JP2008189007A - Suspension device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a suspension device capable of further saving a space for a steer-by-wire system and making an operation for assembling the steer-by-wire system to a vehicle body efficient. <P>SOLUTION: A steering shaft 12 is rotated around an axial line by an actuator, and a flange part 16 and a hub 17 are rotated relative to a suspension assembly 23 around the axial line of the steering shaft 12 to steer a wheel 19. Thereby, there is no need of a steering rod, and a steering device can be housed inside the wheel 19 so as to save a space for a steer-by-wire system. Also, the steering device including the actuator can be integrally incorporated in the suspension device 1, so as to make an operation for assembling the system to a vehicle body 5 efficient. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a vehicle suspension device, and more particularly, to a vehicle suspension device employing a steer-by-wire system.

In recent years, vehicles employing a steer-by-wire system have attracted attention (for example, see Patent Document 1). In the steer-by-wire system, the mechanical connection between the steering shaft connected to the steering wheel and the steering device that steers the wheel is disconnected. There is an advantage that the running stability performance of the vehicle can be improved by controlling each wheel individually.
JP 2004-359210 A

  However, in the steer-by-wire system, it is difficult to dispose the steering device, particularly the actuator, in the vicinity of the wheel due to installation space limitations. Therefore, in the conventional steer-by-wire system, the actuator is disposed at a position relatively away from the wheel, and the steering shaft is connected to the knuckle via the link (tie rod). Thereby, depending on the arrangement of the actuator, the space at the foot of the corner of the corner may be sacrificed, and there has been a demand for downsizing of the steering device. Further, since the steer-by-wire system has a structure in which the steering device and the suspension device are independent, the assembly to the vehicle body becomes complicated, and the efficiency of the assembly work has been demanded.

  Therefore, the present invention has been made in view of the above circumstances, and an object of the present invention is to provide a suspension device in which the steer-by-wire system is further reduced in space and the work of assembling the steer-by-wire system to the vehicle is made efficient. To do.

  In order to achieve the above object, the invention according to claim 1 of the present invention is a vehicle suspension device adopting a steer-by-wire system, and is provided between a vehicle body and a wheel to move the wheel up and down. And a steering device for steering the wheel, the steering device including the wheel side member and the wheel. And a steering unit that supports the wheel so as to be steerable, and an actuator that steers the wheel by rotating the steering unit around a steering shaft. .

  According to a second aspect of the present invention, in the suspension device according to the first aspect, the steering unit is provided with a steering shaft on one of the wheel side member or the wheel and the steering unit on the other of the wheel side member or the wheel. A support member that rotatably supports the shaft is provided, and the steering device is configured to steer the wheel by rotating the steering shaft with respect to the support member by an actuator.

  According to a third aspect of the present invention, in the suspension device according to the second aspect, the steering shaft is provided coaxially with respect to the wheel side member.

  According to a fourth aspect of the present invention, in the suspension device according to the first aspect, the steering device includes a link member having one end connected to the steering portion, and is linked by an actuator provided on the wheel side member. The wheel is steered by moving the member linearly.

Therefore, in the invention relating to the suspension device according to the first aspect, the wheel can be steered by rotating the steered portion around the steered shaft by the actuator of the steerer.
In the invention relating to the suspension device according to the second aspect, the wheel can be steered by rotating the steering shaft of the steering portion with respect to the support member by the actuator.
In the invention relating to the suspension device according to claim 3, the wheel can be steered by rotating the steering shaft provided coaxially with respect to the wheel side member with respect to the support member by the actuator. .
In the invention according to the suspension device of the fourth aspect, the wheel can be steered by moving the link member linearly by the actuator.

  According to the invention relating to the suspension device according to any one of claims 1 to 4, the wheel is moved by rotating the steering portion provided between the wheel-side member and the wheel about the steering shaft by the actuator. Steered. Thereby, space saving of a steer-by-wire system is possible, and the assembly | attachment work to a vehicle body can be made efficient.

(First embodiment)
A suspension device 1 according to a first embodiment will be described with reference to FIGS. 1 and 2. The suspension device 1 of the first embodiment is a vehicle suspension device 1 in which a steer-by-wire system is constructed, and includes a cylinder device 2 including a vehicle body side member and a wheel side member, a wheel side member, and a wheel 19. It is comprised by the steering apparatus 3 arrange | positioned between. The vehicle body side member includes a rod 6 having a base end portion fixed to the vehicle body 5 via the upper mount 4 and a piston fixed to the distal end portion. The wheel side member includes a cylinder 8 in which a piston is slidably contacted with an inner peripheral surface and a bracket 7 is provided on the outer peripheral surface. The bracket 7 is connected to the upper part inside the knuckle 9 (left side in FIG. 1), and the lower arm 10 is connected to the inner lower part of the knuckle 9 via a connecting pin 11. The suspension device 1 includes a suspension assembly 23 including a cylinder device 2, a suspension member 22 (spring), and an upper mount 4.

