JP2017001623A - Rack guide device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rack guide device which inhibits contact sounds from being caused by metal contact resulting from falling of a rack guide.SOLUTION: A rack guide device 20 includes a metal rack guide 50, which is stored in a storage part 31 formed in a housing 30 (a metal member) so as to be movable in an advance direction Y1 toward a rack shaft 8 side and a retreat direction Y2 opposite to the advance direction. The rack guide 50 supports a rack shaft 8 so that the rack shaft 8 can slide in an axial direction of the rack shaft 8. A biasing member 60 disposed between an end member 40 fixed to an exterior opening end part 32 of the storage part 31 and the rack guide 50 biases the rack guide 50 in the advance direction Y1. A resin made cylindrical member 70 is disposed between an inner peripheral surface 31a of the storage part 31 and an outer peripheral surface 53 of the rack guide 50.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a rack guide device.

  A pair of circumferential grooves that are spaced apart in the movement direction of the rack guide are provided on the outer peripheral cylindrical surface of a rack guide (also referred to as a support yoke) that guides the movement of the rack shaft in the axial direction, and a pair of housings respectively accommodated in the pair of circumferential grooves A rack guide mechanism has been proposed in which the annular elastic member comes into contact with the inner peripheral surface of a housing portion such as a housing (see, for example, Patent Documents 1 and 2).

JP 2013-177069 A JP 2013-10390 A

The pair of ring-shaped elastic members that are spaced apart in the direction of movement of the rack guide has a certain effect to suppress the rack guide from falling down (falling of the central axis of the outer peripheral cylindrical surface of the rack guide with respect to the central axis of the housing portion). Demonstrate.
However, when the rack guide is subjected to a strong tilting force, the outer peripheral cylindrical surface of the metal rack guide and the inner peripheral surface of the housing portion such as a metal housing may come into contact with each other, and contact noise due to metal contact may be generated. .

  The objective of this invention is providing the rack guide apparatus which can suppress generation | occurrence | production of the contact sound by the metal contact resulting from the fall of a rack guide.

  In the first aspect of the present invention, the advancing direction (Y1) toward the rack shaft (8) and the retreating direction (Y2) that is opposite to the advancing direction in the accommodating portion (31) defined by the metal member (30). And a metal rack guide (50) that is slidably supported and supports the rack shaft so as to be slidable in the axial direction (X) of the rack shaft, and an end portion on the retracting direction side in the housing portion. An end member (40) fixed to the external opening end (32), and a biasing member (60) interposed between the end member and the rack guide to bias the rack guide in the advance direction; Provided is a rack guide device (20) comprising a resin cylindrical member (70) interposed between an inner peripheral surface (31a) of the housing portion and an outer peripheral surface (53) of the rack guide.

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.
According to a second aspect of the present invention, the cylindrical member includes a first protrusion (71) provided on the outer peripheral surface of the rack guide, and the inner peripheral surface of the housing portion includes the first convex portion. It may include a first recess (34) that is fitted to restrict movement of the tubular member in the advance direction and the reverse direction.

As in claim 3, the tubular member includes an axial slit (74) extending in the axial direction (J) of the tubular member, and is elastically fitted to the inner peripheral surface of the housing portion. Good.
As in claim 4, the inner peripheral surface of the cylindrical member is arranged to be spaced apart from each other in the circumferential direction (C) of the cylindrical member, and is in sliding contact with the outer peripheral surface of the rack guide. The convex part (73) may be included.

According to a fifth aspect of the present invention, the sliding protrusion may include an axial rib (73) extending in the axial direction of the cylindrical member.
According to a sixth aspect of the present invention, the cylindrical member includes a second convex portion (72) provided on the outer peripheral surface, and the inner peripheral surface of the accommodating portion is fitted with the second convex portion. A second recess (35) that restricts the circumferential movement of the cylindrical member may be included.

In the first aspect of the present invention, a resin-made cylindrical member is interposed between the inner peripheral surface of the housing portion of the metal member and the outer peripheral surface of the rack guide. For this reason, it can suppress that the inner peripheral surface of the accommodating part of a housing and the outer peripheral surface of a rack guide contact, and generate | occur | produce the contact sound by a metal contact.
In the invention of claim 2, the axial movement of the cylindrical member relative to the housing is restricted by fitting the first convex portion of the outer peripheral surface of the cylindrical member into the first concave portion of the inner peripheral surface of the accommodating portion.

