JP2606351Y2 - Steering resin boots - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a mounting portion for mounting a steering resin boot incorporated in an end portion of a steering device to a mating part. Further More specifically, this invention is as pinching it to attach the end cover having a head comprising a blanking over Tsu locking annular projection polyhedral the mounting portion of the mating component for attaching the resin boots irregularities boots Related to the structure to be fixed.

[0002]

2. Description of the Related Art Between a gear housing of a steering apparatus of a rack and pinion type of an automobile and a tie rod connected to a tip of a rack shaft which enters and exits through a spherical joint, these are protected from dust and muddy water. Boots are attached for it.

Conventionally, rubber boots have been generally made of rubber, but recently it has been proposed to use lightweight and inexpensive resin. However, when the resin boot is compressed and pulled by the reciprocating motion of the rack shaft and the swing of the tie rod, it is inferior in flexibility to the rubber boot when it is bent, and thus cannot be fixed sufficiently with the fixing band alone. There is.

[0004] Therefore, conventionally, either this fitting the mounting portion of the boot is provided with grooves on an end portion for attaching the boot of the gear housing, some have is provided a blanking over tool locking annular projection (flange) By engaging an annular recess formed in the mounting portion of the boot with this, the fixing in the axial direction is strengthened. Here, when fixing the boot only by the latter of the probe over Tsu locking annular projection, in order to prevent axial movement of the boot, between the annular projection boot locking of the end cover with the mounting of the boot end A boot-side locking projection sandwiched between the bellows is formed on the bellows side. The boot-side locking projection allows the thickness of the cylinder to be controlled during blow molding and maintains the strength of the positioning projection by forming a circular cylinder between the mounting part and the bellows part. It is formed by depressing several places in the circumferential direction.

On the other hand, grooves bush over tool engaging the gear housing
Since it is not easy to process the annular projection integrally, it has been considered to form only the boot engaging annular projection separately and screw it into the gear housing. For example, as shown in FIG. 3, prepared end cover 103 forming the blanking over tool locking annular collision <br/> force 101 and screws (not shown) together, which screw hole of the gear housing 104 ( and it is provided an annular projection for blanking over tool engaging the end for attaching the boot 105 of the gear housing 104 by screwing the not shown). At this time, the end cover 103 needs a polyhedron, for example, a hexagonal head 102 projecting into the boot 105 to be screwed into the gear housing 104. Therefore, resin boots 10
5, the annular projection 101 for locking the boot of the end cover 103
The boot-side locking projection 106 of the cylindrical portion 108 that sandwiches the
It is necessary to have a size that does not interfere with the hexagonal head 102 of the end cover 103.

[0006]

[Problem to be Solved by the Invention] However, the cylindrical portion 1
08, several boot-side locking protrusions 106
There is a problem in that the size is limited to a size such that the inner peripheral surface 107 does not interfere with the hexagonal head 102 of the end cover 103 when the boot is assembled. Moreover, the projection 1 for locking on the boot side
06 is blow molded in a circular shape similarly to the surrounding conical cylindrical portion 108. Accordingly, the inner circumferential surface of the surface for example six-sided on opposite each boot side retaining projection 106 of the head 102 of the end cover 103, as shown in FIG. 5, a large gap S ₁ in the center portion, both ends clearance S ₂ has a problem that not have a cause sufficient axial positioning function becomes smaller.

[0007] For example, the tie rod 11 is compressed.
When the boot 105 is bent, the end cover 10 is bent.
Since the depth of engagement between the boot side retaining projection 106 for 3 of the probe over Tsu locking annular projection 101 is no longer sufficient for shallow positioning the central portion, the boot-side retaining projection 106 of the end cover 103 a problem that no longer have the axial positioning function overcame blanking over tool locking annular projection 101.

Further, when a force to be Mawaso boots 105 in the circumferential direction acts, the clearance S of the boot-side retaining projection 106
Boot-side locking projections 10 only at both ends where ₂ is small
Since the 6 and the hexagonal head 102 come into contact with each other, there is a problem that the rigidity is reduced and the vehicle cannot ride on the end cover 103 to be positioned in the circumferential direction.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a resin boot which is less likely to be displaced in a circumferential direction or an axial direction when attached to a mating component having an end cover.

