JP2002206563A - Retainer for constant velocity universal joint and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a retainer for a constant velocity universal joint capable of reducing cost and improving production efficiency while accurately and smoothly finishing pocket hole inner faces. SOLUTION: This manufacturing method is for the retainer holding balls arranged between inner and outer rings of the constant velocity universal joint. A cylindrical intermediate product 11a is provided corresponding to a space between the inner and outer rings. A plurality of prepared holes 20a are circumferentially formed at predetermined intervals in a circumferential wall of the cylindrical intermediate product 11a by stamping. Pocket holes 20 are formed by finishing inner faces 22b of the prepared holes 20a into smooth faces by shaving.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a constant velocity universal joint retainer for retaining a torque transmitting ball disposed between an inner ring and an outer ring of a constant velocity universal joint, and a method of manufacturing the same.

[0002]

2. Description of the Related Art In a power transmission device for a vehicle, a constant speed rotational motion is transmitted from an input portion to an output portion, for example, at a connection point between a drive shaft and a wheel or a connection point between a transmission and a propeller shaft. Constant velocity universal joints are used in various places.

The constant velocity universal joint shown in FIG.
An inner ring (3) and an outer ring (4) connected to (2), a plurality of torque transmitting balls (5) arranged between the two wheels (3) and (4), and a ball for holding the balls (5); Cage (6)
And

The inner ring (3) has an outer surface formed in an outer spherical shape, and a ball engaging groove (3a) extending along the axial direction on the outer surface.
Are formed at predetermined intervals in the circumferential direction. The outer ring (4) has an inner surface formed into an inner spherical shape,
On its inner surface, a plurality of ball engaging grooves (4a) along the axial direction are formed at predetermined intervals in the circumferential direction corresponding to the ball engaging grooves (3a) of the inner ring (3).

[0005] As shown in Fig. 6, the retainer (6) has a substantially cylindrical main body (7) so as to extend between the two wheels (3) and (4). A plurality of ball holding pocket holes (8) are formed in the peripheral side wall of the main body (7) at predetermined intervals along the circumferential direction.

The retainer (6) is disposed between the two wheels (3) and (4), and the ball (5) is inserted between the two engagement grooves (3a) and (4a) between the two wheels (3) and (4). In a state of being housed so as to be engaged in the circumferential direction, it is housed and held in the pocket hole (8) of the cage (6).

In this constant velocity universal joint, for example, the rotation of one of the rotating shafts (1) causes the inner ring (3) to rotate, and at the same time, the ball (5) rotates around the axis together with the retainer (6). The outer ring (4) rotates following the rotation of the outer ring (2), and the other rotation shaft (2) rotates at the same speed as the one rotation shaft (1).

[0008] Such a constant velocity universal joint includes a ball (5).
Is engaged with the engagement grooves (3a) and (4a) of the two wheels (3) and (4) to transmit rotational torque between the two wheels (3) and (4). Positional accuracy is required, and accordingly, high dimensional accuracy is required for the retainer (6), particularly the ball holding pocket hole (8).

Under these circumstances, when manufacturing the conventional cage for constant velocity universal joints (6), first, a metal material such as chrome steel is machined to form a cylindrical intermediate product whose inner and outer surfaces are spherical. Get.

Subsequently, a plurality of pilot holes as pocket holes (8) are formed in the peripheral side wall of the cylindrical intermediate product at predetermined intervals along the circumferential direction by punching.

Next, the inner surface of the pilot hole is subjected to finishing by cutting such as broaching to remove a broken portion, to improve surface roughness and dimensional accuracy, and to obtain a highly accurate and smooth inner surface. The cage (6) is obtained by finishing the pocket hole (8) (JP-A-53-54642).

[0012]

However, in the conventional method for manufacturing the cage (6), when finishing the inner surface of the pocket hole (8), cutting such as broaching is performed. This broaching is performed by pressing a tool having a large number of cutting edges, each of which is a combination of a roughing blade and a finishing blade, arranged in the dimension order, against the inner surface of the pilot hole as the pocket hole (8), and pulling out the tool. This method finishes the inner surface of the hole, requires an expensive dedicated device, and causes an increase in cost. Furthermore, cutting such as broaching is different from pressing such as pilot hole punching,
The productivity is low, and this broaching has a problem that the overall production efficiency is reduced and the cost is further increased.

