POSITION ADJUSTABLE STEERING DEVICE
When clamped side plates of an upper column bracket (movable bracket) are fastened via clamping side plates of an upper fixed bracket by a fastening shaft in response to a rotating operation of an operating lever, the brackets are locked with each other. A pressing mechanism that includes a pressing member moves in the axial direction of the fastening shaft in accordance with fastening by the fastening shaft, and presses a lower tube (inner tube) through an insertion hole formed in an upper tube (outer tube). The entirety of the axial force of the fastening shaft is used as a retaining force for retaining the posture of a steering column.
This application is a divisional application of U.S. patent application Ser. No. 13/713,440, filed Dec. 13, 2012, which claims priority to Japanese Patent Applications No. 2011-279883 filed on Dec. 21, 2011 and No. 2011-279884 filed on Dec. 21, 2011. The disclosures of the above applications are incorporated herein by reference in its entirety.
BACKGROUND OF THE INVENTION1. Field of the Invention
The invention relates to a position adjustable steering device.
2. Description of Related Art
There is a steering column device in which a vehicle body attachment bracket is fastened to reduce the diameter of an outer column (outer tube) with an axial slit via a pair of clamp members, thereby clamping an inner column (inner tube) to the outer column (see, for example, Japanese Patent No. 4609203, Japanese Patent Application Publication No. 2010-105662 (JP 2010-105662 A), and Japanese Patent Application Publication No. 2010-189003 (JP 2010-189003 A)).
There is a steering column device in which a fixed side wall of a vehicle body fixed bracket (fixed bracket) is arranged at one side of a tubular steering column, and a tension plate, which serves as an elastic member and of which one end is fixed to a top plate of the fixed bracket, is arranged at the other side of the steering column (see, for example, Japanese Patent Application Publication No. 2009-286341 (JP 2009-286341 A)).
In JP 2009-286341 A, a side plate of a fastening bracket fixed to an outer column (outer tube) of the steering column is fastened toward the fixed side wall by a fastening member. In this way, the brackets are locked. In addition, there is provided a coupling member that couples the tension plate to an inner column (inner tube). The coupling member passes through the outer column and the inner column, and a rib portion formed at one end of the coupling member is located inside the inner column. When the brackets are fastened by the fastening member, the rib portion of the coupling member pulled by the tension plate is pressed against the inner periphery of the inner column. As a result, the inner column is pressed against the outer column.
There is a steering device that prevents displacement in a telescopic direction by pressing the outer periphery of an inner column. The outer periphery of the inner column is pressed by pressing a column retaining member with a slit, using a plate portion of a tilt bracket (fixed bracket) fixed to a vehicle body, thereby reducing the inside diameter of the column retaining member (see, for example, WO05/037627).
There is a vehicle steering device in which a lock plate fixed to an upper bracket (fixed bracket) and a lock plate fixed to a distance bracket (movable bracket), to which a column jacket is fixed, respectively have teeth that mesh with each other, and axial movement of the column jacket is prevented by the meshing of the teeth (see, for example, Japanese Patent Application Publication No. 7-117685 (JP 7-117685 A).
In Japanese Patent No. 4609203, JP 2010-105662 A and JP 2010-189003 A, the inner column is retained by reducing the diameter of the outer column (outer tube). Therefore, there is a possibility that sufficient retaining force will not be obtained due to the influence of, for example, variations in dimensional accuracy.
In JP 2009-286341 A, the coupling member passes through the outer column and the inner column, and the rib portion formed at one end of the coupling member is located inside the inner column. Therefore, it is difficult to assemble the steering column device.
In WO05/037627, the inner column is retained by reducing the diameter of the column retaining member. Therefore, there is a possibility that sufficient retaining force will not be obtained due to the influence of, for example, variations in dimensional accuracy.
In JP 7-117685 A, the teeth of the both lock plates may be fastened to each other to be locked in a state where top portions of the teeth face each other. In this case, when the both lock plates are displaced by some impact and placed in a state where the teeth of one of the lock plates face tooth grooves of the other lock plate, the axial force of a fastening shaft is reduced, and the retainment of the posture of the steering column may be insufficient.
SUMMARY OF THE INVENTIONIt is an object of the invention to provide a position adjustable steering device that reliably retains the posture of a steering column and that is easily assembled.
