A method for preventing air leakage of a central air charging and discharging bridge housing

Abstract

The application discloses a kind of central air charging bridge housing leak-proof processing method;Including the following steps: S1, first half shaft sleeve is cleaned;S2, using thermal expansion and contraction is processed;S3, in the shaft sleeve press-in part smears spot welding sealant, increase the sealing performance of bridge housing after cooling;S4, bridge housing is cooled to room temperature after pressing, then welds anti-twist hole, prevents hot deformation leakage;S5, directly to bridge housing and shaft sleeve by pressure drop method air tightness detection;The application is processed by thermal expansion and contraction to bridge housing and shaft sleeve, and is sealed by spot welding sealant to bridge housing and shaft sleeve Connection, by induction ring heating treatment, so that spot welding sealant is sealed and connected, improve the sealing connection of bridge housing and shaft sleeve, and re-weld anti-twist hole, prevent hot deformation leakage, by pressure drop method test, there is slight leakage extreme phenomenon, after review repair, in the bridge housing air passage is solved by the way of filling and plugging with glue Leak problem.

Description

Technical Field

[0001] This invention belongs to the field of bridge housing processing technology, specifically relating to a leak-proof processing method for a central inflation / deflation bridge housing. Background Technology

[0002] The separable axle housing consists of left and right axle housings and axle bushings. After the left and right axle housings are cast, axle bushings are pressed into the outer end of each housing. Then, bolts arranged circumferentially along the mating surface are tightened together to form the separable axle housing. This type of axle housing has a simple structure, good manufacturability, and good support rigidity for the main reducer. Furthermore, during installation, the axle housing connections are sealed with adhesive to improve connection strength and sealing.

[0003] Current technology involves rapidly expanding the axle housing body through induction heating to press the axle sleeve into it, followed by welding anti-torsion holes at high temperatures. After processing, an airtightness test is conducted to detect leaks. The axle sleeve and axle housing are press-fitted with an interference fit, and the induction heating must provide sufficient expansion for the sleeve to be pressed into the axle housing. However, various axle housing processing methods on the market still have various problems.

[0004] For example, the processing method of automobile bearing axle housing disclosed in the authorization announcement number CN101524736B achieves the combined use of hot shrinking and cold pushing technology to directly shrink and push the shaft head on the round tube; firstly, the bearing platform and oil seal platform of the shaft head are thickened by using a shrinking forming mold to improve the strength of the area, and then the round tube is pushed into a square tube by cold pushing to form the shaft head. This process replaces the existing welding method for the shaft head and shaft tube, avoiding low welding strength, welding deformation, and welding spatter. It also solves the problem that the fatigue strength of the weld between the shaft head and shaft tube is lower than that of the base material, and that fatigue damage easily occurs in the heat-affected zone. However, it does not solve the problem of uneven wall thickness (14mm at the thinnest and 69mm at the thickest) in the heated part of the axle housing. Under high-power heating, this leads to uneven expansion of the inner hole (0.6-0.8mm expansion in thin-walled areas and 0.2-0.3mm expansion in thick-walled areas). During the cooling process after the sleeve is pressed in, uneven shrinkage causes gaps. Furthermore, immediately welding the anti-torsion hole in the next process further enlarges the gaps, leading to air leakage during the airtightness test. In addition, in order to heat and expand the thick-walled areas of the axle housing, the heating temperature in the thin-walled areas exceeds 500°C. As the pearlite content increases, it damages the mechanical properties of the axle housing material, posing a serious hidden danger and failing to meet design and usage requirements. Therefore, we propose a leak-proof processing method for a centrally filled and deflated axle housing. Summary of the Invention

