JP2803873B2 - Vibration damping device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an improvement of a rotary-type vibration damping device mainly used for damping vibration of a rear wheel of a motorcycle.

(Related Art) A rear wheel of a motorcycle is attached to, for example, a swing arm freely swinging (rotating) supported on a vehicle body, and serves as a vibration damping device for attenuating vibration of the rear wheel between the vehicle body and the swing arm. The damper is interposed.

As such a damper, for example, a rotary damper as disclosed in JP-A-64-12152 is known.

This rotary damper defines an oil chamber between the vane rotating inside the rotary cylinder and the partition wall, and applies resistance to the hydraulic oil flowing out and in with the rotation of the vane to generate a predetermined damping force. It is to try to make it.

(Problems to be Solved by the Invention) However, such a hydraulic rotary damper has many technical problems in securing oil tightness between the rotary cylinder and the vane, and attenuated due to leakage of hydraulic oil. The force was likely to be unstable, and the processing cost was expensive.

To improve the riding comfort and driving characteristics of motorcycles,
Although the generated damping force needs to be appropriately controlled according to the driving conditions, the damping force characteristics of the rotary damper generally depend only on the swing speed of the swing arm, and the vibration position of the swing arm or the running speed of the vehicle or the road surface The damping force could not be changed according to the situation.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a rotary type vibration damping device that can be set to an arbitrary damping force characteristic according to operating conditions.

(Means for Achieving the Object) The present invention supports a wheel support member rotatably with respect to a vehicle body, and interposes the wheel support member between the wheel support member and the vehicle body. In a vibration damping device provided with a rotary damper for attenuating the relative rotation of the rotor, the rotary damper includes a rotating rotor, a stator that contacts the rotor to brake the rotation of the rotor, and a hydraulic piston that drives the stator. On the other hand, there is provided means for controlling the hydraulic pressure exerted on the hydraulic piston according to the operating state.

(Operation) When the wheel supporting member swings with respect to the vehicle body, the rotor and the stator relatively rotate. On the other hand, the hydraulic piston presses the stator in accordance with the supplied oil pressure, and the stator exerts a braking torque corresponding to the pressing force on the rotor to attenuate the swing of the wheel supporting member. In this case, since the hydraulic piston hardly slides and functions as a pressure transmitting member, the generated damping force changes with a good response to a change in supplied hydraulic pressure.

In addition, the control unit controls the hydraulic pressure supplied to the rotary damper according to the operating state, so that an optimal damping force characteristic can be obtained according to a request.

(Embodiment) FIGS. 1 to 8 show an embodiment of the present invention.

In this embodiment, a rotary damper is interposed between a vehicle body and a swing arm supporting a rear wheel of a motorcycle.
In the figure, reference numeral 1 denotes a swing arm, 2 denotes an axle of a rear wheel 4 supported at the tip of the swing arm 1, and 3 denotes a body of a motorcycle. In addition, a suspension spring (not shown) is interposed between the swing arm 1 and the vehicle body 3.

The base end of the swing arm 1 is rotatably connected to the vehicle body 3 via a rotary damper 5.

As shown in FIG. 2, the rotary damper 5 has a disk-shaped rotor 8 which is spline-coupled to a shaft 7 and is sandwiched between two disk-shaped stators 9A and 9B arranged on both sides, thereby producing a frictional force. The shaft 6 is spline-coupled to the vehicle body 3 and the stator 9A is fixed to the swing arm 1.
Fixed to The other stator 9B is case 6
Is supported toward the rotor 8 by a hydraulic piston 10 which is spline-engaged with the inner periphery of the shaft 7 and is slidably fitted to the shaft 7 in the axial and rotational directions. The rotor 8, the stators 9A and 9B, and the hydraulic piston 10 are all housed inside the case 6, and the case 6 is sealed by a flange 13. The shaft 7 rotatably passes through the case 6 and the flange 13 via a pair of bearings 12. An oil chamber 11 for urging the hydraulic piston 10 toward the rotor 8 is formed inside the case 6, a port 14 communicating with the oil chamber 11 is formed in the flange 13, and a port 14 is formed on the vehicle body side through the port 14. Oil chamber 11
A hydraulic pump 16 for supplying hydraulic pressure is mounted. Further, a spring 25 for applying an initial pressure to the hydraulic piston 10 is interposed between the hydraulic piston 10 and the flange 13 of the oil chamber 11.

