JP5310137B2 - Vehicle suspension system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve practicality for a suspension device provided with a torsion bar spring. <P>SOLUTION: The suspension device includes (A) a torsion bar 66 extending in a vehicle width direction, (B) a pair of arms 68 extending from each of both ends of the torsion bar 66 after intersecting with the bar and jointed to right and left wheel holding members 40, (C) a fixture 70 fixing a center part in an axial direction of the torsion bar 66 to the vehicle body 14 to prohibit rotation of the part, and (D) a pair of actuators 100 respectively disposed on the vehicle body 14 and applying rotating force to each of both ends of the torsion bar 66 and each of the part at a space to the center part. It is configured to suspend the vehicle body 14 with torsion reaction force of the torsion bar 66, and to apply force to each of the right and left wheels 12 and the vehicle body 14 in such a direction as to approach or separate from each other by the rotating force applied to the torsion bar 66 by the pair of actuators 100. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a vehicle suspension device provided with a torsion bar type suspension spring.

  As described in the following patent document, a suspension spring that is a component of a vehicle suspension device is a torsion bar type suspension spring (hereinafter referred to as “torsion bar spring”) that suspends the vehicle body by a torsional reaction force of the torsion bar. May exist). More specifically, the torsion bar spring has one end of the torsion bar fixed to the vehicle body and the other end connected to the wheel, and the torsion bar is twisted around the axis along with the approaching / separating of the wheel and the vehicle body, The wheel and the vehicle body are elastically connected by the torsional reaction force of the torsion bar.

JP-A-5-155225 Japanese Utility Model Publication No. 61-183709 Japanese Utility Model Publication No. 60-72706

  The suspension devices described in Patent Documents 1 and 2 change the torsional reaction force of the torsion bar by adjusting the torsion amount of the torsion bar with a drive source, and change the distance between the vehicle body and the wheel. That is, it is possible to easily adjust the vehicle height. In addition, the suspension device described in Patent Document 3 has an elastic body fixed to the outer periphery of the torsion bar, and the outer peripheral surface of the elastic body is not rotated from the state of rotating with the rotation around the axis of the torsion bar. By switching, it is possible to switch the spring constant of the suspension spring using the circumferential reaction force of the elastic body. These examples of improvement of the suspension device provided with the torsion bar spring are merely examples, but the suspension device provided with the torsion bar spring still leaves room for improvement. Therefore, it is considered that the practicality of the suspension device provided with the torsion bar spring can be improved by making various improvements. This invention is made | formed in view of such a situation, and makes it a subject to provide a highly practical vehicle suspension apparatus.

In order to solve the above-described problems, the suspension device of the present invention includes (A) a torsion bar disposed on a vehicle body along an axis extending in the vehicle width direction, and (B) each of both end portions of the torsion bar. A pair of arms that extend across the torsion bar and are connected to the left and right wheel holding members at the tip, and (C) the central part in the axial direction of the torsion bar is fixed to the vehicle body, A fixture that prohibits rotation; and (D) each (a) a housing that is fixed to the vehicle body and that holds the torsion bar in a rotatable state; and (b) is housed in the housing and is generated by itself. rely on force is assumed to have an electromagnetic motor for applying a rotational force to the torsion bar, and a pair of actuators for imparting a rotational force to each portion between each and the center portion of both end portions of the torsion bar It includes, part and a portion between the other of the central portion and both end portions, is configured to be twisted each twist-reacting force of the torsion bar between one of the central portion and both end portions of the torsion bar In addition to suspending the vehicle body, a rotational force applied to the torsion bar by a pair of actuators applies a force in the direction in which the left and right wheels and the vehicle body approach and separate from each other. The

  The suspension device of the present invention has a relatively simple configuration because both the torsion bar springs corresponding to the left and right wheels are constituted by one torsion bar and one fixture. Further, according to the suspension device of the present invention, a force in a direction in which the pair of actuators approach and separate the vehicle body and each of the left and right wheels is applied via the torsion bar. For example, active control for suppressing the roll amount and pitch amount of the vehicle body can be executed. Due to such advantages, the vehicle suspension device of the present invention is highly practical.

Aspects of the Invention

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

In each of the following items, the combination of items (1) and (2) and a limitation on the configuration of the torsion bar correspond to claim 1, and the technical item of item (3) is added to claim 1. A feature is added to claim 2, a feature to which claim 2 is added the technical features of (4) and (5) is claim 3, and claim 1 is any one of claims 1 to 3. The technical feature of (6) is added to claim 4, and the technical feature of (7) and (8) is added to claim 4 and claim 3 is added.

