JP2012076513A - Stabilizer device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a stabilizer device with improved responsiveness.SOLUTION: A stabilizer device 1 adjusts torsional rigidity between stabilizer bars 2, 3 by rotatably driving a screw member 22 with an electric motor 25 and displacing a plunger 21 in an axial direction. A controller 30 for controlling the electric motor 25 controls a position of the plunger 21 at at least 3 levels, hard, medium and soft. When a vehicle body is moving straight and the road condition is not bad, the medium level is selected. When the vehicle body is rolling, the hard level is selected. When a road surface condition is bad, the soft level is selected. When the vehicle body moving straight enters a roll state, a position of the plunger 21 can quickly be adjusted from the medium level to the hard level.

Description

  The present invention relates to a stabilizer device that is mounted on a vehicle such as an automobile and is suitable for suppressing a roll motion of a vehicle body.

  Some vehicles such as automobiles are provided with a stabilizer device in order to stabilize the posture of the vehicle body in a running state such as cornering. In recent years, in addition to the hydraulic stabilizer device that has been developed in the past, development of an electric stabilizer device excellent in mountability has been performed (for example, see Patent Document 1).

JP 2008-120175 A

  The stabilizer device is mounted on a vehicle and used to improve the traveling performance of the vehicle. It is desirable that such a stabilizer device can adjust torsional rigidity (torsional torque) according to road surface conditions, driving conditions, and the like.

  An object of the present invention is to provide a stabilizer device in which torsional rigidity (torsional torque) can be appropriately adjusted according to road surface conditions, driving conditions, and the like.

  In order to solve the above-described problems, a stabilizer device of the present invention includes a first stabilizer bar, a second stabilizer bar, and a variable rigidity portion that adjusts torsional rigidity by connecting the stabilizer bars, and The rigid portion includes a linear motion mechanism that linearly moves according to relative rotation between the first stabilizer bar and the second stabilizer bar, and an urging mechanism that biases the linear motion mechanism in a direction that suppresses the linear motion. A supporting means for supporting the urging mechanism, a holding means for holding the supporting means with a holding force at an arbitrary position, and an actuator for changing the position of the supporting means by applying a force to the supporting means. Control means for controlling the output of the actuator, and the control means is capable of controlling the position of the support means in at least three stages of hardware, medium, and software, The control means controls the vehicle to be medium when the vehicle is running straight and the road surface is not a rough road, to be hard when the vehicle is in a roll state, and to be soft when the road surface on which the vehicle runs is a bad road. It is configured to do.

  According to the present invention, the rigidity (torsion torque) of the stabilizer device can be appropriately adjusted.

1 is an overall configuration diagram schematically showing a vehicle to which a stabilizer device according to an embodiment of the present invention is applied. It is a longitudinal cross-sectional view which shows the structure of the stabilizer apparatus by embodiment. It is a flowchart which shows the control content by the controller in FIG. It is a characteristic diagram which shows the time change of the steering angle, the set load of the urging mechanism, and the current value (motor current) of the actuator.

  Hereinafter, a stabilizer device according to an embodiment of the present invention will be described in detail with reference to FIGS.

  FIG. 1 shows the overall configuration when the stabilizer device 1 is used on the front wheel side and the rear wheel side of the vehicle. The stabilizer device 1 has the following configuration, thereby preventing the vehicle from overturning and improving steering stability. Furthermore, the ride comfort is improved.

  That is, in a state where the vehicle is turning around a corner portion of a road and the inertia force in the roll direction is applied to the vehicle, the stabilizer device 1 provided in front of and behind the vehicle is supplied from a controller 30 described later. Based on the control signal, the vehicle operates to suppress the rolling motion (rolling) of the vehicle, thereby preventing the vehicle from rolling over and improving the steering stability and riding comfort of the vehicle. Depending on the vehicle, the stabilizer device 1 may be provided on one of the front and rear sides of the vehicle.

  The stabilizer device 1 is rotatably attached to the vehicle body side constituting the vehicle through a bush (not shown) at the center in the length direction, and as shown in FIG. 1, both end sides are on the left and right wheel sides. Each is connected (linked). 1 and 2, the stabilizer device 1 includes a first stabilizer bar 2 disposed on one side in the axial direction, and a second stabilizer bar 3 disposed on the other side in the axial direction. The first and second stabilizer bars 2 and 3 are connected to each other, and the variable rigidity portion 5 for adjusting the torsional rigidity between the stabilizer bars 2 and 3 is provided.

  Further, as shown in FIG. 2, the base end portion of the second stabilizer bar 3 becomes an extension portion 4 and is inserted into a casing 6 described later. The extension portion 4 of the second stabilizer bar 3 is formed as a hollow shaft extending in the axial direction at the center portion (axis OO) in the casing 6 and is located on the right side (one side in the axial direction). The shaft portion 4 </ b> A extends to an intermediate portion in the length direction of the casing 6. The other side shaft portion 4B of the extension portion 4 is rotatably supported by the casing 6 via an angular ball bearing 9 described later.

