JP6183698B2 - Vehicle steering device - Google Patents

Description

  The present invention relates to a vehicle steering apparatus, and more particularly to a steering apparatus including an electric tilt mechanism that adjusts a steering shaft to a desired inclination angle by an electric motor.

  For example, Japanese Patent Application Laid-Open No. 2004-151620 below describes a steering apparatus including an electric tilt mechanism, which includes a “steering shaft coupled to a steering wheel and a cylindrical column housing that rotatably accommodates and supports the steering shaft. A steering apparatus comprising: a steering column fixed to a vehicle body by a bracket; and a tilt mechanism that adjusts an amount of tilting of the steering column relative to the fixed bracket based on an operation of a tilt motor. A shaft that is driven to rotate, a slide member that slides on the shaft based on the rotation of the shaft, the column housing is connected to the slide member and the fixed bracket, and based on the slide of the slide member, Said And a link mechanism that tilts and moves the aligning column with respect to the fixed bracket, and the link mechanism is disposed on both the left and right sides of the column housing on the radially outer side of the column housing. Document 1 paragraph [0005]).

JP 2006-327374 A

  In the steering device disclosed in Patent Document 1, a link mechanism is used in which the column housing is connected to the slide member and the fixed bracket, and the steering column is tilted with respect to the fixed bracket. The link to be connected is provided regardless of the direction of gravity of the steering column (steering shaft), and the angle of the link with respect to the horizontal plane is not mentioned. The force transmitted through the link to tilt the steering column is preferably set in a direction opposite to the gravity of the steering column. However, in Patent Document 1, a considerable angle is formed with respect to the vertical line. Yes. For this reason, the loss of the driving force for tilting the steering column is large, and the force transmission efficiency is lowered. Therefore, it is necessary to enlarge the electric motor and the speed reducer.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a vehicle steering apparatus including an electric tilt mechanism that has a good force transmission efficiency and can be formed small.

In order to achieve the above object, the present invention connects a main housing that supports a steering shaft so as to be swingable with respect to a vehicle body and a fixed bracket that is fixed to the vehicle body, and adjusts the steering shaft to a desired inclination angle. In the vehicle steering apparatus including the electric tilt mechanism, the electric tilt mechanism is connected to the electric motor, and the driving force conversion mechanism is connected to the electric motor and converts the rotational driving force of the electric motor into a link swing operation. The fixed bracket is supported so as to be rotatable about a first pivot shaft, and is supported to be rotatable about the second pivot shaft with respect to the driving force conversion mechanism. and a first link member which is driven to oscillate about a first pivot axis, said driving force conversion mechanism, the main A tilt screw shaft that is rotatably supported about the third pivot shaft with respect to the wing and is rotationally driven by the electric motor, and is screwed to the tilt screw shaft, and is axially driven according to the rotational drive of the tilt screw shaft And a second link that is rotatably supported about the fourth pivot shaft with respect to the nut member and is rotatably supported about the fifth pivot shaft with respect to the main housing. And the first link member is rotatably supported about the first pivot axis with respect to the fixed bracket and is centered on the second pivot axis with respect to the second link member. The second link member is provided with a lever mechanism in which the second pivot shaft and the fourth pivot shaft swing in opposite directions around the fifth pivot shaft. Form and said first line segment connecting said second pivot axis and the pivot axis is set so that the vertical line at the neutral position of the oscillatory movement of the steering shaft.

  In the above steering apparatus, the first link member may be arranged symmetrically on the left and right sides of the steering shaft.

