The present invention relates to an electric steering apparatus.
in the related art, it is know that a steering apparatus for a vehicle includes an electric or manual tilt mechanism or telescopic mechanism such that a position of a steering wheel can be changed in accordance with the physique or posture of a driver.
For example, an electric steering apparatus 1 shown in
An actuator of the telescopic mechanism 20 includes a motor 21, a screw shaft 22 that is rotationally driven by the motor 21, and a nut 23 to be screwed to the screw shaft 22. The motor 21 is fixed to one end of the outer jacket 13, and the nut 23 is coupled to a protruding portion 15 that protrudes in a radial direction from a vehicle front side end portion of the inner jacket 14 that is opposite to the steering wheel 2. The protruding portion 15 of the inner jacket 14 protrudes outward from the outer jacket 13 through a long hole 16 provided in a side surface of the outer jacket 13.
As shown in
However, in the relate-art electric steering apparatus 1, it is necessary to provide the large slot-shaped long hole 16 in the side surface of the outer jacket 13, and therefore, there is a problem that the bending rigidity of the steering jacket 4 is reduced, and there is room for improvement. Further, in order to increase the stroke of the telescopic mechanism 20, it is necessary to dispose the motor 21 so as to protrude further toward the vehicle front side than a front end portion of the outer jacket 13, and as a result, there is a problem in layout that the entire length of the steering jacket 4 is increased.
In view of the above-described issues, an object of the present invention is to provide an electric steering apparatus including a telescopic mechanism capable of ensuring rigidity without providing a long hole in a side surface of a steering jacket,
According to an aspect of the present invention, there is provided an electric steering apparatus that includes; a top bracket attached to a vehicle body; a steering shaft to which a steering wheel is connected; a steering jacket held by the top bracket and configured to rotatably support the steering shaft on an inner side; and an actuator configured to adjust lengths of the steering shaft and the steering jacket. The steering jacket includes a first jacket member and a second jacket member in this order from a side proximal to the steering wheel, and the first jacket member and the second jacket member overlap each other such that the steering jacket is extendable and retractable in an axial direction. The actuator is connected to an extension bracket that is attached to an outer surface of the first jacket member and extends toward the front of the vehicle body, so as to extend and retract the first jacket member with respect to the second jacket member.
According to the present invention, the telescopic mechanism can be configured while ensuring the rigidity of the steering jacket without providing a long hole in the side surface of the steering jacket.
Hereinafter, embodiments of an electric steering apparatus according to the present invention will be described in detail with reference to the drawings.
In the present specification, the terms “front” and “rear” respectively refer to the front and rear of an electric steering apparatus with electric steering apparatus attached to a vehicle body, and the term “axial direction” refers to a direction along an axis of a steering shaft.
In the present embodiment, a telescopic mechanism that adjusts a position of a steering wheel in the axial direction will be mainly described, and the description of a tilt mechanism that adjusts a position of the steering wheel in an upper-lower direction will be omitted or simplified.
As shown in
The steering shaft 110 includes a first shaft member 111 and a second shaft member 112 in this order from the steering wheel 101 side. The first shaft member 111 and the second shaft member 112 overlap each other so as to be able to transmit rotation to each other by serration fitting or the like and to be able to extend and retract in an axial direction. Specifically, the steering wheel 101 is connected to the first shaft member 111, and the second shaft member 112 is fitted into a front end portion of the first shaft member 111 so as to be extendable and retractable with respect to the first shaft member 111.
it is preferable that the first shaft member 111 and the second shaft member 112 have a structure that cannot be mechanically separated from each other when the steering shaft 110 extends and retracts. Specifically, this structure is implemented by coupling the shaft members with a stopper provided between the shaft members, or a stopper provided in another component (for example, a jacket member) whose position in the axial direction is determined.
The steering jacket 120 includes a first jacket member 121 and a second jacket member 122 around the steering shaft 110 in this order from the steering wheel 101 side. The first and second jacket members 121 and 122 are coaxially arranged and overlap each other so that the steering jacket 120 can extend and retract in the axial direction. An outer diameter of the first jacket member 121 is smaller than an inner diameter of the second jacket member 122. Therefore, the first jacket member 121 is accommodated in the second jacket member 122 in an extendable and retractable manner.