  As shown in FIG. 2, the steering device 3 includes a steering unit that is provided between the wheel-side member and the wheel 19 and supports the wheel 19 so as to be steerable, and the steering unit is connected to the steering shaft 12. And a torque motor 13 (actuator) that steers the wheel 19 by turning it around. The steering portion includes a housing 14 connected to the knuckle 9, a steering shaft 12 whose both ends are rotatably supported by a pair of guide members 15 (support members) disposed in the housing 14, and the steering shaft. The flange portion 16 is provided at an intermediate portion of the opposite shaft 12 and connected to the wheel via the hub 17. The torque motor 13 is provided in the housing 14 so as to be accommodated in the space inside the wheel 19 b, and the output shaft is connected to the steering shaft 12 via the speed reducer 18. As a result, the suspension device 1 causes the wheel 19 to be operated by rotating the steering shaft 12 around the axis line via the speed reducer 18 by the torque motor 13 and rotating the flange portion 16 around the steering shaft 12. It has a structure that is oriented. Note that suspension parts including wheels 19 (tires 19 a and wheels 19 b) and a brake disk 20 are fixed to the flange portion 16 via the hub 17.

  Next, the operation of the suspension device 1 of the first embodiment will be described. When the steering wheel is steered by the driver, the steering angle, the steering speed, and the steering torque are detected by the detection device, and the steering control device including the microcomputer detects the torque motor 13 based on the detection result of the detection device. (Actuator) is activated. The rotational force of the torque motor 13 is transmitted to the steering shaft 12 of the steering section via the speed reducer 18, and the steering shaft 12 is rotationally driven around the axis. As a result, the flange portion 16 and the hub 17 are rotated in the predetermined direction around the steering shaft 12 with respect to the suspension assembly 23, and the wheel 19 is steered. When the wheel 19 moves up and down due to road surface unevenness or the like, the cylinder 8 (wheel side member) and the rod 6 (vehicle body side member) of the cylinder device 2 are relatively moved (displaced) in the axial direction of the cylinder device 2. A damping force is generated by opening and closing a valve provided on the piston.

The first embodiment has the following effects.
According to the suspension device 1, the steering shaft 12 of the steering portion is rotated around the axis by the torque motor 13 (actuator) of the steering device, so that the flange portion 16 and the hub 17 are operated with respect to the suspension assembly 23. The wheel 19 is steered by rotating around the axis of the direction axis 12. As a result, the suspension device 1 can steer the front, rear, left, and right wheels 19 of the vehicle independently according to the operation of the driver, and the driving stability can be improved by finely controlling the behavior of the vehicle. Can be improved.
For example, steering control according to the traveling speed of the vehicle can be performed, and in a high speed region, the steering stability performance of the vehicle is improved by reducing the steering amount of the wheel 19 with respect to the steering wheel operation amount. Is possible. Further, in the low speed region, by increasing the steering amount of the wheel 19 with respect to the operation amount of the steering wheel, it becomes possible to easily enter a garage in a narrow place and reduce the burden on the driver. it can.
In addition, according to the suspension device 1, the toe of each wheel 19 can be adjusted by steering the wheel 19 by each torque motor 13, and the alignment can be easily adjusted.
Further, according to the suspension device 1, since the torque motor 13 (actuator) and the speed reducer 18 are accommodated in the space inside the wheel 19b, a steering rod that has been conventionally disposed under the floor of the vehicle becomes unnecessary. Comfort can be improved by expanding the foot space of the passenger compartment. Further, the steering device including the torque motor 13 can be integrated into the suspension device 1 so that the steer-by-wire system, and thus the suspension device 1 can be saved, and the vehicle body 5 of the steer-by-wire system can be saved. Assembling work can be made more efficient.
In the first embodiment, the case of the strut suspension has been described. However, the first embodiment can be applied to a suspension using a shock absorber.