[0005] The purpose of this invention is to provide a leak-proof processing method for a central inflation / deflation air bridge housing, so as to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a method for preventing air leakage in a central inflation / deflation air bridge housing, comprising the following steps: S1. First, clean the half-shaft sleeve: clean the connection between the bushing and the axle housing with a brush, then clean the connection between the bushing and the axle housing with alcohol, and then clean the connection between the bushing and the axle housing with distilled water. S2. Processing with thermal expansion and contraction: Based on the expansion coefficient and structure of the bridge housing material, the heating power and heating time parameters of the induction coil are set to make the heated parts of the bridge housing expand evenly. Based on the expansion coefficient and structure of the bushing material, the cooling and cooling time parameters are set to make the cooled parts of the bushing contract evenly. S3. Apply spot welding sealant to the bushing pressing part to increase the sealing performance of the axle housing after cooling: Before pressing the bushing into the axle housing, apply spot welding sealant to the bushing pressing part, then press the bushing into the connection of the axle housing, and then allow it to cool and warm up naturally. S4. After the bridge housing is press-fitted, it is cooled to room temperature and then anti-torsion holes are welded to prevent thermal deformation and air leakage. The bridge housing is cooled down by natural placement and the bushing is warmed up, so that the bridge housing and bushing can be kept at room temperature. Then, the bridge housing and bushing are heated by induction coil and the spot welded sealant is used to seal the connection between the bridge housing and bushing. S5. The air tightness of the axle housing and bushing is directly tested by the pressure drop method: The pressure drop test showed that there was a slight leakage. After review and repair, the leakage problem was solved by filling the air passage in the axle housing with glue.

[0007] Preferably, in S2, the heating power of the induction coil is set to 6-8KW, the heating time is set to 180s, the heat preservation power is set to 2-3KW, and the heat preservation time is set to 96s.

[0008] Preferably, the two ends of the bridge housing in S2 are slowly heated to 300°C-350°C to ensure uniform expansion of the heated parts. The pressure holding and cooling time after press fitting is set to 120s to ensure that the bridge housing and half-shaft sleeve shrink sufficiently during cooling.

[0009] Preferably, the bushing in S2 is frozen with liquid nitrogen, which causes the connection of the bushing to shrink, making it easier to press the bushing and the bridge housing into place. After freezing, the temperature of the bushing is controlled between -50°C and 20°C.

[0010] Preferably, in step S4, after the press-fitted bridge housing and bushing are cooled to room temperature, a gas shielded welding process is performed to prevent twisting holes. The welding current and voltage are stable, the welding temperature is well controlled, and the gas shielded welding voltage is controlled at 20-25V, the current at 200-250A, and the gas flow rate at 15-25L / min.

[0011] Preferably, before press-fitting the axle housing and bushing, the mating parts between the inner hole of the axle housing and the outer circle of the half-shaft sleeve should be cleaned, and there should be no iron filings, oil stains, or sharp corners. Then, the spot welding sealant should be evenly applied to the outer circle surface of the half-shaft sleeve.

[0012] Preferably, in the pressure drop method in S5, pressurized gas is introduced into the sealed cavity of the bridge housing and bushing, and at the same time, gas of the same pressure is introduced into a standard tank. After standing still for a period of time, the pressure in the standard tank and the workpiece are observed.

[0013] Preferably, the small pressure difference generated on the differential pressure sensor due to leakage between the bridge housing and the bushing is quantitatively calculated by the leak detector based on the output change of the differential pressure sensor to determine the leakage amount of the tested object. The presence of a reference object minimizes the impact of differences in the external environment and the working process itself on the test.

[0014] Preferably, in the extreme case of slight air leakage caused by weld quality issues in the axle housing and bushing, the air leakage problem is solved by filling with adhesive, that is, applying thread sealant to the leaking area of ​​the axle housing and bushing, and performing the operation by three filling and three drying cycles.

[0015] Preferably, the air passage of the bridge housing is filled with thread sealant, then dried for one hour, and then the above operation is repeated twice. Then, the pressure is maintained at 0.8MPa for 10 minutes, and then the residual sealant in the air passage is cleaned. The passage is left to stand for 4 hours to allow the sealant to completely penetrate into the gap and block the air leakage.

