel. The sealing plug is slidably and sealingly installed in the installation groove and seals and separates the pressure holding chamber and the air outlet channel.

[0016] A sealing channel is provided inside the sealing column. One end of the sealing channel passes through the sealing column and communicates with the pressure-holding cavity, and the other end passes through the inner wall of the sealing column. The second elastic telescopic structure is disposed in the mounting groove and can provide the sealing column with a sliding force into the pressure-holding cavity. When the pressure sensor value reaches the set value and remains constant, the airtightness detection mechanism gradually pushes the sealing column until the sealing channel connects the pressure-holding cavity and the air outlet channel.

[0017] By adopting the above technical solution, the valve opening structure achieves automatic triggering through ingenious mechanical design. Under the action of the second elastic telescopic structure, the sealing column, by default, isolates the mounting groove, thus physically blocking the connection between the pressure-holding chamber and the air outlet channel. When the pressure in the pressure-holding chamber gradually rises to the set value and remains stable, the airtightness detection mechanism immediately introduces high-pressure gas, overcoming the resistance of the second elastic telescopic structure and pushing the sealing column to slide within the mounting groove. This continues until the sealing channel within the sealing column is accurately aligned and connects the pressure-holding chamber and the air outlet channel, allowing high-pressure gas to formally enter the tested oil passage. This structure features reliable mechanical linkage, effectively enforcing the step-by-step operation process of "first verifying the interface seal, then detecting oil passage leakage."

[0018] Optionally, the first elastic telescopic structure includes a first telescopic rod and a first elastic element sleeved on the first telescopic rod. One end of the first telescopic rod is fixedly connected to the inner wall of the pressure-holding end, and the other end is fixedly connected to the sealing ring. The first elastic element is used to provide the sealing ring with a force to move towards the outlet of the pressure-holding cavity.

[0019] The second elastic telescopic structure includes a second telescopic rod and a second elastic element sleeved on the second telescopic rod. The second telescopic rod is located in the mounting groove, with one end fixedly connected to the inner wall of the mounting groove and the other end fixedly connected to the end of the sealing column. The second elastic element is used to provide a force for the sealing column to move out of the mounting groove.

[0020] By adopting the above technical solution, the first elastic telescopic structure is specifically guided and bears tension / compression by the first telescopic rod, while the first elastic element continuously provides elastic force to press the sealing ring against the outer wall of the pipe opening, ensuring that the sealing ring can effectively compensate for the micro-dimensional differences or minor defects of different pipe openings and maintain the reliability of the annular gap seal. The second elastic telescopic structure is also precisely guided and bears load by the second telescopic rod, relying on the thrust of the second elastic element to maintain the sealing column in the default position. Simultaneously, its reaction force design ensures that the sealing column requires precise external force to move and open the valve, resulting in stable and controllable operation.

[0021] Optionally, the inner wall of the pressure-holding end of the sealing cover is inclined, and the wall thickness of the sealing cover gradually increases from the venting end near the sealing cover to the venting end away from the sealing cover.

[0022] By adopting the above technical solution, the inclined inner wall design significantly increases the effective contact area with the movable sealing ring and can guide and correct the posture of the sealing ring, further improving the stability of the annular gap seal and its ability to adapt to pipe manufacturing tolerances. The gradual increase in wall thickness enhances the structural strength and rigidity of the distal end of the pressure-holding cavity, ensuring that it is not easily deformed under high pressure and maintaining the geometric stability of the sealing interface.

[0023] Optionally, multiple support blocks are fixed circumferentially at intervals on the inner wall of the pressure-holding end of the sealing cover, and each support block is used to support the end of the oil passage port of the gearbox housing.

[0024] By adopting the above technical solution, when the sealing cover descends and covers the oil passage opening, these support blocks first contact the end face of the opening, undertaking the main load-bearing and precise positioning functions, thus preventing the sealing ring and sealing plug from being directly subjected to excessive impact or pressure and damaged. This not only protects the sealing elements, but more importantly, ensures that the relative position of the sealing cover and the opening remains horizontal and aligned, allowing the sealing ring to be evenly compressed on the outer wall of the opening, achieving a uniform and reliable seal. Furthermore, a gap is reserved between the oil passage opening of the gearbox housing and the inner wall of the pressure-holding end for gas passage, ensuring a constant gas pressure throughout the pressure-holding chamber.

