JP3888841B2 - Steering device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a steering device capable of adjusting the position of a steering wheel.
[0002]
[Prior art]
A column that supports the steering shaft connected to the steering wheel, a coupling mechanism that connects the column so as to be swingable about a swinging shaft extending in the left-right direction with respect to the vehicle body, and fixing and releasing the swinging of the column In a steering device including a possible operation mechanism, the position of the steering wheel can be adjusted by swinging the column.
[0003]
As such an operation mechanism, a mechanism having a cam, a cam follower constituted by a pair of rollers, and a manual operation member for relatively rotating the cam and the cam follower around an operation axis has been conventionally used (Japanese Patent Laid-Open No. Hei 6). 219283). The contour surface of the cam is determined so that the cam and the cam follower are relatively displaced in the direction of the operation shaft by the relative rotation of the cam and the cam follower around the operation shaft. The column swing is fixed and released according to the relative displacement of the cam and the cam follower in the operation axis direction.
[0004]
The contour surface of the cam includes a fixed portion that contacts the cam follower when the column is rocked and fixed, a release portion that contacts the cam follower when the column is rocked and unlocked, and the cam follower between the fixed portion and the release portion. And a guide unit for guiding.
[0005]
[Problems to be solved by the invention]
In the contour surface of the cam of the conventional example, the boundary between the guide portion and the fixed portion has an edge shape. Therefore, when the cam follower moves over the edge-shaped boundary in order to fix the swing of the column, the operating force rapidly increases with respect to the operating amount of the operating member and takes a peak value. Therefore, there is a problem that the column cannot be smoothly fixed.
[0006]
An object of the present invention is to provide a steering device that can solve the above-described problems.
[0007]
[Means for Solving the Problems]
The present invention includes a column that supports the steering shaft, a coupling mechanism that connects the column to the vehicle body so as to be swingable, and an operation mechanism that can fix and release the swing of the column. A cam, a cam follower, and a manual operation member that relatively rotates the cam and the cam follower around an operation axis, and the cam and the cam follower are rotated in the operation axis direction by the relative rotation between the cam and the cam follower around the operation axis. The cam contour surface shape is determined such that the cam contour surface is in contact with the cam follower when the column is swing-fixed and the cam follower is unlocked when the column is swing-fixed. A release portion that contacts the guide portion, and a guide portion that guides the cam follower to be displaced between the fixed portion and the release portion. In the steering device in which the column swing is fixed and released according to the relative displacement in the operation axis direction, one end of the guide portion is smoothly connected to the release portion and has a concave curved surface on the cam follower side. The other end of the guide portion is smoothly connected to the fixed portion and is a convex curved surface on the cam follower side, and the curvature of the curved surface at the other end of the guide portion is larger than the curvature of the curved surface at one end, The fixed portion and the release portion are surfaces along the direction of the relative rotation, and the cam follower has a follow-up portion, and is in surface contact with the fixed portion in the swing fixed release state and in the swing fixed release state. A surface in surface contact with the release portion and a convex curved surface connected to the surface are formed in the follower portion, and the guide portion guides the cam follower in a state of guiding the cam follower. Characterized in that the contact with the convex curved surface formed on the part.
