CN107571908B - Steering device - Google Patents

Abstract

The invention provides a steering device. The steering device includes a fastening mechanism for fastening and holding the upper cover by the lower cover. In the fastened state of the fastening mechanism, the first tooth element on the upper sleeve side meshes with the second tooth element on the lower sleeve side. The second tooth member is connected to the lower sleeve by a guide shaft (connecting member) that can be broken when a secondary collision occurs. When a secondary collision is received in the released state of the fastening mechanism, a second engagement portion (drive member) that moves in the column axial direction integrally with the upper sleeve comes into contact with the second tooth member in the released state, breaks the guide shaft, and deforms the impact absorbing member via the second tooth member to absorb the impact.

Description

Steering device

Technical Field

The present invention relates to a steering device.

Background

In the steering column for an automobile of japanese patent application laid-open No. 2011-516323, an upper adjusting unit is disposed between a pair of side plates of a lower support unit. The fastening mechanism for fastening the pair of side plates of the support unit includes a fastening bolt inserted through the side plates. A locking member is disposed on the fastening bolt. An object lock member that engages with the lock member is integrally formed on a fracture plate fixed to the adjustment unit. When the fastening mechanism is fastened, the locking member engages with the target locking member to lock the position of the adjustment unit with respect to the support unit.

When a secondary collision is received in a fastened state of the fastening mechanism (a state in which the lock member is engaged with the target lock member), the upper adjustment unit slides with respect to the support unit. Thus, the object lock member breaks the rupture plate, and absorbs the impact at the time of a secondary collision.

However, the secondary collision may occur not only in the fastened state of the fastening mechanism but also in the unfastened state of the fastening mechanism (the state in which the engagement of the lock member with the object lock member is released). In contrast, in japanese patent application laid-open No. 2011-516323, the impact at the time of receiving a secondary collision cannot be absorbed in the unlocked state. Therefore, when a secondary collision is received in the unfastened state, it is considered to use an impact absorbing member separately provided from the rupture plate to absorb the impact. However, in this case, the structure becomes complicated.

Disclosure of Invention

An object of the present invention is to provide a steering device that can absorb an impact at the time of a secondary collision regardless of a fastened state (even in a fastened released state) by a simple configuration.

A steering device according to an aspect of the present invention is a steering device including: a steering shaft that is capable of extending and retracting in the axial direction of the column; a column sleeve including a lower sleeve and an upper sleeve fitted to the lower sleeve, the column sleeve rotatably supporting the steering shaft and being extendable in the column axial direction during telescopic adjustment; a fastening mechanism for fastening and holding the upper sleeve by the lower sleeve; an impact absorbing member supported by the lower case and absorbing an impact by deformation; a first tooth member that moves in the column axial direction integrally with the upper sleeve; a second tooth member that is brought into a state of engagement with the first tooth member when the fastening mechanism is fastened, and is brought into a state of disengagement that releases the engagement when the fastening mechanism is released; a connecting member that connects the second tooth member and the lower sleeve and is breakable when a secondary collision occurs; and a driving member that is movable in the column axial direction integrally with the upper cover, and that, when a secondary collision is received in a released state of the fastening mechanism, contacts the second tooth member in the released state of engagement to break the connecting member, and that deforms the impact absorbing member via the second tooth member, wherein the steering device is configured such that, when a secondary collision is received in the fastened state of the fastening mechanism, the second tooth member in the engaged state breaks the connecting member and deforms the impact absorbing member.

Drawings

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

fig. 1 is a schematic side view of a steering device of a first embodiment of the present invention.

Fig. 2 is a schematic perspective view of the steering device of the first embodiment.

Fig. 3 is a sectional view III-III of fig. 1.

Fig. 4 is an exploded perspective view of the steering device according to the first embodiment, mainly showing the structures of the shock absorbing mechanism and the tooth lock mechanism.

Fig. 5 is a side view of a main portion of the steering device of the first embodiment, mainly showing a structure for supporting the impact absorbing mechanism.

Fig. 6 is a schematic plan view of the impact absorbing member and the lower cover in the first embodiment.

Fig. 7 is a perspective view of the configuration of the periphery of the tooth lock mechanism in the first embodiment.

Fig. 8 is a sectional view VIII-VIII of fig. 7, and shows the configuration of the periphery of the guide shaft broken when a secondary collision is received.

Fig. 9 is a sectional view IX-IX of fig. 7, showing (a) an engagement state of the tooth lock mechanism, and (b) an engagement release state of the tooth lock mechanism.

Fig. 10 is an enlarged perspective view of the second tooth member.

Fig. 11 is a sectional view of the structure of the periphery of the guide shaft that is broken when a secondary collision occurs. (a) Is a sectional view taken from XIa to XIa in FIG. 9 (a), and (b) is a sectional view taken from XIb to XIb in FIG. 9 (b).

Fig. 12 (a) is a perspective view of the second support member in the first embodiment, (b) is a perspective view of the second support member viewed from a different angle from (a), and (c) is a rear view of the second support member (view viewed from the lower side in the column axial direction).

Fig. 13 (a) and (b) are partially sectional side views of the structure of the periphery of the tooth lock mechanism in the first embodiment. (a) Showing an engaged state (locked state), (b) showing an engaged state (unlocked state).

Fig. 14 is a schematic diagram of the configuration of the periphery of the impact absorbing mechanism as viewed from the column axial lower side in the first embodiment.

Fig. 15 is a partially broken schematic side view of the impact absorbing mechanism in the engaged state in the second embodiment when a secondary collision occurs.

Fig. 16 is a partially broken schematic side view of the impact absorbing mechanism in the second embodiment when a secondary collision is received in the engagement released state.

Fig. 17 (a) and (b) are sectional views of the structure around the tooth lock mechanism of the steering device according to the second embodiment of the present invention, where (a) shows an engaged state (locked state) and (b) shows an disengaged state (unlocked state).

Fig. 18 is a schematic sectional view of the configuration of the periphery of the projection of the driving member in the second embodiment.

Fig. 19 (a), (b), and (c) are cross-sectional views of the structure around the guide shaft that is broken at the time of a secondary collision in the third, fourth, and fifth embodiments of the present invention, respectively.

Fig. 20 (a) and (b) are schematic side views of a tooth lock structure of a steering device according to a sixth embodiment of the present invention, where (a) shows an engaged state (locked state), (b) shows an engaged state (unlocked state), (c) is a schematic diagram showing a relationship between a shearing direction and a column axial direction in the engaged state, and (d) is a schematic diagram showing a relationship between the shearing direction and the column axial direction in the disengaged state.

Detailed Description

Hereinafter, embodiments embodying the present invention will be described with reference to the drawings. Fig. 1 is a schematic side view of a steering device 1 of a first 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, and the right side of the drawing is the rear side of the vehicle body 2. In fig. 1, 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. Fig. 2 is a perspective view of the steering device 1.

Referring to fig. 1, a steering device 1 mainly includes a steering shaft 3, a column cover 4, a lower bracket 5, an upper bracket 6, a fastening mechanism 7, an impact absorbing mechanism 8, and a tooth lock mechanism 9. The extending direction of the steering shaft 3 is a column axial direction X. A steering member 10 such as a steering wheel is coupled to one end 3a (upper end in the column axial direction X) of the steering shaft 3. The other end 3b of the steering shaft 3 (the lower end in the column axial direction X) is connected to a steering mechanism 14 via a universal joint 11, an intermediate shaft 12, and a universal joint 13 in this order. The steering mechanism 14 is, for example, a rack and pinion mechanism that steers a steering wheel (not shown) in accordance with the transmitted steering rotation of the steering member 10.

The steering shaft 3 has a cylindrical upper shaft 3U and a cylindrical lower shaft 3L. The upper shaft 3U and the lower shaft 3L are fitted to each other so as to be slidable relative to each other by spline fitting or serration fitting, for example. The steering member 10 is coupled to one end (upper end in the column axial direction X) of the upper shaft 3U. The steering shaft 3 can be extended and retracted in the column axial direction X by movement of the upper shaft 3U relative to the lower shaft 3L in the column axial direction X. Here, the upper side and the lower side in the column axial direction X are referred to as a column axial upper side XU and a column axial lower side XL, respectively.

The column jacket 4 is a hollow body extending in the column axial direction X. The column jacket 4 comprises an upper jacket 15 and a lower jacket 16. The upper casing 15 is fitted to the lower casing 16 so as to be slidable in the column axial direction X. The string casing 4 can be extended and retracted in the string axial direction X. The steering shaft 3 is inserted into the column cover 4, and is rotatably supported by the column cover 4 via a plurality of bearings 17 and 18. Specifically, the upper shaft 3U is rotatably supported by the upper sleeve 15 via a bearing 17. The lower sleeve 16 rotatably supports the lower shaft 3L via a bearing 18.

The upper sleeve 15 is coupled to the upper shaft 3U via a bearing 17. The lower sleeve 16 is coupled to the lower shaft 3L via a bearing 18. Therefore, the upper casing 15 moves in the tubular string axial direction X relative to the lower casing 16. Thereby, the column cover 4 extends and contracts in the column axial direction X together with the steering shaft 3.