An aspect of the invention relates to a position adjustable steering device, including: a steering column that includes an outer tube and an inner tube that are fitted to each other so as to be relatively slidable in an axial direction of the steering column to make telescopic adjustment, and that support a steering shaft such that the steering shaft is rotatable; a fixed bracket that has a pair of clamping side plates, and that is fixed to a vehicle body; a movable bracket that has a pair of clamped side plates arranged along inner side faces of the respective clamping side plates, and that is fixed to the outer tube; a fastening mechanism that includes a fastening shaft that passes through the clamping side plates and the clamped side plates, and that achieves telescopic lock by fastening the clamped side plates with use of the fastening shaft via the clamping side plates in accordance with a rotating operation of an operating lever; an insertion hole that is formed in the outer tube; and a pressing mechanism that moves in an axial direction of the fastening shaft in accordance with fastening by the fastening shaft, and that has a pressing member that presses the inner tube through the insertion hole.
The foregoing and further objects, features and advantages of the invention will become apparent from the following description of preferred embodiments with reference to the accompanying drawings, wherein like numerals are used to represent like elements and wherein:
Hereinafter, embodiment of the invention will be described with reference to the accompanying drawings.
The steering member 2 and the steering mechanism 3 are mechanically coupled to each other via a steering shaft 4, an intermediate shaft 5, and the like. The rotation of the steering member 2 is transmitted to the steering mechanism 3 via the steering shaft 4, the intermediate shaft 5, and the like. The rotation transmitted to the steering mechanism 3 is converted to an axial movement of a rack shaft (not shown). In this way, the steered wheels are steered.
The steering shaft 4 includes a tubular upper shaft 6 and a tubular lower shaft 7. The upper shaft 6 and the lower shaft 7 are relatively slidably fitted to each other through, for example, spline fitting or serration fitting. The steering member 2 is coupled to one end of the upper shaft 6. The steering shaft 4 is telescopic in its axial direction X1. The steering shaft 4 is passed through a tubular steering column 8, and is rotatably supported by the steering column 8 via a plurality of bearings 9, 10.
The steering column 8 includes an upper tube 11 and a lower tube 12. The upper tube 11 is an outer tube. The lower tube 12 is an inner tube. The upper tube 11 and the lower tube 12 are fitted to each other so as to be relatively slidable in the axial direction. Thus, the steering column 8 is telescopic in the axial direction, and telescopic adjustment (described later) is allowed. The upper tube 11 supports the upper shaft 6 via the bearing 9 such that the upper shaft 6 is rotatable. The upper tube 11 is coupled to the upper shaft 6 via the bearing 9 so as to be movable together with the upper shaft 6 in the axial direction X1 of the steering shaft 4.
A lower column bracket 13 is fixed to the outer periphery of the lower tube 12. The lower column bracket 13 is pivotably supported by a lower fixed bracket 15 via a tilt central shaft 16. The lower fixed bracket 15 is fixed to a vehicle body 14. The steering column 8 and the steering shaft 4 are pivotable about the tilt central shaft 16. By causing the steering shaft 4 and the steering column 8 to pivot about the tilt central shaft 16, it is possible to adjust the position of the steering member 2 in the height direction (so-called tilt adjustment). In addition, by extending or contracting the steering shaft 4 and the steering column 8 in the axial direction X1, it is possible to adjust the position of the steering member 2 in the height direction and the position of the steering member 2 in the axial direction (so-called telescopic adjustment).
The position adjustable steering device 1 includes a fastening mechanism 17 used to achieve tilt lock and telescopic lock to fix the position of the steering member 2 of which the height has been adjusted. Specifically, an upper column bracket 18, which may function as a movable bracket, is fixed to the upper tube 11 (outer tube). The upper column bracket 18 is coupled to an upper fixed bracket 19, which may function as a fixed bracket and which is fixed to the vehicle body 14 by the fastening mechanism 17. Thus, tilt lock and telescopic lock are achieved. As a result, the position of the steering column 8 is fixed with respect to the vehicle body 14, and therefore the position of the steering member 2 is fixed.
