JP2006007934A - Steering device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a steering device capable of absorbing a shock with a simple structure irrespective of an operating condition. <P>SOLUTION: The steering device is equipped with a steering shaft 11 attaching a steering wheel in the axial direction, a steering column 12 rotatably storing and supporting the steering shaft 11, and a shock absorption mechanism absorbing the load applying to the steering shaft 11 in the axial direction. The shock absorption mechanism is equipped with a pressing member 20A pressing the steering column 12 from the outside, and a pressing force adjustment part 20B adjusting the pressing force of the pressing member 20A pressing the steering column 12. The pressing member 20A is equipped with a first wedge member 25 having a shape along the outer peripheral surface of the steering column 12, and a second wedge member 26 which is disposed on the tip end side of the bolt 24 and transmits the pressing force of the bolt 24 to the first wedge member 25. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a steering device.

  2. Description of the Related Art Conventionally, when an automobile collides with another automobile, a building, or the like, there is an impact absorption type steering apparatus provided with an energy absorbing apparatus that absorbs collision energy when a driver collides with a steering wheel due to the inertia of the collision. .

  In general, this type of shock-absorbing steering wheel device supports the steering column so that it can be moved forward by impact against the vehicle body, and absorbs collision energy by limiting the movement of the steering column during the movement. It is supposed to be.

By the way, when the driving conditions, for example, the driver is different, the weight of the driver is different from time to time, so that the load applied to the steering column changes, and there is a possibility that the impact energy cannot be absorbed sufficiently depending on each driver. For this reason, there is an impact absorption type steering device in which the amount of collision energy absorbed can be controlled according to driving conditions (see, for example, Patent Document 1). In this device, the rotation angle of the support pin is changed so that the support pin can control the amount of deformation of the energy absorption plate and adjust the amount of energy absorption.
Japanese Unexamined Patent Publication No. 2002-36281 (FIG. 4)

  However, in the steering device described in Patent Document 1, the rotation angle of the support pin is controlled by a motor. This motor overcomes the reaction force when the support pin squeezes the energy absorbing plate. Must be high torque. For this reason, there existed a problem that a motor will be enlarged and it will become expensive. Furthermore, a separate mechanism for restricting the rotation angle of the support pin is required, which further increases the size of the steering device.

  An object of the present invention is to provide an impact-absorbing steering device that has a simple structure and can absorb impacts regardless of driving conditions.

  In order to solve the above problems, the invention according to claim 1 is directed to a steering shaft on which a steering wheel is attached in an axial direction, a steering column that rotatably accommodates and supports the steering shaft, and the steering shaft. An impact absorbing mechanism that absorbs a load applied in an axial direction, wherein the impact absorbing mechanism includes a pressing member that presses the steering column from the outside, and a pressing force by which the pressing member presses the steering column. The gist of the present invention is to include a pressing force adjusting unit for adjusting the pressure.

  According to a second aspect of the present invention, in the steering apparatus according to the first aspect, the pressing force adjusting portion meshes with the worm driven by a drive source and the worm and is rotatable with respect to the steering column. The gist is provided with a supported worm wheel and a bolt supported so as to be rotatable integrally with the worm wheel and capable of moving forward and backward with respect to the pressing member.

  According to a third aspect of the present invention, in the steering device according to the second aspect, the first wedge member having a shape along the outer peripheral surface of the steering column and the front end side of the bolt are arranged to push the bolt. And a second wedge member that transmits pressure to the first wedge member.

  According to a fourth aspect of the present invention, in the steering device according to the second or third aspect, a load sensor that detects a load applied on the vehicle seat, and an optimum advance amount of the bolt based on the load are set. The gist of the present invention is to provide a control unit that drives the drive source so that the bolt is advanced by the advance amount.

  According to a fifth aspect of the present invention, in the steering apparatus according to the fourth aspect, the control unit includes a storage unit that stores a map in which the load detected by the load sensor is associated with the amount of advancement of the bolt. It is summarized as having.

