JP2513762Y2 - Constant velocity joint - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to an improvement in a constant velocity joint used in a driving force transmission portion of an automobile.

[Prior Art] As a conventional constant velocity joint, a cylindrical shape having one end opened, the inner circumference of the opening end forming the opening has a large diameter, and the inner circumference of the opening end has an opening portion having a ring groove. An outer joint member having a cylindrical inner periphery and a plurality of first guide grooves extending in the cylindrical inner periphery in the axial direction, and an outer joint member coaxially arranged with the outer joint member and having the same number of the first guide grooves on the outer periphery. Inner joint member having a second guide groove extending in the axial direction, and the first and second
It is known that a ball is provided between the guide grooves and transmits a torque, and a cage that holds the ball and is interposed between the inner and outer joint members.

As shown in FIGS. 5 and 6, the outer joint member 1a of the constant velocity joint has a cylindrical inner periphery 11a and a first inner periphery 11a.
The surface of the guide groove 12a is subjected to a quenching treatment by a high frequency or the like to form hardened layers 18a and 19a so as to have high hardness, thereby improving wear resistance. The ring groove 15a formed on the inner circumference of the opening end of the outer joint member holds a snap ring (not shown) for preventing balls (not shown) from coming out of the first guide groove 12a. It is formed by intersecting the cylindrical inner circumference 11a and the first guide groove 12a at a right angle.

[Problems to be Solved by the Invention] In the outer joint member 1a of the constant velocity joint, the opening end inner circumference 13a, which is larger in diameter than the cylindrical inner circumference 11a, is formed by counter boring, etc. Circumference 11a and opening end inner circumference 1
A right-angled step portion 16a is formed between the step portion 16a and 3a. However, when the surface of the cylindrical inner circumference 11a and the surface of the first guide groove 12a are subjected to quenching treatment, stress concentrates on the step portion 16a, and quench cracking easily occurs. Also, the first guide groove 12
When the surface of a is subjected to quenching treatment, quenching cracks are likely to occur at the portion intersecting with the ring groove 15a. Occurrence of these quenching cracks causes a decrease in strength, which is not preferable.

The present invention has been devised in view of the above situation, and a technical object thereof is to provide a constant velocity joint in which occurrence of quench cracking is reduced and strength is improved.

[Means for Solving the Problems] The constant velocity joint according to the first invention is a cylindrical shape having one end opened, and the inner circumference of the opening end forming the opening is large in diameter and has a ring groove on the inner circumference of the opening end. An outer joint member having an opening, an inner periphery having a cylindrical inner periphery and a plurality of first guide grooves extending in the cylindrical inner periphery in the axial direction, and an outer periphery arranged coaxially with the outer joint member. An inner joint member having the same number of axially extending second guide grooves as the first guide grooves, and a ball disposed between the first and second guide grooves for transmitting torque.
A constant velocity joint comprising a cage that holds the ball and is interposed between the inner and outer joint members, wherein the outer joint member is formed between the cylindrical inner periphery and the open end inner periphery. A tapered inner circumference whose inner diameter increases toward the opened opening, and a chamfered portion formed in an R shape at a corner where the tapered inner circumference and the cylindrical inner circumference intersect. A quenching treatment is applied from the peripheral surface portion to the cylindrical inner peripheral surface portion.

A constant velocity joint according to a second aspect is a cylindrical shape having a cylindrical inner circumference with one end opened, and a plurality of first guide grooves extending in the axial direction on the cylindrical inner circumference and having an inner peripheral surface near the open end. An outer joint member having a ring groove that makes one round in the circumferential direction, the outer surface of the guide groove and the inner surface of the cylindrical inner surface being hardened, and an outer joint member that is arranged coaxially with the outer joint member. The second guides that extend in the axial direction by the same number as the first guide grooves on the outer periphery
An inner joint member having a guide groove, balls for transmitting torque arranged between the first and second guide grooves, and a cage holding the ball and interposed between the inner and outer joint members. In the constant velocity joint, the ring groove of the outer joint member has a groove bottom diameter that is larger than the diameter of the inner peripheral surface and is equal to or smaller than the groove bottom diameter of the first guide groove. In addition to being formed, the quenching process for the inner circumference of the cylinder is performed on the surface portion of the inner portion that is separated from the ring groove by a predetermined distance.

