Gearbox shell oil duct air tightness detection tool and detection method

Abstract

The invention relates to the technical field of air tightness detection, and particularly discloses a gearbox shell oil duct air tightness detection tool and a detection method. The gearbox shell oil duct air tightness detection tool integrates a test board, a mounting seat, a lifting mechanism, a transverse moving mechanism and an air tightness detection mechanism. According to an automatic cooperative operation mode, a gearbox shell to be detected is accurately positioned under the mounting seat by the transverse moving mechanism, and then the mounting seat and the air tightness detection mechanism are driven by the lifting mechanism to stably descend to a detection position, so that the tedious steps of traditional manual positioning and plug mounting are effectively replaced; and the overall efficiency and the automation level of the detection operation are obviously improved. The built-in sealing mechanism ensures that reliable preliminary sealing is formed when the air tightness detection mechanism is connected with the oil duct to be detected, and a structural foundation is laid for follow-up accurate detection of leakage of the oil duct body.

Description

Technical Field

[0001] The present application relates to the technical field of air tightness detection, and in particular to a tool and method for detecting air tightness of an oil channel of a gearbox housing. Background Art

[0002] The lubrication oil passages within the gearbox housing are crucial for reliable lubrication and cooling of its key internal moving parts. Therefore, it is imperative to ensure that the oil passages themselves have excellent airtightness to prevent lubrication failure, component wear, and even safety accidents. This dictates that strict airtightness testing of the housing oil passages during the manufacturing process is an essential quality control step.

[0003] The conventional detection method is to seal the oil channel by selecting a plug that matches the oil channel opening. For example, the invention patent with publication number CN119147185A discloses a gearbox housing air tightness detection device, which is to pass high-pressure gas into the sealed oil channel system through one of the plugs, and then determine whether there is a leak in the oil channel by monitoring the gas pressure drop or leakage flow during the pressure holding stage.

[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 channel pipe mouth. If the interface fails to achieve complete sealing due to factors such as insufficient pipe mouth processing accuracy, damage, plug tolerance or improper installation, the introduced high-pressure gas will leak from the connection, causing the detection instrument to mistakenly determine that there is a leak in the oil channel body, and thus may mistakenly determine that the shell that meets the airtightness requirements is unqualified, resulting in unnecessary rework, scrapping and low detection efficiency. Summary of the Invention

[0005] In order to overcome the misjudgment problem caused by poor sealing at the connection between the plug and the oil channel pipe opening in the conventional transmission housing oil channel air tightness detection method, the present application provides a transmission housing oil channel air tightness detection tool and detection method.

[0006] This application provides a gearbox housing oil channel air tightness detection tool, which adopts the following technical solutions: A gearbox housing oil channel air tightness testing tool comprises a test bench, a mounting seat and a lifting mechanism for driving the mounting seat to rise and fall are provided above the test bench, and a transverse movement mechanism for driving the gearbox housing to move directly below the mounting seat is provided on the test bench surface below the mounting seat; The mounting seat is provided with an air tightness detection mechanism for performing air tightness detection on the transmission housing oil channel. The detection end of the air tightness detection mechanism is provided with a sealing mechanism for sealing the connection between the detection end and the transmission housing oil channel. The air tightness detection mechanism performs air tightness detection after the sealing mechanism seals the connection.

[0007] By adopting the above-mentioned technical solution, the gearbox housing oil channel air-tightness test tool integrates a test bench, a mounting base, a lifting mechanism, a transverse mechanism, and an air-tightness test mechanism. This automated collaborative operation uses the transverse mechanism to precisely position the gearbox housing under test directly below the mounting base. The lifting mechanism then drives the mounting base and the air-tightness test mechanism to descend smoothly to the testing position, effectively replacing the tedious 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 when the air-tightness test mechanism is connected to the oil channel under test, laying the structural foundation for subsequent precise detection of leaks in the oil channel itself.

[0008] 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-maintaining end; the venting end of the sealing cover is connected to the detection end of the airtightness detection mechanism; the pressure-maintaining end of the sealing cover is cylindrical and has a diameter greater than the diameter of the oil passage opening of the transmission housing; One end of the sealing plug is fixed in the sealing cover and seals and separates the inner cavity of the sealing cover, and the other end partially extends out of the sealing cover and is adapted to slide and seal with the inner cavity of the oil passage opening of the transmission case. The sealing ring is movably arranged at the end of the sealing cover away from the detection end of the airtightness detection mechanism, and a first elastic telescopic structure is provided between the sealing ring and the inner wall of the sealing cover for enabling the sealing ring to move along the length direction of the sealing cover; When the sealing cover is arranged on the transmission case oil passage orifice, the sealing plug extends into the transmission case oil passage orifice and seals the transmission case oil passage orifice, and the sealing ring seals the gap between the inner wall of the pressure-maintaining end of the sealing cover and the outer wall of the transmission case oil passage orifice; A pressure-maintaining cavity is defined between the pressure-maintaining end of the sealing cover, the sealing plug, and the sealing ring. A pressure-maintaining cavity is provided in the pressure-maintaining cavity for detecting the air pressure in the pressure-maintaining cavity. An air inlet passage connecting the vent end and the pressure-maintaining cavity, and an air outlet passage connecting the pressure-maintaining cavity and the inner cavity of the oil passage of the transmission housing are respectively provided in the sealing plug. The valve opening structure is located in the sealing plug and opens when the value of the pressure sensor reaches a set value and remains constant.