On the other hand, in order to adjust the hydraulic pressure supplied to the oil chamber 11 according to the operating state and to optimally control the generated damping force, in this embodiment, the swing arm 1 is used as a means for detecting the swing displacement of the swing arm 1. A displacement detector 15 is interposed between the vehicle and the vehicle body 3. The displacement detector 15 includes, for example, a cylinder 15B and a telescopic piston rod 15A.
The displacement of the magnetic scale attached to 5A is detected by the magnetic sensor of cylinder 15B. Therefore, the displacement amount of the swing arm 1 can be obtained from the output, and the swing speed can be obtained from the differential value of the output.

A controller 19 and a servo valve 17 are provided as means for controlling the oil pressure supplied to the oil chamber 11 of the rotary damper 5 based on the signal output from the displacement detector 15.

The servo valve 17 selectively connects the hydraulic pump 16 and the tank 18 to the port 14, and is controlled by a command signal from the controller 19.

Further, the controller 19 obtains a predetermined damping force characteristic described later based on the displacement position of the swing arm 1 corresponding to the input signal from the displacement detector 15 and the displacement speed of the swing arm 1 obtained by differentiating the input signal. So that
A command signal is output to the servo valve 17 to control the oil pressure supplied to the oil chamber 11.

The controller 19 further receives a detection signal of a pressure sensor 20 that detects the actual oil pressure supplied to the oil chamber 11, and the controller 19 controls the servo valve 17 based on the pressure detected by the pressure sensor 20. The feedback controls the pressure in the oil chamber 11 to a target value with high accuracy.

A check valve 21 prevents backflow of hydraulic oil from the servo valve 17 to the hydraulic pump 16, an accumulator 22 for stabilizing a hydraulic pressure supplied from the hydraulic pump 16 to the servo valve 17 to a constant value, and a hydraulic pump 23. This is a relief valve that recirculates part of the discharge oil to the tank 18 when the discharge pressure of the pump 16 rises above a certain level.

 Next, the operation will be described.

When the swing arm 1 swings due to unevenness of the road surface during running, the case 6 fixed to the swing arm 1 and the shaft 7 connected to the vehicle body 3 rotate relative to each other inside the rotary damper 5, and the rotor 8 And stator 9A, 9B
And rotate relative to each other.

On the other hand, the hydraulic piston 10 applies a braking torque to the rotor 8 by pressing the stator 9B against the rotor 8 in accordance with the pressure in the oil chamber 11, and attenuates the swing of the swing arm 1.

This torque changes according to the oil pressure supplied to the oil chamber 11. That is, as shown in FIG.
When the pressure P is zero, only the initial torque based on the load of the spring 25 is applied to the rotor 8, and this torque is increased in proportion to the increase in the pressure P of the oil chamber 11, and the generated damping force of the rotary damper 5 is reduced. Enlarge.

Since the rotor 8, the stator 9B and the hydraulic piston 10 are already in light contact with each other with the pressure P being zero, the hydraulic piston 10 hardly displaces even if the pressure P rises, and the oil chamber 11
Functions as a member for transmitting the pressure P to the stator 9B.

Therefore, there is no danger of oil leaking from the oil chamber 11 due to the sliding of the hydraulic piston 10, and the torque exerted on the rotor 8 by the stator 9B changes very quickly in response to the change in the pressure P.

By the way, during traveling, the displacement detector 15 is
Oscillating displacement is detected and the corresponding displacement signal is sent to the controller
Continue to output to 19. On the other hand, the controller 19 differentiates the displacement signal to calculate the expansion / contraction speed of the displacement detector 15, and further calculates the swing angular velocity ω of the swing arm 1 from this value.
Is calculated. Then, the swing direction of the swing arm 1 is detected from the sign of the swing angular velocity ω, and the servo valve is adjusted so that the oil chamber 11 has a predetermined pressure P corresponding to the swing direction and the angular velocity ω.
Control 17 At this time, the pressure sensor 20 detects the pressure supplied to the oil chamber 11, outputs a pressure signal to the controller 19, and the controller 19 feeds back this pressure signal to the control of the servo valve 17, so that the oil chamber 11 Is accurately controlled in accordance with the angular velocity ω, and the influence of a temperature change or the like is eliminated.