(1) a torsion bar disposed on the vehicle body along an axis extending in the vehicle width direction;
A pair of arms extending from each of both ends of the torsion bar so as to cross the torsion bar and connected to the left and right wheel holding members at the tip,
A fixing device that fixes a central portion of the torsion bar in the axial direction to the vehicle body and prohibits rotation of the central portion of the torsion bar;
Each provided with a pair of actuators that are disposed on the vehicle body and apply a rotational force to each of the portions between both ends of the torsion bar and the central portion;
The vehicle body is suspended by the torsional reaction force of the torsion bar, and the rotation force applied to the torsion bar by the pair of actuators causes the left and right wheels and the vehicle body to move toward and away from each other. A vehicle suspension device configured to be applied with force.

  In the suspension device described in this section, one torsion bar is fixed to the vehicle body by one fixture at the center thereof, and the left wheel side portion from the center of the torsion bar is the left wheel and the vehicle body. And the portion on the right wheel side of the center portion of the torsion bar is twisted with the approach and separation operation of the right wheel and the vehicle body. That is, in the suspension device described in this section, both the torsion bar springs as suspension springs corresponding to the left and right wheels are configured by only one torsion bar and one fixing tool. The bar spring is integrated into a simple configuration. Incidentally, the suspension device described in this section can be considered as a configuration in which a conventional stabilizer bar is fixed to the vehicle body at the center.

  The “torsion bar” in this aspect is configured such that a portion between the central portion and one of both end portions and a portion between the central portion and the other of the both end portions are twisted respectively. It may be sufficient and it is not limited to one member. For example, it may have a plurality of members, each of which is fixedly connected and configured in a single bar shape. In addition, the “one pair of arms” extending across from both ends of the torsion bar may be a member separate from the torsion bar and fixed to each end of the torsion bar. A rod-shaped member may be bent and formed integrally with the torsion bar.

  In the “fixing device” according to the aspect of this section, the center portion of the torsion bar is fixed to the vehicle body so as to prohibit the rotation around the axis line while being twisted with respect to both ends. A configuration that generates a torsional reaction force for suspension can be employed, and for example, a so-called anchor arm can be employed. The anchor arm can adjust the torsional reaction force of the torsion bar by changing the amount of rotation at the center of the torsion bar, and can easily adjust the distance between the vehicle body and the wheel. is there.

  In addition, the suspension device described in this section is configured such that a rotational force can be applied to each of the portions between the central portion and both end portions of the torsion bar by a pair of actuators. That is, in the suspension device described in this section, the actuator force generated by the actuator can be applied to each of the left and right wheels and the vehicle body via the torsion bar. If the “actuator” is capable of generating an actuator force as a resistance force against the approaching / separating operation between the wheel and the vehicle body, the suspension device described in this section has a function as a shock absorber. In addition, the actuator is a force that positively moves the sprung portion and the unsprung portion, that is, a propulsive force, and a force that prevents the sprung portion and the unsprung portion from relatively moving with respect to external input, that is, a maintaining force. Can also be generated. That is, the suspension device described in this section can execute various controls described in detail later by using various actuator forces generated by the actuator.

(2) Each of the pair of actuators is
A housing fixed to the vehicle body and rotatably held in a state of passing through the torsion bar;
The vehicle suspension device according to (1), further comprising: an electromagnetic motor housed in the housing and applying a rotational force to the torsion bar based on a force generated by itself.

  The mode described in this section is a mode in which the structure of the actuator is embodied, and the mode in which the actuator is provided coaxially with the torsion bar. Therefore, according to the aspect of this section, a relatively compact suspension device is realized.

(3) The torsion bar is
A pair of main bar portions that are coaxial with each other and are disposed in a state in which one end portions thereof are close to each other, and each of the other end portions is provided with the pair of arms,
Each of the pair of main bar portions is externally fitted to the one corresponding to itself, and one end portion of the pair is connected to one end portion of the pair of main bar portions corresponding to itself. A pair of inner cylinders;
Item (1) or (2) which has an outer tube portion fitted to the pair of inner tube portions, and each of its both end portions connected to the other end portion of each of the pair of inner tube portions. The suspension device for a vehicle according to the item).

  The aspect described in this section is an aspect in which the torsion bar is formed so as to extend toward the left and right wheels after being folded inside the outer cylinder portion. In the aspect of this section, not only the main bar part is twisted, but also the inner cylinder part and the outer cylinder part are twisted, and the effect of lengthening the torsion bar is obtained. Therefore, according to the aspect of said 2 term, it becomes possible to ensure the rigidity with respect to the twist of a torsion bar easily. As will be described in detail later, the pair of inner tube portions may have a shape that is folded back inside the outer tube portion. In that case, the torsion bar is moved a plurality of times inside the outer tube portion. It will be in a folded state.

  (4) The vehicle suspension device according to (3), wherein each of the pair of actuators applies a rotational force to each of the pair of main bar portions.

  (5) The vehicle suspension device according to (3) or (4), wherein the fixing tool fixes a part of the outer cylinder portion to the vehicle body.