According to the configuration of the present invention, when the cam and the cam follower are relatively rotated around the operation shaft by the manual operation member in order to change the column from the rocking / unlocking state to the rocking / fixing state, The cam follower that has been in contact with the release portion on the contour surface of the cam is guided to the fixed portion by the guide portion. The guide portion is smoothly connected to the release portion at one end constituting the boundary with the release portion and has a concave curved surface on the cam follower side, and is smoothly connected to the fixed portion at the other end constituting the boundary with the fixed portion and the cam follower. A convex curved surface is formed on the side. Therefore, it is possible to smoothly change the operating force when operating the operating member, to prevent the operating force from taking a peak value due to an abrupt change, and to fix the column swinging by a smooth operation. Further, when the cam and the cam follower are relatively rotated around the operation axis by the manual operation member in order to change the column from the rocking fixed release state to the rocking fixed state, the rate of increase in the operating force with respect to the operation amount of the operating member is initially Small, large just before the column is in a rocking fixed state. That is, since the manual operation member is initially operated with a small force and finally operated with a large force, it is possible to recognize whether or not the column swing is fixed. Therefore, not only a smooth operation can be performed, but also the operation of the operation member can be prevented from becoming insufficient, and the column swing can be reliably fixed.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
The shock absorbing electric power steering apparatus 1 shown in FIGS. 1 to 3 includes a steering shaft 2, a column 3 that supports the steering shaft 2, and a swing axis O that extends along the left-right direction of the column 3 with respect to the vehicle body. And a manipulation mechanism 10 that can fix and release the swing of the column 3 closer to the steering wheel than the connection mechanism 6.
[0011]
The steering shaft 2 and the column 3 are coaxial with each other, and the axial center thereof is inclined so as to go downward as it goes forward in the state of being attached to the vehicle.
[0012]
A steering wheel (not shown) is connected to one end (upper side in FIGS. 1 and 2) of the steering shaft 2, and a steering gear (not shown) such as a rack and pinion type is connected to the other end. The rotation of the steering wheel is transmitted from the steering shaft 2 to the wheels via the steering gear, whereby the vehicle is steered. The steering shaft 2 has a cylindrical first portion 2a on the wheel side and a second portion 2b on the steering wheel side that is fitted to the first portion 2a so as to be relatively movable in the axial direction. The first portion 2a and the second portion 2b are configured to be non-circular at the fitting position, for example, so that rotation can be transmitted to each other.
[0013]
The column 3 is fitted to a cylindrical first portion 3a fixed to a sensor housing 7a of a torque sensor 7 for detecting an operation torque, and a first portion 3a is fitted to the steering wheel side so as to be capable of axial relative movement. 2 parts 3b. The second portion 3b of the column 3 supports the second portion 2b of the steering shaft 2 so as to be capable of relative rotation about the axis and movable in the axial direction. A steering assist torque corresponding to the steering torque detected by the torque sensor 7 is applied by the steering assist force generating motor 8 attached to the sensor housing 7a. The torque sensor 7 and the steering assist torque applying mechanism can employ known configurations.
[0014]
The connection mechanism 6 has a bracket 21 integrated with the sensor housing 7a, and a support shaft 22 is inserted into the bracket 21 so as to be rotatable about its axis. The support shaft 22 is attached to the vehicle body. As a result, the axis of the support shaft 22 becomes the swing axis O.
[0015]
The operation mechanism 10 includes a first bracket 11 that is a sandwiching member and a second bracket 12 that is a sandwiched member.
The first bracket 11 connects a pair of side walls 11a located on the outer side of the second portion 3b of the column 3, a support part 11b extending from the upper end of each side wall 11a to the left and right, and both support parts 11b. And a connecting portion 11c. Each support portion 11b is formed with a notch 11d that opens on the steering wheel side. The connection member 14 is inserted into each notch 11d. In each support part 11b, the protrusion part inserted in the groove | channel 14a formed in each connection member 14 protrudes from the periphery of each notch 11d. The steering wheel side end portion of the shock absorbing plate 15 is overlaid on each connection member 14. A screw shaft 40 that penetrates each support portion 11 b, each connection member 14, and each shock absorbing plate 15 is implanted in the vehicle body side member 4. Each connection member 14 and each shock absorbing plate 15 are fixed to the vehicle body side by being sandwiched between a nut (not shown) screwed to each screw shaft 40 and the vehicle body side member 4. Resin 16 is filled in a resin filling hole that penetrates the protruding portion of each support portion 11 b, each shock absorbing plate 15, and each connection member 14. Thus, the first bracket 11 is fixed to the vehicle body. Each shock absorbing plate 15 extends from the steering wheel side end portion toward the wheel side, the wheel side end portion is a free end, and a step portion 15a is formed by bending between both ends, and the step portion 15a is supported by each support portion. It is located in the opening 11e formed in the part 11b. The displacement of each shock absorbing plate 15 is regulated by a displacement regulating member 17 attached to each support portion 11b at a portion from the opening 11e toward the wheel. Accordingly, when the driver collides with the steering wheel due to the vehicle colliding with the obstacle, the resin 16 is sheared, the connection between the first bracket 11 and the connection member 14 is released, and the second portion 3b of the column 3 is The second portion 2b of the steering shaft 2 moves in the axial direction relative to the first portion 3a, and the shock absorbing plate 15 is pressed against the inner peripheral surface of the opening 11e. This causes plastic deformation. The impact acting on the driver is absorbed by the shearing of the resin 16, the friction between the first portion 3 a and the second portion 3 b of the column 3, and the plastic deformation of the shock absorbing plate 15.
