JP5212714B2 - Vehicle shock absorption steering system - Google Patents

Description

  The present invention relates to an impact absorbing steering device for a vehicle.

  The vehicle steering apparatus includes a steering shaft and a steering column that rotatably supports the steering shaft. The steering column has an outer tube and an inner tube fitted to each other. 2. Description of the Related Art There has been proposed a vehicle impact absorption steering device that absorbs an impact by moving an outer tube and an inner tube relative to each other in the event of a vehicle collision (see, for example, Patent Documents 1 and 2).

Usually, the vehicle steering device has a steering lock device for crime prevention. The steering lock device has a cylindrical key lock collar fixed to the steering shaft, and a lock pin held by the steering column so as to be able to advance and retract. When the lock pin and the key lock collar are engaged with each other, the rotation of the steering shaft is restricted.
JP 2006-264424 A Japanese Utility Model Publication No. 6-79589

In Patent Document 1, in order to ensure a large amount of shock absorption stroke, the inner tube enters a gap between the outer periphery of the key lock collar and the inner periphery of the outer tube in the event of a vehicle collision. . However, since the inner tube passes outside the key lock collar, the outer tube is enlarged.
On the other hand, miniaturization of the steering column is required. If the outer diameter of the outer tube is reduced in order to reduce the size, the gap between the outer periphery of the key lock collar and the inner periphery of the outer tube becomes narrow, so that the inner tube cannot pass through this gap. As a result, the shock absorbing stroke amount is reduced.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a small vehicle shock absorption steering device that can increase the amount of shock absorption stroke.

  The vehicle impact absorbing steering device (1) according to the present invention is capable of rotating a steering shaft (3) connected to a steering member (2) and the steering shaft via bearings (36, 37, 38, 39). A cylindrical key lock collar having a key column (116) for engaging a steering column (35) to be supported and an outer periphery (117) of the steering shaft and engaging with a lock pin (42) for steering lock. (44), and the steering column includes an outer jacket (55) and an inner jacket (54) that are fitted to each other so as to be relatively movable in the axial direction (A1) of the steering shaft. An outer tube (56, 56A) surrounding the key lock collar, The cross section of the groove is relatively long in the first direction (C1) out of the first and second directions (C1, C2) orthogonal to each other and relatively short in the second direction (C2). The inner jacket has a shape and the inner tube (58) that does not fit into the outer tube, and extends from the one end (133) of the inner tube upward in the axial direction, and the inner periphery (119) of the outer tube. A pair of fitting plates (59, 59A) having a groove shape or a U-shaped cross section fitted to each other, and the pair of fitting plates in the first direction across the central axis (132) of the inner tube. When the outer jacket and the inner jacket move relative to each other along the axial direction when the vehicle collides, the pair of fitting plates move the inner tube of the outer tube. And wherein that you have to be inserted into the insertion space (120) between the key lock outer periphery of the collar (114) (claim 1).

According to the present invention, when the vehicle collides, the pair of fitting plates and the outer tube relatively move in the axial direction, and the pair of fitting plates can be inserted into the insertion space, so that the relative movement amount can be increased. As a result, the amount of shrinkage of the steering column can be increased. Therefore, the shock absorbing stroke amount can be increased.
In addition, since the upper portion of the inner jacket is constituted by a pair of fitting plates facing in the first direction, the outer jacket and consequently the steering column are reduced in size in the second direction. Further, a pair of fitting plates facing each other are fitted into the outer tube, and each fitting plate has a groove shape or a U-shaped cross section. As a result, the rigidity (particularly bending rigidity) of the steering column can be increased.

  In the present invention, the outer tube (56) has a rectangular cross section, and each of the pair of fitting plates (59) has a groove shape including a web (136) and a pair of flanges (137). Each of the web and the pair of flanges may be fitted to a corresponding flat surface element (124, 125) on the inner circumference of the outer tube (claim 2). In this case, the outer tube and each fitting plate can be fitted to each other by at least three surface elements, and the connection rigidity and connection strength of the outer tube and each fitting plate can be improved.

  Further, in the present invention, a chamfered portion (126) is provided at a corner portion of the cross section of the outer tube, and the chamfered portion that fits into the chamfered portion of the outer tube is provided between the web and each of the flanges. There is a case where a portion (138) is provided (claim 3). In this case, the number of surface elements with which the outer tube and each fitting plate are fitted together can be increased, and the connection rigidity and connection strength of the outer tube and each fitting plate can be improved. Further, the outer jacket can be further reduced in size by the chamfered portion of the outer tube.

  In the present invention, the bearing includes a bearing (36) held by the outer jacket, and the inner tube and the key lock collar are separated from each other by a first predetermined distance (L1) in the axial direction. The bearings held by the outer jacket and the fitting plates are opposed to each other with a second predetermined distance (L2) apart from each other in the axial direction, and the first predetermined distance and the The second predetermined distance is made equal to each other, and there is a case where the contraction amount (L3) of the steering column at the time of a vehicle collision is regulated. In this case, the contraction amount of the steering column in the event of a vehicle collision, and hence the shock absorption stroke amount, can be ensured while ensuring the fitting length between the outer jacket and the inner jacket.

  In addition, although the alphanumeric characters in the parentheses indicate reference signs of corresponding components in the embodiments described later, the scope of the claims is not limited by these reference signs.

