JP2020104608A - Steering device - Google Patents

Abstract

To attain arbitrary adjustment of a dynamic friction force generated upon occurrence of secondary collision.SOLUTION: The steering device includes: a column tube 120 directly or indirectly connected with a steering member; a belt-like recessed part 122 provided on an outer-peripheral surface of the column tube 120 and extending in an axial direction of the column tube 120; and an annular first impact absorption body 150 provided on the outer-peripheral surface having protrusion parts in contact with the outer-peripheral surface of the column tube 120 on an extension of the recessed part 122 in a longitudinal direction and fitted onto the column tube 120. Upon occurrence of secondary collision, the column tube 120 and the first impact absorption body 150 relatively move with the recessed part 122 and the protrusion part that are radially overlapped with each other.SELECTED DRAWING: Figure 4

Description

The present invention relates to a steering device that steers a vehicle or the like.

BACKGROUND ART Conventionally, there is known a steering device including a column tube that rotatably holds a column shaft to which a steering member is connected, and a housing that holds the column tube slidably and is fixed to a vehicle (for example, Patent Document). Reference 1). Such a steering device has a shock absorbing mechanism that absorbs a shock by converting the force of the column tube immersing into the housing into friction during a secondary collision caused by a vehicle collision. This impact absorbing mechanism absorbs the impact at the time of a secondary collision to protect the steering operator.

JP, 2008-127062, A

In a steering device having a plurality of locations where dynamic friction is generated to absorb impact, the structure of the steering device is arranged so that dynamic friction occurs in the order in which each location begins to move in sequence and the impact can be absorbed in a desired profile. Designed. However, the inventor has found that dynamic friction may not occur in the order as designed at the time of a secondary collision. Further, it is one of the problems to generate a dynamic frictional force as designed without being affected by a manufacturing error.

The present invention has been made in view of the above-mentioned findings, and an object of the present invention is to provide a steering device capable of performing shock absorption with a dynamic friction force in a desired order and as designed during a secondary collision.

In order to achieve the above object, a steering device according to one aspect of the present invention is provided with a rod-shaped member to which a steering member is directly or indirectly connected, and a shaft provided on the outer peripheral surface of the rod-shaped member. A ring-shaped first shock absorber that has a strip-shaped recess extending in the direction, and a protrusion that contacts the outer peripheral surface of the rod-shaped member on the extension of the recess in the longitudinal direction, and is fitted to the rod-shaped member. When a secondary collision occurs, the rod-shaped member and the first shock absorber move relative to each other in a state where the recess and the protrusion overlap in the radial direction.

According to the present invention, it is possible to operate the first shock absorber in a desired order (profile), generate a desired dynamic frictional force, and perform shock absorption.

FIG. 1 is a perspective view showing a configuration of a steering device according to an embodiment of the present invention. FIG. 2 is a cross-sectional view showing the steering device in a cross section taken along the line I-I in FIG. 1. FIG. 3 is a plan view showing the first shock absorber and the cross section of the column tube. FIG. 4 is a perspective view showing the vicinity of the first shock absorber and the recess of the steering device. FIG. 5: is sectional drawing which shows the modification of a rod-shaped member. FIG. 6 is a plan view showing another example of the first shock absorber together with the cross section of the column tube.

Embodiments of a steering device according to the present invention will be described below with reference to the drawings. It should be noted that each of the embodiments described below shows a comprehensive or specific example. Numerical values, shapes, materials, constituent elements, arrangement positions and connection forms of constituent elements, steps, order of steps, and the like shown in the following embodiments are examples, and are not intended to limit the present invention. Further, among the constituent elements in the following embodiments, constituent elements not described in the independent claim showing the highest concept are described as arbitrary constituent elements.

In addition, the drawings are schematic diagrams in which the present invention is appropriately emphasized or omitted and ratios are adjusted, and may differ from actual shapes, positional relationships, and ratios.

