JP2010126112A - Vehicle steering force transmitting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To transmit steering force even in the state that a protruded portion of a rotation transmitting mechanism is broken. <P>SOLUTION: This steering force transmitting device includes a first shaft 88, etc., a second shaft 60 arranged deviating a predetermined distance from the shaft, and the rotation transmitting mechanism having (a) a protruded portion 122, etc., of the first shaft protruded on a position a distance apart from the rotational axis of the fist shaft in the direction of the rotational axis and (b) a groove 114 formed in the end of the second shaft, for transmitting the rotation of the second shaft to the first shaft with the protruded portion engaging with the groove. A movable part 130 of the first shaft, movable forward/backward relative to the end of the second shaft, normally does not engage with the groove in the state of being moved backward, and it is moved into the groove with elastic force to function as a second engaging part, as two shafts are relatively rotated when the protruded portion is broken. With this structure, it is possible to transmit steering force even in the state that the protruded portion is broken. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a vehicle steering force transmission device that transmits a steering force input to a steering operation member to a steering device.

In recent years, a rotational phase of a shaft (hereinafter sometimes referred to as a “first shaft”) whose one end is coupled to one of a steering operation member operated by a driver and a steering device that steers a wheel; One rotation of the first shaft and the second shaft while changing the rotational phase difference which is the difference from the rotational phase of a shaft (hereinafter also referred to as “second shaft”) to which one end is connected to the other. Development of a vehicle steering force transmission device including a rotation transmission mechanism that transmits the torque to the other side is underway. The following patent document describes an example of a steering force transmission device including the rotation transmission mechanism.
JP-A-3-227772

  The rotation transmission mechanism includes a protrusion provided at the other end of the first shaft and a groove having a pair of side wall surfaces formed at the other end of the second shaft. The two shafts are connected by engaging the groove with the protruding portion sandwiched between the pair of side wall surfaces, and one of the two shafts rotates through the protruding portion and the side wall surface. Is transmitted to the other. In the vehicle steering force transmission device having the rotation transmission mechanism having such a structure, when the protruding portion is damaged, the two shafts are disconnected and the two shafts freely rotate relative to each other. The steering force input to the steering operation member may not be transmitted to the steering device. The present invention has been made in view of such a situation, and even if the connection of the two shafts by the protruding portion is broken, the steering force input to the steering operation member is applied to the steering device. It is an object to provide a vehicle steering force transmission device capable of transmission.

  In order to solve the above-described problem, the vehicle steering force transmission device according to the present invention is configured such that the first shaft, the rotation axis of the first shaft and the rotation axis of the first shaft are parallel to each other, and the rotation axes are shifted by a predetermined distance. A second shaft arranged in a state; and (A) the first shaft from the main body of the first shaft at a position away from the predetermined distance in the radial direction of the first shaft from the rotation axis of the first shaft. The protruding portion of the first shaft provided in the flange portion in a state protruding from the flange portion of the first shaft protruding in the radial direction of the first shaft in the rotation axis direction that is the direction in which the rotation axis of the first shaft and the second shaft extends. And (B) provided at the other end portion of the second shaft so as to extend in the radial direction of the second shaft, and has a pair of side wall surfaces between which the protruding portion of the first shaft fits and which sandwiches the protruding portion. And protrusion A rotation transmission mechanism configured to include a radial groove that allows movement of the second shaft in the radial direction, and transmits one rotation of the first shaft and the second shaft to the other while changing a rotation phase difference. And a movable portion provided with a first shaft in a state in which the first shaft is allowed to advance and retreat with respect to the other end portion of the second shaft. An elastic body that elastically deforms as the part retreats, and the movable part is pressed against the other end of the second shaft by the elastic force in the retracted state, and the protruding part is damaged. Along with the relative rotation of the two shafts, it is configured to advance into the radial groove by an elastic force and function as a second engagement portion.

  The vehicle steering force transmission device according to the present invention is provided on the first shaft when the projecting portion is damaged and the two shafts are disconnected by the projecting portion and the two shafts rotate relative to each other. The movable portion is engaged with the radial groove and functions as a second engaging portion. Therefore, according to the vehicle steering force transmission device of the present invention, the steering force input to the steering operation member is transmitted to the steering device even when the connection between the two shafts by the protrusion is broken. It becomes possible.

Aspects of the Invention

  In the following, some aspects of the invention that can be claimed in the present application (hereinafter sometimes referred to as “claimable invention”) will be exemplified and described. As with the claims, each aspect is divided into sections, each section is numbered, and is described in a form that cites the numbers of other sections as necessary. This is merely for the purpose of facilitating the understanding of the claimable inventions, and is not intended to limit the combinations of the constituent elements constituting those inventions to those described in the following sections. In other words, the claimable invention should be construed in consideration of the description accompanying each section, the description of the embodiments, etc., and as long as the interpretation is followed, another aspect is added to the form of each section. In addition, an aspect in which constituent elements are deleted from the aspect of each item can be an aspect of the claimable invention. In each of the following items, item (1) corresponds to claim 1, item (2) corresponds to claim 2, and item (3) corresponds to claim 3.