[0025] Optionally, the airtightness testing mechanism includes a high-pressure pipe and a solenoid valve. Multiple high-pressure pipes and solenoid valves are provided. Each high-pressure pipe is connected to the vent end of the corresponding sealing cover. Each solenoid valve is located inside the corresponding high-pressure pipe. Each high-pressure pipe is connected to an external high-pressure air pump.

[0026] By adopting the above technical solution, multiple high-pressure pipes are connected to corresponding sealing covers, each with an independently installed solenoid valve, and ultimately connected to an external high-pressure air source. This architecture allows the tooling to simultaneously perform parallel pressurization, pressure holding, and leak detection on oil passages at multiple different locations on the gearbox housing. The independent on / off control of the solenoid valves precisely manages the start of pressurization, the start of the pressure holding phase, and possible depressurization processes for each oil passage, achieving process independence for multi-point detection and significantly improving detection efficiency.

[0027] This application also provides a method for testing the airtightness of the oil passage in a gearbox housing, including the following steps:

[0028] S1: Fix the gearbox housing onto the transverse mechanism, and control the transverse mechanism to move the gearbox housing directly below the mounting base;

[0029] S2: The lifting mechanism drives the mounting base to descend until the inner wall of the pressure-holding end of the sealing cover abuts against the end of the oil passage in the gearbox housing;

[0030] S3: Turn on the external high-pressure air pump until the pressure sensor value reaches the set value, then turn off the external high-pressure air pump and monitor the pressure sensor value.

[0031] S4: Obtain the value of the pressure sensor. If the value of the pressure sensor remains unchanged within a specified time, continue to turn on the high-pressure air pump to perform an airtightness test on the oil passage of the gearbox housing. If the value of the pressure sensor drops within a specified time, check the sealing performance between the pressure-holding end of the sealing cover and the end of the oil passage of the gearbox housing. Continue to perform the airtightness test until the value of the pressure sensor no longer drops within a fixed time.

[0032] S5: Obtain the detection structure of the airtightness testing mechanism to determine the airtightness of the transmission oil passage.

[0033] By employing the above method, the testing process is systematically divided into two closely related core stages. First, after the tooling is in place and sealed, the "connection interface sealing verification (S3-S4 first half)" is performed: pressure is applied to the pressure-holding chamber to the set value and held, and pressure sensor data is monitored to determine whether the double seal formed by the sealing plug and the inner wall of the pipe, and the sealing ring and the outer wall of the pipe, is completely reliable. Only after the pressure stabilizes in this stage does the second stage, "oil passage airtightness testing (S4 second half-S5)," begin: the valve opening structure is triggered, formally introducing high-pressure gas into the tested oil passage, followed by pressure holding and leakage detection. This step-by-step method completely eliminates the interference of connection leakage on the judgment of oil passage leakage in traditional methods, ensuring that any detected pressure drop is necessarily caused by actual leakage in the oil passage itself or its internal interface, significantly improving the absolute accuracy and reliability of the test results and eliminating misjudgments.

[0034] In summary, this application includes at least one of the following beneficial technical effects:

[0035] 1. This application designs a dedicated integrated tooling and testing method, which successfully pre-processes and automates the verification of the sealing reliability of the connection interface. Specifically, the unique sealing mechanism added to the tooling constructs a physically isolated "pre-pressure holding chamber" at the oil passage opening. Before the test gas is introduced into the oil passage body, the chamber is pressurized and pressure-held for monitoring. This design allows any leakage at the connection caused by defects in the pipe opening processing, damage, or improper installation of the sealing element to be identified and eliminated in real time before the formal oil passage airtightness test begins. This fundamentally solves the problem of systematic misjudgment caused by the inability of the traditional plug-type testing method to distinguish between leakage at the connection and leakage in the oil passage body. It significantly reduces the risk of qualified products being incorrectly rejected, avoids unnecessary rework and scrap, and improves the accuracy and reliability of the test.