Thus, the controller 19 and the servo valve 17 are
By controlling the pressure P of 11, the torque exerted on the rotor 8 by the stator 9B is controlled with extremely high precision.

For this reason, for example, FIG.
-By setting the pressure characteristics as shown in (C),
As shown in FIGS. 5 (A)-(C), the generated damping force on the extension side and the compression side can be arbitrarily controlled independently of each other.

As means for detecting the driving state, means for detecting the vehicle speed is provided, and the detected vehicle speed is input to the controller 19 to change the generated damping force corresponding to the vehicle speed V as shown in FIG. It is also possible to increase the damping force as the vehicle speed increases).

According to this, the stability of the running posture is enhanced by increasing the damping force in the high speed running range, and a soft ride comfort can be obtained in the low speed running range.

Further, the controller 19 calculates the swing angle θ of the swing arm 1 from the displacement signal input from the displacement detector 15, and changes the generated damping force corresponding to the swing angle θ as shown in FIG. As a result, a so-called position-dependent damping force can be generated.

Under such position-dependent damping force characteristics, fine vibrations near the neutral position are attenuated by weaker damping force, so that a soft ride can be obtained, while as the amplitude increases, the damping force increases. In addition, the stability of the vehicle body is not easily impaired even with a large shake.

Further, the controller 19 can detect the swing frequency f of the swing arm 1 based on the input signal from the displacement detector 15 and change the damping force according to this frequency as shown in FIG.

That is, when the frequency of the vibration input is high, the damping force is increased, and when the frequency of the vibration input is low, the damping force is reduced, thereby improving running stability and riding comfort.

In this embodiment, the rotor 8 of the rotary damper 5 is a single plate type.
It may be arranged alternately with B.

(Effects of the Invention) As described above, the vibration damping device of the present invention provides a rotary damper that generates a damping force by applying a braking torque to a rotor via a stator through a hydraulic piston, and exerts a hydraulic damper on the hydraulic piston according to an operation state. Since a means for controlling the oil pressure is provided, it is possible to perform damping force control with high responsiveness and to attenuate vibrations under various damping force characteristics such as a position-dependent type.

In addition, the part that generates the friction damping force and the part that presses it are composed of separate members, and the hydraulic piston can be made independent of the stator and the rotor. Is also excellent.

[Brief description of the drawings]

1 is a composite view of a schematic side view and a hydraulic circuit diagram of a main part of a vibration damping device showing an embodiment of the present invention, FIG. 2 is a sectional view of a rotary damper, and FIG. 3 is a hydraulic pressure supplied to the rotary damper. FIG. 4 is a graph showing a pressure characteristic of hydraulic pressure supplied to a rotary damper, and FIG.
FIG. 4 is a graph showing the characteristics of the damping force generated under the pressure characteristics of FIG. 4, FIG. 6 is a graph showing the damping force characteristics corresponding to the vehicle speed, and FIG. 7 is the damping force characteristics corresponding to the swing angle. FIG. 8 is a graph showing damping force characteristics corresponding to the swing frequency. 1 ... swing arm, 2 ... axle, 3 ... body, 4 ... rear wheel,
5 ... Rotary damper, 6 ... Case, 7 ... 0 shaft, 8
... rotor, 9A, 9B ... stator, 10 ... hydraulic piston, 11 ...
Oil chamber, 15 displacement detector, 16 hydraulic pump, 17 servo valve, 19 controller.

Claims (1)

(57) [Claims] 1. A rotary damper for rotatably supporting a wheel supporting member with respect to a vehicle body and interposing the wheel supporting member between the wheel supporting member and the vehicle body to attenuate relative rotation between the wheel supporting member and the vehicle body. In a vibration damping device comprising: a rotary damper comprising: a rotating rotor; a stator that contacts the rotor to brake the rotation of the rotor; and a hydraulic piston that drives the stator. A vibration damping device comprising means for controlling the operation according to the operating state.