JPS5930496A - Production of al alloy wheel - Google Patents

Abstract

PURPOSE:To manufacture a wheel with high productivity and at a low cost while maintaining satisfactorily the required strength, by heating a rim consisting of a heat treated Al alloy then fitting a disc made of the same material having the outside diameter slightly larger than the inside diameter of the rim before heating to said rim, welding both over the entire circumference, and subjecting the welded wheel to a T6 heat treatment. CONSTITUTION:A hollow pingot 14 made of, for example, A6061 Al alloy is passed successively in a heating furnace 15, a roll working part 16 and a machining part 17 and a prescribed rim 11 is manufactured in a stage I . On the other hand, an ingot 18 of the same material as the material of the rim 11 is passed in a heating part 19 and a forging part 20 to form a disc having a prescribed shape, whereafter the disc is machined 21 and a disc 12 having the outside diameter larger by 0.5-2mm. than the inside diameter of the rim 11 is manufactured, in a stage II. The rim 11 is heated to 50-200 deg.C in a fitting part 24 in a stage III, whereafter the outside circumference of the disc 12 is fitted into the inside circumference of the rim 11, and both fitted parts are welded over the entire circumference by MIG welding in a welding part 25. The resulted wheel shape object is subjected to hardening-tempering by a so-called T6 heat treatment method, whereby an intended Al alloy wheel 13 is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing an automobile wheel made of an At alloy, and in particular, a method for separately adjusting the raw side of the wheel for molding the lino part and for molding the dennisc part. After these two are fitted and welded, a predetermined heat treatment is performed.

Wheels manufactured by @ are generally used for wheels such as l-racks, Nodas, and passenger cars, but they maintain a certain level of strength, reduce the unsprung weight of the car, are easy to handle, and are aesthetically pleasing. Wheels made of At alloy (hereinafter simply referred to as "At wheels") have become popular due to their improved performance.

In particular, the so-called 1501)C-shaped wheel rims for Chee-breath tires on Tonkatsu buses are becoming popular17.

By the way, when manufacturing such A-7 alloy wheels with a 15° DC lino shape (hereinafter simply referred to as "wheels"), they are usually formed from a single piece of material from the viewpoint of maintaining strength. For this formation, the bare side is usually forged 17 first. After forming the J-shaped member, the L1 shape of the member is further processed by forging or rolling.
Shape, ie, mold the rim part.

), then mechanical processing such as perforation) and window drilling are performed on the disc part. FIGS. 1 to 4 show an example of such a manufacturing method, in which a bit 1 is hot-forged to form a dish-shaped forged product 2, and further hot-forged to form a cup-shaped member 3. In the cup-shaped member 3, a cylindrical portion 4 serving as the lino-forming portion of the wheel, a bottom side 5 of the outer disk forming portion and L2 are integrally formed.

When molding the lino part, the cylindrical part 4 of the cup-shaped member 3 is placed on the inner roll 6, which has a protrusion 6a corresponding to the connecting curved surface between the bottom side 5 and the cylindrical part 4. The outer roll 8 is press-welded (2).The disk portion 5 thus formed and integrally formed is then subjected to the predetermined machining as described above to complete the wheel.

By the way, what about wheels based on this forging method? !
In the manufacturing method, there are problems as shown in (1) to (4).

■ Even if the diameter of the target wheel is slightly increased (fv), a forging press forming machine several times the size will be prepared, and tl i,l: will not be 7, so h( Reserve costs will increase.

■ If the lino/diameter or lino/IJ of the target wheel differs, a new mold will have to be prepared each time), which will increase the mold cost.

■ Because of the hot forging method, it is difficult to achieve high accuracy.
Furthermore, since the forged material is cup-shaped, the salinity decreases unevenly during hot working. In particular, in the cup-shaped member 3, the boundary between the bottom side 5 and the cylindrical portion 4 and the peripheral surface of the cylindrical portion 4 tend to have non-uniform properties.

