JPH02279265A - Ball groove working method of constant velocity ball joint - Google Patents

Abstract

PURPOSE:To improve the working accuracy of a ball groove by inclining the axial line of a bearing ring along a plane orthogonal with the notch plane so that the axial line is inclined symmetrically with a prestage for the notch plane. CONSTITUTION:The axial line W of a bearing ring is inclined by an angle betaon a notch plane B including the axial line (t) and notch direction (d) of a rotating tool 6 for the axial line (t) of the rotating tool 6. Moreover the axial line W is inclined by an angle alpha for the notch plane B inside the plane A orthogonal with the notch plane B including the axial line B. A 1st ball groove is worked by relatively moving the bearing ring and rotating tool 6 in the cross line direction of a plane A and the notch plane B in this state. The axial line W is then inclined along the plane A so that the axial line W is inclined symmetrically with respect to a prestage for the notch plane B. Thereafter, the bearing ring and rotating tool 6 are relatively moved in the cross line direction to work a 2nd ball groove.

Description

[Detailed Description of the Invention] <Industrial Application Field> This invention has ball grooves that intersect with each other on the inner peripheral surface of the outer ring and the outer peripheral surface of the inner ring to prevent relative displacement in the axial direction between the outer ring and the inner ring. This invention relates to a ball groove machining method for a constant velocity pole joint of an acceptable type.

<Prior Art> The above-mentioned type of constant velocity ball joint is capable of rotating both rotating shafts at a constant velocity even when the pair of rotating shafts connected by the constant velocity ball joint are inclined at a predetermined angle. Because of this, it is widely used in automobiles, etc.

As this constant velocity ball joint, for example,
As shown in Japanese Patent No. 11203, a ball as a torque transmitting element is interposed between an inner ring and an outer ring as raceway rings, and a ball groove having an elliptical cross section in which the ball is engaged is aligned with the axis of the inner and outer rings. while tilted against
Some are formed on the inner circumferential surface of the outer ring and the outer circumferential surface of the inner ring. A plurality of ball grooves are formed at equal angular pitches in the circumferential direction, and adjacent ball grooves in the circumferential direction (hereinafter referred to as first ball grooves and second ball grooves).
are tilted in opposite directions.

The ball grooves of the outer ring and the ball grooves of the inner ring, which are opposite to each other, are arranged so as to intersect each other with the balls sandwiched therebetween.

Conventionally, as a method of machining this ball groove, the twelfth and the first
What is shown in Fig. 3 is provided (Special Publication Act 1986-179).
Publication No.). In this method, the axis W of the outer ring (1) is
As shown in the figure, an angle β is formed on the cutting plane B that includes the axis of the rotating tool and the cutting direction d, with respect to the axis t of the rotating tool.
and as shown in FIG. 13, the bearing ring (1) A first step of machining the first ball groove while performing rotational indexing around the axis W of the bearing ring, and the axis W of the bearing ring is inclined symmetrically with the first step with respect to the cutting plane B. A second step of tilting the axis W along the cutting plane B, and a second step of tilting the axis W along the cutting plane B, and a second step of tilting the axis W along the cutting plane B,
and a third step of machining the ball groove.

This method has the advantage that both the inner ring and the outer ring can be processed using a substantially common processing device.

<Problems to be Solved by the Invention> However, in the second step described above, since the bearing ring (1) is rotated around the point P along the cutting plane B,
The angle β is reversed in the first step and the third step, and in the third step, the rotating tool (6) in the first step is
Machining is performed at a second machining point (CD) located symmetrically to the first machining point (C). Therefore, in the second step, in order to move the machining point from the first machining point (C) to the second machining point (D), in addition to the above-mentioned turning operation of the bearing ring (1), the rotary tool (6) in parallel by a predetermined amount S in the direction along the cutting direction d, which makes the device complicated and large. Furthermore, as described above, since both the bearing ring (1) and the rotary tool (6) are moved, there is also the problem that machining accuracy deteriorates.

Note that if the above point P is set to be the center of gravity of the outer ring (1), the amount of movement S of the rotary tool (61) can be reduced, but it is still necessary to move the rotary tool (6). Therefore, the above problem could not be solved.

This invention has been made in view of the above problems, and provides a ball groove machining method for a constant velocity ball joint that can machine ball grooves with high precision and can downsize and simplify the machining equipment. The purpose is to provide.

