JP2013123950A - Vehicular steering device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicular steering device more accurately suppressing vibrations of a steering wheel.SOLUTION: The vehicular steering device transmits rotating motion of the steering wheel to steered wheels via a steering shaft. Here, an effective length adjusting mechanism 40 is provided for varying the effective length of a torsion bar 31 provided in the middle of a column shaft 3 which is a component element of the steering shaft.

Description

  The present invention relates to a vehicle steering apparatus that transmits rotational movement of a steering wheel to steered wheels via a steering shaft.

  Since the steering wheel of a vehicle is a part that is always gripped by the driver when driving the vehicle, the vibration tends to be sensitively detected by the driver. Therefore, since the influence of the vibration of the steering wheel on the riding comfort of the vehicle is large, various vehicle steering devices capable of reducing the vibration of the steering wheel have been proposed. As one of this type of vehicle steering apparatus, the one described in Patent Document 1 is provided with a vibration sensor in the steering wheel, and when vibration of the steering wheel is detected through this vibration sensor, an actuator provided in the steering wheel. Therefore, damping force is applied to the steering shaft. Thereby, for example, when vibration from the road surface is transmitted to the steering shaft and the steering wheel vibrates, vibration of the steering wheel is suppressed by a vibration damping force applied from the actuator to the steering shaft. Therefore, the ride comfort of the vehicle can be improved.

Japanese Patent Laid-Open No. 61-218474

  As described above, if the damping force is applied to the steering shaft when the vibration of the steering wheel is detected, the vibration of the steering wheel can surely be suppressed. However, for example, if the frequency of vibration transmitted from the road surface to the steering shaft via the steered wheels is close to the natural frequency of the steering upper part made up of elements such as the steering shaft and steering wheel, a resonance phenomenon occurs and the steering wheel A large vibration occurs. When such a resonance phenomenon occurs, it is difficult to sufficiently suppress the vibration of the steering wheel only by applying a damping force to the steering shaft, so there is still room for improvement.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a vehicle steering apparatus that can more accurately suppress vibration of a steering wheel.

  In order to solve the above-mentioned problem, the invention according to claim 1 is provided in the middle of the steering shaft in a vehicle steering apparatus that transmits the rotational motion of the steering wheel of the vehicle to the steered wheels via the steering shaft. The gist is to provide an effective length adjusting mechanism capable of changing the effective length of the torsion bar.

  According to this configuration, the spring constant of the torsion bar can be changed by changing the effective length of the torsion bar (the length of the portion actually involved in twisting) by the effective length adjusting mechanism. It is possible to change the natural frequency of the steering upper part composed of elements such as a wheel and a steering shaft. Therefore, if the effective length of the torsion bar is changed by the effective length adjusting mechanism when the above-described resonance phenomenon occurs, the natural frequency at the upper part of the steering can be shifted from the resonance frequency, thereby suppressing the resonance phenomenon. be able to. Therefore, it is possible to more appropriately suppress the vibration of the steering wheel.

  In this case, as in the second aspect of the invention, the effective length adjusting mechanism includes a vibration sensor that detects vibration of the steering wheel, and detects vibration of the steering wheel through the vibration sensor. It is effective to adopt a configuration in which the effective length of the torsion bar is changed by the effective length adjusting mechanism. Accordingly, the natural frequency of the upper part of the steering can be changed while accurately detecting the vibration of the steering wheel based on the resonance phenomenon, so that the vibration of the steering wheel can be more accurately suppressed.

  According to a third aspect of the present invention, in the vehicle steering apparatus according to the first or second aspect, the effective length adjusting mechanism has a portion that engages with the torsion bar and has a shaft that is engaged with the torsion bar. The torsion bar is effective by changing a length of a portion in which the torsion bar and the slide member are engaged by relative movement of the slide member with respect to the torsion bar. The gist is that the length is changed.