[0036] 2. The sealing mechanism of this invention adopts an innovative dual-channel sealing and mechanical trigger linkage structure. Utilizing the synergistic effect of a sealing plug deeply embedded inside the oil passage and an elastic sealing ring surrounding the outside of the passage, a double-safety seal is achieved at the connection interface, forming an independent and closed pre-pressure-holding chamber. More importantly, before the sealing performance of the pressure-holding chamber itself is verified, the passage to the inside of the oil passage is mechanically blocked by the valve-opening structure. This mechanical interlock design mandates that the successful sealing verification of the pressure-holding chamber is the sole prerequisite for the next step of testing the oil passage itself, ensuring the rigorous execution of the testing logic sequence. This completely eliminates the possibility of human error or instrument misjudgment causing logical chaos in the testing process, greatly enhancing the automation, standardization, and traceability of the testing process.

[0037] 3. The detection method and tooling system of this invention deeply integrate automated positioning and multi-point parallel detection capabilities. By integrating lifting mechanism, lateral movement mechanism and independent sealing and detection channels for multiple oil passage ports, it realizes the precise positioning and rapid docking of the gearbox housing on the tooling, as well as the synchronous or independent pressurization, pressure holding and leakage monitoring of multiple oil passages. This highly integrated automated system significantly reduces manual intervention steps and positioning time, greatly improves detection cycle and overall efficiency, and completely changes the inefficient detection mode of traditional methods of installing plugs, sealing and pressurizing one by one. It can also adapt to the detection needs of housings with different specifications and complex oil passage layouts.

[0038] 4. The airtightness test of this application can only be carried out if there is no leakage in the "pre-pressure chamber". Otherwise, the test cannot be carried out, which ensures the accuracy of the test results. Moreover, the pressure environment of the "pre-pressure chamber" is the same as the pressure environment during the airtightness test. Compared with the general sealing structure, the sealing structure in this application can simulate the pressure during the airtightness test at the connection, ensuring that the sealing structure can remain sealed during the airtightness test. Attached Figure Description

[0039] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0040] Figure 1 This is a schematic diagram of the overall structure of a gearbox housing oil passage air tightness testing tool according to an embodiment of this application;

[0041] Figure 2 yes Figure 1 A schematic diagram of the structure of a gearbox housing oil passage air tightness testing tool from the bottom view;

[0042] Figure 3 yes Figure 2 Schematic diagram of the structure at the mounting base;

[0043] Figure 4 yes Figure 3 A cross-sectional view of the central sealing mechanism.

[0044] Reference numerals: 1. Test stand; 11. Mounting base; 2. Lifting mechanism; 3. Lateral movement mechanism; 4. Air tightness testing mechanism; 5. Sealing mechanism; 51. Sealing cover; 511. Vent end; 512. Pressure holding end; 513. Support block; 52. Sealing plug; 521. Air inlet channel; 522. Air outlet channel; 53. Sealing ring; 54. Valve opening structure; 541. Sealing column; 5411. Sealing channel; 542. Second elastic telescopic structure; 6. Pressure holding chamber; 7. First elastic telescopic structure. Detailed Implementation

[0045] The following is in conjunction with the appendix Figure 1-4 This application will be described in further detail below.

[0046] This application discloses a tooling for testing the airtightness of the oil passage in a gearbox housing.

[0047] A tooling for testing the airtightness of the oil passages in a gearbox housing, referring to... Figure 1 and Figure 2 It includes a test bench 1, a mounting base 11 and a lifting mechanism 2 for driving the mounting base 11 to rise and fall, and a transverse mechanism 3 for driving the gearbox housing to move directly below the mounting base 11 on the test bench 1 surface below the mounting base 11.

[0048] The mounting base 11 is provided with an airtightness testing mechanism 4 for testing the airtightness of the oil passage of the gearbox housing. The testing end of the airtightness testing mechanism 4 is provided with a sealing mechanism 5 for sealing the connection between the testing end and the oil passage of the gearbox housing. After the airtightness testing mechanism 4 and the sealing mechanism 5 seal the connection, the airtightness testing mechanism 4 performs the airtightness test.