As shown in
In accordance with the relative rotation between the cam 23 and the cam follower 24, the cam 23 moves the cam follower 24 in an axial direction Y1 of the fastening shaft 20. The cam 23 performs the function of pressing the clamping side plate 29 (30) of the upper fixed bracket 19 against the clamped side plate 26 (50) of the upper column bracket 18. Thus, the brackets 18, 19 are locked, and tilt lock and telescopic lock are achieved.
The upper column bracket 18, which may function as a movable bracket, is a groove-shaped member that opens upward. The upper column bracket 18 includes the clamped side plates 26, 50 and a coupling plate 28. A first end portion 261 of the clamped side plate 26 is fixed to the outer periphery of the upper tube 11. Referring back to
As shown in
The clamped side plates 26, 50 of the upper column bracket 18 are arranged between the clamping side plates 29, 30 of the upper fixed bracket 19. The upper fixed bracket 19 is fixed to the vehicle body 14 via a pair of mounting members 33 coupled to the mounting stay 32. The mounting members 33 each are coupled to the mounting stay 32 by synthetic resin pins 34 that pass through the mounting stay 32 in the up-down direction. The synthetic resin pins 34 may break. The mounting members 33 are fixed to the vehicle body 14 with fixing bolts 35.
Outer side faces of the clamped side plates 26, 50 of the upper column bracket 18 are arranged along inner side faces 29a, 30a of the clamping side plates 29, 30 of the upper fixed bracket 19, respectively. The transversely long holes 36 for telescopic adjustment are formed in the clamped side plates 26, 50 of the upper column bracket 18. The transversely long holes 36 extend in a direction perpendicular to the sheet on which
The fastening mechanism 17 includes the fastening shaft 20, a nut 38, the cam 23 and the cam follower 24. The fastening shaft 20 is passed through the vertically long holes 37 of the clamping side plates 29, 30 of the upper fixed bracket 19 and the transversely long holes 36 of the clamped side plates 26, 50 of the upper column bracket 18. The nut 38 is screwed to a threaded portion formed at one end portion of the fastening shaft 20. The cam 23 and the cam follower 24 are fitted to an outer peripheral portion near the other end portion of the fastening shaft 20. The cam 23 and the cam follower 24 constitute the cam mechanism 22.
A head 201 is formed at the other end portion of the fastening shaft 20. The head 201 of the fastening shaft 20 and the cam 23 are coupled to the operating lever 21 so as to be rotatable together with the operating lever 21. The cam follower 24 has a first portion 241 and a second portion 242. The first portion 241 of the cam follower 24 is arranged along an outer side face 29b of the clamping side plate 29 of the upper fixed bracket 19. The second portion 242 of the cam follower 24 is fitted into the vertically long hole 37 of the clamping side plate 29 of the upper fixed bracket 19 and the transversely long hole 36 of the clamped side plate 26 of the upper column bracket 18 so as to be movable in the directions in which the long holes 37, 36 extend. By forming a width across flat, or the like, at a portion at which the second portion 242 is fitted in the vertically long hole 37 of the clamping side plate 29, the rotation of the second portion 242 is restricted by the vertically long hole 37.
A first intervening member 41 and a second intervening member 42 are interposed between the nut 38 screwed to one end portion of the fastening shaft 20 and the clamping side plate 30 of the upper fixed bracket 19. The first intervening member 41 has a first portion 412 and a second portion 411. The first portion 412 of the first intervening member 41 is arranged along the outer side face 30b of the clamping side plate 30 of the upper fixed bracket 19.
The second portion 411 of the first intervening member 41 is fitted in the vertically long hole 37 of the clamping side plate 30 of the upper fixed bracket 19 and the transversely long hole 36 of the clamped side plate 50 of the upper column bracket 18 so as to be movable in the directions in which the long holes 37, 36 extend. By forming a width across flat, or the like, at a portion at which the second portion 411 is fitted in the vertically long hole 37 of the clamping side plate 30, the rotation of the second portion 411 is restricted by the vertically long hole 37.
The second intervening member 42 includes a thrust washer 43 and a thrust needle roller bearing 44. The thrust washer 43 is interposed between the first portion 412 of the first intervening member 41 and the nut 38. The needle roller bearing 44 is interposed between the thrust washer 43 and the first portion 412 of the first intervening member 41. Due to the function of the second intervening member 42 that includes the needle roller bearing 44, the nut 38 is able to smoothly rotate together with the fastening shaft 20.
