JPH05178042A - Suspension with variable arm length device - Google Patents

Abstract

PURPOSE:To provide a suspension with a variable arm length device used preferably for a vehicle such as automobile, etc., required strictly for steering and vibration preventing characteristics, which can control the suspension arm length to ensure the sufficient control width while being miniaturized without changing rigidity of the suspension. CONSTITUTION:A variable arm length device 3 built in a suspension arm interconnecting the car body side and wheel side and capable of changing the interconnecting length between the car body side and wheel side is provided in a suspension provided on a vehicle to be composed of an arm expanding and contracting mechanism 4 for expanding and contracting the suspension arm in the direction of the arm length, a rotary drive mechanism 5 equipped with the mechanism 4 as an operative source and a conversion mechanism for converting the pivoting by the mechanism 5 to the expanding and contracting operation of the mechanism 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a suspension for a vehicle, and more particularly to a suspension with a variable arm length device, which is suitable for use in a vehicle such as an automobile in which steering characteristics and anti-vibration characteristics are strictly required.

[0002]

2. Description of the Related Art Vehicles such as automobiles have been developed in which the rigidity of a suspension can be adjusted according to the taste of a driver or the like. As a mechanism for adjusting the rigidity of such a suspension, a mechanism that adjusts the roll rigidity by changing the mounting point of the stabilizer or a mechanism that adjusts the rigidity of the suspension bush that elastically attaches the suspension to the vehicle body is used. There are types.

On the other hand, in order to control the suspension alignment to a desired state, it may be possible to control the length of the suspension arm to a desired state. At the time of such control, it is conceivable to use the suspension bush provided for changing the rigidity and provide an oil chamber in the suspension bush.

[0004]

However, the means for providing the oil chamber as described above has a problem that when the suspension arm is expanded or contracted, the bush rigidity is largely changed and the vibration damping function is deteriorated. Therefore, it is desired to equip a device that can control the length of the suspension arm without changing the rigidity of the suspension bush.

Further, it is desirable that the above-mentioned device is a small device which can be installed in a suspension of a vehicle, but has a sufficient control width. The present invention has been devised in view of such a problem, and makes it possible to control the length of the suspension arm without changing the suspension rigidity, and a small device that can be installed in the vehicle suspension is sufficient. It is an object of the present invention to provide a suspension with a variable arm length device, which has a wide control range.

[0006]

Therefore, the suspension with a variable arm length device of the present invention is a suspension provided for a vehicle, and a suspension arm for connecting a vehicle body side and a wheel side, and an interior of the suspension arm. And an arm length changing device that can change the connection length between the vehicle body side and the wheel side. The arm length changing device extends and contracts the suspension arm in the arm length direction, and the arm extending and retracting mechanism. It is characterized by comprising a rotary drive mechanism equipped as an operation source and a conversion mechanism for converting rotation by the rotary drive mechanism into expansion / contraction operation of the arm expansion / contraction mechanism.

[0007]

In the suspension with the variable arm length device of the present invention described above, in the variable arm length device, when the rotary drive mechanism equipped as the operation source of the arm extension mechanism operates, the rotation of the rotary drive mechanism is changed by the conversion mechanism. The suspension arm is expanded and contracted in the arm length direction by the arm expansion and contraction mechanism, and the connection length between the vehicle body side and the wheel side is changed to a desired state.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A suspension with an arm length varying device according to an embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a longitudinal sectional view of an essential part schematically showing the arm length varying device, and FIG. 1 is a sectional view taken along the line CC of FIG. 1, FIG. 3 is a sectional view taken along the line AA of FIG. 1, FIG. 4 is a sectional view taken along the line BB of FIG. 1, and FIG. 6A is a schematic perspective view, FIG. 6A is a schematic perspective view showing a detection means for detecting the rotation state of the rotation drive mechanism, and FIG.
FIG. 7 is a schematic diagram showing the waveform of the output signal of the detection means in (a), and FIG. 7 is a schematic sectional view showing a modified example of the rotary drive mechanism.

Suspension 1 with variable arm length device
As shown in FIG. 5, the suspension arm 2 is interposed between the vehicle body side A and the wheel side B of the automobile, and the wheel side B is suspended on the vehicle body side A in a required state. And
The suspension arm 2 is elastically supported at its mounting portion on the vehicle body side A via a rubber body.

