CN106394648B

CN106394648B - Steering device and gear component

Info

Publication number: CN106394648B
Application number: CN201610605658.4A
Authority: CN
Inventors: 作田雅芳; 长谷笃宗; 明法寺祐
Original assignee: JTEKT Corp
Current assignee: JTEKT Corp
Priority date: 2015-07-29
Filing date: 2016-07-28
Publication date: 2020-06-19
Anticipated expiration: 2036-07-28
Also published as: CN106394648A; JP6902213B2; ES2701925T3; JP2020109002A; JP2017030726A; JP6768192B2; DK3124354T3; DE202016008693U1

Abstract

The invention relates to a steering device and a tooth member. In the steering device, the pair of first tooth rows that are movable integrally with the upper jacket are formed by a plurality of first teeth that have a tooth direction extending in the vertical direction and are arranged at a pitch in the axial direction. The tooth member formed by press forming includes a pair of second teeth provided to extend in parallel to each other on a pair of side surfaces in the main body portion supported by the lower sheath. The pair of second teeth are engaged with the first teeth row in accordance with an operation of an operation member for restricting expansion and contraction of the column jacket. The pair of second tooth tips are offset from each other by a distance smaller than a predetermined pitch.

Description

Steering device and gear component

Technical Field

This application claims priority to Japanese patent application 2015-149823, filed on 29.7.2015, and to Japanese patent application 2016-089424, filed on 27.4.2016, and is hereby incorporated by reference in its entirety, including the specification, drawings, and abstract of the specification.

The present invention relates to a steering device and a gear member used for the steering device.

Background

In the steering column device described in japanese patent application laid-open No. 2007-238012, a steering shaft connecting a steering wheel and a steering mechanism is inserted into a column main body. A plate-shaped gear base for expansion and contraction having a plurality of teeth formed on both surfaces thereof is fixed to a side portion of the column main body. The column body is provided with a long hole in the telescopic direction through which a shaft to which the operating lever is attached is inserted. A gear member for extension and retraction is fixed to the operating lever so as to correspond to the gear base for extension and retraction. The gear member for telescopic mechanism has a plurality of teeth on a surface facing the plurality of teeth of the gear base for telescopic mechanism at the same pitch as the plurality of teeth of the gear base for telescopic mechanism. When the operation lever is rotated, the gear member for telescoping engages with the gear base for telescoping. This regulates adjustment of the telescopic (telescopic) position of the column main body.

In the steering device described in japanese patent application laid-open No. 2007-238012, in order to restrict expansion and contraction of a column jacket such as a column body after adjustment of an expansion and contraction position, teeth of a tooth member having teeth formed on both surfaces of a gear base for expansion and contraction and the like are engaged with teeth of a gear member for expansion and contraction. For the tooth member, a portion where the top portion of the tooth is formed is different in thickness from a portion where the bottom portion of the tooth is formed. Therefore, in the case of forming the tooth member by press forming, for example, the compression rate, that is, the density in press forming is different between the portion where the top portion of the tooth is formed and the portion where the bottom portion of the tooth is formed. Therefore, mechanical properties such as the strength of the gear member in the direction in which the teeth are arranged are unstable, and the strength of the engagement between the gear member and the gear base for expansion and contraction may be unstable.

Disclosure of Invention

An object of the present invention is to provide a steering device capable of stabilizing the engagement strength between teeth in a structure in which the expansion and contraction of a column jacket are restricted by the engagement between the teeth. The invention aims to provide a tooth member which can realize the stabilization of the strength.

A steering device according to an aspect of the present invention is a steering device including: a steering shaft, one end of which is connected with a steering control component and can extend and retract along the axial direction; a column jacket that has an upper jacket that holds the steering shaft on the steering member side in the axial direction and a lower jacket that holds the steering shaft on a side opposite to the steering member side in the axial direction, and that is capable of extending and contracting in the axial direction together with the steering shaft by movement of the upper jacket relative to the lower jacket in the axial direction; a bracket which supports the lower jacket and is fixed to a vehicle body; an operation member that is operated to restrict expansion and contraction of the column jacket; a pair of first tooth rows each including a plurality of first teeth extending in parallel and being movable integrally with the upper sheath in the axial direction, the plurality of first teeth having a tooth direction extending in a direction intersecting the axial direction and being arranged at a predetermined pitch in the axial direction; and a tooth member including a block-shaped main body portion supported by the under jacket, and a pair of second teeth provided on at least one of a pair of side surfaces extending in parallel to each other on the main body portion, the tooth member being movable in accordance with an operation of the operating member to mesh the pair of second teeth with the pair of first tooth rows, respectively, the pair of second teeth being formed such that tooth tips thereof are shifted from each other by a distance smaller than the predetermined pitch.

Drawings

The above and still further features and advantages of the present invention will become more apparent from the following detailed description of embodiments thereof with reference to the accompanying drawings, in which like elements are given like reference numerals, and in which,

fig. 1 is a side view showing a schematic configuration of a steering device according to an embodiment of the present invention.

Fig. 2 is a perspective view of the steering device.

Fig. 3 is a sectional view taken along the line III-III of fig. 1.

Fig. 4 is an exploded perspective view of the periphery of the tooth lock mechanism.

Fig. 5 is a view of the tooth member as viewed from the lower side.

Fig. 6 is a side view of a pattern of the tooth lock mechanism and is a diagram showing a state in which the second tooth is engaged with the first tooth.