Since this invention is comprised as mentioned above, there exist the following effects. That is, in the steering apparatus according to the present invention, the electric tilt mechanism is first with respect to the electric motor, the driving force conversion mechanism connected to the electric motor for converting the rotational driving force of the electric motor into the link swing operation, and the fixed bracket. And pivotally supported about the second pivot shaft with respect to the driving force conversion mechanism, and pivoted about the first pivot shaft via the driving force conversion mechanism. A tilt screw shaft that is supported by the main housing so as to be rotatable about the third pivot shaft and is rotationally driven by an electric motor. A nut member that is screwed onto the tilt screw shaft and moves in the axial direction in accordance with the rotational drive of the tilt screw shaft, and is rotatable about the fourth pivot shaft with respect to the nut member. And a second link member supported so as to be rotatable about the fifth pivot axis with respect to the main housing, the first link member being centered on the first pivot axis with respect to the fixed bracket The second link member is rotatably supported and rotatably supported about the second pivot axis, and the second link member has a second pivot axis about the fifth pivot axis. Since the lever mechanism in which the fourth pivot shaft swings in the opposite direction is configured, the steering shaft can be easily adjusted to a desired inclination angle. In particular, since the line connecting the first pivot shaft and the second pivot shaft is set to be a vertical line at the neutral position of the steering shaft swing operation, the neutral position of the steering shaft swing operation is set. In this case, the force transmitted to the first pivot shaft via the driving force conversion mechanism acts in a direction opposite to the gravity of the steering shaft or the like applied to the first pivot shaft, thereby minimizing the loss of driving force. , Efficient force transmission can be performed. In addition, since only the tensile force and the compressive force are applied to the first link member, it is not necessary to increase the size in order to ensure the strength, and a small and lightweight member can be used.

  In the steering apparatus described above, if the first link member is arranged symmetrically on both the left and right sides of the steering shaft, a reliable and smooth swinging operation can be ensured without generating a twisting force.

1 is a side view of a steering device according to an embodiment of the present invention. 1 is a cross-sectional view of a steering device according to an embodiment of the present invention. It is a side view explaining the force transmission condition of the electric tilt mechanism part in one Embodiment of this invention. It is a side view which shows the rake-up state by the steering device which concerns on one Embodiment of this invention. It is a side view which shows the rake-down state by the steering device which concerns on one Embodiment of this invention. It is a side view of the steering device concerning other embodiments of the present invention.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. 1 and 2 show an overall configuration of a steering apparatus according to an embodiment of the present invention. A main housing 2 that supports a steering shaft 1 with respect to a vehicle body B so as to be swingable about a swing center (C). The fixed bracket 3 that is fixed to the vehicle body B is connected via an electric tilt mechanism MT, and the steering shaft 1 is adjusted to a desired inclination angle according to the operation thereof, and the operation position of the steering wheel W is adjusted. Has been. The steering shaft 1 according to this embodiment includes a cylindrical upper shaft 1a having a steering wheel W connected to a rear end portion thereof, and a lower shaft 1b spline-coupled to the front end portion of the upper shaft 1a. Via the main housing 2. The upper shaft 1a and the lower shaft 1b are coupled so as to be relatively movable in the axial direction, and the front end portion of the lower shaft 1b is connected to a turning mechanism (not shown). The steering mechanism is driven in accordance with the operation of the steering wheel W and is configured to steer a steered wheel (not shown) via a wheel steering mechanism (not shown).

  The electric tilt mechanism MT of the present embodiment includes an electric motor 5, a driving force conversion mechanism TR that is connected to the electric motor 5 and converts the rotational driving force of the electric motor 5 into a link swing operation, and the driving force conversion mechanism TR. The first link member 11 is driven. The first link member 11 is supported so as to be rotatable about the first pivot axis P1 with respect to the fixed bracket 3, and is supported so as to be rotatable about the second pivot axis P2 with respect to the driving force conversion mechanism TR. And is driven to swing about the first pivot axis P1.

  A line segment connecting the first pivot shaft P1 and the second pivot shaft P2 is set to be a vertical line (indicated by N in FIG. 1) at the neutral position of the swinging operation of the steering shaft 1. . That is, the force transmitted to the first pivot shaft P1 via the driving force conversion mechanism TR at the neutral position of the swinging operation of the steering shaft 1 causes the gravity of the steering shaft 1 or the like applied to the first pivot shaft P1. It is set to act in a direction opposite to the gravity on the vertical line (N) that coincides with the direction. In FIG. 1, H indicates a horizontal plane, and θv indicates a mounting angle of the steering shaft 1 with respect to the horizontal plane (H).

