KR20090029878A - Ball joint having the same shape of the axis of a ball stud as the lip portion of a dust cover - Google Patents

Abstract

The present invention is to improve the sealing effect of the ball joint, in order to further improve the sealing of the upper end of the dust cover in close contact with the shaft portion of the ball stud, the shape of the thread without forming the outer peripheral surface of the shaft portion of the conventional ball stud in a smooth cylindrical surface The lip portion of the dust cover coupled thereto is also configured to form a threaded shape of the shaft portion of the ball stud so that the lip portion of the dust cover coupled thereto is engaged with the shaft portion of the ball stud. Through this configuration, it is possible to prevent foreign substances such as dust and water from penetrating into the ball studs and to prevent leakage of lubricant injected into the ball sheet, thereby improving the performance and life of the ball joint.

Description

Ball joint having the same shape of the axis of a ball stud as the lip portion of a dust cover}

The present invention relates to a ball joint for automobiles, and more particularly to a sealing (sealing) of the ball joint.

Ball joints are widely used as joint means having the function of spherical joints.

1 shows a conventional ball joint structure.

In general, the ball joint protects the ball stud 10, which surrounds the ball stud 10 and the ball stud 10 serving as a center of the joint, and adjusts the friction force acting between the ball stud 10 and the socket 40. The ball sheet 20, the socket stud 10 and the socket 40 for seating the ball sheet 20, and the ball stud 10 are sealed to prevent the ball stud 10 from falling under the socket 20 by the compression load. The dust cover 60 covers the upper portion of the socket to prevent dust from entering the plug 30 and the ball stud 10, and the ball joint is assembled by being pressed into a knuckle or an arm.

In the assembly of the ball joint, the sealing effect to prevent foreign substances such as dust or water from entering the inside of the socket 40 with the ball stud 10 should be assured. Deterioration of the lubricating function of the lubricant injected into the ball sheet and the function of adjusting the friction force of the ball sheet may be deformed, and ultimately, the role of the ball joint as the joint may be degraded. In addition, the ball shaft of the ball stud in the driving state is inclined with a considerable radius in front, rear, left and right, so that the sealing effect can be very degraded if the joint of the ball shaft and the dust cover is not firm. In severe cases, breakage, such as the detachment of the ball stud, may occur.

The ball shaft of the ball stud of the conventional ball joint has a smooth cylindrical surface, and the lip portion of the dust cover in close contact therewith has a screw-shaped cross section, so that the sealing effect is uncertain.

Efforts to improve the sealing effect of the ball joint as described above are also shown in Korean Utility Model Publication No. 20-1998-0042541. In the publication, in order to improve the sealing effect of the ball joint, at least two or more contact ribs are formed on an end contacting the ball axis of the dust cover which is coupled to surround the ball axis in the upper part of the socket of the ball joint, so that the close rib is formed on the ball axis. In close contact with the outer circumferential surface, it is possible to increase the sealing effect. However, the outer circumferential surface of the ball shaft is a smooth cylindrical surface and the close contact ribs are protruding so that the tightness of the seal is not complete (see Fig. 1 (b)).

In addition, Korean Laid-Open Patent Publication No. 2002-0054987 has a coupling groove and a coupling protrusion at a portion where the dust cover is coupled to the socket in order to more firmly seal the dust cover. However, this coupling structure does not consider the adhesion between the shaft cover and the dust cover of the ball stud, but improves only the bonding of the dust cover and the socket.

Accordingly, the present invention has been made to solve this problem.

The technical problem to be solved by the present invention is to make the contact between the ball stud shaft portion of the ball joint and the lip portion of the dust cover in close contact therewith more tightly. Accordingly, to prevent foreign substances and water from entering the ball joint and to prevent leakage of lubricant injected into the ball joint, the purpose of the ball joint is to improve its performance and extend its life.

The present invention provides a ball joint in which the shaft portion of the ball stud and the lip portion of the dust cover coupled thereto have a threaded shape of the ball stud, and the dust cover is engaged with the shaft portion of the ball stud. The shape of the lip is also configured in the same shape as the screw thread.