Means for Solving the Problems> A method for machining a ball groove for a constant velocity ball joint according to the present invention to achieve the above object has a method for machining a ball groove in a constant velocity ball joint, in which a raceway ring of a constant velocity ball joint has a spherical machined surface. A first ball groove having an elliptical cross section extending in a direction inclined at an angle α with respect to the axis W of the bearing ring by making a cut in a cutting direction d perpendicular to the axis 1j [t of the rotary tool, and the axis W against the first
A constant velocity ball joint in which a first ball groove and a second ball groove having the same cross-sectional shape are alternately formed at equal angular pitches on the circumference, and extend in a direction inclined by the same angle α in the opposite direction to the ball groove. In the ball groove machining method, the axis W of the bearing ring is inclined with respect to the axis t of the rotary tool by an angle β on a cutting plane B including the axis of the rotary tool and the cutting direction d, and In a plane A perpendicular to the cutting plane B including W, the bearing ring and the rotary tool are moved in the direction of the intersection line of the plane A and the cutting plane B, with the bearing ring and the rotary tool being inclined by the angle α with respect to the cutting plane B. 1st by moving relatively
A first step of machining the ball groove of , and inclining the axis W of the bearing ring along the plane A so that the axis W of the bearing ring is symmetrically inclined with respect to the first step with respect to the cutting plane B. This method is characterized by performing a second step and a third step of machining the second ball groove by relatively moving the bearing ring and the rotary tool in the direction of the above-mentioned intersection line.

According to the ball groove machining method for a constant velocity ball joint having the above configuration, in the second step, the axis W of the raceway is inclined with respect to the cutting plane B symmetrically with the first step. Since the axis W is inclined along the plane A, the angle β does not change between the first step and the third step. Therefore, there is no need to move the machining point of the rotary tool.

<Example> Embodiments will be described in detail below with reference to the accompanying drawings showing embodiments.

First, with reference to FIG. 6, a constant velocity ball joint including an outer ring (1) and an inner ring (2) as bearing rings to be processed in the processing method of this embodiment will be described. This constant velocity ball joint includes a ball (3) as a torque transmission element and a cage (4) that holds the ball opening in a single plane between an outer ring (1) and an inner ring (2). is interposed. As shown in FIG. 7, the inner circumferential surface of the outer ring (1) has a first ball groove (1a) and a second ball groove (lb) each having an elliptical cross section and which engage the ball (3). They are alternately formed at equal angular pitches (120 degrees in the figure) in the circumferential direction, and these first ball grooves (la) and second ball grooves (lb) are aligned with respect to the axis of the outer ring (1). They are tilted in opposite directions. Similarly, as shown in FIG. 8, a first ball groove (2a) and a second ball groove (2b) are formed on the outer peripheral surface of the inner ring (2). As shown in FIG. 9, the first ball groove (la) of the outer ring (1) and the second ball groove (2b) of the inner ring (2), which face each other, sandwich the ball (3). They are arranged so that they cross each other. The same applies to the second ball groove (Ib) of the outer ring (1) and the first ball groove (2a) of the inner ring (2).

Next, referring to FIG. 10, the rotary tool (6) to be used
The shape of will be explained. This rotary tool (6) has a cylindrical machined surface (61) and a spherical machined surface (B2) at the tip.
The spherical processing surface (B2) is spherical and has a center at a point (63) (E14) that is offset from the axis t, which is the center of rotation of the rotary tool (6).

This spherical processing i (82) is performed as shown in FIG.
With the axis t of the rotary tool (6) inclined at an angle β with respect to the axis W of the outer ring (1), by engaging the inner peripheral surface of the outer ring (1) and moving the two relative to each other, the cross section is An elliptical ball groove (la) (lb) can be formed.

1 to 5 show diagrams of the principle of machining ball grooves (la) and (lb) in the outer ring (1) using the above-mentioned ellipse creation principle. Here, the rotary tool (6) placed in a horizontal state is movable within the horizontal plane in a direction perpendicular to the axis t (hereinafter referred to as the cutting direction d), and the horizontal plane is the cutting plane B. .

The machining method of this embodiment includes a first step of machining the first ball groove (1a), a second step of changing the set state of the outer ring (1), and a machining of the second ball groove (lb). A third step is performed. First, the first step will be explained. In order to make the ball groove (Ia) elliptical, as shown in FIGS. 1 and 5, the axis W of the outer ring (1) is aligned with the axis of the rotary tool (6) along the cutting plane B, which is a horizontal plane. It is tilted by an angle β with respect to W. Furthermore, in order to incline the ball groove (Ia) with respect to the axis W of the outer ring (1), the axis W of the outer ring (1) is perpendicular to the cutting plane B as shown in FIGS. 2 and 5. Along a plane A consisting of a vertical plane, it is inclined at an angle α with respect to the cutting plane B.