The present invention solves the above-mentioned problems of the prior art, and can reduce the cost and improve the production efficiency while forming the inner surface of the pocket hole with high dimensional accuracy and a good smooth surface. An object of the present invention is to provide a universal joint retainer and a method for manufacturing the same.

[0014]

In order to achieve the above object, the first aspect of the present invention is arranged between an inner ring and an outer ring of a constant velocity universal joint and holds a ball for transmitting torque between these two wheels. A method for manufacturing a constant velocity universal joint retainer in which a plurality of pocket holes to be formed are formed at predetermined intervals in a circumferential direction, comprising: a step of obtaining a cylindrical intermediate product corresponding to the space between the inner ring and the outer ring; Forming a plurality of pilot holes at predetermined intervals in the circumferential direction on the peripheral side wall of the cylindrical intermediate product, and shaving the inner surface of the pilot hole into a smooth surface to form the pocket hole. And a step that includes

In the method of manufacturing a cage for a constant velocity universal joint according to the first aspect of the present invention, the pilot hole formed by punching
Since it is finished by shaving, the inner surface of the pocket hole can be finished with high dimensional accuracy and a good smooth surface, and it does not require expensive dedicated broaching equipment, as well as pilot hole punching and shaving. The pocket hole can be formed only by pressing such as processing.

In the first aspect of the present invention, it is preferable to adopt a configuration in which, of the inner surface of the pilot hole, only the middle of the inner surface orthogonal to the axial direction is subjected to the shaving process.

That is, when this configuration is adopted, the shaving amount by shaving can be minimized, the working force at the time of shaving can be reduced, and, for example, a small press machine having a small press pressure can be used. Can also be reliably processed.

On the other hand, the second invention specifies a constant velocity universal joint retainer obtained by the manufacturing method of the first invention.

[0019]

FIG. 1 is a sectional view showing a retainer (10) for a constant velocity universal joint according to an embodiment of the present invention. As shown in the figure, the retainer (10) includes a substantially cylindrical main body (11), and a peripheral side wall of the main body (11) for holding a torque transmitting ball (5). Six pocket holes (20) are formed at equal intervals in the circumferential direction.

The outer surface of the peripheral side wall of the cylindrical body (11) can be guided by the inner surface of the outer ring of the constant velocity universal joint (see FIG. 5).
In addition to being formed in an outer spherical shape, the inner peripheral surface of the peripheral side wall is formed in an inner spherical shape so that it can be guided by the inner ring outer surface of the constant velocity universal joint.

As shown in FIGS. 1 and 2, the pocket hole (20) is symmetrical with respect to the axis (O), has a substantially rectangular shape having a short axial direction and a long circumferential direction, and has a short side portion. (2
1) is formed in a substantially arc shape having a large radius of curvature, is disposed substantially parallel to the axis (O), and has a long side (2).
2) are arranged orthogonal to the axis (O) and parallel to the circumferential direction. Furthermore, the corner (23) of the pocket hole (20)
Are formed in an arc shape occupying about 20% of the short side (21).

As shown by the imaginary line in FIG. 1, the pocket (20) is provided with the ball (5) corresponding to the middle (22a) of the long side portion (22). The width (W) in the direction parallel to O) requires high dimensional accuracy in order to minimize play during operation, and especially the middle (22a) of the long side (22) is Since this part guides 5), higher dimensional accuracy is required.

In the present embodiment, the retainer (10) is manufactured as follows.

First, a pipe made of chromium steel is cut into a predetermined length, and then the outer shape is formed into a substantially spherical shape by drawing. Then, as shown in FIG.
The outer surface is formed into an outer spherical shape corresponding to the inner surface of the outer ring of the constant velocity universal joint, and the inner surface is formed into an inner spherical shape corresponding to the outer surface of the inner ring of the constant velocity universal joint, thereby forming a substantially cylindrical intermediate portion. The product (11a) is obtained.

Next, as shown in FIG.
A pocket hole forming region in the peripheral side wall of a) is punched out by press working to form a pilot hole (20a).

More specifically, the inner peripheral edge of one end face of the cylindrical intermediate product (11a) is chucked, and a punch for punching a prepared hole is formed along the axis (O) from the inside to the outside of the product. A first hole (20a) is formed by punching in a direction perpendicular to the direction. Next, the intermediate product (11a)
It is rotated by a predetermined amount around the axis by the indexing and splitting mechanism, and punched in the same manner as above to form a second pilot hole (20a). 20a) is formed.