  Further, a rotation-side lamp plate 12 of a ball-and-lamp mechanism 11 described later is integrally provided on the outer periphery of the extension portion 4 between the one-side shaft portion 4A and the other-side shaft portion 4B. The ball and ramp mechanism 11 transmits relative rotation (torsional motion) between the stabilizer bars 2 and 3 with torsional rigidity.

  As shown in FIG. 2, the first and second stabilizer bars 2 and 3 are arranged on the axis OO and are rotatable in a direction twisted about the axis OO with respect to the vehicle body side. It is supported by. The variable rigid portion 5 that connects between the first and second stabilizer bars 2 and 3 includes a casing 6, a ball and ramp mechanism 11, an urging mechanism 17, an extension support member 18, an urging force adjusting mechanism 20, which will be described later. The electric motor 25, the controller 30 and the like are included.

  The casing 6 forming the outer shape of the variable rigid portion 5 is formed as a substantially cylindrical container extending in the axial direction between the first and second stabilizer bars 2 and 3. The casing 6 is formed of a highly rigid metal material or the like, and extends in the axial direction (left, right direction) along the axis OO. The lid body 8 is closed and the gear case 10 to be described later is included.

  Here, the cylindrical body 7 has a flange portion 7A in the left opening, and the right side is closed by the lid portion 7B. Moreover, the base end side of the 1st stabilizer bar 2 is integrally connected to the cover part 7B of the cylindrical body 7 using rotation stopping means, such as spline coupling. As a result, the casing 6 rotates integrally with the first stabilizer bar 2 and rotates relative to the second stabilizer bar 3.

  On the other hand, the lid body 8 located on the other axial side of the cylinder body 7 (left side in FIG. 2) is formed in a stepped cylindrical shape with a highly rigid metal material or the like, and closes the left end portion of the cylinder body 7. is doing. A pair of angular ball bearings 9 which will be described later is provided on the inner peripheral side of the lid 8, and each angular ball bearing 9 supports the second stabilizer bar 3 so as to be rotatable at the position of the extension 4. .

  A gear case 10 is provided on the outer peripheral side of the cylindrical body 7 so as to be closer to the right side in the axial direction. The gear case 10 is formed of a cylindrical body extending in a direction orthogonal to the axis OO, and a worm gear 24B of a reduction gear 24, which will be described later, is accommodated in the gear case 10. In addition, a motor mounting cylinder portion 10A that extends to the right side substantially parallel to the axis OO is provided at an intermediate portion in the length direction of the gear case 10. In this case, the casing 6 of the variable rigidity portion 5 not only houses the ball and ramp mechanism 11 and the urging mechanism 17 inside, but also the casing 6 itself can serve as a transmission member for transmitting torsional force, that is, torsional torque. Function.

  The ball-and-ramp mechanism 11 serving as the linear motion mechanism is accommodated in the casing 6 so as to be located on the left side on the other side in the axial direction of the cylindrical body 7. The ball-and-ramp mechanism 11 is provided in the cylinder 7 so as to be positioned on the other side in the axial direction and rotatable on the rotating side lamp plate 12 relative to the casing 6 and on one side in the axial direction of the rotating side lamp plate 12. And a ball as a rolling element comprising a linear lamp plate 13 fixed to the casing 6 in the rotational direction and a rigid body movably provided so as to relatively roll between the lamp plates 12 and 13. 14 in general. In addition, although the spherical thing is illustrated as the ball | bowl 14, if it rolls between each lamp plate 12 and 13, other rolling elements, such as a tapered roller, may be sufficient.

  Here, the ball and ramp mechanism 11 has an axial direction along the axis OO according to the relative rotational movement between the casing 6 to which the first stabilizer bar 2 is connected (coupled) and the second stabilizer bar 3 ( It moves linearly in the directions indicated by arrows A and B in FIG. The ball and ramp mechanism 11 has a torque transmission coefficient adjusted according to the shape of ramp grooves 12A and 13B, which will be described later, whereby the torsional rigidity of the stabilizer device 1 is adjusted.

  That is, the ball-and-ramp mechanism 11 can change the axial stroke of the linear lamp plate 13 according to the angle when the second stabilizer bar 3 and the casing 6 rotate relative to each other. At that time, the stroke amount with respect to the relative rotation angle can be adjusted by the shape of the ramp grooves 12A and 13B. Further, the reaction force of the urging mechanism 17 is determined by the stroke amount of the linear movement side lamp plate 13, which becomes the torsional torque of the variable rigid portion 5. At that time, the torque can be adjusted by setting the lead angles of the ramp grooves 12A and 13B.

  Here, in the linear motion side lamp plate 13, the guide tube portion 13 </ b> A on the inner peripheral side is supported on the outer periphery of the extension portion 4 via the slide bearing 16. Further, on the outer peripheral side of the linear motion side lamp plate 13, displacement in the rotational direction is constrained by a rolling linear motion guide 15 described later, but is not constrained with respect to axial movement. Thereby, the linear motion side lamp plate 13 can be smoothly moved in the axial direction along the extension portion 4 by the sliding bearing 16 on the inner peripheral side.