(Function)
According to the first aspect of the present invention, the load applied to the steering shaft in the axial direction is absorbed by the pressing member that presses the steering column that rotatably accommodates and supports the steering shaft from the outside. That is, the pressing member slides on the outer peripheral surface of the steering column that moves in the axial direction on the steering shaft, and the impact force applied to the steering shaft is absorbed. For this reason, the impact absorbing mechanism can be formed integrally with the steering column, and the steering device can be miniaturized.

  Further, since the pressing force with which the pressing member presses the steering column is adjusted by the pressing force adjusting unit, the pressing member can be brought into sliding contact with the steering column with an appropriate pressing force according to the load applied to the steering shaft. It is possible to absorb shocks regardless of operating conditions.

  According to invention of Claim 2, a volt | bolt can be advanced / retreated with respect to a press member with a drive source, a worm | warm, and a worm wheel. For this reason, the pressing force of the pressing member against the steering column (steering shaft) can be set to an appropriate value by adjusting the advancement amount of the bolt with respect to the pressing member. Therefore, the shock absorbing mechanism can absorb shocks appropriately corresponding to the operating conditions.

  According to the third aspect of the present invention, the pressing force of the bolt against the second wedge member is converted and transmitted to the first wedge member that presses the outer peripheral surface of the steering column. For this reason, even if the pressing member is pressed from any direction, the steering column can be pressed from the outer peripheral surface. Therefore, the shock absorbing mechanism can be made compact.

  According to the fourth aspect of the present invention, when the load applied to the vehicle seat is detected by the load sensor, the control unit sets the optimum amount of advancement of the bolt based on the detected load, and the bolt is advanced. The drive source is driven so as to advance by the amount. For this reason, the amount of advancement of the bolt with respect to the pressing member, that is, the pressing force with which the pressing member presses the steering column is set by the load (operating condition) applied to the vehicle seat, and therefore, the appropriate amount corresponding to the load applied to the steering shaft. Value.

  According to the fifth aspect of the present invention, since the appropriate amount of advancement of the bolt is set by the control unit with respect to the load applied on the vehicle seat, the shock absorbing mechanism suitably absorbs the shock regardless of the operating conditions. It can be carried out.

  According to the present invention, it is possible to provide a steering device that can absorb shocks with a simple structure regardless of driving conditions.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, an embodiment of the invention will be described with reference to the drawings.
FIG. 1 is a schematic view inside a vehicle to which the steering device of this embodiment is applied. 2 is a plan view of the steering apparatus according to the present embodiment, FIG. 3 is a cross-sectional view taken along the line AA in FIG. 2, FIG. 4 is a cross-sectional view taken along the line BB in FIG. It is line sectional drawing. FIG. 6 is a block diagram for explaining the electrical configuration of the steering apparatus of the present embodiment.

  As shown in FIG. 1, the steering device 10 of the present embodiment includes a steering shaft 11 to which a steering wheel H is attached, a steering column 12 that rotatably accommodates and supports the steering shaft 11, and a shaft mounted on the steering shaft 11. And an impact absorbing mechanism 20 for absorbing a load applied in the direction. Note that one end side of the steering shaft 11 is connected to the steering wheel H, and the other end side is connected to the steering gear box via an intermediate shaft.

  As shown in FIG. 2, the steering column 12 includes a column tube 13 that supports the steering shaft 11 and a column housing 14 that supports the column tube 13. The steering device 10 is supported by a first bracket 15 in which the front (column housing 14) of the steering column 12 is fixed to the vehicle body, and the rear (column tube 13) of the steering column 12 is supported by the second bracket 16. Yes. The first bracket 15 includes a fixed portion 15a fixed to the vehicle body and a detachable portion 15b that can be detached from the fixed portion 15a. When the load is not applied to the steering shaft 11 from the steering wheel H side, the first bracket 15 supports the steering column 12 with the detachable portion 15b fixed to the fixing portion 15a, and the steering column 12 supports the front of the vehicle. When a predetermined load is applied toward, the detachment portion 15b is detached and moved forward. That is, the 1st bracket 15 is supporting the steering column 12 so that a breakaway is possible ahead.