FIG. 1 is a perspective view showing a configuration of a steering device according to an embodiment of the present invention. FIG. 2 is a cross-sectional view showing the steering device in a cross section taken along the line I-I in FIG. 1. As shown in these drawings, the steering device 100 is a device that steers the steered wheels of a vehicle in conjunction with steering by a steering operator, and includes a column shaft 110 and a column tube 120 that is one of rod-shaped members. A housing 130, a fastening means 140, and a first shock absorber 150. Although the steering device 100 includes a shaft member such as an intermediate shaft connected to the column shaft 110 and a steering mechanism such as a rack and pinion mechanism, the illustration and description thereof are omitted.

In normal use in which no collision has occurred, the steering device 100 loosens the tightening means 140 and slides the column tube 120 in the axial direction (Y-axis direction in the drawing) with respect to the housing 130, so that The changed position of the column tube 120 can be fixed by changing the position of the steering member according to the physique and tightening the housing 130 with the tightening means 140. In the case of the present embodiment, the steering device 100 can change the inclination of the housing 130 with respect to the vehicle body, and can also fix and release the inclination of the housing 130 by the tightening means 140.

The column shaft 110 is a member to which a steering member to be steered by a technician is attached to a tip end portion thereof, and is rotatably held inside the housing 130 via a column tube 120 so as to rotate the steering angle of the steering member. It is a member that transmits to the rudder mechanism. In the case of the present embodiment, the column shaft 110 is held by the column tube 120 via the first bearing 111, and is fixed to the column tube 120 in the axial direction and rotatable in the circumferential direction. The column shaft 110 is configured to expand and contract as the column tube 120 appears in and out of the housing 130, and to maintain transmission of the steering angle. Specifically, for example, the column shaft 110 includes a first shaft body 112 held by a first bearing 111 and a second shaft body (not shown) held by a housing via a second bearing (not shown). ing. The first shaft body 112 and the second shaft body are formed to realize a telescopic structure, and the first shaft body 112 appears and disappears with respect to the second shaft body as the column tube 120 appears and disappears with respect to the housing 130. Then, the column shaft 110 expands and contracts. Further, the first shaft body 112 and the second shaft body are formed so as to realize a spline fitting structure, and can transmit the steering angle of the steering member.

The column tube 120 is one of the embodiments of the rod-shaped member, and is a member called a column jacket or the like that rotatably holds the column shaft 110. The column tube 120 holds the steering member via the column shaft 110. Further, the column tube 120 is held by the housing 130 attached to the vehicle body, thereby disposing the steering member at a predetermined position via the column shaft 110. The shape of the column tube 120 is not particularly limited, but in the case of the present embodiment, it has a cylindrical shape (tubular shape) and is retained in an inserted state in a housing 130 having a through hole in the axial direction. In addition, the column tube 120 holds the column shaft 110 inwardly via a bearing such as the first bearing 111, and along with the held column shaft 110 with respect to the housing 130 in the axial direction (Y-axis direction in the drawing). It is movable.

A strip-shaped recess 122 is provided on the outer peripheral surface of the column tube 120. The recessed portion 122 extends in the axial direction of the column tube 120 (Y-axis direction in the drawing). The cross-sectional shape of the recess 122 that is perpendicular to the axial direction is not particularly limited, and may be a groove shape having a wall surface and a bottom surface that rise in the radial direction at both ends in the width direction. In the case of the present embodiment, the recessed portion 122 has a shape obtained by cutting a part of the outer peripheral surface of the column tube 120 with a surface perpendicular to the radial direction, and does not have a wall surface that rises in the width direction. The method for forming the recess 122 is arbitrary, but cutting is preferable because the shape of the recess 122 can be accurately and precisely controlled. The details of the recess 122 will be described later.

In the case of the present embodiment, the column tube 120 is formed with an elongated tube-shaped hole 121 extending in the axial direction and penetrating in the radial direction. A pin-shaped third shock absorber 135 that is pierced through the elongated tube hole 121 is fixed to the housing 130. The third shock absorber 135 is located inside the tube elongated hole 121 without hindering the movement of the column tube 120 with respect to the housing 130 during normal use. During normal use, the longitudinal edge of the tube elongated hole 121 comes into contact with the third shock absorber 135, thereby restricting the movement distance of the column tube 120 with respect to the housing 130 in the axial direction.