[0016] Compared with the prior art, the beneficial effects of the present invention are: In use, this invention utilizes thermal expansion and contraction to process the axle housing and bushing. During processing, the axle housing and bushing are cleaned to improve their cleanliness, facilitating pressing. During pressing, spot welding sealant is applied to the bushing to ensure a tight seal between the axle housing and bushing. Finally, heating with an induction coil further solidifies the sealant, enhancing the overall sealing. Anti-torsion holes are then welded to prevent thermal deformation and leakage. Pressure drop testing revealed a slight leakage, which was subsequently reviewed and repaired. The leakage was resolved by filling the air passages in the axle housing with adhesive. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the steps of the present invention. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] Please see Figure 1 This invention provides a technical solution: a method for preventing air leakage in a central inflation / deflation air bridge housing, comprising the following steps: S1. First, clean the half-shaft sleeve: clean the connection between the bushing and the axle housing with a brush, then clean the connection between the bushing and the axle housing with alcohol, and then clean the connection between the bushing and the axle housing with distilled water. S2. Processing with thermal expansion and contraction: Based on the expansion coefficient and structure of the bridge housing material, the heating power and heating time parameters of the induction coil are set to make the heated parts of the bridge housing expand evenly. Based on the expansion coefficient and structure of the bushing material, the cooling and cooling time parameters are set to make the cooled parts of the bushing contract evenly. S3. Apply spot welding sealant to the bushing pressing part to increase the sealing performance of the axle housing after cooling: Before pressing the bushing into the axle housing, apply spot welding sealant to the bushing pressing part, then press the bushing into the connection of the axle housing, and then allow it to cool and warm up naturally. S4. After the bridge housing is press-fitted, it is cooled to room temperature and then anti-torsion holes are welded to prevent thermal deformation and air leakage. The bridge housing is cooled down by natural placement and the bushing is warmed up, so that the bridge housing and bushing can be kept at room temperature. Then, the bridge housing and bushing are heated by induction coil and the spot welded sealant is used to seal the connection between the bridge housing and bushing. S5. The air tightness of the axle housing and bushing is directly tested by the pressure drop method: The pressure drop test showed that there was a slight leakage. After review and repair, the leakage problem was solved by filling the air passage in the axle housing with glue.

[0020] In order to heat the bridge housing, maintain its expansion, and ensure uniform expansion, in this embodiment, preferably, the heating power of the induction coil in S2 is set to 6-8KW, the heating time is set to 180s, the heat preservation power is set to 2-3KW, and the heat preservation time is set to 96s.

[0021] In order to ensure that the bridge housing expands uniformly and prevent damage to the bridge housing at high temperatures, in this embodiment, preferably, the two ends of the bridge housing in S2 are slowly heated to 300°C-350°C to ensure that the heated parts expand uniformly. The pressure holding and cooling time after pressing is set to 120s to ensure that the bridge housing and the half-shaft sleeve shrink sufficiently during cooling.

[0022] In order to achieve the freezing treatment of the bushing, so as to facilitate the processing of the bushing and the press-fit connection between the bushing and the axle housing, in this embodiment, preferably, the bushing in S2 is frozen with liquid nitrogen, so that the connection of the bushing shrinks, which facilitates the press-fit connection between the bushing and the axle housing, and the temperature of the bushing after freezing is controlled at -50°C to -20°C.

[0023] In order to achieve gas shielded welding of the axle housing and bushing, so as to facilitate the welded connection of the axle housing and bushing and improve the sealing performance, in this embodiment, preferably, after the axle housing and bushing are press-fitted and cooled to room temperature in S4, gas shielded welding is used to perform the anti-torsion hole welding process. The welding current and voltage are stable, the welding temperature is well controlled, and the gas shielded welding voltage is controlled at 20-25V, the current at 200-250A, and the gas flow rate at 15-25L / min.