Fig. 7 is a sectional view taken along line VII-VII of fig. 6.

Fig. 8 is a schematic side view of the tooth lock mechanism and shows a state where the engagement between the second tooth and the first tooth is released.

Fig. 9 is a view of a tooth member according to a modification of the present embodiment as viewed from below.

Fig. 10 is a rear view of a tooth member according to a modification of the present embodiment.

Detailed Description

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Fig. 1 is a side view showing a schematic configuration of a steering device 1 according to an embodiment of the present invention. In fig. 1, the left side of the drawing is the front side of the vehicle body 2 to which the steering device 1 is attached, the right side of the drawing is the rear side of the vehicle body 2, the upper side of the drawing is the upper side of the vehicle body 2, and the lower side of the drawing is the lower side of the vehicle body 2.

Referring to fig. 1, a steering device 1 mainly includes: steering shaft 3, column jacket 4, lower bracket 5, upper bracket 6, fastening mechanism 7, and tooth locking mechanism 8. A steering member 11 such as a steering wheel is coupled to the steering shaft 3 at one end 3A as the rear end thereof. The other end 3B of the steering shaft 3, which is the tip end thereof, is connected to a pinion shaft 16 of a steering mechanism 15 via a universal joint 12, an intermediate shaft 13, and a universal joint 14 in this order.

The steering mechanism 15 is constituted by a rack and pinion mechanism or the like. The steering mechanism 15 steers steered wheels (not shown) such as tires in accordance with the rotation transmission of the steering shaft 3. The steering shaft 3 extends in the front-rear direction of the vehicle body 2. Hereinafter, the direction in which the steering shaft 3 extends is referred to as the axial direction X of the steering shaft 3. The axial direction X is inclined with respect to the horizontal direction such that the other end 3B is lower than the one end 3A. A rear side in which the axial direction X is the one end 3A side is denoted by reference numeral X1, and a front side in which the axial direction X is the opposite side to the one end 3A is denoted by reference numeral X2.

A direction perpendicular to the paper surface in fig. 1 among directions intersecting the axial direction X is a left-right direction Y, and a direction extending substantially vertically in fig. 1 is a vertical direction Z. In the left-right direction Y, the depth side of the drawing sheet in fig. 1 is a right side Y1, and the front side of the drawing sheet is a left side Y2. In the vertical direction Z, the upper side is denoted by reference numeral Z1, and the lower side is denoted by reference numeral Z2. In each of the drawings other than fig. 1, the same reference numerals as those in fig. 1 are given to directions corresponding to the axial direction X, the rear side X1, the front side X2, the left-right direction Y, the right side Y1, the left side Y2, the vertical direction Z, the upper side Z1, and the lower side Z2 in fig. 1.

The steering shaft 3 includes an upper shaft 20 and a lower shaft 21 extending in the axial direction X. Upper shaft 20 is located at a rear side X1 relative to lower shaft 21. The rear end portion 21A of the lower shaft 21 is inserted from the front side X2 into the front end portion 20A of the upper shaft 20, which is formed in a cylindrical shape. The lower shaft 21 is coupled to the upper shaft 20 by spline fitting or serration fitting. Therefore, the upper shaft 20 and the lower shaft 21 are rotatable integrally and relatively movable in the axial direction X. The steering shaft 3 can be extended and retracted in the axial direction X by the movement of the upper shaft 20 relative to the lower shaft 21 in the axial direction X.

The column jacket 4 houses the steering shaft 3. The column jacket 4 has an upper jacket 22 and a lower jacket 23 extending in the axial direction X. The upper sheath 22 is located at the rear side X1 relative to the lower sheath 23. The front end portion 22A of the upper sheath 22 is fitted into the lower sheath 23 from the rear side X1.

The column jacket 4 supports and holds the steering shaft 3 rotatably via a bearing 24 and a bearing 25. Specifically, the upper sheath 22 rotatably supports the upper shaft 20 via the bearing 24, and holds the upper shaft 20 on the rear side X1. The lower sheath 23 rotatably supports the lower shaft 21 via the bearing 25, and holds the lower shaft 21 on the front side X2.

The upper shaft 20 and the upper sheath 22 coupled to each other are movable in the axial direction X relative to the lower shaft 21 and the lower sheath 23. Thereby, the column jacket 4 can be extended and contracted together with the steering shaft 3. The expansion and contraction of the steering shaft 3 and the column jacket 4 is referred to as Telescopic expansion and contraction (Telescopic). The position adjustment in the axial direction X of the steering member 11 coupled to the one end 3A of the steering shaft 3 by expansion and contraction is referred to as expansion and contraction adjustment.

The lower bracket 5 includes: a pair of left and right movable brackets 5A (see also fig. 2 described later), a fixed bracket 5B, and a center shaft 5C. A pair of left and right movable brackets 5A are fixed to the upper outer peripheral surface of the front end portion 23B of the under-jacket 23. The fixing bracket 5B is fixed to the vehicle body 2. The center axis 5C extends in the left-right direction Y. The center shaft 5C is bridged between the pair of movable brackets 5A and penetrates the fixed bracket 5B. Thereby, the front end portion 23B of the under-jacket 23 is coupled to the vehicle body 2.

