JPS606231A - Production of wheel rim for vehicle - Google Patents

Abstract

PURPOSE:To obtain a rim having good balancing accurcy without variance in wall thickness by rolling a blank pipe in a diametral direction by roll forming to have a prescribed wall thickness. CONSTITUTION:An upper roll 3 under rotation is brought into press contact with a blank pipe and is rotated together with a lower roll 2 to roll the blank pipe in a diametral direction and to expand the pipe toward the diametral outside while making the wall thickness uniform, by which the 1st cylindrical body 11 provided with a cylidrical part 11a, large diameter part 11b, 11b and tapered parts 11c, 11c having prescribed sizes is obtd. The body 1 is then set in a press die 12 and is pressed with right and left punches 13, 13 to size a recess 52, large diameter parts 21b, 21b and large diameter parts 21c, 21c at the outside end, by which the 2nd cylindrical body 21 having a prescribed size is obtd. The lower roll is then set in the body 21 and while the upper roll is rotated from the outside, said roll is brought into contact with the cylindrical body from above. A rim consisting of a bead receiving part and the recess 52 is thus obtd.

Description

[Detailed description of the invention] The present invention relates to a method for manufacturing a vehicle wheel rim.

A vehicle wheel is composed of a rim to which a tire is attached, and a disc formed on the inner circumferential side of the rim and attached to a hub of an axle.Such a rim is conventionally manufactured by spatula drawing or roll forming. In spatula drawing, a wheel-shaped roll mold is set inside a drawn raw tube with a diameter that is small, and the outer rollers and other parts are pressed together to form the product. This results in variations in wall thickness, poor rim balance accuracy, and wrinkles occur on the inner surface during drawing, requiring a separate puffing process to remove them. In addition, in the roll forming, one of the upper and lower rolls, for example, the lower roll, is drawn and placed inside the raw pipe, and the raw pipe is expanded in the radial direction while being rolled by the upper roll and the lower roll to form the rim. However, since this method simply rolls the raw pipe with upper and lower rolls, it is difficult to obtain precision in rim roundness and cylindricity, and there may be variations in diameter or wall thickness. There are problems such as not being able to prevent variations in the results.

The present invention has been devised to solve the above-mentioned problems, and the purpose of the present invention is to equalize the wall thickness and achieve dimensional accuracy even when using raw pipes with uneven wall thickness. The purpose of the present invention is to provide a method for manufacturing wheel rims with high balance accuracy and excellent production efficiency.

In order to achieve the above object, the present invention includes a roll forming process in which a lower roll is inserted into a tubular workpiece and a corresponding upper roll rolls the workpiece in the radial direction while expanding the workpiece, and a press capable of regulating the outer diameter. A press forming process in which the workpiece obtained by the roll forming is set in a mold and the entire outer diameter is sized with a punch from inside the workpiece, and a lower roll and a corresponding upper roll are inserted into the workpiece obtained by the press forming. The method is characterized by a roll forming process in which the bead receiver is formed on the workpiece.

A preferred embodiment of the present invention will be described below with reference to the accompanying drawings.

1 to 4 are cross-sectional side views sequentially showing the manufacturing process of the present invention.

1 is an extruded aluminum alloy base tube, first the base tube 1
Set the lower roll 2 inside, and then insert the upper roll 3 from the outside of the raw pipe 1.
Roll forming is performed by rotating and press-welding.

The lower roll 2 has left and right divided bodies 4 that are rotatably supported.
. It is formed in the portion 4c.

The upper roll 3 includes a body portion 3a corresponding to the lower roll 2, small diameter portions 3b, 3b, and tapered portions 3c, 3c.

While rotating the upper roll 3, the raw pipe 1 is pressed against the raw pipe 1.
is rotated together with the lower roll 2, and the raw pipe 1 is rolled in the radial direction by the upper roll 3 and the lower roll 2, and expanded radially outward while equalizing the wall thickness, to form a large diameter portion of the body 11a1 having a predetermined size. 11b,
11b, a tapered portion 11c, and a first cylindrical body 11 including llc.
Get it.

Next, the first cylindrical body 11 is set in the press die 12, and press molding is performed using the left and right punches 13 and 13.

The press chamber 12 consists of an upper mold 14 and a lower mold 15, and the press mold 12 has a small diameter hole 12a having an inner diameter equal to the outer diameter of the recess 52 of the rim 51, and a small diameter hole 1 as shown in FIG.
2a and a large diameter hole 12b having an inner diameter corresponding to the outer diameter dimension of the tire seat 53 of the rim 51;
The outer end large-diameter hole portion 12c is formed on both sides of the rim 51 and has an inner diameter corresponding to the outer diameter dimension of the ear portion 54 of the rim 51.

The left and right punches 13.13 each have a small diameter part 13a1, a large diameter part 13b1, and an outer large diameter part 13 corresponding to the press die 12.
c'ff: Prepare.