It is preferable that the first jacket member 121 and the second jacket member 122 have a structure that cannot be mechanically separated from each other when the steering jacket 120 extends and retracts. Specifically, this structure is implemented by coupling the jacket members with a jacket shape such as an outward or inward protrusion constituting a stopper between the jacket members, or a stopper provided in another component (for example, an actuator or an actuator nut) having a specified stroke.
An extension bracket 125 that protrudes outward in the radial direction from an end portion on the steering wheel side and extends toward the front of the vehicle body (left direction in the drawing) along the outer periphery on an outer side in the radial direction of the second jacket member 122 is provided on an outer peripheral side of the first jacket member 121. That is, the extension bracket 125 is provided on an outer peripheral surface of the first jacket member 121 on the steering wheel side, and is coupled to a bracket support portion 125e that protrudes outward in the radial direction than an outer peripheral surface of the second jacket member 122.
A portion of the second jacket member 122 on a vehicle front side is coupled to ta front support portion 103a of the top bracket 103 such that the steering jacket 120 is rotatable about a pivot P0. The first jacket member 121 rotatably supports the first shaft member 111 by a pair of built-in bearings 114, 114, Further, the second jacket member 122 rotatably supports the second shaft member 112 by a built-in bearing 115. That is, the steering jacket 120 rotatably supports the steering shaft 110 by the bearings 114, 114, and 115 hued therein,
A universal coupling 161 is disposed at a front end portion of the second shaft member 112 so that the steering shaft 110 can be smoothly bent at the time of tilting. Therefore, as shown in
In addition, it is preferable that a rotation center O of the universal coupling 161 is set at the same position as or a position close to the pivot P0 which is a center point at which the steering jacket 120 rotates at the time of tilting. As the universal coupling 161, a universal joint, a flexible coupling, a rubber shaft joint, a block universal joint, a claw coupling, an elastic coupling, or the like can be used.
The telescopic actuator 130 is implemented by a screw shaft rotary actuator including a motor 133, a screw shaft 134 that is rotationally driven by the motor 133, and a nut 135 that is a driven portion to be screwed to the screw shall 134. The motor 133 is rotatably connected to the top bracket 103 via a pivot P1, and the nut 135 with which the screw shaft 134 is screwed is coupled to an end portion 125a of the extension bracket 125 on the vehicle front side via a pivot P2.
A speed reduction mechanism such as a worm/worm wheel mechanism may be provided between the motor 133 and the screw shaft 134.
The end portion 125a of the extension bracket 125 on the vehicle front side slidably contacts a guide portion 123 provided over the entire outer peripheral surface of the second jacket member 122 in the axial direction. As shown in
The end portion 125a of the extension bracket 125 is located rearward of a front end portion of the first jacket member 121.
Then, when the motor 133 of the telescopic actuator 130 is driven to rotate the screw shaft 134, as shown in
As described above, the extension bracket 125 is provided so as to protrude in the radial direction from the end portion on the steering wheel side and extend toward the front of the vehicle body (the left direction in the drawing) along the outer peripheral surface of the second jacket member 122, so that unlike the electric steering apparatus 1 in the related art shown in
Further, the end portion 125a of the extension bracket 125 is guided by the guide portion 123 of the second jacket member 122, so that the operation is stable even if the extension bracket 125 becomes long.
With this configuration, it is possible to use the screw shaft rotary actuator 130 which is inexpensive and has a small mechanism around the gear.
Further, by fixing the motor 113 to the top bracket 103 having high rigidity, the natural frequency of the steering jacket 120 can be increased to prevent resonance.
The fitted state between the end portion 125a of the extension bracket 125 and the guide portion 123 may be any one of the four forms shown in
For example, as shown in
As shown in
As shown in
Further, as shown in
In the present embodiment, the extension bracket 125 extends in the axial direction at a position offset from a straight line L connecting the pivot P1, which is a coupling point between the top bracket 103 and the motor 133, and the pivot P2, which is a coupling point between the nut 135 and the end portion 125a of the extension bracket 125.
As a result, when an excessive force in the axial direction acts on the electric steering apparatus 100 and a compressive force in the axial direction acts on the steering jacket 120 in a vehicle collision or the like, a radially outward (downward in the drawing) component force acts on the pivot P2, which is the coupling point between the nut 135 and the end portion 125a of the extension bracket 125, and the extension bracket 125 is deformed so as to move the pivot P2 radially outward. As a result, a deformation direction of the telescopic actuator 130 and the extension bracket 125 can be controlled.