[0010]

To achieve Means for Solving the Problems] Such object, the present invention, one end portion of the steering system end cover is integrated with the head of the polyhedron for screwing and blanking over tool locking annular projection to, for blanking over Tsu locking of the end cover
In a steering resin boot that is fixed by sandwiching the front and rear of the annular projection, the inner peripheral surface of the boot-side locking projection opposed to each surface of the polyhedral head of the end cover is circumferentially opposed to the head of the end cover. It is formed on the surface facing the flat line straight-line.

[0011]

[Action] Thus, the gap between the boot side locking projection and the surface of the head of the end cover is the same. For this reason, when a rotational force acts on the resin boot, the boot-side locking projection and the head come into contact with each other over a wide area, and the force is dispersed to prevent the boot-side locking projection from being partially deformed. In other words, relatively Breakfast
Increase the rigidity of the articulation side locking projection. Further, Boo resin boot against the annular projection for blanking over tool engaging end cover
The engagement depth with the toe- side locking projection is deeper at the center.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The construction of the present invention will be described below in detail with reference to the embodiments shown in the drawings.

[0013] The steering resin boot is, usually, the end cover is screwed to the gear housing blanking over Tsu locking ring
At both ends, a large-diameter-side mounting portion that is fixed to the tie rod by a band by being locked to the projection and a small-diameter mounting portion that is fixed to the tie-rod coupling portion by the band are formed between the bellows portions. .

On the large-diameter mounting portion 1 side of the resin boot,
A conical cylindrical part 3 reaching the bellows part 2 is continuously formed,
A plurality of, for example, six concave portions 4 are formed in the cylindrical portion 3 at equal intervals in the circumferential direction. Recess 4 is formed between the position across the width of the probe over Tsu locking annular projection of the end cover from the mounting portion 1 to the position of the first peak of the bellows portion 2. The concave portion 4 is formed in a triangular shape with a depth such that it gradually becomes shallow toward the bellows portion 2 in the axial direction and becomes zero near the first peak of the bellows portion 2, and at least the end portion is formed in the circumferential direction. each surface that faces surface 5 of the head 102 of the polyhedron of the cover is formed on the surface and a flat row linear-shaped head 102 of the end cover. Therefore, the head 102 of the end cover
Between the inner surface 5 of each surface opposite to the recess 4, the clearance of the central portion S ₃ and both ends of the gap S ₄ and the same (S ₃ =
S ₄ ). The recess 4, as shown in FIG. 1, constitutes the boot side retaining projection 6 to sandwich the blanking over Tsu annular <br/> projection for locking of the end cover with the mounting portion 1. this
End cover between the boot-side locking projection 6 and the mounting portion 1
Of the probe over Tsu locking annular projection Mate to groove 7 is formed. In the present embodiment, the inner surface 5 of the recess 4 is an end.
A linear shape (plane) parallel to the surface of the head 102 of the cover 103
Is formed. Here, the inner surface 5 of the recess 4 is
Formed in a straight line parallel to the surface of the head 102 of the cover 103
Strictly with respect to the end cover head 102
It is not limited to having a parallel relationship in the meaning,
It is formed in a so-called almost parallel straight line with an inclination of
Is included. In this case, the boot-side locking projection 6
The gap between the end cover and the surface of the head 102 is almost the same
(S ₃ ≒ S ₄ ), so the gaps shown in FIG.
As in the case (S ₃ = S ₄ ), a rotational force is applied to the resin boot.
When used, the boot-side locking projection 6 and the head 102 cover a wide area.
And the force is dispersed and the boot-side locking projection 6 is partially
Deformation can be prevented.

As described above, the cylindrical portion 3 is partially depressed,
When the boot-side locking projection 6 is formed, molding by blow molding is possible. Here, in order to mold the inner peripheral surface 5 of the boot-side locking projections 6 on the surface and a flat row linear-shaped head 102 of the end cover, the outer mold of the boot side <br/> during blow molding The radius of the curved surface of the portion corresponding to the locking projection 6 is made larger than the radius of curvature of the circular arc connecting both ends of the portion corresponding to the boot-side locking projection 6 with the center of curvature being the same as the center of curvature of the boot . Here, will be the time that the parison when the radius of curvature is equivalent or less in contact with the outer type is earlier is equal to or across the entire surface of the boot-side locking projection 6, a gap S ₃ at the center portion increases. Further, when the portion corresponding to the boot-side locking projection 6 of the outer die is made a flat surface instead of a curved surface, the parison of the portion corresponding to the vicinity of the center of the boot-side locking projection 6 comes into contact with the outer die quickly. Refrigerated becomes elongation difficult relatively thick and, also both end portions become be extended to the cylindrical portion 3, is not suitable result clearance S ₄ in the vicinity of both ends is increased as. In addition, since it has a triangular shape that gradually becomes shallower in the axial direction, the strength of the boot-side locking projection 6 is sufficient, and the boot-side locking projection 6 is deformed when the boot is assembled, and the gear is formed. it neither to or over the blanking over tool locking annular projection of the housing is also improved strength of the cylindrical portion.

