JP2009035104A - Steering device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a steering device capable of securing a collapse stroke even though the device is arranged with a key lock collar. <P>SOLUTION: The inside diameter ϕ1 of the key lock collar 112 is larger than the outside diameter ϕ2 of the end of an upper shaft 108. Therefore, when the upper shaft 108 relatively moves toward a lower shaft 110 at the time of a secondary collision, the upper shaft 108 sinks into the inside-diameter side of the key lock collar 112. Therefore, even if the key lock collar 112 is arranged at the lower shaft 110, a relative moving amount of the upper shaft 108 can be gained until it abuts to the end of the larger-diameter part 110b and the longer collapse stroke can be secured thereby. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an improvement in a steering column (especially an electric power steering), and relates to a steering apparatus that can secure a collapse stroke at the time of collision in a limited space and can absorb collision energy more appropriately.

  Combination switches, etc. are arranged around the steering column of the vehicle. Especially in the configuration in which the electric power steering device is incorporated in the steering column, a motor, a speed reducer, etc. are additionally provided, so that space The constraints are getting bigger. On the other hand, there is also a demand to increase the collapse stroke in the steering device as much as possible due to the increasing demand for safety.

Here, as shown in Patent Document 1, a steering device having a steering lock device is known. In such a steering device, when the ignition key is turned to the lock position and pulled out from the key hole, the lock key protrudes toward the axial center side of the steering shaft, and the key lock hole of the key lock collar fixed to the outer periphery of the steering shaft. The front end of the lock key is engaged to fix the steering shaft to the outer column so as to prevent the steering shaft from rotating.
JP 2006-264424 A

  Incidentally, in some steering apparatuses, the steering shaft has a two-part structure composed of an upper shaft and a lower shaft that is splined to the upper shaft. In such a steering device, when a force is applied to the steering wheel from the driver at the time of a secondary collision, the upper shaft and the lower shaft are relatively moved in the approaching direction to alleviate the impact. However, when the key lock collar is installed on the steering shaft divided into two parts, the installation position is limited due to the above-mentioned space restrictions, thereby preventing relative movement between the upper shaft and the lower shaft, and a large collapse stroke cannot be secured. There is a fear.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a steering device capable of ensuring a collapse stroke despite the provision of a key lock collar.

The steering device of the present invention is
A column member fixed to the vehicle body;
A first shaft rotatably supported with respect to the column member;
A second shaft that is axially movable with respect to the first shaft and is connected so as not to rotate relative to the first shaft;
A key lock collar disposed around one of the first shaft and the second shaft;
When the first shaft and the second shaft move relative to each other in the axial direction, the other shaft penetrates radially inward of the key lock collar.

  According to the present invention, when the first shaft and the second shaft move relative to each other in the axial direction, the other shaft enters inward in the radial direction of the key lock collar. The collar does not hinder the relative movement between the first shaft and the second shaft, and can ensure a collapse stroke.

  The one shaft and the key lock collar are preferably splined.

  It is preferable that a tolerance ring is disposed between the one shaft and the key lock collar. The tolerance ring refers to a ring that is interposed between the shaft and the key lock collar and has a function of suppressing the relative rotation of the two below the allowable torque.

  When the other shaft moves relative to the one shaft, it is preferable to abut against the tolerance ring because the impact force when the shaft is attached to the bottom can be reduced.

  It is preferable that an elastic body is disposed between the one shaft and the key lock collar because an impact force when the shaft is attached to the bottom can be reduced.

  It is preferably incorporated in a column type electric power steering apparatus.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram of a column type electric power steering apparatus 100 according to the present embodiment. FIG. 2 is a partial side sectional view of the electric power steering apparatus 100.

  1 and 2, the housing 101 connects a cylindrical outer column 102. The housing 101 is attached to a vehicle body (not shown) by a lower bracket 103, and the outer column 102 is attached to the vehicle body (not shown) by an upper bracket 104. The housing 101 and the outer column 102 can be pivoted in the tilt direction about the axis (the pivot point O) of the bolt 105 that fixes the lower bracket 103 and the housing 101, and the operation lever L is operated. Thus, the outer column 102 is fixed to the upper bracket 104 at an arbitrary tilt position.

