Structure for couplingf ball joint and arm
The invention is a joint structure of a ball joint and an arm, which includes: a ball stud having a spherical ball part and a shank part extending from the spherical ball part; a bearing cupping the spherical ball part of the ball stud; a housing holding the bearing therein; and an arm having a hole into which the housing is inserted. The housing has a circumferential groove in an outer-circumference surface thereof. The housing is adapted to be pressed into the hole of the arm. The groove functions to weaken a load by the arm after the housing is pressed into the hole of the arm. Thus, a pressure to the spherical ball part of the ball stud is inhibited so that a sliding characteristic of the ball stud is improved.
The present invention relates to a joint structure of a ball joint and an arm, which is used in a suspension system and a steering system and the like of for example an automobile.
BACKGROUND ART Conventionally, as a joint in a suspension system and a steering system of an automobile, a ball joint and an arm are often jointed. A conventional example of joint structure of a ball joint and an arm is shown in
The ball joint 101 shown in
The outer diameter of the housing 107 of the above ball joint 101 is formed to be a little larger than the inner diameter of the hole 120 of the arm 119. Then, when the housing 107 of the ball joint 101 is pressed into the hole 120 of the arm 119, the ball joint 101 and the arm 119 are jointed.
In the joint structure of the ball joint 101 and the arm 119 shown in
However, in the joint structure shown in
Accordingly, it is an object of the present invention to solve the aforesaid problems and to provide a joint structure of a ball joint and an arm wherein an operational torque necessary for rocking a ball stud is reduced.
This invention is a joint structure comprising: a ball stud having a spherical ball part and a shank part extending from the spherical ball part; a bearing cupping the spherical ball part of the ball stud; a housing holding the bearing therein; and an arm having a hole into which the housing is inserted; wherein the housing has a circumferential groove in an outer-circumference surface thereof; the housing is adapted to be pressed into the hole of the arm; and the groove functions to weaken a load by the arm after the housing is pressed into the hole of the arm.
According to the invention, since the groove of the housing effectively weakens the press-fitting load from the hole of the arm, a pressure to the spherical ball part of the ball stud is inhibited so that a sliding characteristic of the ball stud is improved.
Preferably, the groove is formed at a position corresponding to an equatorial plane including a center of the spherical ball part. In the case, the press-fitting load from the hole of the arm is weakened very effectively.
Alternatively, the housing may have two circumferential grooves in the outer-circumference surface thereof. In the case, preferably, the two grooves may be formed in such a manner that an equatorial plane including a center of the spherical ball part is sandwiched between the two grooves. In the case too, the press-fitting load from the hole of the arm is weakened very effectively.
In addition, the invention is a joint structure comprising: a ball stud having a spherical ball part and a shank part extending from the spherical ball part; a bearing cupping the spherical ball part of the ball stud; a housing holding the bearing therein; and an arm having a hole into which the housing is inserted; wherein the hole has a circumferential groove in an inner-circumference surface thereof; the housing is adapted to be pressed into the hole of the arm; and the groove functions to weaken a load by the arm after the housing is pressed into the hole of the arm.
According to the invention, since the groove of the hole effectively weakens the press-fitting load, a pressure to the spherical ball part of the ball stud is inhibited so that a sliding characteristic of the ball stud is improved.
Preferably, the groove is formed at a position corresponding to an equatorial plane including a center of the spherical ball part. In the case, the press-fitting load from the hole of the arm is weakened very effectively.
Alternatively, the hole may have two circumferential grooves in the inner-circumference surface thereof. In the case, preferably, the two grooves may be formed in such a manner that an equatorial plane including a center of the spherical ball part is sandwiched between the two grooves. In the case too, the press-fitting load from the hole of the arm is weakened very effectively.
In addition, the invention is a joint structure comprising: a ball stud having a spherical ball part and a shank part extending from the spherical ball part; a bearing cupping the spherical ball part of the ball stud; a housing holding the bearing therein; and an arm having a hole into which the housing is inserted; wherein the housing has a first circumferential groove in an outer-circumference surface thereof; the hole has a second circumferential groove in an inner-circumference surface thereof; the housing is adapted to be pressed into the hole of the arm; and the first groove and the second groove function to weaken a load by the arm after the housing is pressed into the hole of the arm.