  According to this configuration, since the torsion bar and the slide member are engaged with each other, they rotate integrally. Further, in the portion where the torsion bar and the slide member are engaged, these members are integrated, and the rigidity of the slide member is added to the torsion bar, so that the torsion bar is hardly twisted. Therefore, if the slide member is moved relative to the torsion bar in the axial direction, the length of the region where the torsion bar is less likely to be twisted can be changed, so that the effective length of the torsion bar can be easily changed. It becomes possible. In this case, as in the invention described in claim 4, in the invention described in claim 3, the torsion bar is provided with a plurality of pins protruding radially outward in the axial direction, and the slide member Is formed with a slot that extends in the axial direction and into which the plurality of pins are inserted, and the effective length adjusting mechanism is disposed in the slot by relative movement of the slide member with respect to the torsion bar. It is effective to adopt a configuration in which the length of the portion where the torsion bar and the slide member are engaged is changed by changing the number of pins. Accordingly, the length of the portion where the torsion bar and the slide member are engaged can be easily changed, so that the invention according to claim 3 can be easily realized.

  A fifth aspect of the present invention is the vehicle steering apparatus according to any one of the first to fourth aspects, wherein the steering shaft includes the steering shaft based on a twist amount of the torsion bar and a spring constant thereof. A torque sensor for detecting a torque acting on the torsion bar is provided, and when the effective length of the torsion bar is changed by the effective length adjusting mechanism, the spring constant of the torsion bar is corrected according to the changed effective length. Is the gist.

  According to the configuration, when the effective length of the torsion bar is changed by the effective length adjusting mechanism, the spring of the torsion bar used when detecting the torque acting on the steering shaft according to the changed effective length. Since the constant is corrected, it is possible to appropriately detect the torque acting on the steering shaft.

  According to the vehicle steering apparatus of the present invention, vibration of the steering wheel can be more accurately suppressed.

1 is a block diagram showing a schematic configuration of an embodiment of a vehicle steering apparatus according to the present invention. (A) is a front view which shows the front structure of the periphery of the torsion bar provided in the middle of the steering shaft about the steering apparatus for vehicles of the embodiment. (B) is sectional drawing which shows the cross-section along the AA line of (a). The perspective view which shows the perspective structure of the effective length adjustment mechanism about the steering apparatus for vehicles of the embodiment. (A), (b) is the front view and sectional drawing which show the operation example about the steering device for vehicles of the embodiment. The flowchart which shows the process sequence about the process which controls operation | movement of the effective length adjustment mechanism by the steering apparatus for vehicles. (A) is a front view which shows the front structure of the periphery of the torsion bar provided in the middle of the steering shaft about the other example of the steering device for vehicles concerning this invention. (B) is sectional drawing which shows the cross-section along the BB line of (a).

  Hereinafter, an embodiment of a vehicle steering apparatus according to the present invention will be described with reference to FIGS. First, with reference to FIG. 1, the outline | summary of the steering apparatus for vehicles concerning this embodiment is demonstrated.

  As shown in FIG. 1, in this vehicle steering apparatus, when the steering wheel 1 is operated by the driver, the steering shaft 2 rotates based on the steering force. The steering shaft 2 has a structure in which an intermediate shaft 4 and a pinion shaft 5 are sequentially connected to a column shaft 3 assembled to the steering wheel 1. Among these, a gear box 6 that converts the rotation of the steering shaft 2 into a linear motion in the axial direction of the rack shaft 7 is connected to the lower end portion of the pinion shaft 5. Then, the axial movement of the rack shaft 7 is transmitted to the steered wheels 9 via the tie rods 8 connected to both ends thereof, so that the steered angle of the steered wheels 9, that is, the traveling direction of the vehicle is changed.

  The vehicle steering apparatus according to the present embodiment is a power steering apparatus 10 in which an assist force is applied to the column shaft 3. The power steering apparatus 10 includes an electric motor 11 coupled to the column shaft 3 via a gear mechanism 12, and transmits the rotation of the electric motor 11 to the column shaft 3 via the gear mechanism 12. Thereby, the motor torque is applied to the steering shaft 2 as an assist force, and the operation of the steering wheel 1 is assisted.