  A cylindrical inner column 106 is attached so as to be fitted to the outer column 102. Both columns are connected by a resin pin 107 fitted into the outer hole 106a of the inner column 106 from the peripheral hole 102a of the outer column 102 and the fitting of the outer column 102 and the inner column 106. The pin 107 is broken at the time of the secondary collision, and allows the inner column 106 to move relative to the outer column 102 in the axial direction.

  1 and 2, the upper shaft 108 to which a steering wheel (not shown) is attached at the right end is hollow and extends into the inner column 106 and the outer column 102. The shaft is positioned in the axial direction and is rotatably supported. A female spline 108a (see FIG. 3) is formed on the inner periphery of the upper shaft 108, and a male spline 110a (see FIG. 3) faces the outer periphery of the lower shaft 110 disposed coaxially in the outer column 102. The two are connected to each other so that they can move relative to each other in the axial direction at the time of collision by spline coupling but cannot rotate relative to each other. The outer column 102 and the inner column 106 constitute a column member, and the upper shaft 108 and the lower shaft 110 constitute a steering shaft. The column member and the steering shaft according to the present embodiment are contracted when receiving a large load in the axial direction during a secondary collision or the like. Note that, when the inner column 106 moves relative to the outer column 102, a resistance is applied to absorb the collision energy, but an energy absorbing mechanism that provides the function is not shown here.

  FIG. 3 is a diagram showing the steering shaft in an exploded state. In FIG. 3, a tolerance ring 111 is arranged between the outer peripheral surface of the large-diameter portion 110 b of the solid lower shaft 110 and the inner periphery of the key lock collar 112. Therefore, when the key lock collar 112 is fitted to the large diameter portion 110b, the tolerance ring 111 applies a predetermined frictional force, so that the key lock collar 112 is attached to the lower shaft 110 in a relatively non-rotatable manner. Become. The key lock collar 112 has a cylindrical shape and is formed with a notch 112a into which the key enters the outer periphery. The lock shaft (not shown) can be advanced and retracted by a key lock device provided in the outer column 102 (FIGS. 1 and 2). By engaging with the notch 112a, the rotation of the steering shaft and the steering wheel is prevented, thereby preventing theft. The lock shaft is retracted from the notch 112a of the key lock collar 112, so that the rotation of the steering shaft and the steering wheel is allowed and the vehicle is ready for driving. A dustproof seal S is disposed between the key lock collar 112 and the housing 101.

  FIG. 4A is a cross-sectional view showing the periphery of the steering shaft according to the present embodiment, and FIG. 4B is a side view of the tolerance ring used in the present embodiment. In this modification, the large-diameter portion 110 b of the lower shaft 110 has a cylindrical surface, and a tolerance ring 111 is disposed between this and the key lock collar 112. The tolerance ring 111 has a large number of convex portions 111a on the outer peripheral surface, and by adjusting the contact area thereof, relative rotation between the large-diameter portion 110b and the key lock collar 112 is disabled at an allowable torque or less. In the electromagnetic key lock mechanism, the key lock collar 112 may be required to rotate relative to the lower shaft 110 when a torque of about 200 Nm is applied, but a tolerance ring 111 is provided. Thus, the relative rotation of the two can be allowed.

  1 and 2, the output shaft 113 connected to the lower shaft 110 via the torsion bar 120 is connected to a steering mechanism (not shown) for steering the wheels via a universal joint (not shown). Although not described in detail, in the present embodiment, torque applied to the steering shaft via a steering wheel (not shown) is detected by the torque sensor 114, and further, based on a signal such as the vehicle speed, The ECU accommodated in the motor outputs an appropriate drive signal to the motor 115. The rotational force output from the motor 115 is decelerated by a worm wheel mechanism or the like (including the worm wheel 116 in FIGS. 5 and 7) in the housing 101, and is transmitted to the output shaft 113 as a steering assist force. .