■ As mentioned above, the dimensional accuracy of the cup-shaped part 3, which is a hot forged product, is not constant, so cutting is required at the material stage, and even after forming, it is often useless unless it is cut. . Therefore, the material yield in the forming stage is about 50%, and combined with the problems (i) and (2) above, the manufacturing cost of wheels is rising, and
ft i, I, decreases. Therefore, it is particularly unsuitable for low M production.

This tendency becomes more pronounced as the wheels become larger, and a prompt solution was desired.

The present inventors focused on these circumstances and developed a method that can manufacture wheels at high productivity and at low cost while maintaining sufficient required strength without using a large-scale forging method such as the upper rudder. After extensive research, we finally arrived at a manufacturing method that fully meets expectations, and we are now offering it here.

However, the manufacturing method of such a wheel is heat treatment P1j
After heating a rim made of At-based At alloy (for example, A'6000 series, A-7N 01 series) to 50 to 200°C, the outer diameter Th is 5 to 2 times larger than the inner diameter of the rim before heating. The gist is that a disk made of the same material as the rim is fitted into the rim, and both are welded all around, 2 and then heat treated.

Hereinafter, the present invention will be explained in detail based on the drawings. However, the drawings show an example of a specific method, and the present invention is not limited to these illustrated examples, and other methods may be used in keeping with the spirit of the above and below. It is also possible to carry out the process in the same manner as described above, or by partially changing n'tMl.

FIG. 1.
The wheels 13 are then joined together to produce an integrated wheel 13.

In the step (1), for example, an alloy hollow ingot 14 of A 6061 A is placed in the heating section 15, and the
Heat at 30°C for a specified time. The sufficiently heated ingot 14 is sent to the processing section 16, where it undergoes ring processing. IrJ after processing - Ingot 1
Processing start temperature of 4 is approximately 400°C 1 processing end temperature is approximately 3
It is desirable to set the temperature so that the temperature is 000C, and to run the Twickle Taino for about 5 minutes in one bath. Culling roll processing in this way makes it possible to form a seamless rim, which stabilizes the strength of the rim and allows it to be formed into the shape of the defect g( can be freely controlled.Therefore, it is possible to effectively increase the strength of the J section with small bare side protrusions.In dimension ring roll processing, the crotch of the ring roll mold can be controlled at ℃ Since the same mold can be used for molding rims with different diameters, mold costs are reduced and it is economical.
The formed rim is introduced into a cutting section 17, and the inner circumferential surface that becomes a fitting surface when fitting with a disk, which will be described later, is cut to obtain a predetermined rim 11.

Next, step 1- of (11) is the process of manufacturing the disk J2 as described above, of which (■) in (II) indicates the process on Kinomio's side, and ■d indicates the process of other embodiments. That is, (1) ■J: For the culm, A, 606 ] A 1. The alloy ingot 18 is formed into a disk of a predetermined shape through a heating section 19 and a forging section 20 (after 7), a cutting section 21 cuts the maximum outer circumferential surface that will become the fitting part when fitting with the two bases 11. is cut to obtain the desired disc 12. During cutting, the maximum outer circumferential diameter must be 0.5 to 2 larger than the fitted inner circumferential diameter of the rim J1, as will be described later. Next, to explain the process (2), which is another example process,
After cold spinning is performed to form a disk into a predetermined shape 7, a predetermined disk 12 is obtained by cutting in the same manner as in the cutting section 21 described above at a cutting section 21'. In the example process of (1). Since the forging scale is silent, the spinning process is not performed cold in the example process of (Mataka).
Both formability and productivity are good.

In this way, person 1] and disk 12 are both obtained (in
) to the fitting section 24 of the process. Before fitting, the rim is heated to 50 to 200°C in advance. IJ below 50°C
The A diameter is large and difficult to fit with the disc, and at temperatures above 200°C there is a concern that the strength of the material will decrease, and furthermore, the crystal grains on the surface of the material may be hardened. This is because the strength after heat treatment cannot be expected.

