JP3719481B2 - Manufacturing method of outer ring part in constant velocity universal shaft joint - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for manufacturing an outer ring portion of a constant velocity universal shaft joint that includes an inner ring portion that supports a rolling element and an outer ring portion that engages with the rolling element.
[0002]
[Prior art]
In a conventional manufacturing method for manufacturing an outer ring portion of a constant velocity universal shaft joint composed of an inner ring portion that supports a rolling element and an outer ring portion that engages with the rolling element by forging and ironing, for example, SHOKO There are methods as disclosed in Japanese Patent Application No. 64-1220 and Japanese Patent Publication No. 2-54171.
[0003]
In the method disclosed in Japanese Examined Patent Publication No. Sho 64-1220, when the cup-shaped inner ring portion forged to form the track groove portion and the inner diameter portion is finished by ironing, the thickness of the track groove portion and the inner diameter portion is increased. In order to prevent unevenness in the axial direction of the edge portion due to the difference, the cup-shaped material is forged by making a difference in thickness between the track groove portion and the inner diameter portion in advance, and the axial extension amount is made substantially constant. .
Further, in the method disclosed in Japanese Patent Publication No. 2-54171, the ironing rate of each portion of the uniform thick portion, the uniform thin portion, and the changed portion from the thick to the thin portion is made uniform. The amount of elongation is made substantially constant.
[0004]
[Problems to be solved by the invention]
In the method disclosed in Japanese Examined Patent Publication No. 64-1220, there is a large difference in the squeezing rate of the track groove bottom, track groove, and inner diameter surface part. In comparison, the accuracy of the track groove portion (track groove surface) requiring accuracy is deteriorated.
[0005]
And in order to secure the strength of the track groove part which becomes the contact point with the roller, it is necessary to make the thickness of the track groove part thicker than the track groove bottom part. Is good. Moreover, since the outer shape of the outer ring becomes smoother when the inner surface portion is thicker, it is easier to ensure the sealing performance when the boot is assembled.
However, in the method disclosed in the above publication, since the thickness of the track groove portion and the inner diameter surface portion is reduced and the thickness of the track groove bottom portion is increased, the strength of the track groove portion and the formability of the outer ring are poor. Also, the seal of boots is poor.
[0006]
In the method disclosed in Japanese Examined Patent Publication No. 2-54171, the ironing rate is uniform over the entire circumference, the accuracy of the track groove is not deteriorated, and the outer shape is cylindrical, so that the moldability and the boot sealing performance are obtained. Is good, but has the following problems:
When a cylindrical material is formed into a cup-shaped intermediate material by backward extrusion, there is a difference in the thickness of the intermediate material, so that the thin portion (track groove bottom) extends in the axial direction due to the difference in processing rate. Therefore, even if this intermediate material is ironed at a uniform ironing rate on the entire circumference, the end surfaces of the original intermediate material are not aligned in the axial direction, and therefore the end surfaces after the ironing are not aligned.
[0007]
Further, in the above two methods in the prior art, a chamfered portion must be cut at the opening edge.
That is, in the above two methods, only the thickness of the track groove portion and the inner diameter portion is differentiated in advance in order to prevent unevenness in the axial direction of the edge portion of the cup-shaped outer ring portion. Since the shaft portion of the inner ring portion contacts and interferes with the opening edge of the outer ring portion in the bending of the constant velocity universal shaft joint, the bending angle is limited, and in order to increase the bending angle, The contact interference area of the opening edge of the part must be scraped off.
[0008]
[Means for Solving the Problems]
In the constant velocity universal shaft joint according to the present invention, the method of manufacturing the outer ring member having the cup-shaped portion in which the track groove portions with which the inner diameter portions and the rolling elements engage are alternately arranged in the circumferential direction is as follows. Is included.
[0009]
(1) The material is pre-formed into a first intermediate material that is a cylindrical body having a desired diameter by upsetting.
(2) The first intermediate material is formed into a second intermediate material composed of a tip small diameter portion, an intermediate taper portion, and a rear end large diameter portion by forward shaft extrusion.
(3) By forming the second intermediate material, the third intermediate material is formed into a third intermediate material including a small-diameter portion serving as a shaft portion and a large-diameter portion having an outer peripheral shape of the outer ring portion.
[0010]
(4) By the combination extrusion of the third intermediate material by front shaft pushing / rear container pushing, the track groove surface and the inner diameter surface with which the rolling elements of the inner ring portion are engaged are alternately arranged on the inner circumferential surface in the circumferential direction, and A fourth intermediate material is formed that substantially matches the desired shape of the outer ring portion whose inner surface is a taper surface that is outwardly expanded at the opening edge.
(5) The fourth intermediate material is formed into the finished dimensions and shape of the outer ring portion by ironing.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
In the embodiment of the present invention, the outer ring portion of a constant velocity universal shaft joint composed of an inner ring portion that supports the rolling element and an outer ring portion that engages with the rolling element, that is, a track groove that engages the inner diameter surface with the rolling element. A method of manufacturing an outer ring portion including a cup body (outer ring portion) and a shaft portion whose surfaces are alternately formed on the inner peripheral surface in the circumferential direction will be described with reference to the drawings.