[0049] This gearbox housing oil passage airtightness testing fixture integrates a test bench 1, a mounting base 11, a lifting mechanism 2, a lateral movement mechanism 3, and an airtightness testing mechanism 4. In an automated, coordinated operation, the lateral movement mechanism 3 precisely positions the gearbox housing under test directly below the mounting base 11. The lifting mechanism 2 then drives the mounting base 11, along with the airtightness testing mechanism 4, to smoothly descend to the testing position. This effectively replaces the cumbersome steps of traditional manual positioning and plug installation, significantly improving the overall efficiency and automation level of the testing operation. The built-in sealing mechanism 5 ensures a reliable initial seal is formed when the airtightness testing mechanism 4 connects to the oil passage under test, laying the structural foundation for subsequent accurate detection of leaks in the oil passage itself (rather than leaks at the connection point).

[0050] The transverse mechanism 3 uses a linear motor, and a fixed seat is fixed on the transverse seat of the linear motor. The gearbox housing can be fixed on the fixed seat. The lifting mechanism 2 uses an electric telescopic rod, and the telescopic end of the electric telescopic rod is fixedly connected to the mounting base 11.

[0051] Reference Figure 3 and Figure 4 The sealing mechanism 5 includes a sealing cover 51, a sealing plug 52, a sealing ring 53, and a valve opening structure 54. The sealing cover 51 includes a vent end 511 and a pressure holding end 512. The vent end 511 of the sealing cover 51 is connected to the detection end of the airtightness detection mechanism 4. The pressure holding end 512 of the sealing cover 51 is cylindrical and its diameter is larger than the diameter of the oil passage port of the gearbox housing.

[0052] One end of the sealing plug 52 is fixed inside the sealing cover 51 and seals and separates the inner cavity of the sealing cover 51. The other end extends out of the sealing cover 51 and can be slidably sealed and adapted to the inner cavity of the oil passage of the gearbox housing. The sealing ring 53 is movably disposed at the end of the sealing cover 51 away from the detection end of the airtightness detection mechanism 4. A first elastic telescopic structure 7 is provided between the sealing ring 53 and the inner wall of the sealing cover 51 to allow the sealing ring 53 to move along the length direction of the sealing cover 51.

[0053] When the sealing cover 51 is placed over the oil passage opening of the gearbox housing, the sealing plug 52 extends into the oil passage opening of the gearbox housing and seals the oil passage opening of the gearbox housing, and the sealing ring 53 seals the gap between the inner wall of the pressure-holding end 512 of the sealing cover 51 and the outer wall of the oil passage opening of the gearbox housing.

[0054] Reference Figure 3 and Figure 4 The pressure-holding end 512 of the sealing cover 51, the sealing plug 52 and the sealing ring 53 form a pressure-holding cavity 6. A pressure sensor for detecting the air pressure in the pressure-holding cavity 6 is provided in the pressure-holding cavity 6. The sealing plug 52 is provided with an air inlet channel 521 that connects the air outlet 511 and the pressure-holding cavity 6, and an air outlet channel 522 that connects the pressure-holding cavity 6 and the inner cavity of the oil passage of the gearbox housing. The valve opening structure 54 is located in the sealing plug 52 and opens when the pressure sensor value reaches the set value and remains constant.

[0055] The sealing mechanism 5 has a unique design, with a special structure for its sealing cover 51. The larger diameter pressure-holding end 512 can completely cover the external area of ​​the oil passage opening. When the tooling is lowered into place, the sealing plug 52 inserted into the pipe opening achieves a central hole seal, while the movable sealing ring 53, under the action of the first elastic telescopic structure 7, tightly adheres to the outer wall of the pipe opening, completely sealing the annular gap between the inner wall of the pressure-holding end 512 of the sealing cover 51 and the outer wall of the pipe opening. This forms a "pressure-holding cavity 6" that is independent of the oil passage and is surrounded by the pressure-holding end 512 of the sealing cover 51, the sealing plug 52, and the sealing ring 53.

[0056] When high-pressure gas is introduced into the vent 511 through the airtightness testing mechanism 4, the gas first fills the pressure holding chamber 6 through the air intake channel 521, and the pressure sensor monitors the pressure in the pressure holding chamber 6 in real time. Only after the pressure reaches the set value and stabilizes will the valve opening structure 54 be triggered to open the air outlet channel 522 leading to the inside of the oil passage, thereby ensuring in the logical sequence that subsequent tests are necessarily aimed at the oil passage body.