  On the other hand, this vehicle steering apparatus is provided with various sensors for detecting the operation amount of the steering wheel 1 and the state quantity of the vehicle. For example, the steering wheel 1 is provided with a vibration sensor 20 for detecting the vibration. In addition, the vibration sensor 20 is comprised by the acceleration sensor etc., for example. Further, the column shaft 3 is provided with a torque sensor 21 for detecting a torque acting on the steering shaft 2 as the steering wheel 1 is operated, that is, a steering torque. The torque sensor 21 actually detects the twist amount of the torsion bar 31 provided in the middle of the column shaft 3, and the spring constant is determined by the twist amount of the torsion bar 31 detected through the torque sensor 21. The steering torque can be obtained by multiplying by Ktb. Further, the vehicle is provided with a vehicle speed sensor 22 for detecting the speed of the vehicle.

  And the output of each sensor 20-22 is taken in into the control apparatus 13 comprised centering on the microcomputer. The control device 13 performs calculation processing for obtaining the steering torque by multiplying the amount of twist of the torsion bar 31 detected through the torque sensor 21 by the spring constant Ktb, and also through the obtained steering torque and the vehicle speed sensor 22. A target torque that is a target value of the assist force of the electric motor 11 is set based on the detected vehicle speed. Then, the current supplied to the electric motor 11 is feedback-controlled so that the assist force applied from the electric motor 11 becomes the target torque.

  By the way, in such a vehicle steering device, as described above, for example, the frequency of vibration transmitted from the road surface to the steering shaft 2 via the steered wheels 9 is a steering wheel composed of elements such as the steering wheel 1 and the steering shaft 2. Resonance may occur when close to the upper natural frequency. On the other hand, the natural frequency f at the upper part of the steering can be easily obtained by the following equation (1) based on the spring constant Ktb of the torsion bar 31. “Jst” indicates the moment of inertia at the top of the steering wheel.

f = 1 / 2π√ (Ktb / Jst) (1)
That is, if the spring constant of the torsion bar 31 can be changed, the natural frequency at the upper part of the steering changes, so that the resonance phenomenon can be suppressed. In this embodiment, paying attention to this point, in order to change the spring constant of the torsion bar 31, the effective length that can change the effective length that is the length of the portion actually involved in the torsion bar 31. An adjustment mechanism 40 is provided on the column shaft 3.

  Next, the structure of the effective length adjusting mechanism 40 will be described in detail with reference to FIGS. FIG. 2A shows a front structure around the torsion bar 31 of the column shaft 3, and FIG. 2B shows a cross-sectional structure taken along line AA in FIG. It is shown. FIG. 3 shows a perspective structure of the effective length adjusting mechanism 40. 2 and 3, the illustration of the torque sensor 21 is omitted for convenience. The central axis of the column shaft 3 is indicated by an axis m.

  As shown in FIGS. 2 (a) and 2 (b), the torsion bar 31 has a shape having large-diameter portions 31b and 31c at both ends of a small-diameter portion 31a formed longer, mainly based on the application of torque. The small diameter portion 31a is elastically twisted and deformed. In addition, an input shaft 3b assembled to the steering wheel 1 and an output shaft 3c assembled to the intermediate shaft 4 are connected to the large diameter portions 31b and 31c via pins or the like (not shown). The input shaft 3b, the output shaft 3c, and the torsion bar 31 constitute the column shaft 3.

