JP2011131723A - Steering device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a steering device that prevents generation of abnormal noise and also improves response. <P>SOLUTION: A steering angle ratio variable mechanism of the steering device includes a spring member 51 which presses a cam follower 23 to a bottom side in an axial direction. An outer peripheral surface 52 of the cam follower 23 and each sliding surface 53 of a cam groove 22 are each slantingly formed from an opening 22b side toward a bottom 22a side of the cam groove 22 so that pressing of the cam follower 23 by the spring member 51 may bring the respective surfaces 52 and 53 into contact with each other. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a vehicle steering apparatus.

  Conventionally, in a vehicle steering apparatus, for example, a first shaft connected to a steering wheel and a second shaft connected to a steered wheel are arranged eccentrically by a predetermined amount, and these shafts are rotated by a steering angle ratio variable mechanism. There is a configuration in which the relationship between the change in the steering angle and the change in the steering angle (steering angle) of the steered wheels becomes non-linear by connecting in a communicable manner (see, for example, Patent Document 1).

  Specifically, the steering angle ratio variable mechanism is connected to the first shaft so as to be integrally rotatable, and has a cam member having a U-shaped cam groove extending in a direction orthogonal to the axial direction of each shaft, And a cylindrical cam follower provided so as to be slidable, and an eccentric pin for connecting the second shaft and the cam follower at a position more eccentric than the predetermined amount from the second shaft. In such a rudder angle ratio variable mechanism, the rotation of the first shaft caused by the steering operation causes the eccentric pin (cam follower) to move first with the sliding of the cam follower in the cam groove and the rotation of the cam follower around the eccentric pin. By moving on two concentric circles, it is transmitted to the second axis. Thereby, depending on the position of the eccentric pin in the cam groove, the relationship between the change in the rotation angle of the first shaft caused by the steering operation and the change in the rotation angle of the second shaft that defines the change in the turning angle of the steered wheels, that is, The relationship between the change in the steering angle and the change in the steering angle of the steered wheels can be made nonlinear.

JP 2009-143429 A

  By the way, the cam follower is slidably inserted into the cam groove, and the outer dimension of the cam follower is the width of the cam groove (the axial direction of each axis and the length of the cam groove) in order to allow manufacturing tolerance of each component. (Length in the direction perpendicular to the direction)). Therefore, as shown in FIG. 8, a cam groove 74 is provided between the outer peripheral surface 73 of the cam follower 72 connected to the eccentric pin 71 and each sliding surface 75 that slides on the outer peripheral surface 73 in the cam groove 74. Is formed in the width direction (left and right direction in FIG. 8).

  Therefore, for example, when the cam member 76 starts to rotate together with the first shaft (not shown) by a steering operation, the outer peripheral surface 73 of the cam follower 72 and the sliding surface 75 of the cam groove 74 may collide and noise may be generated. There is. Further, since the change in the rotation angle of the first shaft is not transmitted to the second shaft until the outer peripheral surface 73 and the sliding surface 75 come into contact with each other, the response of the change in the steering angle of the steered wheels to the steering operation is improved. From the viewpoint, there was still room for improvement.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a steering device that can prevent the generation of abnormal noise and improve responsiveness.

  In order to achieve the above object, according to a first aspect of the present invention, there is provided a first shaft and a second shaft which are arranged eccentrically with each other by a predetermined amount, and the first shaft and the second shaft are coupled so as to be able to transmit rotation. A rudder angle ratio variable mechanism, the rudder angle ratio variable mechanism being connected to the first shaft and having a cam groove, a cam follower slidably provided in the cam groove, An eccentric pin that connects the second shaft and the cam follower, and the cam groove extends in a direction perpendicular to the axial direction of each axis and opens to the second shaft side, and the eccentric pin In a steering apparatus that connects the second shaft and the cam follower at a position that is more eccentric than the predetermined amount from the second shaft, the steering device includes a pressing unit that presses the cam follower, and the pressing unit includes the cam follower. The cam follower is pressed to the bottom side of the cam groove in the axial direction, and the cam follower is pressed by the pressing means on the outer peripheral surface of the cam follower and the outer peripheral surface of the cam groove. The gist is that the outer peripheral surface and the sliding surfaces are formed so as to be inclined from the opening side to the bottom side of the cam groove in the axial direction, respectively.