(Second Embodiment)
A suspension device 21 according to the second embodiment will be described with reference to FIG. In addition, the same name and code | symbol are provided to the structure which is the same as that of the suspension apparatus 1 of 1st Embodiment, or it corresponds, and the detailed description is abbreviate | omitted. The steering device 3 is provided at the lower end portion of the cylinder 8 (wheel side member) and is disposed on the same axis L0 with respect to the cylinder device 2, and an output shaft of the torque motor 13. And a steering shaft 12 connected via a speed reducer 18. The steering shaft 12 is rotatably supported around the axis L0 by a bearing housed in a casing 24 (support member) formed integrally with the torque motor 13 and the speed reducer 18. Further, the steering shaft 12 is provided with a pair of brackets 25 that are arranged to face each other with a predetermined interval, and the brackets 25 are connected to the wheels via a hub. A bracket 26 is provided on the outer peripheral surface of the cylinder 8, and the bracket 26 is connected to the lower arm via a connecting pin, so that the cylinder 8 (wheel side member) has an axis line with respect to the rod 6 (vehicle body side member). Relative movement (rotation) around L0 is prevented.

  Next, the operation of the suspension device 21 of the second embodiment will be described. When the steering wheel is steered by the driver, the steering angle, the steering speed, and the steering torque are detected by the detection device, and the steering control device including the microcomputer detects the torque motor 13 based on the detection result of the detection device. (Actuator) is activated. The torque of the torque motor 13 is transmitted to the steering shaft 12 via the speed reducer 18, and the steering shaft 12 is rotationally driven around the axis. As a result, the hub rotates in a predetermined direction around the steering shaft 12 with respect to the cylinder device 2 via the bracket 25, and the wheels are steered. When the wheel moves up and down due to road surface unevenness or the like, the cylinder 8 (wheel side member) and the rod 6 (vehicle body side member) of the cylinder device 2 are relatively moved (displaced) in the axial direction of the cylinder device 2. A damping force is generated by opening and closing a valve provided on the piston 27.

  According to the suspension device 21 of the second embodiment, an effect equivalent to that of the suspension device 1 of the first embodiment can be obtained. In addition, according to the suspension apparatus 21 of 2nd Embodiment, a knuckle can be omitted compared with the suspension apparatus 1 of 1st Embodiment, and further simplification and weight reduction are attained.

(Third embodiment)
A suspension device 31 according to a third embodiment will be described with reference to FIG. In addition, the same name and code | symbol are attached | subjected to the structure which is the same as that of the suspension apparatuses 1 and 21 of 1st and 2nd Embodiment, or equivalent, and the detailed description is abbreviate | omitted. The steering device 3 includes a steering member 32 in which a base portion 32a is provided at the lower end portion of the cylinder 8 (wheel side member) so as to be rotatable around the axis L0, and the wheel 19 is connected to the distal end portion via a hub 17. A first link member 33 in which the base portion 33a is provided on the cylinder 8 so as to be rotatable around the axis L0; and a first portion 34a provided on the cylinder 8 so as to be rotatable around the axis L0 and extending from the base portion 34a. The distal end portion 35a of the arm 35 is rotatably connected to the distal end portion 33b of the first link member 33, and the distal end portion 36a of the second arm 36 extending from the base portion 34a is connected to the base portion 32a of the steering member 32. And a torque motor 13 (actuator) provided coaxially with the cylinder 8 and having an output shaft connected to the base 34a of the first link member 34. Composed of Te.

Next, the operation of the suspension device 31 of the third embodiment will be described. When the steering wheel is steered by the driver, the steering angle, the steering speed, and the steering torque are detected by the detection device, and the steering control device including the microcomputer detects the torque motor 13 based on the detection result of the detection device. (Actuator) is activated. The rotational force of the torque motor 13 is transmitted to the first link member 33, and the first link member 33 is rotationally driven around the axis L0. Thereby, the steering member 32 rotates around the axis L0 via the second link member 34, and the wheel 19 is steered. When the wheel 19 moves up and down due to road surface unevenness or the like, the cylinder 8 (wheel side member) and the rod (vehicle body side member) of the cylinder device 2 are relatively moved (displaced) in the axial direction and provided on the piston. A damping force is generated by opening and closing the valve.
According to the suspension device 31 of the third embodiment, an effect equivalent to that of the suspension device 1 of the first embodiment can be obtained.

(Fourth embodiment)
A suspension device 41 according to a fourth embodiment will be described with reference to FIGS. In addition, the same name and code | symbol are provided to the structure which is the same as that of the suspension apparatus 1,21,31 of 1st-3rd Embodiment, or 31, and the detailed description is abbreviate | omitted. The vehicle body side member 42 is formed of a hollow shaft having a polygonal cross section (octagonal in the fourth embodiment) (the cross section of the hollow portion is circular), and one end thereof is fixed to the vehicle body 5 via the upper mount 4. The vehicle body side member 42 is inserted into the cylinder 43 (wheel side member) so as to be relatively displaceable in the axial direction (vertical direction in FIG. 6), and constitutes a cylinder device together with the cylinder 43. Since the vehicle body side member 42 and the cylinder 43 (wheel side member) have a polygonal cross section, relative movement (rotation) around the axis L0 between the vehicle body side member 42 and the cylinder 43 is prevented. A cylinder chamber 44 is formed in the hollow portion of the vehicle body side member 42, and a piston 46 attached to an upper end portion of a rod 45 whose lower end portion is fixed to the bottom portion of the cylinder 43 is provided in the cylinder chamber 44. Be contained.