  On the other hand, in the small diameter portion 31a of the torsion bar 31, two pin holes 31d and 31e penetrating in the radial direction are formed side by side in the axial direction. The pin hole 31d is disposed closer to the large diameter portion 31b than the pin hole 31e. Further, the lower end portion of the input shaft 3b is disposed between the pin hole 31d and the pin hole 31e, and a pin hole 31f is formed at a position corresponding to the pin hole 31d of the torsion bar 31. The first pin 41 is inserted into the pin hole 31d of the torsion bar 31 and the pin hole 31f of the input shaft 3b, and the second pin 42 is inserted into the pin hole 31e of the torsion bar 31. Yes. The effective length adjustment mechanism 40 of the present embodiment includes the first and second pins 41 and 42, a cylindrical slide coupling (slide member) 43 into which the torsion bar 31 is inserted, and a slide coupling 43. And two yokes (magnetic bodies) 44 and 45 fixedly arranged with a predetermined gap in the direction of the axis m.

  Among these, the slide coupling 43 is formed with a pair of elongated holes 43a and 43b into which both end portions of the first pin 41 are respectively inserted. The long holes 43a and 43b have an opening on the bottom surface of the slide coupling 43, and are formed so as to extend upward from the opening in the direction along the axis m. A permanent magnet 48 is attached to the upper portion of the slide coupling 43 and is magnetized so that the surfaces facing the yokes 44 and 45 become N poles. The position of the slide coupling 43 is held at the position shown in FIGS. 2A and 2B by the attractive force acting between the permanent magnet 48 and the yokes 44 and 45. And when the slide coupling 43 moves to the position shown to Fig.4 (a), (b), both the 1st and 2nd pins 41 and 42 are inserted in the long holes 43a and 43b.

  As shown in FIGS. 2A and 2B, coils 46 and 47 are wound around the yokes 44 and 45, respectively. Accordingly, the yokes 44 and 45 function as electromagnets based on energization of the coils 46 and 47.

  In the effective length adjusting mechanism 40 having such a structure, when the slide coupling 43 is located at the position shown in FIGS. 2A and 2B, the input shaft 3 b is operated based on the operation of the steering wheel 1. When torque is applied to the input shaft 3b, the input shaft 3b, the torsion bar 31, and the slide coupling 43 rotate together via the first pin 41. Therefore, in the small diameter portion 31a of the torsion bar 31, the portion from the lower end portion to the first pin 41 is elastically deformed. Therefore, the effective length of the torsion bar 31 is the length (first 1 effective length) L1. At this time, the spring constant of the torsion bar 31 is the first spring constant K1 corresponding to the first effective length L1.

  On the other hand, when a current is passed from one end 46a, 47a to the other end 46b, 47b of each of the coils 46, 47, the lower end portions of the yokes 44, 45 are magnetized to the N pole. A repulsive force acts between 48 and the yokes 44 and 45. Due to the repulsive force, the slide coupling 43 moves away from the yokes 44 and 45 to the position shown in FIGS. 4 (a) and 4 (b). And if the slide coupling 43 moves to the position shown to Fig.4 (a), (b), electricity supply to the coils 46 and 47 will be interrupted | blocked. When the slide coupling 43 moves to the position shown in FIGS. 4A and 4B, the attractive force acting between the permanent magnet 48 of the slide coupling 43 and the yokes 44, 45 is greater than the weight of the slide coupling 43. Therefore, the slide coupling 43 is held at the position shown in FIGS. 4 (a) and 4 (b). As a result, the portion where the torsion bar 31 and the slide coupling 43 are engaged changes from the first pin 41 only to the first and second pins 41 and 42. In this case, when torque is applied to the input shaft 3 b based on the operation of the steering wheel 1, the input shaft 3 b, the torsion bar 31, and the slide coupling 43 are integrally rotated via the first and second pins 41 and 42. In the portion where the torsion bar 31 and the slide coupling 43 are engaged, that is, the portion extending from the first pin 41 to the second pin 42, the torsion bar 31 and the slide coupling 43 are integrated, and the torsion bar 31 is integrated. Since the rigidity of the slide coupling 43 is added, the torsion bar 31 is difficult to twist. Therefore, in the small diameter portion 31a of the torsion bar 31, the portion from the lower end portion to the second pin 42 is elastically deformed. Therefore, the effective length of the torsion bar 31 is the length (first 2 (effective length of 2) L2. At this time, the spring constant of the torsion bar 31 is the second spring constant K2 corresponding to the second effective length L2. Since the value of the spring constant of the torsion bar 31 is inversely proportional to its length, the second spring constant K2 is larger than the first spring constant K1.