  According to the above configuration, since the cam follower is pressed by the pressing means and the outer peripheral surface and each sliding surface come into contact with each other, the backlash between them is reduced. For example, when the first shaft rotates by a steering operation The outer peripheral surface and the sliding surface do not collide, and it is possible to prevent the generation of abnormal noise. In addition, since the outer peripheral surface and each sliding surface are in contact with each other, the change in the rotation angle of the first shaft is quickly transmitted to the second shaft, and the responsiveness can be improved.

  Further, the force acting on the pressing means when the first shaft or the second shaft rotates is a fraction of the transmission force transmitted between the cam member and the cam follower according to the inclination of the outer peripheral surface and the sliding surface. Since it becomes force, the load which acts on a press means with steering operation can be restrained low. Furthermore, by inserting the cam follower and the eccentric pin into the cam groove along the axial direction, the rudder angle ratio variable mechanism can be assembled in a state in which the backlash is packed, so that its assemblability is good. Furthermore, since the pressing means presses the cam follower in the axial direction, the same pressing means can be used regardless of the size (outer diameter, etc.) of the cam follower, and cam followers having different sizes are employed. Parts can be shared between the steering angle ratio variable mechanisms, and the cost can be reduced.

  According to a second aspect of the present invention, in the steering apparatus according to the first aspect, the outer peripheral surface is a linear shape that tapers from the opening side to the bottom side of the cam groove as viewed in the longitudinal direction of the cam groove. The gist of the invention is that each sliding surface is formed in a straight line parallel to a portion of the outer peripheral surface in contact with each sliding surface as viewed in the longitudinal direction.

  According to the above configuration, since the outer peripheral surface of the cam follower and the sliding surfaces of the cam groove are in surface contact with each other, it is possible to suppress the pressure acting between them from being excessive. For example, the cam follower and the cam groove (cam member) It is possible to extend the service life.

  According to a third aspect of the present invention, in the steering device according to the first or second aspect, the eccentric pin is formed with a flange portion extending radially outward, and the pressing means includes the flange portion, the cam follower, and the like. The gist is that the elastic body is provided between the two.

  According to the above configuration, since the cam follower is pressed by the separately provided elastic body, for example, the shape of the eccentric pin can be simplified as compared with the case where the portion serving as the pressing means is integrally formed with the eccentric pin.

  According to a fourth aspect of the present invention, in the steering device according to the first or second aspect, the pressing means is an elastic flange portion that extends radially outward from the eccentric pin, and the elastic flange portion is The gist of the invention is that it is configured to be inclined toward the bottom side of the cam groove in the axial direction as it goes radially outward, and to be elastically deformable in the axial direction.

  According to the above configuration, since the cam follower is pressed by the elastic flange portion integrally formed with the eccentric pin, the number of parts can be reduced as compared with the case where an elastic body for pressing the cam follower is separately provided.

  According to a fifth aspect of the present invention, in the steering device according to the third or fourth aspect, the cam follower is formed with an insertion hole, and the cam follower has the eccentric pin inserted through the insertion hole. The eccentric pin is connected to be rotatable about the eccentric pin, and a regulating member is provided on the bottom side of the eccentric pin in the axial direction, and the regulating member is configured such that the cam follower has the axis line with respect to the eccentric pin. The gist is to restrict movement to the bottom side of the cam groove in the direction.

  According to the said structure, it can prevent that a cam follower falls off from an eccentric pin by a control member, and can aim at the improvement of an assembly | attachment property. In addition, the elastic member or the elastic flange can be elastically deformed by the restricting member before the steering angle ratio variable mechanism is assembled, and the load by which the cam follower is pressed in the axial direction by the pressing means can be easily set. it can.

  ADVANTAGE OF THE INVENTION According to this invention, the steering apparatus which can aim at the improvement of responsiveness while preventing generation | occurrence | production of unusual noise can be provided.