According to the invention, since the groove of the housing and the groove of the hole weaken the press-fitting load to the housing by the hole of the arm very effectively, a pressure to the spherical ball part of the ball stud is inhibited so that a sliding characteristic of the ball stud is improved.
Preferably, the first groove and the second groove are arranged to be opposite to each other.
In addition, when the outer-circumference surface of the housing is cylindrical and the inner-circumference surface of the hole is cylindrical, it is preferable that a retaining ring is arranged in the first groove and the second groove, the retaining ring having an inner diameter smaller than an outer diameter of the housing and an outer diameter larger than an inner diameter of the hole.
BRIEF DESCRIPTION OF THE DRAWINGS
Preferred embodiments of the present invention will be described hereinafter with reference to FIGS. 1 to 8.
The housing 7 has a small open part 8 on one side, through which the shank part 3 of the ball stud 2 projects, and a large open part 9 on the other side, which is to be caulked to fix a disk-like closing plate 12 in an inner circumference thereof. In addition, a circumferential groove 10 is formed in an outer-circumference surface of the housing 7 crossing an equatorial plane X including a center of the spherical ball part 4 of the ball stud 2. In addition, a flange 11 is circumferentially formed at an outside periphery of the large open part 9 of the housing 7.
In addition, in
On the other hand, the arm 19 has a hole 20 into which the housing 7 is fitted. In the hole 20, a circumferential groove 21 is formed in an inner-circumference surface thereof crossing the equatorial plane X including a center of the spherical ball part 4 of the ball stud 2. Thus, the housing 7 of the ball joint 1 is press-fitted into the hole 20 in such a manner that the groove 21 of the hole 20 and the groove 10 of the housing 7 are opposite to each other.
In the embodiment, a C-shaped retaining ring 13 in which one portion has been cut out is pressed into the groove 21 of the hole 20 and the groove 10 of the housing 7. Of course, as shown in
Next, a method of jointing the ball joint 1 and the arm 19 will be described with reference to FIGS. 3 to 7.
At first, a method of assembling the ball joint 1 will be described.
At first, as shown in
A method of press-fitting the ball joint 1 into the hole 20 of the arm 19 will be explained based on
The one-side open end 52 is aligned with an open end on one side of the hole 20 of the arm 19. Then, the shank part 3 of the ball stud 2 and housing 7 are pressed into the-other-side open end 53 of the jig hole 51 of the jig 50. As shown in
Before the flange 11 of the housing 7 is abutted against the-other-side open end 53 of the jig hole 51, the jig 50 is divided into two parts, and the two parts move away from the arm 19 in respective directions shown by arrows in
Next, when the groove 10 of the housing 7 reaches a position opposite to the groove 21 of the hole 20 of the arm 19, the retaining ring 13 that has been caused to shrink expands to an original state thereof. Thus, the retaining ring 13 extends both in the groove 10 of the housing 7 and in the groove 21 of the hole 20 of the arm 19, so that the ball joint 1 and the arm 19 are firmly jointed, as shown in
In the joint structure of the ball joint 1 and the arm 19 of the embodiment, the groove 10 formed in the housing 7 of the ball joint 1 is located at the same level as the equatorial plane X including a center of the spherical ball part 4 of the ball stud 2. Thus, the groove 10 weakens the press-fitting load from the hole 20 of the arm 19 very effectively. Thus, a pressure given to the spherical ball part 4 of the ball stud 2 is inhibited so that a sliding characteristic of the ball stud 2 is improved. Specifically, an operational torque necessary for rocking the ball stud 2 can be reduced.
Next, a second embodiment of the present invention will be explained based on
The housing 67 shown in
In the joint structure of the ball joint 61 and the arm 19 of the embodiment, the grooves 71, 72 formed in the outer-circumference surface of the housing 67 weaken the press-fitting load from the hole 20 of the arm 19. Thus, a pressure given to the spherical ball part 4 of the ball stud 2 is inhibited so that a sliding characteristic of the ball stud 2 is improved. Specifically, an operational torque necessary for rocking the ball stud 2 can be reduced.