[0009] By adopting the above-mentioned technical solution, the sealing mechanism is uniquely designed, with a special sealing cover structure. The larger diameter pressure-maintaining end can completely cover the external area of ​​the oil channel nozzle. When the tooling is lowered into place, the sealing plug inserted into the nozzle seals the center hole, while the movable sealing ring, under the action of the first elastic telescopic structure, clings to the outer wall of the nozzle, completely sealing the annular gap between the inner wall of the sealing cover's pressure-maintaining end and the outer wall of the nozzle. This forms a "pressure-maintaining chamber" independent of the interior of the oil channel, enclosed by the sealing cover's pressure-maintaining end, the sealing plug, and the sealing ring. When high-pressure gas is introduced into the vent port through the air-tightness detection mechanism, the gas first fills the pressure-maintaining chamber through the air inlet channel, and the pressure sensor monitors the pressure in the pressure-maintaining chamber in real time. Only after the pressure reaches the set value and stabilizes will the valve opening mechanism be triggered, opening the outlet channel to the interior of the oil channel, thus ensuring that subsequent testing is logically targeted at the oil channel itself.

[0010] Optionally, the valve opening structure includes a sealing column and a second elastic telescopic structure, a mounting groove communicating with the pressure-maintaining chamber is defined in the sealing plug, the mounting groove is communicated with the air outlet channel, and the sealing plug is slidably and sealingly mounted in the mounting groove to seal and separate the pressure-maintaining chamber and the air outlet channel; A sealing channel is provided in the sealing column, one end of the sealing channel passes through the sealing column and is connected to the pressure-maintaining chamber, and the other end passes through the inner wall of the sealing column. The second elastic telescopic structure is provided in the mounting groove and can provide a force for the sealing column to slide into the pressure-maintaining chamber. When the value of the pressure sensor reaches a set value and remains constant, the airtightness detection mechanism gradually pushes the sealing column until the sealing channel connects the pressure-maintaining chamber and the air outlet channel.

[0011] By adopting the above technical solution, the valve opening structure realizes the automatic triggering function through ingenious mechanical design. Under the action of the second elastic telescopic structure, the default position of the sealing column is to separate the installation groove, thereby physically blocking the communication path between the pressure-holding chamber and the air outlet channel. When the pressure in the pressure-holding chamber gradually increases to the set value and remains stable, the air tightness detection mechanism immediately introduces high-pressure gas to overcome the resistance of the second elastic telescopic structure and push the sealing column to slide in the installation groove. Until the sealing channel opened in the sealing column is accurately aligned and connected to the pressure-holding chamber and the air outlet channel, high-pressure gas is allowed to formally enter the inside of the oil channel being tested. The mechanical linkage of this structure is reliable, and it effectively enforces the step-by-step operation process of "first verifying the interface seal, and then detecting oil channel leakage".

[0012] Optionally, the first elastic telescopic structure includes 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 to the inner wall of the pressure-maintaining end, and the other end is fixedly connected to the sealing ring, and the first elastic member is used to provide a force for the sealing ring to move toward the outlet of the pressure-maintaining chamber; The second elastic telescopic structure includes a second telescopic rod and a second elastic member sleeved on the second telescopic rod. The second telescopic rod is located in the mounting groove, and one end of the second telescopic rod 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. The second elastic member is used to provide a force for the sealing column to move out of the mounting groove.

[0013] By adopting this technical solution, the first elastic telescopic structure is specifically guided and bears tension / compression by the first telescopic rod, while the first elastic member continuously provides elastic force to press the sealing ring against the outer wall of the pipe orifice, ensuring that the sealing ring can effectively compensate for microscopic dimensional differences or minor imperfections between different pipe orifices and maintain the reliability of the annular gap seal. The second elastic telescopic structure, similarly guided and supported by the second telescopic rod, relies on the thrust of the second elastic member to maintain the sealing post in its default sealing state. Simultaneously, its reaction force design ensures that the sealing post requires precise external force to move and open the valve, ensuring stable and controllable operation.