[0024] In order to achieve a stable connection between the axle housing and the bushing, facilitate sealing welding, and improve fit, in this embodiment, preferably, the mating parts between the inner hole of the axle housing and the outer circle of the half-shaft sleeve are cleaned before the axle housing and bushing are press-fitted, and there should be no iron filings, oil stains, or sharp corners. Then, spot welding sealant is evenly applied to the outer circle surface of the half-shaft sleeve.

[0025] In order to perform a sealing test on the bridge housing and bushing, in this embodiment, preferably, the pressure drop method in S5 involves introducing pressurized gas into the sealed cavity of the bridge housing and bushing, and simultaneously introducing gas of the same pressure into a standard tank, allowing it to stand for a period of time, and then observing the pressure in the standard tank and the workpiece.

[0026] In order to achieve air pressure detection of the axle housing and bushing, that is, to process and detect the air pressure difference, in this embodiment, preferably, the small pressure difference generated on the differential pressure sensor due to leakage of the axle housing and bushing is quantitatively calculated by the leak detector based on the output change of the differential pressure sensor. The presence of the reference object minimizes the influence of external environment and the working condition itself on the test.

[0027] In order to effectively apply thread sealant and improve the connection and sealing between the axle housing and the bushing, in this embodiment, preferably, in the extreme case of slight air leakage caused by weld quality in the axle housing and bushing, the air leakage problem is solved by filling with sealant, that is, applying thread sealant to the leaking area of ​​the axle housing and bushing, and performing the operation by three filling and three drying.

[0028] In order to improve the sealing performance by performing a sealing test after applying thread sealant, in this embodiment, preferably, thread sealant is injected into the air passage of the bridge housing, then dried for one hour, and then the above operation is repeated twice. Then, the pressure is maintained at 0.8MPa for 10 minutes, and then the residual sealant in the air passage is cleaned out. After standing for 4 hours, the sealant is allowed to completely penetrate into the gap and block the air leakage.

[0029] Working principle and usage process of this invention: First, clean the axle bushing: clean the connection between the bushing and the axle housing with a brush, then clean the connection between the bushing and the axle housing with alcohol, and then clean the connection between the bushing and the axle housing with distilled water. The second step is to process the material using thermal expansion and contraction: Based on the expansion coefficient and structure of the bridge housing material, the heating power and heating time parameters of the induction coil are set to make the heated parts of the bridge housing expand evenly. Based on the expansion coefficient and structure of the bushing material, the cooling and cooling time parameters are set to make the cooled parts of the bushing contract evenly. The third step is to apply spot welding sealant to the press-in part of the bushing to increase the sealing performance of the axle housing after cooling: Before pressing the bushing into the axle housing, apply spot welding sealant to the press-in part of the bushing, then press the bushing into the connection of the axle housing, and then allow it to cool and warm up naturally. Step 4: After the bridge housing is press-fitted, it is cooled to room temperature and then anti-torsion holes are welded to prevent thermal deformation and air leakage. The bridge housing is cooled down by natural placement and the bushing is warmed up so that the bridge housing and bushing can be kept at room temperature. Then, the bridge housing and bushing are heated by induction coil and the spot welded sealant is used to seal the connection between the bridge housing and bushing. Step 5: Directly test the air tightness of the axle housing and bushing using the pressure drop method: The pressure drop test showed a slight leakage. After review and repair, the leakage problem was solved by filling the air passage in the axle housing with glue.

