JP2509432Y2 - Flexible boot device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Industrial field For example, a mechanical boot element of an automobile is equipped with a flexible boot made of an elastic material such as rubber or synthetic resin. From the outside, or prevents the lubricant around the mechanical elements from leaking to the outside. In this case, one end of the flexible boot is fitted to a reciprocating shaft, which is one mechanical element of the steering mechanism, that is, a tie rod.

The present invention relates to, for example, a flexible boot device including the flexible boot and the reciprocating shaft as described above.

That is, in more detail, according to the present invention, at least one end in the axial direction of the bellows portion is provided with an end wall portion which is inclined outward in the axial direction and radially inward, and the side of the one end of the bellows portion is provided. And a fitting portion to the mechanical element is provided on each of the other end side, and the fitting portion on the one end side has a flexible boot provided at a substantially central position of the end wall portion, and has a circumferential groove. And a reciprocating shaft that constitutes one of the mechanical elements, the fitting portion at the one end side is fitted in the circumferential groove, and the wall thickness of the end wall portion is equal to that of the bellows portion. It gradually increases from the position to the position of the fitting portion on the one end side, and when the reciprocating shaft moves until the bellows portion contracts by a predetermined value or more, the end wall portion projects inward in the axial direction of the bellows portion. The present invention relates to a flexible boot device configured to be inverted so that

2. Description of the Related Art Conventionally, there is known a flexible boot mounted on a rack-pinion type steering mechanism of an automobile having a structure shown in FIG. That is, in this flexible boot, at least one end (the right end in FIG. 5) in the axial direction of the bellows portion 1 is provided with an end wall portion 4 which is inclined outward in the axial direction and inward in the radial direction. In the structure in which the fitting portions 2 and 3 are provided on the one end side and the other end side, respectively, and the fitting portion 2 on the one end side is provided substantially at the center position of the end wall portion 4. I'm running. The fitting portion 2 is fitted to a tie rod 5 connected to a tire (not shown), and the fitting portion 3 is fitted to an end portion of a housing 7 that houses a pinion gear. The end wall portion 4 extends from the connecting portion with the bellows portion 1 toward the fitting portion 2 so as not to be damaged when the flexible boot is repeatedly expanded and contracted and swung in response to the operation of the steering mechanism. The wall thickness is gradually increasing. In FIG. 5, 6 is a rack shaft, 8 is a ball joint, 9 is a shaft connecting a pinion gear and a handle shaft (not shown), and 10 and 11 are tightening bands.

In the steering mechanism, the rack shaft 6 reciprocates left and right as the pinion gear rotates in response to the steering operation, and the bellows portion 1 of the flexible boot expands and contracts according to the reciprocal movement. And
When the rack shaft 6 moves to the vicinity of the leftmost position and the bellows portion 1 is contracted most, and the force pressing the fitting portion 2 to the left reaches a predetermined value or more, the end wall portion 4 moves the bellows portion. The state shown in FIG. 6 is reversed so as to be convex inward in the axial direction of 1. The reason why the end wall portion is configured to be inverted in this way is to shorten the total length of the flexible boot with respect to a predetermined moving stroke length of the rack shaft 6 in the left-right direction. That is, when the end wall portion 4 is not inverted and is always convex outward in the axial direction as shown in FIG. 6, the length of the flexible boot with respect to the moving stroke length of the rack shaft 6 becomes large. It will end up.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention In the above-mentioned prior art, when the end wall portion 4 is in the state shown in FIG. 5 which is not inverted, the fitting portion 2 is tightly sealed to the tie rod 5 as shown in FIG. Is fitted to.
However, when the end wall portion 4 is inverted as shown in FIG. 6, the end wall portion 4 is bent at the connecting portion a with the fitting portion 2 as shown in FIG. A gap b is formed between the portion 2 and the tie rod 5, and the sealing performance is impaired. Further, in accordance with the operation of the steering mechanism, the state of FIG. 8 in which the gap b is formed,
As the state of FIG. 7 in which the gap b is not formed is repeated, the vicinity of the connecting portion a is worn by rubbing with the side surface of the boot mounting groove 5a of the tie rod 5, and the fitting portion 2 is tie rod. However, there is a problem in that it may be dislocated from the boot mounting groove 5a of No. 5 and fall off.