  On the other hand, when the slide coupling 43 is located at the position shown in FIGS. 4A and 4B, currents flow from the other ends 46b and 47b of the coils 46 and 47 to the one ends 46a and 47a. Since the lower end portions of the yokes 44 and 45 are magnetized to the south pole, an attractive force acts between the permanent magnet 48 of the slide coupling 43 and the yokes 44 and 45. Then, by this suction force, the slide coupling 43 is attracted to the yokes 44 and 45 and returns to the position shown in FIGS. 2 (a) and 2 (b). As a result, the spring constant of the torsion bar 31 returns to the spring constant K1 corresponding to the first effective length L1.

By the way, the relationship of the following formula (2) is established between the first and second effective lengths L1 and L2 and the first and second spring constants K1 and K2.
K1 × L1 = K2 × L2 (2)
On the other hand, when the spring constant of the torsion bar 31 is the first spring constant K1 as illustrated in FIGS. 2A and 2B, the natural frequency f1 at the upper part of the steering is obtained from the above equation (1). It is obtained as in the following formula (3).

f1 = 1 / 2π × √ (K1 / Jst) (3)
Further, as illustrated in FIGS. 4A and 4B, when the spring constant of the torsion bar 31 is the second spring constant K2, the natural frequency f2 at the upper part of the steering is obtained from the above equation (1). It is calculated as the following formula (4).

f2 = 1 / 2π × √ (K2 / Jst) (4)
Here, when the formula (2) is substituted into the formula (4), the formula (4) can be modified as follows.

f2 = 1 / 2π × √ ((K1 · L1 / L2) / Jst)
= 1 / 2π × √ (K1 / Jst) × √ (L1 / L2)
= F1 × √ (L1 / L2)
Therefore, when the slide coupling 43 is moved from the position shown in FIGS. 2 (a) and 2 (b) to the position shown in FIGS. 4 (a) and 4 (b), the natural frequency at the upper part of the steering is √ (L1 / L2) can be changed by a factor of two.

  On the other hand, in the present embodiment, energization of the coils 46 and 47 is controlled by the control device 13 shown in FIG. 1 through a drive circuit (not shown). That is, the control device 13 controls the operation of the effective length adjustment mechanism 40 by controlling the energization of the coils 46 and 47. Next, a process for controlling the operation of the effective length adjusting mechanism 40 executed through the control device 13 will be described in detail with reference to FIG. The process shown in FIG. 5 is actually repeatedly executed with a predetermined calculation cycle.

  As shown in FIG. 5, in this process, it is first determined whether or not the steering wheel 1 is vibrating through the vibration sensor 20 (step S1). Specifically, when the vibration sensor 20 is configured by an acceleration sensor, it is determined that the steering wheel 1 is vibrating when the acceleration detected through the vibration sensor 20 is equal to or greater than a predetermined value. When the steering wheel 1 is vibrating (step S1: YES), the effective length of the torsion bar 31 is changed to an effective length different from the current effective length through the effective length adjusting mechanism 40. (Step S2). Specifically, when the effective length of the torsion bar 31 is set to the first effective length L1, it is changed to the second effective length L2. When the effective length of the torsion bar 31 is set to the second effective length L2, the torsion bar 31 is changed to the first effective length L1. Next, as a process of step S3, the value of the spring constant Ktb used when calculating the steering torque based on the twist amount of the torsion bar 31 detected through the torque sensor 21 is a value corresponding to the changed effective length. It is corrected to. Specifically, when the effective length of the torsion bar 31 is set to the second effective length L2 in the process of step S2, the second spring whose spring constant Ktb corresponds to the second effective length L2 Set to constant K2. When the effective length of the torsion bar 31 is set to the first effective length L1 in the process of step S2, the spring constant Ktb is set to the first spring constant K1 corresponding to the first effective length L1. Is set.