Sectional drawing of the steering column vicinity of a steering device. The expanded sectional view of the steering angle ratio variable mechanism vicinity. Action | operation explanatory drawing of the steering angle ratio variable mechanism using an eccentric pin. Sectional drawing orthogonal to the longitudinal direction of the cam groove of the eccentric pin vicinity of this embodiment. Sectional drawing orthogonal to the longitudinal direction of the cam groove of the eccentric pin vicinity in the state which the elastic body deform | transformed. Sectional drawing orthogonal to the longitudinal direction of the cam groove of another eccentric pin vicinity. Sectional drawing orthogonal to the longitudinal direction of the cam groove of another eccentric pin vicinity. Sectional drawing orthogonal to the longitudinal direction of the cam groove of the conventional eccentric pin vicinity.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, an embodiment of the invention will be described with reference to the drawings.
As shown in FIG. 1, in the steering device 1, the column shaft 4 constituting the steering shaft 3 with the steering 2 fixed to one end (the right end portion in the figure) has both end portions at the bearings 5a and 5b. By being pivotally supported, the steering column 6 is rotatably accommodated. The other end of the column shaft 4 (the left end portion in the figure) is an output shaft arranged eccentrically by a predetermined amount in the radial direction from the axis L1 of the column shaft 4 via the steering angle ratio variable mechanism 7. It is connected to one end of 8 so that rotation transmission is possible. The other end of the output shaft 8 is connected to an intermediate shaft (not shown) via a universal joint (not shown), so that the rotation (steering torque) accompanying the steering operation is changed to the steering gear (rack & rack & It is configured to be transmitted to a steering mechanism that changes the steering angle of a steered wheel (not shown) such as a pinion mechanism.

  The column shaft 4 of the present embodiment is allowed to slide in the axial direction with respect to the upper shaft 11 by being spline-fitted to the hollow upper shaft 11 to which the steering 2 is fixed and the upper shaft 11. The lower shaft 12 is provided. The steering column 6 includes an outer tube 13 that accommodates and supports the upper shaft 11 via the bearing 5a, and an inner tube 14 that accommodates and supports the lower shaft 12 via the bearing 5b. The inner tube 14 is inserted into the inner periphery of the inner tube 14 so as to be slidable in the axial direction with respect to the inner tube 14. Then, by moving the outer tube 13 and the upper shaft 11 relative to the inner tube 14 and the lower shaft 12, a telescopic function that enables adjustment of the steering position in the axial direction is realized.

  The steering column 6 of the present embodiment is supported by a link mechanism (not shown) so as to be tiltable in the vertical direction, and by tilting the column shaft 4 together with the steering column 6, the steering position in the vertical direction can be adjusted. The tilt function is realized.

  As shown in FIG. 2, the rudder angle ratio variable mechanism 7 includes a substantially rectangular parallelepiped cam member 21 connected to the other end of the column shaft 4 (lower shaft 12) so as to be integrally rotatable. The cam member 21 is formed with a substantially linear cam groove 22 that extends in a direction orthogonal to the axial direction of the column shaft 4 and the output shaft 8 and opens toward the output shaft 8. Further, the rudder angle ratio variable mechanism 7 includes a cam follower 23 slidably provided in a cam groove 22 formed in the cam member 21 and the predetermined amount (an eccentric amount between the column shaft 4 and the output shaft 8). In addition, an eccentric pin 24 that connects the output shaft 8 and the cam follower 23 is provided at a position that is greatly eccentric. That is, in this embodiment, the column shaft 4 corresponds to the first axis, and the output shaft 8 corresponds to the second axis.

  Specifically, a fitting hole 31 is formed at the other end of the lower shaft 12, and a protruding portion 32 that protrudes toward the lower shaft 12 in the axial direction is formed on the cam member 21. The cam member 21 is coupled to the lower shaft 12 (column shaft 4) so as to be integrally rotatable. A substantially annular connecting member 34 is fixed coaxially with the output shaft 8 on one end side of the output shaft 8. The connecting member 34 is formed with a mounting hole 35 at which the other end of the eccentric pin 24 is fixed at the center thereof, that is, at a position farther from the axis L2 of the output shaft 8 than the predetermined amount. The eccentric pin 24 is provided such that its axis L3 is parallel to the axis L3 of the column shaft 4 and the axis L2 of the output shaft 8. The cam follower 23 is formed with an insertion hole 36 penetrating in the direction of the axis L3. One end of the eccentric pin 24 is inserted into the insertion hole 36 via a needle bearing 37, thereby being connected to the cam follower 23. Has been. Thereby, the cam follower 23 is configured to be rotatable about the eccentric pin 24. In the present embodiment, the tip of the output shaft 8 is inserted into the cam groove 22, and the shape of the portion of the cam groove 22 where the output shaft 8 is inserted does not hinder the rotation of the cam member 21. It is formed in an arc shape (see FIG. 3).

