JP2003267023A - Vibration damping running system for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To remove an effect of a low frequency region (20 to 50 Hz) and vibration of a small vehicle, in the small vehicle using a suspension system working also as a shock absorber for improving comfortableness by improving shock vibration of the vehicle. <P>SOLUTION: A fluid pressure gauge detects a linear movement amount following fluid movement, and a displacement signal limited only to a transaction amount from the shock absorber is inputted into a servo amplifier through a band-pass filter and a logarithm compression circuit, is amplified, and is transmitted to an actuator vibration damping device using the shock frequency part as a control signal. A displacement gauge is disposed as a sensor for detecting a movement amount to the actuator vibration damping device for monitoring and controlling a central position of a male screw, a direct current control signal is generated for it, and an objective frequency range is set at about 3 to 20 Hz. The actuator vibration damping device is mounted in series in the moving direction of the shock absorber for receiving the vibration, and the vibration transmission is limited to allow silent running. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle for carrying a person among small vehicles passing on roads having insufficient huts, many steps, manhole pavement, etc. It is intended for vibration control and shock absorption.

At an audible frequency, which is perceived as noise due to running of an automobile, it is hardly transmitted to the vehicle body due to anti-vibration rubber such as styrene-butadiene rubber or isobutylene-prene rubber, elasticity of elastic rubber wheels, and soundproofing equipment including the vehicle body. The function of the present invention is utilized in order to eliminate the impact vibration in the frequency range below the sound range that cannot be absorbed by the elastic rubber wheel.

[0003]

2. Description of the Related Art Vibration sources in automobiles are known to be engines, road surfaces, unbalanced rotating parts, meshing of gears, etc., and the vibrations generated at the sources are transmitted to the vehicle body via transmission paths such as drive systems and suspension systems. It is said that.

Causes of engine system vibration include engine vibration force, crankshaft torsional vibration, engine suspension system vibration, valve train system vibration, and the like. Torsional damper design, engine mount design, rubber In addition to being supported by material design, etc., it is 200-500 when classified by frequency.
The vibration transmission system is used for Hertz, and the sound absorbing and insulating material is used for 500 Hertz and above.

In addition, when operating a vehicle, there are many unpaved roads that hinder ride comfort, many steps, and manhole paving is insufficient. The cause is that the tire receives displacement displacement due to the unevenness of the road surface, which causes vibration of the suspension system and is transmitted to the vehicle body.
There is a muffled sound of 50 hertz. Especially 3 to 20
The area of Hertz is often anxious for people with physical disabilities and elderly people, so we laid a lead plate in the rear trunk room to increase the weight and resisted transmission of high frequency components to the body part. There was an example of devising to prevent it.

[0006] Conventionally, a suspension device used in a general vehicle has a spring material and a fluid type shock absorber (shock absorber).
It consists of a combination of two functions. The spring receives the vibration input from the wheels, but when there is a quick and sharp vibration impact, a stress concentration part may occur before the expansion and contraction of the spring is transmitted to the whole spring, and it may break. Dynamic component, high frequency region, large amplitude displacement input,
A shock absorber is used to prevent breakage of the spring material. In fact, shock absorbers
In the impact area (high frequency component) received from the road surface, there is a characteristic that the rigidity force increases.

As the performance of a vehicle is improved, the shock absorber is required to have a higher function as a component of active control or a complicated valve mechanism in order to further enhance a conventional damper function. In addition to the frequency-sensitive type and stroke-sensitive type, the shock absorber damping force control has also been introduced, and the damping force of the four shock absorbers mounted on each of the front and rear suspensions can be adjusted according to the running condition of the vehicle. It automatically switches to achieve both riding comfort and steering stability.

[0008]

In order to improve the shock and vibration of the vehicle and improve the riding comfort of the vehicle, an air spring has been tried in the past for the improvement. However, since it requires a complicated function, it is a large vehicle. It was used for a limited number of purposes. However, as long as it is a suspension system that also uses a shock absorber at the same time, it is inevitable to eliminate the influence in the low frequency region (3 to 20 Hertz).

Generally, it is more difficult for a vehicle to remove vibrations as a smaller vehicle, but normally a rubber tire is used for operation, and the fuel consumption efficiency greatly varies depending on the amount of air pressure of the tire used, and the pressure is different. As the fuel consumption rises to a certain level as the fuel consumption rises, on the other hand, the tension of the rubber increases and the elasticity increases, making the ride less comfortable, so eliminating vibration from small vehicles is an important issue. Has become.

[0010]

SUMMARY OF THE INVENTION The present invention has been proposed to solve the above-mentioned problems, and is incorporated as a device for reducing vibration mainly at a small vehicle in which vibration is difficult to remove, at a low cost. It is a vibration damping traveling system for vehicles.