[0030] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for preventing air leakage in a central inflation / deflation air bridge housing, characterized in that, It includes the following steps: S1. First, clean the half-shaft sleeve: clean the connection between the bushing and the axle housing with a brush, then clean the connection between the bushing and the axle housing with alcohol, and then clean the connection between the bushing and the axle housing with distilled water. S2. Processing with thermal expansion and contraction: Based on the expansion coefficient and structure of the bridge housing material, the heating power and heating time parameters of the induction coil are set to make the heated parts of the bridge housing expand evenly. Based on the expansion coefficient and structure of the bushing material, the cooling and cooling time parameters are set to make the cooled parts of the bushing contract evenly. S3. Apply spot welding sealant to the bushing pressing part to increase the sealing performance of the axle housing after cooling: Before pressing the bushing into the axle housing, apply spot welding sealant to the bushing pressing part, then press the bushing into the connection of the axle housing, and then allow it to cool and warm up naturally. S4. After the bridge housing is press-fitted, it is cooled to room temperature and then anti-torsion holes are welded to prevent thermal deformation and air leakage. The bridge housing is cooled down by natural placement and the bushing is warmed up, so that the bridge housing and bushing can be kept at room temperature. Then, the bridge housing and bushing are heated by induction coil and the spot welded sealant is used to seal the connection between the bridge housing and bushing. S5. The air tightness of the axle housing and bushing is directly tested by the pressure drop method: The pressure drop test showed that there was a slight leakage. After review and repair, the leakage problem was solved by filling the air passage in the axle housing with glue.

2. The leak-proof processing method for a central inflation / deflation air bridge housing according to claim 1, characterized in that: The heating power of the induction coil in S2 is set to 6-8KW, the heating time is set to 180s, the heat preservation power is set to 2-3KW, and the heat preservation time is set to 96s.

3. The leak-proof processing method for a central inflation / deflation air bridge housing according to claim 1, characterized in that: The bridge housing in S2 is slowly heated to 300°C-350°C at both ends to ensure uniform expansion of the heated parts. After pressing, the pressure holding and cooling time is set to 120s to ensure that the bridge housing and half-shaft sleeve shrink sufficiently during cooling.

4. The leak-proof processing method for a central inflation / deflation air bridge housing according to claim 1, characterized in that: The bushing in S2 is frozen with liquid nitrogen, which causes the connection of the bushing to shrink, making it easier to press the bushing and the bridge housing into place. After freezing, the temperature of the bushing is controlled between -50°C and 20°C.

5. The leak-proof processing method for a central inflation / deflation air bridge housing according to claim 1, characterized in that: After the bridge housing and bushing in S4 are press-fitted and cooled to room temperature, they are welded with gas shielded welding to prevent twisting holes. The welding current and voltage are stable, the welding temperature is well controlled, and the gas shielded welding voltage is controlled at 20-25V, the current at 200-250A, and the gas flow rate at 15-25L / min.

6. The leak-proof processing method for a central inflation / deflation air bridge housing according to claim 1, characterized in that: Before press-fitting the axle housing and bushing, clean the mating parts between the inner hole of the axle housing and the outer circle of the half-shaft sleeve. There should be no iron filings, oil stains, or sharp edges. Then, apply spot welding sealant evenly to the outer circle surface of the half-shaft sleeve.

7. The leak-proof processing method for a central inflation / deflation air bridge housing according to claim 1, characterized in that: The pressure drop method in S5 involves introducing pressurized gas into the sealed cavity of the bridge housing and bushing, while simultaneously introducing the same pressure into a standard tank. After a period of time, the pressure inside the standard tank and the workpiece are observed.

8. A method for preventing air leakage in a central inflation / deflation air bridge housing according to claim 7, characterized in that: The small pressure difference generated on the differential pressure sensor due to leakage between the bridge housing and bushing is quantitatively calculated by the leak detector based on the output change of the differential pressure sensor. The presence of the reference object minimizes the impact of differences in the external environment and the working process itself on the test.

9. A method for preventing air leakage in a central inflation / deflation air bridge housing according to claim 1, characterized in that: The bridge housing and bushing experienced a minor air leakage due to weld quality issues. The leakage was resolved by applying sealant to the leaking areas of the bridge housing and bushing, using a three-stage sealing process.

10. A method for preventing air leakage in a central inflation / deflation air bridge housing according to claim 9, characterized in that: The air passage of the bridge housing is filled with thread sealant, then dried for one hour. The above operation is repeated twice. Then, the pressure is maintained at 0.8 MPa for 10 minutes. After that, the residual sealant in the air passage is cleaned and left to stand for 4 hours to allow the sealant to completely penetrate into the gap and seal the air leak.

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