  Therefore, the rotation of the cam member 21 connected to the column shaft 4 is allowed by the sliding of the cam follower 23 in the cam groove 22 and the rotation of the cam follower 23 around the eccentric pin 24. As shown in FIG. 3, the steering angle ratio variable mechanism 7 moves the eccentric pin 24 connected to the cam follower 23 on the concentric circle of the output shaft 8 with the rotation of the cam member 21. The rotation is transmitted to the output shaft 8.

  Here, in the figure, the circle indicated by the broken line indicates the locus of the eccentric pin 24 (the axis thereof) that moves as the cam member 21 rotates. Each circle indicated by a two-dot chain line indicates the same eccentric pin corresponding to the rotation (60 ° interval) of the cam member 21 from the position (P0) of the eccentric pin 24 in the steering neutral position (steering angle zero) indicated by the solid line. 24 positions (P1, P2, P1 ′, P2 ′, P3) are shown. As shown in the figure, the closer the position of the eccentric pin 24 is to “P0”, the smaller the position change of the eccentric pin 24 with respect to the rotation angle change of the cam member 21, and the position of the eccentric pin 24 is “ The closer to “P3”, the larger the position change of the eccentric pin 24 with respect to the rotation angle change of the cam member 21.

  In this way, the steering angle ratio variable mechanism 7 connects the column shaft 4 and the output shaft 8 arranged eccentrically to each other so as to be able to transmit rotation, and changes in the rotation angle of the column shaft 4 caused by the steering operation and the rotation angle of the output shaft 8. The relationship between the change, that is, the relationship between the change in the steering angle and the change in the steering angle (steering angle) of the steered wheels can be made non-linear.

  The steering device 1 is configured as a so-called column-type electric power steering device. More specifically, as shown in FIGS. 1 and 2, the output shaft 8 is supported by bearings 41 a to 41 c so that the output shaft 8 is fixed within the sensor housing 42 and the worm housing 43 fixed to the other end of the steering column 6. It is housed rotatably. A worm wheel 44 is fixed to the outer periphery of the output shaft 8. An assisting force can be applied to the steering system by decelerating the rotation of a motor (not shown) and transmitting it to the output shaft 8 by a speed change mechanism comprising a worm wheel and a worm gear (not shown). It has become a structure.

  Here, the steering device 1 has a built-in torque sensor 46 for detecting a steering torque transmitted through the column shaft 4. Specifically, the output shaft 8 is configured by connecting an upper shaft 47 coupled to the coupling member 34 and a lower shaft 48 provided with the worm wheel 44 via a torsion bar 49. Yes. The torque sensor 46 is configured to detect the steering torque input to the steering system by measuring the torsion angle of the torsion bar 49. A control device (not shown) is configured to control the assist force applied to the steering system based on the steering torque detected by the torque sensor 46.

(Backlash structure of rudder angle ratio variable mechanism)
Next, a description will be given of a backlash-packing configuration of the rudder angle ratio variable mechanism in the present embodiment.
As described above, when a backlash (gap) is formed between the cam follower 23 and the cam groove 22, there is a problem that abnormal noise may occur due to the backlash.

  In consideration of this point, as shown in FIG. 4, the cam follower 23 is pressed against the rudder angle ratio variable mechanism 7 toward the bottom 22 a side of the cam groove 22 in the axial direction of the eccentric pin 24 (hereinafter referred to as the axial bottom side). A spring member 51 as a pressing means is provided. In the present embodiment, the spring member 51 is configured by a wave washer, a disc spring, or the like. And each sliding surface 53 with the outer peripheral surface 52 of the cam follower 23 and the outer peripheral surface 52 of the cam groove 22 presses the cam follower 23 by the spring member 51, so that the outer peripheral surface 52 and each sliding surface 53 are mutually connected. The cam grooves 22 are formed so as to be in contact with each other so as to be inclined from the opening 22b side to the bottom 22a side in the axial direction.