  A preferred embodiment of the present invention will be described with reference to the accompanying drawings. In the present embodiment, a description will be given based on a case where the shock absorbing steering device for a vehicle is an electric power steering device (EPS: Electric Power Steering System). FIG. 1 is a schematic diagram of a schematic configuration of a vehicle shock absorption steering apparatus according to a first embodiment of the present invention. Referring to FIG. 1, a vehicle impact absorbing steering device 1 includes a steering shaft 3 connected to a steering member 2 such as a steering wheel, and an intermediate connected to the steering shaft 3 via a first universal joint 4. The vehicle has a shaft 5, a pinion shaft 7 connected to the intermediate shaft 5 via a second universal joint 6, and rack teeth 9 that mesh with pinion teeth 8 provided near the end of the pinion shaft 7. And a rack bar 10 as a steered shaft extending in the left-right direction.

  The pinion shaft 7 and the rack bar 10 constitute a steering gear 11 composed of a rack and pinion mechanism. The rack bar 10 is supported in a rack housing 13 fixed to the vehicle body 12 so as to be linearly reciprocable via a plurality of bearings (not shown). A pair of tie rods 14 are coupled to the rack bar 10. Each tie rod 14 is connected to a corresponding steered wheel 16 via a corresponding knuckle arm (not shown).

When the steering member 2 is operated and the steering shaft 3 is rotated, this rotation is caused by the pinion teeth 8 and the rack teeth 9 in the rack in the left-right direction of the automobile (corresponding to the vertical direction in FIG. 1). It is converted into a linear motion of the bar 10. Thereby, the turning of the steered wheels 16 is achieved.
As will be described later, the steering shaft 3 includes an upper shaft 51, a lower shaft 52, an input shaft 17, a torsion bar 19, and an output shaft 18. The upper shaft 51, the lower shaft 52, the input shaft 17, the torsion bar 19, and the output shaft 18 are steered along the axial direction A1 of the steering shaft 3 (hereinafter also simply referred to as the axial direction A1). They are connected in order from the 2 side.

  The input shaft 17 is connected to the steering member 2 via the upper shaft 51 and the lower shaft 52. The input shaft 17 and the output shaft 18 are connected to each other on the same axis via a torsion bar 19. When steering torque is input to the input shaft 17, the torsion bar 19 is elastically torsionally deformed, whereby the input shaft 17 and the output shaft 18 are rotated relative to each other.

  A torque sensor 20 that detects a steering torque based on the amount of relative rotational displacement between the input shaft 17 and the output shaft 18 via the torsion bar 19 is provided. A vehicle speed sensor 21 for detecting the vehicle speed is also provided. An ECU (Electronic Control Unit) 22 is provided as a control device. Further, an electric motor 23 for generating a steering assist force and a speed reduction mechanism 24 for reducing the output rotation of the electric motor 23 are provided.

  Detection signals from the torque sensor 20 and the vehicle speed sensor 21 are input to the ECU 22. The ECU 22 controls the steering assisting electric motor 23 based on the torque detection result, the vehicle speed detection result, and the like. The output rotation of the electric motor 23 is decelerated via the speed reduction mechanism 24 and transmitted to the pinion shaft 7 and converted into a linear motion of the rack bar 10 to assist steering.

The speed reduction mechanism 24 includes a worm 26 as a drive gear and a worm wheel 27 as a driven gear that meshes with the worm 26. The worm 26 is disposed concentrically with an output shaft (not shown) of the electric motor 23 and is driven to rotate by the electric motor 23. The worm wheel 27 rotates together with the output shaft 18 and is connected so as not to move in the axial direction.
Further, the vehicle impact absorbing steering device 1 includes a steering column 35 that rotatably supports the steering shaft 3. The steering column 35 supports the steering shaft 3 via a first bearing 36, a second bearing 37, a third bearing 38, and a fourth bearing 39.

Further, the vehicle impact absorbing steering device 1 holds the lock pin 42 for restricting the rotation of the steering shaft 3 so that the rotation of the steering shaft 3 can be released and the lock pin 42 so as to be able to advance and retract to prevent the vehicle from being stolen. And a key lock collar 44 that is detachably engaged with the lock pin 42.
The key lock collar 44 is attached to the steering shaft 3 in the circumferential direction of the steering shaft 3 so as to be able to move together. When the lock pin 42 is engaged with the key lock collar 44, the lock pin 42 can regulate the rotation of the steering shaft 3 via the key lock collar 44. The lock pin 42 and the key lock collar 44 constitute at least a part of the steering lock device.

  The steering column 35 is supported on the vehicle body 12 by an upper support structure 47 and a lower support structure 48. The steering column 35 extends parallel to the axial direction A1 and extends in a direction inclined with respect to the longitudinal direction X1 of the vehicle. For example, the central axis of the steering shaft 3 is disposed obliquely with respect to the vehicle front-rear direction X1 so that the steering member 2 is on the upper side. In FIG. 1, the vertical direction Z1 is shown.

In addition, the vehicle impact absorbing steering apparatus 1 has an impact absorbing function for absorbing an impact when the driver collides with the steering member 2 (secondary collision) at the time of collision of the vehicle.
The shock absorbing function is realized by the upper support structure 47, the lower support structure 48, the retractable steering shaft 3 as described later, and the retractable steering column 35 as described later.

  FIG. 2 is a cross-sectional view of the main part of FIG. 1, and mainly shows the upper portions in the axial direction of the steering column 35 and the steering shaft 3. Referring to FIGS. 1 and 2, the steering shaft 3 includes an upper shaft 51 as a cylindrical outer shaft, a lower shaft 52 as an inner shaft, the input shaft 17 described above, and the output shaft 18 described above. And the torsion bar 19 described above.