On the other hand, when the predetermined vibration is not generated in the steering wheel 1 (step S1: NO), the control device 13 ends this series of processes.
According to such a configuration, when the steering wheel 1 vibrates due to a resonance phenomenon, this is detected and the effective length of the torsion bar 31 changes, so that the natural frequency at the upper part of the steering deviates from the resonance frequency. Therefore, since the resonance phenomenon can be suppressed, the vibration of the steering wheel 1 can be more accurately suppressed.

  Further, when the effective length of the torsion bar 31 is changed by the effective length adjusting mechanism 40, the spring constant of the torsion bar 31 used in the calculation of the steering torque is corrected according to the changed effective length. . For this reason, it becomes possible to detect a steering torque appropriately.

As described above, according to the vehicle steering apparatus of the present embodiment, the following effects can be obtained.
(1) The effective length adjusting mechanism 40 capable of changing the effective length of the torsion bar 31 is provided. When the vibration of the steering wheel 1 is detected through the vibration sensor 20, the effective length of the torsion bar 31 is changed by the effective length adjustment mechanism 40. As a result, the resonance phenomenon occurring in the upper part of the steering wheel can be suppressed, so that the vibration of the steering wheel 1 can be more accurately suppressed.

  (2) The torsion bar 31 is provided with the first and second pins 41 and 42 protruding outward in the radial direction side by side in the axial direction. The slide coupling 43 is formed with elongated holes 43a and 43b that extend in the axial direction and into which the first and second pins are inserted. In the effective length adjusting mechanism 40, the slide coupling 43 is moved relative to the torsion bar 31 in the axial direction to change the number of pins disposed in the elongated holes 43 a and 43 b, thereby torsion bar 31. The effective length was changed. As a result, the effective length adjusting mechanism according to the present invention can be easily realized.

  (3) When the effective length of the torsion bar 31 is changed by the effective length adjusting mechanism 40, the spring constant Ktb of the torsion bar 31 used when calculating the steering torque is corrected according to the changed effective length. It was decided to. Thereby, even when the effective length of the torsion bar 31 is changed, the steering torque can be detected appropriately.

In addition, the said embodiment can also be implemented with the following forms which changed this suitably.
In the above embodiment, the first and second pins 41 and 42 are provided on the torsion bar 31 to change the length of the portion where the torsion bar 31 and the slide coupling 43 are engaged, and the slide cup In the ring 43, elongated holes 43a and 43b into which the first and second pins 41 and 42 are inserted are formed. Instead, for example, as shown in FIGS. 6A and 6B, the torsion bar 31 is provided with a plate-like engagement member 49 extending in the direction of the axis m. Then, the slide coupling 43 is engaged with the torsion bar 31 by inserting the engagement member 49 into the elongated holes 43 a and 43 b of the slide coupling 43. Even in such a configuration, by moving the slide coupling 43 relative to the torsion bar 31 in the direction of the axis m, the length of the portion where the slide coupling 43 and the engaging member 49 are engaged with each other is increased. It can be changed. Thereby, since the length of the region where twisting is unlikely to occur in the torsion bar 31 can be changed, the effective length of the torsion bar 31 can be changed. In the above embodiment, the effective length adjustment mechanism 40 is arranged at the site on the input shaft 3b side of the torsion bar 31, but instead, it is arranged at the site on the output shaft 3c side of the torsion bar 31. Also good.

  In the above embodiment, the vibration sensor 20 is provided on the steering wheel 1, but instead, for example, a vibration sensor is provided on the steering shaft 2, and based on the vibration of the steering shaft 2 detected through the vibration sensor. The vibration of the steering wheel 1 may be detected. In short, a vibration sensor that directly or indirectly detects vibration of the steering wheel may be provided.