The movable bracket 5A is supported by the fixed bracket 5B so as to be rotatable about the central axis 5C. Therefore, the entire column jacket 4 can be vertically rotated about the central axis 5C with respect to the fixed bracket 5B and the upper bracket 6 along with the steering shaft 3. The rotation of the column jacket 4 about the central axis 5C as a fulcrum in this manner is referred to as tilting. The substantially vertical direction along the arc centered on the central axis 5C is referred to as an oblique direction.

The position adjustment in the tilt direction of the steering member 11 based on the tilt is referred to as tilt adjustment. The column jacket 4 can be rotated in the tilt direction to adjust the tilt. The lower jacket 23 is coupled to the vehicle body 2 via the lower bracket 5, and thus cannot move in the axial direction X. Therefore, the upper sheath 22 actually moves when performing the telescopic adjustment.

The upper bracket 6 is a bracket that supports the rear end portion 23A of the lower jacket 23 and connects the rear end portion 23A to the vehicle body 2. Referring to fig. 2, which is a perspective view of the steering apparatus 1, the upper bracket 6 integrally includes a pair of side plates 30 and a connecting plate 31 that is thin in the vertical direction Z. The pair of side plates 30 are disposed to face each other in the left-right direction Y while lightly sandwiching the rear end portion 23A of the under-jacket 23 in the left-right direction Y. The coupling plate 31 is coupled to the upper end portions of the pair of side plates 30.

Inclined grooves 32 are formed in the pair of side plates 30 at the same positions when viewed in the left-right direction Y (see also fig. 3 described later). The inclined groove 32 extends in an arc shape along the inclined direction. The connecting plate 31 has portions extending outward in the left-right direction Y from the pair of side plates 30. The upper bracket 6 is integrally fixed to the vehicle body 2 by a bolt or the like (not shown) inserted through the portion (see fig. 1).

A slit 33 extending over the entire axial direction X and penetrating the lower sheath 23 in the vertical direction Z is formed in the upper outer peripheral surface of the lower sheath 23. A pair of extending portions 34 that divide the slit 33 in the left-right direction Y and extend along the upper side Z1 are integrally provided at the rear end portion 23A of the under-sheath 23. Each extending portion 34 is a plate-like shape that expands in the axial direction X and the vertical direction Z, and is thin in the lateral direction Y. The pair of extensions 34 are disposed between the pair of side plates 30, respectively, and have facing surfaces 34A facing each other in the left-right direction Y. Each extension 34 faces the side plate 30 located on the same side in the left-right direction Y from the left-right direction Y.

Fig. 3 is a sectional view taken along the line III-III of fig. 1. Referring to fig. 3, circular insertion holes 35 penetrating the extension portions 34 in the left-right direction Y are formed in the pair of extension portions 34 at the same positions as seen in the left-right direction Y. The insertion holes 35 of the pair of extensions 34 overlap with a part of the inclined grooves 32 of the pair of side plates 30 of the upper bracket 6 when viewed in the left-right direction Y.

A guide groove 37 extending in the axial direction X is formed in a portion of the lower side Z2 of the lower sheath 23. A guided projection 38 fixed to the upper jacket 22 is inserted into the guide groove 37. The guide groove 37 guides the movement of the upper sheath 22 in the axial direction X via the guided projection 38, and restricts the rotation of the upper sheath 22 relative to the lower sheath 23. The axial X end (not shown) of the guide groove 37 abuts against the guided projection 38, thereby preventing the upper sheath 22 from falling off from the lower sheath 23.

The fastening mechanism 7 is a mechanism for releasing the lock of the position of the steering member 11 (see fig. 1) or locking the position of the steering member 11 after the tilt adjustment or the telescopic adjustment for performing the tilt adjustment and the telescopic adjustment. The fastening mechanism 7 includes: the tilt bolt 40, the operation member 41, the annular cam 42 and the cam follower 43, the nut 44, the annular interposed member 45, the needle bearing 46, and the thrust washer 47.

The tilt bolt 40 is a metal bolt having a central axis 40A extending in the left-right direction Y. The tilt bolt 40 has a head 40B at a left end and a thread groove 40C at a right end of an outer peripheral surface. The portion of the tilt bolt 40 on the right side Y1 with respect to the head 40B is inserted through the tilt grooves 32 of the pair of side plates 30 and the insertion holes 35 of the pair of extensions 34 at a position above the steering shaft 3 by the distance Z1. In this state, the head 40B is positioned on the left side Y2 with respect to the side plate 30 on the left side Y2, and the screw groove 40C is positioned on the right side Y1 with respect to the side plate 30 on the right side Y1.

The operation member 41 is, for example, a rod that can be gripped. The operation member 41 includes a base end portion 41A as one end in the longitudinal direction and a grip portion 41B as the other end in the longitudinal direction. The proximal end portion 41A of the operating member 41 is attached to the vicinity of the head portion 40B of the tilt bolt 40. The driver grips the grip portion 41B of the operation member 41 and operates it. Thereby, the tilt bolt 40 is rotated together with the operation member 41 in accordance with the operation of the operation member 41.

The left end of the tilt bolt 40 is inserted through the cam 42 and the cam follower 43. The cam 42 and the cam follower 43 are juxtaposed between the head portion 40B and the side plate 30 of the left side Y2 in this order from the left side Y2. The cam 42 is rotatable integrally with the tilt bolt 40, and the cam follower 43 is rotatable relative to the tilt bolt 40 and movable in the left-right direction Y. However, since the inclined groove 32 of the side plate 30 inserted through the left side Y2 of the cam follower 43 has a width opposite to the side, the idling of the cam follower 43 can be prevented by the inclined groove 32.