  Next, the operation of the present embodiment will be described. FIG. 5 is a partial cross-sectional side view of the electric power steering apparatus 100 showing a state immediately after a steering wheel (not shown) is pushed by the driver's body at the time of a secondary collision, and FIG. FIG. 7 is a partial cross-sectional side view of the electric power steering apparatus 100 showing a state in which the electric power steering apparatus 100 moves relative to the lower shaft 110 and has a bottom, and FIG. 7 shows a state (a) shown in FIG. 5 and a state (b) shown in FIG. FIG. 3 is a cross-sectional view showing the periphery of the steering shaft in comparison.

  As shown in FIG. 7, the inner diameter φ1 of the key lock collar 112 is larger than the outer diameter φ2 of the end portion of the upper shaft 108. Therefore, when the upper shaft 108 moves relative to the lower shaft 110 at the time of a secondary collision, the upper shaft 108 enters the inner diameter side of the key lock collar 112. Therefore, even if the key lock collar 112 is provided on the lower shaft 110, as shown in FIG. 7B, the relative movement amount of the upper shaft 108 can be earned until it hits the shoulder of the large diameter portion 110b. By this, the collapse stroke CS can be secured for a long time. During operation, the lock key (not shown) is retracted outward in the radial direction of the outer column 102 and thus does not interfere with the upper shaft 108.

  FIG. 8A is a cross-sectional view showing the periphery of a steering shaft according to a modified example of the present embodiment, and FIG. 8B is a perspective view of a key lock collar used in the modified example. The key lock collar 112 ′ shown in FIG. 8B is preferably used for a key lock mechanism that electromagnetically locks, and grooves 112 c are formed at equal intervals on the outer periphery. Such a plurality of grooves 112c can be formed by cold forging. In the present embodiment, the overall length of the tolerance ring 111 is shorter than the overall length in the axial direction of the large diameter portion 110b. Therefore, when assembled to the lower shaft 110, the end of the tolerance ring 111 has a large diameter. It does not protrude from the portion 110b.

  Further, in the present modification, an O-ring 117 as an elastic body is disposed adjacent to the large diameter portion 110b in the gap between the key lock collar 112 'and the lower shaft 110. Depending on the specifications of the vehicle, it is required to moderate the rise of the impact force at the bottom. This can be dealt with, for example, by gently forming the end portion of the large-diameter portion 110b with which the upper shaft 108 abuts into a tapered shape. On the other hand, according to this modification, the upper shaft 108 comes into contact with the end of the large-diameter portion 110b through the O-ring 117. The rise of impact force when bottoming out can be moderated. Further, since the O-ring 117 is disposed in a sealed space, there is no possibility of dropping off. About another structure, it is the same as that of embodiment mentioned above.

  As another modification, when the tolerance ring 111 is assembled to the lower shaft 110 by making the entire length of the tolerance ring 111 longer than the overall length of the large diameter portion 110b in the axial direction, A configuration that protrudes into a cylindrical shape from 110b and protrudes into a gap between the key lock collar 112 and the lower shaft 110 is also conceivable. This protruding portion becomes an elastic body instead of the O-ring. According to such a modification, before the upper shaft 108 hits the end of the large-diameter portion 110 b, the impact energy is absorbed by crushing the protruding end of the tolerance ring 111, and the upper shaft 108 is against the lower shaft 110. The rise of impact force when bottoming out can be moderated. Therefore, the burden on a member (not shown) that inherently absorbs impact energy can be reduced, so that the steering device can be made compact. Furthermore, it is possible to save the trouble of assembling.

  FIG. 9A is a cross-sectional view showing the periphery of a steering shaft according to another modification, FIG. 9B is a side view of the tolerance ring used in this modification, and FIG. FIG. 5 is a perspective view of a tolerance ring used in this modification. In the present modification, the end of the tolerance ring 111 ′ has a tapered shape that is bent inward in the radial direction with respect to the above-described modification. According to the modification, the protruding end portion of the tolerance ring 111 is always crushed inward before the upper shaft 108 hits the end portion of the large-diameter portion 110b. The rise of the impact force at the time of bottoming can be made gentle while stabilizing.