[0057] Reference Figure 3 and Figure 4 The valve opening structure 54 includes a sealing column 541 and a second elastic telescopic structure 542. The sealing plug 52 has an installation groove that communicates with the pressure holding chamber 6. The installation groove communicates with the air outlet channel 522. The sealing plug 52 is slidably and sealingly installed in the installation groove and seals and separates the pressure holding chamber 6 and the air outlet channel 522.

[0058] A sealing channel 5411 is provided inside the sealing column 541. One end of the sealing channel 5411 passes through the sealing column 541 and communicates with the pressure holding chamber 6, and the other end passes through the inner wall of the sealing column 541. The second elastic telescopic structure 542 is set in the mounting groove and can provide the sealing column 541 with a sliding force into the pressure holding chamber 6. When the pressure sensor value reaches the set value and remains constant, the airtightness detection mechanism 4 gradually pushes the sealing column 541 until the sealing channel 5411 connects the pressure holding chamber 6 and the air outlet channel 522.

[0059] The valve opening structure 54 achieves automatic triggering through ingenious mechanical design. Under the action of the second elastic telescopic structure 542, the sealing column 541, by default, isolates the mounting groove, thus physically blocking the connection between the pressure-holding chamber 6 and the air outlet channel 522. When the pressure in the pressure-holding chamber 6 gradually increases to the set value and remains stable, the airtightness detection mechanism 4 immediately introduces high-pressure gas, overcoming the resistance of the second elastic telescopic structure 542 and pushing the sealing column 541 to slide within the mounting groove. This continues until the sealing channel 5411 within the sealing column 541 is accurately aligned and connects the pressure-holding chamber 6 and the air outlet channel 522, allowing high-pressure gas to formally enter the tested oil passage. This structure features reliable mechanical linkage, effectively enforcing the step-by-step operation process of "first verifying the interface seal, then detecting oil passage leakage."

[0060] Reference Figure 3 and Figure 4 The first elastic telescopic structure 7 includes a first telescopic rod and a first elastic element sleeved on the first telescopic rod. One end of the first telescopic rod is fixedly connected to the inner wall of the pressure-holding end 512, and the other end is fixedly connected to the sealing ring 53. The first elastic element is used to provide a force for the sealing ring 53 to move in the direction of the outlet of the pressure-holding cavity 6.

[0061] Reference Figure 3 and Figure 4 The second elastic telescopic structure 542 includes a second telescopic rod and a second elastic element sleeved on the second telescopic rod. The second telescopic rod is located in the mounting groove, and one end is fixedly connected to the inner wall of the mounting groove, and the other end is fixedly connected to the end of the sealing column 541. The second elastic element is used to provide a force for the sealing column 541 to move out of the mounting groove.

[0062] The first elastic telescopic structure 7 is specifically guided and bears tension / compression by the first telescopic rod, while the first elastic element continuously provides elastic force to press the sealing ring 53 against the outer wall of the pipe opening, ensuring that the sealing ring 53 can effectively compensate for the micro-dimensional differences or minor defects of different pipe openings and maintain the reliability of the annular gap seal. The second elastic telescopic structure 542 is also precisely guided and supported by the second telescopic rod, relying on the thrust of the second elastic element to maintain the sealing state of the sealing column 541 in the default position. At the same time, its reaction force design ensures that the sealing column 541 requires precise external force to move and open the valve, making its operation stable and controllable.

[0063] The inner wall of the pressure-holding end 512 of the sealing cover 51 is inclined, and the wall thickness of the sealing cover 51 gradually increases from the venting end 511 near the sealing cover 51 to the venting end 511 away from the sealing cover 51. The inclined inner wall design significantly increases the effective contact area with the movable sealing ring 53 and can guide and correct the posture of the sealing ring 53, further improving the stability of the annular gap seal and its ability to adapt to pipe manufacturing tolerances. The gradual increase in wall thickness enhances the structural strength and rigidity of the distal end of the pressure-holding cavity 6, ensuring that it is not easily deformed under high air pressure and maintaining the geometric stability of the sealing interface.