[0014] Optionally, the inner wall of the pressure-maintaining end of the sealing cover is inclined, and the wall thickness of the sealing cover gradually increases from the vent end close to the sealing cover to the vent end away from the sealing cover.

[0015] By adopting this technical solution, the inclined inner wall design significantly increases the effective contact area with the movable sealing ring, and can provide guidance and correction for the sealing ring's posture, further improving the stability of the annular gap seal and its ability to accommodate pipe orifice manufacturing tolerances. The gradual increase in wall thickness enhances the structural strength and rigidity of the distal end of the pressure-maintaining cavity, ensuring that it is less likely to deform under high pressure and maintaining the geometric stability of the sealing interface.

[0016] Optionally, a plurality of support blocks are fixed on the inner wall of the pressure-maintaining end of the sealing cover at intervals along the circumferential direction, and each of the support blocks is used to support the end of the oil channel pipe opening of the transmission housing.

[0017] By employing this technical solution, when the sealing cover descends and covers the oil passage opening, the support blocks first contact the end face of the opening, assuming primary load-bearing and precise positioning, thus preventing the sealing ring and plug from being directly subjected to excessive impact or pressure, which could damage them. This not only protects the sealing elements but, more importantly, ensures that the sealing cover remains level and aligned relative to the opening, allowing the sealing ring to be evenly compressed against the outer wall of the opening, achieving a uniform and reliable seal. Furthermore, a gap is reserved between the transmission case's oil passage opening and the inner wall of the pressure-maintaining end for gas flow, maintaining a constant pressure throughout the pressure-maintaining chamber.

[0018] Optionally, the air tightness detection mechanism includes a high-pressure tube and a solenoid valve, and there are multiple high-pressure tubes and solenoid valves respectively. Each high-pressure tube is connected to the ventilation end of the corresponding sealing cover, and each solenoid valve is arranged in the corresponding high-pressure tube, and each high-pressure tube is connected to an external high-pressure air pump.

[0019] By adopting this technical solution, multiple high-pressure pipes are connected to corresponding sealing covers, each with its own solenoid valve installed, and ultimately connected to an external high-pressure air source. This architecture enables the tooling to simultaneously pressurize, maintain pressure, and leak test oil passages at multiple locations on the transmission housing. The independent on-off control of the solenoid valves precisely manages the start of pressurization, the start of the pressure maintenance phase, and possible pressure relief for each oil passage, achieving process independence for multi-point testing and significantly improving testing efficiency.

[0020] The present application also provides a method for detecting the air tightness of the oil channel of a gearbox housing, comprising the following steps: S1: Fix the gearbox housing on the transverse movement mechanism and control the transverse movement mechanism to move the gearbox housing to the bottom of the mounting seat; S2: The lifting mechanism drives the mounting seat to descend until the inner wall of the pressure-maintaining end of the sealing cover abuts against the end of the oil passage opening of the transmission housing; 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; S4: Obtain the value of the pressure sensor. If the value of the pressure sensor remains unchanged within the specified time, continue to turn on the high-pressure air pump to perform an air tightness test on the transmission case oil passage. If the value of the pressure sensor decreases within the specified time, check the connection seal between the pressure-maintaining end of the sealing cover and the end of the transmission case oil passage pipe. Continue the air tightness test until the value of the pressure sensor stops decreasing within the fixed time. S5: Obtain the detection structure of the air tightness detection mechanism and judge the air tightness of the transmission oil channel.

[0021] By employing this method, the testing process is systematically divided into two closely interconnected core stages. First, after the tooling is in place and sealed, the "connection interface sealing verification (S3-S4, first half)" is performed: pressurizing only the pressure-holding chamber to the set value and maintaining the pressure. Pressure sensor data is monitored to determine whether the double seal formed between the sealing plug and the inner wall of the pipe orifice, and between the sealing ring and the outer wall of the pipe orifice, is completely reliable. Only after the pressure remains stable during this stage does the second stage, "oil channel body air tightness testing (S4, second half - S5)," begin: triggering the valve opening mechanism to formally introduce high-pressure gas into the tested oil channel, followed by pressure maintenance and leak testing. This step-by-step approach completely eliminates the interference of connection leakage on oil channel body leakage judgment in traditional methods, ensuring that any detected drop in holding pressure is necessarily due to actual leakage in the oil channel body or its internal interface. This significantly improves the absolute accuracy and reliability of the test results and eliminates misjudgments.