  The aspect described in the above two items is an aspect in which a relationship with other components included in the suspension device is embodied in an aspect in which a part of the torsion bar is folded back. In the case where the actuator described above is provided coaxially with the torsion bar, from the viewpoint of ensuring rigidity against torsion of the torsion bar, the portion formed to be folded back should be as long as possible. For example, it is desirable that the both ends of the outer cylinder portion be long so as to be close to the housings of the pair of actuators. The modes of the above two terms are effective modes when such a configuration is adopted.

(6) The torsion bar is
A first torsion bar member provided at one end with one of the pair of arms;
A second torsion bar member provided at one end with the other of the pair of arms;
Both end portions are detachably connected to the other end portion of the first torsion bar member and the other end portion of the second torsion bar member to connect the first torsion bar member and the second torsion bar member. The vehicle suspension device according to any one of (1) to (5), including a third torsion bar member to be connected.

  In the aspect described in this section, the torsion bar before assembly is divided into three parts, and the spring constant of the torsion bar spring is changed by changing the third torsion bar member which is an intermediate member among the three members. In addition, the length of the torsion bar in the vehicle width direction can be changed. That is, according to the aspect of this section, it is possible to configure torsion bars corresponding to various vehicles only by changing the third torsion bar member.

  In addition, the aspect which combined the aspect of this term and the aspect formed so that a part of the torsion bar described above may be folded, for example, a part of each wheel side of the pair of main bar portions The first torsion bar member and the second torsion bar member, each having the remaining part of the pair of main bar portions, the pair of inner cylinders, and the outer cylinder, constitute a third torsion bar member This can be achieved.

  (7) The vehicle suspension device according to (6), wherein each of the pair of actuators applies a rotational force to each of the first torsion bar member and the second torsion bar member.

  (8) The vehicle suspension device according to (6) or (7), wherein the fixing tool fixes a part of the third torsion bar member to the vehicle body.

  The aspect described in the above two items is an aspect in which the relationship with other components included in the suspension device is embodied in the aspect in which the torsion bar can be divided into three. According to the former of the above two terms, it is possible to share a pair of actuators in addition to the first torsion bar member and the second torsion bar member for various vehicles. When the actuator described above is provided coaxially with the torsion bar, the other end portions of the first torsion bar member and the second torsion bar member are protruded from the actuator, and the protrusions are allowed to protrude. In such a portion, it can be configured to be connected to each of both end portions of the third torsion bar member.

(9) The vehicle suspension device is
In any one of (1) to (8), an actuator force control device that controls an actuator force generated by each of the pair of actuators is provided to control a rotational force applied to the torsion bar. The vehicle suspension apparatus described.

  According to the aspect described in this section, the actuator force can be controlled, for example, various controls described in the following section can be executed, and the suspension apparatus has a function as a shock absorber and a function as a stabilizer apparatus. Various functions can be exhibited.

(10) The actuator force control device comprises:
The vehicle suspension apparatus according to (9), configured to execute roll suppression control for controlling an actuator force based on a roll moment of the vehicle body in order to suppress a roll amount of the vehicle body caused by turning of the vehicle. .

(11) The actuator force control device comprises:
(9) or (10) is configured to execute pitch suppression control that controls the actuator force based on the pitch moment of the vehicle body in order to suppress the pitch amount of the vehicle body due to vehicle acceleration / deceleration. The vehicle suspension apparatus described.

(12) The actuator force control device includes:
The items (9) to (11) are configured to execute vibration damping control for controlling the actuator force based on the sprung speed in order to dampen the vibration of the sprung corresponding to each of the left and right wheels. The vehicle suspension apparatus according to any one of the above.

  The modes described in the above three items are modes that embody the control for controlling the actuator force. The modes described in the first and second items are modes that make it possible to suppress the inclination of the vehicle body that occurs during vehicle turning and vehicle acceleration / deceleration. According to these modes, for example, active vehicle body posture control can be executed in accordance with vehicle speed, steering angle, lateral acceleration generated in the vehicle body, longitudinal acceleration, and the like. Further, the aspect described in the third item is an aspect in which control based on the so-called skyhook damper theory can be executed. The vibration damping control is a control that comprehensively executes both the control based on the above-described skyhook damper theory and the control based on the pseudo ground hook damper theory that generates a damping force against the vibration of the unsprung part. It may be.

1 is a schematic diagram illustrating an overall configuration of a vehicle including a vehicle suspension device according to a claimable invention. It is a schematic diagram which shows the suspension apparatus for vehicles of FIG. 1 in the viewpoint from the vehicle upper direction. It is a schematic diagram which shows the suspension apparatus for vehicles of FIG. 1 in the viewpoint from the vehicle rear. It is sectional drawing which expands and shows the center part of the torsion bar with which the suspension apparatus for vehicles of FIG. 1 is provided. FIG. 4 is a side view (A-A cross section in FIG. 3) showing a fixture provided in the vehicle suspension device of FIG. 1. It is sectional drawing of the actuator with which the suspension apparatus for vehicles of FIG. 1 is provided. It is sectional drawing which expands and shows the center part of the torsion bar with which the suspension apparatus for vehicles of a modification is provided.