  FIG. 10 is a diagram showing an example of a key lock collar that is preferably used in a key lock mechanism that mechanically locks. The key lock collar may have a notch (or a groove with a bottom on the inner diameter side) 112a as shown in FIG. 10 (a). However, as shown in FIG. 10 (b), the key lock collar penetrates to the inner diameter side. The elongated hole 112b can also be formed. In particular, the long hole 112b of the key lock collar 112 ″ shown in FIG. 10B can be formed at low cost by stamping or milling with a press.

  FIG. 11 is an exploded view of the steering shaft according to the modification. In this modification, a male spline 110c is formed on the outer periphery of the large-diameter portion 110b of the solid lower shaft 110, and a corresponding female spline (not shown) is formed on the inner periphery of the key lock collar 112. Is formed. Therefore, when the key lock collar 112 is fitted to the large diameter portion 110b, the key lock collar 112 is attached to the lower shaft 110 so as not to be relatively rotatable by spline coupling.

  The present invention has been described above with reference to the embodiments. However, the present invention should not be construed as being limited to the above-described embodiments, and can be modified or improved as appropriate.

1 is a schematic view of a column type electric power steering apparatus 100 according to the present embodiment. 1 is a partial cross-sectional side view of an electric power steering apparatus 100. FIG. It is a figure shown in the state which disassembled the steering shaft. FIG. 4 is a partial side sectional view of the electric power steering apparatus 100 showing a state immediately after a steering wheel (not shown) is pushed by a driver's body at the time of a secondary collision. FIG. 3 is a partial side sectional view of the electric power steering apparatus 100 showing a state in which the upper shaft 108 moves relative to the lower shaft 110 and has a bottom. FIG. 6 is a cross-sectional view showing the periphery of a steering shaft in a state (a) shown in FIG. 4 and a state (b) shown in FIG. 5 in comparison. FIG. 7A is a cross-sectional view showing the periphery of a steering shaft according to a modified example of the present embodiment, and FIG. 7B is a perspective view of a key lock collar used in the modified example. FIG. 8A is a cross-sectional view showing the periphery of a steering shaft according to another modification, and FIG. 8B is a side view of a tolerance ring used in this modification. FIG. 9A is a cross-sectional view showing the periphery of a steering shaft according to another modification, FIG. 9B is a side view of the tolerance ring used in this modification, and FIG. FIG. 5 is a perspective view of a tolerance ring used in this modification. It is a figure which shows the modification of a key lock color. It is a figure shown in the state which decomposed | disassembled the steering shaft concerning a modification.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Electric power steering apparatus 101 Housing 102 Outer column 102a Circumferential hole 103 Lower bracket 104 Upper bracket 105 Bolt 106 Inner column 106a Peripheral hole 107 Pin 108 Upper shaft 109 Bearing 110 Lower shaft 110b Large diameter part 111, 111 'Tolerance ring 112 Key Lock collar 112a Notch 112b Long hole 112c Groove 113 Output shaft 114 Torque sensor 115 Motor 116 Worm wheel 117 O-ring L Operation lever S Seal

Claims (6)

A column member fixed to the vehicle body;
A first shaft rotatably supported with respect to the column member;
A second shaft that is axially movable with respect to the first shaft and is connected so as not to rotate relative to the first shaft;
A key lock collar disposed around one of the first shaft and the second shaft;
The steering apparatus according to claim 1, wherein when the first shaft and the second shaft are relatively moved in the axial direction, the other shaft enters inward in the radial direction of the key lock collar.   The steering apparatus according to claim 1, wherein the one shaft and the key lock collar are spline-coupled.   The steering apparatus according to claim 1, wherein a tolerance ring is disposed between the one shaft and the key lock collar.   The steering apparatus according to claim 3, wherein when the other shaft moves relative to the one shaft, the steering device abuts on the tolerance ring.   The steering device according to any one of claims 1 to 4, wherein an elastic body is disposed between the one shaft and the key lock collar.   The steering apparatus according to any one of claims 1 to 5, wherein the steering apparatus is incorporated in a column type electric power steering apparatus.

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