(1) a first shaft having one end connected to one of a steering operation member operated by a driver and a steering device that steers a wheel, and rotatably disposed;
One end is connected to the other of the steering operation member and the steering device, and the rotation axis of the first shaft and the rotation axis of the first shaft are parallel to each other, and the rotation axis is rotatable by a predetermined distance. A second shaft disposed on
(A) at the other end of the first shaft, an engaging portion provided at a position away from the predetermined distance in the radial direction of the first shaft from the rotation axis of the first shaft; The other end of the two shafts is provided so as to extend in the radial direction of the second shaft, and engages with the engaging portion of the first shaft, and the engaging portion in the radial direction of the second shaft. And a guide passage that allows movement, and by rotating one of the first shaft and the second shaft, a rotation phase difference that is a difference between rotation phases of the first shaft and the second shaft is obtained. A vehicle steering force transmission device comprising a rotation transmission mechanism configured to rotate while the other is rotating,
The first shaft is integrated with the first shaft main body at (i) a first shaft main body which is a main body of the first shaft, and (ii) an end of the first shaft main body on the second shaft side. A first shaft flange portion that protrudes from the first shaft main body portion in the radial direction of the first shaft; and (iii) the predetermined axis direction from the rotation axis of the first shaft in the radial direction of the first shaft. At a position away from the distance, the rotation transmission projects from the first shaft flange toward the second shaft in the rotation axis direction that is the direction in which the rotation axes of the first shaft and the second shaft extend. And a protrusion functioning as an engaging portion of the mechanism,
The second shaft is integrated with the second shaft main body at (i) the second shaft main body which is the main body thereof, and (ii) the end of the second shaft main body on the first shaft side. And a second shaft flange that protrudes in the radial direction of the second shaft from the second shaft main body, and (iii) the first shaft of the second shaft flange at the second shaft flange. The rotation transmission is provided on the end surface on the shaft side so as to extend in the radial direction of the second shaft, and has a pair of side wall surfaces into which the protruding portion of the first shaft fits and sandwiches the protruding portion. A radial groove that functions as a guide passage for the mechanism,
The first shaft has a movable portion provided in a state in which the first shaft flange portion is allowed to advance and retract with respect to the end surface of the second shaft flange portion, and the end surface of the movable portion. And an elastic body that is elastically deformed with the retreat of
The movable part is
In a state of being retracted with respect to the end surface, the elastic body is pressed against a portion of the end surface of the second shaft flange portion where the radial groove is not open,
When the projecting portion is damaged, the first shaft and the second shaft are rotated relative to each other to advance into the radial groove by the elastic force of the elastic body and function as a second engaging portion. A steering force transmission device for a vehicle.

  A protrusion provided on the other end of the first shaft and a radial groove having a pair of side walls provided on the other end of the second shaft, the protrusion being a pair of side walls; In the rotation transmission mechanism having a structure in which the two shafts are coupled by being engaged with the radial groove while being sandwiched between the two shafts, the rotation of one of the two shafts is transmitted to the other through the protrusion. Yes. In the vehicle steering force transmission device including the rotation transmission mechanism having such a structure, the two shafts are free when the projection is damaged and the connection between the two shafts by the projection is released. The steering force input to the steering operation member may not be transmitted to the steering device.

  In the vehicle steering force transmission device described in this section, the movable portion is provided on the first shaft collar in a state where the advancing and retreating operation is possible with respect to the end surface of the second shaft collar where the radial groove opens. The movable part is normally not engaged with the radial groove in the retracted state. However, when the protrusion is damaged and the two shafts rotate freely relative to each other, the movable part and the radial groove face each other, and the movable part advances into the radial groove and engages with the radial groove. Match. That is, the steering force transmission device described in this section includes a second engagement portion that engages with the radial groove when the connection between the two shafts is released due to the breakage of the protrusion. Therefore, according to the steering force transmission device described in this section, it is possible to transmit the steering force input to the steering operation member to the steering device even when the protruding portion is damaged, and fail-safe It is possible to realize a device that is excellent in terms of viewpoint.

  The “rotation transmission mechanism” described in this section changes the difference between the rotation angle of the first shaft and the rotation angle of the second shaft. Here, the shaft connected to the steering operation member of the two shafts in a state where there is no rotation angle difference (rotation phase difference) between the two shafts (hereinafter sometimes referred to as “operation member side shaft”). The rotation angle is defined as a reference rotation angle, and the rotation transmission mechanism will be specifically described. For example, when the operating member side shaft rotates from the reference rotation angle, a shaft (hereinafter referred to as the “steering device side”) connected to the steering device of the two shafts until the operating member side shaft rotates 180 °. The rotation angle of the “shaft” may be smaller than the rotation angle of the operation member side shaft. Alternatively, the rotation angle of the steering device side shaft is larger than the rotation angle of the operation member side shaft. When the operating member side shaft rotates 180 °, the steered device side shaft also rotates 180 °, and the difference between the rotation angles of the two shafts disappears.

  That is, when the operating member side shaft rotates from the reference rotation angle to 180 °, the rotation angle difference increases from 0 and decreases from the middle to reach 0. If the ratio of the rotation speed of the steering device side shaft to the rotation speed of the operation member side shaft is defined as the steering gear ratio, in this case, the gear ratio increases as the operation member side shaft rotates from the reference rotation angle to 180 °. Larger or smaller. For example, the gear ratio is configured to increase as the operation member side shaft rotates, and the reference rotation angle corresponds to the position where the steering operation member corresponds to the steering neutral position of the wheel, that is, the neutral operation position. If the steering angle of the steering member is small, the steering angle of the steering member is increased and the steering angle of the steering member is increased when the steering angle of the steering member is small. As a result, it is possible to realize handling with good response. Therefore, in a vehicle equipped with the “steering force transmission device” described in this section, a steering system that relies on an actuator such as an electromagnetic motor to change the steering amount of the wheel with respect to the operation amount of the steering operation member, so-called steering. The operation feeling of the steering operation member can be changed as described above without mounting a steering ratio variable steering system (VGRS (Variable Gear Ratio Steering) system) or the like.