  A thrust by an urging mechanism 17 described later acts on the rotation side lamp plate 12 and the linear motion side lamp plate 13, and the balls 14 are respectively applied to the rotation side lamp plate 12 and the linear motion side lamp plate 13 by this thrust. It is pressed against the formed lamp grooves 12A and 13B. The ball and ramp mechanism 11 transmits torque based on the thrust and the shape of the ramp grooves 12A and 13B.

  A plurality of (for example, three) lamp grooves 12A extend in the circumferential direction on the right end surface (front surface) of the rotation-side lamp plate 12 (only one is shown). Here, each lamp groove 12A is formed, for example, curved in an arc shape in the circumferential direction. Each ramp groove 12A is formed as an arcuate groove whose central portion in the length direction becomes the deepest portion and becomes shallow with a desired curvature from the deepest portion toward both ends.

  In addition, three lamp grooves 13 </ b> B are provided on the left end surface (front surface) of the linear motion side lamp plate 13 facing the rotation side lamp plate 12. The three lamp grooves 13B are formed in an arcuate shape that is substantially the same as the lamp groove 12A, with the central part in the length direction being the deepest part, and an arcuate shape that becomes shallower from the deepest part toward both ends. It is formed as a groove.

  Further, for example, three guide grooves 13C (only one is shown) are formed on the outer peripheral side of the linear lamp plate 13 so as to be located between the respective lamp grooves 13B and extend in the radial direction. The rolling linear motion guide 15 is arranged. The three rolling linear motion guides 15 restrict the linear motion side lamp plate 13 from rotating relative to the casing 6 and permit relative displacement (linear motion) in the axial direction of the cylinder 7. is there.

  The rolling linear motion guide 15 is movable in the axial direction in the guide groove 13C so as to face the inner guide piece 15A inserted into the groove bottom side of the guide groove 13C and the inner guide piece 15A in the radial direction. The outer guide piece 15B arranged at the center and a spherical body 15C provided between the guide pieces 15A and 15B so as to be capable of rolling in the axial direction. Further, the outer guide piece 15B is fixed to the inner peripheral surface of the cylindrical body 7 using means such as bolting, press-fitting, and welding.

  Thereby, each rolling linear motion guide 15 rolls the sphere 15C between the inner guide piece 15A fixed to the linear motion side lamp plate 13 side and the outer guide piece 15B fixed to the casing 6 side. The linear movement side lamp plate 13 can be smoothly moved in the axial direction with respect to the casing 6 while restricting relative rotation between the casing 6 and the linear movement side lamp plate 13.

  Further, a sliding bearing 16 is provided on the extension portion 4 of the second stabilizer bar 3 so as to cover the outer periphery of the one-side shaft portion 4A. The slide bearing 16 smoothly moves the linear-side lamp plate 13 in the axial direction with respect to the casing 6, and has a sufficiently small gap so as not to rattle against the inner peripheral surface of the guide tube portion 13A. It comes in sliding contact.

  The ball-and-ramp mechanism 11 as the linear motion mechanism configured as described above pushes the rotation-side lamp plate 12 and the linear motion-side lamp plate 13 toward each other using a biasing force of a biasing mechanism 17 described later. By attaching, normally, the ball 14 is disposed at the deepest part of both the ramp grooves 12A and 13B. As a result, the first stabilizer bar 2 and the second stabilizer bar 3 are urged so that the urging force of the urging mechanism 17 is always the initial angle (the angle at which the vehicle is not inclined in the left and right directions). Is done.

  On the other hand, when the first stabilizer bar 2 (casing 6) and the second stabilizer bar 3 rotate relative to each other about the axis OO, the ramp groove 12A and the ramp groove 13B are relatively relative in the circumferential direction. Therefore, each ball 14 moves from the central portion of each ramp groove 12A, 13B to the end portion side. As a result, the lamp plates 12 and 13 are relatively displaced in directions away from each other in the axial direction according to the inclination of the lamp grooves 12A and 13B. For this reason, the urging force of the urging mechanism 17 pressing the lamp groove 13B toward the lamp groove 12A is increased, and the torsional rigidity at this time can be increased.

  The urging mechanism 17 is provided in the cylindrical body 7 on the right side of the linear lamp plate 13. The urging mechanism 17 is provided on the outer periphery of the extension portion 4 so as to be positioned on one side (right side) in the axial direction of the ball and ramp mechanism 11. The urging mechanism 17 urges the linear movement side lamp plate 13 in a direction to suppress the linear movement of the linear movement side lamp plate 13, and pushes the linear movement side lamp plate 13 toward the rotation side lamp plate 12. It is comprised by the elastic member which generate | occur | produces the pressing force to attach.

  That is, as the elastic member constituting the urging mechanism 17, a member in which a plurality of (e.g., seven) disc springs are alternately stacked as shown in FIG. 2 is used. The urging mechanism 17 formed by connecting the disc springs is arranged so that one end side thereof is in contact with the linear motion side lamp plate 13 and the other end side thereof is in contact with a plunger 21 described later. The urging mechanism 17 applies an urging force (thrust) in the direction indicated by the arrow A to the linearly moving lamp plate 13 of the ball and ramp mechanism 11.