A feature of the present embodiment is that a pressing mechanism 60 is provided. The pressing mechanism 60 presses an outer face 12b of one side portion 12a of the lower tube 12 (inner tube) in a direction parallel to the fastening shaft 20 through an insertion hole 11b of one side portion 11a of the upper tube 11 (outer tube) when the pressing mechanism 60 is pressed by the clamping side plate 30 at the time of fastening by the fastening mechanism 17. As shown in
The auxiliary movable bracket 61 has a pressed side plate 63 and a pair of coupling portions 66, 67. The pressed side plate 63 is pressed by the inner side face 30a of the clamping side plate 30 in accordance with fastening by the fastening mechanism 17. The coupling portions 66, 67 couple end portions 64, 65 of the pressed side plate 63 to the outer tube 11, respectively. Each of the coupling portions 66, 67 has elastically deformable bending portions 71 to 74 (see
As shown in
When the pressed side plate 63 is pressed by the inner side face 30a of the clamping side plate 30 in accordance with fastening by the fastening mechanism 17, the bending portions 71 to 74 bend, the coupling portions 66, 67 are deflected, and parallel displacement of the pressed side plate 63 occurs, as shown in
According to the present embodiment, when the clamped side plates 26, 50 of the upper column bracket 18 (movable bracket) are fastened via the clamping side plates 29, 30 of the upper fixed bracket 19 by the fastening shaft 20 in response to a rotating operation of the operating lever 21, both of the brackets 18, 19 are locked with each other. In addition, the pressing mechanism 60 pressed by the clamping side plate 30 of the upper fixed bracket 19 presses the outer face 12b of the one side portion 12a of the lower tube 12 (inner tube) through the insertion hole 11b of the one side portion 11a of the upper tube 11 (outer tube), as shown in
It is possible to use the entirety of the axial force of the fastening shaft 20 as a retaining force for retaining the posture of the steering column 8. Therefore, it is possible to increase the retaining force even when the operating force of the operating lever 21 is substantially the same as that in related art. Consequently, in the event of a secondary collision of a vehicle, it is possible to suppress changes in the posture of the steering column 8 before the tubes 11, 12 contract. Accordingly, at the time of absorbing a shock, it is possible to perform a desired shock absorbing function by appropriately contracting the tubes 11, 12.
Furthermore, because the pressing mechanism 60 is configured such that the lower tube 12 (inner tube) is pressed from the outer side, the position adjustable steering device 1 is easier to assemble than a position adjustable steering device that is configured such that part of the pressing member is arranged inside the inner tube as described in JP 2009-286341 A. The cross section of the lower tube 12 in which the outer face 12b of the one side portion 12a is pressed by the pressing mechanism 60 elastically deforms into an oblong elliptical shape as shown in
In accordance with fastening by the fastening mechanism 17, the auxiliary movable bracket 61 provided so as to protrude from the outer face 11c of the one side portion 11a of the upper tube 11 elastically deforms by being pressed by the clamping side plate 30. As a result, the pressing member 62 fixed to the auxiliary movable bracket 61 presses the outer face 12b of the one side portion 12a of the lower tube 12 through the insertion hole 11b of the upper tube 11. Because the pressing member 62 is fixed to the auxiliary movable bracket 61, it is possible to stably press the lower tube 12.
The pressed side plate 63 of the auxiliary movable bracket 61 is in surface contact with the inner side face 30a of the clamping side plate 30, and receives a fastening force of the fastening mechanism 17. Thus, it is possible to increase the coupling force for coupling the upper fixed bracket 19 to the upper column bracket 18 (movable bracket) and the auxiliary movable bracket 61 to each other. The pressed side plate 63 of the auxiliary movable bracket 61 is supported at both ends by the end portions 64 and 65, and the pressing member 62 is fixed to the pressed side plate 63, at a position between the end portions 64, 65. As a result, the pressing member 62 is stably supported. In addition, the bending portions 71 to 74 of each of the coupling portions 66, 67 adjacent to the end portions 64, 65 of the pressed side plate 63 elastically deform. Thus, it is possible to appropriately displace the pressing member 62, which is fixed to the pressed side plate 63 at a position between the end portions 64 and 65, in a direction parallel to the fastening shaft 20.