The expansion and contraction of the steering shaft 3 and the column cover 4 are referred to as "expansion and contraction". The adjustment of the position of the steering member 10 in the column axial direction X by expansion and contraction is referred to as expansion and contraction adjustment. The lower bracket 5 includes: a fixed bracket 5A fixed to the vehicle body 2, and a movable bracket 5B fixed to a lower portion of the lower sleeve 16 in the column axial direction X. The movable bracket 5B is rotatably supported via a center axis 5C extending in a direction orthogonal to the column axial direction X (a left-right direction of the vehicle body 2, a direction orthogonal to the plane of the paper in fig. 1).

The column cover 4 and the steering shaft 3 can rotate up and down about the center axis 5C. The rotation is referred to as "pitching" and the movement direction, which is an approximately vertical direction around the central axis 5C, is referred to as a pitching direction Y. The vertical adjustment by the pitching of the steering member 10 is referred to as pitching adjustment. The upper side of the pitch direction Y is denoted by the pitch direction upper side YU, and the lower side of the pitch direction Y is denoted by the pitch direction lower side YL.

As shown in fig. 2, the direction orthogonal to both the column axial direction X and the pitching direction Y corresponds to the left-right direction Z of the vehicle body 2. The upper bracket 6 includes a web 20 and a pair of side plates 19. The pair of side plates 19 face each other in the left-right direction Z via the column jacket 4. The connecting plate 20 connects upper end portions of the pair of side plates 19 to each other. As an integral part of the upper bracket 6, a groove shape open downward is formed as viewed in the column axial direction X. The linking plate 20 has portions extending toward both sides of the pair of side plates 19, and the linking plate 20 is fixed to the vehicle body 2 using bolts (not shown) inserted through the portions (see fig. 1). Thereby, the upper bracket 6 is fixed to the vehicle body 2.

As shown in fig. 2, arc-shaped pitching grooves 21 centered on the central axis 5C of pitching are formed in the pair of side plates 19. The lower casing 16 includes: a slit 22 extending in the column axial direction X, and a pair of fastened portions 23 disposed on both sides of the slit 22. The slit 22 is formed in a portion of the lower casing 16 on the upper side XU in the column axial direction. The pair of fastened portions 23 are plate-shaped portions facing each other in the left-right direction Z at portions of the lower sleeve 16 on the upper XU in the column axial direction with the slit 22 interposed therebetween. The pair of fastened portions 23 are clamped and fastened, and the upper jacket 15 is fastened by the lower jacket 16 which is elastically reduced in diameter.

Fig. 3 is a sectional view III-III of fig. 1. As shown in fig. 3, the pair of side plates 19 of the upper bracket 6 includes an outer side surface 19a and an inner side surface 19b, respectively. Shaft insertion holes 24 each formed of a circular hole and penetrating the fastened portion 23 in the left-right direction Z are formed in the pair of fastened portions 23. The pair of fastened portions 23, which are plate-shaped, include outer side surfaces 23a and inner side surfaces 23b, respectively. The outer surface 23a of each fastened portion 23 faces the inner surface 19b of the corresponding side plate 19 of the upper bracket 6.

A pair of flat portions 15b extending parallel to each other in a predetermined range in the column axial direction X (a direction perpendicular to the paper surface in fig. 3) is provided in a part of the outer peripheral surface 15a of the upper jacket 15 in the circumferential direction. A plate-like first tooth member 60 of the tooth lock mechanism 9 is fixed to one flat portion 15 b. End surfaces 60a (in the left-right direction Z) on both sides of the first tooth member 60 respectively face the inner surfaces 23b of the pair of fastened parts 23 in proximity thereto.

At the time of expansion adjustment, the inner side surfaces 23b of the pair of fastened portions 23 guide the movement of the upper sleeve 15 in the column axial direction X via the pair of end surfaces 60a of the first tooth member 60, and restrict the rotation of the upper sleeve 15 with respect to the lower sleeve 16. Next, the fastening mechanism 7 will be explained. The fastening mechanism 7 is a mechanism for locking or unlocking the position of the steering member 10 (see fig. 1) in which the pitch adjustment and the telescopic adjustment have been completed.

The fastening mechanism 7 includes: a tightening shaft 25, an operating lever 26, an annular cam 27, one tightening member 28 as an annular cam follower, a nut 29, another tightening member 30, and an insertion member 31. The cam 27, one fastening member 28, the nut 29, the other fastening member 30, and the insertion member 31 are supported by the outer periphery of the fastening shaft 25. The fastening shaft 25 is formed of a bolt inserted through the vertically movable grooves 21 of the side plates 19 of the upper bracket 6 and the shaft insertion holes 24 of the fastened portions 23 of the lower case 16. The fastening shaft 25 is supported by the two side plates 19. A large-diameter head 25a provided at one end of the fastening shaft 25 is fixed to be rotatable integrally with the operating lever 26.

The cam 27 and the cam follower (one fastening member 28) are interposed between the head portion 25a of the fastening shaft 25 and the one side plate 19, and constitute a force conversion mechanism that converts the operation torque of the operation lever 26 into an axial force of the fastening shaft 25 (fastening force for fastening the pair of side plates 19). The cam 27 is connected to the operating lever 26 so as to be rotatable integrally therewith, and is restricted from moving relative to the tightening shaft 25 in a tightening axial direction J, which is a central axial direction of the tightening shaft 25. The cam follower (one fastening member 28) is engaged with the cam 27 in the form of a cam to fasten the one side plate 19.

The one fastening member 28 (cam follower) and the other fastening member 30 have: fastening plate portions 28a, 30a for fastening the respective side plates 19, and protrusion portions 28b, 30b for fitting into the respective rocking grooves 21. The rotation of the fastening members 28 and 30 is regulated by the fitting of the protrusions 28b and 30b to the corresponding rocking grooves 21. Both fastening members 28, 30 are supported by the fastening shaft 25 so as to be movable in the fastening axial direction J.

The nut 29 is screwed to the screw portion 25b of the other end of the fastening shaft 25. The insertion member 31 is interposed between the other fastening member 30 and the nut 29. The insertion part 31 includes a washer 32 and a needle bearing 33. The cam 27 rotates relative to one fastening member 28 (cam follower) in accordance with the rotation of the operating lever 26 toward the locking side. Thereby, one fastening member 28 moves in the fastening axial direction J, and (the fastening plate portions 28a, 30a of) the pair of side plates 19 of the upper bracket 6 are clamped and fastened between both fastening members 28, 30.

Thereby, each side plate 19 of the upper bracket 6 fastens the corresponding fastened portion 23 of the lower jacket 16. As a result, the movement of the lower sleeve 16 in the pitch direction Y is restricted by the frictional engagement force between each side plate 19 and the corresponding fastened portion 23, and pitch lock is realized. By fastening both the fastened portions 23, the upper case 15 is fastened by the portion of the lower case 16 on the upper side XU in the column axial direction. Thus, the movement of the upper sleeve 15 in the column axial direction X is restricted by the frictional engagement force between the two sleeves 15, 16, thereby achieving expansion and contraction.

Fig. 4 is a schematic exploded perspective view of the shock absorbing mechanism 8 and the tooth lock mechanism 9. As shown in fig. 4, the shock absorbing mechanism 8 includes a shock absorbing member 40 and a guide restricting mechanism 50. The impact absorbing member 40 moves and deforms when a secondary collision occurs, and absorbs the impact of the secondary collision. The guide restricting mechanism 50 guides and restricts the deformation of the impact absorbing member 40. The impact absorbing member 40 includes a pair of first plate portions 41, a pair of second plate portions 42, a pair of folded portions 43, and a moving portion 44. The pair of first plate portions 41 includes a fixed portion 45 and a deformation scheduled portion 46.

The pair of first plate portions 41 of the impact absorbing member 40 are connected to the corresponding second plate portions 42 via the corresponding folded portions 43. The moving portion 44 functions as a connecting portion that connects the lower ends of the second plate portion 42 in the column axial direction X. Upon receiving a secondary collision, the moving portion 44 as a coupling portion moves integrally with the upper jacket 15 toward the column axial lower side XL. The tooth lock mechanism 9 includes a first tooth member 60, a second tooth member 70, a guide mechanism 80, and a link mechanism 90. The first tooth member 60 is fixed to the upper casing 15. The second tooth member 70 engages with the first tooth member 60. The guide mechanism 80 guides the second tooth member 70. The link mechanism 90 links the movement of the second tooth member 70 with the rotation of the fastening shaft 25.

The guide restricting mechanism 50 of the shock absorbing mechanism 8 includes a pair of guide restricting surfaces 51 and a guide restricting member 52. The pair of guide restricting surfaces 51 are provided on the first gear member 60 and face the pair of second plate portions 42 in the pitch direction Y. The pair of guide restricting surfaces 51 of the first tooth member 60 extend parallel to the column axial direction X. Upon receiving a secondary collision, the pair of guide restricting surfaces 51 receives the second plate portion 42 that moves integrally with the moving portion 44, and guides the parallel movement of the second plate portion 42 relative to the first plate portion 41 toward the column axial direction lower side XL. In other words, the pair of guide restricting surfaces 51 guide the movement of the moving portion 44 toward the column axial direction lower side XL while maintaining the second plate portion 42, which has an increased length in the column axial direction X, in parallel with the first plate portion 41 at the time of a secondary collision.