In this state, the intersection line e between the cutting plane B and the plane A is
The first ball groove (la) is ground by relatively moving the outer ring (1) and the rotary tool (6) in the direction.

In addition, in Fig. 1, the machining point (C) of the rotary tool (6)
Processing is performed at.

Next, in the second step, as shown in FIGS. 3 to 5, the axis W of the bearing ring is inclined with respect to the cutting plane B symmetrically with the first step W is inclined along the plane A (in FIG. 5, the axis W is indicated by a chain double-dashed line).

At this time, the axis W is tilted with the center of gravity G of the outer ring (1) as the center of rotation.

Then, in the third step, similarly to the first step,
The second ball groove (1b) is ground by relatively moving the outer ring (1) and the rotary tool (6) in the direction of the intersection line e.

In addition, each step of the first step and the third step is performed on the outer ring (1
) is rotated around the axis W of 12 in this embodiment.
0 degree pitch).

According to this embodiment, in the second step, the outer ring (1)
The axis W is inclined along the plane A so that the axis W is inclined symmetrically with respect to the first step with respect to the cutting plane B, so the angle β is There is no change in the process. Therefore, in the first step and the third step, groove processing can be performed at the same processing point (C) of the rotary tool (6). Therefore, in the second step, there is no need to move the rotary tool (6) and the outer ring (
All you need is the rotation operation in 1). Therefore, the precision of groove machining can be improved, and the machining device can be downsized and simplified.

Note that the method for machining ball grooves in a constant velocity ball joint according to the present invention is not limited to the above-mentioned embodiments. In addition, various design changes can be made without changing the gist of the invention.

<Effects of the Invention> As described above, according to the method for machining a ball groove for a constant velocity ball joint according to the present invention, in the second step, the axis W of the bearing ring is aligned with the first one with respect to the cutting plane B. Since the axis W is inclined along the plane A so as to be inclined symmetrically with the process, the angle β does not change between the first process and the third process, and the angle β does not change between the first process and the third process. In step 3, machining can be performed at the same machining point of the rotary tool. therefore,
Since there is no need to move the rotary tool in the second step, it is possible to improve the machining accuracy of the ball groove and to make the machining device more compact and simple.

[Brief explanation of drawings]

FIG. 1 is a plan view showing the first step of an embodiment of the ball groove machining method for a constant velocity ball joint of the present invention, FIG. Figure 4 is a plan view showing the third process, Figure 4 is a view taken from the direction of arrow (■) in Figure 3, Figure 5 is a perspective view showing the positional relationship between the outer ring and the rotary tool, and Figure 6 is a constant velocity A sectional view of the ball joint, Figures 7 and 8 are diagrams showing the end face shapes of the outer ring and inner ring, Figure 9 is a schematic configuration diagram of the ball groove, Figure 1O is a diagram of the rotating tool, and Figure 11 is a diagram showing the end face shapes of the outer ring and inner ring. FIG. 12 is a cross-sectional view showing the positional relationship between the rotating tool and the outer ring, FIG. 12 is a plan view showing a conventional machining method, and FIG. 13 is a view taken from the direction of arrow R in FIG. 12. (1)...Outer ring as a bearing ring, (2-in...Inner ring as a bearing ring, (la) (2a)...First ball groove, (lb)
(2b)...Second ball groove, (6)...Rotary tool, W...Axis of bearing ring, t...Axis of rotary tool, B
... Cutting plane, A... Plane, e... Intersection line.

Claims (1)

[Claims] 1. Cut into the bearing ring of a constant velocity ball joint with a rotary tool having a spherical machining surface in a cutting direction d perpendicular to the axis t of the bearing ring, and A first ball groove having an elliptical cross section extending in a direction inclined at an angle α, and an angle α opposite to the first ball groove with respect to the axis w.
In the ball groove machining method for a constant velocity ball joint, in which first ball grooves and second ball grooves having the same cross-sectional shape are alternately formed at equal angular pitches on the circumference, A plane A that is perpendicular to the cutting plane B that includes the axis w, with the axis w tilted by an angle β on the cutting plane B that includes the axis t of the rotating tool and the cutting direction d, with respect to the axis t of the rotating tool. The bearing ring and the rotary tool are moved relative to each other in the direction of the intersection line of the plane A and the cutting plane B with the bearing ring and the rotary tool being inclined by the angle α with respect to the cutting plane B to form the first ball groove. a second step of inclining the axis w of the bearing ring along the plane A so that the axis w of the bearing ring is inclined symmetrically to the first step with respect to the cutting plane B; and a third step of machining the second ball groove by relatively moving the bearing ring and the rotary tool in the direction of the above-mentioned intersection line. Method.