Further, the suspension arm 2 is provided with an arm length changing device 3 at an intermediate portion in the arm direction, and the connection length between the vehicle body side A and the wheel side B can be changed by its operation. ing. Arm length changing device 3
Is configured as shown in FIG. 1, and includes an arm extension / contraction mechanism 4,
The rotary drive mechanism 5 and the conversion mechanism 6 are provided.

That is, the arm extension / contraction mechanism 4 has an output shaft 7 whose tip is connected to the wheel side B, and a casing 9 in which the output shaft 7 is loosely inserted through a tip opening 9A. The end side is connected to the vehicle body side A, and the length of the suspension arm 2 is changed by the extension / contraction of the arm extension / contraction mechanism 4, and the connection length between the vehicle body side A and the wheel side B is changed.

A rotary drive mechanism 5 is internally provided on the base end side of the casing 9. That is, as shown in FIGS. 1 and 2, the rotary drive mechanism 5 includes a drive shaft 10 and a vane 1.
1, a rectangular plate-shaped vane 11 has its inner end fixed to the drive shaft 10, and its outer end slidable on the inner circumference of a cylinder (oil chamber) 9B formed on the inner circumference of the base end of the casing 9. The vanes 11 are in contact with each other, and the vane 11 is rotationally driven around the axis in the cylinder 9B by supplying / discharging the working oil into / from the cylinder 9B through the supply / drain holes 9C and 9D. In addition,
Reference numeral 9F is a partition wall that divides the inside of the cylinder 9B into two oil chambers.

The drive shaft 10 is also driven by the vanes 11. The drive shaft 10 is pivotally supported by the casing 9 via bearings 12 and 13, and the drive shaft 10 is supplied and discharged with a required amount of hydraulic oil in the cylinder 9B. 10 is rotated by a required amount. The rotary drive mechanism 5 includes the drive shaft 1
It has a planetary gear mechanism S connected to zero.

That is, the carrier 14 of the planetary gear mechanism S
Is fixed to the tip of the drive shaft 10, and the rotation of the drive shaft 10 is transmitted to the planetary gear 15 via the carrier 14. A ring gear 17 is formed on the inner circumference of the casing 9, and the planetary gear 15
Are screwed together.

By the way, a sun gear 16 disposed between the planetary gears 15 and screwed together with the planetary gears 15.
Is fixed to a rotary shaft 8 provided on the tip side of the casing 9, and the rotary shaft 8 constitutes a conversion mechanism 6 for converting the rotation of the rotary drive mechanism 5 into the expansion / contraction motion of the arm expansion / contraction mechanism 4. There is. That is, the rotary shaft 8 is pivotally supported on the inner circumference of the casing 9 via bearings 18 and 19, and the sun gear 1
It is designed to rotate with the rotation of 6.

Further, the rotary shaft 8 is formed in a sheath shaft shape and has a hole 8A at the front end side, and the rear end portion of the output shaft 7 is fitted in the hole 8A. The rear end side of the output shaft 7 and the hole 8A of the rotary shaft 8 are screwed to each other via the threaded portions formed in each of them. By the way, the output shaft 7 is formed with a groove 7A extending in the axial direction thereof, and a rotation prevention guide 9E projectingly provided at the tip of the casing 9 is locked in the groove 7A so that the output shaft 7 is prevented. Is prevented from rotating, and the output shaft 7 is allowed to be driven only in the axial direction.

Therefore, the output shaft 7 is always in the non-rotating state, and the rotation of the rotating shaft 8 is converted into the axial drive of the output shaft 7 by the screw portion, so that the arm length varying device 3 is expanded and contracted. ing. In addition, the rotary drive mechanism 5 described above.
May be constituted by a hydraulic vane type actuator, an electric servo motor, a stepping motor, an ultrasonic motor, or the like.

The rotating shaft 8 is provided with a detecting means 20 for detecting the rotating state of the rotary drive mechanism. That is, as shown in FIG. 6A, the detection means 20 is composed of a pulse encoder and a generator that generate a pulse corresponding to the rotation, and by the pulse generation by the transmission through the hole 8B of the rotation shaft 8, A pulse signal as shown in (b) is output, and the amount of rotation of the rotary shaft 8 is detected by counting this pulse.