The guide restricting member 52 includes a pair of guide restricting plates 53 and a coupling portion 54. The coupling portion 54 includes an upper plate 541 and a pair of side plates 542, and is formed in a groove shape open downward. The pair of guide restricting plates 53 extend laterally (in the left-right direction Z) from a pair of open ends of the connecting portion 54 which is formed in a groove shape. Fig. 5 is a side view of a main portion of the steering device 1, and mainly shows a configuration of supporting the impact absorbing mechanism 8. As shown in fig. 4 and 5, the pair of guide regulating plates 53 of the guide regulating member 52 are arranged in parallel with the corresponding guide regulating surfaces 51, respectively. The pair of guide restricting plates 53 are arranged to cover the corresponding first plate portions 41 of the shock absorbing member 40 from the outside, respectively.

Each guide regulation plate 53 has an upper end 53a and a lower end 53b in the column axial direction X. As shown in fig. 5, each guide restricting plate 53 has an outer surface 53d and an inner surface 53c which is a surface on the lower cover 16 side (the shock absorbing member 40 side). As shown in fig. 4, a fixed portion 53e extending outward in the lateral direction is formed at the lower end 53b of each guide regulating plate 53. Each fixed portion 53e is formed with a screw insertion hole 53 f.

The pair of first plate portions 41 of the impact absorbing member 40 are connected to the corresponding second plate portions 42 via the corresponding folded portions 43. The moving portion 44 (connecting portion) extends in the left-right direction Z so as to connect the lower ends of the second plate portion 42 in the column axial direction X to each other. Upon receiving a secondary collision, the moving portion 44 moves integrally with the upper jacket 15 toward the column axial lower side XL. The pair of first plate portions 41 extend parallel to the column axial direction X. The pair of first plate portions 41 are spaced apart in the left-right direction Z. The pair of second plate portions 42 extends parallel to the column axial direction X. The pair of second plate portions 42 is spaced apart in the left-right direction Z. Each first plate portion 41 is spaced from the corresponding second plate portion 42 in the pitch direction Y.

Fig. 6 is a schematic plan view of the shock absorbing member 40 and the lower shell 16. As shown in fig. 5 and 6, each first plate portion 41 has an upper end 41a and a lower end 41b in the column axial direction X. As shown in fig. 5, each first plate portion 41 has an outer surface 41d and an inner surface 41c which is a surface on the lower case 16 side (the shock absorbing member 40 side). As shown in fig. 6, a fixed portion 45 including an extension portion extending laterally is provided at the lower end 41b of each first plate portion 41. Each fixed portion 45 is formed with a screw insertion hole 45 a.

As shown in fig. 4, the lower sleeve 16 has a pair of wall portions 16c on both sides of the slit 22 at positions lower than the pair of fastened portions 23 in the column axial direction XL. The pair of wall portions 16c extend parallel to the column axial direction X and protrude upward in the pitching direction YU. The height of the pair of wall portions 16c is lower than the height of the pair of fastened portions 23 in the pitching direction Y. The lower cover 16 has a pair of fixing portions 16e formed by bosses protruding from the upper surfaces 16d (surfaces of the upper sides YU in the pitch direction) of the pair of wall portions 16 c. Each fixing portion 16e is formed with a screw hole 16 f.

As shown in fig. 5, the pair of fixing members 34 each formed of a fixing screw is inserted through the screw insertion hole 53f of the fixed portion 53e of the corresponding guide regulating plate 53 of the guide regulating member 52 and the screw insertion hole 45a of the fixed portion 45 of the first plate portion 41 of the impact absorbing member 40, and screwed into the screw hole 16f of the fixing portion 16e of the lower case 16. That is, the fixed portion 53e of the lower end 53b of each guide restricting plate 53 in the column axial direction X and the fixed portion 45 of the lower end 41b of the corresponding first plate portion 41 of the shock absorbing member 40 in the column axial direction X are fixed by being fastened together to the lower sleeve 16.

As shown in fig. 6, each first plate portion 41 includes a predetermined deformation portion 46 extending from the upper end 41a toward the column axial direction lower side XL. The scheduled deforming portion 46 includes, in terms of the width in the left-right direction Z, a small-width portion 46a, a large-width portion 46b, and a width changing portion 46 c. The small width portion 46a is adjacent to the upper end 41a and has a predetermined width. The large width portion 46b is adjacent to the lower end 41b and has a predetermined width wider than the small width portion 46 a. The width changing portion 46c is interposed between the small width portion 46a and the large width portion 46b, and the width thereof increases toward the large width portion 46 b.

A slit 47 extending in the column axial direction X is formed between the pair of first plate portions 41 in the left-right direction Z. Each guide limiting plate 53 is disposed so as to cover the corresponding first plate portion 41, and each guide limiting plate 53 limits the movement of the first plate portion 41 toward the upper side YU in the pitching direction when a secondary collision occurs. In the present embodiment, the width-varied portion 46c is folded and deformed near the end of the shock-absorbing stroke of the upper jacket 15 at the time of a secondary collision, and the shock-absorbing load increases. In the present embodiment, the small-width portion 46a and the width-varying portion 46c are folded and deformed when a secondary collision occurs, but the folded and deformed portions may be formed in the large-width portion 46 b. That is, by setting the lengths of the small width portion 46a, the large width portion 46b, and the width varying portion 46c in the column axial direction X, the impact absorption characteristics of the impact absorbing member 40 at the time of a secondary collision can be changed.

The tooth lock mechanism 9 is a mechanism for engaging the teeth with each other at the time of fastening by the fastening mechanism 7 in order to stabilize the initial restraint in the expansion and contraction direction at the time of a secondary collision (in other words, in order to hold the expansion and contraction position of the upper cover 15 at the time of initial collision with a secondary collision). Fig. 7 is a perspective view of the configuration of the periphery of the tooth lock mechanism 9. Fig. 13 (a) and (b) are partially sectional side views of the structure of the periphery of the tooth lock mechanism 9. Fig. 13 (a) shows the engaged state (locked state) of the tooth lock mechanism 9. Fig. 13 (b) shows an engagement released state (lock released state).

As shown in fig. 4, 7, and 13 (a), the tooth lock mechanism includes a first tooth member 60, a second tooth member 70, a guide mechanism 80, and a link mechanism 90. The first tooth member 60 will be explained. As shown in fig. 4, the first tooth member 60 is fixed to the flat portion 15b of the outer peripheral surface 15a of the upper cover 15 by welding or the like. The first tooth member 60 is formed using a plate member of a rectangular plate shape extending long in the column axial direction X.

The first tooth member 60 includes a pair of end surfaces 60a (see fig. 3) in the lateral direction Z (fastening axial direction J), an upper end 60b and a lower end 60c (see fig. 4) in the column axial direction X, a front surface 60d, and a back surface 60e (see fig. 3). The back surface 60e is a surface opposite to the surface 60d and is along the flat portion 15b of the upper cover 15. As shown in fig. 13 (a), the first tooth member 60 includes a through groove 61 and a pair of first tooth rows 62L. The through groove 61 penetrates the front surface 60d and the back surface 60e and extends in the column axial direction X. The pair of first tooth rows 62L are provided in the through groove 61. The upper case 15 has a slit 15c communicating with the through groove 61 and extending in the column axial direction X.

As shown in fig. 4 and 13 (a), the through groove 61 has a pair of inner wall surfaces extending in the column axial direction X and facing each other in the fastening axial direction J. A pair of first tooth rows 62L including a plurality of first teeth 62 aligned in the column axial direction X are formed on the pair of inner wall surfaces, respectively. As shown in fig. 4, the crests of the first teeth 62 of the pair of first tooth rows 62L face each other in the fastening axial direction J. The tooth trace direction D of the first teeth 62 (corresponding to the tooth width direction) extends in the depth direction of the through groove 61 so as to be orthogonal to both the column axial direction X and the tightening axial direction J.

The pair of guide regulating surfaces 51 of the guide regulating mechanism 50 of the shock absorbing mechanism 8 are disposed on both sides across the through groove 61 in the left-right direction Z (fastening axial direction J) on the surface 60d of the first tooth member 60. The first tooth member 60 may be fixed to the outer peripheral surface of the upper cover 15 by a bolt or the like, not shown. Alternatively, the first tooth member 60 may be formed integrally with the upper shell 15 from one material.

Next, the second tooth member 70 will be explained. Fig. 10 is an enlarged perspective view of the second tooth member 70. As shown in fig. 10, the second tooth member 70 includes a main body portion 73 and a tooth forming portion 75. The main body 73 includes a receiving portion 71 and a driving portion 72. The tooth forming portion 75 is provided to extend from the main body portion 73, and a second tooth 74 is formed at a position spaced apart from the received portion 71. As shown in fig. 13 (a), the main body 73 has a substantially rectangular plate shape in a side view (i.e., as viewed in the left-right direction Z). The main body 73 includes: an upper surface 73a which is a surface on the upper side YU in the pitching direction, a lower surface 73b which is a surface on the lower side YL in the pitching direction, and a pair of side surfaces 73c (only one side surface 73c is shown in fig. 4) which are opposed to each other in the left-right direction Z. The body 73 is formed with a hole 78 formed by a through hole penetrating the pair of side surfaces 73 c.