In the invention of claim 3, the cylindrical member having the axial slit can be elastically reduced in diameter and elastically fitted to the inner peripheral surface of the housing portion.
In the invention of claim 4, the cylindrical member is in sliding contact with the outer peripheral surface of the rack guide at a plurality of sliding protrusions spaced in the circumferential direction. For this reason, the sliding resistance of the rack guide can be reduced.
In the invention of claim 5, the occurrence of the rack guide falling can be suppressed by the axial rib as the sliding convex portion.

  According to the sixth aspect of the present invention, the second convex portion on the outer peripheral surface of the cylindrical member is fitted into the second concave portion on the inner peripheral surface of the accommodating portion, whereby the circumferential movement of the cylindrical member is restricted.

1 is a schematic diagram of a schematic configuration of a steering device to which a rack guide device according to an embodiment of the present invention is applied. It is sectional drawing of the principal part of a steering device containing a rack guide apparatus. It is III-III sectional drawing of FIG. It is a perspective view of a cylindrical member.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
FIG. 1 is a schematic diagram showing a schematic configuration of a steering device to which a rack guide device according to an embodiment of the present invention is applied. Referring to FIG. 1, the steering device 1 includes a steering member 2 such as a steering wheel that is rotated, 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 also 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 steered mechanism 4 includes a pinion shaft 7 and a rack shaft 8 as a steered shaft. 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 on the outer periphery of a part of the axial direction X.

  The rack shaft 8 is supported in a rack housing 9 fixed to the vehicle body so as to be movable in the axial direction X (corresponding to the left-right direction of the vehicle body) via a rack bush B or the like. Each end of the rack shaft 8 protrudes from the corresponding end of the rack housing 9 to both sides. Each end of the rack shaft 8 is connected to a corresponding steered wheel 3 via a corresponding tie rod 10 and a corresponding knuckle arm (not shown).

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.
The steering device 1 includes a rack guide device 20. The rack guide device 20 is disposed on the opposite side of the pinion 7 a with respect to the rack shaft 8. The rack guide device 20 functions to guide the movement of the rack shaft 8 in the axial direction X while urging the rack shaft 8 toward the pinion 7a.

FIG. 2 is a cross-sectional view of a main part of the steering device 1. As shown in FIG. 2, the steering device 1 includes a pinion housing 11, a first bearing 12, and a second bearing 13. The pinion housing 11 is integrally attached to the rack housing 9.
The first bearing 12 and the second bearing 13 are held by the pinion housing 11 and rotatably support the pinion shaft 7 within the pinion housing 11. The first bearing 12 and the second bearing 13 are disposed on both sides of the pinion 7 a with respect to the axial direction of the pinion shaft 7. The first bearing 12 supports one end 7 b in the axial direction of the pinion shaft 7, and the second bearing 13 supports the other end 7 c in the axial direction of the pinion shaft 7.

The 1st bearing 12 consists of a ball bearing, for example. The 2nd bearing 13 consists of cylindrical roller bearings, for example. The pinion 7 a of the pinion shaft 7 and the rack 8 a of the rack shaft 8 are meshed with each other in the pinion housing 11.
The rack guide device 20 includes a housing 30 as a metal member, an end member 40, a metal rack guide 50, an urging member 60, and a resin tubular member 70.

The housing 30 is provided integrally with the pinion housing 11. The housing 30 is disposed on the opposite side to the pinion 7a with the rack shaft 8 therebetween.
A housing 31 is formed in the housing 30. That is, the accommodating part 31 is divided by the metal member (housing 30). The rack shaft 8 is inserted into the accommodating portion 31 in an intersecting manner. The accommodating portion 31 includes an inner peripheral surface 31a that is a cylindrical inner peripheral side surface. An external opening end portion 32 is formed in the accommodating portion 31 as an end portion on the side opposite to the rack shaft 8 side (a retreat direction Y2 side described later). The end member 40 is formed by a metal plug (plug) that is fixed by screw fitting to the inner periphery of the outer opening end portion 32.

