JPS6049050B2 - How to shape a ring with cuts - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for shaping a ring having a cut in a certain place in the circumferential direction.
The present invention also relates to a ring shaping method that allows the ends of the cuts to be brought into pressure contact so that the gap between the cuts becomes zero.

An example of a ring having a cut is a side ring for an automobile wheel.

As shown in FIGS. 1 to 3, the side ring 1 is bonded to an automobile wheel rim 2 and attached to a heat section 4 of a tire 3.
However, since it is necessary to temporarily expand the diameter when mounting the rim 2 over the gutter portion 5, there are cuts 6 in the circumferential direction. When the side ring 1 is attached to the rim 2, if the flat surface 7 of the side ring 1 is undulated or twisted, the side ring 1 will locally contact the rim 2, causing stress concentration and causing cracks in the rim 2. Therefore, the flat portion 7 of the side ring 1 must be in surface contact with the rim 2, and the flat portion 7 is required to have high planar accuracy. Also side ring 1
When the side ring 1 is attached to the rim 2, there is a certain gap between the cuts 6 of the side ring 1, and the air pressure of the tire 3 compresses the heated part of the side ring 1 in the radial direction, thereby separating the rim 2 and the side ring 1. In order to ensure that the side rings 1 and 2 are in close contact with each other, when the side ring 1 is alone and free, it elastically cuts into the cut 6.
must be in close contact. In order to satisfy such requirements for dimensional accuracy and zero clearance, side rings have conventionally been formed as shown in FIG. 4 or 5.

That is, the side ring is formed as shown in Fig. 4.
After being wound with a pending machine 8, it is once welded 9, shaped from the inside with a mold 10, and after cutting the welded part 9, the cut part is processed to make the gap zero using a press 11 or a roll, or As shown in FIG. 5, after being rolled up using a pending machine 8, it was shrunk and shaped from the outside using a mold 12 to make the cuts 6 with zero gaps. However, with the stretching method from the inside as shown in Fig. 4, the number of steps is large, the processing cost is high, and the amount of scrap generated during welding and cutting is 100% of the material. This results in a large amount of energy used during welding, and the roundness is poor due to distortion during shaping and gap correction with split molds.
There was a problem in that the diameter varied by about 2Tf0TL.

In addition, in the method of shaping while shrinking from the outside as shown in Figure 5,
The number of steps is small, but 1% before and after shaping to reduce the gap.
It is necessary to set the above-mentioned shrinkage allowance, which results in wasted material, and if the plate thickness of the member is thin, a counterbore 13 as shown in Fig. 6 will occur, resulting in a defective product. Because of this, there was a problem that it became somewhat flower-shaped. The present invention
In order to solve the above problems, we aim to achieve the flatness of the flat part of the link with cuts, with the minimum number of processes, without wasting material, without creating counterboring, and with the minimum number of steps. The purpose is to provide a shaping method that reduces the gap to zero.

A method for shaping a ring having a cut according to the first aspect of the present invention that meets this purpose is to correct the waviness and twist of the ring by press-fitting the ring with the cut into a small diameter die and pressing the ring in the axial direction. The method for shaping a ring having a cut according to the second aspect of the present invention is to press-fit a ring with a cut into a die with a small diameter and press the ring to form a undulation of the ring. In addition to correcting the torsion, the inner periphery of the ring is subjected to greater pressure strain than the outer periphery.

In the following, the method of the present invention will be explained using an automobile wheel side ring as an example of the ring 3 having cuts.

FIG. 7 is an enlarged cross-sectional view of the automobile side ring 1, and 7 is a flat portion that requires the above-mentioned flatness accuracy, and the outer peripheral side of the flat portion 7 extends in a curve 3. A flange portion 14 is formed, and the inner peripheral side thereof is bent at a substantially right angle and extends to form a bead portion 15.

Further, the bead portion 15 has a hook portion 16 41 at a position slightly away from the flat portion 7, one surface of which constitutes a part of the flat portion 7 and protrudes in the ring inner circumferential direction. The line 17-17 is an imaginary line parallel to the axis passing through the centroid of the cross section or its vicinity, and the side a from it indicates the outer circumference side of the ring, and the side b thereof indicates the inner circumference side of the ring. As shown in FIG.
Place it on top.

The die 18 is movable up and down, and a punch 19 is provided above the punch 19 by being attached to a plate 20 with a punch mount 7, so that the punch 19 is lowered and pressed against the die 18. A die 21 for a tightening shaping mold is fixedly provided at a position on the outer peripheral side when the die 18 is lowered. The die 21 has a diameter of 0 from the outside diameter of the side ring 1 before shaping.
．． It has a compression part 22 with an inner diameter that is 3 to 0.4% smaller in diameter, and a sliding part 23 that tapers upward by 5 to 1.5 degrees is provided on the upper part of the compression part 22. The diameter difference between the compression part 22 and the side ring 1 is necessary to finish the cross-sectional shape and diameter with high precision, and the angle of the sliding part 23 is as follows.
This is designed to reduce the pressing force when pressing and to pressurize easily. Next, as shown in FIG. 9, the punch 19 is lowered together with the punch mounting plate 20, and after contacting the side ring 1, the side ring 1 and the die 18 are further lowered, and the side ring 1 is attached to the punch 19 and the die. 21, push it in until it is strongly pressed by the die 18.