As shown in fig. 14, a gap is provided between the upper surface 73a of the body 73 and the upper plate 541 of the coupling portion 54 of the guide restricting member 52. The upper plate 541 abuts against the upper surface 73a of the body 73 at the time of a secondary collision, thereby restricting floating of the second tooth member 70 in the lower XL in the column axial direction. A predetermined amount of clearance is provided between each side surface 73c of the body 73 and the corresponding side plate 542 of the coupling portion 54 of the guide regulating member 52.

As shown in fig. 13 (a), the receiving portion 71 is formed of a curved convex portion provided at the lower end of the body portion 73 in the column axial direction X on the lower surface 73 b. As shown in fig. 13 (a) and 14, the receiving portion 71 is placed on a receiving surface 44a (corresponding to an upper surface) provided on the moving portion 44 of the impact absorbing member 40 constituting the receiving member, and is received by the receiving surface 44 a. As shown in fig. 13 (a), the second tooth member 70 is rotatably supported by a fulcrum MS that is movable in the column axial direction X and is formed at a position where the receiving surface 44a on the receiving surface 44a comes into contact with the received portion 71.

The driving portion 72 is a stepped portion provided on the lower surface 73b of the body portion 73, and faces the column axial direction lower side XL. The driving portion 72 is spaced apart from the received portion 71 on the upper side XU in the column axial direction. The driving portion 72 formed by the stepped portion faces an end surface of the moving portion 44 on the upper side XU in the column axial direction X. Upon receiving a secondary collision, the driving portion 72 abuts against the moving portion 44, and presses the moving portion 44 to move toward the column axial direction lower XL.

The tooth forming portion 75 is a plate-like member extending so as to protrude from the lower surface 73b of the body portion 73. The tooth forming portion 75 is disposed on the upper side XU in the column axial direction than the driving portion 72. The pair of side surfaces 75a of the tooth forming portion 75 has a pair of second tooth rows 74L in which a plurality of second teeth 74 are arranged. In fig. 4 and 13 (a) and (b), only the second tooth row 74L of one side surface 75a is shown.

The tips of the second teeth 74 of the pair of second tooth rows 74L face outward in opposite directions. The second teeth 74 of each second tooth row 74L can mesh with the first teeth 62 of the corresponding first tooth row 62L from the tooth trace direction D. As shown in fig. 13 (a), the second tooth member 70 includes a plate-like extension portion 76 that extends from the tooth forming portion 75 to be inserted into the slit 15c of the upper cover 15. When performing the expansion adjustment, the first tooth member 60 and the second tooth member 70 are aligned in the left-right direction Z by the abutment of the extension portion 76 with the inner surface of the slit 15 c. Thus, when the first teeth 62 are engaged with the second teeth 74, the first teeth 62 and the second teeth 74 are easily brought into engagement.

Next, the guide mechanism 80 will be explained. As shown in fig. 4 and fig. 13 (a), the guide mechanism 80 includes a guide shaft 81 and an elongated hole 82. The guide shaft 81 is a through shaft extending in the left-right direction Z. The elongated hole 82 is an insertion hole formed in the main body portion 73 of the second tooth member 70 and through which the guide shaft 81 is inserted. The guide mechanism 80 guides the second tooth member 70 in the direction of engagement and disengagement. The guide shaft 81 functions as a coupling member that couples the second tooth member 70 and the lower sleeve 16. The guide shaft 81 as the coupling member can be broken when a secondary collision occurs. The guide shaft 81 is broken when a secondary collision occurs, and thereby the connection between the second tooth member 70 and the lower sleeve 16 is released.

In a side view (as viewed in the left-right direction Z), the direction in which the elongated hole 82 extends may be a direction along the tooth trace direction D of the first tooth 62 in the tooth lock state (meshing state), or may be a direction inclined toward the column axial upper side XU or the column axial lower side XL with respect to the tooth trace direction D of the first tooth 62. As shown in fig. 10, concave portions 73d are formed in the pair of side surfaces 73c of the main body portion 73 of the second tooth member 70 at the upper side XU in the column axial direction and the upper side YU in the pitching direction. The edge of the upper XU in the column axial direction of the elongated hole 82 is disposed in the recess 73d in approximately half of the upper YU in the pitching direction.

The width of the portion of main body 73 where recess 73d is formed is smaller in the left-right direction Z than the width of the remaining portion of main body 73. This narrows the width of a part of the inner surface of the long hole 82 in the left-right direction Z (the direction in which the long hole 82 penetrates). Fig. 9 is a cross-sectional view IX-IX of fig. 7. Fig. 9 (a) shows the engaged state of the tooth lock mechanism 9. Fig. 9 (b) shows the engagement released state of the tooth lock mechanism 9. Fig. 11 (a) is a cross-sectional view XIa-XIa of fig. 9 (a). Fig. 11 (b) is a cross-sectional view XIb-XIb of fig. 9 (b).

As shown in fig. 10, the inner surface of the elongated hole 82 includes an inner surface 82a of the column axial upper side XU and an inner surface 82b of the column axial lower side XL. The inner surface 82a of the elongated hole 82 on the column axial upper side XU includes: and a second contact portion 302, a first contact portion 301 as a breaking load changing portion. In the engaged state of the tooth lock mechanism 9 shown in fig. 13 (a), as shown in fig. 9 (a) and 11 (a), the first contact portion 301 is in contact with the guide shaft 81. In the engagement released state of the tooth lock mechanism 9 shown in fig. 13 (b), the second contact portion 302 is in contact with the guide shaft 81 as shown in fig. 9 (b) and 11 (b).

As shown in fig. 11 (a) and (b), in the axial direction K of the guide shaft 81, the contact range W1 where the first contact portion 301 contacts the guide shaft 81 is smaller than the contact range W2 where the second contact portion 302 contacts the guide shaft 81 (W1 < W2). Thus, the breaking load of the guide shaft 81 (insertion shaft) at the time of receiving a secondary collision in the engaged state is smaller than the breaking load of the guide shaft 81 at the time of receiving a secondary collision in the disengaged state.

That is, the second contact portion 302, which is in contact with the guide shaft 81 in the contact range W2 substantially equal to the width between the pair of planned fracture portions H in the axial direction K of the guide shaft 81, functions to mainly apply a shearing force to the planned fracture portions H upon receiving a secondary collision. In contrast, the first contact portion 301 having the small contact range W1 functions as a fracture promoting portion that accelerates the fracture of the guide shaft 81 by applying a shearing force to the planned fracture portion H to generate a bending force when a secondary collision occurs.

In other words, the first contact portion 301 and the second contact portion 302 function as a breaking load changing portion that changes the breaking load of the guide shaft 81 so that the breaking load of the guide shaft 81 at the time of a secondary collision in the engaged state is different from the breaking load of the guide shaft 81 at the time of a secondary collision in the disengaged state. Fig. 8 is a sectional view VIII-VIII of fig. 7. As shown in fig. 4 and 7, the guide shaft 81 is supported by a support member 100 supported by the lower sleeve 16. The support member 100 includes a first support member 110 and a second support member 120. The first support member 110 is constituted by the guide restricting member 52 of the impact absorbing mechanism 8. The second support member 120 is supported by the first support member 110 (corresponding to the guide restricting member 52). As shown in fig. 7 and 8, the second support member 120 is disposed between the pair of fastened portions 23.

As shown in fig. 5, the guide regulating member 52 as the first support member 110 includes a fixed portion 53e and an extending portion EZ (see fig. 7). The fixed portion 53e is fixed to the lower sleeve 16 at a position on the column axial direction lower side XL than the pair of fastened portions 23. The extending portion EZ extends from the fixed portion 53e to a position (i.e., the upper end 52a of the guide regulating member 52) disposed between the pair of fastened portions 23. As shown in fig. 12 (a), (b), and (c), the second support member 120 includes: a main body 130, a pair of insertion convex portions 140, a first engaging portion 151, a pair of second engaging portions 152, and a pair of support portions 160. The second support member 120 is integrally formed of a material (e.g., synthetic resin).

As shown in fig. 5, the first engaging portion 151 and the second engaging portion 152 engage with the upper end 52a of the guide restricting member 52, which is the first support member 110, in the column axial direction X. As shown in fig. 12 (a) to (c), the main body 130 includes: a pair of side frames 132 and an upper frame 131 extending in the left-right direction Z. The pair of side frames 132 extend from both ends of the upper frame 131 toward the lower pitch direction YL. The main body 130 is formed in an inverted U shape as a whole. The pair of insertion protrusions 140 extend from the outer side surfaces 132a of the corresponding side frames 132.

