U.S. patent application number 10/499592 was filed with the patent office on 2005-01-20 for structure for couplingf ball joint and arm.
Invention is credited to Kondoh, Yasuhiro.
Application Number | 20050013657 10/499592 |
Document ID | / |
Family ID | 11738070 |
Filed Date | 2005-01-20 |
United States Patent
Application |
20050013657 |
Kind Code |
A1 |
Kondoh, Yasuhiro |
January 20, 2005 |
Structure for couplingf ball joint and arm
Abstract
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.
Inventors: |
Kondoh, Yasuhiro;
(Toyohashi-Shi, Aichin-Ken, JP) |
Correspondence
Address: |
LADAS & PARRY
26 WEST 61ST STREET
NEW YORK
NY
10023
US
|
Family ID: |
11738070 |
Appl. No.: |
10/499592 |
Filed: |
June 18, 2004 |
PCT Filed: |
December 25, 2001 |
PCT NO: |
PCT/JP01/11396 |
Current U.S.
Class: |
403/122 |
Current CPC
Class: |
F16C 11/0671 20130101;
Y10T 403/32631 20150115; Y10T 403/32737 20150115; F16C 11/0619
20130101; B62D 7/166 20130101; F16C 2326/24 20130101; F16C 11/0638
20130101; B60G 2204/416 20130101 |
Class at
Publication: |
403/122 |
International
Class: |
F16C 011/06 |
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.
Description
TECHNICAL FIELD
[0001] 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
[0002] 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 FIG. 10.
[0003] The ball joint 101 shown in FIG. 10 includes: a ball stud
102 having a spherical ball part 104 and a shank part 103 extending
from the spherical ball part 104; a bearing 105 made of a synthetic
resin, cupping the spherical ball part 104 of the ball stud 102 in
such a manner that the spherical ball part 104 is able to turn and
rock therein, and having an open part 106 in one end; a housing 107
holding the bearing 105 therein and having a small open part 108 in
one end through which the shank part 103 of the ball stud 102
projects and a large open part 109 in the other end; a closing
plate 112 fixed to an end portion of the large open part 109 of the
housing 107 by caulking; and a dust cover 114 having a dust-cover
small open part 115 fitted on the shank part 103 of the ball stud
102 and a dust-cover large open part 116 fitted on the housing 107.
Then, the housing 107 of the ball joint 101 is pressed into a hole
120 of an arm 119, so that the arm 119 and the other parts are
jointed.
[0004] 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.
[0005] In the joint structure of the ball joint 101 and the arm 119
shown in FIG. 10, the outer diameter of the housing 107 of the ball
joint 101 is formed to be a little larger than the inner diameter
of the hole 120 of the arm 119. Thus, when the housing 107 is
pressed into the hole 120 of the arm 119, the housing 107 receives
a pressure from the hole 120 of the arm 119, so that the ball joint
101 is held in the hole 120 of the arm 119.
[0006] However, in the joint structure shown in FIG. 10, the
press-fitting load given from the hole 120 of the arm 119 to the
housing 107 may be also given to the spherical ball part 104 of the
ball stud 102 from the housing 107 through the bearing 105. Thus,
an operational torque necessary for rocking the ball stud 102 may
undesirably become higher than a predetermined value.
DISCLOSURE OF THE INVENTION
[0007] 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.
[0008] 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.
[0009] 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.
[0010] 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.
[0011] 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.
[0012] 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.
[0013] 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.
[0014] 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.
[0015] 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.
[0016] 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.
[0017] 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.
[0018] Preferably, the first groove and the second groove are
arranged to be opposite to each other.
[0019] 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
[0020] FIG. 1 is a partly sectional front elevation of a joint
structure of a ball joint and an arm, according to a first
embodiment of the present invention;
[0021] FIG. 2 is a partly sectional front elevation of a joint
structure of a ball joint and an arm, wherein a retaining ring is
omitted;
[0022] FIG. 3 is a partly sectional front elevation showing a first
stage of work for assembling the ball joint shown in FIG. 1;
[0023] FIG. 4 is a partly sectional front elevation showing a
second stage of work for assembling the ball joint shown in FIG.
1;
[0024] FIG. 5 is a partly sectional front elevation showing a third
stage of work for assembling the ball joint shown in FIG. 1;
[0025] FIG. 6 is a partly sectional front elevation showing a first
stage of work for jointing the ball joint shown in FIG. 1 and an
arm;
[0026] FIG. 7 is a partly sectional front elevation showing a
second stage of work for jointing the ball joint shown in FIG. 1
and the arm;
[0027] FIG. 8 is a partly sectional front elevation of a joint
structure of a ball joint and an arm, according to a second
embodiment of the present invention;
[0028] FIG. 9 is a partly sectional front elevation of a joint
structure of a ball joint and an arm, wherein a gap S is formed;
and
[0029] FIG. 10 is a partly sectional front elevation of a
conventional joint structure of a ball joint and an arm.
