JPH023977Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Field of Application) The present invention relates to a steering link boot seal provided at a connection portion between a rack shaft and a ball joint in a rack and pinion type steering linkage.

(Prior art) Conventionally, in a rack and pinion type steering linkage, a ball joint (inner joint) is attached to the shaft end of the rack shaft, which is moved in the axial direction by engagement with the pinion during steering operation, to prevent it from coming off with a nut. A boot seal with a linear bellows structure is installed between the ball joint and rack housing to prevent water and dust from entering the ball joint and rack shaft.

However, with such conventional steering boot seals, both ends of the boot seal are supported and fixed to the rack housing and ball joint, so the bellows in the center of the boot seal falls down under its own weight, causing the rack housing and ball joint to fall. There was a problem in that the bellows part that fell between the nut and the nut that secures the inlet to the rack shaft would get caught, causing damage to the bellows part during use.

(Purpose of the invention) The present invention was made in view of such conventional problems, and it is an object of the present invention to provide a highly durable steering boot seal having a structure that reliably prevents damage due to falling of the bellows part. With the goal.

(Structure of the invention) In order to achieve this object, the present invention has a rack shaft side bellows part and a ball joint side bellows part whose axis center line is eccentric, and from the rack shaft side bellows part to the ball joint side bellows part. They are connected via tapered bellows parts.

(Embodiment) FIG. 1 is an axial cross-sectional view showing an embodiment of the present invention.

First, to explain the structure, reference numeral 1 is a boot seal of the present invention, which is equipped with a rack shaft-side bellows part 3 centered on the shaft center line 2 on the left side, and centered on the shaft center line 4 eccentric with respect to the shaft center line 2 on the right side. A ball joint side bellows part 5 is provided, and cylindrical tightening fixing parts 6, 8 are formed at the shaft ends of the rack shaft side bellows part 3 and the ball joint side bellows part 5. 8
Annular grooves 7 and 9 into which the clamp ring is fitted are formed on the outside of the ring.

The rack shaft side bellows part 3 and ball joint side bellows part 5 formed on the left and right sides are connected via a tapered bellows part 10 that continues to the straight rack shaft side bellows part 3. A cylindrical tightening fixing part 11 for attaching to the socket part of the ball joint is formed in the continuous part with the ball joint side bellows part 5, and the tightening fixing part 11 has an annular shape on the outside into which a clamp ring is fitted. A groove 12 is formed.

In the boot seal 1 having such an eccentric bellows part, the tightening point formed at the center P of the tightening fixing part 6 formed at the shaft end of the rack shaft side bellows part 3 and the shaft end of the ball joint side bellows part 5 The straight line connecting the center point Q of the fixing part 8 is the easy shaft centerline 30 of the steering linkage to which the boot seal 1 is attached.
give.

FIG. 2 is an explanatory view showing the state in which the boot seal of the present invention shown in FIG. 1 is assembled to the steering linkage.

That is, a fitting groove 18 is formed at the shaft end of the rack housing 13 that accommodates the gear portion of the rack shaft 14, and the fitting groove 18 is provided with a tightening fixing portion of the shaft end of the rack shaft side bellows portion 3 of the boot seal 1. 6 is fitted and fixed by tightening from the outside with a clamp ring 20. A socket 16 of a ball joint 15 is fixed to the tip of the rack shaft 14 by screwing, and is prevented from coming off by tightening a nut 24. A tightening fixing portion 8 formed at the shaft end of the ball joint side bellows portion 5 is fitted into the ball stud 17 taken out from the socket 16, and is tightened and fixed by fitting the clamp ring 21. Further, a tightening fixing portion 11 formed at the continuous portion of the tapered bellows portion 10 and the ball joint side bellows portion 5 is connected to a socket 16.
It is fitted into a fitting groove 19 formed in , and is tightened and fixed by a clamp ring 22 .

Next, the action will be explained.

First, as shown in FIG. 1, the rack shaft side bellows part 3 and the ball joint side bellows part 5 of the boot seal 1.
are connected by the tapered bellows part 10 with eccentric axes 2 and 4, so the internal interval of the rack shaft side bellows part 3 is The upper bellows portion widens toward the ball joint, and the lower bellows portion narrows in internal spacing toward the ball joint.

Therefore, as shown in FIG. 2, as the rack shaft side bellows part 3 moves toward the ball joint 16, the internal distance between the upper bellows part and the rack shaft 14 increases, and by obtaining this large internal distance, the rack shaft Even if the upper side of the shaft side bellows part 3 falls down due to its own weight, it will not fall down to the nut 24.
It is possible to reliably prevent the fallen bellows portion from being caught between the rack housing 13 and the nut 24 and being damaged.

On the other hand, since both sides of the ball joint side bellows part 5 are tightened and fixed by clamp rings 22 and 21, the movement of the ball stud 17 does not affect the rack shaft side bellows part 3.

Furthermore, since a double seal structure is obtained by tightening the clamp rings 21 and 22 on the ball joint 15 side, which is subject to intrusion of water and dust when viewed from the rack shaft 14 side, in the unlikely event that the inside of the bellows part 5 on the ball joint side Even if water or dust enters the rack shaft 14 side, tightening by the clamp ring 22 can reliably prevent water or dust from entering the rack shaft 14 side.

(Effect of the invention) As explained above, according to the invention, the rack shaft side bellows part and the ball joint side bellows part are eccentric, and the rack shaft side bellows part is replaced with a tapered bellows part. Since it is connected to the ball joint side bellows part through the ball joint side, the internal spacing of the upper bellows part, which falls down due to its own weight as it goes towards the ball joint side, is increased, and by obtaining a sufficient internal space, the bellows part Even if the product falls, the bellows part will not get caught between the nut and the rack housing, which secures the ball joint to the rack shaft, and will be damaged, greatly improving the durability of the boot seal. be able to.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of the present invention, and FIG. 2 is an explanatory view showing the state in which the boot seal of the present invention is installed. 1... Boot seal, 2, 4... Shaft center line, 3...
... Rack shaft side bellows part, 5... Ball joint side bellows part, 6, 8, 11... Tightening fixing part, 7,
9, 12... Annular groove, 13... Rack housing, 14... Rack shaft, 15... Ball joint, 16... Socket, 18... Ball stud, 18, 19... Fitting groove, 20, 21 ,22...
...Clamp ring, 30...Rack shaft center line.

Claims (1)

[Scope of utility model registration request] It has a rack shaft side bellows part and a ball joint side bellows part with eccentric axis lines, and the rack shaft side bellows part is connected to the ball joint side bellows part via a tapered bellows part. Steering boot seal.