  More specifically, the outer peripheral surface 52 is formed to taper from the opening 22b side of the cam groove 22 toward the bottom 22a side, and each sliding surface 53 is formed from the opening 22b side of the cam groove 22. It forms so that it may mutually adjoin, as it goes to the bottom part 22a side. Specifically, as shown in FIG. 4, the outer peripheral surface 52 is formed in a linear shape that tapers from the opening 22 b side to the bottom 22 a side of the cam groove 22 in the longitudinal direction of the cam groove 22. ing. On the other hand, each sliding surface 53 is formed in a straight line shape parallel to a portion of the outer peripheral surface 52 with which each sliding surface 53 abuts in the longitudinal direction. In the present embodiment, the outer peripheral surface 52 and the sliding surfaces 53 are formed such that the angle of the eccentric pin 24 with respect to the axis L3 is an inclination angle θ (for example, 2 to 3 °).

  The eccentric pin 24 is formed with an annular flange portion 55 extending along the radial direction. And the spring member 51 is arrange | positioned between the cam follower 23 and the flange part 55, and this cam follower 23 is pressed toward the axial direction bottom part side (upper side in FIG. 4). Further, a nut 56 as a restricting member is fixed to the bottom side of the eccentric pin 24 in the axial direction, and the nut 56 restricts the cam follower 23 from moving to the bottom side of the eccentric pin 24 in the axial direction. It has become.

  In the steering angle ratio variable mechanism 7 configured as described above, the cam member 21 is rotated together with the column shaft 4 by the steering operation, and the transmission force F along the radial direction from the cam member 21 (cam groove 22) to the cam follower 23 is generated. As shown in FIG. 5, the cam follower 23 moves toward the opening 22b of the cam groove 22 in the axial direction, and the spring member 51 is elastically deformed. At this time, since the sliding surface 53 and the outer peripheral surface 52 of the cam groove 22 are inclined at a predetermined angle θ with respect to the axis L3 as described above, the component force f1 (= Only Ftanθ) acts.

  Therefore, in the steering angle ratio variable mechanism 7 of the present embodiment, the rotation (steering torque) accompanying the steering operation is applied to the output shaft 8 by the spring member 51 receiving the component force f1 of the transmission force F corresponding to the inclination angle θ. Communicated. Since the spring member 51 returns to its original shape as the transmission force F (component force f1) decreases, the transmission force F does not act between the cam groove 22 and the cam follower 23. The play between the outer peripheral surface 52 and each sliding surface 53 of the cam groove 22 is in a packed state.

As described above, according to the present embodiment, the following operational effects can be achieved.
(1) The steering device 1 includes a steering angle ratio variable mechanism 7 that connects the column shaft 4 and the output shaft 8 that are arranged eccentrically with each other by a predetermined amount so as to be able to transmit rotation. The steering angle ratio variable mechanism 7 is connected to the column shaft 4 and includes a cam member 21 having a cam groove 22, a cam follower 23 slidably provided in the cam groove 22, an output shaft 8, and a cam follower 23. And an eccentric pin 24 to be connected. The cam follower 23 is provided with a spring member 51 that presses the cam follower 23 toward the bottom in the axial direction, and the cam follower 23 is pressed against the outer peripheral surface 52 of the cam follower 23 and each sliding surface 53 of the cam groove 22 by the spring member 51. Each of the surfaces 52 and 53 is formed so as to be inclined from the opening 22b side to the bottom 22a side of the cam groove 22 so as to contact each other.

  According to the above configuration, since the cam follower 23 is pressed by the spring member 51 and the outer peripheral surface 52 and the sliding surfaces 53 come into contact with each other, the backlash between them is reduced. When rotating, the outer peripheral surface 52 and the sliding surface 53 do not collide, and it is possible to prevent the generation of abnormal noise. Further, since the outer peripheral surface 52 and the sliding surfaces 53 are in contact with each other, the change in the rotation angle of the column shaft 4 is quickly transmitted to the output shaft 8 and the responsiveness can be improved.