  Hereinafter, embodiments of the claimable invention will be described in detail with reference to the drawings. In addition to the following examples, the claimable invention is implemented in various modes including various modifications and improvements based on the knowledge of those skilled in the art, including the mode described in the above [Mode of Invention]. can do.

<Configuration of suspension device>
FIG. 1 schematically shows a vehicle including a suspension device 10 which is an embodiment of the claimable invention. The vehicle includes two suspension devices 10Fr, four between the front and rear wheels 12FR, FL, RR, RL and the vehicle body 14, corresponding to the front wheels 12FR, FL side and the rear wheels 12RR, RL. 10Rr is disposed. Since the front wheel side suspension device 10Fr that is a steered wheel and the rear wheel side suspension device 10Rr that is a non-steered wheel can be regarded as substantially the same configuration except for a mechanism that allows the wheel 12 to be steered, the description will be simplified. In consideration, the suspension device 10Rr on the rear wheel side will be described as a representative with reference to FIGS. 2 is a plan view of the suspension device 10Rr (viewed from above the vehicle), and FIG. 3 is a front view thereof (viewed from the rear of the vehicle). In the following description, when it is necessary to clarify which of the four wheels corresponds, as shown in the figure, as a subscript indicating the wheel position, the left front wheel, the right front wheel, In some cases, FL, FR, RL, and RR are attached to the left rear wheel and the right rear wheel, respectively. Further, when it is necessary to distinguish the front wheel side and the rear wheel side, Fr and Rr may be attached.

  As shown in FIGS. 2 and 3, the suspension device 10 is of an independent suspension type and is a multi-link type suspension device. The suspension device 10 includes a first upper arm 30, a second upper arm 32, a first lower arm 34, a second lower arm 36, and a toe control arm 38, each of which is a suspension arm as a wheel holding portion. One end of each of the five arms 30, 32, 34, 36, 38 is pivotally connected to the vehicle body 14, and the other end is pivotable to an axle carrier 40 that rotatably holds the wheel 12. It is connected to. With these five arms 30, 32, 34, 36, 38, the axle carrier 40 can move up and down so as to draw a substantially constant locus with respect to the vehicle body 14.

  The suspension device 10 includes a torsion bar spring device 50 in which a pair of suspension springs corresponding to the left and right wheels are integrally formed, and a pair of hydraulic shock absorbers 52 corresponding to the left and right wheels, respectively. I have. As will be described in detail later, the torsion bar spring device 50 suspends the vehicle body 14 by a torsional reaction force of a portion that extends in the vehicle width direction and is generally formed in a rod shape. Each of the pair of hydraulic shock absorbers 52 is disposed between a mount portion 56 constituting a part of the upper part of the spring and a second lower arm 36 constituting a part of the lower part of the spring. A damping force is generated for a relative operation with the second lower arm 36, that is, an approaching / separating operation between the left and right wheels 12 and the vehicle body 14.

  As shown in FIGS. 2 and 3, the torsion bar spring device 50 includes a pair of L-shaped bar members 60 that are generally L-shaped, and one of each of a pair of L-shaped bar members 60 each having both ends. A torsion spring 64 assembled with an intermediate torsion bar member 62 detachably coupled to the end portion is mainly configured. The torsion spring 64 has a torsion bar portion 66 extending generally in the vehicle width direction in a state where the above three members are assembled, and a torsion bar portion 66 integrally extending with the torsion bar portion 66 and extending forwardly of the vehicle. It can be divided into a pair of arm portions 68. That is, each of the pair of L-shaped bar members 60 is a first torsion bar member and a second torsion bar member provided with an arm at one end, and the intermediate torsion bar member 62 is a third torsion bar member.

  More specifically, the torsion bar portion 66 of the torsion spring 64 is rotated around its axis by the anchor arm 70 at the center portion in the vehicle width direction, more specifically, at the center portion of the intermediate torsion bar member 62. It is fixed to the vehicle body 14 in a prohibited state. Further, the torsion bar portion 66 is rotatably held at a position close to the pair of arm portions 68 by a holder 72 fixedly provided on the vehicle body 14 in a state in which rotation around its own axis is allowed. . The distal ends of the pair of arm portions 68 are connected to the second lower arm 36 via the link rod 74.