[0022] In summary, this application includes at least one of the following beneficial technical effects: 1. This application successfully pre-positions and automates the verification of the sealing reliability of the connection interface by designing a dedicated integrated chemical equipment and testing method. Specifically, the unique sealing mechanism added to the equipment creates a physically isolated "pre-pressure holding chamber" at the oil channel nozzle. This chamber is then pressurized and pressure-maintained before the test gas is introduced into the oil channel body. This design allows any joint leaks caused by nozzle machining defects, damage, or improper installation of sealing elements to be immediately identified and eliminated before the formal oil channel air tightness test begins. This fundamentally solves the problem of systematic misjudgment caused by traditional plug-type testing methods, which cannot distinguish between joint leaks and oil channel body leaks. This significantly reduces the risk of qualified products being mistakenly rejected, avoids unnecessary rework and scrap, and improves the accuracy and reliability of testing. 2. The sealing mechanism of this invention adopts an innovative dual-channel sealing and mechanical triggering linkage structure. The sealing plug deep inside the oil channel pipe mouth and the elastic sealing ring surrounding the outside of the pipe mouth work together to achieve double insurance sealing of the connection interface, forming an independent and closed front pressure-maintaining chamber. More importantly, before the sealing of the pressure-maintaining chamber itself is verified, the channel leading to the inside of the oil channel is mechanically blocked by the valve opening structure. This mechanical interlocking design mandates that the qualified sealing verification of the pressure-maintaining chamber is the only prerequisite for the next step of testing the oil channel body, ensuring the rigorous execution of the detection logic sequence, completely eliminating the possibility of logical confusion in the detection process caused by human operation errors or instrument misjudgment, and greatly enhancing the automation, standardization and traceability of the detection process; 3. The invention's inspection method and tooling system deeply integrate automated positioning and multi-point parallel inspection capabilities. By integrating a lifting mechanism, a transverse movement mechanism, and independent sealing and inspection channels for multiple oil channel openings, it achieves precise positioning and rapid docking of the gearbox housing on the tooling, as well as simultaneous or independent pressurization, pressure maintenance, and leak monitoring of multiple oil channels. This highly integrated automated system significantly reduces manual intervention steps and positioning time, greatly improving inspection cycle time and overall efficiency. It completely changes the traditional inefficient inspection mode of installing plugs, sealing, and pressurizing one by one, and can adapt to the inspection needs of housings with different specifications and complex oil channel layouts. 4. The air tightness test of this application must be carried out only when there is no leakage in the "front pressure cabin", otherwise the test cannot be carried out, which ensures the accuracy of the test results. The pressure environment of the "front pressure cabin" is the pressure environment during the air tightness test, that is, it is consistent with the environment during the air tightness test. Compared with the method of sealing with a general sealing structure, the sealing structure in this application can simulate the pressure during the air tightness test on the connection, ensuring that the sealing structure can still remain sealed during the air tightness test. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0024] Figure 1 This is a schematic diagram of the overall structure of a gearbox housing oil channel air tightness detection tool in an embodiment of the present application; Figure 2 yes Figure 1 A schematic diagram of the structure of a gearbox housing oil channel air tightness detection tool from the bottom perspective; Figure 3 yes Figure 2 Schematic diagram of the structure at the middle mounting seat; Figure 4 yes Figure 3 Cross-sectional view of the sealing mechanism.

[0025] Figure markings: 1. test bench; 11. mounting seat; 2. lifting mechanism; 3. transverse movement mechanism; 4. air tightness detection mechanism; 5. sealing mechanism; 51. sealing cover; 511. ventilation end; 512. pressure maintaining 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 maintaining chamber; 7. first elastic telescopic structure. DETAILED DESCRIPTION

[0026] The following is combined with Figure 1-4 , further details of this application are given.

[0027] The embodiment of the present application discloses a tool for detecting air tightness of an oil channel of a transmission housing.

[0028] A gearbox housing oil channel air tightness detection tool, refer to Figure 1 and Figure 2 , including a test bench 1, a mounting seat 11 and a lifting mechanism 2 for driving the mounting seat 11 to rise and fall are arranged above the test bench 1, and a transverse movement mechanism 3 for driving the gearbox housing to be transferred to the bottom of the mounting seat 11 is arranged on the surface of the test bench 1 below the mounting seat 11.

[0029] An airtightness detection mechanism 4 for performing airtightness detection on the transmission housing oil channel is provided on the mounting seat 11. A sealing mechanism 5 for sealing the connection between the detection end and the transmission housing oil channel is provided on the detection end of the airtightness detection mechanism 4. The airtightness detection mechanism 4 performs an airtightness test after the sealing mechanism 5 seals the connection.

[0030] This gearbox housing oil channel air-tightness test tool integrates a test bench 1, a mounting base 11, a lifting mechanism 2, a traversing mechanism 3, and an air-tightness test mechanism 4. Operating in an automated, coordinated manner, the traversing 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 air-tightness test mechanism 4, to a smooth lowering position to the test position. This effectively replaces the tedious steps of traditional manual positioning and plug installation, significantly improving the overall efficiency and automation level of the test operation. A built-in sealing mechanism 5 ensures a reliable initial seal when the air-tightness test mechanism 4 is connected to the oil channel under test, laying the structural foundation for subsequent, accurate detection of leaks in the oil channel itself (rather than at the connection).