[0012]
As shown in FIGS. 1 and 2, the constant velocity type universal shaft joint, which is a tripod type shaft joint, includes an outer ring portion A formed by coupling a cup-shaped outer ring portion 1 and a shaft portion 2, and a roller or the like. The inner ring portion 3 is formed by coupling the inner ring portion 3 and the shaft portion 4 that support the moving body on the outer peripheral surface in a rotatable manner.
[0013]
That is, the inner ring portion 3 is inserted into the outer ring portion 1, and the rolling elements supported by the inner ring portion 3 are engaged with the track grooves 11 in the axial direction arranged in parallel to the inner peripheral surface of the outer ring portion 1. Yes.
In the illustrated example, the inner ring portion B includes three ear shafts 32 protruding radially from the outer peripheral surface of the ring body 31 fitted to the tip of the shaft portion 4 at equal circumferential intervals (120 degree intervals). A spherical roller 33, which is a rolling element, is rotatably supported.
[0014]
In the outer ring portion 1 of the outer ring portion A, a track groove portion 11 that forms a track groove surface 11a with which a rolling element engages and an inner diameter surface portion 12 that forms an inner diameter surface 12a are alternately arranged in the circumferential direction on the inner peripheral surface. Yes. In the illustrated example, since the track groove portion 11 and the inner diameter surface portion 12 are formed at three locations, the outer ring portion 1 has a clover-like cross section. (See Figure 2)
[0015]
Moreover, the opening edge of the inner diameter surface portion 12 is thin so that the opening edge of the inner diameter surface portion 12 does not contact and interfere with the shaft portion 4 coupled to the inner ring portion 3 in the bent state in the constant velocity universal shaft joint. It has become.
For example, as in the illustrated example, the inner diameter surface 12 a of the outer ring portion 1 is a tapered surface 13 at the opening edge.
[0016]
The outer ring member 1 is manufactured by the following process using a press.
First step: by upsetting the material cut to a suitable length from round steel, preformed to the first intermediate material W ₁ is a cylinder of the desired diameter of the distal end face chamfered shape. (See Fig. 3 (a))
Second step: The preformed first intermediate material W ₁ is formed into a second intermediate material W ₂ composed of a front end small diameter portion d, an intermediate taper portion e, and a rear end large diameter portion f by forward shaft extrusion. (See Fig. 3 (b))
Third step: The second intermediate material W ₂ is turned up to form a third intermediate material W ₃ composed of a small-diameter portion g serving as a shaft portion and a large-diameter portion h having an outer peripheral shape (clover-shaped cross section) of the outer ring portion. . (See Fig. 3 (c))
[0017]
Fourth step: The fourth intermediate material W ₄ that substantially matches the desired shape of the outer ring portion A is formed by a combination extrusion of the third intermediate material W ₃ by front shaft pressing and rear container extrusion. That is, the small-diameter portion g becomes a shaft portion 4 having a predetermined shape, and the large-diameter portion h becomes an outer ring portion 1 having an inner peripheral surface (track groove surface 11a and inner diameter surface 12a) having a desired shape. (See Fig. 3 (d))
Fifth step: The entire circumference of the fourth intermediate material W ₄ is ironed at a substantially uniform ironing rate to form the outer ring portion A into the finished dimensions and shape. (See Figure 4)
[0018]
The fourth step and the fifth step will be described in more detail. The punches P and P ′ used in the fourth step and the fifth step are fitted to a predetermined hollow portion of the outer ring portion 1 of the outer ring portion. P1 and P1 ′ and subsequent base end portions P2 and P2 ′ that coincide with the contour shape of the outer ring portion 1, and the distal end forming portions P1 and P1 ′ are formed with a protruding strip portion that forms the track groove surface 11a and an inner diameter surface 12a. Are formed on the outer peripheral surface alternately in the circumferential direction, and the outer peripheral surfaces of the base end portions P2 and P2 'continue to the groove portion forming the inner diameter surface 12a via the tapered surface T. .
[0019]
The die D used in the fourth step is formed by a large-diameter hole portion D1 that matches the contour shape of the outer ring portion 1 and a small-diameter hole portion D2 that corresponds to the shaft portion that continues from the bottom thereof.
In the fourth step, the third intermediate material W ₃ is loaded into the die D, and the punch P is pressed toward the third intermediate material W ₃ .
In the fifth step, the fourth intermediate material W ₄ formed in the fourth step is loaded into the punch P ′, and the fourth intermediate material W ₄ is axially directed from the shaft portion 2 toward the opening edge by the die D ′. Squeezing.
[0020]
At that time, the inner diameter surface portion 12 of the outer ring portion 1 is tapered, the thickness is gradually reduced toward the opening end, and the processing rate by the backward extrusion in the fourth step and the ironing rate in the fifth step are gradually increased. As a result, the opening edge of the outer ring portion 1 is made substantially uniform between the inner diameter surface portion 12 and the track groove bottom portion 11b having a large processing rate in the backward extrusion in the fourth step, and unevenness is suppressed.