The end member 40 includes a first surface 41, a second surface 42, and an outer peripheral surface 43. The first surface 41 faces the rack guide 50. The second surface 42 is provided on the opposite side of the first surface 41. A male screw 44 and an outer peripheral groove 45 are formed on the outer peripheral surface 43 of the end member 40. The outer peripheral groove 45 of the end member 40 is disposed closer to the rack guide 50 than the male screw 44.
An internal thread 33 is formed in a range of a predetermined length from the external opening end 32 of the housing part 31. The male screw 44 of the end member 40 is screwed into the female screw 33, and the end member 40 is fixed to the housing 30. The end member 40 closes and seals the external opening end portion 32.

A tool engagement hole 46 is formed in the second surface 42 of the end member 40. The tool engagement hole 46 is formed in, for example, a polygonal cross section so that a tool for screwing the end member 40 from the external opening end portion 32 side is engaged.
A seal member 47 is accommodated in the outer peripheral groove 45 of the end member 40. The seal member 47 is made of an annular elastic member such as an O-ring. The seal member 47 fulfills the function of sealing between the outer peripheral surface 43 of the end member 40 and the inner peripheral surface 31a of the accommodating portion 31.

The rack guide 50 is accommodated in the accommodating portion 31 so as to be able to advance and retract in an advancing direction Y1 toward the rack shaft 8 and a retreating direction Y2 that is opposite to the advancing direction Y1. Hereinafter, the advancing direction Y1 and the backward direction Y2 are collectively referred to as the forward / backward direction Y.
The rack guide 50 includes a first surface 51, a second surface 52, and an outer peripheral surface 53 that is a cylindrical outer peripheral surface. The first surface 51 faces the rack shaft 8. The second surface 52 is provided on the opposite side of the first surface 51. The rack guide 50 is made of metal.

  The rack guide 50 slidably supports the back surface 8b of the rack 8a of the rack shaft 8. Specifically, the first surface 51 of the rack guide 50 is formed with a concave surface 54 having a shape that substantially matches the shape of the back surface 8 b of the rack shaft 8. A slidable contact plate 55 that is curved along the concave surface 54 is fixed to the concave surface 54. The sliding contact plate 55 is in sliding contact with the back surface 8 b of the rack shaft 8. As the sliding contact plate 55, a plate having a low friction coefficient is preferably used. For example, a metal plate or a metal plate coated with a fluororesin can be used.

The second surface 52 of the rack guide 50 is formed with a recess 56 formed of a circular hole concentric with the cylindrical surface formed by the outer peripheral surface 53.
The biasing member 60 is made of a compression coil spring, for example. The urging member 60 is interposed between the bottom of the concave portion 56 of the second surface 52 of the rack guide 50 and the first surface 41 of the end member 40 in an elastically compressed state. The urging member 60 urges the rack guide 50 toward the rack shaft 8 (the advance direction Y1).

3 is a cross-sectional view taken along the line III-III in FIG. FIG. 4 is a perspective view of the cylindrical member 70. Below, the structure of the cylindrical member 70 made from resin is demonstrated, referring FIGS.
The cylindrical member 70 is interposed between the inner peripheral surface 31 a of the accommodating portion 31 and the outer peripheral surface 53 of the rack guide 50. The cylindrical member 70 includes a cylindrical outer peripheral surface 70a and a cylindrical inner peripheral surface 70b concentric with the outer peripheral surface 70a. The outer peripheral surface 70 a of the cylindrical member 70 is elastically fitted to the inner peripheral surface 31 a of the housing portion 31 with a slight fastening margin.

The cylindrical member 70 includes a first convex portion 71 and a second convex portion 72 provided on the outer peripheral surface 70a. The cylindrical member 70 includes axial ribs 73 as a plurality of sliding protrusions provided on the inner peripheral surface 70b.
On the inner peripheral surface 31 a of the housing portion 31, there is a first recess 34 that fits with the first protrusion 71 of the tubular member 70 and restricts the axial movement (movement in the forward / backward direction Y) of the tubular member 70. Is formed. As shown in FIG. 4, the first convex portion 71 is formed by an outward annular flange that extends around the entire circumference of the outer peripheral surface 70 a of the cylindrical member 70. The first recess 34 is formed by an inner circumferential groove extending along the entire circumference of the inner circumferential surface 31 a of the housing portion 31.