Each of the coupling portions 66, 67 has a plurality of (four, in the present embodiment) bending portions 71 to 74. With this configuration, it is possible to ensure a sufficient deflection amount even in the compact pressing mechanism 60. Therefore, it is possible to reliably press the lower tube 12 via the pressing member 62. The clamped side plate 50 that faces the clamping side plate 30 has the vertical plate portions 54, 55 that are apart from each other in the longitudinal direction of the steering column 8 (the axial direction X1 of the steering shaft 4), and the auxiliary movable bracket 61 is arranged between the vertical plate portions 54, 55. Therefore, it is possible to achieve size reduction.
At least part of the location of the fastening shaft 20 overlaps with the location of the pressing member 62 in the longitudinal direction of the steering column 8 (the axial direction X1 of the steering shaft 4). Thus, the fastening force of the fastening shaft 20 is efficiently converted into the pressing force of the pressing member 62. In this way, it is possible to increase the coupling force for coupling the tubes 11, 12 to each other at the time of fastening by the fastening mechanism 17. Note that the invention is not limited to the above embodiment. At least one bending portion should be formed in each of the coupling portions 66, 67 of the auxiliary movable bracket 61 of the pressing mechanism 60. In the above-described embodiment, the nut 38, the fastening shaft 20 and the operating lever 21 are configured to rotate together with each other. Alternatively, there may be employed a configuration in which the operating lever 21 is rotated without rotating the fastening shaft 20 and the nut 38.
In accordance with the relative rotation between the cam 23 and the cam follower 24, the cam 23 moves the cam follower 24 in the axial direction. The cam 23 performs the function of pressing the clamping side plate 29 (30) of the upper fixed bracket 19 against the clamped side plate 26 (27) of the upper column bracket 18. Thus, the brackets 18, 19 are locked, and tilt lock and telescopic lock are achieved.
A feature of the present embodiment is as follows. There are provided pressing members that are able to press the lower tube 12 (inner tube) through insertion holes of the upper tube 11 (outer tube) as the pressing members move in the axial direction Y1 of the fastening shaft 20 at the time of fastening by the fastening mechanism 17. In this way, telescopic lock of the tubes 11, 12 is ensured. A first pressing member 150 and a second pressing member 160 are provided as the pressing members. Each of the pressing members 150, 160 is fixed to the upper column bracket 18 (movable bracket).
Specifically, the first pressing member 150 has a body portion 151 and a pressing piece 152. The body portion 151 is fixed along the inner side face 26a of the clamped side plate 26 of the upper column bracket 18. The pressing piece 152 extends from the body portion 151 so as to be tilted (obliquely upward) with respect to the body portion 151. As shown in
Referring back to
The pressing piece 152 of the first pressing member 150 is able to press the lower tube 12 through an insertion hole 111a formed in the upper tube 11. The pressing piece 162 of the second pressing member 160 is able to press the lower tube 12 through an insertion hole 111b formed in the upper tube 11. The pressing piece 152 of the first pressing member 150 and the pressing piece 162 of the second pressing member 160 are tilted in opposite directions with respect to a vertical plane P1.
In the present embodiment, a slit 111c is formed in the upper tube 11 at a position between the pressing pieces 152, 162. The slit 111c extends in the axial direction X1 (direction perpendicular to the sheet on which
The upper column bracket 18, which may function as a movable bracket, is a groove-shaped member that opens upward, and is formed so as to be bilaterally symmetric. The upper column bracket 18 has the clamped side plates 26, 27 and the coupling plate 28. First end portions 261, 271 of the respective clamped side plates 26, 27 are fixed to the outer periphery of the upper tube 11. The coupling plate 28 couples second end portions 262, 272 of the clamped side plates 26, 27. That is, the second end portions 262, 272 of the clamped side plates 26, 27 are coupled to end portions 281, 282 of the coupling plate 28, respectively.