As described above, a high dimensional accuracy is required in the middle (22a) of the long side portion of the pilot hole (pocket hole 20) for guiding the ball. Therefore, in this pilot hole punching step, the clearance of the punch and die (die) to be used is set to a value unique to the present invention. That is, in the present embodiment, the dimension of the punch corresponding to the width direction (W) in the middle (22a) of the long side of the prepared hole (20a) is 14.67 mm, and the dimension of the die is 15.03.
mm, the clearance is 0.3
6 mm and 0.18 mm on one side. The thickness of the intermediate product (11a) is adjusted to 4.0 mm, and the clearance on one side is 4.5% based on this thickness.
It is set extremely small in consideration of the fact that the clearance on one side in normal punching is about 10% of the product thickness.

In the present invention, the clearance on one side with respect to the product wall thickness of the die for punching a prepared hole is
The lower limit is preferably set to 2.0% to 8.0%, and more preferably, the lower limit is set to 3.5% or more and the upper limit is set to 5.5% or less. That is, if the clearance deviates from the above specified range, it is difficult to form the allowance (25) for the shaving process in the subsequent step to an appropriate size, so that the shaving by the shaving process is difficult. There is a possibility that it cannot be performed stably.

Further, in the preparation of the punched hole, the mold clearance at a portion other than the middle portion (22a) of the long side portion is one side of the product thickness on one side, similarly to the normal punching process.
0%, that is, in this embodiment, 0.4% on one side.
It is set to 0 mm.

After forming the pilot hole (20a) in this way, as shown in FIGS. 1 and 2, the inner surface (2a) at the middle (22a) of the longitudinal side of the pilot hole (20a) is formed by shaving.
The broken portion of 2b) is removed, and the inner surface (22b) is made a smooth surface orthogonal to the axis to form a pocket hole (20).

More specifically, it is the same as the above-described pilot hole punching process. One end face of the intermediate product (11a) is chucked, and the shaving punch is moved from the inside to the outside of the product along the axis (O). The step of punching in a direction perpendicular to the direction of the cutting and the step of rotating a predetermined amount around the axis by an indexing and splitting mechanism are alternately performed to perform shaving processing on all the pilot holes (20a).

Here, shaving processing is a kind of precision shearing processing in which the peripheral surface in the thickness direction of a material which has been subjected to normal shearing processing in press processing is slightly cut off and finished, and a commonly used press device is used. Thus, it can be applied to a wide range of materials, and a good surface can be obtained.

In this embodiment, in this shaving process, the size of the punch corresponding to the width direction (W) at the middle (22a) of the long side portion of the pocket hole (20) is 15.1.
3 mm, die size 15.23 mm, clearance 0.10 mm on both sides, 0.1 mm on one side.
It is set to 05 mm. That is, the product thickness is 4.0m
m, the clearance on one side is set to 2.5%.

In the present invention, the clearance on one side with respect to the product thickness in the shaving mold is preferably set to 1.0 to 4.0%, more preferably, the lower limit is 1.5%. As described above, the upper limit is preferably set to 3.5% or less. That is, if the clearance deviates from the above specified range, there is a possibility that the shaving process cannot be performed stably.

In this embodiment, the shaving width in the shaving process is, in other words, "the intermediate width direction dimension of the shaving punch (15.13 mm)"-"the intermediate width direction dimension of the pilot hole punching process (15.13 mm). 14.67m
m) ”is 0.46 mm, and the product thickness (4 m
m) is set to 11.5%.

Here, in the present embodiment, the scraping width with respect to the product thickness is preferably set to 7 to 14%, more preferably, the lower limit is set to 9.0% or more and the upper limit is set to 12.0% or less. That is, if the shaving width is too small, the entire required area of the prepared hole (20a) cannot be evenly shaved, which may make it difficult to secure sufficient dimensional accuracy. Conversely, if the shaving width is too large, a fracture surface due to shearing is formed as in the case of ordinary punching, and it may be difficult to obtain a good finished surface.

After finishing the pocket holes (20) by shaving, a cage (10) is formed by performing heat treatment such as carburizing and quenching and further post-treatment such as polishing.

As described above, the cage (1) of the present embodiment
According to the manufacturing method of 0), when forming the pocket hole (20), the pilot hole (20a) formed by punching is
Since it is finished by shaving, the required inner surface (22b) of the pocket hole (20) can be finished with high dimensional accuracy and a good smooth surface, and an expensive dedicated device for broaching is not required. Therefore, cost can be reduced.