  FIG. 4 shows an enlarged cross section of the central portion of the torsion spring 64. As shown in the figure, the intermediate torsion bar member 62 is fitted to a pair of main bars 80 arranged coaxially with each other in a state where one end portions thereof are close to each other, and to each of the pair of main bars 80. And a pair of inner cylinders 82 and an outer cylinder 84 fitted around the pair of inner cylinders 82. The intermediate torsion bar member 62 is formed by coupling the central end of each of the pair of main bars 80 and the central end of each of the pair of inner cylinders 82 to each of the pair of inner cylinders 82. The end portion on the wheel side and each of both end portions of the outer cylinder 84 are combined. That is, the intermediate torsion bar member 62 is shaped to be folded back inside the outer cylinder 84 and extend toward the left and right wheels 12. And the front-end | tip part extended toward the left-right wheel 12 of the intermediate | middle torsion bar member 62, ie, the edge part of each wheel 12 side of a pair of main bar part 80, is a pair of L-shaped bar member 60. Serrated with each other (see FIG. 6).

  And the torsion spring 64 is being fixed to the vehicle body in the center part of the said outer cylinder 84 by the anchor arm 70 demonstrated previously, as shown in FIG. More specifically, serrations are provided on the outer peripheral surface of the outer cylinder 84 and the inner peripheral surface of the insertion hole 90 of the anchor arm 70, and the central portion of the outer cylinder 84 is not rotatable with respect to the anchor arm 70. The The anchor arm 70 has a bolt nut 92 provided between the front end portion of the anchor arm 70 extending in a direction intersecting the axis of the outer cylinder 84 and the vehicle body 14, and tightens the bolt nut 92. Thus, the central portion of the outer cylinder 84 is rotated around the axis with respect to both ends of the torsion bar portion 66, and is fixed to the vehicle body 14 in a state where rotation around the axis from that position is prohibited.

  That is, the torsion spring 64 includes a portion on the right wheel 12RR side from the center portion of the torsion bar portion 66 (hereinafter sometimes referred to as “right torsion bar portion 66RR”) and a left wheel 12RL side from the center portion of the torsion bar portion 66. (Hereinafter, sometimes referred to as “left torsion bar portion 66RL”) is twisted, and the vehicle body 14 is suspended by the torsional reaction force. Further, the torsion spring 64 is twisted with the right torsion bar portion 66RR being moved toward and away from the right wheel 12RR and the vehicle body 14, and the left torsion bar portion 66RL is moved toward and away from the left wheel 12RL and the vehicle body 14. It will be twisted with it. Therefore, the torsion bar spring device 50 is configured to independently apply an elastic force between the left wheel 12 and the vehicle body 14 and between the right wheel 12 and the vehicle body 14.

  Note that the twisting of the right torsion bar portion 66RR and the left torsion bar portion 66RL will be described in detail. The intermediate torsion bar member 62 has a shape as shown in FIG. Not only the pair of main bar portions 80 are twisted, but also the pair of inner cylinder 82 and outer cylinder 84 are twisted.

  In addition, the suspension device 10 includes a pair of actuators 100RR and 100RL that apply a rotational force to each of the right torsion bar portion 66RR and the left torsion bar portion 66RL. Each of the pair of actuators 100RR, 100RL is disposed at an end portion on the center side in the vehicle width direction of each of the pair of L-shaped bar members 60. Since each of the pair of actuators 100RR and 100RL has the same configuration, the actuator 100RR corresponding to the right rear wheel is represented by referring to FIG. 6 in consideration of simplification of description. explain.

  The actuator 100 has a housing 110 fixed to the vehicle body 14, and in the housing 110, the L-shaped bar member 60 is rotatably held in a state where the center end portion in the vehicle width direction is penetrated. ing. The actuator 100 includes an electromagnetic motor 112 as a drive source and a differential device 114 that decelerates the rotation of the electromagnetic motor 112 and transmits it to the L-shaped bar member 60 inside the housing 110.

  The electromagnetic motor 112 includes a plurality of coils 120 fixedly arranged on one circumference along the inner surface of the peripheral wall of the housing 110, a hollow motor shaft 122 rotatably held in the housing 110, and the coil 120. And a permanent magnet 124 that is fixedly disposed on the outer periphery of the motor shaft 122. The electromagnetic motor 112 is a motor in which the coil 120 functions as a stator and the permanent magnet 124 functions as a rotor, and is a three-phase DC brushless motor. A motor rotation angle sensor 126 for detecting the rotation angle of the motor shaft 122, that is, the rotation angle of the electromagnetic motor 112 is provided in the housing 110. The motor rotation angle sensor 126 mainly includes an encoder and is used for controlling the actuator 100.