The steering member 2 is connected to the upper end of the upper shaft 51 in the axial direction. The lower end in the axial direction of the upper shaft 51 and the upper end in the axial direction of the lower shaft 52 are fitted to each other. The upper shaft 51 and the lower shaft 52 are connected to each other by a joint structure such as a spline structure so as to be able to move relative to each other along the axial direction A1 and rotate together.
The lower end portion in the axial direction of the lower shaft 52 and the upper end portion in the axial direction of the input shaft 17 are connected to each other so as to be able to rotate together.

The steering column 35 includes a column jacket 53 that accommodates a part of the steering shaft 3 and a housing 78 that accommodates the speed reduction mechanism 24. Further, the torque sensor 20 and the electric motor 23 are disposed in the housing 78.
The column jacket 53 constitutes an upper part and an intermediate part of the steering column 35 in the axial direction A1.

  The column jacket 53 has an inner jacket 54 and an outer jacket 55. The inner jacket 54 and the outer jacket 55 are arranged in this order from the lower side in the axial direction to the axial direction A1. The outer periphery of the upper end in the axial direction of the inner jacket 54 is fitted to the inner periphery of the lower end in the axial direction of the outer jacket 55 so as to be relatively movable in the axial direction A1.

The outer jacket 55 includes an outer tube 56 that surrounds the key lock collar 44 and a cylindrical bearing holding portion 57 that holds the first bearing 36. The outer tube 56 and the bearing holding portion 57 are integrally formed of a single material.
The outer tube 56 is disposed below the bearing holding portion 57 in the axial direction. The outer tube 56 extends in the axial direction A1. The lower end portion in the axial direction of the outer tube 56 is fitted with the inner jacket 54. The outer tube 56 has a portion that can slide relative to the inner jacket 54 in the event of a vehicle collision, for example, the entire region in the axial direction A1.

  FIG. 3 is an exploded perspective view of the column jacket 53 shown in FIG. 2, partially showing a cross section. Referring to FIGS. 2 and 3, the inner jacket 54 includes an inner tube 58 that does not fit with the outer tube 56, and a pair of groove-shaped fitting plates 59. The inner tube 58 and the pair of fitting plates 59 are formed separately from each other and are fixed to each other. For example, the inner tube 58 and each fitting plate 59 are welded to each other. Further, the inner tube 58 and the pair of fitting plates 59 may be integrally formed of a single material.

  FIG. 4 is a cross-sectional view of the main part of FIG. 2, and mainly shows the upper part in the axial direction of the outer jacket 55 and the upper shaft 51. Referring to FIG. 4, the bearing holding portion 57 of the outer jacket 55 holds the first bearing 36, and supports the upper shaft 51 through the first bearing 36 in a rotatable manner. Further, the axial relative movement between the outer jacket 55 and the upper shaft 51 is restricted.

Specifically, the first bearing 36 is a ball bearing as a rolling bearing. The first bearing 36 includes an inner ring 61, an outer ring 62, and a plurality of balls 63 as rolling elements that are interposed between the inner ring 61 and the outer ring 62 so as to allow rolling.
The upper shaft 51 is formed with a fitting portion 64 including an outer peripheral surface with which the inner ring 61 is fitted, a step portion 65, and a circumferential groove 66. The step portion 65 and the circumferential groove 66 are disposed on opposite sides of the axial direction A1 with the fitting portion 64 interposed therebetween. A retaining ring 67 as a fixing member for fixing the inner ring 61 is engaged with the circumferential groove 66. The inner ring 61 of the first bearing 36 is disposed between the step portion 65 of the upper shaft 51 and the retaining ring 67. Thereby, the axial movement of the inner ring 61 of the first bearing 36 is restricted.

  The bearing holding portion 57 of the outer jacket 55 includes a fitting portion 68 formed of an inner peripheral surface to which the outer ring 62 of the first bearing 36 is fitted, and an annular end extending radially inward from the end edge of the fitting portion 68. And a wall 69. A cylindrical cover 70 is attached to the outer periphery of the bearing holding portion 57. The cover 70 has a flange portion 71 extending inward in the radial direction. The flange portion 71 and the end wall 69 are opposed to each other in the axial direction A1 with the outer ring 62 interposed therebetween. The outer ring 62 of the first bearing 36 is disposed between the end wall 69 of the bearing holding portion 57 and the flange portion 71 of the cover 70. Thereby, the axial movement of the outer ring 62 of the first bearing 36 is restricted.

  With reference to FIGS. 1 and 2, the upper support structure 47 supports the lower end portion in the axial direction of the outer jacket 55. The upper support structure 47 has an upper fixing bracket 75 supported in a fixed state on the vehicle body 12 via a connecting member 74. The upper fixing bracket 75 supports the lower end of the outer jacket 55 with respect to the axial direction A1, and restricts the relative movement of the outer jacket 55 with respect to the axial direction A1.

The connecting member 74 holds the upper fixing bracket 75 on the vehicle body 12 with a predetermined holding force. As a result, the relative movement between the upper fixing bracket 75 and the vehicle body 12 is restricted during normal times. Further, the relative movement between the upper fixing bracket 75 and the vehicle body 12 is allowed at the time of a vehicle collision in which an impact force exceeding a predetermined holding force acts.
With reference to FIG. 1, the housing 78 is connected to the lower end portion in the axial direction of the inner tube 58 of the inner jacket 54. The housing 78 holds the second bearing 37. The second bearing 37 is a ball bearing as a rolling bearing. The housing 78 rotatably supports the input shaft 17 via the second bearing 37.