  The force acting on the spring member 51 when the column shaft 4 rotates is the inclination angle θ of the outer peripheral surface 52 and the sliding surface 53 among the transmission force F transmitted between the cam member 21 and the cam follower 23. Therefore, the load acting on the spring member 51 with the steering operation can be kept low. Thereby, it can suppress that a big load is added to the spring member 51 and it deteriorates. Furthermore, since the cam follower 23 and the eccentric pin 24 are inserted into the cam groove 22 along the axial direction, the rudder angle ratio variable mechanism 7 can be assembled in a state of looseness, so that the assembling property is good. Furthermore, since the spring member 51 presses the cam follower 23 in the axial direction, the same spring member 51 can be used regardless of the size (outer diameter, etc.) of the cam follower 23, and the sizes are different. Parts can be shared between the rudder angle ratio variable mechanisms that employ cam followers, and costs can be reduced.

  (2) The outer peripheral surface 52 is formed in a straight line shape that tapers from the opening 22b side to the bottom 22a side of the cam groove 22 in the longitudinal direction of the cam groove 22, and each sliding surface 53 is viewed in the longitudinal direction. Each of the outer peripheral surfaces 52 was formed in a straight line parallel to a portion where the sliding surfaces 53 contact each other. According to the above configuration, since the outer peripheral surface 52 of the cam follower 23 and the sliding surfaces 53 of the cam groove 22 are in surface contact with each other, it is possible to suppress excessive pressure from acting between them, for example, the cam follower 23 and the cam The life of the groove 22 (cam member 21) can be extended.

  (3) A flange portion 55 extending radially outward is formed on the eccentric pin 24, and a spring member 51 is provided between the flange portion 55 and the cam follower 23 so as to press the cam follower 23 toward the bottom in the axial direction. did. According to the above configuration, for example, the shape of the eccentric pin 24 can be simplified as compared with the case where the eccentric pin 24 is integrally formed with a portion that presses the cam follower 23.

  (4) By forming the insertion hole 36 in the cam follower 23 and inserting the eccentric pin 24 into the insertion hole 36, the cam follower 23 is rotatably connected around the eccentric pin 24, and the cam follower is connected to the eccentric pin 24. A nut 56 is provided for restricting the movement of the eccentric pin 24 toward the bottom in the axial direction with respect to the eccentric pin 24. According to the above configuration, the cam follower 23 can be prevented from falling off the eccentric pin 24 by the nut 56, and the assembling property can be improved. Further, the spring member 51 can be elastically deformed in advance by the nut 56 before the steering angle ratio variable mechanism 7 is assembled, and the load by which the cam follower 23 is pressed in the axial direction by the spring member 51 can be easily set. Can do.

In addition, the said embodiment can also be implemented in the following aspects which changed this suitably.
In the above embodiment, the flange portion 55 extending in the radial direction is formed on the eccentric pin 24, and the pressing member is configured by the spring member 51 disposed between the flange portion 55 and the cam follower 23. Not limited to this. For example, as shown in FIG. 6, the eccentric pin 24 is formed to extend from the eccentric pin 24, and is inclined toward the bottom 22a side of the cam groove 22 in the axial direction toward the outer side in the radial direction and elastically deformable in the axial direction. The elastic flange portion 61 may be integrally formed, and the cam follower 23 may be pressed by the elastic flange portion 61. In addition, in the same figure, the state which the elastic flange part 61 elastically deformed is shown with a dashed-two dotted line. According to this structure, compared with the case where the spring member 51 for pressing the cam follower 23 is provided separately, the number of parts can be reduced.

In the above-described embodiment, the elastic body is configured by the spring member 51 such as a wave washer. However, the elastic body may be configured by rubber or a resin material without being limited thereto.
In the above embodiment, the cam member 21 is formed in a substantially rectangular parallelepiped shape. However, the present invention is not limited to this, and if the cam groove 22 that extends in the direction orthogonal to the axial direction and opens toward the output shaft 8 is formed, the cam member 21 The member 21 may be formed in other shapes such as a disk shape.