The first engagement portion 151 extends from the upper frame 131 to project toward the column shaft lower side XL. The pair of second engagement portions 152 extend from the lower portion (portion on the lower side YL in the pitching direction) of the corresponding insertion convex portion 140 toward the column shaft lower side XL. As shown in fig. 5 and 12 (c), an end surface 130a of the body portion 130 on the column axial direction lower side XL and end surfaces 140a of the pair of insertion convex portions 140 on the column axial direction lower side XL abut on an end surface 52b of the guide restricting member 52 on the column axial direction upper side XU. Thereby, the movement of the second support member 120 in the column axial direction X is restricted.

As shown in fig. 5, the first engagement portion 151 engages with an upper surface 54a (an upper surface of the upper plate 541) of the coupling portion 54 in the pitch direction Y at an upper end 52a of the guide restricting member 52 in the column axial direction X. The pair of second engagement portions 152 engage with inner surfaces 53c, which are lower surfaces of upper ends 53a of the pair of guide regulating plates 53 of the guide regulating member 52 in the column axial direction X in the pitch direction Y. The guide restricting member 52 is sandwiched in the pitch direction Y by the first engaging portion 151 and the second engaging portion 152. Thereby, the movement of the second support member 120 in the pitch direction Y can be restricted.

The first engaging portion 151 and the second engaging portion 152 of the second support member 120 are frictionally engaged with the guide restricting member 52. The second support member 120 is positioned in the left-right direction Z with respect to the guide restricting member 52 by frictional engagement force. As shown in fig. 4, at the lower ends of the pair of fastened portions 23 of the lower sleeve 16 in the column axial direction X, support grooves 23c that open to the column axial direction lower side XL are formed. The supporting groove 23c is open at the outer side surface 23a and the inner side surface 23b of the fastened portion 23. The support groove 23c is disposed higher than the upper surface 16d of the wall portion 16c in the pitch direction Y.

As shown in fig. 5, the pair of insertion projections 140 are inserted into and supported by the support grooves 23c of the corresponding fastened portions 23. Each insertion convex portion 140 is accommodated in the support groove 23c together with the corresponding second engagement portion 152 and the upper end 53a of the corresponding guide restricting plate 53. The inner surface 23d of each support groove 23c supports the corresponding insertion projection 140 slidably in the fastening direction of the pair of fastened parts 23 and in the opposite direction to the fastening direction (direction orthogonal to the plane of the drawing in fig. 5, also the left-right direction Z).

As shown in fig. 12 (a) and (b), the pair of support portions 160 extend from the end surface 132b of the corresponding side frame 132 of the body portion 130 on the upper side XU in the column axial direction. The pair of support portions 160 are plate-shaped arms that face each other with a space therebetween in the left-right direction Z. As shown in fig. 8, the main body portion 73 of the second tooth member 70 is disposed between the pair of support portions 160 of the second support member 120 and between the pair of side frames 132.

As shown in fig. 12 (a), a support hole 163 into which the guide shaft 81 is press-fitted is formed in the pair of support portions 160. As shown in fig. 8, a pair of end portions 81a of the guide shaft 81 in the axial direction are loosely fitted into the loose fitting holes 23e provided in the corresponding fastened portions 23, respectively. That is, the guide shaft 81 is positioned by the second support member 120 supported by the guide restricting member 52 (the first support member 110, see fig. 7). In the telescopic adjustment, the loose fitting hole 23e shown in fig. 8 restricts the amount of movement of the guide shaft 81 by any chance when the guide shaft 81 is displaced.

The pair of support portions 160 includes an outer side surface 162 and a pair of slide guide surfaces 161. The pair of slide guide surfaces 161 are formed by inner side surfaces facing each other. The outer surface 162 faces the inner surface 23b of the corresponding fastened portion 23 with a gap S1 therebetween. The amount of the gap S1 is set so that even if the distance between the pair of fastened portions 23 fastened at the time of locking is reduced, the inner surface 23b of each fastened portion 23 does not interfere with the facing surfaces (the outer surface 132a of the side frame 132 and the outer surface 162 of the support portion 160) of the second support member 120 facing each other. Therefore, when the fastening mechanism 7 is locked, the second support member 120 and the guide shaft 81 supported by the same are not loaded from the fastened portion 23.

The pair of slide guide surfaces 161 face the corresponding side surfaces 73c of the main body portion 73 of the second tooth member 70. The pair of slide guide surfaces 161 regulate the movement of the second tooth member 70 in the axial direction (the left-right direction Z) of the guide shaft 81, and slidably guide the opposed side surfaces 73c of the main body portion 73 of the second tooth member 70 in the direction of engagement and disengagement. The guide shaft 81 is made of resin, and is broken by an impact load received from the second tooth member 70 when a secondary collision occurs, for example, in a state where the first tooth 62 and the second tooth 74 are engaged with each other. Specifically, the guide shaft 81 is broken at two predetermined breaking portions H arranged at positions between the pair of slide guide surfaces 161 and the corresponding side surfaces 73c of the main body portion 73 of the second tooth member 70.

Next, the link mechanism 90 will be explained. As shown in fig. 4, the link mechanism 90 includes a force application member 170 and a driving member 180. As shown in fig. 13 (a), the biasing member 170 is a spring member that rotationally biases the second tooth member 70, which is supported by the fulcrum MS and guided by the guide mechanism 80, toward the meshing side with the first tooth member 60. The biasing member 170 biases the receiving portion 71 of the second tooth member 70 against the receiving surface 44a of the moving portion 44 of the impact absorbing member 40. The driving member 180 drives the second tooth member 70 toward the disengagement side against the urging member 170.

As shown in fig. 4, the driving member 180 includes a cylindrical main body portion 182 and a release protrusion 184. The body 182 has a fitting hole 181 into which the fastening shaft 25 is integrally rotatably inserted. The release projection 184 projects from the outer periphery 183 of the body 182. As shown in fig. 13 (a), a pair of flat portions 25c are formed on the outer periphery of the fastening shaft 25, and the pair of flat portions 25c form a pair of parallel surfaces between each other on the outer periphery of the fastening shaft 25. The inner peripheral surface of the fitting hole 181 has a pair of flat portions that engage with the pair of flat portions 25 c. The fastening shaft 25 and the fitting hole 181 may be spline-fitted.

As shown in fig. 4 and 7, the biasing member 170 includes: a second engaging portion 172, a pair of first engaging portions 171, and a pair of coil portions 173. The pair of first engaging portions 171 engage with the lower case 16. The second engaging portion 172 engages with the second tooth member 70. The pair of coil portions 173 surround the outer periphery 183 of the main body portion 182 of the driving unit 180 at a pair of end portions of the main body portion 182 in the axial direction. The pair of coil portions 173 includes one end 173a on the upper side XU in the column axial direction and the other end 173b on the lower side XL in the column axial direction.

Each first engaging portion 171 extends from one end 173a of the corresponding coil portion 173 in a perpendicular shape (outward in the left-right direction Z), and engages with an engaging recess 23f, which is an engaging portion, of the corresponding fastened portion 23. As shown in fig. 7, the second engaging portion 172 extends perpendicularly from the other ends 173b of the pair of coil portions 173 so as to connect the other ends 173b to each other. As shown in fig. 13 (a), the second engaging portion 172 engages with the upper surface 73a of the main body portion 73 of the second tooth member 70.

The release protrusion 184 engages with an engagement protrusion 77, which is an engagement portion provided in the body portion 73 of the second tooth member 70, as the fastening shaft 25 rotates in the unlocking direction. Thereby, the release protrusion 184 rotationally displaces the second tooth member 70 toward the engagement release side against the biasing member 170. When the operation lever 26 is rotated in the locking direction [ counterclockwise in fig. 13 (b) ], the driving member 180 rotates counterclockwise together with the fastening shaft 25 from the state shown in fig. 13 (b) to the state shown in fig. 13 (a).

Thereby, the release protrusion 184 of the driving member 180 releases the engagement with the engagement protrusion 77 of the second tooth member 70. Therefore, the urging member 170 rotationally drives the second tooth member 70 clockwise about the fulcrum MS, and the second tooth 74 meshes with the first tooth 62 from the tooth trace direction D [ see (a) of fig. 13 ]. Thereby, the telescopic locking by the tooth locking can be realized.

Conversely, when the operating lever 26 is rotated in the unlocking direction [ clockwise in fig. 13 (a) ], the driving member 180 rotates clockwise together with the fastening shaft 25 from the state shown in fig. 13 (a) to the state shown in fig. 13 (b). Thereby, the release protrusion 184 of the driving member 180 pushes up the engagement protrusion 77 of the second tooth member 70. Therefore, the second tooth member 70 is driven to rotate counterclockwise about the fulcrum MS, and the second tooth 74 is separated from the first tooth 62 in the tooth trace direction D, and the engagement is released [ see fig. 13 (b) ]. Thereby, the telescopic lock by the tooth lock is released.

As shown in fig. 4, the steering device 1 includes a first limiting mechanism 210 and a second limiting mechanism 220 that limit a pair of end positions of the movement range of the upper cover 15 during telescopic adjustment. The first restriction mechanism 210 restricts the position of the upper casing 15 in the column axial direction X when the upper casing 15 is at the maximum extension position where it extends the longest from the lower casing 16. The second limiting mechanism 220 limits the position of the upper casing 15 in the tubular column axial direction X when the upper casing 15 is at the most shortened position that is the shortest relative to the lower casing 16.