BEST MODE FOR CARRYING OUT THE INVENTION
[0030] Preferred embodiments of the present invention will be
described hereinafter with reference to FIGS. 1 to 8.
[0031] FIG. 1 shows a joint structure of a ball joint 1 and an arm
19 according to a first embodiment of the present invention. The
ball joint 1 includes a ball stud 2 having a spherical ball part 4
and a shank part 3 projecting from the spherical ball part 4. A
bearing 5 cups the spherical ball part 4 of the ball stud 2 in such
a manner that the spherical ball part 4 is able to rock and turn
therein. The bearing 5 has an open part 6 in one end thereof to
allow the shank part 3 to rock. The bearing 5 is made of for
example a synthetic resin. The bearing 5 is cupped (housed) in a
substantially cylindrical housing 7.
[0032] 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.
[0033] In addition, in FIG. 1, "14" represents a dust cover. A
small open part 15 of the dist cover 14 internally provided with an
L-shaped ring 17 having a substantially L-shaped cross section is
fitted on an outside periphery of the shank part 3 of the ball stud
2, and a large open part 16 of the dust cover 14 internally
provided with a press-fitting ring 18 is fitted on an outside
periphery of the small open part 8 of the housing 7.
[0034] 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.
[0035] 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 FIG.
2, the retaining ring 13 may be omitted.
[0036] Next, a method of jointing the ball joint 1 and the arm 19
will be described with reference to FIGS. 3 to 7.
[0037] At first, a method of assembling the ball joint 1 will be
described.
[0038] At first, as shown in FIG. 3, the spherical ball part 4 of
the ball stud 2 is inserted into the open part 6 of the bearing 5.
Subsequently, as shown in FIG. 4, under the state wherein the
bearing 5 is fitted on the spherical ball part 4 of the ball stud
2, the shank part 3 of the ball stud 2 is inserted into the large
open part 9 of the housing 7. After the bearing 5 is arranged at a
predetermined position in the housing 7, the closing plate 12 is
inserted into the large open part 9 of the housing 7. Subsequently,
as shown in FIG. 5, an end portion of the large open part 9 of the
housing 7 is inward bent (caulked). Thus, the closing plate 12 is
fixed. In addition, the retaining ring 13 is fitted in the groove
10 of the housing 7 through the side of the shank part 3 of the
ball stud 2. The fitted retaining ring 13 projects a little outward
from the groove 10 of the housing 7 of the ball joint 1, as shown
in FIG. 6.
[0039] A method of press-fitting the ball joint 1 into the hole 20
of the arm 19 will be explained based on FIGS. 6 and 7. At first,
as shown in FIG. 6, a jig 50 is abutted against an end surface on
one side of the hole 20 of the arm 19. The jig 50 has a jig hole 51
consisting of: an one-side open end 52 having the same diameter as
the hole 20 of the arm 19; a the-other-side open end 53 having a
diameter larger than that of the one-side open end 52; and a taper
surface 51a extending from the one-side open end 52 to the
the-other-side open end 53.
[0040] 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 FIG. 7, when the
housing 7 of the ball joint 1 is pressed into the jig hole 51 of
the jig 50, the retaining ring 13 fitted in the groove 10 of the
housing 7 shrinks along the taper surface 51a of the jig 50. Under
the state wherein the retaining ring 13 is caused to shrink to the
same diameter as the inside diameter of the hole 20 of the arm 19
by the taper surface 51a, the retaining ring 13 is pressed into the
hole 20 of the arm 19.
[0041] 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 FIG. 7.
[0042] 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 FIG. 1.
[0043] 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.
[0044] Next, a second embodiment of the present invention will be
explained based on FIG. 8. The ball joint 61 shown in FIG. 8 has
substantially the same structure as the ball joint 1 of the first
embodiment, except for the shape of the housing 67.
[0045] The housing 67 shown in FIG. 8 has circumferential grooves
70, 71 in an outer-circumference surface thereof at respective
positions above and below the equatorial plane X including a center
of the spherical ball part 4 of the ball stud 2. The groove 70 is
formed on the side of the open part 6 of the bearing 5, and a
groove 81 of the hole 20 of the arm 19 is formed at a position
opposite to the groove 70. In the same manner as the first
embodiment, the retaining ring 13 is fitted to extend in the groove
71 of the housing 67 and in the groove 81 of the hole 20 of the arm
19.
[0046] 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.
[0047] 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 FIG. 9.
[0048] 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.
[0049] 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.
* * * * *