A flexible portion 28a is formed in a middle portion of the coupling plate 28. The flexible portion 28a is elastically deformable such that a distance D1 between the clamped side plates 26, 27 is reduced. The flexible portion 28a may be an inverted V-shaped portion as shown in
The clamped side plates 26, 27 of the upper column bracket 18 are arranged between the clamping side plates 29, 30 of the upper fixed bracket 19. The upper fixed bracket 19 is fixed to the vehicle body 14 via the mounting members 33 coupled to the mounting stay 32. The mounting members 33 each are coupled to the mounting stay 32 with the synthetic resin pins 34 that pass through the mounting stay 32 in the up-down direction. The synthetic resin pins 34 may break. The mounting members 33 each are fixed to the vehicle body 14 with the fixing bolt 35.
The outer side faces of the corresponding clamped side plates 26, 27 of the upper column bracket 18 are arranged along inner side faces 29a, 30a of the clamping side plates 29, 30 of the upper fixed bracket 19. The transversely long holes 36 for telescopic adjustment are formed in the clamped side plates 26, 27 of the upper column bracket 18. The transversely long holes 36 extend in a direction perpendicular to the sheet on which
The fastening mechanism 17 includes the fastening shaft 20, a nut 38, the cam 23 and the cam follower 24. The fastening shaft 20 is passed through the vertically long holes 37 of the clamping side plates 29, 30 of the upper fixed bracket 19 and the transversely long holes 36 of the clamped side plates 26, 27 of the upper column bracket 18. The nut 38 is screwed to a threaded portion formed at one end portion of the fastening shaft 20. The cam 23 and the cam follower 24 are fitted to an outer peripheral portion near the other end portion of the fastening shaft 20. The cam 23 and the cam follower 24 constitute the cam mechanism 22.
The head 201 is formed at the other end portion of the fastening shaft 20. The head 201 of the fastening shaft 20 and the cam 23 are coupled to the operating lever 21 so as to be rotatable together with the operating lever 21. That is, by operating the operating lever 21, the pressing members 150, 160 push up the lower tube 12 (inner tube) with the use of the pressing pieces 152, 162. Thus, the lower tube 12 is radially pressed against the upper tube 11 (outer tube), and a backlash of the lower tube 12 in the radial direction with respect to the upper tube 11 is suppressed.
The cam follower 24 has the first portion 241 and the second portion 242. The first portion 241 of the cam follower 24 is arranged along the outer side face 29b of the clamping side plate 29 of the upper fixed bracket 19. The second portion 242 of the cam follower 24 is fitted into the vertically long hole 37 of the clamping side plate 29 of the upper fixed bracket 19 and the transversely long hole 36 of the clamped side plate 26 of the upper column bracket 18 so as to be movable in the directions in which the long holes 37, 36 extend. By forming a width across flat, or the like, at a portion at which the second portion 242 is fitted in the vertically long hole 37 of the clamping side plate 29, the rotation of the second portion 242 is restricted by the vertically long hole 37.
The first intervening member 41 and the second intervening member 42 are interposed between the nut 38 screwed to one end portion of the fastening shaft 20 and the clamping side plate 30 of the upper fixed bracket 19. The first intervening member 41 has the first portion 412 and the second portion 411. The first portion 412 of the first intervening member 41 is arranged along the outer side face 30b of the clamping side plate 30 of the upper fixed bracket 19.
The second portion 411 of the first intervening member 41 is fitted in the vertically long hole 37 of the clamping side plate 30 of the upper fixed bracket 19 and the transversely long hole 36 of the clamped side plate 27 of the upper column bracket 18 so as to be movable in the directions in which the long holes 37, 36 extend. By forming a width across flat, or the like, at a portion at which the second portion 411 is fitted in the vertically long hole 37 of the clamping side plate 30, the rotation of the second portion 411 is restricted by the vertically long hole 37.
The second intervening member 42 includes the thrust washer 43 and the thrust needle roller bearing 44. The thrust washer 43 is interposed between the first portion 412 of the first intervening member 41 and the nut 38. The needle roller bearing 44 is interposed between the thrust washer 43 and the first portion 412 of the first intervening member 41. Due to the function of the second intervening member 42 that includes the needle roller bearing 44, the nut 38 is able to smoothly rotate together with the fastening shaft 20.