  “When the protruding portion is damaged” described in this section means that when the connection between the first shaft and the second shaft by the protruding portion is released due to the damage of the protruding portion, in other words, the first portion due to the damage of the protruding portion. It means the case where the shaft and the second shaft are freely rotated relative to each other. For example, the case where the protrusion and the first shaft collar are divided, the case where the protrusion is detached from the first shaft, etc. Yes.

  Each of the “first shaft flange” and the “second shaft flange” described in this section may protrude from a part of the outer peripheral surface of the main body of each shaft in the radial direction of each shaft. Well, what protrudes in the radial direction of each shaft over the entire circumference of the outer peripheral surface of the main body portion of each shaft, specifically, for example, may be a circular flange portion. The “radial groove” described in this section only needs to have a pair of side wall surfaces sandwiching the protrusion, and the “radial groove” may or may not have a bottom. That is, the “radial groove” may have a structure penetrating from one end surface of the second shaft flange portion to the other end surface. Further, the connection between the one end portion of the steering device side shaft and the steering device, or the connection between the one end portion of the operation member side shaft and the operation member may be such that they are directly connected, It may be connected between them via an damage shaft, a universal joint or the like.

(2) The protrusion has a cylindrical outer peripheral surface that contacts the pair of side wall surfaces,
The movable portion has a cylindrical outer peripheral surface that contacts the pair of side wall surfaces in a state where the movable portion has advanced into the radial groove,
The vehicle steering force transmission device according to (1), wherein an outer diameter of the outer peripheral surface of the movable portion is smaller than an outer diameter of the outer peripheral surface of the protruding portion.

  The movable part that engages the radial groove in a state where the protrusion is damaged should be used as an auxiliary, and it is desirable that such damage be repaired as soon as possible. For this reason, it is desirable for the driver to quickly detect that the protruding portion is damaged. In the steering force transmission device described in this section, the outer diameter of the movable portion that engages with the radial groove when the protrusion is damaged is larger than the outer diameter of the protrusion that normally engages with the radial groove. small. That is, the clearance (gap) between the movable portion and the pair of side wall surfaces in a state where the protrusion is damaged is larger than the clearance between the normal protrusion and the pair of side wall surfaces. For this reason, in a state where the protruding portion is damaged, the driver feels a great sense of incongruity in the rotation operation of the steering operation member due to the large clearance. Therefore, according to the steering force transmission device described in this section, the driver can quickly detect the breakage of the protruding portion.

  (3) The vehicle steering force transmission device according to (1) or (2), wherein the movable portion has a shape with a tapered tip.

  In the steering force transmission device described in this section, since the tip of the movable portion is tapered, the movable portion is easily advanced into the radial groove. In particular, when the damaged protrusion remains in the radial groove while being sandwiched between the pair of side wall surfaces, and prevents the movable part from entering the radial groove, the tapered tip portion The movable portion is easily advanced into the radial groove by pushing the protruding portion.

(4) The protrusion is
A shaft body provided so as to extend in the rotational axis direction in a state of projecting from the first shaft flange portion toward the second shaft side;
Items (1) to (3) having a roller provided coaxially with the shaft body at a protruding portion of the shaft body and rotatable about the axis of the shaft body with respect to the first shaft flange portion. The steering force transmission device for a vehicle according to any one of items 1).

  In the steering force transmission device described in this section, the structure of the protrusion is specifically limited. By employing a roller for the projecting portion, the roller can be rolled in the radial groove, and smooth rotation transmission can be realized. However, when a roller is employed, a shaft body that holds the roller rotatably with respect to the first shaft collar is required, and the rotational force transmitted through the protrusion during transmission of the rotation is relatively large. It is considered that the load on the shaft body is considerably large. For this reason, at the time of rotation transmission, there exists a possibility that the shaft holding the roller may break and the protruding portion and the first shaft flange portion may be separated. Therefore, in the steering force transmission device described in this section, the effect of providing the movable portion functioning as the second engaging portion on the first shaft collar instead of the protruding portion is fully utilized.

  Hereinafter, embodiments of the claimable invention will be described in detail with reference to the drawings. In addition to the following examples, the claimable invention includes various aspects in which various modifications and improvements have been made based on the knowledge of those skilled in the art, including the aspects described in the above [Aspect of the Invention] section. Can be implemented.

<Overall configuration of vehicle steering system>
FIG. 1 shows the overall configuration of a vehicle steering system that is an embodiment of the claimable invention. The steering system includes a steering wheel 10 as a steering operation member operated by a driver, a steering force transmission device 12 that holds the steering wheel 10 at one end, a steering device 14 that steers a wheel, and a steering force. An intermediate shaft (hereinafter, may be abbreviated as “I / M shaft”) 16 positioned between the transmission device 12 and the steering device 14 is configured. Further, one end of the I / M shaft 16 and the output shaft 18 included in the steering force transmission device 12 are connected by a universal joint 20, and the other end of the I / M shaft 16 and the input shaft 22 included in the steering device 14. Is connected to one end of the other joint by another universal joint 24.

  In FIG. 1, the system is arranged so that the right side, that is, the steering wheel 10 side faces the rear of the vehicle, and the left side, that is, the steering device 14 side faces the front of the vehicle. A portion of the I / M shaft 16 passing through the hole is covered with a boot 28 so as to pass through a hole provided in the dash panel 26 that partitions the engine chamber.

  The steered device 14 includes an input shaft 22, a housing 30 as an outer shell member, and a steered rod 32 for steering a wheel, and the steered rod 32 moves in the axial direction thereof. It is possible to be held by the housing 30 and to extend in the vehicle width direction. Both ends of the steered rod 32 are connected to a steering knuckle (not shown) that holds each of the left and right front wheels. The input shaft 22 is rotatably held by the housing 30 and is engaged with the steered rod 32 in the housing 30. A pinion (not shown) is formed at the end portion of the input shaft 22 on the vehicle front side, and a rack (not shown) formed at an intermediate portion in the axial direction of the steered rod 32 meshes with the pinion. The steered rod 32 and the input shaft 22 are engaged.