  FIG. 5 is a cross-sectional view of the main part of FIG. Referring to FIGS. 1 and 5, the housing 78 holds a third bearing 38 and a fourth bearing 39. The third bearing 38 is a ball bearing as a rolling bearing. The fourth bearing 39 is a ball bearing as a rolling bearing. The housing 78 rotatably supports the output shaft 18 via the third bearing 38 and the fourth bearing 39.

Further, the housing 78 restricts the axial movement of the output shaft 18 via the fourth bearing 39, and consequently restricts the axial movement of the input shaft 17 and the lower shaft 52. Specifically, the fourth bearing 39 includes an inner ring 85, an outer ring 86, and a plurality of balls 87 as rolling elements that are interposed between the inner ring 85 and the outer ring 86 so as to allow rolling.
The output shaft 18 includes a fitting portion 88 formed of an outer peripheral surface to which the inner ring 85 of the fourth bearing 39 is fitted, and an annular step portion 89 extending radially outward from the edge portion of the fitting portion 88. And a male screw part 90. The male screw portion 90 and the stepped portion 89 are arranged on opposite sides with respect to the axial direction A1 with the fitting portion 88 interposed therebetween. An annular female screw member 91 as a fixing member for fixing the inner ring 85 is engaged with the male screw portion 90. The inner ring 85 of the fourth bearing 39 is disposed between the step portion 89 and the female screw member 91. Thereby, the axial movement of the inner ring 85 of the fourth bearing 39 is restricted.

  The housing 78 includes a fitting portion 92 formed of an inner peripheral surface into which the outer ring 86 of the fourth bearing 39 is fitted, an annular end wall 93 extending radially inward from the end edge of the fitting portion 92, and a circumferential groove. 94. The circumferential groove 94 and the end wall 93 are disposed on opposite sides with respect to the axial direction A1 with the fitting portion 92 interposed therebetween. A retaining ring 95 as a fixing member for fixing the outer ring 86 is engaged with the circumferential groove 94. The outer ring 86 of the fourth bearing 39 is disposed between the end wall 93 of the housing 78 and the retaining ring 95. Thereby, the axial movement of the outer ring 86 of the fourth bearing 39 is restricted.

Further, the housing 78 constitutes the lower part of the steering column 35 in the axial direction A1. The housing 78 is supported on the vehicle body 12 by the lower support structure 48.
The lower support structure 48 is interposed between the lower fixing bracket 98 supported by the vehicle body 12 in a fixed state, the supported member 99 supported by the lower fixing bracket 98, and the lower fixing bracket 98 and the supported member 99. And a support shaft 100 that connects the two to each other. The supported member 99 is supported by the lower fixing bracket 98 via the support shaft 100. Further, the supported member 99 is fixed to a housing 78 as a lower part of the steering column 35. Specifically, the supported member 99 and the housing 78 are integrally formed of a single material. The housing 78 is supported by the vehicle body 12 via a supported member 99, a support shaft 100, and a lower fixing bracket 98.

  FIG. 6 is a cross-sectional view of the VI-VI cross section shown in FIG. 2, partially showing the cross section. With reference to FIGS. 2 and 6, the lock device main body 43 is fixed to the outer periphery 121 of the outer tube 56. The lock device main body 43 is provided with a mechanism (not shown) for driving the lock pin 42 in order to engage and disengage the lock pin 42 with the key lock collar 44. The mechanism unit can drive the lock pin 42 by a cam mechanism in conjunction with a manual operation, for example. Alternatively, the mechanism unit may be configured to drive the lock pin 42 via a cam mechanism by driving an actuator.

The outer tube 56 has a through hole 112. When the lock pin 42 is advanced from the lock device main body 43, the lock pin 42 can pass through the through hole 112, and can thereby be engaged with the key lock collar 44.
The key lock collar 44 has a cylindrical shape with a circular cross section. The key lock collar 44 has an outer periphery 114 and an inner periphery 115. On the outer periphery 114 of the key lock collar 44, key lock holes 116 are formed at a plurality of locations in the circumferential direction.

The key lock hole 116 is a groove extending in parallel with the axial direction A1. Note that at least one key lock hole 116 may be provided. The key lock hole 116 may penetrate the key lock collar 44 in the radial direction or may not penetrate the key lock collar 44.
The key lock collar 44 and the lock pin 42 are disposed opposite to each other in the radial direction of the steering shaft 3. With respect to the axial direction A1, the center position of the key lock hole 116 and the center position of the lock pin 42 are aligned. The key lock collar 44 is fixed to the outer periphery 117 of the upper shaft 51 of the steering shaft 3 in a press-fit state, for example.

Note that the key lock collar 44 may be fixed to the upper shaft 51 so as not to be relatively movable, or may be moved in a predetermined manner so that the key shaft can be relatively moved when a torque exceeding a predetermined holding torque is applied to the upper shaft 51. It may be fixed by holding force.
In the steering lock state, the tip of the lock pin 42 advances from the lock device main body 43 into the steering column 35 and engages with the edge of the key lock hole 116 of the key lock collar 44. As a result, steering lock is achieved. Further, when the steering lock is released, the lock pin 42 retracts into the lock device main body 43. Thereby, the engagement between the lock pin 42 and the key lock collar 44 is released.

  FIG. 7 is a schematic diagram of a schematic configuration of a main part of the vehicle shock absorption steering device 1 of FIG. 1, and shows a state when the shock is absorbed. Moreover, the state before shock absorption is shown in FIG. Referring to FIGS. 1 and 7, the inner jacket 54 and the outer jacket 55 can be moved relative to each other in the axial direction A1 in the event of a vehicle collision. Specifically, the outer jacket 55 moves relative to the inner jacket 54 toward the front of the vehicle.