When the secondary collision occurs, the edge of the tube elongated hole 121 breaks the third shock absorber 135. The breakage of the third shock absorber 135 absorbs the shock of the secondary collision, and suppresses the shock given to the driver.

The housing 130 is a tubular member that holds the column tube 120 movably in the axial direction (Y-axis direction in the drawing) with respect to the vehicle body. Further, the housing 130 has a slit-shaped interference portion 132 (which extends axially through the peripheral wall in the radial direction (Z-axis direction in the drawing) at the end on the steering member side (rear side of the vehicle body) in the axial direction. (See FIG. 2) and the tightened portions 133 that respectively project from both sides of the tightening margin portion 132 in the radial direction. The tightened portion 133 is provided with through holes 134 that are orthogonal to the direction of penetration of the tightening margin portion 132 (one in the radial direction) and the axial direction of the column tube 120. A tightening shaft body 141 of the tightening means 140, which will be described later, is pierced through the through hole 134, and the interval between the two tightened parts 133 arranged in opposition to each other can be narrowed by the tightening means 140. .. By narrowing the interval between the tightened portions 133, the housing 130 clamps the pierced column tube 120 from the surroundings and holds it fixedly.

In the case of the present embodiment, a set of first hinge members 131 is provided in a protruding manner on the housing 130 at a portion opposite to the steering member (front side of the vehicle body) in the axial direction (Y-axis direction in the drawing). The housing 130 is tiltably fixed to the vehicle body by rotatably connecting the second hinge member (not shown) fixed to the vehicle body and the first hinge member 131 using the shaft body. .. Further, at the position on the steering member side (the rear side of the vehicle body) with respect to the first hinge member 131, two fixing brackets 170 are arranged symmetrically on both sides of the tightened portion 133. The fixed bracket 170 is a member fixed to the vehicle body. The two fixing brackets 170 are each provided with a fixed elongated hole 171 extending in the radial direction (tilt direction). The fixed elongated hole 171 may be formed in an arc shape around the rotation center of the first hinge member 131. The fixing bracket 170 is pressed against the tightened portion 133 of the housing 130 by the tightening means 140 pierced through the two fixed elongated holes 171, so that the housing 130 can be fixed at a predetermined tilt position. There is.

The tightening means 140 is a unit that positions the column tube 120 by tightening the radial end of the housing 130 outside the column tube 120. In the case of the present embodiment, the tightening means 140 is arranged such that the tightening means 140 is pierced through the through holes 134 of the tightened part 133 integrally extending on both sides of the tightening margin part 132 of the housing 130. The shaft 141 is provided. The tightening shaft body 141 includes a flange portion 142 that engages with the peripheral edge of the through hole 134 of the tightened portion 133 at one end. Further, the tightening means 140 includes a cam mechanism that can tighten and release the housing 130 on the side opposite to the flange portion 142 with respect to the tightening shaft body 141, and a tightening lever 143 that operates the cam mechanism. There is. The cam mechanism includes a fixed cam 144 fixedly attached to the housing 130 and a movable cam 145 attached to the tightening lever 143. By rotating the tightening lever 143, the movable cam 145 is attached to the fixed cam 144. By climbing up and the distance between the fixed cam 144 and the movable cam 145 is increased, the tightened portion 133 of the housing 130 is tightened.

In the case of the present embodiment, the fastening means 140 can press the fixing bracket 170 and the second shock absorber 160, which are arranged on the outer sides of the pair of fastened portions 133, respectively, to the fastened portion 133. It is possible. As described above, the tightening means 140 can operate the tightening lever 143 to reduce the distance between the pair of tightened portions 133, thereby allowing the housing 130 to tighten the column tube 120 for positioning. Further, the tightening means 140 can position the column tube 120 and press the two second shock absorbers 160 against the outer surfaces of the two tightened portions 133 of the housing 130 to generate a vertical reaction force. The second dynamic friction force at the time of the next collision can be generated. Further, the tightening means 140 positions the column tube 120 and fixes the second shock absorber 160 during normal use, and at the same time, presses the fixing bracket 170 against the tightened portion 133 via the second shock absorber 160. Thus, the tilt position of the housing 130 can be determined.