[0031] The traverse mechanism 3 adopts a linear motor, a fixed seat is fixed on the traverse seat of the linear motor, and the gearbox housing can be fixed on the fixed seat. The lifting mechanism 2 adopts an electric telescopic rod, and the telescopic end of the electric telescopic rod is fixedly connected to the mounting seat 11.

[0032] 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 ventilation end 511 and a pressure maintaining end 512. The ventilation end 511 of the sealing cover 51 is connected to the detection end of the air tightness detection mechanism 4. The pressure maintaining end 512 of the sealing cover 51 is cylindrical and has a diameter larger than the diameter of the oil channel pipe opening of the gearbox housing.

[0033] One end of the sealing plug 52 is fixed in the sealing cover 51 and seals and separates the inner cavity of the sealing cover 51, and the other end partially extends out of the sealing cover 51 and can be adapted for sliding sealing with the inner cavity of the oil channel pipe opening of the transmission housing. 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 telescopic structure 7 is provided between the sealing ring 53 and the inner wall of the sealing cover 51 for making the sealing ring 53 move along the length direction of the sealing cover 51.

[0034] When the sealing cover 51 is placed on the oil passage opening of the transmission case, the sealing plug 52 extends into the oil passage opening of the transmission case and seals the oil passage opening of the transmission case, 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 oil passage opening of the transmission case.

[0035] Reference Figure 3 and Figure 4 A pressure-maintaining chamber 6 is defined between the pressure-maintaining end 512 of the sealing cover 51, the sealing plug 52, and the sealing ring 53. A pressure-maintaining chamber 6 is provided in the pressure-maintaining chamber 6 with a pressure sensor for detecting the air pressure in the pressure-maintaining chamber 6. The sealing plug 52 is provided with an air inlet passage 521 connecting the vent end 511 with the pressure-maintaining chamber 6, and an air outlet passage 522 connecting the pressure-maintaining chamber 6 with the inner cavity of the oil passage of the transmission housing. The valve opening structure 54 is located in the sealing plug 52 and opens when the pressure sensor value reaches a set value and remains constant.

[0036] The sealing mechanism 5 features a unique design, with a special sealing cover 51 and a larger-diameter pressure-maintaining end 512 that completely covers the outer area of ​​the oil passage opening. When the tooling is lowered into position, the sealing plug 52, inserted into the opening, seals the center hole. The movable sealing ring 53, under the action of the first elastic and telescopic structure 7, clings to the outer wall of the opening, completely sealing the annular gap between the inner wall of the pressure-maintaining end 512 of the sealing cover 51 and the outer wall of the opening. This creates a "pressure-maintaining chamber 6" independent of the interior of the oil passage, enclosed by the pressure-maintaining end 512 of the sealing cover 51, the sealing plug 52, and the sealing ring 53.

[0037] When high-pressure gas is introduced into the vent port 511 via the airtightness detection mechanism 4, the gas first fills the pressure-maintaining chamber 6 via the air inlet passage 521. The pressure sensor then monitors the pressure in the pressure-maintaining chamber 6 in real time. Only after the pressure reaches the set value and stabilizes will the valve opening mechanism 54 be triggered, opening the air outlet passage 522 to the interior of the oil channel. This logically ensures that subsequent testing targets the oil channel itself.

[0038] Reference Figure 3 and Figure 4 The valve opening structure 54 includes a sealing column 541 and a second elastic telescopic structure 542. A mounting groove communicating with the pressure-maintaining chamber 6 is provided in the sealing plug 52. The mounting groove is communicated with the gas outlet channel 522. The sealing plug 52 is slidingly and sealingly installed in the mounting groove and seals and separates the pressure-maintaining chamber 6 and the gas outlet channel 522. A sealing channel 5411 is provided in the sealing column 541, one end of the sealing channel 5411 passes through the sealing column 541 and is connected to the pressure-maintaining chamber 6, and the other end passes through the inner wall of the sealing column 541. The second elastic telescopic structure 542 is arranged in the mounting groove and can provide the sealing column 541 with a force to slide into the pressure-maintaining 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-maintaining chamber 6 and the air outlet channel 522.