[Operation] In the outer joint member according to the first invention, the step between the cylindrical inner circumference and the opening end inner circumference is alleviated by the tapered inner circumference and the chamfered portion formed therebetween, and does not change rapidly.
As a result, local stress concentration is eliminated when the surface portions of these portions are subjected to quenching treatment, and quench cracking is less likely to occur.

In the outer joint member according to the second invention, since the groove bottom diameter of the ring groove is larger than the diameter of the inner peripheral surface and is formed in the range equal to or smaller than the groove bottom diameter of the first guide groove, No step is formed on the bottom of the first guide groove. This makes it difficult for quench cracks to occur when the surface portion of the first guide groove is subjected to quenching treatment.

Further, the quenching process for the cylindrical inner circumference of the outer joint member is performed on the surface portion of the inner portion that is separated from the ring groove by a predetermined distance, and is performed while avoiding the step portion formed by the ring groove, Quench cracks are less likely to occur in the ring groove and in the vicinity of both sides of the ring groove.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

(First Embodiment) FIG. 1 shows a cross-sectional view of a constant velocity joint according to this embodiment, and FIGS. 2 and 3 show cross-sectional views of essential parts showing a quenching-processed portion of an outer joint member.

The constant velocity joint of this embodiment is arranged between the outer joint member 1 having the first guide groove 12, the inner joint member 2 having the second guide groove 23, and the first and second guide grooves 12, 23. The main elements are a ball 3 provided and a cage 4 which holds the ball 3 and is interposed between the inner and outer joint members 1 and 2.

The outer joint member 1 has a cylindrical shape with one end open, and the bottom portion 10 side thereof is fixed to one end of the drive shaft 6.
A cylindrical inner circumference 11 is formed inside the outer joint member 1, and six first guide grooves 12 extending linearly in the axial direction are formed in the cylindrical inner circumference 11 at equal angular intervals. Has been formed. An opening end inner circumference 13 having a diameter larger than that of the cylindrical inner circumference 11 is formed in the opening of the outer joint member 1 so as to have a predetermined axial width. A ring groove 15 in which a snap ring 14 is mounted is formed on the inner circumference 13 of the opening end so as to make one round in the circumferential direction. Then, the cylindrical inner circumference 11 and the opening end inner circumference 13
A tapered inner circumference 16 whose inner diameter gradually increases toward the opening end inner circumference 13 side is formed between and at a downward inclination angle of about 85 °. An R-shaped chamfered portion 17 is formed at the corner where the tapered inner circumference 16 and the cylindrical inner circumference 11 intersect. As shown in FIGS. 2 and 3, the outer joint member 1 thus formed is subjected to induction hardening treatment from the surface of the tapered inner circumference 16 to the surface of the cylindrical inner circumference 11. Has been done. Therefore, the ring groove 15 and the inner circumference 13 of the opening end are not quenched. Further, the quenching treatment of the first guide groove 12 is not performed on the ring groove 15 and the portion on the opening side thereof.

The inner joint member 2 has a short cylindrical shape and is coaxially arranged inside the outer joint member 1. The inner joint member 2 is fixed to one end of the driven shaft 7 by spline coupling. The outer peripheral surface 21 of the inner joint member 2 is formed into a convex spherical surface with a certain curvature, and the outer peripheral surface 21 is formed with six second guide grooves 23 corresponding to the first guide grooves 12. Has been done.

The balls 3 are made of steel and have a right spherical shape, and one ball is provided between the corresponding first and second guide grooves 12 and 23.

The cage 4 is a tubular one having an inner peripheral surface 41 and an outer peripheral surface 43 which are formed with points of equidistant offset on the axial line opposite to each other as centers of curvature. Six ball holding windows 45 are formed in the cage 4 at equal angular intervals along the circumferential direction, and the balls 3 are held by the ball holding windows 45.