Referring to FIG. 2 in detail, FIG.
1 is a schematic view of a vibration damping traveling system for a vehicle, in which a piston 25 of a shock absorber 12 arranged on a wheel 14 of a vehicle via a pivot 13 is fixed and built in the shock absorber 12, and is connected to the shock absorber 12. Installed electric or hydraulic actuator damping device 1
5 is fixed to the vehicle body 20, and the hydraulic pressure gauge 10 for detecting the linear momentum associated with the fluid movement in the shock absorber 12 is provided side by side with the shock absorber 12, and the displacement signal 29 limited only to the AC component from the shock absorber 12 is provided. Is a bandpass filter 18 and a logarithmic compression circuit 1
Input to the servo amplifier 16 via 7, and after amplification and expansion,
Only the impact frequency is used as the control signal 21 and transmitted to the actuator damping device 15, while the displacement gauge 6 as a sensor for observing the amount of movement of the male screw 5 to the actuator damping device 15 for the central position monitoring control is placed. Separately, the DC component control signal 22 for maximizing the dynamic range 9 is created, and the target frequency range is approximately 3 to 20 hertz. A vehicle that can be adapted from a small vehicle for attaching an electric or hydraulic actuator damping device 15 in series in the movement direction of the shock absorber 12 to which high-frequency vibrations are transmitted, and restricting vibration transmission for quiet running Vibration damping traveling system for an actuator
Although 5 is mainly an electric type, if the cost is ignored, hydraulic pressure or the like can be used, and it can be integrated with a shock absorber.

Further, the shock absorber 12 has a piston 25 in the middle of the two chambers, and a fluid 28 is connected from one to another chamber by a closed circuit, and when the position of the piston 25 moves, it is in the middle of the passage of the closed circuit. A fluid throttle valve 36 is provided, and by utilizing the fluid resistance when the fluid 28 passes through, the fluid throttle valve 36 is adjusted to determine the good points of both riding comfort and vehicle body protection, and a damping absorption (critical damping) state is established. On the other hand, the relationship between the vehicle body weight and the spring constant has a constant natural frequency, and the amplitude at the time of inputting a specific vibration causes the amplitude to diverge, and the amplitude when the traveling becomes unstable can be promptly changed by the resistance of the shock absorber 12. It is a vehicle vibration damping traveling system having a function of damping and absorbing, and in terms of force transmission characteristics, it performs differential operation except friction resistance.

Further, the vertical movement of the vehicle axle is
It transmits to the spring 11 and the shock absorber 12 through the shaft fulcrum 13 of the wheel 14, and the end of the spring 11 is the body structure part 27.
The upper part of the shock absorber 12 is directly connected to the male screw 5 of the actuator 15 and is fixed in the radial direction so as not to rotate, and the female screw 26 that rotates corresponding to the male screw 5 is a motor. It is a vibration damping traveling system for a vehicle, which is fixed to the rotor 7 and the side of the stator 8 of the motor is fixed to the vehicle body 20 and is interlocked with a shift lever or the like as a switching device.

As a function of the structural portion of the vehicle body, an electric actuator vibration damping device for the actuator vibration damping device 15 to absorb a shock will be described as a detailed embodiment as follows.

The shock absorber 12 and the vehicle body 20 are separated from each other at the joint, and the male screw 5 for linear movement is placed in the middle. The female screw 26 corresponding to the male rod 5 is directly connected to the rotor 7 of the motor, and the rotor 7 of the motor. Is fixed in the axial direction so as not to move in the thrust direction. When the motor rotates in the radial direction, the structure is such that the female screw 26 rotates in accordance with the pitch of the male screw 5 to make a linear motion in the thrust direction. There is. Motor stator (stator)
The 8 side is connected and fixed to the vehicle body 20.

To grasp the characteristics of the vibration source for vibration control,
If you investigate the transmission path, clarify the vibration transmission characteristics, and cope with the vibration suppression technology at a place near the vibration source, the vibration will not spread and the countermeasure area can be limited to a narrow range. Displacement, velocity, and acceleration are used, but holographic measurement is used to grasp a wide range of amplitude distribution in a short time, and it is used to measure the vibration amplitude of complicated engine outer walls and body skins.

The relationship between the vehicle body weight and the spring constant has a theoretically constant natural frequency, and when a specific vibration is input, the amplitude diverges (becomes larger gradually) and the running becomes unstable. Due to the resistance of the shock absorber 12, the amplitude at that time has a function of promptly absorbing and absorbing (critical damping).