  As shown in FIG. 3, the steering shaft 11 includes a first shaft 11a connected to the intermediate shaft and a second shaft 11b slidably fitted to the first shaft 11a. Splines are formed in portions where the first shaft 11a and the second shaft 11b are fitted, and the splines formed on the inner peripheral surface of the second shaft 11b are formed on the outer peripheral surface of the first shaft 11a. Meshed with the spline. For this reason, the second shaft 11b is slidable with respect to the first shaft 11a, is securely fixed to the first shaft 11a in a circumferential manner, and is integrally rotatable.

  The column tube 13 includes a first column tube 13a that is fixed to the vehicle body via the second bracket 16, and a second column tube that is slidably fitted in the axial direction on the inner peripheral surface of the first column tube 13a. 13b. Further, bearings 17a and 17b are attached to the first column tube 13a and the second column tube 13b of the column tube 13, and the steering shaft 11 is rotatable to the column tube 13 via the bearings 17a and 17b. It is supported so as not to move in the axial direction. Specifically, the first shaft 11a is supported via a bearing 17a at the end of the first column tube 13a, and the second shaft 11b is supported via a bearing 17b at the end of the second column tube 13b. It is supported. A column housing 14 fixed to the detaching portion 15b of the first bracket 15 is fixed to the outer peripheral surface of the first column tube 13a.

  That is, the steering wheel H, the column housing 14, the second column tube 13b, and the second shaft 11b are integrated with the first column tube 13a and the first shaft 11a fixed to the vehicle body via the second bracket 16. It is possible to move in the axial direction.

[Shock absorbing mechanism]
Here, the shock absorbing mechanism 20 will be described in detail.
4 and 5, the shock absorbing mechanism 20 includes a pressing member 20A that presses the steering column 12 from the outside, and a pressing force adjusting unit 20B that adjusts the pressing force by which the pressing member 20A presses the steering column 12. And.

  The pressing force adjusting unit 20B includes a worm 22 that is driven by a motor 21 as a drive source fixed to the column housing 14, a worm wheel 23 that meshes with the worm 22 and is rotatably supported by the column housing 14. , A bolt 24 that rotates integrally with the worm wheel 23 and is movable forward and backward with respect to the pressing member 20A is provided.

  The pressing member 20 </ b> A is disposed on the distal end side of the first wedge member 25 having a shape along the outer peripheral surface of the steering column 12 (first column tube 13 a) and the bolt 24. And a second wedge member 26 that transmits the first wedge member 25 to the first wedge member 25.

  A wall portion 14 a is provided in the column housing 14 in order to transmit the force that the bolt 24 presses the second wedge member 26 to the first wedge member 25. The second wedge member 26 is pressed toward the wall portion 14a and presses the first wedge member 25 by the reaction force of the pressing force against the wall portion 14a. In addition, the 2nd wedge member 26 is accommodated in the space which tapers toward the advancing direction of the volt | bolt 24 by the wall part 14a.

  When the motor 21 of the pressing force adjusting unit 20B is driven and the torque is transmitted to the bolt 24 via the worm 22 and the worm wheel 23, the bolt 24 is directed in the direction toward the pressing member 20A (second wedge member 26). Advancing and retreating along.

  When the bolt 24 advances a predetermined amount toward the second wedge member 26, the second wedge member 26 is pressed toward the traveling direction of the bolt 24, and the pressing force is applied to the first column tube 13a via the first wedge member 25. Is transmitted to the outer peripheral surface. At this time, since the second wedge member 26 is pressed toward the tapered space, it is efficiently formed between the first wedge member 25 (the outer peripheral surface of the first column tube 13a) and the wall portion 14a due to the wedge effect. It is pushed into the created space.

  A frictional force is generated between the first wedge member 25 and the first column tube 13a in accordance with the advancement amount of the bolt 24, that is, the pressing force of the bolt 24 against the second wedge member 26. By this frictional force, an impact load applied to the steering wheel H in the axial direction is absorbed.

  Further, as shown in FIG. 6, in the present embodiment, the shock absorbing mechanism 20 is connected to an ECU 18 as a control unit, and the ECU 18 has a load disposed below the vehicle seat S of the vehicle. A detection signal of the sensor 19 (see FIG. 1) is input. The ECU 18 receives the driver's load detected by the load sensor 19 and controls the shock absorbing mechanism 20 based on the detection signal.