A nut 44 is attached to the thread groove 40C of the tilt bolt 40. The interposed member 45, the needle roller bearing 46, and the thrust washer 47 are arranged between the nut 44 and the side plate 30 of the right side Y1 in this order from the left side Y2. The tilt bolt 40 is inserted through the interposed member 45, the needle bearing 46, and the thrust washer 47. The tilt bolt 40 is movable in the tilt direction in each tilt groove 32 of the upper bracket 6. When the driver moves the steering member 11 (see fig. 1) in the tilting direction to adjust the tilt, the entire column jacket 4 tilts relative to the upper bracket 6. The tilt adjustment of the steering member 11 is performed within a range in which the tilt bolt 40 can move in the tilt groove 32.

When the driver operates and rotates the operation member 41 after performing the telescopic adjustment or the tilt adjustment, the cam 42 rotates, and the cam protrusion 56 of the cam 42 and the cam follower 43 comes into contact with each other. Thereby, the cam follower 43 moves to the right side Y1 along the tilt bolt 40 extending in the left-right direction Y, and the cam follower 43 presses the left side surface of the side plate 30 of the left side Y2 from the left side Y2. Thereby, the distance between the cam follower 43 and the interposed member 45 in the left-right direction Y is narrowed. The pair of side plates 30 are fastened between the cam followers 43 and the interposed member 45 from both sides in the left-right direction Y. In this state, friction is maintained between each side plate 30 and the extension portion 34, and between the lower sheath 23 and the upper sheath 22, which have been reduced in diameter as they are fastened. This restricts the rotation and expansion and contraction of the column jacket 4, and the steering member 11 (see fig. 1) cannot move in the tilt direction and the axial direction X.

In this way, the state of the steering device 1 when the position of the steering member 11 is locked in the tilt direction and the axial direction X is referred to as a locked state. In normal operation, the steering device 1 is in a locked state. In the steering device 1 in the locked state, when the operation member 41 is operated and rotated in the direction opposite to the previous direction, the cam 42 rotates relative to the cam follower 43, and therefore the cam protrusions 56 of the cam 42 and the cam follower 43 are released from upward contact with each other. Thereby, the cam follower 43 moves from the locking position to the left side Y2 along the tilt bolt 40. The intermediate member 45 moves along the tilt bolt 40 toward the right side Y1 in conjunction with the movement of the cam follower 43. Thereby, the distance between the cam follower 43 and the intermediate member 45 is increased, and the fastening of the pair of side plates 30 between the cam follower 43 and the intermediate member 45 is released. In this state, the frictional retention between each side plate 30 and the extension portion 34 and between the lower sheath 23 and the upper sheath 22 is released. This enables the column jacket 4 to be rotated and expanded and contracted, and the steering member 11 to be moved in the tilt direction and the axial direction X. Therefore, the telescopic adjustment and the tilt adjustment can be performed again.

In this way, the state of the steering apparatus 1 when the positional fixation of the steering member 11 in the tilt direction and the axial direction X is released is referred to as a released state. The structure of the tooth lock mechanism 8 will be described in detail below. Referring to an exploded perspective view of the periphery of the tooth lock mechanism 8, i.e., fig. 4, the tooth lock mechanism 8 includes a tooth plate 61 and a tooth member 63. The toothed plate 61 has first teeth 60. The tooth member 63 has a second tooth 62 as a tooth portion capable of meshing with the first tooth 60. The tooth lock mechanism 8 includes a support mechanism 64, a guide mechanism 65, and an interlocking mechanism 66. The support mechanism 64 supports the tooth member 63. The guide mechanism 65 guides a part of the tooth member 63 in the vertical direction Z. The interlocking mechanism 66 interlocks the movement of the tooth member 63 with the rotation of the tilt bolt 40.

The tooth plate 61 includes a flat plate-like main body portion 70 that is long in the axial direction X, and a pair of first tooth rows 60L formed of a plurality of first teeth 60. The main body 70 is formed with a through hole 70A penetrating the main body 70 in the vertical direction Z. The through hole 70A is rectangular in shape with a long side in the axial direction X when viewed in the vertical direction Z. The first tooth rows 60L are provided in a row on each of both edges 70B of the through hole 70A in the left-right direction Y. The pair of first tooth rows 60L extend parallel to the axial direction X with an interval therebetween in the left-right direction Y.

Each first tooth 60 of each first tooth row 60L is a tooth having a so-called transverse tooth shape having a tooth top 73 with a tooth direction 74 extending in the vertical direction Z. The first teeth 60 of the first tooth row 60L of the right side Y1 protrude from the edge 70B of the right side Y1 into the through hole 70A such that the tooth tip 73A thereof faces the left side Y2. The first tooth row 60L of the left side Y2 protrudes from the edge 70B of the left side Y2 into the through hole 70A with its tooth tip 73B facing the right side Y1.

In each first tooth row 60L, a plurality of first teeth 60 are arranged at a predetermined pitch P in the axial direction X. In the axial direction X, the tooth tip 73A of the first tooth 60 of the first tooth row 60L on the right side Y1 and the tooth tip 73B of the first tooth 60 of the first tooth row 60L on the left side Y2 are shifted by a distance L corresponding to half the pitch P in the present embodiment. The distance L may be different from the present embodiment, and is not necessarily half the pitch P, and may be a distance smaller than the pitch P.