[0039] The valve opening structure 54 realizes the automatic triggering function through a clever mechanical design. Under the action of the second elastic telescopic structure 542, the default position of the sealing column 541 is to block the installation groove, thereby physically blocking the communication path between the pressure-maintaining chamber 6 and the air outlet channel 522. When the pressure in the pressure-maintaining chamber 6 gradually increases to the set value and remains stable, the airtightness detection mechanism 4 immediately introduces high-pressure gas, overcomes the resistance of the second elastic telescopic structure 542, and pushes the sealing column 541 to slide in the installation groove. Until the sealing channel 5411 opened in the sealing column 541 is accurately aligned and connected to the pressure-maintaining chamber 6 and the air outlet channel 522, the high-pressure gas is allowed to formally enter the inside of the oil channel being tested. The mechanical linkage of this structure is reliable, and effectively enforces the step-by-step operation process of "first verifying the interface seal, and then detecting oil channel leakage".

[0040] Reference Figure 3 and Figure 4 The first elastic telescopic structure 7 includes 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 to the inner wall of the pressure-maintaining end 512, and the other end is fixedly connected to the sealing ring 53. The first elastic member is used to provide a force for the sealing ring 53 to move toward the outlet of the pressure-maintaining chamber 6.

[0041] Reference Figure 3 and Figure 4 The second elastic telescopic structure 542 includes a second telescopic rod and a second elastic member mounted 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 member is used to provide a force for the sealing column 541 to move out of the mounting groove.

[0042] The first elastic telescopic structure 7 is specifically guided by the first telescopic rod and bears tension / compression. The first elastic member continuously provides elastic force to press the sealing ring 53 against the outer wall of the pipe orifice, ensuring that the sealing ring 53 can effectively compensate for microscopic dimensional differences or minor imperfections between different pipe orifices 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. The thrust of the second elastic member maintains the sealing post 541 in the default sealing state. At the same time, its reaction force design ensures that the sealing post 541 requires precise external force to move to open the valve, ensuring stable and controllable operation.

[0043] The inner wall of the pressure-maintaining end 512 of the sealing cover 51 is inclined, and the wall thickness of the sealing cover 51 gradually increases from the vent end 511 closest to the sealing cover 51 to the vent end 511 farther away from the sealing cover 51. This inclined inner wall design significantly increases the effective contact area with the movable sealing ring 53 and provides guidance and correction for the seal ring 53, further enhancing the stability of the annular gap seal and its ability to accommodate manufacturing tolerances of the pipe orifice. The gradual increase in wall thickness enhances the structural strength and rigidity of the distal end of the pressure-maintaining chamber 6, ensuring that it is less susceptible to deformation under high pressure and maintaining the geometric stability of the sealing interface.

[0044] A plurality of support blocks 513 are fixed at circumferential intervals on the inner wall of the pressure-maintaining end 512 of the sealing cover 51. Each support block 513 is used to support the end of the transmission case oil passage nozzle. When the sealing cover 51 descends and covers the oil passage nozzle, these support blocks 513 first contact the end face of the nozzle, taking on the primary load-bearing and precise positioning functions, preventing the sealing ring 53 and the sealing plug 52 from being directly subjected to excessive impact or pressure and being damaged. This not only protects the sealing element, but more importantly, ensures that the relative position of the sealing cover 51 and the nozzle remains horizontal and aligned, allowing the sealing ring 53 to be evenly compressed on the outer wall of the nozzle, achieving a uniform and reliable seal. A gap is also reserved between the transmission case oil passage nozzle and the inner wall of the pressure-maintaining end 512 for gas to pass through, ensuring that the air pressure at all locations within the pressure-maintaining chamber 6 is constant.

[0045] The airtightness detection mechanism 4 includes a high-pressure tube and a solenoid valve. There are multiple high-pressure tubes and solenoid valves. Each high-pressure tube is connected to the ventilation end 511 of the corresponding sealing cover 51. Each solenoid valve is set in the corresponding high-pressure tube, and each high-pressure tube is connected to an external high-pressure air pump.

[0046] Multiple high-pressure pipes are connected to corresponding sealing covers 51, each equipped with an independent solenoid valve, and ultimately connected to an external high-pressure air source. This architecture enables the tooling to simultaneously pressurize, maintain pressure, and leak test oil passages at multiple locations on the transmission housing. The independent on-off control of the solenoid valves precisely manages the start of pressurization, the start of the pressure maintenance phase, and possible pressure relief for each oil passage, achieving process independence for multi-point testing and significantly improving testing efficiency.