  The steering force transmission device 12 is configured as a so-called steering column, and is fixedly supported on a part of the vehicle body by a steering support 36 provided in the instrument panel reinforcement 34. In the supported state, the steering force transmission device 12 is disposed in an inclined posture so that the front side of the vehicle is positioned downward as shown in the drawing. The steering force transmission device 12 is provided with a front bracket 38 at the front portion thereof, and a breakaway bracket (hereinafter sometimes abbreviated as “B.A.BKT”) 40 on the vehicle rear side of the front bracket 38. The front bracket 24 and the B.A.BKT 40 are each attached to the steering support 22 so that the steering force transmission device 12 is supported at two locations. The supported steering force transmission device 12 is in a state in which a rear portion projects from the instrument panel 42 toward the vehicle rear side, and a steering wheel 10 is attached to the projecting rear end portion. A portion of the steering force transmission device 12 that protrudes from the instrument panel 42 is covered with a column cover 44, and a lower part is covered with an instrument panel lower cover 46.

  FIG. 2 shows a side sectional view of the steering force transmission device 12. The steering force transmission device 12 can be roughly divided into a column section 50 that holds the steering wheel 10 and can be expanded and contracted in the axial direction, and an EPS section 52 that is a main body that realizes an electric power steering function. The two sections 50 and 52 are integrated. Hereinafter, each of these sections will be described in order.

  The column section 50 includes a main shaft 54 that holds the steering wheel 10 at an end on the vehicle rear side, and a column tube 56 that serves as a housing that rotatably holds the main shaft 54 in a state where the main shaft 54 is inserted. ing. The main shaft 54 includes an upper shaft 58 positioned on the vehicle rear side, that is, on the upper side, and a lower shaft 60 positioned on the vehicle front side, that is, on the lower side. The upper shaft 58 is formed in a pipe shape and the lower shaft 60 is formed in a rod shape, and the rear portion of the lower shaft 60 is inserted into the front portion of the upper shaft 58. The upper shaft 58 and the lower shaft 60 are spline-fitted, and the upper shaft 58 and the lower shaft 60 are connected in a state in which they can be relatively moved in the rotation axis direction but cannot be relatively rotated. That is, the main shaft 54 has a structure that can be expanded and contracted in the rotation axis direction. Incidentally, the lower shaft 60 is composed of a shaft main body portion 62 on the rear side of the lower shaft 60 and a circular flange portion 64 having an outer diameter larger than the outer diameter of the shaft main body portion 62 on the front side of the shaft main body portion 62. The circular flange portion 64 is connected to an EPS section 52 described later. In the steering force transmission device 12, the shaft main body portion 62 of the lower shaft 60 and the upper shaft 58 constitute a shaft main body portion of the main shaft 54, and the circular flange portion 64 constitutes a flange portion.

The column tube 56 includes an upper tube 66 positioned on the vehicle rear side (upper side) and a lower tube 68 positioned on the vehicle front side (lower side). The upper tube 66 and the lower tube 68 are both cylindrical, and the rear part of the lower tube 68 as the second cylinder member is fitted in the front part of the upper tube 66 as the first cylinder member. The lower tube 68 has a stepped shape, a small-diameter portion 70 having an outer diameter smaller than the inner diameter of the upper tube 66 in a rear portion thereof, and a large-diameter portion having an outer shape larger than the inner diameter of the upper tube 66 in a front portion thereof. 72, and a stepped portion 74 that connects the small diameter portion 70 and the large diameter portion 72. A liner (not shown) is provided between the small-diameter portion 70 of the lower tube 68 and the upper tube 66, and the lower tube 68 is fitted into the upper tube 66 without rattling through the liner. At the same time, the relative movement of the upper tube 66 and the lower tube 68 in the rotational axis direction is facilitated. That is, the column tube 56 has a structure that can be expanded and contracted in the rotation axis direction.

  A radial bearing 76 is disposed at the rear end portion of the upper tube 66, and a radial bearing 78 is disposed at the large-diameter portion 72 of the lower tube 68 via a housing of an EPS section 52 described later. . The main shaft 54 is rotatably held by the bearings 76 and 78. With such a structure, the column section 50 can be expanded and contracted while ensuring the rotation of the main shaft 54.

  FIG. 3 shows a side cross-sectional view of the EPS section 52. The EPS section 52 includes an output shaft 18 for outputting a steering force applied to the steering wheel 10 to the steering device, and an electromagnetic motor 80 as a drive source. The motor 80 rotates the output shaft 18. A steering assisting device 82 that assists the output and an EPS housing 84 that rotatably holds the output shaft 18 and accommodates the steering assisting device 82 are included. The output shaft 18 is configured by integrating an output side shaft 86, an input side shaft 88, and a torsion bar 90. The output side shaft 86 extends from the front side of the vehicle of the EPS housing 84 and is connected to the I / M shaft 16 via the universal joint 20 at the extended portion, and outputs rotation to the steering device 14. To do.