Then, by feedback-controlling the output of the detecting means 20, the arm length varying device 3 is controlled to a required state and a required arm length is obtained. Since the suspension with the arm length varying device as one embodiment of the present invention is configured as described above, it is necessary that the controller controls the arm length varying device 3 to change the arm length based on information from various sensors. , A control signal is output.

As a result, in the arm length varying device 3, the cylinder 9B of the rotary drive mechanism 5 is provided with the supply / discharge holes 9C, 9D.
Through, the required amount of hydraulic oil is supplied and discharged. The vane 11 is rotated in the cylinder 9B, and along with this, the drive shaft 1
0 and the carrier 14 are rotated so that the planetary gear 1
5 rotates and revolves while meshing with the ring gear 17.

Due to the revolution of the planetary gear 15, the sun gear 16 rotates and the rotary shaft 8 of the conversion mechanism 6 rotates a required amount. In the conversion mechanism 6, the rotation of the rotary shaft 8 is
The threaded portion of the hole 8A and the threaded portion of the output shaft 7 are screwed together to be converted into an axial displacement of the output shaft 7. As a result, the output shaft 7 expands and contracts with respect to the casing 9 of the arm expansion / contraction mechanism 4, and the required arm length in the arm length changing device 3 is realized.

In this way, the suspension arm 2
The expansion / contraction control of the suspension arm 2 is performed without causing a change in the rigidity of the elastic connecting portion of the suspension arm 2 to the vehicle body side A, and roll steer, roll camber control, etc. can be easily performed without reducing the vibration damping function. Become. Further, since the extension / contraction control of the suspension arm 2 is performed by converting the rotation of the rotary drive mechanism 5 by hydraulic pressure into the extension / contraction operation by the conversion mechanism 6, the device width in the arm length direction is reduced, and the arm length variable device 3 is set. Since it can be configured compactly, the expansion and contraction width can be widened.

Further, when a simple cylinder type is adopted as the arm length varying device 3, it is necessary to hold the position with a spring or the like in consideration of a failure, but such a spring is larger as the external force is larger. Becomes
It causes layout problems. Further, the operation of the variable arm length device 3 needs to be performed by pushing the fail-safe spring away, and in addition to requiring a large amount of power for the operation, it is necessary to secure the expansion and contraction width of the spring, which is a large device. Become.

In response to such a situation, in the structure of this embodiment, the arm length varying device 3 includes the rotary drive mechanism 5 and the converting mechanism 6.
Since and are used, the above-mentioned problems do not occur and a compact device is realized. Also, the output shaft 7 and the rotary shaft 8
Since the drive direction converting mechanism 6 between and is of a screw type, the frictional force at the time of screwing the screw part becomes resistance,
It is advantageous in fail-safe.

Further, in this embodiment, since the planetary gear mechanism is used for the rotary drive mechanism 5, the reduction ratio can be set large and the arm length can be changed with a small control power. Thereby, the arm length varying device 3 can be made compact. Instead of the rotary drive mechanism 5 of the present embodiment, a rotary drive mechanism 21 as shown in FIG. 7 can be considered. This rotary drive mechanism 21 is provided with an eccentric rotor 21A having a plurality of vanes 21B radially in a cylinder 9B of a casing 9. The eccentric rotor 21A can rotate at its eccentric position (the position shown in FIG. 7), and each vane 21B has its base end loosely fitted in the rotor 21A and is pressed outward by the spring 21C. ing.

As a result, for example, when oil is supplied from the supply / discharge hole 9C and discharged from the supply / discharge hole 9D, the vane 21B indicated by the symbol a receives pressure from the supply / discharge hole 9C side and the rotor 21.
A is driven to rotate counterclockwise in the figure. Thus, vane 2
While expanding and contracting 1B, vane 21B and rotor 21A
Rotates.