  An extension support member 18 is provided in the cylindrical body 7 so as to be located on the right side which is one end side of the urging mechanism 17. The extension portion support member 18 supports the extension portion 4 of the second stabilizer bar 3 on the center portion (axis OO) side of the cylindrical body 7 constituting the casing 6. The extension support member 18 has a small-diameter bottomed cylindrical support tube 18A, and fan-shaped protrusions 18B that are located at, for example, three locations (only one is shown) in the circumferential direction of the support tube 18A and project from the outer peripheral surface. And leg portions 18C extending outward in the radial direction from the outer peripheral surface of each fan-shaped protrusion 18B.

  In the support cylinder 18 </ b> A constituting the extension portion support member 18, one side shaft portion 4 </ b> A of the extension portion 4 is rotatably inserted via a slide bearing 16. On the other hand, the tips of the three leg portions 18C extending in the radial direction are fixed to the inner peripheral surface of the cylindrical body 7 by means of bolting, press-fitting, welding or the like. Thereby, the extension part support member 18 can support the one side shaft part 4A of the extension part 4 so as to be rotatable at the position of the axis OO, and the angular ball bearing 9 supporting the other side shaft part 4B. The extension part 4 can be supported in a state of being supported between the two.

  Thus, since the extension part 4 is supported by the cylindrical body 7 in the both-sided state, it can be positioned on the axis OO of the cylindrical body 7 and can be rotated at a specified position against bending stress or the like. . Further, since the linear motion side lamp plate 13 is slidably supported on the one side shaft portion 4A of the extension portion 4 via the slide bearing 16, the rotation side lamp plate 12 provided on the extension portion 4 and the linear motion side lamp are provided. The plate 13 can be kept in a parallel state. As a result, each of the lamp plates 12 and 13 can relatively rotate and linearly move while maintaining the coaxiality, and the required characteristics for corresponding to the running state can be obtained accurately.

  A ball bearing 19 is provided in the support cylinder 18 </ b> A of the extension portion support member 18, and the extension portion support member 18 can rotate a small diameter portion 22 </ b> B of a screw member 22, which will be described later, on the axis OO via the ball bearing 19. I support it.

  Furthermore, the extension part supporting member 18 becomes a notch part 18D in which the space between adjacent fan-shaped protrusions 18B and leg parts 18C penetrates in the axial direction, and a push claw 21B of a plunger 21 described later is placed in these notch parts 18D. Is inserted. Thereby, the extension part supporting member 18 fixed to the casing 6 functions as a detent member that restricts the rotation of the plunger 21 while allowing the plunger 21 to move in the axial direction.

  An urging force adjusting mechanism 20 is provided in the cylindrical body 7 on the right side which is one end side of the urging mechanism 17, and the urging force adjusting mechanism 20 moves in the axial direction (directions indicated by arrows A and B). Thus, the urging force of the urging mechanism 17 is adjusted. In the urging force adjusting mechanism 20, push claws 21 </ b> B of a plunger 21 described later are arranged on the outer periphery of the extension portion 4. Further, the urging force adjusting mechanism 20 applies a set load (initial load) having an arbitrary magnitude in the expansion / contraction direction of the urging mechanism 17, for example.

  The urging force adjusting mechanism 20 is configured by a plunger 21, a screw member 22, and the like that can move in the cylindrical body 7 in the axial direction. Here, the plunger 21 has a disc portion 21A as a base, and the surface (left side surface) of the disc portion 21A penetrates each notch portion 18D of the extension portion support member 18 to apply a biasing mechanism. Three push claws 21B extending to the 17 side are provided. The plunger 21 is axially disposed on the linear movement side lamp plate 13 such that each push claw 21B sandwiches the urging mechanism 17 in a preset state (a state where a set load is applied) between the plunger 21B and the linear movement side lamp plate 13. Are provided facing each other. The plunger 21 constitutes a support means that receives and supports the urging force of the urging mechanism 17 (disc spring).

  Furthermore, a screw hole 21C is provided at the center of the disc portion 21A, and the screw hole 21C is formed as a trapezoidal screw, for example. The screw hole 21C of the plunger 21 and the male screw 22C of the screw member 22 to be described later constitute a screw mechanism that converts the rotational motion by the electric motor 25 to be described later into the linear motion of the plunger 21, and the plunger 21 as support means. The holding means by which frictional force is applied is provided to hold the plunger 21 at an arbitrary position, which does not require external energy.

  Thus, since the plunger 21 is screwed into the screw member 22 via the holding means (that is, the screw hole 21C and the male screw 22C) made of a trapezoidal screw, the screw member 22 is attached using the electric motor 25 described later. Unless it is rotationally driven, it is not displaced in the directions indicated by arrows A and B in FIG. 2, and the plunger 21 does not move in the axial direction by the urging force of the urging mechanism 17. In other words, except when the plunger 21 is displaced, the plunger 21 is held at that position by the frictional force of the holding means (screw hole 21C and male screw 22C) made of trapezoidal screws. The power of the electric motor 25 can be prevented from being consumed except when the (set load) is changed.