In the ball joint, the number of threads formed on the shaft portion of the ball stud and the lip portion of the dust cover is constituted by two to three.

According to the present invention, the ball stud shaft portion of the ball joint and the lip portion of the dust cover are in close contact with each other to prevent foreign matter and water from penetrating into the ball joint from the outside and to prevent leakage of lubricant inside the ball joint.

Further, according to the present invention, it is possible to improve the joint function and extend the life of the ball joint due to the improvement of the sealing effect of the ball joint.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the following embodiments are provided to those skilled in the art to fully understand the present invention, and may be modified in various forms, and the scope of the present invention is limited to the embodiments described below. It doesn't happen. Like numbers refer to like elements in the figures.

1 (a) shows a cross-sectional view showing the structure of a general ball joint.

As mentioned, the ball stud 10 is wrapped with a lubricated ball sheet 20, the ball stud 10 and the ball sheet 20 are seated in the socket 40, and the lower end of the socket 40 is plugged. Covered with 30, the lower end of the socket 40 is caulked by bending toward the plug 30, and the upper end of the socket 40 represents a cross section of a general ball joint sealed with a dust cover 60. It can be seen in FIG. 1A that the upper end 63 of the dust cover 60 is in close contact with the shaft 15 of the ball stud 10. That is, the upper end 63 of the dust cover 60 is in close contact with the smooth cylindrical shaft 15 of the ball stud 10.

Figure 1 (b) is two in the shaft portion 15 of the ball stud 10 of the ball joint disclosed in the Republic of Korea Utility Model Publication No. 20-1998-0042541 and the upper end 63 of the dust cover 60 in close contact therewith Is a view showing that the protruding close contact ribs 17 and 18 are formed.

In the case of the ball joint shown in Figs. 1 (a) and 1 (b), the shaft portion 15 of the ball stud consists of a smooth cylindrical surface, so that the upper end 63 of the dust cover 60 is firmly there without any gap. It is hard to be closely attached. In particular, a gap is more likely to occur due to the movement of the shaft portion 15 of the ball stud 10 during the driving of the ball joint. This is because the shaft portion 15 of the ball stud 10 moves in an elliptical orbit while driving the ball joint.

2 shows the upper end 630 of the dust cover 60 and the shaft part 150 of the ball stud 10 according to the invention.

The upper end portion 630 of the dust cover 60 and the shaft portion 150 of the ball stud 10 are configured in a screw shape to be engaged with each other. A portion of the shaft portion 150 of the ball stud 10 is in close contact with the upper end portion 630 of the dust cover 60 is configured to have two to three threads rather than a smooth cylindrical shape of the dust cover 60 The upper end portion 630 is also configured to have a thread of the same shape to be engaged with the thread.

2 shows the state before the upper end 630 of the dust cover 60 and the ball shaft 150 are engaged, and the right side of FIG. 2 shows the upper end 630 and the ball shaft 150 of the dust cover 60. This is in the engaged state.

Through the engagement of both threads the sealing of the ball joint by the dust cover can bring about an improved effect.

1 (a) is a cross-sectional view showing the structure of a general ball joint.

Fig. 1 (b) is a cross-sectional view showing an upper end portion of a dust cover in close contact with the shaft portion of a conventional ball stud.

Figure 2 is a cross-sectional view showing a cross section of the shaft of the ball stud and the upper end of the dust cover in engagement with it according to the invention.

<Explanation of symbols for the main parts of the drawings>

10: ball stud 15, 150: shaft portion

20: ball seat 30: plug

40: socket 60: dust cover

63, 630: upper part of the dust cover

Claims (2)

In the ball joint, the shape of the lip portion of the dust cover which is formed by threading the axial portion of the ball stud so as to be in close contact with the axial portion of the ball stud and the lip portion of the dust cover coupled thereto is also engaged with the axial portion of the ball stud. A ball joint in which the shaft portion of the ball stud constituting the same shape as the thread has the same shape as the lip portion of the dust cover. The method of claim 1, A ball joint having the same shape as the lip portion of the dust cover, wherein the axial portion of the ball stud constituting the number of two to three threads formed on the axial portion of the ball stud and the lip portion of the dust cover.

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