FIG. 3 is a plan view showing a cross section of the first shock absorber 150 and the column tube 120. FIG. 4 is a perspective view showing the vicinity of the first shock absorber of the steering device. As shown in these figures, the first shock absorber 150 is an annular member that is fixedly attached to the outer circumference of the column tube 120 in a contact state and moves together with the column tube 120 during normal use. Further, at the time of a secondary collision, the first shock absorber 150 slides relative to the column tube 120 and generates a first dynamic friction force for absorbing a shock with the column tube 120. The first shock absorber 150 includes a protrusion 153 that comes into contact with the outer peripheral surface of the column tube 120 when extending in the longitudinal direction (Y-axis direction in the drawing) of the recess 122 provided in the column tube 120.

It suffices that at least one protrusion 153 having the above-mentioned positional relationship is provided on the first shock absorber 150, and it is provided on a plurality of locations on the inner peripheral surface of the first shock absorber 150 at a predetermined distance. Good. In the case of the present embodiment, the first shock absorber 150 is provided with the protrusions 153 that are evenly arranged in the circumferential direction at six locations. Specifically, as shown in FIG. 4, the first shock absorber 150 has a rectangular plate-shaped base body 154 provided with a hole through which the column tube 120 is inserted, and a cylindrical portion 155 is formed at the periphery of the hole. It is provided so as to project in the axial direction. Further, the cylindrical portion 155 is provided with a protrusion 153 that projects toward the column tube 120 and extends in the axial direction, and the protrusion 153 and the outer surface of the column tube 120 are in surface contact with each other. By thus providing the first shock absorber 150 having the protrusion 153, the static friction coefficient and the dynamic friction coefficient are arbitrarily adjusted depending on the contact area between the protrusion 153 and the column tube 120 and the number of the protrusions 153. Therefore, the reproducibility and controllability of the maximum static friction force can be improved.

The relationship between the width (circumferential length) of the protrusion 153 on the extension of the recess 122 and the width of the recess 122 is not particularly limited, and the magnitude of the dynamic friction force generated at the time of the secondary collision. It is arbitrarily set by design based on. The distance between the recess 122 and the protrusion 153 in the axial direction, specifically, the distance between the end of the recess 122 on the vehicle front side and the end of the protrusion 153 on the steering member side in the axial direction is particularly limited. Although not limited to this, it is conceivable to open a distance equal to or greater than the depth of the recess 122 as one that is considered as one of the distances in which the recess 122 does not affect the maximum static friction force. Further, the width and the depth of the recess 122 may be constant in the axial direction, or a portion that gradually (including stepwise) changes may be provided in at least a part of the axial direction. Further, the recess 122 and the projection 153 arranged on the extension of the recess 122 may be one set, or a plurality of sets may be present.

The method of attaching the first shock absorber 150 to the column tube 120 is not particularly limited, but press fitting can be mentioned, for example. In addition, after the column tube 120 is pierced through the first shock absorber 150, the protrusion 153 may be pressed against the outer peripheral surface of the column tube 120 by partially caulking.

The second shock absorber 160 is a member that is fixedly connected to the tightened portion 133 of the housing 130 by the tightening force of the tightening means 140 during normal use. The second shock absorber 160 moves through the first shock absorber 150 that moves as the column tube 120 is retracted into the housing 130 due to the secondary collision, so that the second shock absorber 160 and the second tightening portion 133 are moved together. It is a member that generates a dynamic friction force.

In the case of the present embodiment, the second shock absorber 160 has a plate-shaped contact portion 163 that comes into planar contact with the outer surface of the tightened portion 133 of the housing 130 and an axial direction (Y-axis direction in the drawing). It is provided with a plate-shaped connecting portion 162 that is connected to the spreading contact portion 163 in a plane (XZ plane in the drawing) orthogonal to each other. The second shock absorber 160 is provided with a contact portion 163 and a connecting portion 162 outside the two tightened portions 133 in plane symmetry. The two connecting portions 162 are respectively connected to the base 154 of the first shock absorber 150, and the first shock absorber 150 and the second shock absorber 160 are integrated. Therefore, during normal use, when the tightening means 140 is unfastened, the second shock absorber 160 moves axially together with the column tube 120 via the first shock absorber 150. .. Further, the contact portion 163 is provided with a long hole portion 161 having a width capable of piercing the tightening shaft body 141 of the tightening means 140 and extending in the axial direction (Y-axis direction in the drawing). .. The contact portion 163 is pressed against the tightened portion 133 of the housing 130 by the tightening means 140 having the tightening shaft body 141 pierced through the long hole portion 161, and the second shock absorber 160 is fixed to the housing 130. .. In the case of the present embodiment, since the second shock absorber 160 is in a state of being sandwiched between the tightened portion 133 and the fixed bracket 170, a dynamic friction force is also generated between the second shock absorber 160 and the fixed bracket 170. .. The dynamic friction force may be included in the second dynamic friction force.