During this lowering process, when the side ring 1 is pushed from the sliding part 23 into the compression part 22, the side ring 1
A compressive force is applied in the circumferential direction to reduce the gap between the cuts 6 to zero, and the diameter and cross-sectional shape are accurately finished. Further, when the side ring 1 is pressed between the punch 19 and the ties 21 and 18 and a pressing force is applied in the axial direction, the axial waviness and twist of the side ring 1 are corrected, especially in the flat part 7.
The flatness of is determined with high precision. Incidentally, since the side ring 1 is supported from the inner diameter side by the punch 19 and the die 18 during pressing, no spot digging occurs. The first aspect of the present invention is achieved through the above steps. Next, in the above-mentioned shaping, if the shape of the pressing part of the punch 19 is made as shown in FIG. Bless with a punch 19 that has an inclination that makes it smaller.

This ringing is caused by the fact that a larger machining amount is applied to the inner circumference b of the side ring 1 than to the outer circumference a, so when the breath-like drift is released, the residual compressive strain is L in the inner circumference b and the outer circumference A tensile stress is generated at a, and the side ring 1 has a spring force that tends to reduce its diameter at each point around the entire circumference. Due to this force, the gap between the cuts 6 in the side ring 1 is not only reduced to zero, but also a pressing force is exerted between the abutting ends. In these shaping operations, as shown in FIG. 11, the gap 25 between the punch 19 and the side ring 1 and the gap 26 between the tie 18 and the side ring 1 are 0.3 to 1
．． Since about 0 TI$l is secured, even if there is a problem with the material thickness of the side ring 1, it can be sufficiently coped with. In addition, in this shaping, in addition to eliminating the gap between the cuts 6, undulations and torsions are naturally corrected. This achieves the second aspect of the present invention. Since the present invention is as described above, the following effects can be obtained according to the present invention.

First, by using a press, the required shape and dimensions of the side ring, such as the flatness and diameter of the flat part, can be easily finished with high precision, and the gap between the cuts can be made zero.

In addition, by using only one process called pressing, shaping to the required shape and dimensions and shaping to zero gaps has greatly reduced the number of man-hours compared to conventional shaping methods, improving work efficiency, It is possible to reduce costs.

In addition, there is no waste of material that occurs during welding and cutting as in the past, so it is possible to save material, and there is no spot digging, so it is possible to prevent the occurrence of defective products. and other great effects.

In the above explanation, a side ring for an automobile wheel was used as an example of a ring having a cut, but the present invention is not limited to this, and the present invention is effective for all metal wheels having a cut at one place on the circumference. Needless to say, it is.

[Brief explanation of the drawing]

Fig. 1 is a partial sectional view of a side ring for an automobile wheel mounted on an automobile wheel rim, Fig. 2 is a front view of the side ring for an automobile wheel, Fig. 3 is a sectional view of Fig. 2, and Fig. 4 is a partial sectional view of an automobile wheel side ring mounted on an automobile wheel rim. Figure 5 is a front view showing each step of the conventional side ring shaping method, Figure 5 is a front view showing each step of another conventional side ring shaping method, and Figure 6 shows the occurrence of spot digging when using the conventional method. 7 is a partial cross-sectional view of the side ring for an automobile wheel; FIG. 8 is a cross-sectional view of the side ring before being pressed when it is attached to a device used for carrying out the present invention; FIG. 9 is a front view of the side ring;
The figure is a cross-sectional view of the device in Figure 8 after being pressed, Figure 10 is a partial cross-sectional view of the punch when applying a large strain to the inner periphery of the side ring, and Figure 11 is the side ring when pressed. FIG. 1... Side ring, 6... Cut,
7... Flat part, 16... Hook part, 19...
...Punch, 21...One...Die, 22...
...Compression part, 23...Sliding part, a...
... Side ring outer circumference side, b... Side ring inner circumference side.

Claims (1)

[Claims] 1. When shaping a ring with cuts, the ring is press-fitted into a tie with a diameter smaller than the outer diameter of the ring before shaping, applying compressive force in the circumferential direction, and also pressed in the axial direction to shape the flat part of the ring. A method for shaping a ring having cuts, which is characterized by correcting undulations and twists. 2. When shaping a ring with cuts, press fit into a tie with a diameter smaller than the outside diameter of the ring before shaping, apply compressive force in the circumferential direction, and press in the axial direction to correct undulations and twists in the flat part of the ring. Also, a method for shaping a ring having cuts, characterized in that a larger pressure strain is applied to the inner circumference of the ring than to the outer circumference.