  The output side shaft 86 has a hollow structure, and the input side shaft 88 is inserted into a portion of the output side shaft 86 on the vehicle rear side. A bearing 92 is interposed between the inner peripheral surface of the output side shaft 86 and the outer peripheral surface of the input side shaft 88, and the output side shaft 86 and the input side shaft 88 can be rotated relative to each other. The input side shaft 88 has a bottomed hole that opens in an end surface on the vehicle front side and extends in the rotation axis direction. One end of the torsion bar 90 is fixed to the bottom of the bottomed hole by a pin 94, and the other end of the torsion bar 90 is a through hole that passes through the output shaft 86 in the rotation axis direction. It is fixed to the front end by a pin 96. With such a configuration, the output shaft 18 allows the torsion bar 90 to be twisted, and is itself twisted accordingly. Further, the output side shaft 86 is rotatably held by the EPS housing 84 via two radial bearings 98 and 100 on the outer periphery thereof, and the input side shaft 88 is attached to the EPS housing 84 via the needle bearing 102 on the outer periphery thereof. It is held rotatably.

  The steering assist device 82 includes the electromagnetic motor 80, a worm 104 connected to the motor shaft of the electromagnetic motor 80, and a worm wheel 106 that meshes with the worm 104. The worm wheel 106 is fixed to the output side shaft 86 of the output shaft 18 and cannot be rotated relative to the output side shaft 86. With such a structure, a rotational force is applied to the worm 104 by the electromagnetic motor 80, and a rotational force is applied to the worm wheel 106. That is, the steering assist device 82 generates a steering assist force (also referred to as a “steering assist force”) that assists the steering of the wheel by assisting the rotation output of the output shaft 18 by the electromagnetic motor 80. It is structured.

  The EPS section 52 includes a rotation angle sensor 108. The rotation angle sensor 108 is a difference between the rotation angle position of the output side shaft 86 to which the vehicle front portion of the torsion bar 90 is fixed and the rotation angle position of the input side shaft 88 to which the vehicle rear portion of the torsion bar 90 is fixed. It is a device for detecting a certain amount of relative rotational displacement. The steering torque can be estimated on the basis of the relative rotational displacement amounts of the two shafts 86 and 88, and the operation of the electromagnetic motor 80 is performed so as to generate a steering assist force according to the magnitude of the steering torque. Be controlled.

  The output shaft 18 is disposed in a state where the rotation axis of the main shaft 54 and the axis of the output shaft 18 are parallel to each other, and the rotation axes are shifted by a predetermined amount. It is connected to the part. Specifically, first, the lower shaft 60 constituting the main shaft 54 has a circular flange on the front end surface of the circular flange portion 64 as shown in FIG. 4 which is a cross-sectional view taken along the line AA ′ of FIG. A radial groove 114 extending in the radial direction of the portion 64 is formed. On the other hand, an annular ring plate 116 is fixedly fitted to the input side shaft 88 at the end on the rear side thereof. Incidentally, the annular plate 116 is indicated by a two-dot chain line in FIG.

  The rear end surface of the annular plate 116 and the front end surface of the circular flange portion 64 of the lower shaft 60 face each other with a small gap. A through hole extending in the rotation axis direction is formed in the annular plate 116, and a pin 118 as a shaft body is fixedly fitted into the through hole. The pin 118 protrudes from the annular plate 116 toward the vehicle rear side, and a roller 122 is provided on the protruding portion of the pin 118 via a needle bearing 120. The outer diameter of the roller 122 is slightly smaller than the width of the radial groove 114, that is, the distance between the pair of side wall surfaces 126 of the radial groove 114, and the roller 122 is engaged with the radial groove 114. Thus, the input side shaft 88, that is, the output shaft 18 is connected to the lower shaft 60 that constitutes the main shaft 54.

  In the present steering force transmission device 12, the pin 118, the needle bearing 120, and the roller 122 constitute a protruding portion that protrudes from the annular plate 116 in the direction of the rotation axis that is the direction in which the rotation axis of the input side shaft 88 extends. And the steering device side shaft as a 1st shaft is comprised by the protrusion part, the output shaft 18, and the annular plate 116 as a collar part. The shaft main body portion of the steering device side shaft is constituted by an input side shaft 88 and an output side shaft 86. Incidentally, the main shaft 54 as the operation member side shaft functions as a second shaft.

  Further, a generally cylindrical movable pin 130 is provided on the end surface of the annular plate 116 on the vehicle rear side, as shown in FIG. More specifically, the annular plate 116 is formed with a bottomed hole 132 that opens to the end surface of the circular plate 116 on the vehicle rear side, and the movable pin 130 is accommodated in the bottomed hole 132. . The outer diameter of the outer peripheral surface of the movable pin 130 is smaller than the inner diameter of the bottomed hole 132, and the movable pin 130 can be advanced and retracted relative to the circular flange portion 64. In addition, a coil spring 134 as an elastic body is disposed between the bottom of the bottomed hole 132 and the movable pin 130 in a compressed state, and the tip of the movable pin 130 is caused by the elastic force of the coil spring 134. Is pressed against the end face of the circular flange portion 64 on the vehicle rear side. It should be noted that another end of the annular plate 116 is symmetrically formed on the end surface of the annular plate 116 on the vehicle rear side, symmetrically with the bottomed hole 132 around the roller 122 as the projecting portion, as shown by a two-dot chain line in FIG. 136 is formed, and in the bottomed hole 136, similarly to the movable pin 130, another movable pin 138 is accommodated in a state where the coil spring is compressed.

