JPH09166129A - Dust cover structure of ball joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reliably ensure sealing ability of a dust cover even during in the cold state. SOLUTION: A plurality of protrusion parts 74 protruded to the knuckle arm 22A side are formed on the part, positioned facing the lower end of the knuckle arm 22A, of a dust cover 46. Thereby, during bounding and rebounding of a suspension, deposited ice is crushed by the protrusion parts 74. Thus, deposited ice is prevented from growing and forcibly pressing downward the upper end part of a dust cover 46. As a result, sealing ability of the upper end part of the dust cover 46 is reliably ensured even during in the cold state.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dust cover structure applied to a ball joint.

[0002]

2. Description of the Related Art As an example of the structure of a conventional ball joint, the actual construction of Shokai 62-1
The configuration disclosed in Japanese Laid-Open Patent Publication No. 74117 can be mentioned, which will be briefly described below.

FIG. 7 shows a ball joint 100 used for an automobile suspension. The ball joint 100 is a ball stud 1 including a shaft portion 102A having a male screw formed on the peripheral surface of the tip portion and a hemispherical spherical portion 102B formed at the lower end portion of the shaft portion 102A.
02. Shaft 102 of ball stud 102
A knuckle arm 104 of a steering knuckle is inserted into the upper end of A and is fixed by a nut (not shown). In addition, the spherical portion 102 of the ball stud 102
B is housed in a cylindrical socket 106 attached to the tip of a suspension arm (not shown). A cover 108 is attached to the lower end of the socket 106, and the spherical portion 102B of the ball stud 102 is pressed and urged via the ball seat 112 by the urging force of the compression coil spring 110 housed in the cover 108. .

A dust cover 114 made of an elastic material such as rubber and filled with grease is disposed between the upper end of the socket 106 and the knuckle arm 104. The lower end of the dust cover 114 is fixed to the upper end of the socket 106 by an annular reinforcing ring 116. Further, the upper end of the dust cover 114 is locked by a rubber seal member 118 arranged at a predetermined position of the shaft portion 102A of the ball stud 102. The seal member 118 is bonded to the retainer 120 fixed to the shaft 102A of the ball stud 102 at a predetermined position.

According to the above structure, since the upper end of the dust cover 114 is elastically locked to the seal member 118 and pressed against the lower end surface of the knuckle arm 104, the sealing performance of the upper end of the dust cover 114 is improved. This is ensured and grease leakage and rainwater intrusion are prevented.

By the way, when cold, the lower end surface of the knuckle arm 104 and the dust cover 114 adjacent to the lower end surface of the knuckle arm 104.
Ice may adhere to the upper edge of the. In particular, the lower end surface of the knuckle arm 104 is often a cutting (metal) surface by cutting in order to increase the degree of close contact with the upper end portion (sealing portion) of the dust cover 114 and maintain high sealing performance. Therefore, icing is remarkable at this portion, and depending on the degree of growth of ice, icing is also remarkable at the portion from the cutting surface to the upper end of the dust cover 114 which is adjacent to the cutting surface. Then, when the ice grows as described above, the upper end portion of the dust cover 114 is pressed downward, and the sealing surface of the upper end portion is deformed. In addition, when the suspension repeatedly bounces and rebounds in the ice-bound state, the attached ice strongly presses the upper end portion of the dust cover 114, which also deforms the sealing surface of the upper end portion.
As a result, there is a problem that the sealing performance of the upper end portion of the dust cover 114 deteriorates.

In consideration of the above facts, an object of the present invention is to obtain a dust cover structure of a ball joint which can surely secure the sealing performance of the dust cover even in cold weather.

[0008]

According to a first aspect of the present invention, a spherical portion is housed in a bearing portion provided at an end portion of a suspension arm, and a shaft portion extending from the spherical portion is a steering knuckle. A dust cover structure that is applied to a ball joint including a ball stud connected to a knuckle arm of, and covers a portion between the bearing portion and the knuckle arm in the ball stud,
The knuckle arm side portion of the dust cover is provided with ice crushing means for crushing the ice that has projected to the knuckle arm side and iced.