The tooth plate 61 is disposed between the pair of extensions 34 as viewed in the axial direction X (see fig. 3), and is fixed to the outer peripheral surface of the upper sheath 22 by welding or the like. Therefore, the toothed plate 61 is movable integrally with the upper sheath 22 in the axial direction X. The toothed plate 61 may be fixed to the outer peripheral surface 22B of the upper jacket 22 by bolts or the like, not shown. The toothed plate 61 may also be integrally formed from the same material as the upper sheath 22.

The tooth member 63 includes a block-shaped main body portion 80 and a pair of second tooth rows 62L formed of a plurality of second teeth 62. The tooth member 63 is formed by press forming such as sintering or forging. The tooth member 63 of this embodiment is, for example, a sintered body. Therefore, the pair of second tooth rows 62L and the body portion 80 can be formed integrally as a sintered body. The main body portion 80 integrally includes a first portion 81, a second portion 82 adjoining a rear side X1 of the first portion 81. The second portion 82 includes, as its rear end portion, a snap projection 83 projecting toward the rear side X1. In addition, the second portion 82 includes, as a lower end portion thereof, a tooth forming portion 84.

Referring to fig. 5 in which the tooth member 63 is viewed from the lower side Z2, the tooth forming portion 84 includes a pair of side surfaces 85 as both side surfaces in the left-right direction Y. The pair of side surfaces 85 extend parallel to each other at the tooth forming portion 84. The pair of side surfaces 85 extend in a direction parallel to the axial direction X. The side surface 85A of the right side Y1 is also a part of a right side surface that is an example of one side surface of the body 80. The side surface 85B of the left side Y2 is also a part of the left side surface as an example of the other side surface of the body 80.

The second tooth row 62L is provided on each of the pair of side surfaces 85 of the tooth forming portion 84. The second tooth row 62L of the right side Y1 is provided on the side surface 85A of the right side Y1. The second tooth row 62L of the left side Y2 is provided on the side surface 85B of the left side Y2. The second teeth 62 of each second tooth row 62L are teeth having a so-called transverse tooth shape having a tooth tip 86 and a tooth direction 87 extending in the vertical direction Z (see fig. 4). Each second tooth 62 of the second tooth row 62L of the right side Y1 projects from the side surface 85A of the right side Y1 toward the right side Y1 with its tooth tip 86A toward the right side Y1. The second tooth 62 of the second tooth row 62L of the left side Y2 projects from the side surface 85B of the left side Y2 toward the left side Y2 with its tooth tip 86B toward the left side Y2.

The plurality of second teeth 62 of the second tooth row 62L of the side surface 85A of the right side Y1 are arranged in parallel in the axial direction X at the predetermined pitch P described above. The plurality of second teeth 62 of the second tooth row 62L of the side surface 85B of the left side Y2 are also arranged in parallel in the axial direction X at a predetermined pitch P. In the axial direction X, the tooth crest 86A of the second tooth 62 of the second tooth row 62L on the right side Y1 is offset from the tooth crest 86B of the second tooth 62 of the second tooth row 62L on the left side Y2 by a distance L corresponding to half the pitch P. In other words, the pair of second tooth rows 62L is configured to be asymmetrical in the left-right direction Y.

When such a tooth member 63 is molded by sintering, the metal powder is pressed in the die by sintering. The tooth member 63 is formed such that the second teeth 62 undulate in the pressing direction (corresponding to the left-right direction Y). Here, unlike the tooth member 63 of the present embodiment, a comparative example is assumed in which a pair of tooth rows of the tooth member has a symmetrical shape in the left-right direction Y. In the gear member of the comparative example, the tooth tips of the tooth rows on the right side Y1 of the gear member are aligned with the tooth tips of the tooth rows on the left side Y2 in the axial direction X. Therefore, the difference in thickness between the tooth member and the tooth member is large between the top portion where the tooth crest is formed and the bottom portion where the tooth bottom is formed. That is, the thickness of the tooth member greatly varies in the axial direction X. The density corresponding to the compression ratio of the press-formed tooth member is not uniform in the direction in which the teeth are arranged. In detail, the density of the tooth members is higher at the top and lower at the bottom.

On the other hand, referring to fig. 5, when the distance L is smaller than the pitch P, the thickness W in the left-right direction Y can be made as uniform as possible at any position in the axial direction X. This can suppress variation in the density of the tooth forming portion 84 according to the position in the axial direction X. Therefore, the density of the second teeth 62 (tooth density) is stabilized, and the mechanical performance of the tooth member 63 such as the strength of the tooth forming portion 84 and the strength of the second teeth 62 (tooth strength) is improved.

In the present embodiment, the distance L corresponds to half of the pitch P, and therefore the thickness W of the tooth forming portion 84 in the left-right direction Y is substantially uniform at least between the tooth crest 86A of the second tooth 62 on the forefront X2 and the tooth crest 86B of the second tooth 62 on the rearmost X1. Therefore, it is possible to further suppress the density of the tooth members 63 formed by press forming from varying in accordance with the positions in the axial direction X.

