JP2005282853A - Ball joint - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve durability of a ball joint against abrasion, while reducing friction resistance of the ball joint. <P>SOLUTION: In sliding surfaces 21c and 22c of a bearing 14 to be brought in slide-contact with a spherical head of a ball stud of the ball joint, the sliding surface 22c positioned in a load transmitting direction between the ball stud is formed from a material having high strength like nylon and excellent abrasion resistance, and the sliding surface 21c positioned in a direction crossing the load transmitting direction is formed from a material having low strength such as poly-urethane and a low coefficient of friction. With this structure, the ball joint can be smoothly operated by reducing friction resistance, while improving durability against abrasion of the bearing 14. In a ball joint for connecting a suspension arm and a knuckle to each other, the longitudinal direction of the suspension arm is the load transmitting direction. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention has a ball stud having a spherical head and a handle extending from the head, a bearing for swingably supporting the head of the ball stud, and an opening from which the handle of the ball stud protrudes. And a ball joint including a housing for supporting the bearing.

A ball joint in which a synthetic resin bearing is supported inside a housing and a spherical head of a ball stud is slidably fitted to the bearing is known from Patent Document 1 below.
JP-A-8-128438

  By the way, in order to operate the ball joint smoothly, it is necessary to reduce the frictional resistance between the bearing and the head of the ball stud. However, if the bearing is made of a low-strength material in order to reduce the frictional resistance, the bearing There is a problem that the durability of the ball joint is lowered due to early wear or sag. Further, if the bearing is made of a material having high strength in order to enhance durability against drooping and wear, there is a problem that the frictional resistance increases and the ball joint does not operate smoothly. High-strength materials generally have high hardness and high elasticity, so if the bearing is made of a high-strength material, the pressure applied when the ball stud of the ball joint is stored in the housing increases, and the friction resistance of the ball joint increases. .

  The present invention has been made in view of the above circumstances, and an object thereof is to improve durability against drooping and wear while reducing the frictional resistance of the ball joint.

  To achieve the above object, according to the first aspect of the present invention, a ball stud having a spherical head and a handle extending from the head, and the head of the ball stud are swingably supported. In a ball joint including a bearing and a housing that supports the bearing by having an opening from which a handle portion of the ball stud protrudes, the ball joint is positioned in a load transmission direction among sliding surfaces of the ball stud head and the bearing. A ball joint is proposed in which the material of the sliding surface is made stronger than the material of the sliding surface located in the other direction.

  According to the second aspect of the present invention, in addition to the structure of the first aspect, the housing and the ball stud are respectively fixed to one and the other of the suspension arm and the knuckle of the vehicle, and the load transmission direction is the suspension arm. A ball joint is proposed which is characterized by being in the longitudinal direction.

  According to the invention described in claim 3, in addition to the structure of claim 1 or claim 2, the material of the sliding surface located in the load transmission direction is nylon, and the sliding surface located in the other direction. A ball joint is proposed in which the material is polyurethane.

  The first bearing 14 of the embodiment corresponds to the bearing of the present invention, the second opening 17c of the embodiment corresponds to the opening of the present invention, and the first sliding surface 21c and the second sliding surface of the embodiment. The surface 22c corresponds to the sliding surface of the present invention.

  According to the configuration of claim 1, of the sliding surfaces between the spherical head of the ball stud and the bearing, the material of the sliding surface located in the load transmission direction is the material of the sliding surface located in the other direction. Since the strength is higher than that of the load transmission direction, the high strength sliding surface located in the load transmission direction increases the durability against bearing sag and wear, while the low strength sliding surface is located in a direction different from the load transmission direction. The frictional resistance can be reduced and the ball stud can be smoothly swung.

  According to the configuration of the second aspect, the housing and the ball stud are fixed to one and the other of the suspension arm and the knuckle, respectively, and the load transmission direction is set to the longitudinal direction of the suspension arm. The load from the road surface can be received by the high-strength sliding surface of the bearing. Thereby, while ensuring the durability of the ball joint, the suspension arm can be smoothly swung to improve the riding comfort of the vehicle.

  According to the structure of Claim 3, since the material of the sliding surface located in the load transmission direction is made of nylon, the strength can be made higher than that of polyurethane which is the material of the sliding surface located in the other direction. .

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below based on examples of the present invention shown in the accompanying drawings.

  1 to 6 show an embodiment of the present invention. FIG. 1 is a longitudinal sectional view of a ball joint, FIG. 2 is a perspective view of an assembled state of a first bearing, and FIG. 4 is a sectional view taken along line 4-4 of FIG. 3, FIG. 5 is a sectional view taken along line 5-5 of FIG. 3, and FIG. 6 is a perspective view of an exploded state of the first bearing.

