Integrated differential welding exhaust plugging structure and assembly method thereof

Abstract

The application relates to the manufacturing technical field of automobile driving axle differentials, in particular to an integrated differential welding exhaust plugging structure and an assembling method thereof. The exhaust plugging structure comprises a whole differential housing, a main speed reducer driven gear, a positioning pin hole and an exhaust mechanism for exhausting waste gas in a welding ring cavity. The exhaust mechanism is arranged in the differential housing and comprises a gas ring plate communicated with the welding ring cavity, a driving component for driving the gas ring plate, an air inlet pipe cavity and an exhaust pipe cavity arranged in the differential housing, and the air inlet pipe cavity and the exhaust pipe cavity are both communicated between the gas ring plate and the positioning pin hole. The welding exhaust passage and the assembling pin hole of the differential are designed in an integrated mode, the pin used during differential assembling is used to simultaneously realize plugging of the exhaust passage and positioning of internal parts, thereby cancelling independent exhaust holes and subsequent special plugging processes.

Description

Technical Field

[0001] This invention relates to the field of automotive drive axle differential manufacturing technology, specifically to an integrated differential welded exhaust sealing structure and its assembly method. Background Technology

[0002] Welded differentials are becoming a key direction for upgrading automotive transmission systems due to their advantages of lightweight, low cost and high performance. Despite the technical challenges, their market prospects are broad as the penetration rate of new energy vehicles increases and welding technology iterates. Companies need to focus on R&D investment, process optimization and supply chain cooperation to seize the opportunity.

[0003] In the automotive drive axle assembly, the integral differential housing and the driven gear of the main reducer are fixedly connected as one piece by welding. The mating surface of the two forms a semi-closed welding chamber. During the welding process, the air in the chamber expands due to heat, and the high-temperature fumes generated during welding cannot be discharged in time, which can easily lead to defects such as porosity, lack of fusion and shrinkage cavities in the weld, which seriously reduces the strength and sealing of the welded joint. Therefore, in the existing technology, it is generally necessary to set a special vent hole on the welded structure.

[0004] The current conventional technical solution is to machine a separate exhaust port on the outer wall of the differential housing. One end of this port connects to the welding chamber, while the other end is directly exposed to the outer wall of the housing. After welding, the independent exhaust port is then sealed, such as by screwing in a plug, plug welding, or adhesive bonding. However, this solution has the following inherent drawbacks: 1. Redundant processes and high costs: The external vent holes need to be processed separately, and an additional sealing process is required after welding, which prolongs the production cycle and increases processing and assembly costs.

[0005] 2. Poor sealing reliability: The screw plug is prone to loosening, and the adhesive seal is not oil-resistant or heat-resistant enough, which can easily lead to lubricating oil leakage during long-term operation.

[0006] 3. Poor sealing reliability: The screw plug is prone to loosening, and the adhesive seal is not oil-resistant or heat-resistant enough, which can easily lead to lubricating oil leakage during long-term operation.

[0007] 4. Prone to secondary defects: When plugging is used, the additional heat input will cause local thermal deformation of the housing, affecting the meshing accuracy of the main reduction gear and the coaxiality of the differential assembly. In addition, the plugging weld itself may produce new defects.

[0008] 5. Structural redundancy: The exhaust port and the pin hole used for mounting the differential are independent of each other, failing to achieve functional integration and increasing the structural complexity of the housing.

[0009] Therefore, there is an urgent need in this field for a welding vent sealing solution that requires no additional sealing process, provides reliable sealing, and eliminates the risk of thermal deformation. Summary of the Invention

[0010] The purpose of this invention is to provide an integrated differential welded exhaust sealing structure and its assembly method, so as to solve the technical problems of redundant processes, poor sealing reliability, easy thermal deformation and structural redundancy in independent exhaust port sealing schemes.

[0011] To achieve the above objectives, the present invention provides the following technical solution: an integrated differential welded exhaust sealing structure, comprising: Integral differential housing; The driven gear of the main reducer is welded to the differential housing, forming a welded annular cavity at the joint. The locating pin hole is an existing mounting locating hole on the differential housing; An exhaust mechanism for discharging exhaust gas from the welding ring cavity is provided inside the differential housing. The exhaust mechanism includes a gas ring plate communicating with the welding ring cavity, an actuating component for driving the gas ring plate, and an intake chamber and an exhaust chamber opened in the differential housing. The intake chamber and the exhaust chamber are both connected between the gas ring plate and the positioning pin hole. The pin is press-fitted into the positioning pin hole.