[0027]

As described above in detail, according to the suspension with a variable arm length device of the present invention, in a suspension provided for a vehicle, a suspension arm connecting the vehicle body side and the wheel side, and the suspension arm An arm length changing device that is internally installed and that can change the connection length between the vehicle body side and the wheel side is provided. The arm length changing device extends and contracts the suspension arm in the arm length direction, and the arm extension and contraction mechanism. With a simple configuration including a rotary drive mechanism equipped as an operation source of the mechanism and a conversion mechanism for converting rotation by the rotary drive mechanism into expansion / contraction operation of the arm expansion / contraction mechanism, An effect or an advantage is obtained. (1) The extension and contraction control of the suspension arm is performed without causing a change in the rigidity of the elastic connection portion of the suspension arm to the vehicle body side, and roll steer, roll camber control, etc. can be easily performed without lowering the vibration damping function. Become so. (2) Since the extension / contraction control of the suspension arm is performed by converting the rotation of the rotation drive mechanism into the extension / contraction operation by the conversion mechanism, the device width in the arm length direction is reduced, and the arm length variable device is configured compactly. As a result, the expansion and contraction width can be increased. (3) When a simple cylinder type is adopted as the arm length varying device, it is necessary to hold the position with a spring or the like in consideration of a failure, but such a spring becomes larger as the external force increases, and the layout is increased. The above problem occurs, and it is necessary to push the fail-safe spring away to operate the arm length variable device.
In addition to requiring a large amount of power for operation, it is necessary to secure the expansion and contraction width of the spring, which results in a large device. However, in the structure of the present invention, the arm length varying device has a rotation drive mechanism and a conversion mechanism. Since the above problem is used, a compact device can be realized without causing the above-mentioned problems. (4) By forming the drive direction conversion mechanism between the output shaft and the rotary shaft by a screw type, the frictional force at the time of screwing the screw portion becomes a resistance, which is advantageous in fail-safe operation. (5) It is possible to adopt a configuration in which a planetary gear mechanism is used as the rotation drive mechanism. According to such a configuration, it is possible to set a large reduction ratio and change the arm length with a small control power. The arm length variable device can be made compact.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view of a main part schematically showing an arm length varying device of a suspension with an arm length varying device as one embodiment of the present invention.

FIG. 2 is a cross-sectional view (cross-sectional view taken along the line C-C of FIG. 1) showing a suspension with a variable arm length device as an embodiment of the present invention.

FIG. 3 is a cross-sectional view (cross-sectional view taken along the line AA of FIG. 1) showing a suspension with a variable arm length device as an embodiment of the present invention.

FIG. 4 is a cross-sectional view (cross-sectional view taken along the line BB in FIG. 1) showing a suspension with a variable arm length device according to an embodiment of the present invention.

FIG. 5 is a perspective view schematically showing an equipped state of an arm length varying device of a suspension with an arm length varying device as one embodiment of the present invention.

FIG. 6 is a diagram showing a detection unit that detects a rotation state of a rotation drive mechanism of a suspension with a variable arm length device according to an embodiment of the present invention.

FIG. 7 is a schematic cross-sectional view showing a modified example of the rotary drive mechanism of the suspension with a variable arm length device as an embodiment of the present invention.

[Explanation of symbols]

 1 Suspension with Variable Arm Length Device 2 Suspension Arm 3 Variable Arm Length Device 4 Arm Extension Mechanism 5 Rotation Drive Mechanism 6 Conversion Mechanism 7 Output Shaft 7A Groove 8 Rotation Shaft 8A Hole 9 Casing 9A Tip Opening 9B Cylinder (Oil Chamber) 9C, 9D Lubrication hole 9E Anti-rotation guide 9F Partition wall 10 Drive shaft 11 Vane 12 Bearing 13 Bearing 14 Carrier 15 Planetary gear 16 Sun gear 17 Ring gear 18 Bearing 19 Bearing 20 Detection means A Vehicle side B Wheel side S Planetary gear mechanism

Front page continuation (72) Inventor Takao Morita 5-3-8 Shiba, Minato-ku, Tokyo Mitsubishi Motors Corporation

Claims (1)

[Claims] 1. In a suspension provided for a vehicle, a suspension arm connecting a vehicle body side and a wheel side, and an arm length changing device which is incorporated in the suspension arm and can change a connection length between the vehicle body side and the wheel side. The arm length varying device includes an arm extension / contraction mechanism for extending / contracting the suspension arm in the arm length direction, a rotation drive mechanism equipped as an operation source of the arm extension / contraction mechanism, and a rotation by the rotation drive mechanism. A suspension with a variable arm length device, which is configured to include a conversion mechanism for converting the above into a telescopic operation of the arm telescopic mechanism.