  The screw member 22 extending in the axial direction from the inner peripheral side of the plunger 21 is formed as a hollow stepped shaft and rotates about the axis OO. That is, the screw member 22 includes a large-diameter portion 22A on one axial side (right side) and a small-diameter portion 22B on the other axial side (left side), and a worm wheel 24A described later is integrally formed therebetween. ing. The screw member 22 is rotatably supported at the tip of the large diameter portion 22 </ b> A by the lid portion 7 </ b> B of the cylindrical body 7 through the thrust ball bearing 23, and the tip of the small diameter portion 22 </ b> B provides the ball bearing 19 with respect to the extension support member 18. It is supported so that it can rotate through.

  On the outer peripheral side of the small diameter portion 22B of the screw member 22, a male screw 22C made of a trapezoidal screw that is screwed into the screw hole 21C of the plunger 21 is formed. The male screw 22C moves the plunger 21 in the axial direction together with the screw hole 21C. The holding mechanism is configured as well as the screw mechanism to be displaced. A worm wheel 24A of a reduction gear 24, which will be described later, is integrally provided on the outer peripheral side of the screw member 22 between the small diameter portion 22B and the large diameter portion 22A.

  Here, the large diameter portion 22 </ b> A of the screw member 22 is rotatably supported in the lid portion 7 </ b> B of the cylindrical body 7 via the thrust ball bearing 23. For this reason, the axial thrust load acting on the screw member 22 is received by the cylindrical portion 7 via the thrust ball bearing 23, and the thrust load acting on the electric motor 25 described later can be suppressed.

  The urging force adjusting mechanism 20 configured in this manner drives the screw member 22 to rotate in the forward and reverse directions by the electric motor 25 and causes the push claws 21B of the plunger 21 to approach the direct acting side lamp plate 13 in FIG. Is linearly displaced in the direction indicated by arrow A and in the direction indicated by arrow B spaced from the linear lamp plate 13. Thereby, each disc spring of the urging mechanism 17 is bent and deformed in the axial direction between the linear lamp plate 13 and each push claw 21B of the plunger 21, and ball-and-and-nose according to the distance (separation dimension) between them. The urging force to the ramp mechanism 11, that is, the spring load (set load) is variably adjusted.

  Therefore, the urging force adjusting mechanism 20 rotationally drives the screw member 22 by the electric motor 25 to displace the plunger 21 in the axial direction, and the urging force (set load, initial load) of the urging mechanism 17 against the ball and ramp mechanism 11. Adjust. For example, when the plunger 21 is located at the position indicated by S in FIG. 2, the set load (initial load) is soft (weak), and when the plunger 21 is located at the position indicated by M in FIG. When the set load is medium (medium) and the plunger 21 is positioned at a position indicated by H in FIG. 2, the set load is adjusted to hard (strong). Thereby, the stabilizer device 1 variably adjusts the torsion torque as the torsional rigidity with respect to the torsion angle between the stabilizer bars 2 and 3 from soft to hard according to the traveling state such as when the vehicle is traveling straight or cornering. can do.

  The speed reducer 24 provided at the position of the gear case 10 includes a worm wheel 24A integrally provided on the outer peripheral side of the screw member 22, a worm gear 24B provided in the gear case 10 and meshed with the worm wheel 24A, and the worm gear. 24B and the rotating shaft 24C which rotates integrally are comprised. The speed reducer 24 decelerates the rotation of the worm gear 24 </ b> B with the worm wheel 24 </ b> A and generates a large rotational torque on the screw member 22.

  An electric motor 25 as an actuator that rotationally drives the speed reducer 24 is housed and provided in a motor mounting cylinder 10 </ b> A of a gear case 10 that is integrally formed with the casing 6. Since this electric motor 25 has its rotational output decelerated by the speed reducer 24 and transmitted to the screw member 22, a small motor having a relatively small output torque can be used. Since the electric motor 25 is disposed at a position away from a portion where a large torque is transmitted between the stabilizer bars 2 and 3 and a portion where a large axial force is applied by the urging mechanism 17, the interior of the electric motor 25 can be removed from rainwater, flying stones, etc. A lightweight case or the like can be used as long as it has sufficient strength to protect.

  The electric motor 25 changes the position (axial position) of the plunger 21 by applying a force (rotational force) to the plunger 21 as a support means. The electric motor 25 is electrically connected to a controller 30 (to be described later) constituting the control means, and the rotation of the electric motor 25 is controlled by the controller 30.

  On the input side of the controller 30, as shown in FIG. 1, a steering angle sensor 26 that detects the steering angle of the steering wheel, a vehicle speed sensor 27 that detects the traveling speed of the vehicle, and a lateral acceleration sensor 28 that detects the lateral acceleration of the vehicle body. The upper and lower acceleration sensors 29 for detecting the vibration acceleration in the upper and lower directions of the vehicle body, road information from the car navigation system, information processed from the image of the in-vehicle camera, and the like are connected, and the actuator of the stabilizer device 1 is connected to the output side. The electric motor 25 is connected.

  The controller 30 constituted by a microcomputer or the like constitutes a control means for controlling the output of the electric motor 25 and, for example, a roll for determining whether or not the vehicle is traveling in a state where it is easy to roll (roll state). The judging means and road surface judging means for judging whether or not the vehicle is traveling on a rough road (running on a normal road such as a paved road).

