Welding repair process method for rear oil seal of diesel engine

Abstract

The invention belongs to the field of locomotive maintenance, and particularly discloses a diesel engine rear oil seal welding repair process method which comprises the following steps: heating a diesel engine rear oil seal to fully separate out grease in a part and ensure that weld metal is well fused with base metal; during welding, the rear oil seal is inverted, and the supporting plate is additionally arranged at the oil collecting groove to prevent welding fluid at a welding seam from flowing downwards; during welding, a transverse surfacing mode is adopted, so that the welding seam thickness can be quickly increased, and the welding seam quality can be conveniently observed; and a surfacing method is adopted at the joint surface, so that the deformation caused by welding is solved, the quality after welding is ensured, and the welding method is high in repairing efficiency and good in repairing effect.

Description

Technical Field

[0001] The invention belongs to the field of locomotive maintenance, and in particular relates to a diesel engine rear oil seal welding repair process method. Background Art

[0002] The rear oil seal is made of cast aluminum ZL104, which is mainly used for sealing the diesel engine output end body and crankshaft. After the rear oil seal has been used for a period of time, the inner hole of the rear oil seal will be worn, causing the inner hole size to increase, thereby reducing its sealing performance and causing oil leakage. Welding is generally used for repair, but the difficulties that may occur during welding repair are: (1) There is no obvious color change during welding, and the welding liquid is easy to fall and form weld nodules and collapse; (2) The deformation after welding is large and there is a gap in the joint; (3) Hydrogen pores are easily formed between welds; (4) After the rear oil seal is used, the internal structure is soaked in oil, making it difficult for the welds to fuse. Summary of the invention

[0003] In view of the problems existing in the background technology, the present invention provides a diesel engine rear oil seal welding repair process method.

[0004] To achieve the above-mentioned purpose, the present invention adopts the following technical scheme: a diesel engine rear oil seal welding repair process method, the diesel engine rear oil seal comprises a rear oil seal upper body and a rear oil seal lower body, a rear oil seal inner hole is arranged in the middle of the rear oil seal upper body and the rear oil seal lower body, an oil collecting groove is arranged in the middle of the rear oil seal inner hole, the lower part of the oil collecting groove is a lower inner hole surface, and the upper part of the oil collecting groove is an upper inner hole surface, the diesel engine rear oil seal welding repair process method comprises the following steps: step S1, oil control: separate the diesel engine rear oil seal upper body and the rear oil seal lower body, and place them in a box-type heating furnace for heating; Step S2, pre-welding processing: installing the rear oil seal upper body on the upper end surface of the rear oil seal lower body, processing the rear oil seal inner holes in the middle of the rear oil seal upper body and the rear oil seal lower body, and eliminating the pores, cracks and looseness of the sealing groove of the rear oil seal inner hole; Step S3, pre-welding treatment: removing the surface oxide film on the cladding surface and the surrounding 30mm surface; Step S4, welding the inner wall of the inner hole of the rear oil seal: separating the upper body and the lower body of the rear oil seal of the diesel engine; the specific operation steps are as follows: a1. Welding of the lower layer: When welding the lower inner hole surface, place the rear oil seal upside down on the workbench; when welding the upper inner hole surface, place a support plate in the oil collecting tank; a2. Welding of the middle layer: single-layer multi-pass welding from bottom to top; a3. Surfacing welding of the joint surface between the rear oil seal upper body and the rear oil seal lower body: Place the rear oil seal upper body and the rear oil seal lower body vertically, so that the joint surface between the rear oil seal upper body and the rear oil seal lower body is in the flat welding position, and then weld; Step S5, post-weld inspection: after welding is completed, the weld is inspected to see if there are pores, cracks, lack of fusion and lack of weld. If any defects are found, they are repaired in time. Step S6: Post-welding processing: machining the upper body and the lower body of the rear oil seal so that the inner hole of the rear oil seal meets the process requirements, and performing color flaw detection on the machined surface.

[0005] In the step S1, the heating temperature in the heating furnace is not less than 200° C., and the heating time is not less than 30 minutes.

[0006] In the step S4, metal inert gas (MIG) welding is adopted, the purity of argon gas is ≥99.99%, the flow rate is 18L / min, the welding material is ER4047, and the electrode diameter is 1.2mm.

[0007] In the step a1, the welding current is 120-130A, the angle between the welding gun and the bottom surface is 45°-50°, and the welding thickness is 5mm.

[0008] In step a2, the welding current is 120-140A, the welding gun and the cladding surface form an angle of 40º-50º, the weld covers 1 / 2-2 / 3 of the highest point of the weld in step a1, and the welding thickness is greater than 3mm.

[0009] In step a3, the welding current is 120-140A, the angle between the welding gun and the cladding surface is 40°-50°, and the welding thickness is 3mm.