In the present embodiment, an annular insertion space 120 is defined between the inner periphery 119 of the outer tube 56 and the outer periphery 114 of the key lock collar 44. A fitting plate 59 of the inner jacket 54 is inserted into the insertion space 120 in the event of a vehicle collision.
Referring to FIGS. 3 and 6, the axially perpendicular cross section of the outer tube 56 is relatively long in the first direction C1 out of the first direction C1 and the second direction C2 orthogonal to each other, and the second direction A relatively short shape is formed on C2. Here, the cross section perpendicular to the axis of the outer tube 56 corresponds to a cross section perpendicular to the axial direction A1 of the steering shaft 3. In the present embodiment, the cross section perpendicular to the axis of the outer tube 56 is elongated in the vertical direction Z1.

The outer tube 56 has an inner periphery 119 and an outer periphery 121. The thickness of the outer tube 56 is constant in the circumferential direction.
An inner periphery 119 of the outer tube 56 has a plurality of flat surface elements 124, 125, and 126. That is, the inner periphery 119 includes a pair of first flat surfaces 124 as surface elements facing each other in the first direction C1 and a pair of second flat surfaces as surface elements facing each other in the second direction C2. 125 and four chamfered portions 126 as surface elements. Each chamfered portion 126 connects the corresponding first flat surface 124 and the corresponding second flat surface 125 to each other. Each chamfer 126 is a flat surface.

The inner periphery 119 of the outer tube 56 has a rectangular cross section. That is, the pair of first flat surfaces 124 and the pair of second flat surfaces 125 form a rectangle. A chamfered portion 126 is provided at the corner of the rectangle.
The outer periphery 121 of the outer tube 56 has a plurality of flat surface elements 128, 129, and 130. That is, the outer periphery 121 has a pair of first flat surfaces 128 as surface elements facing each other in the first direction C1 and a pair of second flat surfaces 129 as surface elements facing each other in the second direction C2. And four chamfered portions 130 as surface elements. Each chamfer 130 connects the corresponding first flat surface 128 and the corresponding second flat surface 129 to each other. Each chamfer 130 is a flat surface.

The outer periphery 121 of the outer tube 56 has a rectangular cross section. That is, the pair of first flat surfaces 128 and the pair of second flat surfaces 129 form a rectangle. A chamfered portion 130 is provided at the corner of the rectangle.
The chamfered portion 126 of the inner periphery 119 may form a concave curved surface. Further, the chamfered portion 130 of the outer periphery 121 may form a convex curved surface. In the present embodiment, a description will be given in accordance with a case where the chamfered portions 126 and 130 are flat surfaces.

2 and 3, the inner tube 58 has a circular cross section.
The pair of fitting plates 59 oppose each other in the first direction C1 with the central axis 132 of the inner tube 58 interposed therebetween.
Each fitting plate 59 extends from one end 133 of the inner tube 58 upward in the axial direction A1. Each fitting plate 59 is fitted to the inner periphery 119 of the outer tube 56.

Each fitting plate 59 has a groove shape. Each fitting plate 59 has a web 136 and a pair of flanges 137. The axial ends of the web 136 and the pair of flanges 137 are connected to the inner tube 58.
Each fitting plate 59 has a pair of chamfered portions 138 provided between the web 136 and each flange 137.

  One chamfered portion 138 connects the flat surface 140 formed by the web 136 and the flat surface 141 formed by one flange 137 to each other. The other chamfered portion 138 connects the flat surface 140 formed by the web 136 and the flat surface 141 formed by the other flange 137 to each other. Each chamfered portion 138 has a flat surface. Each chamfered portion 138 is fitted into a corresponding chamfered portion 126 on the inner periphery 119 of the outer tube 56.

The flat surface 140 formed by the web 136, the respective flat surfaces 141 of the pair of flanges 137, and the pair of chamfered portions 138 are fitted into the corresponding flat surface elements 124, 125, 126 of the inner periphery 119 of the outer tube 56. Match.
Specifically, the flat surface 140 formed by the web 136 is in contact with the first flat surface 124. The flat surface 141 formed by the flange 137 and the second flat surface 125 are in contact with each other. The chamfered portion 138 of the fitting plate 59 and the chamfered portion 126 of the inner periphery 119 of the outer tube 56 are in contact with each other.

Further, the angle of each chamfered portion 138 of the fitting plate 59 with respect to the first direction C1 and the angle with respect to each chamfered portion 126 of the inner periphery 119 of the outer tube 56 with respect to the first direction C1 are equal to each other.
Further, the distance between the first flat surfaces 124 of the inner periphery 119 of the outer tube 56 in the first direction C1, and the distance between the flat surfaces 140 formed by the web 136 of the pair of fitting plates 59 in the first direction C1. Are equal to each other.

Further, the distance between the second flat surfaces 125 of the inner periphery 119 of the outer tube 56 in the second direction C2 and the distance between the flat surfaces 141 formed by the flanges 137 of the respective fitting plates 59 in the second direction C2. , Are equal to each other.
With reference to FIG. 1, in the present embodiment, the inner tube 58 and the key lock collar 44 are separated from each other by the first predetermined distance L1 in the axial direction A1 before the collision. At the same time, each fitting plate 59 and the first bearing 36 are separated by a second predetermined distance L2 in the axial direction A1. The first predetermined distance L1 and the second predetermined distance L2 may be different from each other or may be equal to each other. In the present embodiment, a description will be given based on the case where the first predetermined distance L1 and the second predetermined distance L2 are equal to each other.