  Here, the roll determination means determines, for example, whether the vehicle is traveling on a road on which roll behavior occurs, and when the value of the lateral acceleration sensor 28 tends to increase more than a predetermined value on a curved road or the like, When the roll amount is estimated from the value of the steering angle sensor 26 and a roll of a predetermined value or more is estimated, when driving on a corner portion of a road with a car navigation system, or by jumping out with a vehicle-mounted camera or a sudden approach to a preceding vehicle, steering Even when avoidance steering is predicted by the operation, it is determined that the vehicle is traveling on a rolling road. Also, when the vehicle is simply traveling at a high speed of 100 km or more, the roll is generated by a small steering operation. Therefore, it is determined that the vehicle is traveling in such a condition that it is easy to roll even under such conditions. Further, the road surface determination means determines that the road surface is a bad road in a situation where the stabilizer is bad, that is, when the road surface in which the left and right wheels are displaced in the vertical direction with different phases is traveling at a low speed. The straight road is a road other than the roll road, that is, a road on which the vehicle does not roll.

  The controller 30 can control the rotation of the electric motor 25 to adjust the position of the plunger 21 to at least three stages of hardware (H), medium (M), and software (S) as shown in FIG. It is configured. In this case, for example, the controller 30 is hard when the road on which the road is traveling is a roll road with many curves, soft when the road surface is a bad road, and medium when the road surface is a straight road or a normal road. To control.

  For this purpose, the controller 30 includes a storage unit 30A, and the storage unit 30A stores, for example, a processing program shown in FIG. 3 (a processing program for adjusting the set load according to the road surface condition). Then, the controller 30 adjusts the position of the plunger 21 to one of hard (H), medium (M), and software (S) by the electric motor 25 according to the road surface condition where the vehicle travels. The biasing force (set load) of the biasing mechanism 17, that is, the torsional rigidity (torsional torque) between the first and second stabilizers 2 and 3 is adjusted.

  The stabilizer device 1 according to the present embodiment is configured as described above. Next, a process for variably controlling the torsional rigidity of the stabilizer device 1 using the controller 30 will be described.

  For example, when the processing program shown in FIG. 3 is started upon receiving the power supply accompanying the engine start, the controller 30 determines in step 1 whether or not the vehicle is in a roll state. This determination is based on, for example, the vehicle body side acceleration detected directly from the lateral acceleration sensor 28, or the vehicle body estimated from the steering angle detected by the steering angle sensor 26 and the traveling speed detected by the vehicle speed sensor 27. This can be done based on the lateral acceleration on the side. Specifically, when the lateral acceleration exceeds a preset threshold value, it is determined that the vehicle is in a roll state, and when the lateral acceleration is equal to or less than a preset threshold value, the vehicle is not in a roll state (a straight traveling state). Can be determined.

  If it is determined in step 1 that the vehicle is in a roll state, that is, the driver is driving the steering and driving the corner portion of the road, the vehicle body rolls outward. It is necessary to suppress. Then, it progresses to step 2, and the position of the plunger 21 is adjusted to the position of a hard (H) with the electric motor 25. FIG.

  That is, the screw member 22 is rotated by the electric motor 25, and the distance between the linear motion side lamp plate 13 and the pushing claw 21B of the plunger 21 is reduced and brought closer. As a result, the set load (initial load) applied to the urging mechanism 17 becomes large, so that the torsion torque that becomes the torsional force necessary to relatively rotate the first stabilizer bar 2 and the second stabilizer bar 3. Also grows. Therefore, the stabilizer device 1 can suppress the vehicle body from rolling outward by increasing the torsional rigidity between the stabilizer bars 2 and 3, and can stabilize the running posture during cornering.

  On the other hand, when it is determined in step 1 that the vehicle is not in a roll state (for example, in a straight traveling state), the process proceeds to step 3 to determine whether the road surface is a bad road (ordinary road). This determination can be made based on the detection signal of the lower acceleration sensor 29 while detecting the vibration acceleration in the upper and lower directions on the vehicle body side, for example. Specifically, when the vibration acceleration exceeds a preset threshold value a plurality of times within a predetermined time, it is determined that the road surface is a bad road, and when the vibration acceleration is equal to or less than the preset threshold value, it is not a bad road (ordinary It is a road). The criteria for determining the rough road are not absolute, and differ depending on the sports car, luxury passenger car, SUV, off-road vehicle, and also on the setting of the hardness of the stabilizer.

  In such a step 3, when it is determined that the road surface is a rough road, that is, for example, traveling on an uneven road such as an unpaved road, the road surface unevenness is absorbed to ensure a stable traveling posture. There is a need to. Therefore, the process proceeds to step 4 and the position of the plunger 21 is adjusted to the soft (S) position by the electric motor 25.

  That is, the screw member 22 is rotated by the electric motor 25 to increase the distance between the linear motion side lamp plate 13 and the pushing claw 21B of the plunger 21. As a result, the set load (initial load) applied to the urging mechanism 17 is reduced, so that the torsion torque that becomes the torsional force required to relatively rotate the first stabilizer bar 2 and the second stabilizer bar 3. Becomes smaller. Therefore, since the torsional rigidity of the stabilizer device 1 can be reduced, the left and right wheels can be stroked independently according to the unevenness of the road surface (for example, even if one wheel falls into the recess) Only one wheel can be stroked), and a stable running posture and good riding comfort can be obtained.