[0064] Multiple support blocks 513 are fixed circumferentially at intervals on the inner wall of the pressure-holding end 512 of the sealing cover 51. Each support block 513 is used to support the end of the oil passage port of the gearbox housing. When the sealing cover 51 descends and covers the oil passage port, these support blocks 513 first contact the end face of the port, bearing the main load and precise positioning function, preventing the sealing ring 53 and sealing plug 52 from being directly subjected to excessive impact or pressure and thus being damaged. This not only protects the sealing elements, but more importantly, it ensures that the relative position of the sealing cover 51 and the port remains horizontal and aligned, allowing the sealing ring 53 to be evenly compressed on the outer wall of the port, achieving a uniform and reliable seal. Furthermore, a gap is reserved between the oil passage port of the gearbox housing and the inner wall of the pressure-holding end 512 for gas to pass through, keeping the gas pressure constant throughout the pressure-holding chamber 6.

[0065] The airtightness testing mechanism 4 includes a high-pressure pipe and a solenoid valve. Multiple high-pressure pipes and solenoid valves are provided. Each high-pressure pipe is connected to the vent end 511 of the corresponding sealing cover 51. Each solenoid valve is located inside the corresponding high-pressure pipe. Each high-pressure pipe is connected to an external high-pressure air pump.

[0066] Multiple high-pressure pipes are connected to corresponding sealing covers 51, each with an independently installed solenoid valve, and ultimately connected to an external high-pressure air source. This architecture allows the fixture to simultaneously pressurize, hold, and detect leaks in multiple oil passages at different locations on the gearbox housing. The independent on / off control of the solenoid valves precisely manages the start of pressurization, the start of the holding phase, and any potential depressurization processes in each oil passage, achieving process independence for multi-point detection and significantly improving detection efficiency.

[0067] The implementation principle of the gearbox housing oil passage air tightness testing tool in this application embodiment is as follows: the gearbox housing to be tested is precisely positioned directly below the mounting base 11 by the transverse mechanism 3, and then the lifting mechanism 2 drives the mounting base 11 to descend as a whole, causing the pressure-holding end 512 of the sealing cover 51 to completely cover the oil passage opening.

[0068] At this moment, the sealing plug 52 set inside the sealing cover 51 is pressed into the inner cavity of the oil passage to form a central hole seal, while the movable sealing ring 53 is continuously pushed by the first elastic telescopic structure 7, tightly fitting the annular gap between the outer wall of the pipe opening and the inner wall of the pressure-holding end 512 to form an outer ring seal. The two work together to physically construct an independent and closed pre-pressure-holding cavity 6 between the sealing plug 52, the pressure-holding end 512 and the sealing ring 53.

[0069] At this time, the air tightness testing mechanism 4 introduces high-pressure gas into the pressure holding chamber 6 through the high-pressure pipe. The pressure sensor monitors the gas pressure in the chamber in real time. If the pressure remains stable during the pressure holding stage, it can be verified that the connection interface between the tooling and the oil passage is sealed reliably without leakage.

[0070] This verification result serves as a necessary condition for triggering the next step of testing: when the pressure in the pressure-holding chamber 6 reaches the set value and stabilizes, the airtightness testing mechanism 4 activates the external drive device to apply axial thrust to the valve opening structure 54, overcome the resistance of the second elastic telescopic structure 542, and push the sealing column 541 to precisely displace in the mounting groove until its internal sealing channel 5411 connects the pressure-holding chamber 6 with the previously physically isolated air outlet channel 522. At this time, high-pressure gas enters the transmission oil passage for the first time.

[0071] The system then monitors pressure changes within the oil passage using a conventional pressure-holding method. Since the upstream process has completely eliminated leakage interference at the connection interface, any pressure drop can be attributed to a real defect in the oil passage body or its internal joints. Meanwhile, the entire process relies on a parallel air circuit system controlled by lifting mechanism 2, lateral movement mechanism 3, and multiple independent solenoid valves to achieve automatic housing positioning and simultaneous detection of multiple oil passages. The support block 513 structure provides contact reference and protection. Finally, through phased verification and mechanical interlock triggering mechanisms, it is ensured that the detection results only reflect the true airtightness of the oil passage body.