According to the present embodiment, the clamped side plates 26, 27 of the upper column bracket 18 are fastened via the clamping side plates 29, 30 of the upper fixed bracket 19 by the fastening shaft 20 in response of a rotating operation of the operating lever 21. Thus, both of the brackets 18, 19 are locked. In addition, at the time of fastening by the fastening shaft 20, the distance D1 between the clamped side plates 26, 27 of the upper column bracket 18 is reduced. Accordingly, the pressing members 150, 160 move in the axial direction Y1 of the fastening shaft 20, and the pressing pieces 152, 162 of the pressing members 150, 160 press the lower tube 12 (inner tube) through the insertion holes 111a, 111b of the upper tube 11 (outer tube), respectively. As a result, the lower tube 12 is pushed against the upper tube 11, and the tubes 11, 12 are reliably locked.
It is possible to use the entirety of the axial force of the fastening shaft 20 as a retaining force for retaining the posture of the steering column 8. Therefore, it is possible to increase the retaining force even when the operating force of the operating lever 21 is substantially the same as that in related art. Consequently, in the event of a secondary collision of a vehicle, it is possible to suppress changes in the posture of the steering column 8 before the tubes 11, 12 contract. Accordingly, at the time of absorbing a shock, it is possible to perform a desired shock absorbing function by appropriately contracting the tubes 11, 12.
The pressing pieces 152, 162 of the pressing members 150, 160 are tilted in opposite directions with respect to the vertical plane P1. Therefore, at the time of fastening by the fastening mechanism 17, the pressing pieces 152, 162, for example, cooperatively push up the lower tube 12 to press the lower tube 12 against the upper tube 11. In this way, it is possible to stably retain the posture of the steering column 8. In addition, at the time of fastening by the fastening mechanism 17, the flexible portion 28a of the coupling plate 28 that couples the clamped side plates 26, 27 of the upper column bracket 18 to each other elastically deforms. In this way, the distance D1 between the clamped side plates 26, 27 is reduced. Thus, it is possible to reliably place the tubes 11, 12 in the locked state by ensuring sufficient displacements of the pressing members 150, 160 in the axial direction of the fastening shaft 20.
In related art in which the lower tube is pushed up by the cam provided on the outer periphery of the sleeve that rotates together with the fastening shaft, an region of the lower tube in the axial direction, which the cam contacts, is short. In contrast to this, in the present embodiment in which the pressing members 150, 160 are moved in the axial direction Y1 of the fastening shaft 20, it is possible to extend the region of the lower tube 11 in the axial direction X1, which the pressing piece 152 contacts, by extending the pressing piece 152 in the axial direction X1 of the lower tube 12. In terms of this point as well, it is possible to reliably place the tubes 11, 12 in the locked state. Note that, in the present embodiment, the slit 111c of the upper tube 11 may be omitted.
Next,
The first upper column bracket 18P has a first side plate 171, a second side plate 172 and a coupling plate 173. The first side plate 171 is a clamped side plate that is arranged along the inner side face 29a of the clamping side plate 29 of the upper fixed bracket 19. The second side plate 172 faces the inner side face of the first side plate 171. The coupling plate 173 couples the first side plate 171 and the second side plate 172 to each other. The first side plate 171 has a first end portion 711 and a second end portion 712, and the second side plate 172 has a first end portion 721 and a second end portion 722. The first end portions 711, 721 are fixed to the upper tube 11. The second end portions 712, 7122 are coupled to end portions 731, 732 of the coupling plate 173, respectively. The first pressing member 150 is fixed to the inner side face of the first side plate 171 that may function as a clamped side plate.
The second upper column bracket 18Q has a first side plate 181, a second side plate 182 and a coupling plate 183. The first side plate 181 is a clamped side plate that is arranged along the inner side face 30a of the clamping side plate 30 of the upper fixed bracket 19. The second side plate 182 faces the inner side face of the first side plate 181. The coupling plate 183 couples the first side plate 181 and the second side plate 182 to each other. The first side plate 181 has a first end portion 811 and a second end portion 812, and the second side plate 182 has a first end portion 821 and a second end portion 822. The first end portions 811, 821 are fixed to the outer periphery of the upper tube 11. The second end portions 812, 822 are coupled to end portions 831, 832 of the coupling plate 183, respectively. The second pressing member 160 is fixed to the inner side face of the first side plate 181 that may function as a clamped side plate.