Next, the operation of the steering device 100 will be described.

During normal use, the operator operates the tightening lever 143 to release the tightening by the tightening means 140, whereby the housing 130 becomes rotatable around the first hinge member 131, and the column tube 120, The column shaft 110 is movable in the axial direction with respect to the housing 130. In such a state, the steering person sets the steering member to a position suitable for the steering person by moving the steering member up and down or forward and backward, and fixes the position set by the fastening means 140. While the tightening is released, the protrusion 153 on the extension of the recess 122 and the other protrusions 153 are in contact with the outer peripheral surface of the column tube 120 having a substantially perfect circle with a predetermined pressure. Since the maximum static friction force can be exerted, when the column tube 120 is pulled out of the housing 130, the first shock absorber 150 moves in the axial direction together with the column tube 120. The second shock absorber 160 moves together with the first shock absorber 150.

When a secondary collision occurs in which the driver collides with the steering member due to a vehicle collision, a strong force is generated in the direction in which the column tube 120 is retracted into the housing 130. Here, in the case of the present embodiment, since the profile for generating the first dynamic friction force by the first impact absorber 150 after the second dynamic friction force by the second impact absorber 160 is set, the first impact The maximum static frictional force between the absorber 150 and the column tube 120 is set to be larger than the maximum static frictional force between the second shock absorber 160 and the housing 130 tightened by the tightening means 140. Therefore, the second shock absorber 160 and the tightened portion 133 of the housing 130 first slip, and the second dynamic friction force is generated. The impact is absorbed by the second dynamic friction force. A dynamic frictional force is also generated between the housing 130 and the column tube 120, and the impact is also absorbed by this dynamic frictional force.

Next, when the column tube 120 further sinks into the housing 130, the axial end edge of the tube elongated hole 121 provided in the column tube 120 breaks the third shock absorber 135. The timing at which the first shock absorber 150 and the second shock absorber 160 slip and the third shock absorber 135 breaks occurs at the axial position of the steering member set immediately before the secondary collision. That is, it fluctuates according to the position of the column tube 120 with respect to the housing 130 set by the driver before the secondary collision. Specifically, for example, when the axial position of the steering member that is set immediately before the secondary collision is the position farthest from the operator in the telescopic adjustment range, the second shock absorber 160 slips and the third shock absorber is absorbed. The fractures of body 135 can occur at about the same time.

Next, while the first shock absorber 150 is stationary at the position according to the design with respect to the housing 130, the column tube 120 is further retracted into the housing 130, so that the first shock absorber 150 and the column tube 120 are separated from each other. During the period, a force equal to or larger than the maximum static friction force is generated, and the impact is absorbed by the first dynamic friction force smaller than the maximum static friction force.

Since the relationship between the first shock absorber 150 and the column tube 120 is set so that the maximum static friction force that satisfies the desired profile is obtained, the relationship between the first shock absorber 150 and the column tube 120 is maintained. When the state is changed to the state where the first dynamic friction force is generated, the first dynamic friction force may become too large. Therefore, the inventor has provided a band-shaped recess 122 extending in the axial direction on the outer peripheral surface of the column tube 120, and at least one of the protrusions 153 of the first shock absorber 150 that has moved beyond the maximum static friction force. The first dynamic frictional force can be reduced as designed by superimposing the groove on the recess 122.