  As shown in FIG. 1, the driving force conversion mechanism TR of the present embodiment includes a tilt screw shaft 6 that is rotatably supported about a third pivot shaft P3 with respect to the main housing 2 and is rotationally driven by an electric motor 5. A nut member 7 that is screwed onto the tilt screw shaft 6 and moves in the axial direction in accordance with the rotational drive thereof, and is supported by the nut member 7 so as to be rotatable around the fourth pivot shaft P4. The second link member 12 is supported by the housing 2 so as to be rotatable about a fifth pivot axis P5. The second link member 12 of the present embodiment is a V-shaped member and constitutes a bell crank mechanism. The second pivot shaft P2 is centered on the fifth pivot shaft P5 in accordance with the axial movement of the nut member 7. And the fourth pivot shaft P4 swings in the same direction.

  Thus, in the present embodiment, the first link member 11 is supported so as to be rotatable about the first pivot axis P <b> 1 with respect to the fixed bracket 3, and the second link member 12 has the second link member 12. The line segment connecting the first pivot axis P1 and the second pivot axis P2 is supported by the vertical axis (N) at the neutral position of the swinging operation of the steering shaft 1. It is set to be. The tilt screw shaft 6 is formed with a trapezoidal screw, and the nut member 7 is also called a tilt nut or a tilt slider.

  As shown in FIG. 2, the first link member 11 is symmetrically disposed on both the left and right sides of the steering shaft 1, and the first link member 11 is provided on the pair of legs 3 a and 3 a of the fixed bracket 3 having a π-shaped cross section. The link member 11 is supported so as to be rotatable about the first pivot axis P1. The second link member 12 has an H-shaped cross section, and the first link member 11 is supported by the pair of arms 12a and 12a so as to be rotatable around the second pivot axis P2, respectively. A nut member 7 is interposed between the pair of leg portions 12b, 12b, and is supported so as to be rotatable about the fourth pivot shaft P4. Although not shown, the electric motor 5 is connected to the tilt screw shaft 6 via a speed reduction mechanism (for example, a worm shaft and a worm wheel), and the output torque of the electric motor 5 is appropriately adjusted so that the nut member 7 is connected. Is transmitted to.

  Thus, when the electric motor 5 is rotationally driven, the tilt screw shaft 6 is rotationally driven (centered on the shaft), and the nut member 7 (together with the tilt screw shaft 6) is rotated in response to the rotational drive. It moves in the axial direction of the tilt screw shaft 6 while rotating around the axis P3. Accordingly, the second link member 12 swings about the fifth pivot shaft P5, and the first link member 11 swings about the first pivot shaft P1, and the main housing 2 (and The column member 4, the steering shaft 1 and the steering wheel W are swung around the swing center (C), and the steering wheel W is moved in the vertical direction of the vehicle body.

  In this embodiment, the line segment connecting the first pivot shaft P1 and the second pivot shaft P2 is set to be the vertical line (N) at the neutral position of the swinging operation of the steering shaft 1. The force transmitted to the first pivot shaft P1 via the driving force conversion mechanism TR acts in a direction opposite to the gravity of the steering shaft 1 or the like applied to the first pivot shaft P1. It should be noted that, as in the present embodiment, the entire steering shaft 1 etc. swings and the steering wheel W moves upward is called rake up, and the entire steering shaft 1 etc. swings. The movement of the steering wheel W downward is called rake down, and is distinguished from general tilt up and tilt down.