The left and right punches 13.13 are pushed from the left and right into the first cylinder 11 set in the press mold 12, and the first cylinder 11 is formed with a recess 52 and a large diameter part 21b.

The large diameter outer end portions 21c and 21c of 21b1 are sized to obtain the second cylindrical body 21 having a predetermined size.

Next, as shown in FIG.
The upper roll 24 is pressed from the outside of the cylinder 21 while rotating, and the recess 5 is formed by the molded parts 23a and 24a of each roll 23.24.
2. The large diameter portions 21b1 on both sides are formed into the outer end large diameter portions 21ct into bead receiving portions 55.

The bead receiving portion 55 is connected to the tire seat 53 as shown in FIG.
, a hang portion 56 formed to bulge on the tire seat 53, an ear portion 54 that stands up radially outward from the outer end of the tire seat 53, and a curl portion 57 that curves the outer edge of the ear portion 54 inwardly. In this way, a rim 51 consisting of a bead receiving part 55 and the recessed part 52 is obtained.

In the embodiment, the thickness t1 of the bottom surface of the recess 52 is 3 and 6.
m+, the thickness t2 of the side surface of the recess 51 is 3.2 rrv
n, the thickness t3 of the ear portion 54 was molded to 3.

A disk 61 is attached to an appropriate location on the inner circumferential surface of the rim 51, for example, on the inner circumferential surface of the recess 52, to obtain a wheel 62.

In addition, 63 in the drawing is a hole for an air valve bored in the four parts 52.

Therefore, according to the present invention, the raw pipe 1 is first rolled in the radial direction by roll forming to obtain a predetermined wall thickness, so even if the raw pipe 1 with uneven wall thickness is used, there is no variation in wall thickness and the balance accuracy is maintained. A high rim 51 can be obtained.

In addition, since the first cylindrical body 11'ff, which is formed by rolling the raw tube 1 and forming it to a predetermined wall thickness, is sized by nibless molding, it is possible to obtain the rim 51 with high dimensional accuracy and high roundness, cylindricity, etc. .

In addition, since the diameter of the thick-walled raw tube 1 is expanded in each process of roll forming, press forming, and roll forming, there is no risk of wrinkles occurring, and therefore the puffing process is not performed as in the conventional method. It is possible to obtain a rim 51 with a good surface roughness without the need for molding, and the quality of the finished surface can be further improved by alumite treatment or the like after molding.

Furthermore, as shown in FIG. 7 showing a rim 51 obtained by the present invention and FIG. 8 showing a rim T1 obtained by conventional drawing, in the past, a large-diameter thin-walled blank tube 12 with approximately the same diameter as the rim diameter was used. In contrast, according to the present invention, since the raw tube 1 is first rolled by roll forming, a product can be obtained from the raw tube 1 with a diameter smaller than the rim diameter, and the material has a good sharpness and the material cost is reduced. The top is also extremely advantageous.

As is clear from the above explanation, according to the present invention, it is possible to use a raw tube with a diameter smaller than the rim diameter, and even when a raw tube with uneven wall thickness is used, it is possible to achieve balance accuracy with equalized wall thickness, It exhibits many excellent effects, such as being able to obtain a rim with high roundness and dimensional accuracy, and being able to improve rim production efficiency and contribute to cost reduction.

[Brief explanation of the drawing]

1 to 4 are sectional side views showing the manufacturing process of the present invention in order, FIG. 5 is a view taken along the V arrow in FIG. 3, FIG. 6 is a half sectional view of the rim, and FIG. FIG. 8 is a cross-sectional view of a portion of a rim obtained by a conventional method. In addition, in the drawing, 1 is the raw pipe, 2 is the lower roll, 3 is the upper roll, 12
13 is a press mold, 13 is a punch, 23 is a lower roll, 24 is an upper roll, 51 is a rim, 61 is a disc, and 62 is a wheel. Patent Applicant Honda Motor Co., Ltd. Agent Patent Attorney Part 2 1) Production Department Patent Attorney Kuni Ohashi Production Patent Attorney Yu Koyama Figure 7 Figure 8 Procedural Amendment (Voluntary) 1. Indication of the Case Tokushu Akira 58-114044 No. 2, Title of the invention Method for manufacturing vehicle wheel rims 3, Relationship with the person making the amendment Patent applicant (532) Honda Motor Co., Ltd. 4, Agent 5 Date of amendment order Spontaneous

Claims (1)

[Claims] A roll forming process in which a lower roll is inserted into a tubular workpiece and a corresponding upper roll is used to roll and expand the workpiece in the radial direction, and the outer diameter of the workpiece is controlled by the roll forming process in a press mold. A press forming process in which a workpiece is set and the outer diameter is sized with a punch from inside the workpiece, and a lower roll inserted into the workpiece obtained by the press forming and a corresponding upper roll are used to form a part of the workpiece. A method for manufacturing a vehicle wheel rim, which comprises a roll forming process.