CN111958178B

CN111958178B - Method for manufacturing wheel rim

Info

Publication number: CN111958178B
Application number: CN202010648165.5A
Authority: CN
Inventors: 刘梦洁
Original assignee: Dongfeng Motor Chassis Systems Co Ltd
Current assignee: Dongfeng Motor Chassis Systems Co Ltd
Priority date: 2020-07-07
Filing date: 2020-07-07
Publication date: 2022-01-18
Anticipated expiration: 2040-07-07
Also published as: CN111958178A

Abstract

The invention relates to a method for manufacturing a wheel rim, wherein the raw material of the wheel rim is a hot rolled steel coil; the manufacturing method comprises the following steps: (a) cutting the hot-rolled steel coil into rim blanks; (b) performing cold roll forming treatment on the cut hot rolled steel coil; (c) shearing the cold-roll formed hot-rolled steel coil into a long strip with the single-multiple length of the rim; (d) and carrying out edge rolling, butt welding and fine expansion treatment on the strip material to obtain a finished rim. The invention obviously improves the production efficiency, reduces the rejection rate and the production cost, and reduces the drawing at the circular arc part of the rim and the residual stress of the finished rim; the invention has wide application range, can manufacture a section type rim with more complex shape, for example, a plurality of reinforcing ribs are added, thereby improving the strength of the wheel and realizing further light weight; the finished rim manufactured by the method has the advantages of accurate size, low residual stress, small thinning amount and high strength, and the fatigue life of the rim is effectively prolonged.

Description

Method for manufacturing wheel rim

Technical Field

The invention belongs to the technical field of automobile manufacturing, and particularly relates to a method for manufacturing a wheel rim.

Background

The rim is an intermediate member that holds the tire and connects the tire and the axle. The rim has the functions of bearing the weight of the vehicle, transmitting power, supporting tires and the like, and is used as a rotary motion part, and the rim has certain rigidity and must meet the technical conditions of light weight, fatigue resistance, dynamic balance and the like.

As shown in fig. 1, the conventional production process of the rolling rim is as follows: plate blanking, edge rolling, butt welding, slag scraping, polishing, flaring, three-time rolling and fine expanding. The traditional process is that a cylinder is welded and then is subjected to three-time rolling forming, three-time positioning is needed, and inaccurate positioning is easily caused by multiple changes of positioning references; moreover, the arc section part is always in repeated stretching deformation due to the working processes of positioning, material distribution and the like in the three-time rolling process, so that the arc section is thinned by more than 8%.

In summary, the conventional process of the roll-type rim has some problems: (1) the size of the formed rim is not accurate, and the size of the part matched with the spoke is difficult to meet the requirement of a product drawing, so that the outer diameter of the spoke is frequently reworked; (2) uneven material distribution is easily caused in the production process of the rim, namely, the materials on two sides of the rim are inconsistent, so that scrapping is caused; (3) the rim thinning amount reaches about 10 percent, and the fatigue life of a product is influenced; (4) the residual stress after the rim is formed is large, and the fatigue life of a product is influenced; (5) the rim production is the one-by-one pass production of a single wheel, and the production efficiency is low.

Disclosure of Invention

The invention provides a wheel rim manufacturing method aiming at the technical problems in the prior art, and solves at least one of the problems of inaccurate size of a finished product rim, uneven material distribution, high rejection rate, excessive rim thinning amount, high residual stress after rim molding, low production efficiency and the like in the traditional production process of a rolling type rim.

The technical scheme for solving the technical problems is as follows:

a wheel rim manufacturing method, the raw material of the wheel rim is a hot rolled steel coil; the manufacturing method comprises the following steps: (a) cutting the hot-rolled steel coil into rim blanks; (b) performing cold roll forming treatment on the cut hot rolled steel coil; (c) shearing the cold-roll formed hot-rolled steel coil into a long strip with the single-multiple length of the rim; (d) and carrying out edge rolling, butt welding and fine expansion treatment on the strip material to obtain a finished rim.

On the basis of the technical scheme, the invention can be further improved as follows.

