JP2016211677A - Boot and boot fitting structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a boot excellent in assemblability.SOLUTION: A boot 30 includes a first annular end part 31 fastened to an outer periphery 21a of an end part 21 of a housing 20 by an endless band 40, the endless band having a diameter reduced by caulking. The first annular end part 31 has an outer peripheral groove 34 in which the endless band 40 is stored, and an annular projection part 35 having no end or ends for band prevention which is arranged adjacently to the outer peripheral groove 34. In a part in a peripheral direction Z of the annular projection part 35, a recess 36 recessed radially inward Y2 is formed. The endless band 40 before caulking (before diameter reduction) is passed through the recess part 36, and fitted into the outer peripheral groove 34.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a boot and a boot mounting structure.

A rack and pinion type steering device is known as a steering device for automobiles and the like. This rack-and-pinion type steering device includes a pinion shaft that rotates by steering a steering wheel (handle), and a rack shaft that meshes with the pinion shaft and moves in the axial direction by the rotation of the pinion shaft.
The rack shaft is supported in a cylindrical housing so as to be movable in the axial direction. Both ends of the rack shaft protrude from the housing. In addition, tie rods are connected to both ends of the rack shaft via ball joints, respectively. The ends of the rack shaft and the ball joint are covered and protected by elastic bellows-like boots.

  In Patent Document 1, the end of the boot is fixed to the outer periphery of the end of the housing by tightening the band fitted in the band fixing groove on the outer periphery of the boot. Further, in order to prevent the band from falling off the band fixing groove, a band stopper including an annular convex portion adjacent to the band fixing groove is provided on the outer periphery of the boot.

Japanese Patent Laid-Open No. 10-267126

  An endless fastening band that can be reduced in diameter by caulking may be used as the band. In that case, first, the band before the diameter reduction is mounted on the band fixing groove over the annular convex portion (band stopper) of the boot fitted on the housing. Thereafter, the band is reduced in diameter by caulking, and the end of the boot is fastened and fixed to the outer periphery of the housing by the reduced diameter band.

If the inner diameter of the band before diameter reduction is large, the amount of diameter reduction of the band due to caulking becomes large, and caulking becomes difficult. Therefore, when the inner diameter of the band before the diameter reduction is reduced, the difference between the inner diameter of the band and the outer diameter of the annular convex portion of the boot is reduced. For this reason, it becomes difficult for the band to get over the annular convex portion, and the assemblability is lowered.
Accordingly, an object of the present invention is to provide a boot and a boot mounting structure excellent in assemblability.

  The invention of claim 1 comprises an annular end (31) that is fastened and fixed to the outer periphery (21a) of the end (21) of the housing (20) by an endless band (40) reduced in diameter by caulking, The annular end portion includes an outer peripheral groove (34) in which the endless band is accommodated, and an endless or endless annular convex portion (35) for preventing the band from being disposed adjacent to the outer peripheral groove, A boot (30) is provided in which a concave portion (36) is formed in a part of the annular convex portion in the circumferential direction (Z) and is recessed inward in the radial direction (Y2).

In addition, although the alphanumeric character in a parenthesis represents the corresponding component etc. in embodiment mentioned later, this does not mean that this invention should be limited to those embodiment as a matter of course. The same applies hereinafter.
As in claim 2, in claim 1, the bottom (36a) of the recess may be formed flush with the groove bottom (34a) of the outer peripheral groove.

According to a third aspect of the present invention, there is provided the housing, the boot according to claim 1 or 2 fitted to the outer periphery of the end portion of the housing, and the endless fit fitted into the outer peripheral groove of the boot and reduced in diameter by caulking. A boot mounting structure (A) including a band is provided.
As in claim 4, in claim 3, the groove bottom diameter (D1) of the outer peripheral groove may be equal to the inner diameter (D2) of the endless band before diameter reduction.