  When the steering wheel 10 is rotated by the driver, the main shaft 54 rotates about its own rotation axis. At that time, the roller 122 engaged with the radial groove 114 formed in the circular flange portion 64 of the lower shaft 60 is displaced in the circumferential direction of the lower shaft 60 by the pair of side wall surfaces 126 of the radial groove 114. Is restricted, and the groove 114 allows the shaft 60 to move in the radial direction. That is, the pair of side wall surfaces 126 functions as a pair of guide surfaces, and the groove 114 functions as a guide passage. When the roller 122 is moved in the radial groove 114 with the rotation of the lower shaft 60, the rotational force of the lower shaft 60 is input to the input side via the roller 122, the pin 118, the annular plate 116, and the like. It is transmitted to the shaft 88, and the input side shaft 88 rotates around its own rotation axis. That is, the steering force transmission device 12 includes a rotation transmission mechanism that transmits the rotation around the rotation axis of the lower shaft 60 to the input side shaft 88 disposed so that the rotation axis of the lower shaft 60 is shifted from the rotation axis of the lower shaft 60. It is supposed to be. The rotation transmission mechanism includes an engaging portion as a protruding portion constituted by the roller 122, the pin 118, and the needle bearing 120, and a radial groove 114 as a guide passage. With the structure as described above, the steering force transmission device 12 transmits the steering force input to the steering wheel 10 to the steering device 18 via the I / M shaft 16 or the like.

  The steering force transmission device 12 is attached to a part of the vehicle body at the front end portion of the EPS section 52 and the upper tube 66 of the column section 50. The EPS bracket 84 of the EPS section 52 is fixedly provided with the front bracket 38 described above, and the front bracket 38 is provided with a shaft insertion hole 160. A bearing member 164 having a shaft hole 162 is fixed to the steering support 36, and the support shaft 166 is inserted into the shaft insertion hole 160 of the front bracket 38 and the shaft hole 162 of the bearing member 164. Thus, the steering force transmission device 12 is supported so as to be swingable about the support shaft 166.

  On the other hand, the column section 50 is held by the B.A.BKT 40, and the B.A.BKT 40 is attached to the steering support 36. More specifically, as shown in FIG. 6, the B.A.BKT 40 includes a holding member 172 that holds a held member 170 fixed to the upper tube 66, and a steering member 36 that is fixed to the holding member 172. The mounting plate 174 is attached to the steering support 36 using a slot 176 provided in the mounting plate 174. In the held member 170 and the holding member 172, elongated holes 178 and 180 are formed, respectively, and a rod 182 passes through them. Although not shown in the drawing, the holding member 172 is made of the rod 182. The held member 170 is clamped. This clamping force prevents the upper tube 66 from being displaced. By operating the operation lever 184, the clamping force can be weakened. When the clamping force is weakened, the movement along the elongated hole 178 of the rod 182 is allowed, so that the upper tube 66 is allowed to move in the axial direction with respect to the lower tube 68 together with the axial movement of the upper shaft 58 relative to the lower shaft 60, and the column section 50 is allowed to expand and contract. Further, the movement of the rod 182 along the elongated hole 180 is allowed, so that the steering force transmission device 12 is allowed to swing around the support shaft 166 inserted through the front bracket 38. That is, the steering force transmission device 12 includes the tilt / telescopic mechanism 186 having such a structure.

  When the driver collides with the steering wheel 10 due to the collision of the vehicle, the B.A.BKT 40 is detached from the steering support 36 and the column section 50 is contracted. The steering force transmission device 12 is provided with an impact absorbing mechanism 187 that absorbs the impact of the secondary collision, and the EA plate 188 is deformed as the column section 50 contracts, thereby causing the impact of the secondary collision. Is effectively absorbed.

<Function of rotation transmission mechanism>
In the present steering force transmission device 12, the two shafts 60, 88 disposed with their axis lines shifted in parallel are connected by the rotation transmission mechanism, so that the rotational phase of the lower shaft 60 is And the rotational phase of the input side shaft 88 shift, and the rotational phase difference, which is the difference between the rotational phases of the two shafts 60 and 88, changes. This will be specifically described with reference to the drawings.

  7 is a cross-sectional view of a circular flange portion 64 of the lower shaft 60 and a roller 122 as an engaging portion that engages with a radial groove 114 formed in the circular flange portion 64 (AA ′ in FIG. 3). Corresponding to a cross-sectional view). FIG. 7A shows a position corresponding to the steering neutral position of the wheel, that is, a state when the steering wheel 10 is in the neutral operation position. FIG. 7B shows a state where the steering wheel 10 is rotated counterclockwise from the neutral operation position. FIG. 7C shows the state when the steering wheel 10 is rotated 90 ° in the clockwise direction from the neutral operation position. FIG. 7D shows the state when the steering wheel 10 is in a position rotated 180 ° in the right or left turning direction from the neutral operation position.

  As can be seen from the figure, when the steering wheel 10 is rotated 90 degrees in the right or left turning direction from the neutral operation position, the lower shaft 60 rotates 90 degrees about its own rotation axis. The shaft 88 does not rotate up to 90 ° about its own rotation axis, and the rotation angle of the input side shaft 88 is less than 90 °. When the steering wheel 10 is further rotated and rotated 180 degrees in the right or left turning direction from the neutral operation position, both the lower shaft 60 and the input side shaft 88 rotate 180 degrees. The relationship between the rotation angle α of the lower shaft 60 and the rotation angle β of the input side shaft 88 is as shown in FIG. 8 when the steering wheel 10 is rotated less than 180 ° from the neutral operation position. The rotation angle β of 88 is smaller than the rotation angle α of the lower shaft 60. When the steering wheel 10 is rotated 180 ° from the neutral operation position, the rotation angle β of the input side shaft 88 is the same as the rotation angle α of the lower shaft 60. It becomes. That is, when the rotational phase of the lower shaft 60 is a specific rotational phase in which the rotational phase of the lower shaft 60 and the rotational phase of the input side shaft 88 coincide with each other, specifically, the rotational angle α of the lower shaft 60 is 0. When the angle is 180 ° or 180 °, the rotation angles α and β are the same, and the rotation phase difference is zero. On the other hand, while the rotation angle α of the lower shaft 60 changes from 0 ° to 180 °, the rotation phase difference gradually increases, and gradually decreases from a certain rotation angle to zero. The gear ratio (dβ / dα) of the two shafts 60 and 88 in this case, that is, the ratio (dβ / dt) of the rotational speed (dβ / dt) of the input side shaft 88 to the rotational speed (dα / dt) of the lower shaft 60. As shown in FIG. 9, dα) changes according to the rotation angle α of the lower shaft 60.