[0016]
The second bracket 12 has a pair of side walls 12a and a connecting wall 12b that connects the lower ends of both side walls 12a to each other. The second bracket 12 is fixed to the column 3 by welding the upper ends of the side walls 12 a to the second portion 3 b of the column 3. Further, both side walls 12 a of the second bracket 12 are sandwiched between both side walls 11 a of the first bracket 11.
[0017]
Bolts 51 with heads 51 a having left and right axial centers are inserted into both side walls 11 a of the first bracket 11 and both side walls 12 a of the second bracket 12. The insertion opening 11 a ′ of the bolt 51 in the both side walls 11 a of the first bracket 11 allows the bolt 51 to swing relative to the column 3 about the swing axis O and to move relative to the column axis direction. It has an acceptable size. The bolt 51 is inserted so as not to rotate relative to the both side walls 12a of the second bracket 12 in the axial center. For example, the outer periphery of the bolt 51 and the bolt insertion holes 12a ′ of the side walls 12a are non-circular. . Further, a swing guide 52 and an extendable guide 53 are disposed between the head 51 a of the bolt 51 and one side wall 11 a of the first bracket 11. As shown in FIGS. 4 and 5, the swing guide 52 is fixed to one side wall 11a of the first bracket 11 by welding or the like, and has a longitudinal direction along an arc centered on the swing axis O. It has a hole 52a, and a bolt 51 is inserted into the long hole 52a. The telescopic guide 53 is fixed to one side wall 12a of the second bracket 12 via a pin 13, and has a long hole 53a having a longitudinal direction along the axial direction of the column 3, and a bolt 51 is inserted into the long hole 53a. Has been inserted.
[0018]
A nut 54 is screwed onto a bolt 51 protruding from the other side wall 11 a of the first bracket 11. Between the nut 54 and the other side wall 11 a of the first bracket 11, a lever 61 that is a manual operation member, a cylindrical cam 62, and a cylindrical cam follower 63 are fitted to the bolt 51. The lever 61 is fixed so as to rotate along with the cam follower 63, and the cam 62 is fixed to the other side wall 11 a of the first bracket 11. Thus, by rotating the lever 61, the cam 62 and the cam follower 63 rotate relative to the axial center of the bolt 51. The axis of the bolt 51 is an operation axis.
[0019]
The contour surface shape of the cam 62 is determined so that the cam 62 and the cam follower 63 are relatively displaced in the operation axis direction due to the relative rotation of the cam 62 and the cam follower 63 around the operation shaft.