  The differential device 114 includes a wave generator (wave generator) 130, a flexible gear (flex spline) 132, and a ring gear (circular spline) 134. It may be called a “mechanism” or the like. The wave generator 130 includes an elliptical cam and a ball bearing fitted on the outer periphery thereof, and is fixed to one end of the motor shaft 122. The flexible gear 132 has a cup shape in which the peripheral wall portion can be elastically deformed, and a plurality of teeth (400 teeth in the differential device 114) are formed on the outer periphery on the opening side of the peripheral wall portion. The flexible gear 132 is connected to and supported by the L-shaped bar member 60 described above. More specifically, the L-shaped bar member 60 passes through the motor shaft 122, and the flexible gear 132 serving as the output portion of the differential device 114 is provided on the outer peripheral surface of the end portion on the center portion side extending from the motor shaft 122. In a state of penetrating the bottom portion, the bottom portion is connected to the bottom portion by serration coupling so as not to be relatively rotatable. The ring gear 134 is generally ring-shaped and has a plurality of teeth (402 teeth in the differential gear 114) formed on the inner periphery thereof, and is fixed to the housing 110. The flexible gear 132 is elastically deformed into an elliptical shape with a peripheral wall portion fitted on the wave generator 130, and meshes with the ring gear 134 at two positions located in the major axis direction of the ellipse and does not mesh at other positions. It is said that. With such a structure, when the wave generator 130 rotates once (360 degrees), that is, when the motor shaft 122 of the electromagnetic motor 112 rotates once, the flexible gear 132 and the ring gear 134 are relatively rotated by two teeth. .

  From the structure described above, when the motor 112 is driven, the motor force generated by the motor 112 (since the motor 112 is a rotary motor, it can be considered as rotational torque, and thus may be referred to as rotational torque. ), The L-shaped bar member 60 is rotated via the differential device 114, and the torsion bar portion 66 is twisted. The torsional reaction force generated by the torsion is transmitted to the second lower arm 36 via the arm portion 68 and the link rod 74, and the force that pushes the second lower arm 36 down and up with respect to the vehicle body 14, in other words, the wheel 12 It acts as an approaching / separating force that is a force in a direction for approaching and separating the vehicle body 14 from each other. That is, the actuator force that is the force generated by the actuator 100 acts as an approaching / separating force via the torsion spring 64.

  The operation of the suspension device 10 disposed on the front wheel side and the rear wheel side, specifically, the operation of each of the four actuators 100, is a suspension electronic control unit 200 (hereinafter referred to as “ECU 200”) as an actuator force control device. (See FIG. 1). The ECU 200 is connected to four inverters provided corresponding to the motors 112 of the four actuators 100. These inverters are connected to a battery 210 via a converter 208, and power is supplied to a motor 112 of each actuator 100 from a power source including the converter 208 and the battery 210. Since the motor 112 of each actuator 100 is driven at a constant voltage, the amount of power supplied to the motor 112 is changed by changing the amount of supplied current, and the motor 112 has a force corresponding to the amount of supplied current. Will be demonstrated. Incidentally, the supply current amount is changed by each inverter changing the ratio (duty ratio) between the pulse-on time and the pulse-off time by PWM (Pulse Width Modulation).

  The vehicle includes a lateral acceleration sensor 220 that detects lateral acceleration generated in the vehicle body, a longitudinal acceleration sensor 222 that detects longitudinal acceleration generated in the vehicle body, and a vertical acceleration (vertical acceleration) of each mount portion 56 of the vehicle body 14 corresponding to each wheel 12. Acceleration on the four spring acceleration sensors 224 for detecting the steering angle, the operation angle sensors 226 for detecting the steering wheel operating angles, and the four wheels 12 for detecting the respective rotational speeds. A wheel speed sensor 228, a throttle sensor 230 that detects the opening of the accelerator throttle, a brake pressure sensor 232 that detects the master cylinder pressure of the brake, and the like are provided. The sensor and the motor rotation angle sensor 184 described above are provided in the ECU 200. It is connected. The ECU 200 controls the actuator force generated by each actuator 100 based on signals from these switches and sensors.

<Control of suspension system>
i) Outline of Control of Actuator This suspension apparatus 10 is a control based on the so-called skyhook damper theory (hereinafter referred to as the skyhook damper theory) which is a control for attenuating the vibration of the sprung corresponding to each wheel 12 by the ECU 200. (Sometimes referred to as “vibration damping control”), control for suppressing the roll amount of the vehicle body caused by turning of the vehicle (hereinafter, also referred to as “roll suppression control”), and vehicle body caused by vehicle acceleration / deceleration Control for suppressing the pitch amount (hereinafter sometimes referred to as “pitch suppression control”) is executed in parallel. Basically, the actuator force generated by each actuator 100 is independently controlled, and the vibration damping control, roll suppression control, and pitch suppression control are comprehensively executed. Specifically, in the above vibration damping control, roll suppression control, and pitch suppression control, the target actuator force is determined by adding the vibration damping component, roll suppression component, and pitch suppression component, which are the components of the actuator force for each control. The actuator 100 is comprehensively executed by being controlled to generate the target actuator force.