As described above, even in the case where the maximum static friction force between the column tube 120 and the first shock absorber 150 is set higher in order to realize the order in which the dynamic friction force is generated according to the design value. It is possible to generate the first dynamic friction force with a profile as designed by adjusting the geometrical relationship between the protrusion 153 and the recess 122 and the number of pairs of the protrusion 153 and the recess 122. ..

The present invention is not limited to the above embodiment. For example, another embodiment realized by arbitrarily combining the constituent elements described in this specification or excluding some of the constituent elements may be an embodiment of the present invention. Further, the present invention also includes modified examples obtained by applying various modifications that those skilled in the art can think of to the above-described embodiment without departing from the gist of the present invention, that is, the scope of the wording described in the claims. Be done.

For example, although the cylindrical column tube 120 has been illustrated as the rod-shaped member, the rod-shaped member is not limited to the column tube 120, and the rod-shaped member to which the first shock absorber 150 is attached is arbitrary according to the structure of the steering device 100. To be selected. Further, the cross-sectional shape of the rod-shaped member perpendicular to the axial direction is not limited to a perfect circle, and an arbitrary shape such as a polygon can be adopted.

Further, in normal use in which a secondary collision does not occur, as shown in FIG. 5, the thickness D1 of the rod-shaped member 129 at the portion in contact with the protrusion 153 and the portion where the recessed portion 122 is arranged are shown. The thickness D2 may be different when at least a portion of the recessed portion 122 of the rod-shaped member 129 is absent (shown by a chain double-dashed line in the drawing). In the case of the example shown in FIG. 5, the thickness of the rod-shaped member 129 goes from the thickness D1 of the portion in contact with the protrusion 153 to the direction in which the recess 122 is arranged (the negative direction in the Y-axis direction in the figure). Gradually becoming thicker. In this way, the thickness of the rod-shaped member 129 into which the first impact absorber 150 is fitted is changed in the region where the first impact absorber 150 moves relative to the rod-shaped member 129 due to the secondary collision. Therefore, for example, when the first dynamic friction force is excessively reduced due to the recess 122, the first dynamic friction force can be increased by increasing the thickness of the rod-shaped member 129. Further, by making the rod-shaped member 129 thin, it is possible to reduce the first dynamic friction force.

Further, the protrusion 153 may be one as shown in FIG.

100: steering device, 110: column shaft, 111: first bearing, 112: first shaft body, 120: column tube, 121: tube elongated hole, 122: recessed portion, 129: rod-shaped member, 130: housing, 131: First hinge member, 132: Substitute part, 133: Tightened part, 134: Through hole, 135: Third shock absorber, 140: Tightening means, 141: Tightening shaft body, 142: Flange part, 143: Tightening lever, 144: Fixed cam, 145: Movable cam, 150: First shock absorber, 153: Projection, 154: Base, 155: Cylindrical part, 160: Second shock absorber, 161: Long hole part, 162: connection part, 163: contact part, 170: fixed bracket, 171: fixed elongated hole

Claims (4)

A rod-shaped member to which the steering member is directly or indirectly connected,
A strip-shaped recess provided on the outer peripheral surface of the rod-shaped member and extending in the axial direction of the rod-shaped member;
A protrusion that contacts the outer peripheral surface of the rod-shaped member on the extension of the recess in the longitudinal direction, and an annular first shock absorber fitted into the rod-shaped member,
A steering device in which, when a secondary collision occurs, the rod-shaped member and the first shock absorber move relative to each other in a state where the recessed portion and the protruding portion overlap in the radial direction. The steering device according to claim 1, wherein at least one of depth and width of the recess changes in the axial direction. The thickness of the rod-shaped member at a portion where the protrusion contacts is different from the thickness of the rod-shaped member at least in a portion where the recess is arranged, when the recess is absent. Steering device according to. The rod-shaped member is cylindrical,
A column shaft rotatably held inside the rod-shaped member,
A housing that holds the rod-shaped member pierced inward so as to be movable in the axial direction,
Clamping means for positioning the rod-shaped member by tightening so that a part of the housing in the axial direction is reduced in diameter outside the rod-shaped member,
The steering according to any one of claims 1 to 3, further comprising a second shock absorber that is fixedly connected to the housing by a tightening force of the tightening unit and that is connected to the first shock absorber. apparatus.

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