Referring to fig. 4, the tooth member 63 is disposed on the upper side Z1 with respect to the outer peripheral surface 22B of the upper sheath 22 and on the front side X2 with respect to the tilt bolt 40. The outer peripheral surface 22B of the upper sheath 22 is also the bottom surface of the through hole 70A of the tooth plate 61. The support mechanism 64 is constituted by a pair of support shafts 89 and a pair of first guide holes 34B. The pair of support shafts 89 protrude from the first portion 81 of the body 80 of the gear member 63 to both outer sides in the left-right direction Y. The pair of first guide holes 34B are provided in the pair of extending portions 34 of the lower sheath 23, respectively. The pair of support shafts 89 have center axes 89A extending in the left-right direction Y. Each first guide hole 34B is an elongated hole extending in the axial direction X.

One support shaft 89 is inserted into each of the pair of first guide holes 34B. Thus, the pair of support shafts 89 are supported by the extension portions 34, respectively, and are movable in the axial direction X in a state of being parallel to the tilt bolt 40. The first portion 81 of the main body portion 80 of the tooth member 63 is supported by the pair of extending portions 34 via the pair of support shafts 89.

The pair of support shafts 89 may be provided separately from the gear member 63. In this case, the pair of support shafts 89 are configured to support the first portion 81 of the body portion 80 of the tooth member 63 by being inserted through a hole, not shown, that penetrates the tooth member 63 in the left-right direction Y. In relation to the guide mechanism 65, a support hole 34C, which is a circular hole, is formed in each of the facing surfaces 34A of the pair of extensions 34. In fig. 4, for convenience of explanation, only the support hole 34C of the extension 34 of the right side Y1 is shown.

The guide mechanism 65 includes a rod-shaped guide shaft 90 and a second guide hole 82A that is long in the vertical direction Z. The guide shaft 90 extends in the left-right direction Y. The second guide hole 82A is provided in the second portion 82 of the tooth member 63. Both ends of the guide shaft 90 in the left-right direction Y are inserted into the support holes 34C of the pair of extensions 34. Thereby, the guide shaft 90 is supported by the pair of extension portions 34 so as not to move in the vertical direction Z. The interlocking mechanism 66 includes a pushing member 91 and a releasing member 92. The pressing member 91 presses the tooth member 63 around the central axis 89A of the support shaft 89 so that the second teeth 62 mesh with the first teeth 60. The releasing member 92 drives the tooth member 63 so as to release the engagement of the second teeth 62 with the first teeth 60 against the pressing member 91.

In the interlocking mechanism 66, a locking hole 34D is formed in the facing surface 34A of the extension 34 of the right side Y1. The urging member 91 is, for example, a torsion spring. The pressing member 91 includes a first end portion 91A, a second end portion 91B, and a coil portion 91C. The first end portion 91A is locked to a locking hole 34D of the extension portion 34 provided on the right side Y1. The second end 91B pushes the second portion 82 of the tooth member 63 to the lower side Z2. Coil portion 91C is wound around tilt bolt 40 between first end portion 91A and second end portion 91B.

The release member 92 includes an annular main body 92A and a release projection 92B. The release projection 92B projects from the outer periphery of the main body 92A. The main body 92A has a through hole 92C penetrating the main body 92A in the left-right direction Y. The tilt bolt 40 is inserted through the through hole 92C (see fig. 3). The release member 92 is rotatable integrally with the tilt bolt 40. Specifically, an inner spline, not shown, is formed on the inner peripheral surface of the main body 92A. An outer spline, not shown, is formed on the outer periphery of the tilt bolt 40. The main body 92A is spline-fitted to the tilt bolt 40. The release projection 92B faces the engagement projection 83 of the second portion 82 of the tooth member 63 from the lower side Z2.

The operation of the tooth lock mechanism 8 will be described below. Fig. 6 is a schematic side view of the tooth lock mechanism 8 and shows a state in which the second tooth 62 is engaged with the first tooth 60. When the state of the steering apparatus 1 is the locked state, the second portion 82 of the main body portion 80 of the tooth member 63 is pressed to the lower side Z2 by the second end portion 91B of the pressing member 91, whereby the second teeth 62 of the tooth member 63 mesh with the first teeth 60 of the tooth plate 61 as shown in fig. 6.

As shown in fig. 7, which is a cross-sectional view taken along line VII-VII of fig. 6, the pair of second tooth rows 62L mesh with the pair of first tooth rows 60L. Specifically, in a state where the second row 62L of the right side Y1 is meshed with the first row 60L of the right side Y1, the second row 62L of the left side Y2 is meshed with the first row 60L of the left side Y2. Referring to fig. 6, when the operating member 41 is rotated to change the steering apparatus 1 from the locked state to the released state, the releasing member 92 rotates integrally with the tilt bolt 40, and the releasing projection 92B of the releasing member 92 moves to the upper side Z1. The release projection 92B moves to the upper side Z1, and thereby engages with the engagement projection 83.

When the operation member 41 is further rotated in the same direction as before, the release projection 92B pushes up the engagement projection 83 against the pressing member 91. At this time, the guide shaft 90 relatively moves to the lower side Z2 in the second guide hole 82A of the second portion 82 of the gear member 63. Thereby, the second portion 82 is guided to the upper side Z1. As a result, the second teeth 62 move to the upper side Z1, and as shown in fig. 8, which is a schematic side view of the tooth lock mechanism 8, the engagement between the second teeth 62 and the first teeth 60 is released.