[0072] This application also discloses a method for testing the airtightness of the oil passage in a gearbox housing, including the following steps:

[0073] S1: Fix the gearbox housing onto the transverse mechanism 3, and control the transverse mechanism 3 to move the gearbox housing directly below the mounting base 11;

[0074] S2: The lifting mechanism 2 drives the mounting base 11 to descend until the inner wall of the pressure-holding end 512 of the sealing cover 51 abuts against the end of the oil passage of the gearbox housing;

[0075] S3: Turn on the external high-pressure air pump until the pressure sensor value reaches the set value, then turn off the external high-pressure air pump and monitor the pressure sensor value.

[0076] S4: Obtain the value of the pressure sensor. If the value of the pressure sensor remains unchanged within a specified time, continue to turn on the high-pressure air pump to perform an airtightness test on the oil passage of the gearbox housing. If the value of the pressure sensor drops within a specified time, check the connection sealing between the pressure-holding end 512 of the sealing cover 51 and the end of the oil passage of the gearbox housing. Continue to perform the airtightness test until the value of the pressure sensor no longer drops within a fixed time.

[0077] S5: Obtain the detection structure of the airtightness detection mechanism 4 to determine the airtightness of the transmission oil passage.

[0078] Unless otherwise defined, the technical or scientific terms used in this application shall have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The terms "first," "second," "third," and similar words used in this application specification and claims do not indicate any order, quantity, or importance, but are merely used to distinguish different components. The terms "a" or "an," and similar words do not indicate a quantity limitation, but rather indicate the presence of at least one. The terms "comprising," "including," and similar words mean that the elements or objects preceding "comprising" or "including" encompass the elements or objects listed following "comprising" or "including" and their equivalents, but do not exclude other elements or objects. "Above," "below," "left," "right," etc., are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0079] The above are all optional embodiments of this application and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A gear box housing oil passage airtightness detection tool, characterized in that: The test bench (1) is provided with a mounting seat (11) and a lifting mechanism (2) for driving the mounting seat (11) to lift, and the test bench (1) is provided with a horizontal moving mechanism (3) for driving the gearbox shell to move to the position right below the mounting seat (11); The mounting seat (11) is provided with an air tightness detection mechanism (4) for detecting the air tightness of the gearbox oil channel, and the detection end of the air tightness detection mechanism (4) is provided with a sealing mechanism (5) for sealing the connection between the detection end and the gearbox oil channel, and the air tightness detection mechanism (4) detects the air tightness after the sealing mechanism (5) seals the connection. The sealing mechanism (5) comprises a sealing cover (51), a sealing plug (52), a sealing ring (53) and an opening valve structure (54), the sealing cover (51) comprises an air inlet end (511) and a pressure maintaining end (512), the air inlet end (511) of the sealing cover (51) is communicated with the detection end of the air tightness detection mechanism (4), and the pressure maintaining end (512) of the sealing cover (51) is in a cylindrical shape and has a diameter larger than that of the gearbox oil channel pipe. One end of the sealing plug (52) is fixed in the sealing cover (51) and seals the inner cavity of the sealing cover (51), the other end of the sealing plug (52) partially extends out of the sealing cover (51) and can be slidably sealed with the inner cavity of the gearbox oil channel pipe, the sealing ring (53) is movably arranged at the end of the sealing cover (51) away from the detection end of the air tightness detection mechanism (4), and a first elastic extension structure (7) is arranged between the sealing ring (53) and the inner wall of the sealing cover (51) for enabling the sealing ring (53) to move along the length direction of the sealing cover (51). When the sealing cover (51) covers the gearbox oil channel pipe, the sealing plug (52) extends into the gearbox oil channel pipe and seals the gearbox oil channel pipe, and the sealing ring (53) seals the gap between the inner wall of the pressure maintaining end (512) of the sealing cover (51) and the outer wall of the gearbox oil channel pipe. The pressure maintaining end (512) of the sealing cover (51), the sealing plug (52) and the sealing ring (53) form a pressure maintaining cavity (6) therearound, a pressure sensor for detecting the air pressure in the pressure maintaining cavity (6) is arranged in the pressure maintaining cavity (6), air inlet channels (521) and air outlet channels (522) are respectively arranged in the sealing plug (52) and communicated with the air inlet end (511) and the pressure maintaining cavity (6), and the opening valve structure (54) is arranged in the sealing plug (52) and opens when the value of the pressure sensor is constant.