[0010] Beneficial effects of the invention: The invention provides a diesel engine rear oil seal welding repair process method, the welding repair process method first heats the diesel engine rear oil seal to allow the grease inside the component to be fully released, ensuring good fusion of the weld metal and the parent material; when welding, the rear oil seal is inverted, and a support plate is added to the oil collecting tank to prevent the welding liquid at the weld from dripping; when welding, a horizontal surfacing method is adopted, which is not only conducive to quickly increasing the weld thickness, but also convenient for observing the weld quality; the surfacing method is adopted at the joint surface to solve the deformation caused by welding and ensure the quality after welding. The welding method has high repair efficiency and good repair effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 This is a schematic diagram of the diesel engine rear oil seal structure.

[0012] Figure 2 This is a structural diagram of the diesel engine rear oil seal during welding repair.

[0013] Figure 3It is a schematic diagram of the cross-sectional structure of the inner hole surface of the rear oil seal of a diesel engine.

[0014] Figure 4 This is a schematic diagram of the surfacing area of ​​the rear oil seal joint of a diesel engine.

[0015] Figure 5 This is a schematic diagram of the support plate used for welding the rear oil seal of a diesel engine.

[0016] In the figure: 1. upper body of rear oil seal, 2. lower body of rear oil seal, 3. joint surface, 4. inner hole of rear oil seal, 41. lower inner hole surface, 42. upper inner hole surface, 6. oil collecting groove, 7. support plate. DETAILED DESCRIPTION

[0017] The technical solution of the present invention will be clearly and completely described below in conjunction with the drawings in the specification. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments; based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0018] The following is combined with Figure 1-5 The specific implementation mode of the present invention is further elaborated in detail: a diesel engine rear oil seal welding repair process method, the diesel engine rear oil seal comprises a rear oil seal upper body 1 and a rear oil seal lower body 2, the middle of the rear oil seal upper body 1 and the rear oil seal lower body 2 is provided with a rear oil seal inner hole 4, the middle of the rear oil seal inner hole 4 is provided with an oil collecting groove 6, the lower part of the oil collecting groove 6 is a lower inner hole surface 41, and the upper part of the oil collecting groove 6 is an upper inner hole surface 42, comprising the following steps: step S1, oil control: separate the diesel engine rear oil seal upper body 1 and the rear oil seal lower body 2, place them in a box-type heating furnace for heating; the heating temperature in the heating furnace is not less than 200°C, and the heating time is not less than 30 minutes, so that the rear oil seal surface and the oil immersed in the parent material can be fully separated out; Step S2, pre-welding processing: installing the rear oil seal upper body 1 on the upper end surface of the rear oil seal lower body 2, processing the rear oil seal inner hole 4 in the middle of the rear oil seal upper body 1 and the rear oil seal lower body 2, and eliminating the pores, cracks and looseness of the sealing groove of the rear oil seal inner hole 4; Step S3, pre-welding treatment: remove the surface oxide film on the cladding surface and the surrounding 30mm; before welding, use a grinder, stainless steel wire brush or milling cutter to remove the oxide film on the welding surface and the surrounding 30mm to expose the original color of the parent material; Step S4, welding the inner wall of the rear oil seal inner hole 4: Separate the diesel engine rear oil seal upper body 1 and the rear oil seal lower body 2; adopt melt inert gas shielded welding (MIG) welding, argon purity ≥ 99.99%, flow rate 18L / min, welding material: ER4047, diameter: 1.2mm; the specific operation steps are as follows: a1. Welding of the lower layer: When welding the lower inner hole surface 41, place the rear oil seal upside down on the workbench; Figure 2 , the polished rear oil seal top surface is brought into contact with the workbench, the welding current is 120-130A, the welding gun angle is 45º-50º with the bottom surface, the arc is directed to the root and moves forward evenly in a straight line or straight back and forth, the weld is formed by the gravity of the molten pool metal, and the welding thickness is about 5mm; when welding the upper inner hole surface 42, a support plate 7 is pre-placed in the oil collecting tank 6; the welding parameters, welding gun angle, and welding rod feeding method are the same as those of the lower inner hole surface 41; a2. Welding of the middle layer: adopt single-layer multi-pass welding from bottom to top; to improve the cladding efficiency, the welding current is 120-140A, welding is performed from right to left, the angle between the welding gun and the cladding surface is 40º-50º, and the arc must swing up and down in a crescent shape along the fusion line between the weld and the parent material to ensure good fusion of the weld and the parent material, so that the weld covers 1 / 2-2 / 3 of the highest point of the weld in step a1 to avoid the formation of grooves between welds; the welding thickness is greater than 3mm; a3. Overlay welding of the joint surface 3 between the rear oil seal upper body 1 and the rear oil seal lower body 2: Place the rear oil seal upper body 1 and the rear oil seal lower body 2 vertically, so that the joint surface 3 between the rear oil seal upper body 1 and the rear oil seal lower body 2 is in the flat welding position, and then weld; the overlay welding area is the 1 / 2 shaded part close to the rear oil seal inner hole 4 side, such as Figure 4 , single-layer multi-pass welding is adopted, first the periphery of the welding area is welded in a circle, and then the middle part is welded, the welding current is 120-140A, the angle between the welding gun and the cladding surface is 40º-50º, and the welding thickness is kept at about 3mm; In the above welding process, the edges should be free of any lack of meat; if there are casting defects or local non-fusion, the defects should be removed in time; Step S5: Post-weld inspection: After welding is completed, the weld is inspected to see if there are any pores, cracks, incomplete fusion, or missing welds. If any defects are found, they should be repaired in time. Step S6: Post-welding processing: The rear oil seal upper body 1 is mounted on the upper end surface of the rear oil seal lower body 2, and machined so that the rear oil seal inner hole 4 meets the process requirements, and the machined surface is subjected to color flaw detection inspection.