In this way, in the released state, the upper sheath 22 is released from being fixed to the lower sheath 23 in the axial direction X by the tooth lock mechanism 8. Referring to fig. 8, conversely, when the operating member 41 is rotated to change from the release state to the lock state, the release member 92 rotates integrally with the tilt bolt 40, and the release projection 92B of the release member 92 moves toward the lower side Z2. The second portion 82 of the tooth member 63 having the engaging projection 83 is pressed by the pressing member 91. Therefore, the release projection 92B moves to the lower side Z2 in association with the movement to the lower side Z2. At this time, the guide shaft 90 is relatively moved to the upper side Z1 within the second guide hole 82A of the second portion 82, whereby the second portion 82 is guided to the lower side Z2. As a result, the second teeth 62 move to the lower side Z2, and the second teeth 62 of the pair of second tooth rows 62L mesh with the first teeth 60 of the pair of first tooth rows 60L from the vertical direction Z (see fig. 6).

In this way, in the locked state, the upper sheath 22 can be locked with respect to the lower sheath 23 in the axial direction X by the tooth lock mechanism 8. According to the present embodiment, as described above, referring to fig. 5, in the gear member 63, the tooth tip 86A of the second tooth 62 of the second tooth row 62L on the right side Y1 and the tooth tip 86B of the second tooth 62 of the second tooth row 62L on the left side Y2 are offset by the distance L in the axial direction X. Therefore, the strength of the second teeth 62 is improved. Therefore, in the structure in which the expansion and contraction of the column jacket 4 is restricted by the engagement of the second teeth 62 with the first teeth 60, the engagement of the second teeth 62 with the first teeth 60 can be stabilized.

Referring to fig. 1, at the time of a vehicle collision, a secondary collision occurs in which the driver collides with the steering member 11 after a primary collision in which the vehicle collides with an obstacle. In the secondary collision, the steering member 11 receives an impact at least in the axial direction X due to the reaction force generated by the deployment of the airbag incorporated in the steering member 11 and the collision of the driver with the airbag. However, in the steering device 1, in addition to the position of the column jacket 4 being held by the fastening mechanism 7, the position of the column jacket 4 in the axial direction X and the position of the steering member 11 can be firmly held by the tooth lock mechanism 8. Such retention of the column jacket 4 by the tooth lock mechanism 8 is referred to as positive locking (positive lock).

By the reliable locking, the restraint of the upper sheath 22 with respect to the lower sheath 23 can be stabilized before the guide shaft 90 is sheared at the time of the secondary collision, i.e., at the initial stage of the secondary collision. In other words, the initial restraint at the time of the secondary collision can be stabilized. As a result, the guide shaft 90 is sheared by the impact in the axial direction X without being deviated, and the movement of the upper jacket 22 is allowed. In this way, the toothed member 63 moves together with the toothed plate 61 and the upper jacket 22 towards the front side X2, whereby the column jacket 4 contracts. The impact at the time of the secondary collision is absorbed by a load (referred to as a shear load) generated when the guide shaft 90 is sheared and the sliding of the upper jacket 22 with respect to the lower jacket 23.

As described above, referring to fig. 6, the engagement strength of the second teeth 62 and the first teeth 60 is stabilized. Therefore, the guide shaft 90 can stably receive the impact at the time of the secondary collision, and thus can generate a stable shear load. Therefore, the impact performance such as impact absorption performance at the time of a secondary impact can be stabilized. Next, a modified example of the present embodiment will be explained.

Fig. 9 is a view of the tooth member 63P according to the modification of the present embodiment, as viewed from the lower side Z2. Fig. 10 is a view of the tooth member 63P as viewed from the rear side X1. In fig. 9 and 10, the same components as those described so far are denoted by the same reference numerals, and the description thereof is omitted. Referring to fig. 9 and 10, the main body portion 80 of the tooth member 63P includes, as its outer surface, a pair of side surfaces 95, and a lower surface 96 and an upper surface 97 that connect the side surfaces 95 to each other.

The pair of side surfaces 95 face each other in a direction parallel to the left-right direction Y. A direction in which the pair of side surfaces 95 face each other (a direction parallel to the left-right direction Y) is referred to as an opposing direction F. The pair of side surfaces 95 of the main body portion 80 includes a first surface (the side surface 85 of the tooth forming portion 84) and a second surface 98, respectively. The first surface is provided with a second tooth row 62L. The second surface 98 is located outside the body 80 with respect to the upper surface 85 in the facing direction F. The first face of right side Y1 corresponds to side face 85A of right side Y1. The first surface of the left side Y2 corresponds to the side surface 85B of the left side Y2. The second surface 98A of the right side Y1 is located on the right side Y1 with respect to the side surface 85A of the right side Y1 of the tooth forming portion 84. The second surface 98B of the left side Y2 is located on the left side Y2 with respect to the side surface 85B of the left side Y2 of the tooth forming portion 84.

Lower surface 96 includes a coupling surface 99 and a lower surface 100 of tooth forming portion 84. The coupling surface 99 couples each side surface 85 of the tooth forming portion 84 to the corresponding second surface 98. The coupling surface 99 and the lower surface 100 of the tooth forming portion 84 extend in the facing direction F. The second teeth 62 of each second tooth row 62L project from the corresponding side surface 85 of the tooth forming portion 84 toward the tooth crest 86 in the opposing direction F. Specifically, each second tooth 62 of the second tooth row 62L of the right side Y1 projects from the side surface 85A of the right side Y1 toward the right side Y1, and its tooth tip 86A faces the right side Y1. The second tooth 62 of the second tooth row 62L of the left side Y2 projects from the side face 85B of the left side Y2 toward the left side Y2 with its tooth crest 86B toward the left side Y2. The second teeth 62 of each second tooth row 62L are connected to the corresponding connection surface 99.