2. The oil passage airtightness detection tool for a gearbox housing according to claim 1, characterized in that: The opening valve structure (54) comprises a sealing column (541) and a second elastic telescopic structure (542), an installation groove in communication with the pressure maintaining cavity (6) is formed in the sealing plug (52), the installation groove is in communication with the gas outlet channel (522), the sealing plug (52) is slidingly and sealingly installed in the installation groove and separates the pressure maintaining cavity (6) and the gas outlet channel (522); A sealing channel (5411) is formed in the sealing column (541), one end of the sealing channel (5411) penetrates through the sealing column (541) and is in communication with the pressure maintaining cavity (6), the other end penetrates through the inner wall of the sealing column (541), the second elastic telescopic structure (542) is arranged in the installation groove and can provide an action force for the sealing column (541) to slide into the pressure maintaining cavity (6), when the pressure sensor value reaches a set value and is constant, the air tightness detection mechanism (4) gradually pushes the sealing column (541) until the sealing channel (5411) connects the pressure maintaining cavity (6) and the gas outlet channel (522).

3. The oil passage airtightness detection tool for a gearbox housing according to claim 2, characterized in that: The first elastic telescopic structure (7) comprises a first telescopic rod and a first elastic member sleeved on the first telescopic rod, one end of the first telescopic rod is fixedly connected with the inner wall of the pressure maintaining end (512), the other end is fixedly connected with the sealing ring (53), and the first elastic member is used for providing an action force for the sealing ring (53) to move to the outlet direction of the pressure maintaining cavity (6); The second elastic telescopic structure (542) comprises a second telescopic rod and a second elastic member sleeved on the second telescopic rod, the second telescopic rod is located in the installation groove and one end thereof is fixedly connected with the inner wall of the installation groove, the other end is fixedly connected with the end of the sealing column (541), and the second elastic member is used for providing an action force for the sealing column (541) to move out of the installation groove.

4. The oil passage airtightness detection tool for a gearbox housing according to claim 1, characterized in that: The inner wall of the pressure maintaining end (512) of the sealing cover (51) is arranged in an inclined manner, and the wall thickness of the sealing cover (51) gradually increases from the air passage end (511) close to the sealing cover (51) to the air passage end (511) away from the sealing cover (51).

5. The oil passage airtightness detection tool for a gearbox housing according to claim 1, characterized in that: A plurality of support blocks (513) are fixedly arranged on the inner wall of the pressure maintaining end (512) of the sealing cover (51) in a circumferential direction, and each support block (513) is used for supporting the end of the gearbox housing oil way pipe.

6. The oil passage airtightness detection tool for a gearbox housing according to claim 1, characterized in that: The air tightness detection mechanism (4) comprises a plurality of high-pressure pipes and a plurality of electromagnetic valves, each high-pressure pipe is in communication with the air passage end (511) of the corresponding sealing cover (51), each electromagnetic valve is arranged in the corresponding high-pressure pipe, and each high-pressure pipe is in communication with an external high-pressure air pump.

7. A gearbox housing oil way air tightness detection method, which adopts the gearbox housing oil way air tightness detection tool in any one of claims 1-6 to perform detection, and comprises the following steps: S1: fixing and installing the gearbox housing on the horizontal moving mechanism (3), and controlling the horizontal moving mechanism (3) to drive the gearbox housing to move to the position directly below the installation seat (11); S2: The lifting mechanism (2) drives the mounting seat (11) to descend until the inner wall of the pressure maintaining end (512) of the sealing cover (51) abuts against the end of the oil passage pipe of the gearbox housing; S3: The external high-pressure air pump is opened until the value of the pressure sensor reaches the set value, at which time the external high-pressure air pump is closed, and the value of the pressure sensor is monitored; S4: The value of the pressure sensor is obtained, if the value of the pressure sensor remains unchanged within a specified time, the high-pressure air pump is continuously opened, the air tightness of the oil passage of the gearbox housing is detected, if the value of the pressure sensor decreases within a specified time, the connection tightness between the pressure maintaining end (512) of the sealing cover (51) and the end of the oil passage pipe of the gearbox housing is checked, until the value of the pressure sensor no longer decreases within a fixed time, that is, the air tightness detection can be continued; S5: The detection structure of the air tightness detection mechanism (4) is obtained, and the air tightness of the gearbox oil passage is judged.

Images