A second concave portion 35 that is fitted to the second convex portion 72 of the cylindrical member 70 and partly moves in the circumferential direction C of the cylindrical member 70 at a part of the inner peripheral surface 31 a of the accommodating portion 31. Is formed. The 1st convex part 71 and the 2nd convex part 72 are spaced apart and arrange | positioned at the axial direction J (coincidence with the advancing / retreating direction Y) of the cylindrical member 70. As shown in FIG.
The plurality of axial ribs 73 extend in the axial direction J of the tubular member 70 and are spaced apart in the circumferential direction C of the tubular member 70. The axial rib 73 of the cylindrical member 70 may be in contact with the outer peripheral surface 53 of the rack guide 50 with zero tightening (that is, zero touch). Further, the axial rib 73 may be loosely fitted to the outer peripheral surface 53 of the rack guide 50. Further, the axial rib 73 may be elastically fitted to the outer peripheral surface 53 of the rack guide 50 by providing a slight fastening allowance.

When the rack guide 50 moves in the forward / backward direction Y, the axial rib 73 of the cylindrical member 70 comes into sliding contact with the outer peripheral surface 53 of the rack guide 50.
The tubular member 70 forms an axial slit 74 that extends in the axial direction J of the tubular member 70. By reducing the slit width of the axial slit 74, the cylindrical member 70 can be elastically reduced in diameter.

At the time of assembly, the cylindrical member 70 is once reduced in diameter, and after the cylindrical member 70 is accommodated in the accommodating portion 31, the cylindrical member 70 is expanded in diameter, so that the first convex portion 71 becomes the first concave portion 34. The second convex portion 72 is fitted into the second concave portion 35. Thereby, the movement of the cylindrical member 70 in the axial direction J and the movement in the circumferential direction C are restricted.
In the present embodiment, a resin-made cylindrical member 70 is interposed between the inner peripheral surface 31 a of the housing portion 31 of the housing 30 (metal member) and the outer peripheral surface 53 of the metal rack guide 50. For this reason, it can suppress that the inner peripheral surface 31a of the accommodating part 31 of the housing 30 and the outer peripheral surface 53 of the rack guide 50 contact, and generate | occur | produce the contact sound by a metal contact.

Further, the first convex portion 71 of the outer peripheral surface 70 a of the cylindrical member 70 is fitted into the first concave portion 34 of the inner peripheral surface 31 a of the accommodating portion 31, so that the cylindrical member 70 moves in the axial direction J with respect to the housing 30. Is regulated.
Further, since the axial slit 74 is provided in the cylindrical member 70, the cylindrical member 70 can be elastically reduced in diameter and can be elastically fitted to the inner peripheral surface 31 a of the housing portion 31.

Further, the cylindrical member 70 is in sliding contact with the outer peripheral surface 53 of the rack guide 50 at a plurality of sliding protrusions (axial ribs 73) that are separated in the circumferential direction C. For this reason, compared with the case where the cylindrical member 70 contacts the outer peripheral surface 53 of the rack guide 50 in the perimeter, the sliding resistance of the rack guide 50 can be reduced.
Moreover, since the sliding convex part is comprised by the some axial rib 73, generation | occurrence | production of the fall of the rack guide 50 can be suppressed by these axial ribs 73. FIG.

Further, the second convex portion 72 of the outer peripheral surface 70 a of the cylindrical member 70 is fitted into the second concave portion 35 of the inner peripheral surface 31 a of the accommodating portion 31, thereby restricting the movement of the cylindrical member 70 in the circumferential direction C. Is done.
The present invention is not limited to the above-described embodiment. For example, the outer peripheral surface 70a of the cylindrical member 70 is in contact with the inner peripheral surface 31a of the accommodating portion 31 with zero tightening (that is, zero touch). Also good. Further, the outer peripheral surface 70 a of the cylindrical member 70 may be fitted loosely to the inner peripheral surface 31 a of the housing portion 31.