  Referring to FIG. 7, in the event of a vehicle collision, the steering member 2 can move downward in the axial direction by an impact absorption stroke amount L3. At this time, each fitting plate 59 of the inner tube 58 can reach the end of the outer jacket 55, for example, the first bearing 36 through the insertion space 120. Further, the end surface of the inner tube 58 can reach the end surface on the lower side in the axial direction of the key lock collar 44 with respect to the axial direction A1.

With reference to FIG. 1 and FIG. 7, in the present embodiment, a description will be given based on a case where the contraction amount of the steering column 35 and the shock absorption stroke amount L3 are equal to each other at the time of a vehicle collision.
The amount of contraction of the steering column 35 in the event of a vehicle collision, and hence the shock absorption stroke amount L3, is determined by the smaller value of the first predetermined distance L1 and the second predetermined distance L2. Therefore, in the present embodiment, the shock absorbing stroke amount L3 is equal to the first predetermined distance L1 and also equal to the second predetermined distance L2.

  When the first predetermined distance L1 and the second predetermined distance L2 are equal to each other, the fitting length L4 of the inner jacket 54 and the outer jacket 55 is ensured to be long, and the rigidity of the steering column 35 is ensured, while the shock absorbing stroke. The amount L3 can also be secured. Here, the fitting length L4 described above corresponds to the contact length between the inner periphery 119 of the outer tube 56 and the fitting plate 59 in the axial direction A1.

When the vehicle collides, the inner tube 58 may not reach the key lock collar 44 in some cases. At this time, each fitting plate 59 also does not reach the first bearing 36.
In normal times before absorbing the shock, the inner jacket 54 and the outer jacket 55 are not moved relative to each other.

When the vehicle collides, the driver (driver) hits the steering member 2. Along with this, an impact force exceeding a predetermined holding force of the connecting member 74 acts. On the other hand, the movement of the lower shaft 52 and the inner jacket 54 is restricted in the axial direction A1.
As a result, when the shock is absorbed in the steering unlock state, the steering member 2, the upper shaft 51 of the steering shaft 3, the first bearing 36, and the outer jacket 55 are accompanied in the axial direction A1 toward the front of the vehicle body. Moving. Each of these members 2, 51, 36, 56 moves relative to the inner jacket 54. As a result, the steering column 35 and the steering shaft 3 contract. Impact energy is absorbed.

When the steering column 35 contracts, each fitting plate 59 is not in contact with the key lock collar 44. For example, when viewed in the axial direction A <b> 1, a gap is opened between each fitting plate 59 and the outer periphery 114 of the key lock collar 44. Further, the flanges 137 of the pair of fitting plates 59 are notched.
Further, in the present embodiment, the cross section of the outer tube 56 can be made smaller in the second direction C2 than in the first direction C1. As a result, the steering column 35 can be downsized in the second direction C2.

  For example, since a peripheral device is attached to the steering column 35, the space around the steering column 35 tends to be easily restricted. In particular, the space may be constrained in the second direction C2 (eg, lateral direction), but may not be constrained in the first direction C1 (eg, vertical direction). On the other hand, the outer diameter of the key lock collar 44 for steering lock cannot generally be made too small. Even in such circumstances, the present embodiment can ensure a large amount of shock absorption stroke.

The peripheral device described above can be exemplified by a combination switch for operating an electrical component (for example, a winker, a wiper, etc.) in addition to the steering lock device described above.
In the present embodiment, the outer diameter of the steering column 35 required for attaching the peripheral device can be realized with a required value, and a high impact absorbing function can be achieved. Therefore, it is possible to apply the present vehicle impact absorption steering apparatus 1 to a wide variety of vehicles.

  As described above with reference to FIGS. 1 and 7, the vehicle impact absorption steering apparatus 1 of the present embodiment includes the steering shaft 3 coupled to the steering member 2 and the steering shaft 3 in the first and second directions. In order to engage the steering column 35 rotatably supported via the third and fourth bearings 36, 37, 38, 39 and the outer periphery 117 of the steering shaft 3, and to engage the lock pin 42 for steering lock A cylindrical key lock collar 44 having a key lock hole 116. The steering column 35 includes an outer jacket 55 and an inner jacket 54 that are fitted to each other so as to be relatively movable in the axial direction A1 of the steering shaft 3. The outer jacket 55 includes an outer tube 56 that surrounds the key lock collar 44. The outer tube 56 has a cross section that is relatively long in the first direction C1 and relatively short in the second direction C2 of the first and second directions C1 and C2 orthogonal to each other. The inner jacket 54 includes an inner tube 58 that does not fit to the outer tube 56, and a pair of groove-shaped fittings that extend from one end 133 of the inner tube 58 in the axial direction A 1 and fit to the inner periphery 119 of the outer tube 56. Plywood 59 is included. The pair of fitting plates 59 oppose each other in the first direction C1 with the central axis 132 of the inner tube 58 interposed therebetween. In the event of a vehicle collision, as the outer jacket 55 and the inner jacket 54 move relative to each other along the axial direction A1, the pair of fitting plates 59 are formed between the inner periphery 119 of the outer tube 56 and the outer periphery 114 of the key lock collar 44. It is made to insert in the insertion space 120 between.