  In FIG. 3, in order to facilitate the explanation of the above-described force relationship, the second link member 12 is changed, and a line segment connecting the fifth pivot axis P5 and the second pivot axis P2 is set longer than in FIG. It is a thing. In FIG. 3, the thrust in the axial direction with respect to the nut member 7 is F0. In the fourth pivot shaft P4, the perpendicular of the line segment connecting the fourth pivot shaft P4 and the fifth pivot shaft P5 is the third pivot shaft P3. Is the angle formed with respect to the line connecting the fourth pivot axis P4 and θa, the component force on the fourth pivot axis P4 (with respect to the line connecting the fourth pivot axis P4 and the fifth pivot axis P5) The vertical component is F0 · cos θa. Further, the length of the line segment connecting the fourth pivot axis P4 and the fifth pivot axis P5 is La, the length of the line segment connecting the fifth pivot axis P5 and the second pivot axis P2 is Lb, In the second pivot axis P2, the angle formed by the perpendicular of the line segment connecting the second pivot axis P2 and the fifth pivot axis P5 with respect to the line segment connecting the first pivot axis P1 and the second pivot axis P2 Is θb, the component force on the second pivot axis P2 (the component on the line segment connecting the first pivot axis P1 and the second pivot axis P2) is F0 · cos θa · (La / Lb) · cos θb. .

  In the first pivot axis P1, if the angle formed by the line connecting the first pivot axis P1 and the second pivot axis P2 with respect to the vertical line (N) is θc, the first pivot axis P1 The applied vertical component force is F0 · cos θa · (La / Lb) · cos θb · cos θc, which is the lifting force F1 when the steering shaft 1 swings. Therefore, if the angle θc at the neutral position of the swinging operation of the steering shaft 1 is set to be 0 °, the lifting force F1 is maximized. The values of La, Lb, θa, and θb are set to appropriate values according to the mounted vehicle. For example, in the present embodiment, unlike FIG. 3, La <Lb is set as shown in FIG.

  As described above, the force applied to the first pivot shaft P1 at the neutral position of the swing operation of the steering shaft 1 becomes the lifting force F1 directly used for the tilt operation. Since the line connecting the first pivot axis P1 and the second pivot axis P2 forms an angle θc with respect to the vertical line (N), the lifting force F1 is a cosine component (cos θc) of F0 · cos θa · (La / Lb) · cos θb. ) Therefore, if the angle θc at the neutral position of the swinging operation of the steering shaft 1 is set to 0 °, that is, the line segment connecting the first pivot axis P1 and the second pivot axis P2 is the vertical line (N). If set so, the force applied to the first pivot shaft P1 can be used as the lifting force F1 as it is, and only the tensile force and the compressive force are applied to the first link member 11. It becomes. In the present embodiment, since the angle θc at the neutral position of the swing operation of the steering shaft 1 is set to 0 °, the first pivot shaft P1 and the second pivot at the uppermost position and the lowermost position. Although the line segment connecting the axes P2 forms a slight angle with respect to the vertical line (N), these are negligible angles, and the loss of driving force can be minimized.

  Next, the operation of the electric tilt mechanism MT configured as described above will be described. First, when the electric motor 5 is rotationally driven (for example, forward rotation), the nut member 7 is moved along the tilt screw shaft 6 along with the tilt screw shaft 6 (along with the tilt screw shaft 6) about the third pivot shaft P3. And rotating in the axial direction in the direction approaching the third pivot axis P3. Accordingly, the second link member 12 swings about the fifth pivot shaft P5, and the first link member 11 swings about the first pivot shaft P1. As a result, the main housing 2 (and the column member 4, the steering shaft 1 and the steering wheel W) swings (rakes up) counterclockwise about the swing center (C), and the operation position of the steering wheel 1 is As shown in FIG. 4, the uppermost position is inclined upward from the neutral position (indicated by a two-dot chain line) about the swing center (C) by an angle α and forms an angle θru with respect to the horizontal plane (H).

  On the other hand, when the electric motor 5 is rotationally driven in the opposite direction, the nut member 7 rotates along with the third pivot shaft P3 (along with the tilt screw shaft 6) in accordance with the rotational motion. It moves axially in a direction away from the third pivot axis P3. Accordingly, the second link member 12 swings about the fifth pivot shaft P5, and the first link member 11 swings about the first pivot shaft P1. As a result, the main housing 2 (and the column member 4, the steering shaft 1 and the steering wheel W) swings (rakes down) clockwise around the swing center (C), and the operation position of the steering wheel 1 is As shown in FIG. 5, the lowermost position is inclined downward from the neutral position (indicated by a two-dot chain line) about the swing center (C) by an angle β and forms an angle θrd with respect to the horizontal plane (H).