In addition to the natural frequency of the vehicle body, vibration is transmitted from the road surface through the wheels depending on the road traveling condition, and as the vibration frequency increases, the rigidity becomes dominant and is transmitted to the vehicle body. As a result, shock vibrations are transmitted to the vehicle body in response to the unevenness of the road surface, and the ride comfort is poor when passing over unpaved roads or manhole covers.

When the vehicle is stationary, the shock absorber 12 is in a state of zero repulsion force, and the male screw 5,
The force relationship between the female screws 26 is zero. (Actually, there is some reaction force due to friction, etc.). That is, all the loads are supported by the repulsive force of the compression spring, and the positional relationship of the male screw 5 is controlled so as to be in the center of the moving range of the actuator damping device 15. This maximizes the dynamic range 9 in the vertical direction (almost the middle of the moving range of the actuator mechanism).

Explaining the limiting elements, a hydraulic pressure gauge (proportional to displacement) 10 is provided as a sensor for detecting the linear momentum of the shock absorber 12, and a motor control deviation signal amplifier (servo amplifier) 16 is further provided. A displacement gauge 6 as a sensor for observing the movement amount of the actuator damping device 15 (for controlling the central position of the feed screw 5) is provided.

Explaining the control circuit, the displacement signal 29 transmitted to the actuator damping device 15 is a signal (only AC component) from the shock absorber 12 which is servo-controlled via the bandpass filter 18 and the logarithmic compression circuit 17. After input to the amplifier 16 and amplified and expanded, only the impact frequency is used as the control signal 21. In addition, a control signal (DC component) for maximizing the dynamic range 9 separately.
Is making.

To explain the operation, in a steady state, the male screw 5 is at the maximum of the dynamic range 9, and prior to traveling, the shift gear is at the position of the parking P, and at the static load value, the function of the proportional differentiating circuit 19 causes the initial low speed follow-up. However, if the deviation disappears, it will stop. In this case,
The shock absorber 12 is supposed to move its position by the actuator damping device 15.

The shift gear is switched to the position of the traveling D, the traveling is started, the vibration frequency in a specific range is corrected, and the actuator damping device 1 is controlled by the servo amplifier 16.
It is supposed to be automatically controlled so as to be transmitted to No. 5 and absorb the shock vibration.

The pass frequency band of the bandpass filter 18 is set in the range of about 3 hertz to 20 hertz.
It is decided to make some adjustments based on the overall performance after experiencing it in an actual vehicle. Correct the characteristics of the servo amplifier,
Even if the vehicle body vibration prevention control is not set as the zero target, it is possible to sufficiently demonstrate the practicality.

In the frequency region other than that defined by the bandpass filter 18 (slow vibration and high frequency that is felt as sound), the control absorber becomes insensitive and the original function of the shock absorber 12 is not impaired.

The control will be described in detail. When the actuator damping device 15 completely follows the vibration shock input, it is equivalent to the state where the function of the shock absorber 12 does not work. Since the high frequency range is up to the vibration frequency range that the actuator damping device 15 can follow (resulting in a bandpass filter), the operation range is limited, and the dynamic range 9 is corrected by the limitation of the logarithmic compressor 17 that is the range. It controls the transmission amplitude to the vehicle body.

Since improving the performance, that is, improving the riding comfort, is closely related to the follow-up speed of the actuator damping device 15, the shock absorber 12 is naturally required.
It is necessary to reduce the inertia of the correction operation mechanism part including, to output a large output power for driving the motor, and to improve the following speed. Moreover, components that are now sufficient electronic components are readily available.

The male screw 5 does not function against the vibration direction of the vibration impact but escapes (forward direction).
If a screw with a small feed angle and a small friction coefficient value is selected, the tracking response will also improve, and the output power will be
A small amount of power is enough.

According to a running test, in this case, the starting position, the stopping position, the construction site, and the like are out of the band because of the low speed region, and the actuator damping device 15 is in the stopped state because of the dead region. ± 8 at maximum for the target vibration displacement
A thickness of 0 mm is to provide good riding comfort and results that fulfill the full function of this purpose.

Explaining in the block diagram of the control system of the vehicle vibration damping device of FIG. 1, the target value V of the vibration θ is input to the servo amplifier 1 and further the actuator 2 to be controlled.
To the control input X as well as the vibration input U as a disturbance.
Is output to the shock absorber 3 serving as a detection unit, signal-processed, fed back as negative feedback μ, added to V, and again loop gain G
transmitted by o.

The control system takes the form of the following formula.