The rubber boot 8 that seals the inside of the joint
The outer joint member 1 is mounted on the outer peripheral edge of the outer joint member 1 and the outer peripheral surface of the driven shaft 7 by tightening both ends thereof.

In the constant velocity joint configured as described above, when the drive shaft 6 rotates, its rotational torque is transmitted from the outer joint member 1 to the inner joint member 2 via each ball 3,
The driven shaft 7 rotates at the same speed as the drive shaft 5. Also, the drive shaft 6
When the intersection angle between the driven shaft 7 and the driven shaft 7 changes, the ball 3
Is guided by the first and second guide grooves 12 and 23 to roll, whereby angular displacement of both shafts 5 and 6 is allowed while maintaining constant speed.

As described above, in the constant velocity joint of this embodiment, the tapered inner circumference 16 is formed between the cylindrical inner circumference 11 and the opening end inner circumference 13 of the outer joint member 1, and the tapered inner circumference is formed.
R-shaped chamfer at the corner where 16 and cylindrical inner circumference 11 intersect
17 are formed. Thereby, the tapered inner circumference 16 and the chamfered portion 17 alleviate the step between the cylindrical inner circumference 11 and the opening end inner circumference 13 so as not to change abruptly.
Stress concentration is less likely to occur when quenching is applied, and quench cracking is less likely to occur. In addition, the quenching process uses a tapered inner circumference 16
Since it is applied from the surface part to the surface part of the cylindrical inner circumference 11 and is not applied to the ring groove 15 and the part on the opening side from the ring groove 15 where the crack is likely to occur due to a step, the occurrence of the quench crack is further enhanced It can be reduced. Therefore, the strength of the outer joint member 1 can be improved.

(Second Embodiment) FIG. 4 shows a sectional view of an outer joint member according to this embodiment. In the figure, the same parts as those in the first embodiment are designated by the same reference numerals.

The constant velocity joint of this embodiment is basically the same as that of the first embodiment, but the opening side portion of the outer joint member 1 is different.
A cylindrical inner circumference 11 having a constant diameter up to the opening end is formed on the inner circumference of the outer joint member 1, and a first guide groove 12 similar to the above is formed on the cylindrical inner circumference 11 at an equal angle. It is formed at intervals. A ring groove 15 for holding a snap ring (not shown) is formed in the circumferential direction at a portion near the opening end of the cylindrical inner circumference 11 so as to make one round in the circumferential direction. The ring groove 15 is formed such that its groove bottom diameter dS is larger than the diameter dC of the cylindrical inner circumference 11 and is equal to or smaller than the groove bottom diameter dB of the first guide groove 12. That is, it is formed in a range that satisfies the relationship of dC <dS ≦ dB. Therefore, there is no step at the portion where the cylindrical inner circumference 11 and the ring groove 15 intersect, and the groove bottom of the first guide groove 12 is formed linearly.

Then, with respect to the first guide groove 12, a quenching treatment 18 is applied to the entire surface portion reaching the opening end. On the other hand, with respect to the cylindrical inner circumference 11, a predetermined distance x from the ring groove 15
(X> 0) A quenching treatment 19 is applied to the surface portions of the separated inner portions. Therefore, the ring groove 15 and portions on both sides thereof are not subjected to quenching treatment.

Note that the other structure is the same as that of the first embodiment, and the description thereof is omitted.

As described above, in the constant velocity joint of the present embodiment, the ring groove 15 of the outer joint member 1 has a groove bottom diameter dS larger than the diameter dC of the cylindrical inner circumference 11 and the groove bottom of the first guide groove 12. Since it is formed in the range equal to or smaller than the diameter dB, the step portion due to the ring groove 15 is not formed on the groove bottom of the first guide groove 12. As a result, when the surface of the first guide groove 12 is quenched, local stress concentration is unlikely to occur and quench cracking is unlikely to occur. Further, the quenching treatment for the cylindrical inner circumference 11 is performed on the surface portion of the inner portion which is separated from the ring groove 15 by the predetermined distance x, and is not performed on the ring groove 15 and the portions in the vicinity of both sides thereof. Occurrence is low. Therefore, the strength of the outer joint member 1 can be improved.