  As shown in FIG. 1, a vehicle width direction outer end portion of a suspension arm 10 of an automobile and a knuckle 11 that rotatably supports a wheel are swingably connected by a ball joint 12. The ball joint 12 includes a ball stud 13 including a spherical head portion 13a, a tapered rod-like handle portion 13b extending integrally from the head portion 13a, and a male screw portion 13c formed at the tip of the handle portion 13b. The periphery of the head 13 a of the ball stud 13 is covered with a first bearing 14 and a second bearing 15 made of synthetic resin, and the head 13 a of the ball stud 13 swings against the first and second bearings 14 and 15. It is possible to move.

  The tapered rod-shaped handle portion 13b of the ball stud 13 passes through the tapered fixing hole 10a of the suspension arm 10 and is fixed by screwing a nut 16 into a male screw portion 13c protruding from the fixing hole 10a. The substantially cylindrical housing 17 that houses the first and second bearings 14 and 15 includes a housing hole 17a, a first opening 17b, and a second opening 17c, and is press-fitted into the fixing hole 11a formed in the knuckle 11. Fixed.

  In assembling the ball joint 12, the first screw 17c and the handle 13b of the ball stud 13 are penetrated from the first opening 17b of the housing 17 to the second opening 17c, thereby covering the head 13a of the ball stud 13. The second bearings 14 and 15 can be fitted into the storage holes 17a. At this time, since the diameter of the second opening 17c is smaller than the diameter of the second bearing 15, the first and second bearings 14 and 15 do not fall out of the second opening 17c.

  Subsequently, the first opening 17b is closed with a disk-shaped plug 18 and fixed by caulking, whereby the first and second bearings 14 and 15 are held in the housing hole 17a so as not to fall off. At this time, a grease pocket 19 is defined between the central opening 21 a of the first bearing 14, the head 13 a of the ball stud 13, and the plug 18, and the first and second bearings 14 are filled with the grease filled therein. , 15 and the head 13a of the ball stud 13 are lubricated. Then, both ends of the boot 20 that prevent the dust and moisture from entering while allowing the ball stud 13 to swing are fixed to the handle portion 13b of the ball stud 13 and the periphery of the second opening portion 17c.

  Next, the structure of the first bearing 14 will be described in detail with reference to FIGS.

  The first bearing 14 having a cylindrical outer surface and a hemispherical inner surface has an axis L between a relatively soft first half 21 made of polyurethane and a second half 22 made of relatively hard nylon. Composed in the direction. The first half 21 includes a disk-shaped base 21a that contacts the inner surface of the plug 18, and a pair of ball support portions 21b and 21b that rise in the axis L direction from both ends in the diameter direction of the base 21a. The parts 21b and 21b are formed with first spherical sliding surfaces 21c and 21c that are in sliding contact with the head 13a of the ball stud 13, and a grease pocket 19 is formed between the pair of opposing ball support parts 21b and 21b. A circular opening 21d is formed.

  On the other hand, the second half 22 includes an annular connecting portion 22a and a pair of ball support portions 22b and 22b that rise in the axis L direction from both ends in the diameter direction of the connecting portion 22a. Is formed with partial spherical second sliding surfaces 22c, 22c slidably in contact with the head 13a of the ball stud 13, and a circular shape for forming a grease pocket 19 between a pair of opposing ball support portions 21b, 21b. An opening 22d is formed.

  When the first half 21 and the second half 22 are coupled, the end surfaces 21e of the pair of ball support portions 21b, 21b of the first half 21 and the pair of ball support portions 22b, 22b of the second half 22 are combined. The first sliding surfaces 21c and 21c of the first half 21 and the second sliding surfaces 22c and 22c of the second half 22 cooperate with each other so that the end surfaces 22e of the second half 22 are engaged with each other. Thus, a hemispherical sliding surface that contacts the head 13a of the ball stud 13 is formed. The connecting portion 22a of the second half 22 is fitted between the pair of ball support portions 21b, 21b of the first half 21, and the opening 21d of the first half 21 and the opening 22d of the second half 22 are mutually connected. Overlap.

  As is apparent from FIG. 5, the end surfaces 21e of the ball support portions 21b, 21b of the first half 21 are tapered so as to taper toward the base portion 21a, and the ball support portions of the second half 22 are also tapered. The end surfaces 22e of 22b and 22b are also tapered in the same direction. However, since the taper angle of the end surfaces 21e of the ball support portions 21b, 21b of the first half 21 is smaller than the taper angle of the end surfaces 22e of the ball support portions 22b, 22b of the second half 22, When the first half 21 and the second half 22 are coupled, the end surface 21e of the first half 21 and the end surface 22e of the second half 22 that are in contact with each other are pressed into each other with a predetermined allowance. As a result, the first half 21 and the second half 22 can be securely joined.