  On the other hand, if it is determined in step 3 that the road surface is not a bad road (a normal road), the process proceeds to step 5 where the electric motor 25 adjusts the position of the plunger 21 to the medium (M) position. That is, the screw member 22 is rotated by the electric motor 25 so that the separation dimension between the linear motion side lamp plate 13 and the pushing claw 21B of the plunger 21 is medium (between hardware and software).

  As a result, the set load (initial load) applied to the urging mechanism 17 is made larger than that of the software, and the torsional force is required to rotate the first stabilizer bar 2 and the second stabilizer bar 3 relative to each other. The torsional torque is increased to such an extent that the riding comfort required from the vehicle running speed, lateral acceleration, etc. is not deteriorated.

  As described above, according to the present embodiment, the torsional rigidity (set load) of the stabilizer device 1 during normal traveling (when traveling substantially straight and when the road surface is traveling on a normal road) is set to medium (M). Therefore, the torsional rigidity can be quickly adjusted from the medium (M) to the soft (S) or from the medium (M) to the hard (H) when moving from the normal traveling to the roll state or traveling on a rough road. That is, for example, the amount of movement (displacement amount) of the plunger 21 by the electric motor 25 can be reduced when moving from the normal travel to the roll road travel as compared to the conventional technology in which the torsional rigidity during the normal travel is set to be soft. The responsiveness of the stabilizer device 1 can be improved.

  FIG. 4 is a characteristic diagram showing temporal changes in the steering angle, the set load (= position of the plunger 21), and the current value of the electric motor 25 when the vehicle moves from the normal running to the roll state. Note that the set load and motor current in FIG. 4 indicate the characteristic line according to the present embodiment using a solid line 31 and the characteristic line according to the conventional technique using a two-dot chain line 32. Also, T1 is the time when the driver starts operating the steering wheel, T2 is the time when the movement of the plunger 21 is started, and T3 is the time when the movement of the plunger 21 according to the present embodiment is completed. The time point when the movement of the plunger is finished is T4.

  As is clear from FIG. 4, according to the present embodiment in which the set load at the time of normal traveling (when traveling on a straight road on a normal road) is set to medium (M), the set load at the time of normal traveling is set. Compared with the prior art set to soft (S), the distance and time until the plunger 21 is moved to hard (H) can be shortened, and the responsiveness can be improved accordingly. As a result, the set load can be quickly adjusted to hard (H) even when a sudden steering operation is performed, for example, during emergency steering. For this reason, the roll of a vehicle body can be suppressed stably also at the time of emergency steering, and a vehicle can be turned stably. In addition, the straight path (straight-running state) in the present invention does not indicate only when traveling on a straight road, but refers to a case where the vehicle is not in a roll state, and includes a case where a curve is made at a low speed.

  In the case of the present embodiment, since the set load during normal running is set to medium (M), the set load is set to hard (H) as shown by the motor current characteristic line in FIG. The starting current I1 at the time of adjustment becomes larger than the starting current I2 in the case of the prior art in which the set load during normal running is set to soft (S). However, since the time until the set load is adjusted to the hard (H) (the time for the plunger 21 to move to the hard position, that is, the driving time of the electric motor 25) can be shortened, the total power consumption can be reduced compared to the conventional technology. Can be small. After the plunger 21 reaches the target position (hard), the plunger 21 is held at that position by the holding force (frictional force) of the holding means (screw hole 21C and male screw 22C) made of trapezoidal screws (electric motor). The position of the plunger 21 can be held without consuming 25 current).

  Further, since the responsiveness can be improved as compared with the conventional technique, for example, even if the reduction ratio of the reducer 24 is increased by the amount that the responsiveness can be afforded, the responsiveness similar to the conventional technique can be ensured. When the reduction ratio is increased in this way, the maximum current of the electric motor 25 can be reduced, and the electric motor 25 can be further miniaturized and the harness for supplying power to the electric motor 25 can be thinned. .

  In the above-described embodiment, the process of step 1 shown in FIG. 3 shows a specific example of the roll determination means, and the process of step 3 shows a specific example of the road surface determination means.

  In the embodiment described above, the lateral acceleration sensor 28 detects the determination performed by the roll determination means (determination of whether or not the roll state is established) (from the steering angle of the steering angle sensor 26 and the traveling speed of the vehicle speed sensor 27). The case of performing based on lateral acceleration information (estimated) has been described as an example. However, the present invention is not limited to this, and it may be determined whether or not the roll state is established using other information such as the amount of expansion and contraction of the suspension device. In short, any information (state quantity) may be used as long as it can be determined whether or not the vehicle is rolling.

  In the above-described embodiment, an example is given in which the determination made by the road surface determination means (determination of whether or not the road is rough) is performed based on the vibration acceleration information detected in the upper and lower directions by the upper and lower acceleration sensors 29. And explained. However, the present invention is not limited to this, for example, based on the information from the car navigation system (for example, GPS information), the lateral acceleration information of the vehicle body detected from the lateral acceleration sensor, the road surface information from the in-vehicle camera, etc. It may be determined whether or not the vehicle is traveling on the road.