According to the second aspect of the present invention, the spherical portion is housed in the bearing portion provided at the end of the suspension arm, and the shaft portion extending from the spherical portion is connected to the knuckle arm of the steering knuckle. Applied to a ball joint including a ball stud, and having a dust cover structure that covers a portion between the bearing portion and the knuckle arm in the ball stud, and the knuckle arm side portion in the dust cover. Is provided with an icing prevention means for covering the surface facing the dust cover to prevent icing on the facing surface.

According to the first aspect of the present invention, at the time of bouncing and rebounding of the suspension, the ball stud swings in accordance with this movement and the dust cover also deforms. Along with this deformation, the ice breaking means provided on the knuckle arm side portion of the dust cover and protruding toward the knuckle arm side moves toward the knuckle arm. For this reason, the ice frosted on the portion from the knuckle arm to the dust cover during cold is hit by the ice crushing means and crushed. That is, in the present invention, although icing is allowed, crushing the icing ensures the sealing property of the dust cover.

According to the second aspect of the present invention, the icing prevention means is provided in the portion of the dust cover on the knuckle arm side, and the icing prevention means covers the surface of the knuckle arm facing the dust cover. Therefore, even if, for example, the facing surface of the knuckle arm is a cutting (metal) surface due to cutting work and is in a state of easily icing, icing does not occur. That is, in the present invention, the sealing property of the dust cover is secured by preventing the icing itself.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION

[First Embodiment] A first embodiment will be described below with reference to FIGS.
An embodiment will be described. The first embodiment corresponds to an embodiment of the present invention described in claim 1.

FIG. 4 is an overall perspective view of the front suspension of the automobile. As shown in this figure, a suspension member 10 is arranged at the center of the front suspension, and both longitudinal ends of the suspension member 10 and left and right wheels 12 are connected by an L-shaped lower arm 14. ing.

More specifically, the front end and the rear end of the lower arm 14 on the inner end side are connected to the outer end of the suspension member 10 via bushes 16 and 18. Further, as shown in FIG. 3, the outer end portion of the lower arm 14 is
It is connected to the lower end of a steering knuckle 22, which is a wheel support, via a lower ball joint 20.

The lower end of the shock absorber 24 is attached to the bracket 26 at the upper end of the steering knuckle 22.
Fixed through the steering knuckle 22
An axle hub 30 is rotatably supported by an angular ball bearing 28 at the axial center of the shaft. Axle hub 30
The shaft portion 32A of the axle 32 is fixed by a nut 34, and a disc rotor 38 and a disc wheel (not shown) that form a main portion of the disc brake device together with a caliper 36 are fastened together by a hub bolt 40 and a hub nut (not shown). Has been done.

FIG. 1 and FIG. 2 show enlarged views centering on the lower ball joint 20 in the above-mentioned structure. As shown in these figures, the lower ball joint 20 includes a bearing portion 42, a ball stud 44,
The dust cover 46 is included and will be described below in this order.

The bearing portion 42 is a plate-like flange portion 42A fixed to the outer end portion of the lower arm 14 with bolts 48 and 50.
And a cylindrical socket 42B integrally provided on the outer end of the flange 42A.
A bottom wall 52 is fixed to the bottom of the socket 42B,
As a result, the lower end of the socket 42B is closed.
Further, on the inner peripheral surface of the socket 42B, a resin-made cylindrical ball seat 54 and dish-shaped ball seat 56 are arranged in a superposed state.

The ball stud 44 comprises a spherical portion 44A provided at the lower end portion and a shaft portion 44B extending from the spherical portion 44A along the axis, and is manufactured by forging. ing. The spherical portion 44A of the ball stud 44 has the ball seats 54, 5 of the socket 42B.
It is housed in 6 so as to be rotatable and swingable. Further, the shaft portion 44B of the ball stud 44 has a steering knuckle 2
The second knuckle arm 22A is inserted into an insertion hole 58 formed in the knuckle arm 22A. In this state, the ball stud 44 is fixed to the knuckle arm 22A by screwing the nut 60 into the tip portion of the shaft portion 44B and inserting and locking the rotation stop pin 62.