[0019] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

[0020] The parts not described in detail in this invention are prior art.

Claims

1. A diesel engine rear oil seal welding repair process method, the diesel engine rear oil seal comprising a rear oil seal upper body (1) and a rear oil seal lower body (2), a rear oil seal inner hole (4) is provided in the middle of the rear oil seal upper body (1) and the rear oil seal lower body (2), an oil collecting groove (6) is provided in the middle of the rear oil seal inner hole (4), the lower part of the oil collecting groove (6) is a lower inner hole surface (41), and the upper part of the oil collecting groove (6) is an upper inner hole surface (42), the diesel engine rear oil seal welding repair process method is characterized by: The following steps are involved: Step S1, oil control: separate the diesel engine rear oil seal upper body (1) and the rear oil seal lower body (2), and place them in a box-type heating furnace for heating; Step S2, pre-welding processing: installing the rear oil seal upper body (1) on the upper end surface of the rear oil seal lower body (2), processing the rear oil seal inner hole (4) in the middle of the rear oil seal upper body (1) and the rear oil seal lower body (2), and eliminating the air holes, cracks and looseness of the sealing groove of the rear oil seal inner hole (4); Step S3, pre-welding treatment: removing the surface oxide film on the cladding surface and the surrounding 30mm surface; Step S4, welding the inner wall of the rear oil seal inner hole (4): separating the diesel engine rear oil seal upper body (1) and the rear oil seal lower body (2); the specific operation steps are as follows: a1. Welding of the lower layer: When welding the lower inner hole surface (41), the rear oil seal is inverted on the workbench; when welding the upper inner hole surface (42), a support plate (7) is placed in the oil collecting tank (6); a2. Welding of the middle layer: single-layer multi-pass welding from bottom to top; a3. Surfacing welding of the joint surface (3) between the rear oil seal upper body (1) and the rear oil seal lower body (2): the rear oil seal upper body (1) and the rear oil seal lower body (2) are placed vertically so that the joint surface (3) between the rear oil seal upper body (1) and the rear oil seal lower body (2) are in a flat welding position, and welding is performed; Step S5, post-weld inspection: after welding is completed, the weld is inspected to see if there are pores, cracks, lack of fusion and lack of weld. If any defects are found, they are repaired in time. Step S6: post-welding processing: machining the rear oil seal upper body (1) and the rear oil seal lower body (2) so that the rear oil seal inner hole (4) meets the process requirements, and performing color flaw detection on the machined surface.

2. According to claim 1, a diesel engine rear oil seal welding repair process method is characterized by: In the step S1, the heating temperature in the heating furnace is not less than 200° C., and the heating time is not less than 30 minutes.

3. According to claim 1, a diesel engine rear oil seal welding repair process method is characterized by: In the step S4, metal inert gas (MIG) welding is adopted, the purity of argon gas is ≥99.99%, the flow rate is 18L / min, the welding material is ER4047, and the electrode diameter is 1.2mm.

4. According to claim 1, a diesel engine rear oil seal welding repair process method is characterized by: In the step a1, the welding current is 120-130A, the angle between the welding gun and the bottom surface is 45°-50°, and the welding thickness is 5mm.

5. According to claim 1, a diesel engine rear oil seal welding repair process method is characterized by: In step a2, the welding current is 120-140A, the welding gun and the cladding surface form an angle of 40º-50º, the weld covers 1 / 2-2 / 3 of the highest point of the weld in step a1, and the welding thickness is greater than 3mm.

6. The diesel engine rear oil seal welding repair process according to claim 1 is characterized by: In step a3, the welding current is 120-140A, the angle between the welding gun and the cladding surface is 40°-50°, and the welding thickness is 3mm.

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