In the boot according to the first aspect of the present invention, the endless band can be easily fitted into the outer peripheral groove through the concave portion of the annular convex portion adjacent to the outer peripheral groove of the annular end portion of the boot. There is no need for the endless band to get over the annular convex portion, and the assemblage with the endless band is improved.
In the invention of claim 2, the bottom of the recess and the groove bottom of the outer peripheral groove are flush with each other. For this reason, it becomes easy to incorporate into the outer peripheral groove through the recess, and the assemblability with respect to the endless band is further improved.

In the invention of claim 3, it is possible to realize a boot mounting structure excellent in assemblability. Moreover, the endless band before caulking can be reduced in diameter. For this reason, the caulking allowance of the endless band can be reduced. Thereby, the tightening by the endless band can be stabilized and the sealing performance of the boot mounting structure can be improved.
In the invention of claim 4, the endless band before caulking can be further reduced in diameter. For this reason, through further reduction of the caulking allowance of the endless band, the tightening by the endless band can be further stabilized and the sealing performance of the boot mounting structure can be further improved.

1 is a schematic diagram of a schematic configuration of a steering device including a boot mounting structure to which a boot according to an embodiment of the present invention is applied. It is sectional drawing of the principal part of boot mounting structure. It is a perspective view of boots. It is the schematic of the principal part of an endless band. (A) shows the caulking scheduled part in the stage before the endless band is caulked, and (b) shows the caulking part of the endless band. (A) And (b) is the schematic sectional drawing and schematic perspective view which show the assembly process of a boot attachment structure sequentially.

Embodiments of the present invention will be specifically described below with reference to the accompanying drawings.
FIG. 1 is a schematic configuration diagram of a steering apparatus 1 including a boot mounting structure A to which a boot 30 according to an embodiment of the present invention is applied. As shown in FIG. 1, the steering device 1 includes a steering member 2 such as a steering wheel and a steering mechanism 4 that steers the steered wheels 3 in conjunction with the rotation of the steering member 2.

The steering device 1 includes a steering shaft 5 having a steering member 2 attached to one end thereof, and an intermediate shaft 6.
The steered mechanism 4 is configured by, for example, a rack and pinion mechanism. The steering mechanism 4 includes a pinion shaft 7 and a rack shaft 8. The pinion shaft 7 is connected to the steering shaft 5 via the intermediate shaft 6. The pinion shaft 7 forms a pinion 7a in the vicinity of its end. The rack shaft 8 forms a rack 8 a that meshes with the pinion 7 a of the pinion shaft 7.

The rack shaft 8 extends in the axial direction X (the left-right direction of the vehicle). The rack shaft 8 is supported in a housing 20 fixed to the vehicle body so as to be linearly reciprocable in the axial direction X via a plurality of bearings (not shown). The housing 20 is made of, for example, an aluminum alloy or an iron alloy.
Each end 81 of the rack shaft 8 protrudes from a corresponding end 21 of the housing 20. Each end portion 81 of the rack shaft 8 is connected to one end portion 10 a of the corresponding tie rod 10 via the corresponding ball joint 9. The other end portion 10 b of each tie rod 10 is connected to the corresponding steered wheel 3 via the corresponding knuckle arm 11.

The steering device 1 includes a pair of cylindrical boots 30. Each boot 30 covers the end portion 21 of the housing 20, the end portion 81 of the rack shaft 8, the ball joint 9, and a part of the tie rod 10. The boot 30 is formed of a synthetic resin such as a polyolefin-based elastomer, and can be expanded and contracted.
Each boot 30 includes a first annular end portion 31, a second annular end portion 32, and a bellows portion 33. The first annular end 31 is fastened and fixed to the outer periphery 21 a of the end 21 of the housing 20. The second annular end portion 32 is fastened and fixed to the outer periphery of the middle portion of the tie rod 10. The bellows portion 33 is interposed between the first annular end portion 31 and the second annular end portion 32, and the crest portions and the trough portions are alternately arranged.

When the steering member 2 is rotated and the steering shaft 5 is rotated, this rotation is converted into a linear motion in the axial direction X of the rack shaft 8 by the pinion 7a and the rack 8a. Thereby, the turning of the steered wheel 3 is achieved.
Further, as the rack shaft 8 moves in the axial direction X, one of the boots 30 is extended, and the other boot 30 is shortened. At this time, the bellows portion 33 of the boot 30 flexibly expands and contracts to follow the movement of the rack shaft 8.