[0012] The positioning pin hole is a cross shaft positioning hole or a planetary gear shaft positioning hole on the differential housing, and the ports of the intake manifold and exhaust manifold are distributed on the inner wall of the positioning pin hole.

[0013] The pin is an elastic cylindrical pin, whose outer diameter in its free state is larger than the inner diameter of the positioning pin hole, and after press-fitting, it forms a full-circumference interference seal with the positioning pin hole.

[0014] The ring plate is set in a ring plate groove in the differential housing. Two ring grooves of different diameters are opened on one side of the ring plate. The intake manifold and the exhaust manifold are respectively connected to different ring grooves. An internal gear ring is set at the inner edge of the ring plate. A first L-shaped cavity and a second L-shaped cavity are opened inside the ring plate.

[0015] One end of the first L-shaped cavity sprays inert gas into the annular weld between the differential housing and the driven gear to encapsulate the weld pool. The other end of the first L-shaped cavity is connected to an annular groove. One end of the second L-shaped cavity is used to absorb the exhaust gas in the weld annular cavity. The other end of the second L-shaped cavity is connected to another annular groove.

[0016] The welding ring cavity is provided with a thin ring-shaped welding wire and a wire pusher connected to the gas ring plate. The wire pusher pushes a local section of the welding wire into the welding molten pool.

[0017] The actuating component includes a disc gear that is connected to the internal gear ring drive, a disc shaft fixed in the middle of the disc gear, a spring sleeved on the outside of the disc shaft, a retaining plate with one end inserted into a slot on the disc shaft, a piston rod fixed at the other end of the retaining plate, and multiple blocking blocks that are fixed around the inner wall of the positioning pin hole. The disc gear is distributed in the disc cavity opened at the end of the positioning pin hole in the differential housing, and the piston rod slides or rotates in the positioning pin hole.

[0018] The blocking block is inserted into a slot at the edge of the piston rod end. A prism groove is provided in the middle of one end of the piston rod for inserting a prism tool. A small annular groove is provided on the outer wall of the piston rod waist. An L-shaped small tube is provided inside the piston rod, and the L-shaped small tube connects the prism groove and the small annular groove.

[0019] The wire pusher includes a back plate fixed to the air ring plate, a spring plate fixed to one side of the back plate, and an I-beam wheel supported on the spring plate, which contacts the welding wire.

[0020] An assembly method for an integrated differential welded exhaust plug structure includes the following steps: Step 1: Gearbox assembly. The driven gear is fitted into the differential housing, forming a welded annular cavity at the joint. Step 2: Welding exhaust. Welding is performed on the mating surface between the driven gear and the differential housing. The welding exhaust gas in the welding ring cavity is discharged to the outside through the exhaust mechanism and the positioning pin hole. Step 3: Press-fit sealing. Press the pin into the positioning pin hole with an interference fit. The pin seals the exhaust port of the exhaust mechanism and simultaneously locks the internal shaft parts of the differential.

[0021] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention integrates the welded exhaust passage with the mounting pin hole of the differential itself. By using the pin that must be used during differential assembly, the exhaust passage is blocked and the internal parts are positioned simultaneously, thereby eliminating the need for a separate exhaust port and subsequent dedicated blocking process.

[0022] 2. Process integration reduces costs and increases efficiency. There is no need to process independent vent holes on the outer wall of the shell, nor is there a need for special sealing operations after welding. The venting function and the positioning pin hole function are combined into one, shortening the production cycle and reducing the cost of tools, auxiliary materials and labor.

[0023] 3. Reliable sealing with no risk of leakage. The pin adopts an elastic interference fit, forming a full-circumferential surface line contact seal with the inner wall of the pin hole. There are no problems such as loose threads, aging of the adhesive layer or cracking of the weld, which fully meets the long-term lubricating oil sealing requirements of the differential.

[0024] 4. No thermal deformation, ensuring accuracy. It eliminates heat sealing processes such as plug welding, and has no additional heat input. This avoids secondary thermal deformation of the differential housing and main reduction gear, effectively ensuring gear meshing accuracy, coaxiality and transmission stability.

[0025] 5. Simplified structure, dual-purpose design: Utilizing the original positioning pin holes and necessary pins of the differential, no additional sealing parts are required, simplifying the housing structure design and not changing the original assembly relationship and mechanical properties.

[0026] 6. It is highly versatile and adaptable, suitable for various integral differentials and main reduction gear welding structures, and can be matched with various welding processes such as carbon dioxide gas shielded welding and laser welding. It does not require modification of the main structure of the housing and is easy to be applied to existing production lines. Attached Figure Description

[0027] Figure 1 This is a schematic diagram showing the location of the positioning pin holes.