[0016] which is configured as described above, blanking over tool locking annular collision of the end cover 103 which is attached the mounting portion 1 of the large diameter side of the resin boot to the ends of the steering apparatus <br/> electromotive if it mounted beyond 101, while the clamped fixing band, the resin boot and the blanking over tool locking annular projection 101 of the end cover 103 so pinched by the mounting portion 1 and the boot-side locking projections 6 Fixed. In this state, when a rotational force acts on the resin boot, the boot-side locking projection 6 and the head 102 come into contact with each other in a wide range, and the force is dispersed to partially form the boot-side locking projection 6. Deformation can be prevented. That is, the rigidity of the boot-side locking projection is relatively increased. Further, positional deviation in the axial direction of depth of engagement is deeply in the central portion between the boot side locking protrusion 6 of the resin boot for blanking over Tsu locking annular collision <br/> force 101 of the end cover 103 Effectively prevent

The above embodiment is an example of a preferred embodiment of the present invention, but the present invention is not limited to this embodiment, and various modifications can be made without departing from the scope of the present invention. For example, in this embodiment, since the head of the end cover is hexagonal, the boot-side locking projections are provided at six locations at equal intervals in the circumferential direction. However, the present invention is not particularly limited to this. According to the number of octagons and pentagons, the number is arbitrary. Further, the end of the concave portion is extended to the bellows portion, but may be terminated in the middle of the cylindrical portion, or both may be arranged in combination.

[0018]

As is apparent from the above description, in the steering resin boot of the present invention, the inner peripheral surface of the boot-side locking projection opposed to each surface of the head of the polyhedron of the end cover extends in the circumferential direction. because it is formed on the surface and a flat line straight-line facing the head of the end cover, the gap between the surface of the head of the projections and the end cover boot side fastening is substantially the same, the resin boot even as a force which tends to rotate worked, Boo
The two-sided locking projections come into wide contact with the head of the end cover to disperse the force and increase the rigidity of the boot-side locking projections relatively to prevent the problem of riding on the end cover. Direction can be given. Further, since the depth of engagement of the projections boot side locking against the boot locking annular projection of the end cover is deeper at the central portion, even if the tie rod is inclined boot is bent in a compressed state, Boo
The toe locking projections do not cross over the boot locking annular projections of the end cover, and the axial positioning function is not impaired.

[Brief description of the drawings]

FIG. 1 is a view showing one embodiment of a resin boot of the present invention;
(A) is a longitudinal sectional view of the large-diameter side mounting portion and the boot-side locking projection, and (B) is a sectional view taken along the line II.

FIG. 2 is an enlarged sectional view of a main part showing a relationship between a boot-side locking projection and a head of an end cover.

FIG. 3 is a partial cross-sectional front view showing a mounting relationship between a steering device having an end cover and a resin boot.

FIG. 4 is a sectional view of a boot-side locking projection of a conventional resin boot.

FIG. 5 is an enlarged sectional view of a main part showing a relationship between a boot-side locking projection of the conventional resin boot shown in FIG. 4 and a head of an end cover.

[Explanation of symbols]

DESCRIPTION OF REFERENCE NUMERALS 1 Mounting portion 5 Boot-side locking projections facing each surface of end cover head 6 Boot-side locking projections facing each surface of end cover head

Claims (1)

(57) [Scope of request for utility model registration] One end portion of claim 1. A steering apparatus end cover is integrated with the head of the polyhedron for screwing and blanking over tool locking annular projection, of the probe over Tsu locking annular projection of said end cover In a steering resin boot that is fixed so as to sandwich the front and rear, the inner peripheral surface of the boot-side locking projection facing each surface of the head of the polyhedron of the end cover faces the head of the end cover in the circumferential direction. steering resin boot, characterized in that it is formed on the surface and a flat <br/> row linear shape that.