[Equation 1]

Closed-circuit controlled variable X caused by disturbance U
Is

[Equation 2]

Explaining with the diagram of the actuator damping device 15 following the parking position in FIG. 3, the relationship between the displacement gauge 6 and the following action of the actuator damping device 15 in the feedback loop passing through the proportional differentiation circuit 19 is shown in FIG. Integral tracking follows as shown in FIG. The time (t) is determined according to the differential circuit constant D. In this case, the amplification factor P of the servo amplifier 16 is assumed to be infinitely large, and correction is performed until the deviation signal becomes zero.

Explaining with reference to the control characteristic diagram during traveling shown in FIG.
With the response (between 3 and 20 Hertz) in the case of running D designated position,
The response delay 34 affected by the mass M and the amplitude limit amount 35 by the logarithmic compression circuit are as shown in FIG.

[0036]

EFFECTS OF THE INVENTION According to the present invention, normally, a rubber tire is used for driving, the tension of the rubber is increased, the elasticity is increased,
It has been an important issue to eliminate vibrations of small vehicles that make the ride uncomfortable, but the vibration damping traveling system that can be incorporated reduces vibrations at a low price, mainly for small vehicles where vibrations are difficult to remove. Comfort as a device is improved,
The fuel efficiency was improved at the same time.

When operating the vehicle, vibrations in the high frequency range, which are perceived as noise, are prevented except for unpaved roads that hinder ride comfort, many bumps, and parts with insufficient manhole paving. Although it is hardly transmitted to the vehicle body due to the elasticity of the rubber and elastic rubber wheels, it is avoided from removing the effects in the low frequency range (3 to 20 Hertz), which is most uncomfortable for the occupant as long as it is a suspension system that also uses a shock absorber. The tire receives displacement displacement due to the unevenness of the road surface, which causes vibration of the suspension system and is transmitted to the vehicle body.
A muffled sound of 0 hertz) was generated, which was often annoying to people with physical disabilities and elderly people, but to eliminate shock vibrations in the frequency range below the range that elastic rubber wheels cannot absorb. Is now possible.

[Brief description of drawings]

FIG. 1 is a block diagram of a control system of a vehicle vibration damping device.

FIG. 2 is a schematic diagram of a vibration damping traveling system for a vehicle.

FIG. 3 is a view of the actuator following the parking position.

FIG. 4 is a control characteristic diagram during traveling.

[Explanation of symbols]

1: Servo amplifier 2: Actuator 3: Shock absorber 4: Signal processing 5: Male Neji 6: Displacement meter 7: Motor rotor 8: Stator of motor 9: Dynamic range setting device 10: Liquid pressure gauge 11: Bane 12: Shock absorber 13: Shaft fulcrum 14: Wheel 15: Actuator damping device 16: Servo amplifier 17: Logarithmic compression circuit 18: Band pass filter 19: Proportional differentiation circuit 20: Car body 21: Control signal 22: DC component control signal 23: AC component signal 24: Deviation signal entrance 25: Piston 26: female cat 27: Body structure section 28: Fluid 29: Displacement signal 30: Maximum point of dynamic range 31: Vibration input 32: Body transmitted vibration (u-x) 33: Actuator operation amount 34: Phase delay time difference 35: Insufficient amount of vibration correction 36: Fluid throttle valve D: Running P: Parking

Claims (2)

[Claims] 1. A shock absorber is provided with a piston provided on a wheel of a vehicle via a shaft fulcrum, and an electric or hydraulic actuator damping device is fixed to the vehicle body by being connected to the shock absorber. A hydraulic pressure gauge that detects the linear momentum associated with the fluid movement inside the shock absorber is installed adjacent to the shock absorber, and the displacement signal limited to only the alternating current component from the shock absorber is
Input to servo amplifier via bandpass filter and logarithmic compression circuit, and after amplification and amplification, only impact frequency is used as control signal and transmitted to actuator damping device,
Displacement sensor as a sensor to see the amount of movement to the actuator vibration control device for central position monitoring control of the male screw is placed, and a control signal (DC component) is set separately to set the maximum dynamic range, and the target frequency is set. The range is approximately 3 to 20 Hertz. An electric or hydraulic actuator damping device is installed in series in the direction of movement of the shock absorber to which high frequency vibrations are transmitted. A vibration-damping drive system for vehicles to limit and drive quietly. 2. A vertical movement of an axle of a vehicle is transmitted to a spring and a shock absorber through a fulcrum of a wheel, a terminal of the spring comes into contact with a vehicle body structural portion to support a load, and an upper portion of the shock absorber is provided with an actuator. Directly connected to the male screw, fixed in the radial direction to prevent rotation, the female screw that rotates corresponding to the male screw is integrated with the rotor of the motor, and the rotation shaft is fixed so that it does not move in the thrust direction. The vibration damping drive system for the vehicle, where the stator side of the motor is fixed to the vehicle body structure.