  Thus, in the steering device of the present embodiment, the steering shaft 1 can be adjusted to a desired inclination angle. In particular, a line segment connecting the first pivot shaft P1 and the second pivot shaft P2 is set to be a vertical line (N) at the neutral position of the swinging operation of the steering shaft 1, and the steering shaft 1 At the neutral position of the swing operation, the force transmitted to the first pivot shaft P1 via the driving force conversion mechanism TR acts in a direction opposite to the gravity of the steering shaft 1 or the like applied to the first pivot shaft P1. Therefore, the loss of driving force can be minimized and efficient force transmission can be performed. Moreover, since only the tensile force and the compressive force are given to the 1st link member 11, it is not necessary to make it large in order to ensure intensity | strength, and a small and lightweight member can be used. Furthermore, since the first link member 11 is disposed symmetrically on both the left and right sides of the steering shaft 1, a reliable and smooth swinging operation can be ensured without generating a twisting force.

  FIG. 6 shows a steering apparatus according to another embodiment of the present invention. In this embodiment, the second link member 12x provided to the driving force conversion mechanism TR is a rod-shaped member, and a lever mechanism is configured. The second pivot shaft P2 and the fourth pivot shaft P4 are configured to swing in opposite directions around the fifth pivot shaft P5 in accordance with the axial movement of the nut member 7. Since other configurations are the same as those of the above-described embodiment, substantially the same members are denoted by the same reference numerals and description thereof is omitted.

  The driving force conversion mechanism TR may be configured differently from the link mechanism shown in FIGS. Moreover, it is good also as a structure further equipped with the telescopic mechanism with respect to the steering apparatus shown in said FIG.1 and FIG.6. For example, an electric telescopic mechanism (not shown) is provided in addition to the electric tilt mechanism MT described above, so that the column member 4, the steering shaft 1, and the steering wheel W move integrally with the main housing 2 in the axial direction. The steering wheel W can be adjusted to a desired position in the longitudinal direction of the vehicle body.

B Body MT Electric tilt mechanism TR Driving force conversion mechanism P1 First pivot shaft P2 Second pivot shaft P3 Third pivot shaft P4 Fourth pivot shaft P5 Fifth pivot shaft 1 Steering shaft 2 Main housing 3 Fixed bracket 4 Column member 5 Electric motor 6 Tilt screw shaft 7 Nut member 11 First link member 12 Second link member

Claims (2)

In a steering apparatus for a vehicle provided with an electric tilt mechanism that connects a main housing that swingably supports a steering shaft to a vehicle body and a fixed bracket that is fixed to the vehicle body, and adjusts the steering shaft to a desired inclination angle. The electric tilt mechanism includes an electric motor, a driving force conversion mechanism that is connected to the electric motor and converts a rotational driving force of the electric motor into a link swing operation, and a first pivot shaft with respect to the fixed bracket. And is supported rotatably about the second pivot shaft with respect to the driving force conversion mechanism, and swings about the first pivot shaft via the driving force conversion mechanism. and a first link member which is driven into the driving force conversion mechanism, the middle third pivot axis relative to the main housing A tilt screw shaft that is rotatably supported by the electric motor, a nut member that is screwed to the tilt screw shaft and moves in the axial direction in accordance with the rotational drive of the tilt screw shaft, and the nut member And a second link member rotatably supported about a fourth pivot shaft and rotatably supported about the fifth pivot shaft with respect to the main housing. A member is supported to be rotatable about the first pivot axis with respect to the fixed bracket, and is supported to be rotatable about the second pivot axis with respect to the second link member. link member, said the said second pivot axis to a fifth around the pivot axis of the fourth pivot shaft constitute a lever mechanism that swings in the opposite direction, said first pivot axis Steering system for a vehicle segment connecting the serial second pivot axis, characterized in that it is set to be a vertical line at the neutral position of the oscillatory movement of the steering shaft. It said first link member, a steering apparatus for a vehicle according to claim 1, characterized in that it is arranged symmetrically to the right and left sides of the steering shaft.

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