  As can be seen from the figure, when the rotation angle α of the lower shaft 60 is 0 °, the gear ratio (dβ / dα) is the smallest, and the gear ratio (dβ / dα) increases as the rotation angle α of the lower shaft 60 increases. Becomes bigger. That is, in the present steering force transmission device 12, when the operation angle of the steering wheel 10 is small, gentle and stable handling is realized, and as the operation angle of the steering wheel 10 increases, a response with good response is achieved. It is realized. In the present system, the operation range of the steering wheel 10 is limited to about 180 ° left and right from the neutral operation position by an operation range limiting mechanism (not shown).

  Incidentally, e shown on the vertical axis of FIG. 9 indicates the offset of the input side shaft 88 with respect to the offset amount L (FIG. 4) from the rotation axis of the input side shaft 88 at the position where the roller 122 engages with the radial groove 150. This is the ratio of the amount of deviation d (FIG. 4) between the rotation axis and the rotation axis of the lower shaft 60, and affects the operation feeling of the steering wheel 10.

<Rotational transmission when the protrusion is damaged>
In the present steering force transmission device 12, when the steering wheel 10 is rotated, the rotational force of the lower shaft 60 is transmitted to the input side shaft 88 via a protruding portion composed of a roller 122, a pin 118, and the like. The input side shaft 88 is structured to rotate. For this reason, in the steering force transmission device having such a structure, the protruding portion is broken, specifically, the pin 118 or the like is broken, and the protruding portion and the annular plate 116 as the first shaft flange portion are divided. Then, even if the steering wheel 10 is rotated, there is a possibility that the wheel cannot be steered.

  In the present steering force transmission device 12, movable pins 130 and 138 as the movable portions of the first shaft are accommodated in an annular plate 116 provided with a protruding portion, and the protruding portion and the annular plate 116 are divided. Thus, when the lower shaft 60 and the input side shaft 88 are relatively rotated, the movable pins 130 and 138 are engaged with the radial groove 114 so as to function as a second engaging portion. More specifically, as shown in FIG. 5, each of the movable pins 130 and 138 is normally pressed against the end surface of the circular flange portion 64 where the radial groove 114 is not formed, as shown in FIG. Are accommodated in the bottomed holes 132 and 136 respectively. For example, when the steering wheel 10 is rotated in the right turn direction and the projecting portion and the annular plate 116 are separated, the lower shaft 60 and the input side shaft 88 rotate relative to each other, and FIG. As shown, the bottomed hole 132 of one of the two bottomed holes and the opening of the radial groove 114 face each other. At that time, the movable pin 130 accommodated in the one bottomed hole 132 advances into the radial groove 114 by elastic force as shown in FIG. 11 which is a cross-sectional view taken along the line CC ′ of FIG. It engages with the radial groove 114. Thus, when the projecting portion and the annular plate 116 are divided, the movable pin 130 engages with the radial groove 114, and the rotational force of the lower shaft 60 is transmitted to the input side shaft 88 via the movable pin 130. It is. When the steering wheel 10 is rotated in the left turn direction and the projecting portion and the annular plate 116 are separated, the other movable pin 138 engages with the radial groove 114, and the lower The rotational force of the shaft 60 is transmitted to the input side shaft 88 via the movable pin 138.

  Further, even if the protruding portion is divided from the annular plate 116, the protruding portion cannot be discharged from the radial groove 116. For this reason, the protrusion part parted from the annular plate may interfere with the engagement of the movable pins 130 and 138 with the radial groove 114. In the present steering force transmission device 12, a tapered surface is formed at the tip of the movable pins 130 and 138, and the tip is tapered. For this reason, in the present steering force transmission device 12, the movable pins 130 and 138 are easily advanced into the radial groove 114 by pushing away the protruding portion separated from the annular plate by the tapered surface.

  Moreover, the outer diameter of the outer peripheral surface of the movable pins 130 and 138 is made considerably smaller than the outer diameter of the outer peripheral surface of the roller 122 constituting the protruding portion. As described above, by reducing the outer diameter of the movable pins 130 and 138, the movable pins 130 and 138 are placed in the radial groove 114 even when the protruding portion separated from the annular plate exists in the radial groove 114. It is easy to advance into. In addition, the movable pins 130 and 138 as the second engaging portions are used as an auxiliary, and the division between the protruding portion and the annular plate 116 should be repaired as soon as possible. In the present steering force transmission device 12, since the outer diameters of the movable pins 130 and 138 are relatively small, the clearance (gap) between the movable pins 130 and 138 and the pair of side wall surfaces 126 is considerably large. Feels uncomfortable in the rotation operation of the steering wheel 10 due to the large clearance. Therefore, it becomes possible for the driver to quickly detect an abnormality in the vehicle, and it is possible to quickly repair the division between the protruding portion and the annular plate 116.