The first limiting mechanism 210 includes a first stopper 211 and a first engaging portion 212. The first stopper portion 211 is held by the fastened portion 23 of the lower cover 16 corresponding to the other fastening member 30. The first engaging portion 212 is integrally provided on the first tooth member 60, and the first engaging portion 212 engages with the first stopper portion 211 in a state where the upper cover 15 is at the maximum extension position.

The first engaging portion 212 is a cube-shaped block integrally formed to protrude from the surface 60d of the first tooth member 60.

The first stopper portion 211 is inserted and held in the holding hole 23g penetrating the fastened portion 23 corresponding to the other fastening member 30 in the left-right direction Z. A part of the first stopper portion 211 protrudes from the inner side surface 23b of the fastened portion 23 corresponding to the other fastening member 30, and the part of the first stopper portion 211 comes into sliding contact with the surface 60d of the first tooth member 60 at the time of expansion and contraction adjustment. Although not shown, the first stopper portion 211 includes at least a part of a current-carrying member, and is in contact with the inner surface 19b of the side plate 19 so as to be able to carry out current. The first stopper 211 is in electrically contactable contact with the upper jacket 15 via the first tooth member 60. Thereby, the upper case 15 and the lower case 16 can be electrically connected to each other via the first stopper 211 and the first tooth member 60.

In the steering device 1, it is necessary to secure a conductive path in order to electrically connect a horn (not shown) provided in the steering member 10 to the vehicle body 2. However, grease (insulation) for smooth sliding during pitch adjustment and telescopic adjustment is often applied between the upper sleeve 15 and the lower sleeve 16 and between the lower sleeve 16 and the side plate 19. In this case, it is difficult to set a conductive path between these components.

Therefore, in the present embodiment, the conductive member (first stopper 211) is provided to contact the conductive portion (first tooth member 60) on the upper cover 15 and the side plate 19. This ensures a conductive path from the steering member 10 to the vehicle body 2 via the steering shaft 3, the upper sleeve 15, the conductive member (the first stopper 211), and the upper bracket 6 in this order with excellent assembly performance. Since the first stopper 211 is held in the holding hole 23g, space can be saved without increasing the size.

The second limiting mechanism 220 includes a second stopper 221 and a second engaging portion 222. The second stopper 221 is provided on an end surface of the tooth forming portion 75 of the second tooth member 70 on the upper side XU in the column axial direction. The second engaging portion 222 is fixed to the first tooth member 60, and engages with the second stopper portion 221 in a state where the upper cover 15 is at the above-described shortest position. When the upper case 15 attempts to move toward the column axial lower side XL with respect to the lower case 16 upon a secondary collision in the engaged state of the tooth lock mechanism 9, the second tooth member 70 in the engaged state with the first tooth member 60 fixed to the upper case 15 gives an impact force to the guide shaft 81 supported by the second support member 120.

Therefore, the guide shaft 81 is broken at the predetermined breaking portion H at two positions shown in fig. 9 (a) and 11 (a). As the guide shaft 81 breaks, the second tooth member 70 is released from the support by the second support member 120, and as shown in fig. 15, the second tooth member 70 moves together with the upper jacket 15 toward the column axial lower side XL while maintaining the engagement with the first tooth member 60. Thereby, the moving portion 44 of the shock absorbing member 40 is pressed and moved toward the column axial direction lower side XL by the driving portion 72 of the second tooth member 70.

As the moving portion 44 moves, the impact absorbing member 40 deforms so that the length of the first plate portion 41 decreases and the length of the second plate portion 42 increases in the column axial direction X while moving the position of the folded portion 43 toward the column axial direction lower side XL. The energy generated by the secondary collision is absorbed by this deformation. Upon receiving a secondary collision, the guide restricting plate 53 of the guide restricting member 52 not only restricts the floating of the first plate portion 41 but also guides the folding deformation from the first plate portion 41 toward the folded portion 43. When a secondary collision occurs, the guide regulating surface 51 of the surface 60d of the first tooth member 60 regulates bulging of the second plate portion 42 between the folded portion 43 and the moving portion 44 and guides deformation from the folded portion 43 toward the second plate portion 42 so that the second plate portion 42 is approximately parallel to the first plate portion 41. In other words, the deformation movement of the shock absorbing member 40 is guided between the guide restricting plate 53 of the guide restricting member 52 and the guide restricting surface 51 of the first tooth member 60.

The upper plate 541 of the coupling portion 54 of the guide restricting member 52 guides the upper surface 73a of the body portion 73 of the second tooth member 70 toward the column axial direction lower side XL. The guide regulating surface 51 of the first tooth member 60 guides the moving portion 44 of the received portion 71, on which the second tooth member 70 is received, to the column axial direction lower side XL. Thereby, the second tooth member 70 is guided to move toward the column axial lower side XL.

On the other hand, when a secondary collision occurs in the disengaged state of the tooth lock mechanism 9, the upper sleeve 15 moves toward the column axial lower side XL with respect to the lower sleeve 16. When the upper sleeve 15 moves to the shortest position, the second engaging portion 222 provided on the first tooth member 60 that moves integrally with the upper sleeve 15 collides with the second stopper portion 221 of the second tooth member 70 in the disengaged state, and gives an impact force to the guide shaft 81 supported by the second support member 120.

Therefore, the guide shaft 81 is broken at the predetermined breaking portion H at two positions shown in fig. 9 (b) and 11 (b). As the guide shaft 81 breaks, the second tooth member 70 is released from the support by the second support member 120, and moves toward the column axial direction lower side XL together with the upper jacket 15, as shown in fig. 16. Thereby, the moving portion 44 of the shock absorbing member 40 is pushed and moved toward the column axial direction lower side XL by the driving portion 72 of the second tooth member 70. As a result, the impact absorbing member 40 is deformed, and the energy resulting from the secondary collision is absorbed by the deformation.

In the present embodiment, when a secondary collision occurs in the fastened state, the second tooth member 70 in the meshed state breaks the coupling member (the guide shaft 81 as the insertion shaft), and further deforms the shock absorbing member 40 to absorb the shock, as shown in fig. 15. In the released state, when a secondary collision occurs, the driving member (the second engagement portion 222 of the second restriction mechanism 220) that moves integrally with the upper jacket 15 abuts against the second tooth member 70 in the released state of engagement to break the coupling member (the guide shaft 81), and further, as shown in fig. 16, the impact absorbing member 40 is deformed via the second tooth member 70 to absorb the impact. The same impact absorbing member 40 is used to absorb the impact in the fastened state and the unfastened state. That is, with a simple structure, the impact at the time of the secondary collision can be absorbed in both the fastened state and the unfastened state.

The driving member (second engaging portion 222) functions to come into contact with the second stopper portion 221 in the released state to regulate the end position of the telescopic adjustment range. Therefore, the structure can be simplified as compared with a case where a member abutting against the second stopper portion 221 is provided separately from the driving member. In other words, when the upper jacket 15 is at the shortest position that is the shortest relative to the lower jacket 16, the drive member also serves as the second engagement portion 222 of the second regulation mechanism 220 that regulates the position of the upper jacket 15 in the column axial direction X. Therefore, the configuration can be simplified.

By acting on the breaking load changing portions (first contact portion 301, second contact portion 302) provided on the inner surface of the insertion hole (elongated hole 82) of the second tooth member 70 on the upper XU side in the column axial direction, the breaking load of the guide shaft 81 (insertion shaft coupling member) at the time of a secondary collision can be changed between the engaged state (corresponding to the fastened state of the fastening mechanism) and the disengaged state (corresponding to the unfastened state of the fastening mechanism). The breaking load changing portion includes a first contact portion 301 and a second contact portion 302. That is, of the first contact portion 301 which comes into contact with the guide shaft 81 in the engaged state and the second contact portion 302 which comes into contact with the guide shaft 81 in the disengaged state, the contact portion which comes into contact with the guide shaft 81 in the axial direction K has a small contact range, and the guide shaft 81 is easily bent in response to a secondary collision, so that the breaking load of the guide shaft 81 is reduced. This allows the breaking load of the guide shaft 81 at the time of a secondary collision to be changed between the fastened state and the unfastened state.

Specifically, the fracture promoting portion (first contact portion 301) provided on the inner surface 82a of the elongated hole 82 of the second tooth member 70 on the upper side XU in the column axial direction functions, so that the fracture load of the guide shaft 81 (insertion shaft) at the time of receiving the secondary collision in the engaged state (corresponding to the fastened state of the fastening mechanism 7) is smaller than the fracture load of the guide shaft 81 receiving the secondary collision in the disengaged state (corresponding to the unfastened state of the fastening mechanism 7). On the other hand, in the engaged state, when a secondary collision occurs, of the fracture load on the guide shaft 81, a load that generates a sliding friction force when the upper sleeve 15 has a sliding friction with respect to the lower sleeve 16 becomes a disengagement load. Therefore, a difference between the disengaging load in the engaged state (fastened state) and the disengaging load in the disengaged state (unfastened state) can be suppressed.