In the present embodiment, the inner surface (22b) of the middle (22a) of the long side portion (22a) of the pocket hole (20) is formed by the above-described pilot hole punching process and shaving process.
Was able to be finished to a good smooth surface with a surface roughness of Rmax 2.0 or less.

In this embodiment, since the pocket hole (20) is formed only by press working such as punching for forming a preliminary hole and shaving for finishing, low efficiency broaching is required. And not on
Since there is no intervening cutting work different from press working such as broaching, the manufacturing process can be shifted smoothly, production efficiency can be improved, and costs can be further reduced.

In the present invention, the pilot hole (20a)
, Only the inner surface (22b) of the middle of the long side (22a),
That is, since only the required area is finished by shaving, the shaving amount by shaving can be minimized, the press pressure of the press device can be reduced, and the size of the device can be reduced. There is an advantage.

On the other hand, in the present embodiment, the die for punching the pilot hole and the die for shaving are slidable in the left-right direction and the like, and the chucked intermediate product (1) is formed.
In contrast to 1a), a die set having a structure in which a desired die of the prepared hole punching die and the shaving die can be moved close to the intermediate product (11a) to be freely set in the desired die. When the intermediate product (11a) that has been chucked once is formed, the two dies can be moved by moving the two dies so that the punching process and the shaving process can be performed. The production efficiency can be further improved.
In particular, in this case, it is not necessary to re-grip the intermediate product (11a) by chucking when shifting from the pilot hole punching processing to the shaving processing. Can be reliably prevented, accurate shaving can be performed at an accurate position, and the inner surface of the pocket hole (20) can be finished with higher precision and smoothness. In addition, since both the punching process and the shaving process can be performed by a single press, the cost and the size of the apparatus can be further reduced.

[0043]

As described above, according to the method for manufacturing the constant velocity universal joint retainer of the first invention, when forming the pocket hole, the pilot hole formed by punching is finished by shaving. Because it is a thing, the inner surface of the pocket hole can be finished with high accuracy and smoothness,
Since an expensive dedicated device for broaching is not required, the cost can be reduced. In addition, since pocket holes are formed only by press working such as pilot hole punching processing and shaving processing, cutting processing such as low-efficiency broaching is not used, and is different from press processing such as cutting processing. Since the cutting process is not involved, there is an effect that the manufacturing process can be smoothly shifted, the production efficiency can be improved, and the cost can be further reduced.

In the first aspect of the present invention, when shaving is performed only on a required area of the inner surface of the prepared hole, the shaving amount by shaving can be suppressed to a necessary minimum, and the processing force during shaving, that is, There is an advantage that the press pressure and the like can be reduced, and the size of the apparatus can be reduced.

Since the second invention specifies the constant velocity universal joint retainer obtained by the manufacturing method of the first invention, the same effects as above can be obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a retainer for a constant velocity universal joint according to an embodiment of the present invention.

FIG. 2 is a front view showing a pocket hole in the cage according to the embodiment.

FIG. 3 is a cross-sectional view showing an intermediate product for obtaining the retainer of the embodiment.

FIG. 4 is a sectional view showing the intermediate product of the embodiment in a state after forming a pilot hole.

FIG. 5 is a sectional view showing a constant velocity universal joint.

FIG. 6 is a perspective view showing a conventional cage for a constant velocity universal joint.

[Explanation of symbols]

 5: Torque transmitting ball 10: Cage 11: Main body 11a: Intermediate product 20: Pocket hole 20a: Prepared hole 22a: Middle of long side 22b: Inner surface of middle of long side O: Axis

Claims (3)

[Claims] 1. A plurality of pocket holes, which are arranged between an inner ring and an outer ring of a constant velocity universal joint and hold a ball for transmitting torque between these two rings, are formed at predetermined intervals in a circumferential direction. A method of manufacturing a retainer for a speed universal joint, comprising the steps of: obtaining a cylindrical intermediate product corresponding to a space between the inner ring and the outer ring; and performing a punching process on a peripheral side wall of the cylindrical intermediate product at predetermined intervals in a circumferential direction. Forming a plurality of pilot holes, and finishing the inner surface of the pilot hole to a smooth surface by shaving to form the pocket holes. 2. The method of manufacturing a constant velocity universal joint retainer according to claim 1, wherein the shaving process is performed only on an intermediate portion of the inner surface of the pilot hole that is perpendicular to the axial direction. 3. A retainer for a constant velocity universal joint obtained by the production method according to claim 1.