In the opposing direction F, the distance W1 between the tooth crest 86A of the second tooth 62 on the side 85A of the right side Y1 and the tooth crest 86B of the second tooth 62 on the side 85B of the left side Y2 is equal to the distance W2 between the second faces 98. The tooth tops 86 of the second teeth 62 of the pair of second tooth rows 62L are located at the same positions as the second surfaces 98 of the corresponding side surfaces 95 in the opposing direction F, respectively. Specifically, the tooth tip 86A of the second tooth row 62L of the right side Y1 is located at the same position in the facing direction F as the second surface 98A of the right side Y1. The tooth top 86B of the second tooth row 62L of the left side Y2 is located at the same position in the opposing direction F as the second surface 98B of the left side Y2. In other words, no step is provided between the tooth crest 86 of each second tooth 62 of the pair of second tooth rows 62L and the second surface 98 of the corresponding side surface 95 as viewed in the axial direction X.

According to this modification, the tooth tips 86 of the second teeth 62 of the pair of second tooth rows 62L are located at the same positions as the second surfaces 98 of the pair of side surfaces 95 in the opposing direction F. Therefore, the thickness of the tooth members 63P in the facing direction F can be made constant as much as possible. Therefore, the shape of the tooth member 63P is simplified, and therefore the tooth member 63P can be easily formed by press forming. In detail, when the tooth member 63P is molded by sintering, the structure of a die used for pressurizing the powder metal at the time of sintering (in other words, a die used at the time of press molding) can be simplified. This facilitates deformation of the tooth member 63P. The cost of the mold can be reduced by simplifying the structure of the mold used in the press molding.

The present invention is not limited to the embodiments described above, and various modifications can be made within the scope described in the claims. For example, the steering device 1 is not limited to the tooth lock mechanism 8, and may be provided with a tooth lock mechanism having a different structure. For example, the tooth lock mechanism may be a structure that does not include the guide mechanism 65. In this case, the pair of extending portions 34 are provided with support holes for restricting the movement of the support shaft 89 in the axial direction X, instead of the first guide holes 34B through which the support shaft 89 of the gear member 63 is inserted, and the support shaft 89 is sheared to contract the column sheath 4 at the time of a secondary collision.

In the

gear members

63, 63P, the pitch P in the axial direction X of the second tooth row 62L of the right side Y1 and the second tooth row 62L of the left side Y2 may be different. However, in this case, the plurality of first teeth 60 of the first tooth row 60L of the right side Y1 also need to be arranged in the axial direction X at a predetermined pitch equal to the second tooth row 62L of the right side Y1. The plurality of first teeth 60 of the first tooth row 60L of the left side Y2 need to be juxtaposed in the axial direction X at the same pitch as the second tooth row 62L of the left side Y2.

The

tooth members

63, 63P may include one second tooth 62 on each side surface 85, instead of the second tooth row 62L.

Claims

1. A steering device, comprising:

a steering shaft, one end of which is connected with a steering control component and can extend and retract along the axial direction;

a column jacket that has an upper jacket that holds the steering shaft on the steering member side in the axial direction and a lower jacket that holds the steering shaft on a side opposite to the steering member side in the axial direction, and is capable of telescoping in the axial direction together with the steering shaft by movement of the upper jacket relative to the lower jacket in the axial direction;

a bracket that supports the lower jacket and is fixed to a vehicle body;

an operation member that is operated to restrict expansion and contraction of the column jacket;

a pair of first tooth rows that are formed by a plurality of first teeth extending in parallel and are movable integrally with the upper jacket in the axial direction, the plurality of first teeth having a tooth direction extending in a direction intersecting the axial direction and being arranged at a predetermined pitch in the axial direction;

a tooth member including a block-shaped main body portion supported by the under jacket and a pair of second teeth provided on a pair of side surfaces of the main body portion extending in parallel to each other, the tooth member being movable in accordance with an operation of the operating member to mesh the pair of second teeth with the pair of first tooth rows, and being formed by press molding,

the pair of second teeth are formed such that tooth crests thereof are shifted from each other by a distance smaller than the predetermined pitch.

2. The steering device according to claim 1,

the tooth member includes a sintered body.

3. The steering device according to claim 1,

the distance corresponds to half of the prescribed pitch.

4. The steering device according to claim 1,

the pair of second teeth have tooth tops located at the same positions as the pair of side surfaces in the opposing direction of the pair of side surfaces.

5. A tooth member, comprising:

a block-shaped main body portion; and

a pair of teeth provided at least one on each of a first surface of a pair of side surfaces extending in parallel with each other on the body and including the first surface and a second surface located on an outer side of the body than the first surface in a facing direction of the pair of side surfaces,

the tooth tops of the pair of tooth parts are shifted from each other, and the pair of tooth parts are formed by press forming,

tooth tops of the pair of tooth portions are located at the same position as the second surface of the pair of side surfaces in the opposing direction of the pair of side surfaces.