Although not shown, the first convex portion 71 may be formed in a part of the cylindrical member 70 in the circumferential direction C. In that case, the 1st convex part 71 and the 2nd convex part 72 may be combined.
Further, instead of each axial rib 73, a plurality of sliding protrusions spaced apart in the axial direction J of the tubular member 70 may be provided.
Although not shown, the first convex portion 71 and the second convex portion 72 are provided on the inner peripheral surface 70 b of the cylindrical member 70 so that the cylindrical member 70 moves integrally with the rack guide 50. May be. In that case, the axial rib 73 provided on the outer peripheral surface 70 a of the tubular member 70 is in sliding contact with the inner peripheral surface 31 a of the housing portion 31 of the housing 30.

  Although not shown, the end member 40 as a metal member forms a cylindrical shape to define the accommodating portion, and the space between the inner peripheral surface of the accommodating portion of the end member 40 and the outer peripheral surface 53 of the rack guide 50 is not shown. A cylindrical member 70 made of resin may be interposed therebetween. In addition, the present invention can be variously modified within the scope of the claims.

  DESCRIPTION OF SYMBOLS 1 ... Steering device, 2 ... Steering member, 3 ... Steering wheel, 4 ... Steering mechanism, 5 ... Steering shaft, 6 ... Intermediate shaft, 7 ... Pinion shaft, 7a ... Pinion, 8 ... Rack shaft, 8a ... Rack, 11 DESCRIPTION OF SYMBOLS ... Pinion housing, 20 ... Rack guide apparatus, 30 ... Housing (metal member), 31 ... Housing part, 31a ... Inner peripheral surface, 32 ... External opening end, 34 ... First recessed part, 35 ... Second recessed part, 40 ... End 41, first surface, 42, second surface, 43, outer peripheral surface, 50, rack guide, 51, first surface, 52, second surface, 53, outer peripheral surface, 60, biasing member, 70, cylinder 70a ... outer peripheral surface, 70b ... inner peripheral surface, 71 ... first convex portion, 72 ... second convex portion, 73 ... axial rib (sliding convex portion), 74 ... axial slit, C ... (cylinder) Circumferential direction (J-shaped member), J ... axial direction of cylindrical member, X ... axial direction of rack shaft, Y Forward and backward direction, Y1 ... advancing direction, Y2 ... the backward direction

Claims (6)

It is accommodated in the housing section defined by the metal member so as to be movable in the advancing direction toward the rack shaft side and in the retracting direction opposite to the advancing direction, and the rack shaft is slidably supported in the axial direction of the rack shaft. A metal rack guide to
An end member fixed to an end portion of the opening that is the end portion on the retreat direction side in the housing portion, and a biasing member that is interposed between the end member and the rack guide and biases the rack guide in the advance direction. A force member;
A rack guide device comprising: a resin tubular member interposed between an inner peripheral surface of the housing portion and an outer peripheral surface of the rack guide. In Claim 1, the said cylindrical member contains the 1st convex part provided in the said outer peripheral surface of the said rack guide,
The rack guide device including a first concave portion, wherein the inner peripheral surface of the housing portion is fitted with the first convex portion and restricts movement of the tubular member in the advance direction and the reverse direction.   The rack guide device according to claim 1, wherein the cylindrical member includes an axial slit extending in an axial direction of the cylindrical member, and is elastically fitted to the inner peripheral surface of the housing portion.   The inner circumferential surface of the cylindrical member according to any one of claims 1 to 3, wherein the inner circumferential surface of the cylindrical member is spaced apart in the circumferential direction of the cylindrical member and is in sliding contact with the outer circumferential surface of the rack guide. A rack guide device including a sliding projection.   The rack guide device according to claim 4, wherein the sliding protrusion includes an axial rib extending in an axial direction of the cylindrical member. In any one of Claims 1-5, the said cylindrical member contains the 2nd convex part provided in the said outer peripheral surface,
The rack guide device including a second concave portion, wherein the inner peripheral surface of the housing portion is fitted with the second convex portion to restrict movement of the cylindrical member in the circumferential direction.

Images