[Advantages of the Invention] A constant velocity joint according to the first invention has a tapered inner circumference and a chamfered portion formed between an inner circumference of a cylinder and an inner circumference of an opening end in an outer joint member. Since it is configured so as not to change abruptly, local stress concentration is less likely to occur when the surface of these portions is subjected to quenching treatment, and the occurrence of quench cracks can be reduced.

Further, in the constant velocity joint according to the second invention, the groove bottom diameter of the ring groove provided in the outer joint member is larger than the diameter of the inner peripheral surface and is equal to or larger than the groove bottom diameter of the first guide groove. Since it is formed in a small area and no step is formed on the groove bottom of the first guide groove, it is possible to reduce the occurrence of quench cracks when the surface of the first guide groove is subjected to quenching treatment. Further, since the quenching process for the cylindrical inner circumference of the outer joint member is performed on the surface portion of the inner portion which is separated from the ring groove by a predetermined distance, the occurrence of quench cracks is reduced in the ring groove and the portions on both sides of the ring groove. be able to. Therefore, according to the first and second inventions, the occurrence of quench cracking can be reduced and the strength can be improved.

[Brief description of drawings]

1 to 3 relate to a first embodiment of the present invention. FIG. 1 is a cross-sectional view of a constant velocity joint, and FIGS. 2 and 3 are main-part cross-sections showing a quenching treated portion of an outer joint member. It is a figure. FIG. 4 is a sectional view of an outer joint member according to the second embodiment. Fifth
FIG. 6 and FIG. 6 show a conventional outer joint member, FIG. 5 is a sectional view thereof, and FIG. 6 is a sectional view of an essential part of FIG. 1 ... Outer joint member, 2 ... Inner joint member 3 ... Ball, 4 ... Cage 11 ... Cylindrical inner circumference, 12 ... First guide groove 13 ... Opening end inner circumference, 15 ... Ring groove 16 …… Tapered inner circumference, 17 …… Chamfer 23 …… Second guide groove

Claims (2)

(57) [Scope of utility model registration request] Claim: What is claimed is: 1. A cylinder having an opening at one end, the inner circumference of the opening end forming the opening having a large diameter, and an opening having a ring groove at the inner circumference of the opening end, and having a cylindrical inner circumference and the cylinder. Outer joint member having a plurality of first guide grooves extending in the axial direction on the inner circumference, and second outer members extending coaxially with the outer joint member and extending in the axial direction in the same number as the first guide grooves. An inner joint member having a guide groove, balls for transmitting torque arranged between the first and second guide grooves, and a cage holding the ball and interposed between the inner and outer joint members. In the constant velocity joint, the outer joint member includes a tapered inner circumference whose inner diameter increases toward an opening formed between the cylindrical inner circumference and the opening end inner circumference, and the tapered inner circumference. A chamfer formed in an R shape at the corner where the circumference and the inner circumference of the cylinder intersect. ,
A constant velocity joint characterized in that quenching treatment is applied from a surface portion of the tapered inner circumference to a surface portion of the cylindrical inner circumference. 2. A cylindrical shape having a cylindrical inner circumference whose one end is open, having a plurality of first guide grooves extending in the axial direction on the cylindrical inner circumference, and having one circumference in the circumferential direction on the inner circumferential surface near the opening end. An outer joint member having a ring groove for forming the first guide groove and the surface of the cylindrical inner periphery that has been subjected to a quenching treatment, and the outer joint member coaxially arranged with the outer joint member. 1
An inner joint member having second guide grooves extending in the same number as the guide grooves in the axial direction, balls arranged between the first and second guide grooves for transmitting torque, and the inner and outer members holding the balls for holding the balls. In a constant velocity joint including a cage interposed between both joint members, a ring groove of the outer joint member has a groove bottom diameter larger than a diameter of the inner peripheral surface, and a groove of the first guide groove. It is formed in a range equal to or smaller than the bottom diameter, and the quenching process for the cylindrical inner circumference is performed on the surface portion of the inner portion that is separated from the ring groove by a predetermined distance. Quick joint.