The shaft portion 44B of the ball stud 44 described above.
Upper end of socket 42B and knuckle arm 22 at
A cylindrical dust cover 46 made of an elastic material (rubber, resin, etc.) is disposed between the lower end surface of A and the lower end surface. The dust cover 46 has a dustproof function, and may or may not contain grease therein due to the relationship with the ball seats 54 and 56.

The lower end portion of the dust cover 46 described above is fitted into the groove 64 formed on the outer peripheral surface of the upper end portion of the socket 42B, and is fixed to the socket 42B by the annular reinforcing ring 66 in this state. In addition, the dust cover 46
The upper end portion of is projected outward in the radial direction (hereinafter, this portion is referred to as "outer peripheral lip portion 46A"). An annular seal lip portion 68 made of an elastic material (rubber, resin, etc.) is disposed inside the outer peripheral lip portion 46A. Further, the outer peripheral lip portion 46A and the seal lip portion 68
A ring-shaped insert 70 is disposed between and, so that the seal lip portion 68 is pressed against the outer peripheral surface of the shaft portion 44B of the ball stud 44. The seal lip portion 68 and the insert 70 are preliminarily integrated by being vulcanized and bonded at the time of molding the dust cover 46.

Further, the locking position of the upper end of the dust cover 46 having the above-mentioned structure is determined by the shaft portion 44B of the ball stud 44.
The upper end of the dust cover 46 follows the movement of the suspension so that the upper end of the dust cover 46 is integrally formed on the peripheral surface of the intermediate portion of the ball stud 44 and the peripheral surface of the shaft portion 44B of the ball stud 44 (under the knuckle arm 22A). The part from the end surface to the protrusion 72) is slid in the axial direction.

Here, on the outer peripheral surface on the upper end side of the dust cover 46 (the portion of the dust cover 46 on the knuckle arm 22A side and facing the knuckle arm 22A), a plurality of projections 74 as ice breaking means are provided. Are formed. These protrusions 74 are provided on the knuckle arm 22.
The dust cover 4 is projected toward the lower end surface side of A.
6 is integrally formed at the time of molding. Therefore, the protrusion 74
Is the same as the material of the dust cover 46, and is made of an elastic material (rubber, resin, etc.).

Next, the operation and effect of this embodiment will be described. In the cold state, as shown in FIG. 1, icing (shown as an arrow P portion in FIG. 1) occurs in a portion from the lower end surface of the knuckle arm 22A to the outer peripheral surface of the upper end portion of the dust cover 46. There is.

In this case, according to this embodiment, the ice that has landed as follows is crushed. That is, when the suspension bounces and rebounds, the ball stud 44 swings around the spherical portion 44A as a fulcrum according to this movement. For example, at the time of rebound, as shown in FIG. 2, the stud bolt 44 swings, and along with this, the dust cover 46 is also compressed and deformed. Therefore, the plurality of protrusions 7 provided on the outer peripheral surface on the upper end side of the dust cover 46.
4 moves to the lower end surface side of the knuckle arm 22A. Therefore, the projected ice 74 hits the iced ice and breaks it. In the above description, the crushed ice at the time of rebound was described, but the same effect can be obtained at the time of bound.

As described above, in the present embodiment, a plurality of protrusions 74 projecting toward the knuckle arm 22A side are formed in the portion of the dust cover 46 facing the lower end surface of the knuckle arm 22A, and the suspension is bound and rebounded. The deformation of the dust cover 46 is used to break the ice that has been iced, so that it is possible to prevent the ice that has been iced from growing and pressing the upper end of the dust cover 46 downwardly. Therefore, it is possible to reliably maintain the sealing performance of the upper end portion of the dust cover 46 when cold.

