WO2019185059A1

WO2019185059A1 - Welding process for differential assembly

Info

Publication number: WO2019185059A1
Application number: PCT/CN2019/080629
Authority: WO
Inventors: 邱丽娜
Original assignee: 重庆联豪科技有限公司
Priority date: 2018-03-30
Filing date: 2019-03-29
Publication date: 2019-10-03
Also published as: JP2020523201A; CN108500576A; DE112019000066T5

Abstract

The present invention relates to the technical field of automobile accessory manufacturing. Disclosed is a welding process for a differential assembly, comprising the following steps: (1) preparing a differential housing and a differential gear matching each other; (2) laser cleaning; (3) press-fitting; (4) welding wire filling and laser spot welding; (5) round welding; (6) cleaning a welding seam; (7) ultrasonic flaw detection; and (8) gear grinding. Compared with the prior art, the process is simple in operation so that the differential assembly produced by the process is simple in structure, low in processing costs, high in precision, and lighter in weight.

Description

Welding process of differential assembly

Technical field

The invention belongs to the technical field of automobile parts manufacturing, and specifically discloses a welding process of a differential assembly.

Background technique

The differential assembly is an important and indispensable component in the car to realize turning and changing of the car, and is mainly composed of a differential case and a differential gear. At present, the differential housings on automobiles are mostly ductile iron (such as QT500 and QT600), and the differential gears are mostly low carbon steel (such as 20CrMoH, 20MnCr5). Usually, the differential gear and the differential housing are The connection is made by connecting the differential gear to the differential housing with bolts or rivets. Conventional screw or rivet-connected differential assemblies have the following disadvantages:

1. The differential housing and the differential gear require complicated machining processes such as drilling, tapping and assembly, which are difficult to process and costly.

2. The traditional differential assembly, due to the existence of bolts, rivets and other structures, the overall size of the differential assembly can not be small, otherwise it will be difficult to process, which results in the weight of the differential assembly, large volume, It is difficult to adapt to the current small and lightweight requirements for new energy and high-end vehicles.

3. The conventional differential assembly is to assemble the differential gear after finishing (grinding) to the differential housing. The accuracy of the differential gear is reduced due to the error of the installation, which affects the use of the automobile.

4. In the automobile using the traditional differential assembly, the bolts are subjected to large shearing force during the running of the automobile, which is a wearing part, and the replacement is time-consuming and laborious, and the replacement cost is high.

Summary of the invention

The object of the present invention is to provide a welding process for a differential assembly to solve the conventional differential assembly, which is difficult to process, high in cost, low in precision, and difficult to be lightweight.

In order to achieve the above object, the basic solution of the present invention is: a welding process of a differential assembly, comprising the following steps:

(1) Preparing a differential housing and a differential gear that are matched to each other, and the outside of the differential housing is a stepped shaft portion;

(2) removing oil stains and carbon layers on the differential case and the differential gear, and performing laser cleaning until the contact faces of the differential case and the differential gear are free of foreign matter and impurities;

(3) arranging the shaft hole of the differential gear on the stepped shaft portion having a smaller diameter of the differential housing, and pressing the step of the differential gear and the stepped shaft portion;

(4) A 0.6-1.5 mm iron-nickel alloy welding wire is filled into the gap of the contact surface of the differential case and the differential gear by a wire filling mechanism, and the differential case is spot-welded by a laser. Welding with the contact surface of the differential gear;

(5) After the spot welding is completed, all the contact faces of the differential case and the differential gear are welded by ring welding;

(6) Clean the weld, brush the weld with a brush, and remove the weld residue around the weld;

(7) Ultrasonic flaw detection, using an ultrasonic sounder perpendicular to the weld and passing through all welds to probe the weld quality of the differential gear and the differential housing;

(8) After the ring welding is completed, the differential gear is ground to make the differential gear meet the accuracy standard of 3-7 in GB/T 10095.1-2008/ISO 1328-1:1995.

The beneficial effects of this basic program are:

1. The differential assembly is fixedly connected by the differential gear of the low carbon steel and the differential housing of the ductile iron, which reduces the drilling and threading of the differential housing and the differential gear. The processing, as well as the assembly of the differential housing and the differential gear, further avoids the accuracy of the differential assembly due to machining and assembly, reduces production costs, and improves production efficiency and machining accuracy.

2. The differential assembly produced by welding reduces the bolt structure, which makes the differential assembly produced more compact and lighter in overall quality, and can be reduced according to the structural needs of the electric vehicle. The size of the differential assembly allows the differential assembly to be used in a wide range.

3. The structure of the differential assembly produced by welding is relatively simple, easy to produce, and the joint strength of the casing and the gear is improved by welding, so that the differential assembly produced is more durable.

4. After the high-temperature dissolution of the nickel-iron alloy, the differential housing of the different materials and the differential gear can be welded together, so that the welding strength of the differential housing and the differential gear can meet the required requirements.

5. Spot welding the contact surface of the differential gear and the differential case first, and then performing ring welding to avoid relative displacement of the differential gear and the differential case during the welding process, resulting in poor welding. The speed changer assembly is deformed and the accuracy is not up to the required requirements. At the same time, the differential gear and the differential case can be welded and fixed together more firmly.