According to the present embodiment, when the vehicle collides, the pair of fitting plates 59 and the outer tube 56 move relative to each other in the axial direction A1, and the pair of fitting plates 59 can be inserted into the insertion space 120. Can be increased. As a result, the amount of contraction of the steering column 35 can be increased. Therefore, the shock absorbing stroke amount can be increased.
Moreover, since the upper portion of the inner jacket 54 in the axial direction is constituted by a pair of fitting plates 59 facing the first direction C1, the outer jacket 55 and consequently the steering column 35 are downsized in the second direction C2. The

A pair of fitting plates 59 facing each other are fitted to the outer tube 56, and each fitting plate 59 has a groove shape. As a result, the rigidity (particularly the bending rigidity) of the steering column 35 can be increased.
Since the cross section of the outer tube 56 is relatively long in the first direction C1, the cross section coefficient of the outer tube 56 with respect to the axis parallel to the first direction C1 increases. As a result, the outer tube 56 is difficult to bend in the vertical direction parallel to the first direction C1 in the present embodiment, for example.

  Referring to FIG. 6, in the present embodiment, outer tube 56 has a rectangular cross section. Each of the pair of fitting plates 59 has a groove shape including a web 136 and a pair of flanges 137. Each of the web 136 and the pair of flanges 137 is fitted to first and second flat surfaces 124 and 125 as corresponding flat surface elements of the inner periphery 119 of the outer tube 56.

In this case, the outer tube 56 and each fitting plate 59 can be fitted to each other by at least three surface elements, and the connection rigidity and connection strength of the outer tube 56 and each fitting plate 59 can be improved. Thereby, for example, the rigidity and strength of the assembly of the inner jacket 54 and the outer jacket 55 can be increased.
In the present embodiment, the chamfered portion 126 is provided at the corner of the cross section of the outer tube 56. Between the web 136 and each flange 137, a chamfered portion 138 that fits into the chamfered portion 126 of the outer tube 56 is provided.

  In this case, the number of surface elements with which the outer tube 56 and the respective fitting plates 59 are fitted to each other can be increased as compared with the case where there is no chamfered portion. As a result, the connection rigidity and connection strength of the outer tube 56 and each fitting plate 59 can be improved. Further, the outer jacket 55 can be further reduced in size by the chamfered portion 126 of the outer tube 56.

  With reference to FIGS. 1 and 7, in the present embodiment, the inner tube 58 and the key lock collar 44 are opposed to each other in the axial direction A1 with a first predetermined distance L1. The first bearing 36 held by the outer jacket 55 and each fitting plate 59 are opposed to each other with a second predetermined distance L2 in the axial direction A1. The first predetermined distance L1 and the second predetermined distance L2 are equal to each other. The first predetermined distance L1 and the second predetermined distance L2 regulate the contraction amount of the steering column 35 when the vehicle collides. In this case, the contraction amount of the steering column 35 in the event of a vehicle collision, and thus the shock absorbing stroke amount L3, can be ensured long while securing the fitting length between the outer jacket 55 and the inner jacket 54.

Moreover, the following modifications can be considered about this embodiment. In the following description, the difference from the above-described embodiment will be mainly illustrated, and this point will be mainly described. Although explanation is omitted about other composition, it is the same as that of the above-mentioned embodiment, and attaches the same numerals.
For example, FIG. 8 is a cross-sectional view perpendicular to the axis of the main part of the vehicle impact absorbing steering apparatus 1 according to the second embodiment of the present invention, partially showing a cross-section, and the axial position of the cross section of FIG. It corresponds to the cross section at the same axial position. The fitting plate 59A of the inner jacket 54 and the outer tube 56A of the outer jacket 55 of the second embodiment shown in FIG. 8 are replaced with the fitting plate 59 of the inner jacket 54 and the outer tube 56 of the outer jacket 55 shown in FIG. Used.

Referring to FIG. 8, in the present embodiment, outer tube 56A has an oval cross section. The inner periphery 119 of the outer tube 56A has a pair of concave curved surfaces 144 as surface elements facing each other in the first direction C1, and a pair of flat surfaces 145 as surface elements facing each other in the second direction C2. Have.
Each fitting plate 59A has a U-shaped cross section. Each fitting plate 59A has a web 136A and a pair of flanges 137. The web 136A is curved. The convex curved surface 146 formed by the web 136A is fitted to the concave curved surface 144 as a corresponding surface element of the inner periphery 119 of the outer tube 56A. A flat surface 141 formed by each flange 137 is fitted to a flat surface 145 as a corresponding surface element of the inner periphery 119 of the outer tube 56A.

Further, the radius of curvature of the concave curved surface 144 and the radius of curvature of the convex curved surface 146 are equal to each other.
Further, the dimension of the inner periphery 119 of the outer tube 56A in the first direction C1 and the distance between the convex curved surfaces 146 formed by the web 136A of the pair of fitting plates 59A in the first direction C1 are equal to each other. .

Further, the dimension of the inner periphery 119 of the outer tube 56A in the second direction C2 and the distance between the flat surfaces 141 formed by the flanges 137 of the fitting plates 59A in the second direction C2 are equal to each other.
Even when each fitting plate 59A has a U-shaped cross section, the same effects as those of the first embodiment in which each fitting plate 59 has a groove shape can be obtained.

  Although not shown, in the first embodiment, the chamfered portion 126 of the outer jacket 55 and the chamfered portion 138 of each fitting plate 59 may be eliminated. In this case, the outer tube 56 and each fitting plate 59 can be fitted to each other by three surface elements. As a result, the connection rigidity and connection strength of the outer tube 56 and each fitting plate 59 can be improved.