For example, in an electric steering apparatus 100a according to a reference example shown in
Therefore, the extension bracket 125 preferably extends in the axial direction at a position offset from the straight line L connecting a coupling point P1 between the motor 133 of the actuator and the top bracket 103, and a coupling point P2 between the nut 135 of the actuator and the extension bracket 125.
The fitted shape between the end portion of the extension bracket and the guide portion may have a configuration as shown in
The end portion 125a of the extension bracket 125 is fitted to the guide portion 123 of the second jacket member 122, so that the movement of the extension bracket 125 in the direction orthogonal to the central axis CL of the electric steering apparatus 100 is restricted.
As in a modification of the first embodiment shown in
Although the breaking mechanism 140 is provided between the end portion 125a of the extension bracket 125 and the nut 135 in
In addition, a U-shaped fall prevention tool 126 that surrounds the screw shaft 134 of the telescopic actuator 130 from below is provided in a lower portion of the second jacket member 122. As a result, when the connection between the extension bracket 125 and the nut 135 is released and the screw shaft 134 is rotated about the pivot P1 in a clockwise direction in the drawing, the screw shaft 134 and the nut 135 are held by the fall prevention tool 126, so that it is possible to prevent the screw shaft 134 and the nut 135 from interfering with a leg of the driver or a surrounding device.
In addition, one of the nut bracket 136 and the end portion 125a of the extension bracket 125 may be provided with a load generating mechanism (not shown) that generates an absorption load of axial energy generated in the electric steering apparatus 100 at the time of a vehicle collision or the like. As the load generating mechanism, for example, a mechanism for curling and deforming a wire or a plate, a mechanism for tearing a plate, or a mechanism for generating a load by a frictional force can be used.
The deformation starting point may be a bent portion 145d that is bent so as to protrude upward (toward the first jacket member 121) at the substantially intermediate portion of the extension bracket 125 in the axial direction, as in an electric steering apparatus 100′ shown in
The present invention is not limited to the embodiments and the modifications described above, and modifications, improvements, and the like can be made as appropriate,
As described above, the present description discloses the following matters.
(1) An electric steering apparatus including:
According to this configuration, the telescopic mechanism can be configured while ensuring rigidity without providing a long hole in a side surface of the steering jacket.
(2) The electric steering apparatus according to claim 1,
According to this configuration, the stroke of the telescopic mechanism can be increased.
(3) The electric steering apparatus according to (1),
According to this configuration, the steering jacket can be extended and retracted while maintaining the rigidity of the steering jacket. Further, by fixing the motor to the top bracket having high rigidity, the natural frequency of the steering jacket can be increased to prevent resonance.
(4) The electric steering apparatus according to (1),
According to this configuration, the actuator is disposed without protruding toward the front of the vehicle, the stroke of the telescopic mechanism can be increased, and the degree of freedom of the shape of the top bracket can be increased.
(5) The electric steering apparatus according to any one of (1) to (4),
According to this configuration, a movement direction of the extension bracket can be stably guided by the guide portion.
(6) The electric steering apparatus according to (5),
According to this configuration, rotation and movement in the radial direction of the extension bracket can be prevented.
(7) The electric steering apparatus according to (1),
According to this configuration, at the time of a vehicle collision or the like, a force acting on the electric. steering apparatus can be released or absorbed to protect an occupant.
(8) The electric steering apparatus according to (1),
According to this configuration, at the time of a. vehicle collision or the like, the deformation direction of the extension bracket can he controlled to protect the occupant from the deformed extension bracket.
(9) The electric steering apparatus according to (1),
According to this configuration, a displacement direction of the actuator and the extension bracket can be controlled to protect the occupant.
(10) The electric steering apparatus according to (1),
According to this configuration, the steering shaft can be implemented by two shaft members including the first shaft member and second shaft member.
The present application is based on U.S. Provisional Patent Application No. 63/018,128 filed on Apr. 30, 2020, the contents of which are incorporated herein by reference.
Number | Date | Country | |
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63018128 | Apr 2020 | US |