Compared with the prior art, the process is simple in operation, and the differential assembly produced can be simple in structure, low in processing cost, high in precision, and light in total.

Preferably, as a basis of the basic solution, in step (4), after filling the welding wire, the contact faces of the differential case and the differential gear are evenly divided into 3-8 points for spot welding. Spot welding is more effective in preventing relative displacement of the differential housing and the differential gear during welding.

Preferably, in a second embodiment, in the step (5), the differential case and the differential gear are clamped by a clamp, and a laser beam is used to wrap around the weld to dissolve the iron-nickel alloy wire. The differential gear and the differential housing are welded and fixed. The welding process can be made more fast and stable, so that the differential gear and the differential housing have better welding quality and higher processing efficiency.

Preferred Embodiment 3: As a preferred embodiment 2, in the steps (5) and (6), the position of the welding is located at an axial contact surface of the differential gear and the differential case. When the differential gear and the differential housing are subjected to relative forces, the axial contact faces of the two are the points of force, where welding can make the differential gear and the differential housing more durable.

Preferably, in a preferred embodiment 3, the differential housing and the differential gear weld are located at the end of the stepped shaft bore having a small diameter. Here, the differential housing and the differential gear are closely attached, which makes it easier to weld and also makes the connection between the two more secure.

Preferred Embodiment 5: As a preferred embodiment 4, the weld depth of the differential housing and the differential gear weld is 5 ± 0.5 mm. The connection strength of the differential case and the differential gear is further satisfied.

Preferred Embodiment 6: As a preferred embodiment 2, in the steps (5) and (6), the position of the welding is located at a radial contact surface of the differential gear and the differential case. The welding port can be made facing outward to facilitate the welding operation; and when the differential assembly is in use, the differential gear and the differential housing are relatively stressed, and the radial position of the contact surface is welded, which can effectively offset the relative Forced to make the differential assembly more durable.

Preferred Solution 7: As a preferred embodiment 6, the welded portion of the gear and the housing has a weld depth of 6 ± 0.5 mm. It further ensures that the welded connection between the housing and the gear is relatively firm.

DRAWINGS

1 is a schematic structural view of a differential assembly processed by the welding process of Embodiment 1;

Figure 2 is an enlarged view of the structure at A in Figure 1;

3 is a schematic structural view of a differential assembly processed by the welding process of Embodiment 5;

Figure 4 is an enlarged view of the structure at B in Figure 1.

detailed description

The present invention will be further described in detail below by way of specific embodiments:

Reference numerals in the drawings of the specification include: a differential gear 1, a differential case 2, and a weld bead 3.

Example 1

A welding process for a differential assembly includes the following steps:

(1) Preparing the differential housing 2 and the differential gear 1 that are compatible with each other, and the outside of the differential housing 2 is a stepped shaft portion;

(2) removing the oil stain and carbon layer on the differential case 2 and the differential gear 1, and performing laser cleaning until the contact faces of the differential case 2 and the differential gear 1 are free from foreign matter and impurities;

(3) arranging the shaft hole of the differential gear 1 on the stepped shaft portion of the differential housing 2 having a small diameter, and pressing the step of the differential gear 1 and the stepped shaft portion;

(4) The differential gear 1 and the differential case 2 are fixed by a jig, and a 1 mm iron-nickel alloy welding wire is filled into the axial contact surface of the differential case 2 and the differential gear 1 by a wire filling mechanism. In the gap, the contact faces of the differential case 2 and the differential gear 1 are evenly divided into 4 points for spot welding; the differential case 2 and the differential gear 1 are welded at the small diameter end of the stepped shaft hole. unit;

(5) After the spot welding is completed, the machine tool is used to make the laser beam for welding go around the weld 3 of the differential assembly, and the iron-nickel alloy welding wire is completely dissolved at a high temperature, and the differential case is assembled. 2 and all the axial contact faces of the differential gear 1 are connected together, the effective weld 3 depth at the weld is 5 ± 0.5 mm;

(6) Clean the weld 3, use the clamp to grab the differential assembly and rotate it, and use the brush to contact the weld 3. During the rotation of the differential assembly, the brush will scrub the weld 3 and remove the weld 3 Welding slag

(7) Ultrasonic flaw detection, using the clamp to grab the differential assembly and rotating, using the ultrasonic sounder perpendicular to the weld 3. During the rotation of the differential assembly, the ultrasonic waves will sweep through all the welds 3, and the difference is detected. The quality of the weld 3 of the speed gear 1 and the differential case 2; if the weld 3 has cracks, pores, and the weld 3 does not meet the required effective depth, it can be scrapped and recovered; if the weld 3 The absence of cracks, pores, and the requirement that the weld bead 3 meet the required effective depth will prove that the weld meets the required requirements;

(8) After the ring welding is completed, the differential gear 1 is ground and processed, and then the welded differential assembly is shot blasted to make the differential gear 1 reach GB/T 10095.1-2008/ ISO 1328-1: 1995 accuracy standards for grades 3-7.