Further, in the step (d), pulse flash butt welding is adopted for butt welding, and the parameters are as follows: preheating distance of 4mm, flash distance of 6mm, upsetting distance of 6mm, charged upsetting time of 0.5s, preheating current of 450A and upsetting pressure of 6.5 MPa.

Further, in the step (d), the rim is subjected to slag scraping and polishing treatment after butt welding.

Further, the hot rolled steel coil is bent through a cold bending forming die to obtain the section of the rolling tubeless rim.

Furthermore, all parts of the hot rolled steel coil are in smooth transition after being bent, so that the surface of the rim is free from scratches and pits.

Further, the thinning amount of the hot-rolled steel coil after being bent is not more than 4%.

Further, the expansion amount of 10-20 mm is ensured during fine expansion, so that the size, the end face and the jumping amount of the expanded bead seat are ensured.

The invention has the beneficial effects that: the invention obviously improves the production efficiency, reduces the rejection rate and the production cost, and reduces the drawing at the circular arc part of the rim and the residual stress of the finished rim; the invention has wide application range, can manufacture a section type rim with more complex shape, for example, a plurality of reinforcing ribs are added, thereby improving the strength of the wheel and realizing further light weight; the finished rim manufactured by the method has the advantages of accurate size, low residual stress, small thinning amount and high strength, and the fatigue life of the rim is effectively prolonged.

Drawings

FIG. 1 is a flow chart of a conventional production process of a rolling rim;

FIG. 2 is a flow chart of a manufacturing method according to an embodiment of the invention.

Detailed Description

The principles and features of this invention are described below in conjunction with the following drawings, which are set forth by way of illustration only and are not intended to limit the scope of the invention.

A wheel rim manufacturing method, the raw material of the wheel rim is a hot rolled steel coil; the manufacturing method comprises the following steps: and (3) cutting, cold roll forming, cutting, rounding, butt welding and fine expansion treatment are carried out on the hot rolled steel coil to obtain a finished rim.

Example 1

As shown in fig. 2, the method for manufacturing a wheel rim according to the present embodiment includes the following steps:

(a) cutting the hot-rolled steel coil into rim blanks: cutting the coiled plate into 5 small coils to ensure that the small coils are neat and cannot have tower shapes; calculating the blanking width size of the raw material according to the final size of the product, wherein the width tolerance is within +/-0.2 mm;

(b) performing cold roll forming treatment on the slit hot rolled steel coil: firstly, flattening the small roll, and then bending the small roll through a cold bending forming die to obtain a section of the rolling type tubeless finished rim; smooth transition of all parts after bending ensures that the surface of the rim is not scratched, pressed pits and the like, and the thinning amount after bending is not more than 4 percent;

the cold roll forming of the hot rolled steel coil is gradually changed into a wheel rim section shape through a plurality of cold roll tools, the wheel rim section shape is connected, the installation position of each forming tool is accurate, the straight section does not have the thinning and thickening phenomena except that the arc section is slightly thinned (not more than 4 percent thinning), and therefore the dimensional precision is better than that of the wheel rim produced by the traditional process, and the residual stress and the thinning amount are lower than those of the wheel rim produced by the traditional process;

(c) shearing the cold-roll formed hot-rolled steel coil into a long strip material with the length of a single multiple length of the rim, and ensuring that the two cut ends have no phenomena of inclination cutting and deformation and no burrs; calculating to obtain the blanking length size according to the final size of the product;

(d) firstly, rolling the strip material cut into a single multiple length, ensuring that the two ends after rolling are in good butt joint, and avoiding the phenomena of front and back teeth, upper and lower teeth and the like;

and then, welding by adopting pulse flash butt welding, wherein the parameters are as follows: preheating distance of 4mm, flashing distance of 6mm, upsetting distance of 6mm, charged upsetting time of 0.5s, preheating current of 450A and upsetting pressure of 6.5 MPa; the pulse flash butt welding is adopted, so that the burning distance is short, the burning time is short, the metal softening of a heat affected zone is small, the welding stress is small, the welding effect and efficiency can be improved, and meanwhile, the residual stress of a finished rim can be obviously reduced, and in addition, the pulse flash butt welding is adopted, so that the production and processing cost of the rim can be reduced;

then, slag scraping and polishing are carried out to improve the quality of the rim;

finally, performing fine expansion treatment to obtain a finished rim; and ensuring the expansion amount of 10-20 mm during fine expansion so as to ensure the size, the end face and the jumping quantity of the expanded bead seat.