ii) Vibration damping control In the vibration damping control, a vibration damping component F _V of the actuator force is determined so as to generate an actuator force having a magnitude corresponding to the vibration speed in order to attenuate the vibration of the sprung portion. That is, the control is based on the so-called skyhook damper theory. Specifically, the vertical operating speed of the mount 56 of the vehicle body obtained from the sprung vertical acceleration sensor 224 provided on the mount 56 of the vehicle body, that is, the so-called absolute spring speed Vs. Based on this, the vibration damping component F _V is calculated according to the following equation.
F _V = Cs · Vs
Here, Cs is a gain for generating a damping force according to the vertical operation speed of the mount portion 56 of the vehicle body. In other words, Cs can be considered as a damping coefficient for so-called absolute sprung vibration.

iii) Roll restraint control When the vehicle is turning, the roll moment resulting from the turn causes the spring upper part and the unsprung part on the turning inner ring side to be separated from each other, and the spring upper part and the unsprung part on the turning outer ring side are brought closer to each other. It is done. In the roll suppression control, in order to suppress the separation on the turning inner ring side and the approach on the turning outer ring side, the actuator force in the bounce direction is applied to the actuator 100 on the turning inner ring side, and the actuator force in the rebound direction is applied to the actuator 100 on the turning outer ring side. Each is generated as a roll restraining force. Specifically, first, as a lateral acceleration indexing the roll moment received by the vehicle body, an estimated lateral acceleration Gyc estimated based on the steering angle δ of the steering wheel and the vehicle speed v, and a lateral acceleration sensor 220 were measured. Based on the actual lateral acceleration Gyr, a control lateral acceleration Gy ^* , which is a lateral acceleration used for control, is determined according to the following equation.
Gy ^* = K ₁ · Gyc + K ₂ · Gyr (K ₁ , K ₂ : gain)
Such based on the determined control-use lateral acceleration Gy ^*, the roll restrain component F _R is determined according to the following equation.
F _R = K ₃ · Gy ^* (K ₃ : Gain)

iv) Pitch suppression control When a vehicle nose dive occurs during deceleration, such as when the vehicle is braked, the front wheel side spring top and spring bottom are brought closer to each other by the pitch moment that causes the nose dive. The sprung part on the ring side and the unsprung part are separated from each other. In addition, when squat of the vehicle body is generated during acceleration of the vehicle, the sprung moment that generates the squat separates the front wheel spring top and the spring bottom, and the rear wheel spring top and spring bottom. Is approached. In the pitch suppression control, the actuator force is generated as the pitch suppression force in order to suppress fluctuations in the distance between the sprung springs in those cases. Specifically, as longitudinal acceleration indicative of the pitch moment acting on the vehicle body, is employed the actual longitudinal acceleration Gx that is actually measured by the longitudinal acceleration sensor 222, and based on the actual longitudinal acceleration Gx, the pitch restrain component F _P has the following formula Determined according to.
F _P = K ₄ · Gx (K ₄ : Gain)
It should be noted that the pitch suppression control is executed when the throttle opening detected by the throttle sensor 230 or the master cylinder pressure detected by the brake pressure sensor 232 exceeds a set threshold.

v) Target Actuator Force and Motor Operation Control The actuator 100 is controlled based on a target actuator force that is an actuator force that should be generated. In detail, as described above, the vibration damping component F _V of the actuator force, a roll restrain component F _R, the pitch restrain component F _P is determined on the basis of their target actuator is a control target value in accordance with the following equation The force F ^* is determined.
F ^* = F _V + F _R + F _P
Then, the operation control of the motor 112 for generating the target actuator force F ^* determined as described above is performed by the inverter. More specifically, a target duty ratio is determined based on the target actuator force F ^* determined as described above, and a command based on the duty ratio is transmitted to the inverter. The inverter operates the motor 112 to generate the target actuator force F ^* under the appropriate duty ratio.

<Features of this suspension device>
In this suspension device 10, both torsion bar springs as suspension springs corresponding to the left and right wheels are configured by only one torsion spring 64 and one anchor arm 70, and the left and right torsion bar springs are integrated. Thus, the apparatus has a simple configuration. In addition, one torsion spring 64 is formed by connecting three members, a pair of L-shaped bar member 60 and an intermediate torsion bar member 62, and the suspension spring can be obtained simply by changing the intermediate torsion bar member 62. It is possible to change the spring constant and the length in the vehicle width direction. That is, the suspension device 10 can make the L-shaped bar member 60 and the actuator 100 disposed at the end thereof common to various vehicles and change only the intermediate torsion bar member 62. It is possible to configure suspension devices corresponding to these various vehicles.