Further, according to this embodiment, since the plurality of protrusions 74 are formed on the outer peripheral surface on the upper end side of the dust cover 46, the rigidity of the portion of the dust cover 46 where the protrusions 74 are formed is increased. be able to. For this reason, the reaction force when the protrusion 74 hits the iced ice or the reaction force when the protrusion 74 abuts the lower end surface of the knuckle arm 22A on the dust cover 46 when the ice is not iced on the dust cover 46. Even if it works, since the dust cover 46 has high rigidity as described above, it can sufficiently withstand this reaction force. Therefore, the durability of the dust cover 46 can be guaranteed.

In this embodiment, the dust cover 46 is used.
A plurality of protrusions 74 on the outer peripheral surface on the upper end side of the dust cover 4
Although it is formed integrally with 6, the dust cover 4 is not limited to this.
The bottom of the protrusion may be embedded in the outer peripheral surface on the upper end side of 6 to project the tip from the surface. For example, it is possible to embed a relatively hard protrusion by insert molding or the like when molding the dust cover 46. In this case, the projection to be buried needs to be hard enough to break ice, but preferably has a hardness that does not damage the lower end surface of the knuckle arm 22A. [Second Embodiment] The second embodiment will be described below with reference to FIGS. 5 and 6. The second embodiment corresponds to an embodiment of the present invention described in claim 2. Further, regarding the same components as in the first embodiment,
The same numbers are assigned and the description thereof is omitted.

While the first embodiment described above has a structure in which icing is allowed and then the ice is crushed, the second embodiment is characterized in that icing is prevented.

That is, in this embodiment, FIG. 5 and FIG.
As shown in FIG.
0A largely extends outward in the radial direction (the surface direction of the lower end surface of the knuckle arm 22A), and the extended outer peripheral lip portion 80A causes the cutting surface S (see FIG. 5) at the lower end surface of the knuckle arm 22A. The whole area is covered (covered) in a contact state. The cutting surface S corresponds to "a surface of the knuckle arm facing the dust cover", and the outer peripheral lip portion 80A corresponds to "ice accretion preventing means".

The cutting surface S of the knuckle arm 22A will be described. Normally, the lower end portion of the knuckle arm 22A has a high degree of close contact with the outer peripheral lip portion 80A, which is the sealing portion of the dust cover 80, to enhance the sealing performance. It is cut by cutting to maintain it. The area cut at this time is the area indicated by S, and since this cutting surface S is a metal cutting surface, icing is most likely to occur in this portion. In general, icing first occurs on the cutting surface S (initial icing), and then the iced ice grows on the upper end portion of the dust cover 46 as shown in FIG. 1 of the above-described embodiment. Therefore, the upper end of the dust cover 46 is strongly pressed downward.

According to the above construction, when the suspension bounces and rebounds, the ball stud 44 swings around the spherical portion 44A as a fulcrum according to this movement. For example,
At the time of rebound, as shown in FIG. 6, the stud bolt 44 swings, and accordingly, the dust cover 80 is also compressed and deformed. However, in the present embodiment, the cutting surface S of the knuckle arm 22A is covered by the outer peripheral lip portion 80A of the dust cover 80 regardless of bounding and rebounding. Therefore, the cutting surface S is not exposed and the initial icing can be prevented. Then, by preventing the initial icing, it is possible to eliminate a phenomenon such as ice growth.

As described above, in the present embodiment, the outer peripheral lip portion 80A of the dust cover 80 extends radially outward (the surface direction of the lower end surface of the knuckle arm 22A) and the cutting surface S ( (See Figure 5)
Since it is configured to cover, it is possible to prevent icing itself. Therefore, it is possible to reliably maintain the sealing property of the upper end portion of the dust cover 80 when cold.