Example 2

The present embodiment is different from the first embodiment in that, in the step (4), a 0.6 mm iron-nickel alloy welding wire is filled into the axial contact surface of the differential case 2 and the differential gear 1 by a wire filling mechanism. In the slit, the contact faces of the differential case 2 and the differential gear 1 are evenly divided into three points for spot welding.

According to the current common dimensions of the differential case 2 and the differential gear 1, the three points of the contact surface of the differential case 2 and the differential gear 1 are spot-welded, so that both are good. Initial fixation; the use of 0.6mm iron-nickel alloy wire can make the welding process faster.

Example 3

The present embodiment is different from the first embodiment in that, in the step (4), a 1.3 mm iron-nickel alloy welding wire is filled into the axial contact surface of the differential case 2 and the differential gear 1 by a wire filling mechanism. In the slit, the contact faces of the differential case 2 and the differential gear 1 are evenly divided into 6 points for spot welding.

Spot welding the 6 points of the contact surface of the differential case 2 and the differential gear 1 can be applied to a plurality of differential assemblies, and a 1.3 mm iron-nickel alloy welding wire can be used to make the welding process more Firm.

Example 4

The present embodiment is different from the first embodiment in that, in the step (4), a 1.5 mm iron-nickel alloy welding wire is filled into the axial contact surface of the differential case 2 and the differential gear 1 by a wire filling mechanism. In the slit, the contact faces of the differential case 2 and the differential gear 1 are evenly divided into 8 points for spot welding.

Spot welding of 8 points of the contact surface of the differential case 2 and the differential gear 1 to meet a larger differential assembly, using a 1.5 mm iron-nickel alloy welding wire, which can be of a larger size The differential assembly is more robustly welded.

Example 5

The present embodiment is different from Embodiment 1 in that, in the steps (5) and (6), the position of the welding is located at the radial contact surface of the differential gear 1 and the differential case 2; The weld seam 3 at the weld of the casing has a depth of 6 ± 0.5 mm.

The differential assembly manufactured by the welding process of this embodiment is shown in FIGS. 3 and 4.

The above description is only the embodiments of the present invention, and common knowledge of specific structures and characteristics well known in the schemes is not described herein. It should be noted that a number of variations and modifications may be made by those skilled in the art without departing from the scope of the invention, and these should also be regarded as the scope of the invention, which does not affect the practice of the invention. The effectiveness of the effect and patents.

Claims

A welding process for a differential assembly, characterized in that it comprises the following steps:

(1) Preparing a differential housing and a differential gear that are matched to each other, and the outside of the differential housing is a stepped shaft portion;

(2) removing oil stains and carbon layers on the differential case and the differential gear, and performing laser cleaning until the contact faces of the differential case and the differential gear are free of foreign matter and impurities;

(3) arranging the shaft hole of the differential gear on the stepped shaft portion having a smaller diameter of the differential housing, and pressing the step of the differential gear and the stepped shaft portion;

(4) A 0.6-1.5 mm iron-nickel alloy welding wire is filled into the gap of the contact surface of the differential case and the differential gear by a wire filling mechanism, and the differential case is spot-welded by a laser. Welding with the contact surface of the differential gear;

(5) After the spot welding is completed, all the contact faces of the differential case and the differential gear are welded by ring welding;

(6) Clean the weld, brush the weld with a brush, and remove the weld residue around the weld;

(7) Ultrasonic flaw detection, using an ultrasonic sounder perpendicular to the weld and passing through all welds to probe the weld quality of the differential gear and the differential housing;

(8) After the ring welding is completed, the differential gear is ground to make the differential gear meet the accuracy standard of 3-7 in GB/T 10095.1-2008/ISO 1328-1:1995.
A welding process for a differential assembly according to claim 1, wherein in step (4), after filling the welding wire, the contact faces of the differential case and the differential gear are evenly divided into 3 Spot welding at 8 points.
[Correct according to Rule 91 19.04.2019]
A welding process for a differential assembly according to claim 2, wherein in step (5), the differential housing and the differential gear are clamped by a clamp, and the laser beam is used to surround the weld. In one turn, the iron-nickel alloy wire is dissolved, and the differential gear and the differential case are welded and fixed.
[Correct according to Rule 91 19.04.2019]
A welding process for a differential assembly according to claim 3, wherein in the steps (5) and (6), the position of the welding is in the axial direction of the differential gear and the differential case Contact surfaces.
A welding process for a differential assembly according to claim 4, wherein said differential housing and differential gear weld are located at the end of the stepped shaft bore having a small diameter.
A welding process for a differential assembly according to claim 5, wherein the weld depth of the differential housing and the differential gear weld is 5 ± 0.5 mm.
A welding process for a differential assembly according to claim 3, wherein in the steps (5) and (6), the position of the welding is located in the radial direction of the differential gear and the differential case. Contact surfaces.
A welding process for a differential assembly according to claim 7, wherein a weld depth of said gear to the housing weld is 6 ± 0.5 mm.