  Since the stabilizer device 1 has a great lateral acceleration reduction effect, it is preferable to determine whether or not the road is a rough road based on, for example, GPS information or lateral acceleration information, as compared with the case where the stabilizer device 1 is based on the upper and lower acceleration information. . In any case, when it is determined that the vehicle is traveling on a rough road, a good riding comfort can be obtained by adjusting the set load to soft (S).

  In the above-described embodiment, the case where the set load is adjusted to software (S) when the road surface determination unit determines that the road surface is a bad road has been described as an example. However, the present invention is not limited to this. For example, when it is determined by the speed determination means that the traveling speed is low (extremely low speed, for example, 20 km or less, more preferably 10 km or less), the set load is adjusted to soft (S). You may make it do.

  In the above-described embodiment, the case where the set load (the position of the plunger 21) is controlled in three stages of hardware, medium, and software according to the road surface condition has been described as an example. However, the present invention is not limited to this. For example, the control may be performed in a plurality of stages including four stages or linearly. That is, it is possible to determine the vehicle running condition and the road surface condition more finely and to control the set load (the position of the support means) more finely according to the determination. The medium of the present invention is a value between hardware and software, and may be set close to hardware or may be set close to software depending on vehicle specifications.

  In the above-described embodiment, the case where the determination is made using the roll determination unit and the road surface determination unit and the set load (the position of the plunger 21) is controlled according to the determination result has been described as an example. However, the present invention is not limited to this. For example, the set load (the position of the support means) may be adjusted using other determination means such as a travel speed determination means in addition to the roll determination means and the road surface determination means.

  In the embodiment described above, the case where the urging mechanism 17 is configured by a plurality of disc springs has been described as an example. However, the configuration is not limited to this, and another elastic member such as a coil spring may be used instead of the disc spring.

  Further, in the above-described embodiment, the case where the holding means for holding the position of the plunger 21 is configured by trapezoidal screws (screw holes 21C and male screws 22C) has been described as an example. However, the holding means may be configured by, for example, a ratchet mechanism or a torque diode.

  According to the above embodiment, the torsional rigidity (roll rigidity) at the time of normal traveling (when the road surface is traveling on a normal road in a substantially straight traveling state) is set to medium, so that the roll state or the rough road from the normal traveling is set. When traveling, the torsional rigidity can be adjusted quickly (with less power) from medium to soft or medium to hard, and the response of the stabilizer device can be improved.

  Thereby, for example, when the vehicle is traveling on a rough road, the torsional rigidity is adjusted softly, and a stable traveling posture and good riding comfort can be obtained. In addition, when moving to a normal road or the like, the torsional rigidity is adjusted to medium, and the torsional rigidity can be quickly and quickly adjusted when moving to a roll state or when emergency steering is performed. For this reason, appropriate torsional rigidity according to the road surface condition (traveling condition) can be ensured.

  In the above-described embodiment, the roll state is preferentially determined. However, control may be performed so that road surface determination is prioritized according to vehicle specifications and stabilizer specifications. In the case of a rough road and a roll state, the medium may be maintained.

  In addition, since the responsiveness can be improved compared to the prior art, for example, the reduction ratio of the reducer can be increased by an amount that can provide a responsiveness, and the power consumption of the actuator, the miniaturization, and the harness can be thinned. it can. In other words, by setting the torsional rigidity during normal driving to medium, it is possible to select whether to improve responsiveness or reduce the maximum current by increasing the reduction ratio, thereby increasing design flexibility. Can do.

  Furthermore, according to the embodiment, since the holding means does not require energy from the outside, the power of the actuator (for example, an electric motor) is not consumed when holding the support means at an arbitrary position. Energy saving can be achieved.

DESCRIPTION OF SYMBOLS 1 Stabilizer apparatus 2 1st stabilizer bar 3 2nd stabilizer bar 5 Variable rigidity part 11 Ball and ramp mechanism (linear motion mechanism)
17 Biasing mechanism 21 Plunger (supporting means)
21C Screw hole (holding means)
22 Screw member 22C Male screw (holding means)
25 Electric motor (actuator)
30 controller (control means)

Claims (2)

Comprising a first stabilizer bar, a second stabilizer bar, and a variable rigidity portion for adjusting the torsional rigidity by connecting the respective stabilizer bars;
The variable stiffness portion is
A linear motion mechanism that linearly moves according to relative rotation between the first stabilizer bar and the second stabilizer bar;
A biasing mechanism that biases the linear motion mechanism in a direction to suppress the linear motion;
Supporting means for supporting the biasing mechanism;
Holding means for holding the supporting means at an arbitrary position with holding force;
An actuator for changing the position of the support means by applying a force to the support means;
Control means for controlling the output of the actuator,
The control means can control the position of the support means in at least three stages of hard, medium, and soft,
The control means controls the vehicle to be medium when the vehicle is straight and the road surface is not a bad road, to be hard when the vehicle is in a roll state, and to be soft when the vehicle is running on a rough road. The stabilizer apparatus which becomes a structure which carries out.   The stabilizer device according to claim 1, wherein the holding means does not require external energy.

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