[0020]
That is, one end of the cylindrical cam 62 constitutes a plurality of contour surfaces arranged in parallel along the circumferential direction, and each contour surface is in the swinging fixed state of the column 3 shown in FIG. 3 and FIG. A fixed portion 62 a that contacts the cam follower 63, a release portion 62 b that contacts the cam follower 63 when the column 3 is in the swinging fixed release state as shown in FIG. 6B, and a fixed portion 62 a when the cam follower 63 is rotated relative to the cam 62. And a release portion 62b, and a guide portion 62c for guiding so as to be displaced. The fixing portion 62a, the guide portion 62c, and the release portion 62b on each contour surface are arranged in parallel along the circumferential direction of the cam in this order. In the operation axis direction, the fixed portion 62a is disposed closer to the cam follower 63 than the release portion 62b, and the fixed portion 62a and the release portion 62b are connected by the guide portion 62c. The cam follower 63 has a plurality of follower portions 63a in contact with the cam contour surfaces. When the cam 62 and the cam follower 63 are relatively rotated by the operation of the lever 61, each follower 63a moves along the cam contour surface, so that the cam 62 and the cam follower 63 are relatively displaced in the operation axis direction. Since the distance between the head 51a of the bolt 51 and the nut 54 is kept constant, the second bracket by the side walls 11a of the first bracket 11 according to the relative displacement of the cam 62 and the cam follower 63 in the operation axis direction. Twelve tightening and untightening are performed. That is, when the lever 61 is rotated in one direction, the second bracket 12 is tightened by the first bracket 11 to swing the column 3 around the swing axis O and the second portion 3b is pivoted with respect to the first portion 3a. Directional movement is fixed. When the lever 61 is rotated in one direction and displaced to the position indicated by a two-dot chain line in FIG. 1, the rocking and the axial movement are fixed by releasing the tightening, and the position of the steering wheel can be adjusted. The protrusion 61a formed on the lever 61 abuts against a stopper 66 formed on the first bracket 11, whereby the rotation of the lever 61 is restricted.
[0021]
In each cam contour surface, one end of the guide portion 62c that forms a boundary with the release portion 62b is smoothly connected to the release portion 62b and has a concave curved surface R1 on the cam follower 63 side. In addition, the other end of the guide portion 62c constituting the boundary with the fixed portion 62a is smoothly connected to the fixed portion 62a and has a convex curved surface R2 on the cam follower 63 side. The curvature of the curved surface R2 constituting the contour surface of the cam 62 at the other end of the guide portion 62c is larger than the curvature of the curved surface R1 constituting the contour surface of the cam 62 at one end. In the present embodiment, the contour surface of the cam 62 in the guide portion 62c is along the cycloid curve as viewed from the operation axis direction.
[0022]
According to the above-described configuration, when the cam 62 and the cam follower 63 are relatively rotated around the operation shaft by the lever 61 in order to change the column 3 from the rocking fixed release state to the rocking fixed release state, the column 3 rocking fixed release state The cam follower 63 that has been in contact with the release portion 62b on the contour surface of the cam 62 is guided to the fixed portion 62a by the guide portion 62c. The guide portion 62c is smoothly connected to the release portion 62b at one end that constitutes the boundary with the release portion 62b, and has a concave curved surface R1 on the cam follower 63 side, and the fixed portion at the other end that constitutes the boundary with the fixed portion 62a. It is connected to 62a smoothly and is a convex curved surface R2 on the cam follower 63 side. Therefore, the operating force can be smoothly changed when the lever 61 is operated, the peak value due to the abrupt change of the operating force can be prevented, and the swing of the column 3 can be fixed by the smooth operation. .
In addition, since the curvature of the curved surface R2 is larger than the curvature of the curved surface R1, the cam 61 and the cam follower 63 are moved around the operation axis by the lever 61 in order to change the column 3 from the rocking / unlocking state to the rocking / fixing state. When the relative rotation is performed, the rate of increase of the operation force with respect to the operation amount of the lever 61 is initially small and increases immediately before the column 3 is in the swinging fixed state. As a result, the lever 61 is initially operated with a small force and finally operated with a large force, so that it is possible to recognize whether or not the swing of the column 3 is fixed. That is, the relationship between the operation amount and the operation force at the time of the fixed operation is that the operation force increases rapidly with respect to the operation amount as shown in (1) of FIG. On the other hand, according to the above configuration, as shown in FIG. 7 (2), the increase rate of the operation force with respect to the operation amount is small at first, the increase rate increases immediately before fixing, and the operation force does not take a peak value. Smoothly changes and maximizes. Therefore, not only a smooth operation can be performed, but also the operation of the lever 61 can be prevented from being insufficient, and the swing of the column 3 can be reliably fixed.