[0047] The working principle of the gearbox housing oil channel air tightness test tool of the present application embodiment is as follows: the gearbox housing to be tested is accurately positioned by the traverse mechanism 3 to be directly below the mounting seat 11, and then the lifting mechanism 2 drives the mounting seat 11 to descend as a whole, driving the pressure-maintaining end 512 of the sealing cover 51 to completely cover the oil channel pipe opening; At this moment, the sealing plug 52 disposed in the sealing cover 51 is pressed into the inner cavity of the oil passage pipe orifice 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 orifice and the inner wall of the pressure-retaining end 512 to form an outer ring seal. The two work together to physically construct an independent and closed pre-pressure retaining chamber 6 between the sealing plug 52, the pressure-retaining end 512 and the sealing ring 53; At this time, the air tightness detection mechanism 4 introduces high-pressure gas into the pressure-maintaining chamber 6 through the high-pressure pipe, and the pressure sensor monitors the air pressure in the chamber in real time. If the pressure remains stable during the pressure-maintaining stage, it can be verified that the connection interface between the tooling and the oil channel pipe opening is sealed reliably and leak-free. This verification result serves as a necessary condition for triggering the next test: when the pressure in the pressure-maintaining chamber 6 reaches the set value and stabilizes, the airtightness detection mechanism 4 activates the external drive device, exerting an axial thrust on the valve-opening structure 54, overcoming the resistance of the second elastic telescopic structure 542 and pushing the sealing column 541 to precisely move within the installation groove until its internal sealing channel 5411 connects the pressure-maintaining chamber 6 with the previously physically isolated gas outlet channel 522. At this point, high-pressure gas enters the transmission oil channel for the first time. The system then monitors pressure changes within the oil channel using a conventional pressure-maintaining method. Because leakage interference from the connection interface has been completely eliminated in the preceding stages, any pressure drop can be attributed to genuine defects in the oil channel itself or its internal joints. The entire process relies on a parallel air system controlled by the lifting mechanism 2, the lateral movement mechanism 3, and multiple independent solenoid valves to achieve automatic positioning of the housing and simultaneous detection of multiple oil channels. The support block 513 structure provides a contact reference and protection. Ultimately, through phased verification and a mechanical interlock trigger mechanism, it is ensured that the test results only reflect the true airtightness status of the oil channel itself.

[0048] The present application also discloses a method for detecting the air tightness of an oil passage of a transmission housing, comprising the following steps: S1: The gearbox housing is fixedly mounted on the transverse movement mechanism 3, and the transverse movement mechanism 3 is controlled to move the gearbox housing to the position directly below the mounting 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 opening of the transmission housing; 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; S4: Obtain the value of the pressure sensor. If the value of the pressure sensor remains unchanged within the specified time, continue to turn on the high-pressure air pump to perform an airtightness test on the transmission case oil passage. If the value of the pressure sensor decreases within the specified time, check the tightness of the connection between the pressure-maintaining end 512 of the sealing cover 51 and the end of the transmission case oil passage pipe opening. Continue the airtightness test until the value of the pressure sensor stops decreasing within the specified time. S5: Obtain the detection structure of the airtightness detection mechanism 4 and judge the airtightness of the transmission oil channel.

[0049] Unless otherwise defined, the technical or scientific terms used in this application shall have the usual meanings understood by persons of ordinary skill in the field to which this application belongs. The words “first”, “second”, “third” and similar terms used in the specification and claims of this application do not indicate any order, quantity or importance, but are only used to distinguish different components. Words such as “a” or “an” and the like do not indicate a quantity limitation, but rather indicate the existence of at least one. Words such as “include” or “comprise” and the like mean that the elements or objects appearing before “include” or “comprises” cover the elements or objects listed after “include” or “comprises” and their equivalents, and do not exclude other elements or objects. “Up”, “down”, “left”, “right” and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0050] The above are all optional embodiments of the present application, and are not intended to limit the scope of protection of the present application. Therefore, any equivalent changes made based on the structure, shape, and principle of the present application should be included in the scope of protection of the present application.

Claims

1. A gearbox housing oil channel air tightness detection tool, characterized by: The invention comprises a test bench (1), wherein a mounting seat (11) and a lifting mechanism (2) for driving the mounting seat (11) to move up and down are provided above the test bench (1), and a transverse movement mechanism (3) for driving a gearbox housing to move to directly below the mounting seat (11) is provided on the surface of the test bench (1) below the mounting seat (11); The mounting seat (11) is provided with an airtightness detection mechanism (4) for performing airtightness detection on the transmission case oil passage; a sealing mechanism (5) for sealing the connection between the detection end and the transmission case oil passage is provided on the detection end of the airtightness detection mechanism (4); the airtightness detection mechanism (4) performs airtightness detection after the sealing mechanism (5) seals the connection.