In this embodiment, the outer peripheral lip portion 80A of the dust cover 80 covers the entire area of the cutting surface S to ensure the prevention of icing, but the entire area of the cutting surface S is not necessarily the outer periphery. It is not necessary to cover with the lip portion 80A. That is, when the range of the cutting surface S is wider than the upper end portion of the dust cover 80 as compared with the case shown in FIG. 5, a range in which the iced ice does not strongly press the upper end portion of the dust cover 80 (dust (A range that does not affect the cover 80) also occurs. Therefore, even in such a case, it is not necessary to cover the entire area of the cutting surface S with the outer peripheral lip portion 80A,
In short, the range where the dust cover 80 may be strongly pressed by the iced ice, that is, the “face of the knuckle arm 22A facing the dust cover 80” of the cutting surface S is covered by the outer peripheral lip portion 80A. Good.

Further, in the above-mentioned embodiment, the present invention is applied to the lower ball joint 20 of the front suspension, but the present invention is not limited to this, and the present invention may be applied to an upper ball joint.

[0035]

As described above, in the dust cover structure of the ball joint according to the present invention as set forth in claim 1, the knuckle arm side portion of the dust cover crushes the ice that has projected to the knuckle arm side and frosted. Since the ice crushing means is provided, the ice crushing is allowed, but the ice crushing can be crushed, which has an excellent effect that the sealing property of the dust cover can be surely secured even in the cold state.

In the ball joint dust cover structure according to the present invention as set forth in claim 2, the knuckle arm side portion of the dust cover covers a surface of the knuckle arm facing the dust cover, and icing is applied to the facing surface. Since the icing preventing means for preventing the icing is provided, it is possible to prevent the icing itself, which has an excellent effect that the sealing property of the dust cover can be surely secured even in the cold state.

[Brief description of the drawings]

FIG. 1 is an enlarged sectional view of an essential part of a ball joint provided with a dust cover according to a first embodiment.

FIG. 2 is a cross-sectional view corresponding to FIG. 1, showing a state where ice is crushed by a protrusion of the dust cover shown in FIG.

FIG. 3 is a cross-sectional view of essential parts showing the ball joint shown in FIG. 2 and its peripheral configuration.

FIG. 4 is a perspective view of a front suspension using the ball joint according to the present embodiment.

FIG. 5 is an enlarged sectional view of an essential part of a ball joint including a dust cover according to a second embodiment.

6 is a cross-sectional view corresponding to FIG. 5, showing a state of the dust cover shown in FIG. 5 at the time of rebound.

FIG. 7 is a cross-sectional view showing a configuration of a ball joint according to a conventional example.

[Explanation of symbols]

 14 Lower Arm (Suspension Arm) 20 Lower Ball Joint 22 Steering Knuckle 22A Knuckle Arm 42 Bearing Part 44 Ball Stud 44A Spherical Part 44B Shaft Part 46 Dust Cover 74 Projection (Ice Crushing Means) 80 Dust Cover 80A Peripheral Lip Part (Ice Blocking Means) )

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroyuki Koba 1 Toyota-cho, Toyota-shi, Aichi Toyota Motor Co., Ltd.

Claims (2)

[Claims] 1. A structure in which a spherical portion is housed in a bearing portion provided at an end portion of a suspension arm, and a shaft portion extending from the spherical portion includes a ball stud connected to a knuckle arm of a steering knuckle. It has a dust cover structure applied to a ball joint that covers the part between the bearing part and the knuckle arm of the ball stud, and the knuckle arm side part of the dust cover has projected and iced to the knuckle arm side. The ball cover dust cover structure is characterized in that an ice breaking means for breaking ice is provided. 2. A ball stud, wherein the spherical portion is housed in a bearing portion provided at an end portion of the suspension arm, and a shaft portion extending from the spherical portion includes a ball stud connected to a knuckle arm of a steering knuckle. The dust cover structure is applied to the ball joint that covers the part between the bearing part and the knuckle arm of the ball stud, and the knuckle arm side part of the dust cover has a surface facing the dust cover. A dust cover structure for a ball joint, characterized in that it is provided with an icing blocking means for blocking icing on the facing surface.