  The ECU 18 controls the power amount (energization amount or rotation time) of the motor 21 constituting the shock absorbing mechanism 20 to adjust the advancement amount of the bolt 24, so that the first wedge member 25 and the second wedge member 26 become the first wedge member 26. The pressing force applied to the outer peripheral surface of the one column tube 13a is changed.

  The ECU 18 includes a memory 18a as a storage unit. The memory 18a includes a map 18b in which the load detected by the load sensor 19, that is, the driver's load, and the advance amount of the bolt 24 are associated with each other. It is remembered. The relationship between the driver's load and the amount of advance of the bolt 24 is obtained in advance by experiments, simulations, etc., and stored in the map 18b. Then, the ECU 18 sets the advancement amount of the bolt 24 by referring to this map 18b.

  The ECU 18 determines the amount of power supplied to the motor 21 based on the set advance amount of the bolt 24. Specifically, for example, the power amount is decreased as the driver's load is smaller, and the power amount is increased as the driver's load is larger. Then, the ECU 18 controls the operation of the bolt 24 by supplying the determined electric energy to the motor 21.

As described above in detail, according to the present embodiment, the following effects can be obtained.
(1) In this embodiment, the load applied to the steering shaft 11 in the axial direction is absorbed by the pressing member 20A that presses the steering column 12 that accommodates and supports the steering shaft 11 rotatably. That is, the pressing member 20A comes into sliding contact with the outer peripheral surface of the steering column 12 moving in the axial direction on the steering shaft 11, and the impact force applied to the steering shaft 11 is absorbed. For this reason, the shock absorbing mechanism 20 can be configured integrally with the steering column 12, and the steering device 10 can be downsized.

  (2) In the present embodiment, the pressing force with which the pressing member 20A presses the steering column 12 is adjusted by the pressing force adjusting unit 20B, and therefore the pressing member with an appropriate pressing force according to the load applied to the steering shaft 11 20A can be brought into sliding contact with the steering column 12, and the impact can be absorbed regardless of the driving conditions.

  (3) In the present embodiment, the motor 24, the worm 22 and the worm wheel 23 allow the bolt 24 to advance and retract with respect to the pressing member 20A. For this reason, the pressing force of the pressing member 20A against the steering column 12 (steering shaft 11) can be set to an appropriate value by adjusting the advancement amount of the bolt 24 with respect to the pressing member 20A. Therefore, the shock absorbing mechanism 20 can appropriately absorb the shock corresponding to the operating conditions.

  (4) In this embodiment, the pressing force of the bolt 24 against the second wedge member 26 is converted and transmitted to the first wedge member 25 that presses the outer peripheral surface of the steering column. For this reason, the pressing member 20 </ b> A can press the steering column 12 from the outer peripheral surface regardless of which direction is pressed. Therefore, the shock absorbing mechanism 20 can be made compact.

  (5) In the present embodiment, when the load applied on the vehicle seat S is detected by the load sensor 19, the ECU 18 sets an optimal advancement amount of the bolt 24 based on the detected load, and the bolt 24 is advanced. The motor 21 is driven so as to advance by the amount. For this reason, the advancing amount of the bolt 24 with respect to the pressing member 20A (second wedge member 26), that is, the pressing force with which the pressing member 20A presses the steering column 12 is set by the load (operating condition) applied to the vehicle seat S. Therefore, the value is appropriate for the load applied to the steering shaft 11.

  (6) In the present embodiment, since the appropriate advance amount of the bolt 24 is set for the load applied on the vehicle seat S by the ECU 18, the shock absorbing mechanism 20 suitably absorbs the shock regardless of the operating conditions. be able to.

In addition, you may change the said embodiment as follows.
-The drive source which drives the volt | bolt 24 is not limited to the motor 21, For example, you may use a solenoid. In this case, the bolt 24 may advance toward the second wedge member 26 when the solenoid is energized, and the bolt 24 may be retracted from the second wedge member 26 when the solenoid is not energized.