[0028] Figure 2 This is a schematic diagram showing the location of the circumferential weld.

[0029] Figure 3 This is a schematic diagram showing the location of the welding ring cavity.

[0030] Figure 4 This is a schematic diagram showing the location of the exhaust mechanism.

[0031] Figure 5 This is a schematic diagram of the exhaust mechanism.

[0032] Figure 6 This is a schematic diagram showing the position of the wire pusher.

[0033] Figure 7 This is a schematic diagram showing the location of the first L-shaped lumen.

[0034] Figure 8 This is a schematic diagram of the actuating component.

[0035] Figure 9 This is a schematic diagram of the wire pusher structure.

[0036] In the diagram: 1. Differential housing; 2. Driven gear; 3. Welded ring cavity; 4. Exhaust mechanism; 5. Locating pin hole; 6. Pin; 7. Circular weld; 8. Prism tool; 9. Gas ring plate; 101. Actuating component; 11. Intake pipe cavity; 12. Exhaust pipe cavity; 13. Ring gear; 14. First L-shaped cavity; 15. Second L-shaped cavity; 16. Disc gear; 17. Disc shaft; 18. Spring; 19. Clamping plate; 10. Piston column; 11. Block; 12. Rib groove; 13. Small ring groove; 14. L-shaped small cavity; 15. Welding wire; 16. Wire pusher; 17. Back plate; 18. Spring; 19. I-beam wheel; 10. Detailed Implementation

[0037] 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 technical solutions 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.

[0038] Please see Figures 1 to 9 This invention provides a technical solution: an integrated differential welding exhaust sealing structure and its assembly method, which is illustrated using an integral differential of a light commercial vehicle drive axle as an example.

[0039] The integral differential housing 1 and the driven gear 2 of the main reducer are welded together by an annular weld 7. The welded annular cavity 3 formed by the two is an annular closed cavity. The positioning pin hole 5 is a cross shaft positioning hole. The pin 6 is a standard elastic cylindrical pin. Its outer diameter in the free state is larger than the inner diameter of the pin hole. After being pressed into the positioning pin hole 5, it forms a full circumferential interference seal.

[0040] After sealing and positioning are completed, the remaining components such as bearings and oil seals are then assembled.

[0041] The exhaust mechanism 4 is used to discharge the exhaust gas in the welding ring cavity 3. The exhaust mechanism 4 is located inside the differential housing 1. The exhaust mechanism 4 includes a gas ring plate 401 that communicates with the welding ring cavity 3, an actuating component 402 for driving the gas ring plate 401, and an intake pipe cavity 403 and an exhaust pipe cavity 404 opened in the differential housing 1. The intake pipe cavity 403 and the exhaust pipe cavity 404 are both connected between the gas ring plate 401 and the positioning pin hole 5.

[0042] The positioning pin hole 5 is a cross shaft positioning hole or planetary gear shaft positioning hole on the differential housing 1. The ports of the intake manifold 403 and the exhaust manifold 404 are distributed on the inner wall of the positioning pin hole 5.

[0043] Reference Appendix Figure 3 It is understood that pin 6 is an elastic cylindrical pin, whose outer diameter in its free state is larger than the inner diameter of the positioning pin hole 5, and after being press-fitted, it forms a full-circumference interference seal with the positioning pin hole 5.

[0044] Reference Appendix Figure 5 It is understood that the piston ring plate 401 is set in the ring plate groove opened in the differential housing 1. Two ring grooves 411 with different diameters are opened on one side of the piston ring plate 401. The intake pipe cavity 403 and the exhaust pipe cavity 404 are respectively connected to different ring grooves 411. An internal gear ring 412 is provided at the inner edge of the piston ring plate 401. A first L-shaped cavity 413 and a second L-shaped cavity 414 are opened inside the piston ring plate 401.

[0045] One end of the first L-shaped cavity 413 sprays inert gas into the annular weld seam 7 between the differential housing 1 and the driven gear 2 to encapsulate the weld pool. The other end of the first L-shaped cavity 413 is connected to an annular groove 411. One end of the second L-shaped cavity 414 is used to absorb the exhaust gas in the welding annular cavity 3. The other end of the second L-shaped cavity 414 is connected to another annular groove 411.

[0046] The welding ring cavity 3 is provided with a thin ring-shaped welding wire 701 and a wire pusher 702 connected to the gas ring plate 401. The wire pusher 702 pushes a local section of the welding wire 701 into the welding molten pool.