The cold roll forming is a new process and a new technology for forming metal plates with material saving, energy saving and high efficiency. By utilizing the cold roll forming process, not only can high-quality section steel products be produced, but also the product development period can be shortened and the production efficiency can be improved.

The flash welding is an economic and high-efficiency welding method, mainly utilizes a butt welding machine to make two ends of metal contact, and utilizes low-voltage strong current to make the metal be heated to a certain temperature and softened, then makes axial pressure upsetting so as to form butt welding joint.

Comparative example 1

As shown in fig. 1, the rolling rim is manufactured by using a conventional production process: plate blanking, edge rolling, butt welding, slag scraping, polishing, flaring, three-time rolling and fine expanding.

And fatigue tests were performed on the rims manufactured in example 1 and comparative example 1, and the fatigue test results were obtained as shown in table 1 below.

TABLE 1

Referring to table 1, it can be seen from the comparison of the test data of example 1 and comparative example 1 that the solution of example 1 is significantly better than comparative example 1 in terms of mechanical properties, strength and fatigue life. Therefore, the technical scheme of the invention has a technical effect obviously superior to that of the comparative example 1, and the rim manufactured by the technical scheme of the invention has obvious improvement in the aspects of strength and fatigue life. In addition, the production efficiency of example 1 is much higher than that of example 1.

The manufacturing method provided by the invention has the advantages that the production efficiency is obviously improved, the rejection rate and the production cost are reduced, and the thinning of the circular arc part of the rim and the residual stress of the finished rim are reduced; the manufacturing method is wide in application range, and can manufacture the section type rim with more complex shape, for example, a plurality of reinforcing ribs are added, so that the strength of the wheel is improved, and meanwhile, the further light weight is realized; the finished rim manufactured by the manufacturing method has the advantages of accurate size, low residual stress, small thinning amount and high strength, effectively prolongs the fatigue life of the rim, and can effectively solve the technical problems in the prior art.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.

Claims

1. The manufacturing method of the wheel rim is characterized in that the raw material of the wheel rim is a hot rolled steel coil; the manufacturing method comprises the following steps: (a) cutting the hot-rolled steel coil into rim blanks; (b) performing cold-bending forming treatment on the cut hot-rolled steel coil through a cold-bending forming die to obtain a section of the rolling inner tube-free rim; (c) shearing the cold-roll formed hot-rolled steel coil into a long strip with the single-multiple length of the rim; (d) and carrying out edge rolling, butt welding and fine expansion treatment on the strip material to obtain a finished rim.

2. The manufacturing method according to claim 1, wherein in the step (d), the butt welding is performed by pulse flash butt welding, and the parameters are as follows: preheating distance of 4mm, flash distance of 6mm, upsetting distance of 6mm, charged upsetting time of 0.5s, preheating current of 450A and upsetting pressure of 6.5 MPa.

3. The manufacturing method according to claim 1, wherein in the step (d), the rim is subjected to a scraping and grinding treatment after butt welding.

4. The manufacturing method according to claim 1 or 2, wherein the hot rolled steel coil is bent by a plurality of cold-bending forming dies to obtain a roll-type tubeless rim section.

5. The manufacturing method according to claim 4, wherein the hot rolled steel coil is smoothly transited at all parts after being bent so as to ensure that the surface of the rim is free from scratches and indentation.

6. The manufacturing method according to claim 4, wherein the hot rolled steel coil is reduced by not more than 4% after being bent.

7. The manufacturing method according to claim 1 or 2, wherein an expansion amount of 10 to 20mm is secured at the time of the finish expansion to secure a bead seat size after the expansion and an end face and a run-up amount.