  The ECU 18 may control the motor 21 based on a previously input load regardless of the detection signal detected by the load sensor 19. Alternatively, the advancement amount of the bolt 24 may be set stepwise in advance and the operation may be selected in advance.

  The direction in which the bolt 24 presses the pressing member 20A, that is, the traveling direction of the bolt 24 relative to the second wedge member 26 is not limited, and may be a direction along the axial direction of the steering device 10 or a direction orthogonal to the coaxial direction. It is good.

  The pressing member that presses the steering column 12 from the outer peripheral surface is not necessarily limited to the first and second wedge members 25 and 26. As long as it is arranged on the outer peripheral surface of the column tube 12a and the pressing force to the steering column 12 is adjusted, it may be in any form.

  The manner in which the ECU 18 controls the drive of the motor 21 is not limited to the above embodiment. For example, the ECU 21 moves the bolt 21 toward the first wedge member 25 only when the driver's weight is heavy. It may be driven. In that case, the ECU 18 compares the load detected by the load sensor 19 with a preset threshold value of the load, and drives the motor 21 only when the detected load is larger than the threshold value.

  In the present invention, the predicted impact force is calculated based on signals from various sensors that detect the presence / absence of the driver's seat belt and the vehicle speed in addition to the load applied to the vehicle seat (when the vehicle is running) It is also possible to carry out in such a way that it is always calculated.

The technical idea that can be grasped from the above embodiment or another example will be described below.
(A) a second shaft that is slidably fitted to the first shaft, a column housing that is non-movably attached to the vehicle body, and through which the first shaft and the second shaft are inserted, and the column housing A column tube that slides in the axial direction together with the second shaft, a pressing member that presses the column tube from the outside, and a pressing force adjusting unit that adjusts the pressing force by which the pressing member presses the column tube A steering apparatus comprising:

Schematic which shows one Embodiment of this invention. The top view which shows the steering device of the embodiment. FIG. 3 is a cross-sectional view taken along line AA in FIG. 2. BB sectional drawing of FIG. The CC sectional view taken on the line of FIG. The block diagram explaining the electrical constitution of the embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Steering device, 11 ... Steering shaft, 12 ... Steering column, 13 ... Column tube, 14 ... Column housing, 18 ... ECU as control part, 18a ... Memory as memory | storage part, 18b ... Map, 19 ... Load sensor, DESCRIPTION OF SYMBOLS 20 ... Shock absorption mechanism, 20A ... Pressing member, 20B ... Pressing force adjustment part, 21 ... Motor as a drive source, 22 ... Worm, 23 ... Wheel, 24 ... Bolt, 25 ... 1st wedge member, 26 ... 2nd wedge Member, H ... steering wheel, S ... vehicle seat.

Claims (5)

A steering shaft on which the steering wheel is attached in the axial direction;
A steering column that rotatably accommodates and supports the steering shaft;
A steering device including an impact absorbing mechanism that absorbs a load applied to the steering shaft in an axial direction;
The shock absorbing mechanism is
A pressing member that presses the steering column from the outside;
A steering apparatus comprising: a pressing force adjusting unit that adjusts a pressing force with which the pressing member presses the steering column. The steering apparatus according to claim 1, wherein
The pressing force adjusting unit includes a worm driven by a driving source, a worm wheel that meshes with the worm, and is rotatably supported by the steering column, and can rotate integrally with the worm wheel; and A steering device comprising: a bolt supported so as to be capable of advancing and retreating with respect to the pressing member. The steering apparatus according to claim 2, wherein
A first wedge member having a shape along an outer peripheral surface of the steering column; and a second wedge member that is disposed on a tip end side of the bolt and transmits a pressing force of the bolt to the first wedge member. Steering device characterized. The steering apparatus according to claim 2 or 3,
A load sensor for detecting a load applied to the vehicle seat; and a controller for driving the drive source so as to set an optimum advance amount of the bolt based on the load and advance the bolt by the advance amount. A steering apparatus comprising: The steering apparatus according to claim 4, wherein
The steering device according to claim 1, wherein the control unit includes a storage unit that stores a map in which a load detected by the load sensor is associated with an advance amount of the bolt.

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