[0047] The actuating component 402 includes a disc gear 421 that is connected to the internal gear ring 412, a disc shaft 422 fixed in the middle of the disc gear 421, a spring 423 sleeved on the outside of the disc shaft 422, a retaining plate 424 with one end inserted into a groove on the disc shaft 422, a piston rod 425 fixed at the other end of the retaining plate 424, and a plurality of blocking blocks 426 that are fixed around the inner wall of the positioning pin hole 5. The disc gear 421 is distributed in the disc cavity opened at the end of the positioning pin hole 5 in the differential housing 1, and the piston rod 425 slides or rotates in the positioning pin hole 5.

[0048] The stop block 426 is locked in the groove opened at the end edge of the piston column 425. A prism groove 451 for inserting the prism tool 8 is opened in the middle of one end of the piston column 425. A small annular groove 452 is opened on the outer wall of the waist of the piston column 425. An L-shaped small tube 453 is opened inside the piston column 425. The L-shaped small tube 453 connects the prism groove 451 and the small annular groove 452.

[0049] The wire pusher 702 includes a back plate 721 fixed on the air ring plate 401, a spring piece 722 fixed on one side of the back plate 721, and an I-beam wheel 723 supported on the spring piece 722. The I-beam wheel 723 is in contact with the welding wire 701.

[0050] When welding the annular weld 7, the welding point gradually moves along the annular path. The first L-shaped cavity 413 sprays protective inert gas towards the welding point, and the first L-shaped cavity 413 also moves in a circular motion. Specifically, the transmission is as follows: the prism tool 8 is inserted into the positioning pin hole 5 from the outside, the prism end of the prism tool 8 is inserted into the prism groove 451, the gas supply pipe is opened at the axis of the prism tool 8, the prism end of the prism tool 8 pushes the piston column 425, the piston column 425 moves axially towards the disc gear 421, after the piston column 425 and the stop block 426 separate, the prism tool 8 drives the piston column 425 to rotate. The movement is initiated by the movement of the disc shaft 422 via the clamping plate 424. The disc gear 421 then drives the air ring plate 401. As the air ring plate 401 rotates, the first L-shaped cavity 413 and the welding point move synchronously. Inert gas is supplied to the prism tool 8 through the existing inert gas supply mechanism. The inert gas is then injected into the L-shaped small cavity 453, and then into the air inlet cavity 403 through the small annular groove 452. Subsequently, it is injected into the second L-shaped cavity 414 through the small diameter annular groove 411. The second L-shaped cavity 414 then sprays inert gas onto the welding point, covering the weld pool and forming an isolation protection.

[0051] The hot exhaust gas generated at the welding point is transferred and discharged. The exhaust gas in the welding ring cavity 3 is discharged into the second L-shaped pipe cavity 414, and then through the large-diameter ring groove 411 into the exhaust pipe cavity 404, and then through the positioning pin hole 5 to the outside.

[0052] After the piston rod 425 is reset, it is blocked by the block 426, so the piston rod 425 cannot rotate. Then, the disc shaft 422 is limited by the clamping plate 424, and then the gas ring plate 401 is limited by the disc gear 421 to prevent the gas ring plate 401 from slipping and rotating when the differential housing 1 is working.

[0053] The H-beam 723 is distributed on one side of the molten pool at the welding point. The high temperature in the molten pool melts a local section of the welding wire 701. The spring 722 continuously applies pressure to the H-beam 723, melting the local section of the welding wire 701 in the molten pool. Then, the H-beam 723 gradually pushes the local section of the welding wire 701 into the molten pool, increasing the material density in the molten pool. After the molten pool cools down, the differential housing 1 and the driven gear 2 are more firmly connected.

[0054] An assembly method for an integrated differential welded exhaust plug structure includes the following steps: Step 1: Gearbox assembly. The driven gear 2 is fitted into the differential housing 1, forming a welded annular cavity 3 at the joint. Step 2: Welding exhaust. Welding operation is carried out on the mating surface of the driven gear 2 and the differential housing 1. The welding exhaust gas in the welding ring cavity 3 is discharged to the outside through the exhaust mechanism 4 and the positioning pin hole 5. Step 3: Press-fit sealing. Press-fit the pin 6 into the positioning pin hole 5 with an interference fit. The pin 6 seals the exhaust port of the exhaust mechanism 4 and simultaneously locks the internal shaft parts of the differential.