At the lower part of the cylinder 43 (wheel side member), a steering portion, that is, a bracket 7 having a gear 47 fixed to the upper end portion thereof is provided to be rotatable around an axis L0 through a bearing. A torque motor 13 (actuator) in which a pinion gear 48 fixed to the output shaft is engaged with the gear 47 is provided on the outer peripheral surface of the cylinder 43. The lower arm 10 is rotatably connected to the hub 17 via a connecting member 49 formed of a ball joint.
* In the lower part of Fig. 5, the reference number of the part connected to the lower arm 10 (connecting member) is incorrect. It is “19”, but “49” is correct.

Next, the operation of the suspension device 41 of the fourth embodiment will be described. When the steering wheel is steered by the driver, the steering angle, the steering speed, and the steering torque are detected by the detection device, and the steering control device including the microcomputer detects the torque motor 13 based on the detection result of the detection device. (Actuator) is activated. The torque of the torque motor 13 is transmitted to the bracket 7 via the pinion gear 48 and the gear 47, and the bracket 7 is rotationally driven around the axis L0. Thereby, the hub 17 rotates in the predetermined direction around the axis L0 with respect to the cylinder 43 (wheel side member), and the wheel 19 is steered. When the wheel 19 moves up and down due to road surface unevenness or the like, the vehicle body side member 42 and the cylinder 43 (wheel side member) are relatively moved (displaced) in the axial direction to open and close the valve provided on the piston 46. To generate a damping force.
According to the suspension device 41 of the fourth embodiment, an effect equivalent to that of the suspension device 1 of the first embodiment can be obtained.

(Fifth embodiment)
A suspension device 51 according to a fifth embodiment will be described with reference to FIG. In addition, the same name and code | symbol are provided to the structure which is the same as that of suspension apparatus 1,21,31,41 of 1st-4th Embodiment, or equivalent, and the detailed description is abbreviate | omitted. The rod 6 (vehicle body side member) is fixed to the vehicle body 5 via the upper mount 4. The cylinder 8 (wheel side member) is connected to an intermediate portion of the lower arm 10 through a lower bracket 52 having a U-shaped cross section. The lower arm 10 has an end on the inner side of the vehicle body 5 (right side in FIG. 7) connected to the vehicle body 5 and an end on the outer side of the vehicle body 5 (left side in FIG. 7) rotates to the lower end portion of the hub 17 via the ball joint 53. Connected as possible. A bracket arm 54 is fixed to the cylinder 8, and a tip end portion of the bracket arm 54 is rotatably connected to an upper end portion of the hub 17 via a ball joint 55.

  A torque motor 13 (actuator) is provided inside the vehicle body 5 of the cylinder 8 (vehicle body side member). The output shaft of the torque motor 13 is connected to the link member 56 via the speed reducer 18. A gear for converting the rotational motion of the torque motor 13 into a linear motion in the horizontal direction of the link member 56 is incorporated in the input shaft and the output shaft of the speed reducer 18. The end of the link member 56 outside the vehicle body 5 is rotatably connected to the hub 17 via a ball joint. Here, the hub 17, the ball joints 53 and 55, and the link member 56 constitute a steering portion.

Next, the operation of the suspension device 51 of the fifth embodiment will be described. When the steering wheel is steered by the driver, the steering angle, the steering speed, and the steering torque are detected by the detection device, and the steering control device including the microcomputer detects the torque motor 13 based on the detection result of the detection device. (Actuator) is activated. The torque of the torque motor 13 is converted into a force that causes the link member 56 to move linearly by the speed reducer 18, and the link member 56 is driven in the vehicle body 5 in and out of the vehicle body 5 (left and right direction in FIG. 7). As a result, the hub 17 rotates in a predetermined direction around the steering axis (the axis connecting the ball joint 53 and the ball joint 55) with respect to the cylinder device 2, and the wheel 19 is steered. When the wheel 19 moves up and down due to road surface unevenness or the like, the cylinder 8 (wheel side member) and the rod 6 (vehicle body side member) of the cylinder device 2 are moved relative to each other in the axial direction (displaced) to form a piston. A damping force is generated by opening and closing the provided valve.
According to the suspension device 51 of the fifth embodiment, an effect equivalent to that of the suspension device 1 of the first embodiment can be obtained.