  Further, the outer diameter of the roller 122 as an engaging portion in a normal state is slightly smaller than the width of the radial groove 116, and there is no clearance (gap) between the roller 122 and the pair of side wall surfaces 126. Slightly present. Although this clearance is slight, there is a possibility that noise, vibration, or the like may occur during traveling due to the clearance, or the driver may feel uncomfortable with the operation feeling of the steering wheel 10. In the present steering force transmission device 12, the movable pins 130 and 138 are normally pressed against the end surface of the circular flange portion 64 where the radial groove 114 is not formed by elastic force, and the lower shaft 60 and the input side shaft 88 are The relative rotation of is suppressed. Therefore, the pressing of the movable pins 130 and 138 against the end face of the circular flange portion 64 suppresses abnormal noise and vibration during traveling caused by the clearance, and reduces the driver's uncomfortable feeling.

It is a mimetic diagram showing a steering system for vehicles provided with a steering force transmission device for vehicles which is an example of a claimable invention. It is sectional drawing which shows the steering force transmission device for vehicles with which the steering system for vehicles of FIG. 1 is provided. It is sectional drawing which shows the EPS section with which the steering force transmission device for vehicles is provided. FIG. 4 is a cross-sectional view taken along line AA ′ shown in FIG. 3. It is sectional drawing in the BB 'line | wire shown in FIG. It is a perspective view which shows the breakaway bracket which hold | maintains the column section with which the steering force transmission device for vehicles is provided. FIG. 4 is a cross-sectional view taken along line AA ′ shown in FIG. 3 when the steering wheel is rotated. It is a graph which shows the relationship between the rotation angle of an operation member side shaft, and the rotation angle of a steering apparatus side shaft. It is a graph which shows the gear ratio of the operating member side shaft and the steering apparatus side shaft which change according to the rotation angle of the operating member side shaft. FIG. 4 is a cross-sectional view taken along line AA ′ shown in FIG. 3 when a protruding portion and a first shaft flange portion are divided. It is sectional drawing in CC 'line shown in FIG.

Explanation of symbols

  10: Steering wheel (steering operation member) 12: Steering force transmission device for vehicle 14: Steering device 18: Output shaft (first shaft) (first shaft main body) 54: Main shaft (second shaft) 58: Upper Shaft (second shaft main body) 62: Shaft main body (second shaft main body) 64: Circular flange (second shaft flange) 86: Output side shaft (first shaft main body) 88: Input side shaft ( 114: radial groove (guide passage) (rotation transmission mechanism) 116: annular plate (first shaft collar) 118: pin (shaft) (protrusion) (engagement portion) (rotation) (Transmission mechanism) 122: Roller (protruding portion) (engagement portion) (rotation transmission mechanism) 126: a pair of side wall surfaces 130: movable pin (movable portion) 134: Coil spring (elastic body) 138: Movable pin (movable part)

Claims (3)

A first shaft having one end connected to one of a steering operation member operated by a driver and a steering device for steering a wheel, and rotatably disposed;
One end is connected to the other of the steering operation member and the steering device, and the rotation axis of the first shaft and the rotation axis of the first shaft are parallel to each other, and the rotation axis is rotatable by a predetermined distance. A second shaft disposed on
(A) at the other end of the first shaft, an engaging portion provided at a position away from the predetermined distance in the radial direction of the first shaft from the rotation axis of the first shaft; The other end of the two shafts is provided so as to extend in the radial direction of the second shaft, and engages with the engaging portion of the first shaft, and the engaging portion in the radial direction of the second shaft. And a guide passage that allows movement, and by rotating one of the first shaft and the second shaft, a rotation phase difference that is a difference between rotation phases of the first shaft and the second shaft is obtained. A vehicle steering force transmission device comprising a rotation transmission mechanism configured to rotate while the other is rotating,
The first shaft is integrated with the first shaft main body at (i) a first shaft main body which is a main body of the first shaft, and (ii) an end of the first shaft main body on the second shaft side. A first shaft flange portion that protrudes from the first shaft main body portion in the radial direction of the first shaft; and (iii) the predetermined axis direction from the rotation axis of the first shaft in the radial direction of the first shaft. At a position away from the distance, the rotation transmission projects from the first shaft flange toward the second shaft in the rotation axis direction that is the direction in which the rotation axes of the first shaft and the second shaft extend. A projection that functions as an engagement portion of the mechanism,
The second shaft is integrated with the second shaft main body at (i) the second shaft main body which is the main body thereof, and (ii) the end of the second shaft main body on the first shaft side. And a second shaft flange that protrudes in the radial direction of the second shaft from the second shaft main body, and (iii) the first shaft of the second shaft flange at the second shaft flange. The rotation transmission is provided on the end surface on the shaft side so as to extend in the radial direction of the second shaft, and has a pair of side wall surfaces into which the protruding portion of the first shaft fits and sandwiches the protruding portion. A radial groove that functions as a guide passage for the mechanism,
The first shaft has a movable portion provided in a state in which the first shaft flange portion is allowed to advance and retract with respect to the end surface of the second shaft flange portion, and the end surface of the movable portion. An elastic body that is elastically deformed with the retreat of
The movable part is
In a state of being retracted with respect to the end surface, the elastic body is pressed against a portion of the end surface of the second shaft flange portion where the radial groove is not open,
When the projecting portion is damaged, the first shaft and the second shaft are rotated relative to each other to advance into the radial groove by the elastic force of the elastic body and function as a second engaging portion. A steering force transmission device for a vehicle. The protrusion has a cylindrical outer peripheral surface in contact with the pair of side wall surfaces;
The movable portion has a cylindrical outer peripheral surface that contacts the pair of side wall surfaces in a state where the movable portion has advanced into the radial groove,
The vehicle steering force transmission device according to claim 1, wherein an outer diameter of the outer peripheral surface of the movable portion is smaller than an outer diameter of the outer peripheral surface of the protruding portion.   The vehicle steering force transmission device according to claim 1, wherein the movable portion has a shape with a tapered tip end portion.

Images