[0055] Alternative implementation methods: When the welding chamber is large or the exhaust demand is high, the exhaust mechanism 4 is provided with multiple exhaust paths. Each exhaust path consists of a second L-shaped cavity 414, an exhaust cavity 404, and an annular groove 411 connecting the two. All exhaust paths are connected to the same positioning pin hole 5. The positioning pin hole 5 is not limited to the cross shaft positioning hole, but can also be the half shaft gear positioning hole or the housing box positioning hole. As long as it is a hole that is originally in the differential or needs to be positioned by a pin, the same sealing effect can be achieved. To improve the smoothness of pin pressing, a chamfer or guide structure can be installed at the vent outlet.

[0056] 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. An integrated differential welded exhaust sealing structure, characterized in that, Including: Integral differential housing; The driven gear of the main reducer is welded to the differential housing, forming a welded annular cavity at the joint. The locating pin hole is an existing mounting locating hole on the differential housing; An exhaust mechanism for discharging exhaust gas from the welding ring cavity is provided inside the differential housing. The exhaust mechanism includes a gas ring plate communicating with the welding ring cavity, an actuating component for driving the gas ring plate, and an intake chamber and an exhaust chamber opened in the differential housing. The intake chamber and the exhaust chamber are both connected between the gas ring plate and the positioning pin hole. The pin is press-fitted into the positioning pin hole; The ring plate is set in the ring plate groove opened in the differential housing. Two ring grooves of different diameters are opened on one side of the ring plate. The intake pipe cavity and the exhaust pipe cavity are respectively connected to different ring grooves. An internal toothed ring is set at the inner edge of the ring plate. A first L-shaped cavity and a second L-shaped cavity are opened inside the ring plate. One end of the first L-shaped cavity sprays inert gas into the annular weld between the differential housing and the driven gear to encapsulate the weld pool. The other end of the first L-shaped cavity is connected to an annular groove. One end of the second L-shaped cavity is used to absorb the exhaust gas in the weld annular cavity. The other end of the second L-shaped cavity is connected to another annular groove. The actuating component includes a disc gear that is connected to the internal gear ring drive, a disc shaft fixed in the middle of the disc gear, a spring sleeved on the outside of the disc shaft, a retaining plate inserted into a slot on the disc shaft at one end, a piston rod fixed at the other end of the retaining plate, and multiple blocking blocks that are fixed around the inner wall of the positioning pin hole. The disc gear is distributed in the disc cavity opened at the end of the positioning pin hole in the differential housing, and the piston rod slides or rotates in the positioning pin hole. The blocking block is inserted into a slot at the edge of the piston rod end. A prism groove is provided in the middle of one end of the piston rod for inserting a prism tool. A small annular groove is provided on the outer wall of the piston rod waist. An L-shaped small tube is provided inside the piston rod, and the L-shaped small tube connects the prism groove and the small annular groove.

2. The integrated differential welded exhaust sealing structure according to claim 1, characterized in that: The positioning pin hole is a cross shaft positioning hole or a planetary gear shaft positioning hole on the differential housing, and the ports of the intake manifold and exhaust manifold are distributed on the inner wall of the positioning pin hole.

3. The integrated differential welded exhaust sealing structure according to claim 1, characterized in that: The pin is an elastic cylindrical pin, whose outer diameter in its free state is larger than the inner diameter of the positioning pin hole, and after press-fitting, it forms a full-circumference interference seal with the positioning pin hole.

4. The integrated differential welded exhaust sealing structure according to claim 1, characterized in that: The welding ring cavity is provided with a thin ring-shaped welding wire and a wire pusher connected to the gas ring plate. The wire pusher pushes a local section of the welding wire into the welding molten pool.

5. The integrated differential welded exhaust sealing structure according to claim 4, characterized in that: The wire pusher includes a back plate fixed to the air ring plate, a spring plate fixed to one side of the back plate, and an I-beam wheel supported on the spring plate, which contacts the welding wire.

6. A method for assembling an integrated differential welded exhaust sealing structure, used in the integrated differential welded exhaust sealing structure as described in claim 1, characterized in that, Includes the following steps: Step 1: Gearbox assembly. The driven gear is fitted into the differential housing, forming a welded annular cavity at the joint. Step 2: Welding exhaust. Welding is performed on the mating surface between the driven gear and the differential housing. The welding exhaust gas in the welding ring cavity is discharged to the outside through the exhaust mechanism and the positioning pin hole. Step 3: Press-fit sealing. Press the pin into the positioning pin hole with an interference fit. The pin seals the exhaust port of the exhaust mechanism and simultaneously locks the internal shaft parts of the differential.

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