The first annular end portion 31 of each boot 30 is attached to the outer periphery 21 a of the corresponding end portion 21 of the housing 20 using the boot attachment structure A.
As shown in FIG. 2, the boot mounting structure A fixes the housing 20, the boot 30 fitted to the outer periphery 21 a of the end portion 21 of the housing 20, and the boot 30 to the outer periphery 21 a of the end portion 21 of the housing 20. And an endless band 40 for the purpose.

The endless band 40 is made of metal, for example. As shown in FIG. 4B, the endless band 40 includes an annular main body 41 and a caulking portion 42 provided on a part of the main body 41. The endless band 40 can be reduced in diameter so as to shorten the peripheral length of the main body 41 by forming a caulking portion 42.
Specifically, as shown in FIG. 4A, the endless band 40 at the stage before caulking (before diameter reduction) is to be caulked in a groove shape having a pair of leg portions 43 in a part of the circumferential direction Z. A portion 42P is formed. As shown in FIG. 4 (b), the center portion of the pair of leg portions 43 of the planned caulking portion 42P is plastically deformed inwardly to form the caulking portion 42, whereby the endless band 40 is reduced in diameter. Is done.

As shown in FIGS. 2 and 3, the first annular end portion 31 of the boot 30 is fitted to the outer periphery of the end portion 21 of the housing 20. The first annular end portion 31 is fastened and fixed to the outer periphery 21 a of the end portion 21 of the housing 20 by an endless band 40 whose diameter is reduced by caulking.
On the outer periphery 31a of the first annular end portion 31 of the boot 30, an outer peripheral groove 34 in which the endless band 40 is accommodated, and an annular convex portion 35 disposed adjacent to the outer peripheral groove 34 and projecting radially outward Y1 Is formed. The annular convex portion 35 extends in the circumferential direction Z of the first annular end portion 31. The annular protrusion 35 functions to prevent the endless band 40 from coming off from the outer circumferential groove 34.

A part of the annular convex part 35 in the circumferential direction Z is formed with a concave part 36 that is recessed inward in the radial direction Y2. The bottom 36 a of the recess 36 is formed flush with the groove bottom 34 a of the outer circumferential groove 34. The annular convex portion 35 is terminated in the circumferential direction Z.
The formation range of the recess 36 in the circumferential direction Z may be a range corresponding to 45 °, for example, the central angle of the first annular end 31. The central angle may be a predetermined value within a range of 40 ° to 90 °.

On the outer periphery 21 a of the end portion 21 of the housing 20, an accommodation recess 22 made of an outer peripheral groove is formed. The outer peripheral groove 34 of the boot 30 is arranged on the outer side Y1 in the radial direction of the housing recess 22 on the outer periphery 21a of the end portion 21 of the housing 20.
FIG. 5 shows an assembly process of the boot mounting structure A.
First, as shown in FIG. 5A, the endless band 40 before caulking (before diameter reduction) is temporarily held over the position close to the end 21 of the housing 20, and the end 21 of the housing 20 is The first annular end 31 of the boot 30 is fitted on the outer periphery 21a.

The inner diameter D2 of the endless band 40 before the diameter reduction (the inner diameter of the main body 41) is equal to the groove bottom diameter D1 of the groove bottom 34a of the outer peripheral groove 34 of the boot 30.
Next, as shown in FIG. 5B, the endless band 40 is fitted into the outer peripheral groove 34 through the concave portion 36 of the annular convex portion 35 adjacent to the outer peripheral groove 34 of the first annular end portion 31 of the boot 30. .