Means for Solving the Problems In order to solve the above-mentioned problems, in the present invention, the outer surface of the end wall portion has a gentle inclined portion extending outward in the radial direction over a small distance from the position of the fitting portion. , A steep slope extending from the tip of the gentle slope to the bellows, or a steep slope in which the inner surface of the end wall extends radially outward over a small distance from the position of the fitting. And a gentle slope extending from the tip of the steep slope to the bellows, the end wall bends at the boundary between the steep slope and the gentle slope when the end wall is inverted. Is configured as follows.

In the present specification, an inclined portion having a small inclination angle with respect to the axis of the bellows portion is referred to as a “slowly inclined portion” and an inclined portion having a large inclination angle is referred to as a “steep inclined portion”.

Action In the flexible boot device of the present invention, the end wall portion is connected to the fitting portion when the flexible boot is inverted.
The end wall portion is bent at the boundary portion which is separated from the connection portion by a small distance outward in the radial direction of the bellows portion without bending to produce the gap b in FIG. To do.

Embodiment FIG. 1 and FIG. 2 are views similar to FIG. 7 and FIG. 8 showing an essential part of a flexible boot device of a first embodiment of the present invention. In the flexible boot in this flexible boot device, the outer surface of the end wall portion 4 provided at one end of the bellows portion 1 in the axial direction is radially outward from the position of the fitting portion 2 to the tie rod 5 over a small distance. Gentle slope 4a
And a steep slope extending from the tip of the gentle slope 4a to the bellows 1.
4b, and other configurations are the same as those of the prior art described with reference to FIGS. 5 to 8. The reciprocating shaft 5 has a circumferential groove, and the fitting portion 2 is fitted in the circumferential groove. Further, the wall thickness of the end wall portion 4 gradually increases from the position of the bellows portion 1 to the position of the fitting portion 2, but this configuration makes the rigidity of the radially outer portion of the end wall portion 4 in the radial direction. It is gradually smaller than that of the inner portion so that the end wall portion 4 can be smoothly inverted, which is also used in the above-mentioned conventional technique.

In the flexible boot device of the first embodiment, the fitting portion 2 provided on the end wall portion 4 moves inward in the axial direction of the bellows portion 1 by a predetermined value or more in accordance with the operation of the steering mechanism. Then, when a force of a predetermined value or more is applied to the end wall portion 4, the end wall portion 4 bends at the boundary portion 4c between the gentle slope portion 4a and the steep slope portion 4b as shown in FIG. Then, the end wall portion 4 is inverted so as to be convex inward in the axial direction of the bellows portion. Therefore, when the end wall portion 4 is inverted, the fitting portion 2 is
It is maintained in a tightly fitted state with the tie rod 5 in a sealed state.

In the first embodiment, the gently sloping portion 4a is provided on the outer surface of the end wall portion 4.
Although a steep slope 4b is provided, as in the second embodiment shown in FIG. 3, the inner surface of the end wall part 4 extends over a small distance from the position of the fitting part 2 to the tie rod 5. A steep slope portion 4d extending outward in the direction and a gentle slope portion 4e extending from the tip of the steep slope portion 4d to the bellows portion 1 are provided, and the end wall portion 4 is shown in FIG. 4 when the end wall portion 4 is inverted. The steep slope 4d and the gentle slope as shown
You may make it bend | fold in the boundary part 4f with 4e.

Further, the outer surface of the end wall portion 4 has a gentle sloped portion as in the first embodiment.
At the same time as providing 4a and a steep slope portion 4b, a steep slope portion 4d and a gentle slope portion 4e as in the second embodiment are provided on the inner surface of the end wall portion 4, and the boundary portions 4c and 4f have a diameter of the end wall portion 4. It is also possible that the end wall portions 4 are bent at the positions of these boundary portions at the time of reversing so that they are located at substantially the same position in the direction.