2. The gearbox housing oil channel air tightness detection tool according to claim 1, characterized in that: The sealing mechanism (5) comprises a sealing cover (51), a sealing plug (52), a sealing ring (53) and a valve opening structure (54); the sealing cover (51) comprises a venting end (511) and a pressure-maintaining end (512); the venting end (511) of the sealing cover (51) is connected to the detection end of the airtightness detection mechanism (4); the pressure-maintaining end (512) of the sealing cover (51) is cylindrical and has a diameter greater than the diameter of the oil passage opening of the transmission housing; One end of the sealing plug (52) is fixed in the sealing cover (51) and seals and separates the inner cavity of the sealing cover (51); the other end partially extends out of the sealing cover (51) and is adapted to slide and seal with the inner cavity of the oil passage of the transmission housing; the sealing ring (53) is movably arranged 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) for enabling the sealing ring (53) to move along the length direction of the sealing cover (51); When the sealing cover (51) is placed on the transmission case oil passage opening, the sealing plug (52) extends into the transmission case oil passage opening and seals the transmission case oil passage opening, 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 transmission case oil passage opening; A pressure-maintaining cavity (6) is enclosed between the pressure-maintaining end (512) of the sealing cover (51), the sealing plug (52) and the sealing ring (53); a pressure sensor for detecting the air pressure in the pressure-maintaining cavity (6) is provided in the pressure-maintaining cavity (6); an air inlet channel (521) for connecting the vent end (511) and the pressure-maintaining cavity (6) and an air outlet channel (522) for connecting the pressure-maintaining cavity (6) and the inner cavity of the oil passage of the transmission housing are respectively provided in the sealing plug (52); the valve opening structure (54) is located in the sealing plug (52) and opens when the value of the pressure sensor reaches a set value and remains constant.

3. The gearbox housing oil channel air tightness detection tool according to claim 2, characterized in that: The valve opening structure (54) includes a sealing column (541) and a second elastic telescopic structure (542); a mounting groove communicating with the pressure-maintaining chamber (6) is provided in the sealing plug (52); the mounting groove is communicated with the air outlet channel (522); the sealing plug (52) is slidingly and sealingly mounted in the mounting groove and seals and separates the pressure-maintaining chamber (6) and the air outlet channel (522); A sealing channel (5411) is provided in the sealing column (541), one end of the sealing channel (5411) passes through the sealing column (541) and is connected to the pressure-maintaining chamber (6), and the other end passes through the inner wall of the sealing column (541). The second elastic telescopic structure (542) is arranged in the mounting groove and can provide the sealing column (541) with a force to slide into the pressure-maintaining chamber (6). When the value of the pressure sensor reaches a set value and remains constant, the airtightness detection mechanism (4) gradually pushes the sealing column (541) until the sealing channel (5411) connects the pressure-maintaining chamber (6) and the air outlet channel (522).

4. The gearbox housing oil channel air tightness detection tool according to claim 3, 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 to the inner wall of the pressure-maintaining end (512), and the other end is fixedly connected to the sealing ring (53), and the first elastic member is used to provide the sealing ring (53) with a force to move toward the outlet of the pressure-maintaining chamber (6); The second elastic telescopic structure (542) includes 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 of the second telescopic rod is fixedly connected to the inner wall of the installation groove, and the other end is fixedly connected to the end of the sealing column (541). The second elastic member is used to provide the sealing column (541) with a force to move out of the installation groove.

5. The gearbox housing oil channel air tightness detection tool according to claim 2, 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 direction close to the vent end (511) of the sealing cover (51) to the direction away from the vent end (511) of the sealing cover (51).

6. The gearbox housing oil channel air tightness detection tool according to claim 2, characterized in that: A plurality of support blocks (513) are fixed on the inner wall of the pressure-maintaining end (512) of the sealing cover (51) at intervals along the circumferential direction, and each support block (513) is used to support the end of the oil channel pipe opening of the transmission housing.

7. The gearbox housing oil channel air tightness detection tool according to claim 2, characterized in that: The airtightness detection mechanism (4) includes a high-pressure pipe and a solenoid valve. A plurality of the high-pressure pipes and the solenoid valves are provided correspondingly. Each high-pressure pipe is communicated with the ventilation end (511) of the corresponding sealing cover (51). Each solenoid valve is provided in the corresponding high-pressure pipe. Each high-pressure pipe is communicated with an external high-pressure air pump.

8. A method for testing the air tightness of a transmission case oil passage, using a transmission case oil passage air tightness testing tool as claimed in any one of claims 1 to 7, comprising the following steps: S1: The gearbox housing is fixedly mounted on the transverse movement mechanism (3), and the transverse movement mechanism (3) is controlled to drive the gearbox housing to move to the position directly below the mounting 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 of the transmission housing; 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; S4: Obtain the value of the pressure sensor. If the value of the pressure sensor remains unchanged within the specified time, continue to turn on the high-pressure air pump to perform an air tightness test on the oil passage of the transmission housing. If the value of the pressure sensor decreases within the specified time, check the connection sealing between the pressure-maintaining end (512) of the sealing cover (51) and the end of the oil passage of the transmission housing. Continue to perform the air tightness test until the value of the pressure sensor no longer decreases within the fixed time. S5: Obtain the detection structure of the air tightness detection mechanism (4) and judge the air tightness of the transmission oil channel.

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