The slit 111c is formed in the upper tube 11. The slit 111c extends in the axial direction X1. The first end portions 711, 721 of the first side plate 171 and second side plate 172 of the first upper column bracket 18P and the first end portions 811, 821 of the first side plate 181 and second side plate 182 of the second upper column bracket 18Q are fixed to the outer periphery of the upper tube 11 on respective sides of the slit 111c.
Among the components in the embodiment shown in
At the time of fastening by the fastening mechanism 17, the diameter of the upper tube 11 with the slit 111c is reduced. Therefore, it is possible to bring the upper column brackets 18P, 18Q, which are arranged on respective sides of the slit 111c, close to each other in the axial direction Y1 of the fastening shaft 20. As a result, it is possible to reliably place the tubes 11, 12 in the locked state by ensuring sufficient displacements of the pressing members 150, 160 in the axial direction Y1 of the fastening shaft 20.
In the above-described embodiment, the nut 38, the fastening shaft 20 and the operating lever 21 are configured to rotate together with each other. Alternatively, there may be employed a configuration in which the operating lever 21 is rotated without rotating the fastening shaft 20 and the nut 38. The invention is not limited to the above-described embodiments, and various modifications may be made within the scope of the appended claims.
Claims
1. A position adjustable steering device, comprising:
- a steering column that includes an outer tube and an inner tube that are fitted to each other so as to be relatively slidable in an axial direction of the steering column to make telescopic adjustment, and that support a steering shaft such that the steering shaft is rotatable;
- a fixed bracket that has a pair of clamping side plates, and that is fixed to a vehicle body;
- a movable bracket that has a pair of clamped side plates arranged along inner side faces of the respective clamping side plates, and that is fixed to the outer tube;
- a fastening mechanism that includes a fastening shaft that passes through the clamping side plates and the clamped side plates, and that achieves telescopic lock by fastening the clamped side plates with use of the fastening shaft via the clamping side plates in accordance with a rotating operation of an operating lever;
- an insertion hole that is formed in the outer tube; and
- a pressing mechanism that moves in an axial direction of the fastening shaft in accordance with fastening by the fastening shaft, and that has a pressing member that presses the inner tube through the insertion hole,
- wherein:
- a plurality of the insertion holes are formed in a lower side portion of the outer tube,
- the pressing mechanism has a first pressing member and a second pressing member each of which has a body portion fixed to the movable bracket and a pressing piece extending from the body portion, and which are fixed to the respective clamped side plates,
- the pressing piece of the first pressing member and the pressing piece of the second pressing member are tilted in opposite directions with respect to a vertical plane, and
- the pressing mechanism is configured such that the pressing pieces of the pressing members press the inner tube through the insertion holes in directions that are tilted with respect to the fastening shaft in accordance with fastening by the fastening mechanism.
2. The position adjustable steering device according to claim 1, wherein:
- the movable bracket includes a coupling plate that couples the clamped side plates to each other;
- each of the clamped side plates has a first end portion fixed to the outer tube and a second end portion coupled to a corresponding one of end portions of the coupling plate; and
- the coupling plate has a flexible portion that is elastically deformable such that a distance between the clamped side plates is reduced.
3. The position adjustable steering device according to claim 2, wherein:
- a first movable bracket and a second movable bracket are provided as the movable bracket;
- each of the first movable bracket and the second movable bracket has a first side plate that serves as the clamped side plate arranged along a corresponding one of the clamping side plates of the fixed bracket, a second side plate that faces the first side plate, and a coupling plate that couples the first side plate and the second side plate to each other;
- each of the first side plate and the second side plate has a first end portion fixed to the outer tube and a second end portion coupled to a corresponding one of end portions of the coupling plate;
- a slit extending in an axial direction of the outer tube is formed in the outer tube; and
- the first end portions of the first side plate and the second side plate of the first movable bracket, and the first end portions of the first side plate and the second side plate of the second movable bracket are fixed to the outer tube on respective sides of the slit.
Type: Application
Filed: Dec 19, 2014
Publication Date: Apr 16, 2015
Inventor: Eiji TANAKA (Kitakatsuragi-gun)
Application Number: 14/577,918
International Classification: B62D 1/184 (20060101); B62D 1/185 (20060101);