At an inner surface 82a of the elongated hole 82 of the second tooth member 70 on the column axial direction upper side XU, a contact range W1 of the first contact portion 301 (fracture promoting portion) that comes into contact with the guide shaft 81 in the engaged state is smaller than a contact range W2 of the second contact portion 302 that comes into contact with the guide shaft 81 in the disengaged state (W1 < W2). This facilitates the bending of the guide shaft 81 when a secondary collision is received in the engaged state, and the breaking load of the guide shaft 81 when a secondary collision is received in the engaged state is smaller than the breaking load of the guide shaft 81 when a secondary collision is received in the disengaged state.

Further, as a modification of the present embodiment, although not shown, there may be mentioned an example in which the contact range W2 of the second contact portion 302 is smaller than the contact range W1 of the first contact portion 301, and the breaking load of the guide shaft 81 at the time of receiving a secondary collision in the disengaged state (corresponding to the non-fastened state of the fastening mechanism 7) is smaller than the breaking load of the guide shaft 81 (insertion shaft) at the time of receiving a secondary collision in the engaged state (corresponding to the fastened state of the fastening mechanism 7). The contact portion on the side where the contact range is small (either one of the first contact portion 301 and the second contact portion 302) may be formed by a top portion of a protrusion provided on the inner surface of the long hole 82 (insertion hole).

As shown in fig. 13 (a), the second tooth member 70 is rotatably supported by a fulcrum MS that is movable in the column axial direction X and is formed at a position where the receiving surface 44a of the receiving member (the shock absorbing member 40) and the received portion 71 of the second tooth member 70 contact each other. Therefore, at the time of assembly, the movable fulcrum MS can be formed by the operation of placing the receiving portion 71 of the second tooth member 70 on the receiving surface 44a of the receiving member (the impact absorbing member 40). Therefore, as in the conventional art, a troublesome work of inserting the support shaft as the rotation center of the gear member into the support hole is not required, and the assembling property is improved.

The receiving member doubles as the impact absorbing member 40, and thus the structure can be simplified. As shown in fig. 8, the guide shaft 81, which is broken when the secondary collision is received, is supported by the pair of support portions 160 of the second support member 120 in a state of being fastened by the fastening mechanism 7 and being separated from the pair of fastened portions 23 displaced in the left-right direction Z. The pair of support portions 160 are provided on the second support member 120 supported by the extended portion EZ extending from the fixed portion 53e fixed to the lower case 16 at the column axial direction lower side XL than the pair of fastened portions 23 as shown in fig. 5 to between the pair of fastened portions 23 as shown in fig. 7.

Therefore, at the time of a secondary collision, the guide shaft 81 is broken under a stable breaking load due to the load of the pair of support portions 160 that is never affected by the difference in displacement of the pair of fastened portions 23. Therefore, stable impact absorption characteristics can be obtained when a secondary collision occurs. The pair of support portions 160 includes a pair of slide guide surfaces 161 that slidably guide the pair of side surfaces 73c of the main body portion 73 of the second tooth member 70. The movement of the second tooth member 70 in the axial direction of the guide shaft 81 is restricted by the slide guide surfaces 161 of the pair of support portions 160 upon receiving a secondary collision, and therefore the guide shaft 81 breaks under a more stable breaking load upon receiving a secondary collision. This makes it possible to obtain stable impact absorption characteristics when a secondary collision occurs. Fig. 17 (a) and (b) are sectional views of the structure around the tooth lock mechanism of the steering device according to the second embodiment of the present invention, in which fig. 17 (a) shows a locked state (engaged state), and fig. 17 (b) shows an unlocked state (disengaged state).

As shown in fig. 17 (a) and (b), the second embodiment is mainly different from the first embodiment as follows. That is, the second limiting mechanism 720 for limiting the end position (the most shortened position) of the expansion/contraction adjustment range of the upper cover 15 is constituted by the second stopper 721 and the second engaging portion 722. The second stopper 721 is provided on the driving member 180P for releasing the engagement of the link mechanism 90P. The second engagement portion 722 is a driving member that drives the impact absorbing member 40 when a secondary collision occurs.

The second stopper 721 has a stopper surface 723. The second engaging portion 722 is integrally fixed to the first tooth member 60. The second engaging portion 722 has an engaging surface 724 at an end of the column axial lower side XL, which engages with a stopper surface 723 of the second stopper 721. The engaging surface 724 of the second engaging portion 722 is formed as an inclined surface inclined with respect to the column axial direction X. As shown in fig. 17 (b), in the disengaged state, the stopper surface 723 of the second stopper 721 is inclined at the same inclination angle as the engaging surface 724 in the direction opposite to the column axial direction X with respect to the engaging surface 724.

As shown in fig. 17 (b), the second engaging portion 722 as the driving member abuts against the second stopper portion 721 in the disengaged state, thereby limiting the end position (the most shortened position) of the expansion/contraction adjustment range of the upper cover 15. At this time, the normal lines of the stopper surface 723 and the engagement surface 724 face the center of the fastening shaft 25 (i.e., the rotation center of the driving member 180P).

Therefore, when the end position (the most shortened position) of the expansion/contraction adjustment range is limited, the driving member 180P for disengagement is not subjected to a moment from the second engagement portion 722 (the driving member) and the posture of the driving member 180P is not changed. When the tip end position (most shortened position) is regulated, the posture of the drive member 180P is not changed, and therefore the posture of the second tooth member 70 is not changed, and therefore, no load is applied to the guide shaft 81 by an impact at the time of regulation. Further, the posture of the operation lever 26 is not changed by the impact at the time of the regulation.

The driving member 180P is fitted to the fastening shaft 25 so as to be rotatable integrally therewith. The second stopper 721 is formed by a part of the projection 185 of the driving member 180P disposed on the opposite side of the tightening shaft 25 from the release projection 184. Specifically, the protrusion 185 includes the base 186, the breaking portion 187, and the second stopper portion 721 described above. The base 186 is integrally coupled to the outer periphery 183 of the body 182. The breaking portion 187 is disposed between the base 186 and the second stopper 721. That is, the second stopper 721 is coupled to the base 186 through the breaking portion 187.

When a secondary collision is received in the released state (released state), the breaking portion 187 is broken by the second engaging portion 722 as the driving member coming into contact with the second stopper portion 721. For example, as shown in fig. 18, which is a schematic cross-sectional view of the periphery of the protrusion 185, the breaking portion 187 is formed by the bottom of a groove 188 extending in the column axial direction X in a state where the engagement of the second tooth member 70 by the drive member 180P is released. The second stopper 721 is connected to the base 186 at the driving member 180P by the bottom (the breaking portion 187) of the groove 188.

As shown in fig. 17 (a), the second stopper portion 721 avoids the movement path of the second engagement portion 722 serving as the driving member when the secondary collision is received in the engaged state. In the present embodiment, as shown in fig. 17 (a), the second stopper portion 721 that restricts the end position of the expansion/contraction adjustment range in the engagement released state avoids the movement path of the second engagement portion 722 (driving member) when receiving a secondary collision in the engaged state (fastened state). Therefore, in the fastened state, when a secondary collision is received, the second engaging portion 222 (driving member) does not abut against the second stopper portion 721. Therefore, in the fastened state, when a secondary collision is received, the same impact absorption characteristic can be obtained regardless of the telescopic adjustment position.

As shown in fig. 17 (b), when a secondary collision is received in the unfastened state, the second engaging portion 722 abuts against the second stopper portion 721, and the breaking portion 187 is broken to generate an impact absorbing load. Therefore, by setting the breaking load of the breaking portion 187, the detachment load at the time of receiving the secondary collision in the unfastened state can be set as desired. Since the second stopper portion 721 is formed to be detached along with the fracture of the fracture portion 187, the second engagement portion 722 (driving member) can be allowed to move toward the second tooth member 70 side, and therefore the impact absorbing member 40 can be made to contribute to the impact absorption at the time of the secondary collision.

The breaking portion 187 may be a weak portion thinner than the adjacent portion. Although not shown, the second engaging portion 722 may be integrally formed with the first tooth member 60 or the upper cover 15 by, for example, forming a tongue piece and pushing up the tongue piece. Fig. 19 (a), (b), and (c) are cross-sectional views of the structure of the periphery of the guide shaft 81 that breaks when a secondary collision occurs in the third, fourth, and fifth embodiments of the present invention, respectively.

In the third embodiment shown in fig. 19 (a), a protrusion 400 serving as a fracture promoting portion (fracture load changing portion) having a top portion 401 abutting on the guide shaft 81 is provided on an inner surface 82a of the elongated hole 82 (insertion hole) on the upper XU in the column axial direction. The top 401 of the projection 400 is disposed at the center of the inner surface 82a in the axial direction K of the guide shaft 81. The top 401 of the protrusion 400 may function as a contact portion having a narrow contact range between the first contact portion 301 and the second contact portion 302 in the first to second embodiments. In the third embodiment, when a secondary collision is received in the engaged state, the top portion 401 of the projection 400 as the fracture promoting portion comes into contact with the guide shaft 81 to accelerate the occurrence of stress concentration, thereby accelerating the cutting (fracture) by shearing.