  As shown in FIG. 4, the intermediate torsion bar member 62 is configured not only to twist the pair of main bar portions 80 but also to twist the pair of inner cylinder 82 and outer cylinder 84. . That is, the torsion spring 64 provides an effect that is longer than the distance from the center portion of the torsion bar portion 66 to its end portion. As a result, the torsion spring 64 has sufficiently secured rigidity against torsion of the torsion bar portion 66.

  Furthermore, the suspension device 10 is configured such that each of the pair of actuators 100 applies a rotational torque to a portion between each of both end portions of the torsion bar portion 66 and the central portion, thereby the vehicle body 14 and the left and right wheels 12. A force in the direction in which they approach and separate from each other is applied via the torsion spring 64. Therefore, according to the present suspension device 10, as described above, the posture of the vehicle body is controlled by suppressing the roll amount and pitch amount of the vehicle body, or so-called skyhook control is executed, so A vehicle with excellent maneuverability and stability will be realized.

<Modification>
FIG. 7 shows an enlarged central portion of a torsion bar included in a suspension device according to a modification. The torsion bar in the modified example is also formed by connecting three members in the same manner as in the above embodiment, and the intermediate torsion bar member is different from the intermediate torsion bar member 62 in the above embodiment. The intermediate torsion bar member 250 in the present modification includes a pair of main bars 252, a pair of inner cylinders 254 that are externally fitted to each of them, and an outer cylinder 256 that is externally fitted to the pair of inner cylinders 254. It is the same as the intermediate torsion bar member 62 in the above embodiment. However, the intermediate torsion bar member 250 in the present modification is shaped so that each of the pair of inner cylinders 254 is folded inside the outer cylinder 256 as shown in the figure, and the inner side of the main bar 252 And the end of the outer cylinder 256 are connected to each other. In other words, the torsion bar of the present modified example has an effect of increasing the length as compared with the above-described embodiment, and the rigidity against torsion of the torsion bar is sufficiently ensured.

  10: Vehicle suspension device 12: Wheel 14: Vehicle body 36: Second lower arm (lower spring) 50: Torsion bar spring device (suspension spring) 52: Hydraulic shock absorber 56: Mount portion (upper spring) 60: 1 pair L-shaped bar member (first torsion bar member, second torsion bar member) 62: intermediate torsion bar member (third torsion bar member) 64: torsion spring 66: torsion bar portion 68: one pair of arm portions 70: anchor arm (Fixing device) 100: Actuator 110: Housing 112: Electromagnetic motor 114: Differential device 200: Suspension electronic control unit (actuator force control device)

Claims (5)

A torsion bar disposed on the vehicle body along an axis extending in the vehicle width direction;
A pair of arms extending from each of both ends of the torsion bar so as to cross the torsion bar and connected to the left and right wheel holding members at the tip,
A fixing device that fixes a central portion of the torsion bar in the axial direction to the vehicle body and prohibits rotation of the central portion of the torsion bar;
Each is (a) a housing fixed to the vehicle body and rotatably held in a state of passing through the torsion bar, and (b) housed in the housing and rotated to the torsion bar depending on the force generated by itself. An electromagnetic motor for applying a force, and a pair of actuators for applying a rotational force to each of the portions between each of both end portions and the central portion of the torsion bar,
The portion of the torsion bar between the center portion and one of both end portions and the portion between the center portion and the other of the both end portions are configured to be twisted, respectively, The vehicle body is suspended by force, and the rotational force applied to the torsion bar by the pair of actuators applies a force in a direction in which the left and right wheels and the vehicle body approach and separate from each other. A vehicle suspension device configured as described above. The torsion bar
A pair of main bar portions that are coaxial with each other and are disposed in a state in which one end portions thereof are close to each other, and each of the other end portions is provided with the pair of arms,
Each of the pair of main bar portions is externally fitted to the one corresponding to itself, and one end portion of the pair is connected to one end portion of the pair of main bar portions corresponding to itself. A pair of inner cylinders;
2. The vehicle according to claim 1, wherein the vehicle has an outer cylinder portion that is fitted onto the pair of inner cylinder portions, and each of its both end portions is connected to the other end portion of each of the pair of inner cylinder portions. Suspension device. Each of the pair of actuators applies a rotational force in each of the pair of main bar portions,
The vehicle suspension device according to claim 2, wherein the fixing member fixes a part of the outer cylinder portion to the vehicle body. The torsion bar
A first torsion bar member provided at one end with one of the pair of arms;
A second torsion bar member provided at one end with the other of the pair of arms;
Both end portions are detachably connected to the other end portion of the first torsion bar member and the other end portion of the second torsion bar member to connect the first torsion bar member and the second torsion bar member. The vehicle suspension device according to any one of claims 1 to 3, comprising a third torsion bar member to be connected. Each of the pair of actuators applies a rotational force in each of the first torsion bar member and the second torsion bar member,
The vehicle suspension device according to claim 4, wherein the fixing member fixes a part of the third torsion bar member to a vehicle body.

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