Although not shown, in the second embodiment, a concave curved surface facing the second direction C2 is provided in the inner periphery 119 of the outer tube 56A instead of the flat surface 145 facing the second direction C2. May be. In this case, the cross section of the outer tube 56A has an elliptical shape or a shape approximating an elliptical shape.
Further, in each of the embodiments described above, the steering column 35 may be rotated 90 degrees when viewed in the axial direction A1. In this case, for example, the outer tubes 56 and 56A are relatively short in the vertical direction.

Further, in each of the above-described embodiments, an example in which the present invention is applied to a so-called column assist type electric power steering device has been described. The present invention may be applied to an assist type electric power steering apparatus.
In the above-described embodiment, the example in which the present invention is applied to the electric power steering apparatus that outputs the output of the electric motor as the steering assist force has been described, but the present invention is not limited thereto. For example, the present invention is applied to a steer-by-wire type vehicle impact absorption steering device or the like in which the mechanical connection between a steering member and a steered wheel is released and the steered wheel is steered by the output of an electric motor. Also good. Further, the present invention may be applied to an impact absorbing steering device for a manually steered vehicle that does not generate a steering assist force. In addition, various changes can be made within the scope of the matters described in the claims.

1 is a schematic diagram of a schematic configuration of a vehicle shock absorption steering apparatus according to a first embodiment of the present invention, showing a state before shock absorption. FIG. 2 is a cross-sectional view of a main part of FIG. 1 mainly showing a column jacket and an upper part of a steering shaft. FIG. 3 is an exploded perspective view of the column jacket shown in FIG. 2, partially showing a cross section. FIG. 3 is a cross-sectional view of a main part of FIG. 2 mainly showing an outer jacket and an upper shaft. It is sectional drawing of the principal part of FIG. 1, and mainly shows a housing and its inside. It is sectional drawing of the VI-VI cross section shown in FIG. 2, and is partially cross-sectionally displayed. It is a schematic diagram of the schematic structure of the principal part of the shock absorption steering apparatus for vehicles of FIG. 1, and shows the state when absorbing the shock. FIG. 5 is a cross-sectional view perpendicular to an axis of a main part of a shock absorbing steering device for a vehicle according to a second embodiment of the present invention, partially showing a cross section.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Vehicle shock absorption steering device, 2 ... Steering member, 3 ... Steering shaft, 35 ... Steering column, 36 ... First bearing, 37 ... Second bearing, 38 ... Third bearing, 39 ... Fourth Bearing, 42 ... Lock pin, 44 ... Key lock collar, 54 ... Inner jacket, 55 ... Outer jacket, 56, 56A ... Outer tube, 58 ... Inner tube, 59, 59A ... Fitting plate, 114 ... Outer circumference of key lock collar, 116: Key lock hole, 117: Outer periphery (outer periphery of steering shaft), 119: Inner periphery of outer tube, 120: Insertion space, 124: First flat surface (corresponding flat surface element of inner periphery of outer tube) 125 ... second flat surface (corresponding flat surface element of the inner periphery of the outer tube), 126 ... chamfered portion (chamfering of the outer tube) Part), 132 ... inner axis of inner tube, 133 ... one end of inner tube, 136 ... web, 137 ... flange, 138 ... chamfered part (chamfered part of fitting plate), A1 ... axial direction of steering shaft, C1 ... first Direction C2, second direction, L1, first predetermined distance, L2, second predetermined distance, L3, shock absorption stroke amount (shrinkage amount).

Claims (4)

A steering shaft coupled to the steering member;
A steering column that rotatably supports the steering shaft via a bearing; a cylindrical key lock collar that is fixed to the outer periphery of the steering shaft and has a key lock hole for engaging a lock pin for steering lock; With
The steering column includes an outer jacket and an inner jacket that are fitted together so as to be relatively movable in the axial direction of the steering shaft.
The outer jacket includes an outer tube surrounding the key lock collar,
The cross section of the outer tube has a relatively long shape in the first direction among the first and second directions orthogonal to each other, and a relatively short shape in the second direction.
The inner jacket includes a pair of an inner tube that is not fitted to the outer tube, and a groove-shaped or U-shaped cross-section that extends upward in the axial direction from one end of the inner tube and is fitted to the inner periphery of the outer tube. Including a mating plate,
The pair of fitting plates are opposed to each other in the first direction across the central axis of the inner tube,
When the vehicle collides, the pair of fitting plates move between the inner circumference of the outer tube and the outer circumference of the key lock collar as the outer jacket and the inner jacket move along the axial direction. An impact absorbing steering device for a vehicle, characterized in that it is inserted into the insertion space of the vehicle. In claim 1,
The outer tube has a rectangular cross section,
Each of the pair of fitting plates has a groove shape including a web and a pair of flanges, and each of the web and the pair of flanges is fitted to a corresponding flat surface element on the inner periphery of the outer tube. A shock absorbing steering device for a vehicle characterized by comprising: In claim 2,
A chamfer is provided at the corner of the cross section of the outer tube,
A vehicular impact absorbing steering apparatus, wherein a chamfered portion that fits into the chamfered portion of the outer tube is provided between the web and each of the flanges. In any one of Claims 1-3,
The bearing includes a bearing held by the outer jacket,
The inner tube and the key lock collar are opposed to each other at a first predetermined distance in the axial direction,
The bearing held by the outer jacket and each fitting plate are opposed to each other at a second predetermined distance in the axial direction,
The vehicular shock absorbing steering apparatus, wherein the first predetermined distance and the second predetermined distance are equal to each other, and regulate a contraction amount of the steering column at the time of a vehicle collision.

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