In the fourth embodiment shown in fig. 19 (b), a pair of protrusions 500 serving as fracture promoting portions (fracture load changing portions) are provided on the inner surface 82a of the elongated hole 82 (insertion hole) on the upper XU in the column axial direction, and are spaced apart in the axial direction K of the guide shaft 81. The top portions 501 of the pair of protrusions 500 may function as contact portions having a narrow contact range between the first contact portion 301 and the second contact portion 302, as in the first to second embodiments. In the fourth embodiment, when a secondary collision is received in the engaged state, the top portions 501 of the pair of projections 500 serving as the fracture promoting portions come into contact with the guide shaft 81 to accelerate stress concentration, thereby accelerating the cutting (fracture) by shearing.

In the fifth embodiment shown in fig. 19 (c), a notch 600 serving as a fracture promoting portion (fracture load changing portion) is formed in the guide shaft 81. The notch 600 is formed in a V-shaped cross section, for example, in a part or all of the outer periphery of the guide shaft 81 in the circumferential direction. The notch 600 is disposed at the center between the pair of support portions 160 in the axial direction K of the guide shaft 81. The notch 600 may be disposed on the opposite side of the outer periphery of the guide shaft 81 as the first to second embodiments from the position where it is opposed to the contact portion (in the illustrated example, the first contact portion 301) having a narrow contact range of the first contact portion 301 and the second contact portion 302. In the fifth embodiment, when a secondary collision is received in the engaged state, stress concentration of the guide shaft 81 is accelerated by the notch 600 serving as a fracture promoting portion, and thus the cutting (fracture) by shearing is accelerated.

In the structures (a) and (b) of fig. 19, the notch of fig. 19 (c) may be provided. Fig. 20 (a) and (b) are schematic side views of a tooth lock structure of a steering device according to a sixth embodiment of the present invention, in which (a) shows an engaged state (locked state) and (b) shows an disengaged state (unlocked state).

As shown in fig. 20 (a) and (b), the second tooth member 70Q has only the second tooth 74, the engaging projection 77, and the insertion hole 82Q formed of, for example, a circular hole. An insertion shaft 81Q supported by the lower case via the support mechanism is inserted into the insertion hole 82Q. The second tooth member 70Q is supported to be rotatable about the insertion shaft 81Q. The second tooth member 70Q is changed between the engaged state and the disengaged state in accordance with the rotation about the insertion shaft 81Q. The insertion shaft 81Q is made of resin and breaks when subjected to a secondary collision.

A projection 800 is formed to project from the inner surface 82Qa of the insertion hole 82Q, and the projection 800 serves as a breaking load changing portion for cutting (breaking) the insertion shaft 81Q by shearing when a secondary collision occurs. Upon receiving the secondary collision, the top 801 of the projection 800 abuts against the insertion shaft 81Q, and the insertion shaft 81Q is cut (broken) by shearing. The projection 800 is also used for shearing in the engaged state shown in fig. 20 (a) and the disengaged state shown in fig. 20 (b). For example, in any one of the engaged state and the disengaged state [ the engaged state of fig. 20 (a) in the present embodiment ], the projection 800 is disposed at a position substantially facing the center C1 of the insertion shaft 81Q in the column axial direction X. In the other of the engaged state and the disengaged state [ in the present embodiment, the disengaged state of fig. 20 (b) ], the projection 800 is disposed at a position facing the center C1 of the insertion shaft 81Q in a direction inclined with respect to the column axial direction X.

Therefore, when a secondary collision occurs, the angle θ 1 formed by the shearing direction U1 in which the projection 800 shears the insertion shaft 81Q in the engaged state shown in fig. 20 (c) and the column axial direction X is different from the angle θ 2 formed by the shearing direction U2 in which the projection 800 shears the insertion shaft 81Q in the disengaged state shown in fig. 20 (d) and the column axial direction X. Either one of the angle θ 1 and the angle θ 2 may also be zero.

In the present embodiment, when a secondary collision occurs, the shearing directions U1, U2 in which the projection 800 shears the insertion shaft 81Q are different between the engaged state (fastened state) and the disengaged state (unfastened state), and therefore the breaking load of the insertion shaft 81Q is different. This makes it possible to change the breaking load of the insertion shaft 81Q when a secondary collision is applied in the fastened state and the unfastened state. The present invention is not limited to the above embodiments, and for example, one second tooth 74 of the second tooth member 70 may be provided.

The fracture promoting portion of the fracture load changing portion of the present invention may function in any state of the engaged state and the disengaged state. In other words, it is sufficient if the fracture promoting portion is provided in order to set the fracture load in the engaged state and the disengaged state according to design. The loose fitting hole 23e of the pair of fastened parts 23 in fig. 9 may be eliminated. In this case, although not shown, each end 81a of the guide shaft 81 and the corresponding inner surface 23b of the pair of fastened portions 23 face each other with a predetermined interval in the axial direction K of the guide shaft 81.

The present invention is not limited to a manual type steering device that assists the steering operation of the steering member 10, and can be applied to an electric power steering device that assists the steering operation of the steering member 10 by applying power of an electric motor to the steering shaft 3. The present invention can be variously modified within the scope of the claims.

This application claims priority from Japanese patent application No. 2016-133535, filed on 5/2016 and Japanese patent application No. 2016-225355, filed on 18/2016, and is incorporated herein by reference in its entirety, including the specification, drawings and abstract of the specification.

Claims (8)

1. A steering device is provided with:

a steering shaft that is capable of extending and retracting in the axial direction of the column;

a column jacket including a lower jacket and an upper jacket fitted to the lower jacket, rotatably supporting the steering shaft, and being extendable and retractable in the column axial direction during telescopic adjustment;

a fastening mechanism that fastens and holds the upper case by the lower case;

an impact absorbing member supported by the lower case and absorbing an impact by deforming;

a first tooth member that moves in the tubular string axial direction integrally with the upper sleeve;

a second tooth member that is brought into an engagement state with the first tooth member when the fastening mechanism is used for fastening, and is brought into an engagement release state in which the engagement is released when the fastening mechanism is used for releasing the fastening;

a connecting member that connects the second tooth member and the lower cover and is breakable when a secondary collision occurs; and

a drive member that is movable in the column axial direction integrally with the upper case, and that, when a secondary collision is received in a released state of the fastening mechanism, contacts the second tooth member in the released state of engagement to break the connecting member and deform the impact absorbing member via the second tooth member, characterized in that the drive member is configured to be able to move in the column axial direction integrally with the upper case,

and, when a secondary collision is received in a fastened state of the fastening mechanism, the second tooth member in the engaged state breaks the coupling member and deforms the impact absorbing member.

2. The steering device according to claim 1, further comprising:

a stopper provided to the lower case or a member supported by the lower case,

the drive member abuts against the stopper portion in the disengaged state to regulate the end position of the telescopic adjustment range of the upper sleeve.

3. The steering device according to claim 2,

the stopper portion is configured to avoid a moving path of the driving member when a secondary collision is received in the engaged state.

4. The steering device according to claim 2,

the lower case or the member supported by the lower case is connected to the stopper portion via a fracture portion which is fractured by abutment of the driving member and the stopper portion when a secondary collision is applied in the engagement released state,

the drive member is allowed to move toward the second tooth member side by the drop-out of the stopper portion due to the fracture of the fracture portion.

5. The steering device according to claim 3,

the lower case or the member supported by the lower case is connected to the stopper portion via a fracture portion which is fractured by abutment of the driving member and the stopper portion when a secondary collision is applied in the engagement released state,

the drive member is allowed to move toward the second tooth member side by the drop-out of the stopper portion due to the fracture of the fracture portion.

6. The steering device according to any one of claims 1 to 5,

an insertion hole is formed in the second tooth member,

the coupling member includes an insertion shaft extending in a direction orthogonal to the column axial direction, inserted through the insertion hole, and slid relative to the insertion hole in accordance with rotational displacement of the second tooth member,

an inner surface of the insertion hole on an upper side in a column axial direction includes a breaking load changing portion that changes a breaking load of the insertion shaft so that the breaking load of the insertion shaft when the insertion shaft receives a secondary collision in the engaged state is different from the breaking load of the insertion shaft when the insertion shaft receives a secondary collision in the disengaged state.

7. The steering device according to claim 6,

the breaking load changing unit includes: a first contact portion that comes into contact with the insertion shaft when a secondary collision is received in the engaged state, and a second contact portion that comes into contact with the insertion shaft when a secondary collision is received in the disengaged state,

the contact range in which the first contact portion makes contact with the insertion shaft in the axial direction of the insertion shaft is different from the contact range in which the second contact portion makes contact with the insertion shaft in the axial direction of the insertion shaft.

8. The steering device according to claim 6,

the breaking load changing portion includes a projection which shears the insertion shaft when a secondary collision occurs and which is usable both in the engaged state and in the disengaged state,

the angle formed by the shearing direction in which the projection shears the insertion shaft in the engaged state and the column axial direction is different from the angle formed by the shearing direction in which the projection shears the insertion shaft in the disengaged state and the column axial direction.

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