In addition, it was found that it is preferable that the outer diameter of the housing 67 between the grooves 70 and 71 is formed to be a little smaller than the inner diameter of the hole 20 of the arm 19 to form a gap S, as shown in
In the case, the grooves 71, 72 formed in the outer-circumference surface of the housing 67 and the gap S weaken the press-fitting load from the hole 20 of the arm 19. Thus, a pressure given to the spherical ball part 4 of the ball stud 2 is inhibited so that a sliding characteristic of the ball stud 2 is improved. Specifically, an operational torque necessary for rocking the ball stud 2 can be reduced.
Herein, in the joint structures of the ball joint and the arm of the respective embodiments, the retaining ring 13 is arranged between the groove of the housing and the groove 21 of the hole 20 of the arm 19. This is effective in retaining the joint of the housing and the arm 19. According to this arrangement of the retaining ring 13, it is unnecessary to extend a length of the housing in an axial direction, which can prevent size-expansion of the ball joint.
Claims
1. A joint structure comprising:
- a ball stud having a spherical ball part and a shank part extending from the spherical ball part;
- a bearing cupping the spherical ball part of the ball stud;
- a housing holding the bearing therein; and
- an arm having a hole into which the housing is inserted;
- wherein
- the housing has a circumferential groove in an outer-circumference surface thereof;
- the housing is adapted to be pressed into the hole of the arm; and
- the groove functions to weaken a load by the arm after the housing is pressed into the hole of the arm.
2. A joint structure according to claim 1, wherein
- the groove is formed at a position corresponding to an equatorial plane including a center of the spherical ball part.
3. A joint structure according to claim 1, wherein
- the housing has two circumferential grooves in the outer-circumference surface thereof.
4. A joint structure according to claim 3, wherein
- the two grooves are formed in such a manner that an equatorial plane including a center of the spherical ball part is sandwiched between the two grooves.
5. A joint structure comprising:
- a ball stud having a spherical ball part and a shank part extending from the spherical ball part;
- a bearing cupping the spherical ball part of the ball stud;
- a housing holding the bearing therein; and
- an arm having a hole into which the housing is inserted;
- wherein
- the hole has a circumferential groove in an inner-circumference surface thereof;
- the housing is adapted to be pressed into the hole of the arm; and
- the groove functions to weaken a load by the arm after the housing is pressed into the hole of the arm.
6. A joint structure according to claim 5, wherein
- the groove is formed at a position corresponding to an equatorial plane including a center of the spherical ball part.
7. A joint structure according to claim 5, wherein
- the hole has two circumferential grooves in the inner-circumference surface thereof.
8. A joint structure according to claim 7, wherein
- the two grooves are formed in such a manner that an equatorial plane including a center of the spherical ball part is sandwiched between the two grooves.
9. A joint structure comprising:
- a ball stud having a spherical ball part and a shank part extending from the spherical ball part;
- a bearing cupping the spherical ball part of the ball stud;
- a housing holding the bearing therein; and
- an arm having a hole into which the housing is inserted;
- wherein
- the housing has a first circumferential groove in an outer-circumference surface thereof;
- the hole has a second circumferential groove in an inner-circumference surface thereof;
- the housing is adapted to be pressed into the hole of the arm; and
- the first groove and the second groove function to weaken a load by the arm after the housing is pressed into the hole of the arm.
10. A joint structure according to claim 9, wherein
- the first groove and the second groove are arranged to be opposite to each other.
11. A joint structure according to claim 10, wherein
- the outer-circumference surface of the housing is cylindrical,
- the inner-circumference surface of the hole is cylindrical, and
- a retaining ring is arranged in the first groove and the second groove, the retaining ring having an inner diameter smaller than an outer diameter of the housing and an outer diameter larger than an inner diameter of the hole.
Type: Application
Filed: Dec 25, 2001
Publication Date: Jan 20, 2005
Inventor: Yasuhiro Kondoh (Toyohashi-Shi, Aichin-Ken)
Application Number: 10/499,592