The flexible boot of the illustrated embodiment has a bellows portion 1
Although the end wall portion 4 as described above is provided only at one end in the axial direction, the end wall portions may be provided at both ends in the axial direction of the bellows portion depending on the application of the flexible boot.

EFFECTS OF THE INVENTION As is apparent from the above, in the flexible boot device of the present invention, it is possible to avoid the inconvenience caused by the gap between the fitting portion and the mechanical element when the end wall portion of the flexible boot is inverted. Play.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a part of an end wall portion and a fitting portion in a flexible boot of a flexible boot device according to a first embodiment of the present invention in a state where the fitting portion is fitted to a tie rod of a steering mechanism. FIG. 2 shows a state in which the end wall portion is inverted, a sectional view similar to FIG. 1, and FIGS. 3 and 4 show a flexible boot of a flexible boot device according to a second embodiment of the present invention. A view similar to FIGS. 1 and 2, showing a part of the end wall portion and the fitting portion, FIG. 5 is a view showing a state in which a conventional flexible boot is mounted on a steering mechanism, and FIG. 6 is FIG. 5 is a partial sectional view showing a state in which the end wall portion of the flexible boot of FIG. 5 is inverted, and FIGS. 7 and 8 show a part of the end wall portion and the fitting portion of the conventional flexible boot. It is a sectional view similar to FIG. 1 and FIG. . 1 ... Bellows part, 2, 3 ... Fitting part, 4 ... End wall part, 4a, 4e ...
… Slightly sloping parts, 4b, 4d …… Steep slopes, 4c, 4f …… Boundary parts.

Claims (2)

(57) [Scope of utility model registration request] 1. An end wall portion that is inclined outward in the axial direction and inward in the radial direction is provided at at least one end in the axial direction of the bellows portion, and each of the one end side and the other end side of the bellows portion is provided. And a flexible boot in which a fitting portion on the mechanical element is provided, and a fitting portion on the one end side is provided at a substantially central position of the end wall portion, and a peripheral groove having a peripheral groove. A reciprocating shaft constituting one side, the fitting portion on the one end side is fitted in the circumferential groove, and the wall thickness of the end wall portion is from the position of the bellows portion to the one end side. It gradually increases to the position of the fitting portion, and when the reciprocating shaft moves until the bellows portion contracts by a predetermined value or more, the end wall portion is inverted so as to be convex inward in the axial direction of the bellows portion. In the flexible boot device configured as described above, the outer surface of the end wall portion has a position of the fitting portion. Has a gently sloping portion that extends outward in the radial direction over a small distance from the sloping portion, and a steeply sloping portion that extends from the tip of the gently sloping portion to the bellows portion. A flexible boot device, characterized in that it is configured to bend at the boundary between the inclined portion and the steeply inclined portion. 2. The bellows portion is provided with an end wall portion which is inclined outward in the axial direction and inward in the radial direction, at least at one end in the axial direction of the bellows portion, and each of the one end side and the other end side of the bellows portion. And a flexible boot in which a fitting portion on the mechanical element is provided, and a fitting portion on the one end side is provided at a substantially central position of the end wall portion, and a peripheral groove having a peripheral groove. A reciprocating shaft constituting one side, the fitting portion on the one end side is fitted in the circumferential groove, and the wall thickness of the end wall portion is from the position of the bellows portion to the one end side. It gradually increases to the position of the fitting portion, and when the reciprocating shaft moves until the bellows portion contracts by a predetermined value or more, the end wall portion is inverted so as to be convex inward in the axial direction of the bellows portion. In the flexible boot device configured as described above, the inner surface of the end wall portion has a position of the fitting portion. Has a steep slope extending radially outward from the end of the steep slope, and a gentle slope extending from the tip of the steep slope to the bellows. A flexible boot device, characterized in that it is configured to be bent at a boundary portion between an inclined portion and a gently inclined portion.