(Sixth embodiment)
A suspension device 61 according to a sixth embodiment will be described with reference to FIGS. In addition, the same name and code | symbol are provided to the structure which is the same as that of suspension apparatus 1,21,31,41,51 of 1st-5th Embodiment, or equivalent, and the detailed description is abbreviate | omitted. The rod 6 (vehicle body side member) is fixed to the vehicle body 5 via the upper mount 4. A bracket 7 is provided on the outer peripheral surface of the cylinder 8 (wheel side member), and the bracket 7 is rotatably connected to the hub 17 via a ball joint 62. An actuator 63 is provided at the lower end of the cylinder 8. The actuator 63 is formed on the outer peripheral surface of the torque motor 13 accommodated in the casing 64, a nut 66 connected to the output shaft of the torque motor 13 and rotatably supported by the casing 64 via a bearing 65. The threaded portion is screwed into a groove threaded on the inner peripheral surface of the nut 66, and the tip portion is constituted by a link member 67 that is rotatably connected to the hub 17 via a ball joint 68. An end of the lower arm 10 on the outer side of the vehicle body 5 is rotatably connected to the lower end portion of the hub 17 via a ball joint 69, and the hub 17 and the ball joints 62 and 69 constitute a steering portion.

Next, the operation of the suspension device 61 of the sixth embodiment will be described. When the steering wheel is steered by the driver, the steering angle, the steering speed, and the steering torque are detected by the detection device, and the steering control device including the microcomputer detects the torque motor 13 based on the detection result of the detection device. Is activated. By driving the torque motor 13, the nut 66 of the actuator 63 rotates, and the link member 67 screwed to the nut 66 is driven in the axial direction. As a result, the hub 17 rotates in a predetermined direction around the steering axis (the axis connecting the ball joint 62 and the ball joint 69) with respect to the cylinder device 2, and the wheel 19 is steered. When the wheel 19 moves up and down due to road surface unevenness or the like, the cylinder 8 (wheel side member) and the rod 6 (vehicle body side member) of the cylinder device 2 are moved relative to each other in the axial direction (displaced) to form a piston. A damping force is generated by opening and closing the provided valve.
According to the suspension device 61 of the sixth embodiment, an effect equivalent to that of the suspension device 1 of the first embodiment can be obtained.

1 is an overall view of a suspension device according to a first embodiment. It is explanatory drawing of the suspension apparatus of 1st Embodiment, Comprising: It is a figure which shows the structure of a steering apparatus especially. It is explanatory drawing of the suspension apparatus of 2nd Embodiment, Comprising: It is the figure which showed the cylinder apparatus with the axial cross section especially. It is a perspective view of the suspension apparatus of 3rd Embodiment. It is a general view of the suspension apparatus of 4th Embodiment. It is explanatory drawing of the suspension apparatus of 4th Embodiment, Comprising: It is the figure which showed the vehicle body side member and the wheel side member in the cross section especially. It is a general view of the suspension apparatus of 5th Embodiment. It is a general view of the suspension apparatus of 6th Embodiment. It is explanatory drawing of the suspension apparatus of 6th Embodiment, Comprising: It is a top view of the steering apparatus which showed the actuator in cross section especially.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Suspension apparatus, 2 cylinder apparatus, 3 steering apparatus, 5 vehicle body, 6 rod (vehicle body side member), 8 cylinder (wheel side member), 12 steering shaft, 13 torque motor (actuator), 14 housing (steering part) ), 15 guide member (steering part), 16 flange part (steering part), 19 wheels

Claims (4)

A vehicle suspension device employing a steer-by-wire system,
A cylinder device composed of a vehicle body side member and a wheel side member provided between the vehicle body and the wheel and relatively displaced in the axial direction according to the vertical movement of the wheel; and a steering device for steering the wheel; Comprising
The steering device is
A steering unit provided between the wheel side member and the wheel to support the steering of the wheel;
An actuator for rotating the steering unit around a steering axis to steer the wheel;
A suspension device comprising: The steering unit is provided with the steering shaft on one of the wheel side member or the wheel and a support member that rotatably supports the steering shaft on the other of the wheel side member or the wheel,
The suspension device according to claim 1, wherein the steering device steers a wheel by rotating the steering shaft with respect to the support member by the actuator. The suspension device according to claim 2, wherein the steering shaft is provided coaxially with respect to the wheel side member. The steering device includes a link member having one end connected to the steering unit, and the wheel is steered by linearly moving the link member by an actuator provided on the wheel side member. The suspension device according to claim 1.

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