  When the first half 21 and the second half 22 are combined in this manner, as is apparent from FIG. 3, the end face 21e of the first half 21 and the end face 22e of the second half 22 are 90 °. The four grease grooves 23... Facing the head 13 a of the ball stud 13 are formed on the coupling surface.

  A pair of second sliding surfaces 22c and 22c of the second half body 22 made of hard nylon are arranged in the load transmission direction between the knuckle 11 and the suspension arm 10, that is, in the longitudinal direction of the suspension arm 10 perpendicular to the paper surface of FIG. The pair of first sliding surfaces 21c and 21c of the first half 21 made of polyurethane having lower strength and lower elasticity than the second half 22 made of nylon are arranged in a direction orthogonal to the load transmission direction. .

  Thus, when the suspension arm 10 and the knuckle 11 swing up and down as the vehicle travels, the head 13a of the ball stud 13 supported on the suspension arm 10 side and the first and first supported on the housing 17 on the knuckle 11 side. The two bearings 14 and 15 slide relative to each other. At this time, a large load acts between the suspension arm 10 and the knuckle 11 in the load transmission direction which is the longitudinal direction of the suspension arm 10, but durability such as wear resistance is applied in the load transmission direction of the first bearing 14. Since the second sliding surfaces 22c, 22c of the second half body 22 made of nylon excellent in resistance are arranged, a large load can be supported by the second sliding surfaces 22c, 22c, and durability can be improved. .

  On the other hand, since the first sliding surfaces 21c and 21c of the first half 21 made of low-elasticity polyurethane are arranged in a direction orthogonal to the load transmission direction of the first bearing 14, the first sliding is performed. The surfaces 21c and 21c can smoothly swing the head 13a of the ball stud 13.

  Thus, the material of the second sliding surfaces 22c and 22c of the second half 22 positioned in the load transmission direction between the head 13a of the ball stud 13 and the first bearing 14 is positioned in the other direction. Since the strength is higher than that of the material of the first sliding surfaces 21c and 21c of the first half body 21, durability against the wear of the ball joint 12 and the like by the high-strength second sliding surfaces 22c and 22c located in the load transmission direction. In addition, the low-strength first sliding surfaces 21c and 21c positioned in a direction different from the load transmission direction can reduce frictional resistance and enable smooth swinging of the ball stud 13 to improve riding comfort. .

  The embodiments of the present invention have been described above, but various design changes can be made without departing from the scope of the present invention.

  For example, the ball joint 12 for the suspension arm 10 has been described in the embodiment, but the present invention can be applied to a ball joint for uses other than the suspension arm.

  In the embodiment, the first half 21 of the first bearing 14 is made of soft polyurethane, and the second half 22 is made of hard nylon. However, the material is optional as long as the material satisfies the strength relationship. is there.

  In the embodiment, the ball stud 13 is supported on the suspension arm 10 side and the first and second bearings 14 and 15 are supported on the knuckle 11 side. However, the positional relationship may be reversed.

Vertical section of ball joint A perspective view of the assembled state of the first bearing 3 direction arrow view of FIG. Sectional view taken along line 4-4 in FIG. Sectional view along line 5-5 in FIG. The perspective view of the disassembled state of the first bearing

Explanation of symbols

10 Suspension arm 11 Knuckle 13 Ball stud 13a Head 13b Handle 14 First bearing (bearing)
17 Housing 17c Second opening (opening)
21c First sliding surface (sliding surface)
22c Second sliding surface (sliding surface)

Claims (3)

A ball stud (13) having a spherical head (13a) and a handle (13b) extending from the head (13a);
A bearing (14) for swingably supporting the head (13a) of the ball stud (13);
A housing (17) having an opening (17c) from which the handle (13b) of the ball stud (13) protrudes and supporting the bearing (14);
In ball joints with
Of the sliding surfaces (21c, 22c) between the head (13a) of the ball stud (13) and the bearing (14), the material of the sliding surface (22c) positioned in the load transmission direction is positioned in the other direction. A ball joint characterized by having a higher strength than the material of the sliding surface (21c).   The housing (17) and the ball stud (13) are fixed to one and the other of the vehicle suspension arm (10) and the knuckle (11), respectively, and the load transmission direction is the longitudinal direction of the suspension arm (10). The ball joint according to claim 1, wherein the ball joint is characterized.   The material of the sliding surface (22c) located in the load transmission direction is nylon, and the material of the sliding surface (21c) located in the other direction is polyurethane. The ball joint described.

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