  In the above embodiment, the outer peripheral surface 52 is formed in a linear shape that tapers from the opening 22b side to the bottom 22a side of the cam groove 22 when viewed from the longitudinal direction of the cam groove 22, but the present invention is not limited to this. As shown in FIG. 7, the outer peripheral surface 52 may be formed in a curved shape protruding outward in the radial direction. Similarly, each sliding surface 53 of the cam groove 22 may have a curved shape protruding radially inward, and the outer peripheral surface 52 and each sliding surface 53 come into contact with each other when the cam follower 23 is pressed to the bottom side. Any other shape may be used.

In the above embodiment, the nut 56 is provided on the distal end side of the eccentric pin 24. However, the configuration is not limited thereto, and a configuration in which a regulating member such as the nut 56 is not provided may be employed.
In the above embodiment, the column shaft 4 is configured as the first axis, and the output shaft 8 is configured as the second axis. However, the present invention is not limited to this, and the output shaft 8 is configured as the first shaft and the cam member 21 is provided on the output shaft 8, and the column shaft 4 is configured as the second shaft and the eccentric pin 24 is provided on the column shaft 4. You may make it provide.

  In the above embodiment, the present invention is embodied in the steering device 1 configured as a column assist type electric power steering device (EPS). However, the present invention is not limited to this, and the present invention may be applied to an EPS other than column assist, a hydraulic power steering device, or a non-assist type steering device such as a so-called rack assist type.

  DESCRIPTION OF SYMBOLS 1 ... Steering device, 2 ... Steering, 3 ... Steering shaft, 4 ... Column shaft, 7 ... Steering angle ratio variable mechanism, 8 ... Output shaft, 21 ... Cam member, 22 ... Cam groove, 22a ... Bottom part, 22b ... Opening part , 23 ... Cam follower, 24 ... Eccentric pin, 36 ... Insertion hole, 51 ... Spring member, 52 ... Outer peripheral surface, 53 ... Sliding surface, 55 ... Flange part, 56 ... Nut, 61 ... Elastic flange part, θ ... Inclination angle .

Claims (5)

A first shaft and a second shaft arranged eccentrically with each other by a predetermined amount, and a rudder angle ratio variable mechanism that connects the first shaft and the second shaft so as to be able to transmit rotation,
The variable steering angle ratio mechanism is connected to the first shaft and has a cam member having a cam groove, a cam follower slidably provided in the cam groove, and the second shaft and the cam follower. With an eccentric pin that
The cam groove extends in a direction orthogonal to the axial direction of each axis and opens to the second axis side,
In the steering device, wherein the eccentric pin connects the second shaft and the cam follower at a position eccentric from the second shaft by a larger amount than the predetermined amount.
A pressing means for pressing the cam follower, and the pressing means presses the cam follower toward the bottom side of the cam groove in the axial direction;
The sliding surfaces of the outer peripheral surface of the cam follower and the outer peripheral surface of the cam groove are such that the outer peripheral surface and the sliding surfaces come into contact with each other when the cam follower is pressed by the pressing means. The steering device is characterized in that each of the cam grooves is inclined from the opening side to the bottom side in the axial direction. The steering apparatus according to claim 1, wherein
The outer peripheral surface is formed in a linear shape that tapers from the opening side of the cam groove toward the bottom side in the longitudinal direction of the cam groove,
Each of the sliding surfaces is formed in a straight line parallel to a portion of the outer peripheral surface with which each sliding surface abuts when viewed in the longitudinal direction. The steering apparatus according to claim 1 or 2,
The eccentric pin is formed with a flange portion extending radially outward,
The steering device according to claim 1, wherein the pressing means is an elastic body provided between the flange portion and the cam follower. The steering apparatus according to claim 1 or 2,
The pressing means is an elastic flange portion extending radially outward from the eccentric pin, and the elastic flange portion is inclined toward the bottom side of the cam groove in the axial direction as it goes radially outward. A steering apparatus characterized by being elastically deformable in the axial direction. The steering apparatus according to claim 3 or 4,
An insertion hole is formed in the cam follower, and the cam follower is rotatably connected around the eccentric pin by inserting the eccentric pin into the insertion hole.
A restriction member is provided on the bottom side of the eccentric pin in the axial direction, and the restriction member restricts the cam follower from moving to the bottom side of the cam groove in the axial direction with respect to the eccentric pin. A steering device characterized by the above.

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