Next, the endless band 40 is reduced in diameter by forming a caulking portion 42 shown in FIG. 4B in the endless band 40 fitted in the outer circumferential groove 34. As a result, as shown in FIG. 2, the first annular end portion 31 of the boot 30 is fastened and fixed to the outer periphery 21 a of the end portion 21 of the housing 20 by the endless band 40.
In the boot 30 of this embodiment, the endless band 40 can be easily fitted into the outer circumferential groove 34 through the concave portion 36 of the annular convex portion 35 adjacent to the outer circumferential groove 34 of the first annular end portion 31 of the boot 30. it can. For this reason, the operation | work which gets over the annular convex part 35 on the endless band 40 becomes unnecessary, and the assembly property of the boot 30 with respect to the endless band 40 improves.

Further, the bottom 36 a of the recess 36 and the groove bottom 34 a of the outer circumferential groove 34 are flush with each other. For this reason, it becomes easy to incorporate into the outer peripheral groove 34 through the recess 36, and the assemblability of the boot 30 with respect to the endless band 40 is further improved.
Further, in the boot mounting structure A including the housing 20, the boot 30 and the endless band 40, the assemblability can be improved. Moreover, the endless band 40 before caulking (before diameter reduction) can be reduced in diameter. For this reason, the caulking allowance of the endless band 40 can be reduced. Thereby, the tightening by the endless band 40 can be stabilized and the sealing performance of the boot mounting structure A can be improved.

Further, the groove bottom diameter D1 of the outer peripheral groove 34 of the boot 30 is made equal to the inner diameter D2 of the endless band 40 before the diameter reduction. Therefore, the endless band 40 before the diameter reduction can be further reduced in diameter. For this reason, through further reduction of the caulking allowance of the endless band 40, the tightening by the endless band 40 can be further stabilized and the sealing performance of the boot mounting structure A can be further improved.
In the present embodiment, the bottom 36a of the recess 36 is formed flush with the groove bottom 34a of the outer circumferential groove 34. However, the present invention is not limited to this, and the bottom 36a of the recess protrudes radially outward from the groove bottom 34a. May be. In that case, the annular convex portion 35 is continuous in the circumferential direction Z and is endless.

Moreover, the annular convex part 35 may be provided so that a plurality may be arranged in the circumferential direction Z.
Moreover, you may apply the boot attachment structure A of this invention to the structure which attaches the 2nd cyclic | annular end part 32 of the boot 30 to a tie rod.

  DESCRIPTION OF SYMBOLS 1 ... Steering device, 2 ... Steering member, 3 ... Steering wheel, 5 ... Steering shaft, 7 ... Pinion shaft, 8 ... Rack shaft, 9 ... Ball joint, 10 ... Tie rod, 11 ... Knuckle arm, 20 ... Housing, 21 ... End part, 21a ... outer periphery, 22 ... receiving recess, 30 ... boot, 31 ... first annular end part, 31a ... outer periphery, 32 ... second annular end part, 33 ... bellows part, 34 ... outer peripheral groove, 34a ... Bottom, 35 ... annular convex part, 36 ... concave part, 36a ... bottom, 40 ... endless band, 41 ... main body, 42 ... caulking part, 42P ... planned caulking part, A ... boot mounting structure, D1 ... (outer circumferential groove) groove Bottom diameter, D2 ... Inner diameter (of endless band before diameter reduction), X ... Axial direction, Y1 ... Radially outward, Y2 ... Radially inward, Z ... Circumferential direction

Claims (4)

An annular end portion fastened to the outer periphery of the end portion of the housing by an endless band that is reduced in diameter by caulking,
The annular end portion includes an outer circumferential groove into which the endless band is fitted, and an endless or end-like annular convex portion for preventing a band from being disposed adjacent to the outer circumferential groove,
The boot in which the recessed part dented to radial direction inward is formed in a part of circumferential direction of the said annular convex part.   The boot according to claim 1, wherein a bottom of the recess is flush with a bottom of the outer circumferential groove.   A boot mounting comprising: a housing; a boot according to claim 1 or 2 fitted to an outer periphery of an end portion of the housing; and an endless band fitted into an outer circumferential groove of the boot and reduced in diameter by caulking. Construction.   4. The boot mounting structure according to claim 3, wherein a groove bottom diameter of the outer peripheral groove is equal to an inner diameter of the endless band before being reduced.

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