On the other hand, for the discs to be fitted, as mentioned above, the fitting distance with the rim is set to 0.5 to 2 inches. Integration in terms of wheel strength cannot be expected, and it is difficult to pass the wheel strength test described below, and if the number of wheels exceeds 2, the initial stress on the mating surfaces of the rim and disc after cooling becomes too high. This is because the strength of the wheel is reduced.

In this way, the rim and the disc are fitted together by a shrink-fitting operation that sets the optimum temperature range and suitable fitting distance. However, the fitting operation according to the present invention can solve this problem.

In addition, since the fitted state is very good, the effects of prescribed welding and heat treatment as described below can be synergistically enhanced, making it easy to obtain the required hole strength. I can do it. It is of course possible to perform press fitting while heating the ω1 lino, and this method is considered suitable when a high molding speed IW is required.

Now, M-G welding is performed on the welded portion 25 of the shrink-fitted wheel. For welding, use an A4043 series welding rod, for example, and perform single layer welding around the entire circumference.

However, there are no particular restrictions on the welding material or welding method. In the present invention, the lid and disc are fitted together, welded, and integrated in this way, so compared to the conventional forging method in which the lid and disc are manufactured as one piece from the beginning, the lid and disc are integrated. It is possible to reduce the element side amount separately, which is economical. 2. After welding, the integrated rim and disk are sent to the heat treatment section 25, where they are baked by the so-called 1゛6 heat treatment method. Perform heating and tempering. As a result, mechanical properties, particularly stiffness and tensile strength, can be greatly improved, and reduction in strength due to welding can be minimized.

The heat-treated integrated product is then sent to the machining section 26, where the entire rim and disc parts are cut and holes, such as holes, bolt holes, etc., are processed to complete the product wheel J3, depending on the purpose of the wheel. .

Regarding this product wheel 13, Ministry of Transport Technical Standards (JWL)
-T), the results shown in the first rock below were obtained, and the strength of the wheel produced by the manufacturing method of the present invention is fd knee J22 standard 1 min i'. I could confirm the voice.

Table 1: Manufacturing method of the present invention (Since ・: was configured as shown below,
Wheel and 1. 1. Keep the required strength at 1 minute. , taA
It has now become possible to economically and efficiently produce wheels made of ,/-alloy for 111 applications. In particular, the production of tires and wheels for large vehicles such as buses and trucks has an extremely large amount of benefits.

[Brief explanation of the drawing]

1 to 264 are explanatory diagrams illustrating the manufacturing process of a conventional At alloy wheel, and FIG. 5 is an explanatory diagram showing the entire manufacturing process of the present invention. IJ...Rim 12...Disk 13...Wheel 24...Fitting part 25...Welding part 26...Heat treatment part 27...Mechanical machining E part exit Applicant: Hisashi Ueki, Patent Attorney, Kobe Steel, Ltd.: ,, ′, +,,,,,,
. (Figure 1, Figure 2, Figure 4, 1 procedural amendment) September 17, 1986 Kazuo Wakasugi, Commissioner of the Japan Patent Office Chief Examiner of the Japan Patent Office Tokuffr'l
``? Examining Palace 1, Indication of the case 2, Name of invention or device Manufacturing method for Ae alloy wheels 3, Person responsible for assistance 2 (relationship with '1 (Special revision 1111 Applicant 1)
1゛ Address: 3-18-4 Wakihama-cho, Chuo-ku, Kobe City
, Acting agent 530 Postal Kaori Address 2-chome Dojima, Kita-ku, Osaka [÷13-7 Shinko Building 6, Supplement 1]
(1) In the specification page 10, table 1, the column ``RJ WL-T standard water e μ size (8,25X22.5)'' and [
r2 at the intersection of the column "Fatigue strength of rotating surface". ol
zK9J to r2 I) 12) Revised 7Et to t9J.

Claims (1)

[Claims] (1) After heating the heat treatment system A4 alloy lino to 50 to 200°C, 0.0 mm from the inner diameter of the lino before heating.
A method for manufacturing an At alloy wheel, which comprises fitting a disc made of aluminum having an outer diameter of 5 to 2 times larger into the rim, welding the two together around the entire circumference, and then subjecting them to T6 heat treatment.