  In the above embodiment, the two pins 41 and 42 are attached to the torsion bar 31, but the number of pins may be three or more. As a result, the spring constant of the torsion bar 31 can be changed to a spring constant other than the first and second spring constants K1, K2, which is effective in suppressing the resonance phenomenon.

  In the above embodiment, when the effective length of the torsion bar 31 is changed by the effective length adjusting mechanism 40, the spring constant of the torsion bar 31 used when calculating the steering torque according to the changed effective length. It was decided to correct Ktb. Instead, for example, an intermediate value between the first spring constant K1 and the second spring constant K2 may be always used as the spring constant Ktb of the torsion bar 31 used when calculating the steering torque.

  In the above embodiment, the present invention is applied to the power steering apparatus 10 that applies assist force to the column shaft 3, but instead, for example, assist force is applied to the pinion shaft 5 and the rack shaft 7. It is also possible to apply to a power steering device. The vehicle steering device according to the present invention can also be applied to a manual type vehicle steering device that does not have a configuration for applying assist force to the steering. In short, any vehicle steering apparatus in which the torsion bar 31 is provided in the middle of the steering shaft 2 can be applied to the vehicle steering apparatus according to the present invention.

  DESCRIPTION OF SYMBOLS 1 ... Steering wheel, 2 ... Steering shaft, 3 ... Column shaft, 3b ... Input shaft, 3c ... Output shaft, 4 ... Intermediate shaft, 5 ... Pinion shaft, 6 ... Gear box, 7 ... Rack shaft, 8 ... Tie rod, DESCRIPTION OF SYMBOLS 9 ... Steering wheel, 10 ... Power steering apparatus, 11 ... Electric motor, 12 ... Gear mechanism, 13 ... Control apparatus, 20 ... Vibration sensor, 21 ... Torque sensor, 22 ... Vehicle speed sensor, 31 ... Torsion bar, 31a ... Small diameter part 31b, 31c ... large diameter portion, 31d-31f ... pin hole, 40 ... effective length adjusting mechanism, 41 ... first pin, 42 ... second pin, 43 ... slide coupling, 43a, 43b ... long hole 44, 45 ... Yoke, 46, 47 ... Coil, 46a, 47a ... One end, 46b, 47b ... The other end, 48 ... Permanent Magnet, 49 ... engaging member.

Claims (5)

In a vehicle steering device that transmits rotational movement of a steering wheel of a vehicle to a steered wheel via a steering shaft,
A vehicle steering apparatus comprising an effective length adjusting mechanism capable of changing an effective length of a torsion bar provided in the middle of the steering shaft. The effective length adjustment mechanism includes a vibration sensor that detects vibration of the steering wheel, and when the vibration of the steering wheel is detected through the vibration sensor, the effective length of the torsion bar is detected by the effective length adjustment mechanism. The vehicle steering device according to claim 1, wherein the vehicle steering device is changed. The effective length adjusting mechanism includes a slide member that has a portion that engages with the torsion bar and is relatively movable in the axial direction with respect to the torsion bar. The vehicle steering apparatus according to claim 1 or 2, wherein an effective length of the torsion bar is changed by changing a length of a portion where the torsion bar and the slide member are engaged. The torsion bar is provided with a plurality of pins protruding radially outward in the axial direction,
The slide member is formed with a slot that extends in the axial direction and into which the plurality of pins are inserted,
The effective length adjusting mechanism is configured such that the torsion bar and the slide member are engaged with each other by changing the number of the pins arranged in the elongated hole by relative movement of the slide member with respect to the torsion bar. The vehicle steering device according to claim 3, wherein the length of the portion is changed. The steering shaft is provided with a torque sensor that detects a torque acting on the steering shaft based on a twist amount of the torsion bar and a spring constant thereof,
5. The spring constant of the torsion bar is corrected according to the changed effective length when the effective length of the torsion bar is changed by the effective length adjusting mechanism. Vehicle steering system.