Furthermore, since the change rate of the operating force with respect to the operation amount of the lever 61 changes according to the shape of the contour surface of the cam 62, the contour surface of the cam 62 is viewed along the cycloid curve when viewed from the operation axis direction. Thus, the degree of freedom in selecting the change rate is large, and the contour surface of the cam 62 can be easily designed.
[0023]
The present invention is not limited to the above embodiment. For example, the sandwiching member may be fixed to the column, and the sandwiched member may be fixed to the vehicle body.
[0024]
【The invention's effect】
According to the present invention, in a steering device capable of adjusting the position of a steering wheel by swinging a column, the swinging of the column is fixed by a smooth operation to prevent the operation from being insufficient and to ensure that the column is The swing can be fixed, the degree of freedom in selecting the change rate of the operating force can be increased, and the design can be facilitated.
[Brief description of the drawings]
FIG. 1 is a side view of a steering apparatus according to an embodiment of the present invention. FIG. 2 is a partially broken plan view of the steering apparatus according to an embodiment of the present invention. 4 is a view taken along line IV in FIG. 3. FIG. 5 is a cross-sectional view taken along line VV in FIG. 4. FIG. 6A is a view showing a cam and a cam follower when the column is swinging fixed. FIG. 7 is a diagram showing a cam and a cam follower in a state where the rocking is fixed to be released. FIG. 7A is a diagram showing a relationship between an operation amount and an operation force of an operation member in a conventional steering device, and FIG. The figure which shows the relationship between the operation amount of the operation member in the steering device of form, and operation force
2 Steering shaft 3 Column 6 Connection mechanism 10 Operation mechanism 61 Lever (manual operation member)
62 Cam 62a Fixing part 62b Release part 62c Guide part 63 Cam follower O Oscillating shaft R1 Concave curved surface R2 Convex curved surface

Claims (1)

A column that supports the steering shaft;
A coupling mechanism for pivotally coupling the column to the vehicle body,
An operation mechanism capable of fixing and releasing the swing of the column,
The operation mechanism includes a cam, a cam follower, and a manual operation member that relatively rotates the cam and the cam follower around an operation axis.
The contour surface shape of the cam is determined so that the cam and the cam follower are relatively displaced in the direction of the operation axis by the relative rotation between the cam and the cam follower around the operation axis.
The contour surface of the cam includes a fixed portion that contacts the cam follower when the column is rocked and fixed, a release portion that contacts the cam follower when the column is rocked and unlocked, and the cam follower between the fixed portion and the release portion. And a guide part that guides so as to be displaced,
In the steering device in which the swing of the column is fixed and released according to the relative displacement of the cam and the cam follower in the operation axis direction,
One end of the guide portion is smoothly connected to the release portion and a concave curved surface on the cam follower side,
The other end of the guide portion is smoothly connected to the fixed portion and is a convex curved surface on the cam follower side,
The curvature of the curved surface at the other end of the guide is larger than the curvature of the curved surface at one end,
The fixed portion and the release portion are surfaces along the direction of the relative rotation,
The cam follower has a follower,
A surface that is in surface contact with the fixed portion in the rocking / fixed release state and that is in surface contact with the release portion in the rocking / fixed release state and a convex curved surface that is continuous with the surface are formed in the follower portion,
The steering device according to claim 1, wherein the guide portion is in contact with a convex curved surface formed in the following portion in a state in which the cam follower is guided.

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