Further, the taper 13 in the inner diameter surface portion 12 that achieves uniformization of the entire circumference of the opening edge of the outer ring portion 1 in the molding can be obtained even when the shaft portion 4 of the inner ring portion B is bent in the constant velocity universal shaft joint. Avoid contact interference with the opening edge of one.
[0021]
Although the ironing rate changes at the opening of the inner diameter surface portion 12, the ironing rate changes only at the opening, so there is almost no influence on the portion where the accuracy of the track groove surface 11a is required.
In the manufacturing method of the outer ring portion described above, the cup-shaped outer ring portion 1 and the shaft portion 2 of the outer ring portion are integrally formed, but only the outer ring portion 1 may be formed.
Further, the outer shape of the outer ring portion 1 may be a cylindrical shape.
[0022]
【The invention's effect】
In the outer ring portion manufactured by the outer ring portion manufacturing method in the constant velocity universal shaft joint of the present invention, the opening edge portion of the inner ring surface portion of the outer ring portion in which the track groove portion and the inner diameter surface portion are alternately formed in the circumferential direction is It is thin. For example, the opening edge region of the inner diameter surface becomes an outwardly expanding tapered surface, and the thickness of the inner diameter surface portion gradually decreases toward the opening end.
[0023]
Therefore, in the manufacturing, that is, the rear extrusion and the ironing process, the material processing rate (the ironing rate) of the opening portion of the inner diameter surface portion is gradually increased. The opening edge of each is made uniform all around, and irregularities are suppressed.
[0024]
This eliminates the need for a finishing process such as cutting to make the opening edge on the same plane, and increases the productivity.
Further, since the ironing is performed on the entire circumference at a substantially uniform ironing rate, the track groove portion can be machined with high accuracy.
[0025]
And the taper of the opening edge area of the inner diameter surface part in the molding not only achieves uniformization of the entire circumference of the opening edge of the outer ring part, but also when the inner ring part is bent at a constant velocity universal shaft joint. This has the effect of avoiding the shaft portion of the outer ring portion contacting and interfering with the opening edge of the outer ring portion. Therefore, after forming by plastic processing, it is not necessary to perform taper surface processing by cutting or the like again to avoid contact interference.
[0026]
In short, in the method for manufacturing the outer ring portion of the constant velocity universal shaft joint of the present invention, unevenness suppression at the opening edge of the outer ring portion of the outer ring portion and contact interference at the opening edge of the outer ring portion of the shaft portion of the inner ring portion are prevented. Avoidance can be realized at once.
[Brief description of the drawings]
FIG. 1 is a side sectional view of a constant velocity universal shaft joint in which an outer ring portion manufactured by a manufacturing method according to an embodiment of the present invention is used.
FIG. 2 is a front view of the outer ring portion (opening edge side) of the constant velocity universal shaft joint manufactured by the manufacturing method according to the embodiment of the present invention.
FIG. 3 shows upsetting preforming (first step), forward shaft extrusion (second step), upsetting (third step) in the method of manufacturing the outer ring portion of the constant velocity universal shaft joint according to the embodiment of the present invention. And it is explanatory drawing of the combination extrusion (4th process) of front shaft pushing and back container extrusion.
FIG. 4 is an explanatory diagram of ironing (fifth step) in the method of manufacturing the outer ring portion of the constant velocity universal shaft joint according to the embodiment of the present invention.
[Explanation of symbols]
A outer ring portion 1 outer ring portion 11 track groove portion 11a track groove surface 11b track groove bottom portion 12 inner diameter surface portion 12a inner diameter surface 13 taper surface 2 shaft portion B inner ring portion 3 inner ring portion 31 ring body 32 ear shaft 33 spherical roller W ₁ First intermediate material W ₂ Second intermediate material W ₃ Third intermediate material W ₄ Fourth intermediate material P, P 'Punch D Dies d Tip small diameter part e Intermediate taper part f Rear end large diameter part g Small diameter part h Large diameter part

Claims (1)

The manufacturing method including the following process which manufactures the outer ring | wheel part which has the cup-shaped part by which the track groove part which the internal diameter part and rolling element in a constant velocity type universal shaft joint engage with was alternately arranged in the circumferential direction.
(1) A first intermediate material, which is a cylindrical body having a desired diameter, is formed into a second intermediate material having a small distal end portion and a large rear end portion by forward-axis extrusion.
(2) By forming the second intermediate material, the third intermediate material is formed into a third intermediate material including a small-diameter portion serving as a shaft portion and a large-diameter portion having an outer peripheral shape of the outer ring portion.
(3) By the combination extrusion of the third intermediate material by front shaft pushing and rear container pushing, the track groove surface and the inner diameter surface with which the rolling elements of the inner ring portion engage are alternately arranged on the inner circumferential surface in the circumferential direction, and A fourth intermediate material is formed that substantially matches the desired shape of the outer ring portion whose inner diameter surface is a tapered surface that extends outward at the opening edge.
(4) The fourth intermediate material is formed into the finished dimensions and shape of the outer ring portion by ironing.

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