JPH0541452B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a vehicle vibration control device for suppressing vehicle body vibrations excited by fluctuating torque disturbances from a vehicle engine.

[Prior art]

One of the important technical issues for vehicles such as automobiles is the pursuit of comfortable vehicles such as ride comfort with regard to vibration. Conventionally, in order to improve ride comfort, efforts have been made to reduce vehicle body vibration by installing damping force control devices for the shock absorbers that support the vehicle body, and by adding vibration absorption functions to the mount mechanism that supports the engine. We are trying to However, with a horizontally mounted engine and an FF (front engine, front drive) system, the engine's drive reaction torque is particularly large, and because its direction matches the direction of vibration of the vehicle body, the fluctuating torque from the engine is transmitted through the engine mount. , the problem of excessive vibration of the vehicle body comes to light. The engine mount is the contact point between the engine and the vehicle body, and there are many issues to consider when designing it, and the following conflicting conditions must be satisfied. In other words, in areas where drive reaction torque is large, the engine mount must be rigid in order to limit the displacement of the engine and exhaust system such as the muffler.
In idling and medium to high speed ranges where torque is relatively small, the mount needs to have low rigidity to provide vibration isolation. It is extremely difficult to achieve these contradictory conditions at a high level.
Furthermore, if the natural frequency of the bending mode vibration of the vehicle body is close to or coincides with the idling speed range, there is a problem that the vibration of the vehicle body becomes extremely large and the riding comfort deteriorates. Reducing vehicle body vibration, including the engine mount, is an important technical issue in improving vehicle ride comfort and comfort. In particular, in vehicles that use a FF drive system with a horizontally mounted engine, the natural frequency of the vehicle body is close to or exists in the idling speed range, and furthermore, the direction of fluctuating torque matches the direction of vibration of the vehicle body. Excessive vibrations were excited in the car body, and the ride quality and comfort were significantly reduced.

Figure 1 shows the mechanism by which body vibrations occur in a vehicle. In the figure, 1 is an engine, 2 and 3 are a front engine mount that elastically supports the front and rear parts of the engine 1, a rear engine mount, 4 is a vehicle body, and the engine 1 is mounted on the vehicle body 4 via both engine mounts 2 and 3.

The engine 1 in the horizontal engine vehicle has a plurality of cylinders, and the cylinders are arranged in a direction transverse to the vehicle body 4, that is, in a direction perpendicular to the longitudinal direction. For this reason, when the engine is driven, the behavior of the engine 1, as shown by the arrows in FIG. 1, is dominated by the excitation of rocking vibrations about the drive shaft as the center of rotation in response to torque due to pressure fluctuations in the cylinder. On the other hand, the vibration characteristics of the vehicle body 4 include a natural frequency (usually about 25 Hz) at which the entire vehicle body vibrates in an elastic mode in which it bends and deforms, as shown by the broken line in FIG. In particular, the frequency of engine 1 rocking vibration and the car body 4
In the idling speed range where the natural frequency of Comfort and comfort deteriorate, causing physical and mental pain to passengers.

[Summary of the invention]

The present invention was made in view of this problem, and includes an actuator that detects a fluctuating torque disturbance applied to the vehicle body from the engine and applies a damping force to the vehicle body to cancel out the fluctuating torque disturbance. An object of the present invention is to provide a vehicle vibration control device that can actively reduce vehicle body vibration.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings. In FIG. 2, the same parts as in FIG. 1 are designated by the same reference numerals, and their explanation will be omitted. 5 is a seat installed on the vehicle body 4. 6 is an actuator attached to the vehicle body 4; 7 is a vibration sensor fixed to the vehicle body 4 for detecting vibration acceleration; and 8 is a control circuit that receives a signal from the vibration sensor 7 and drives the actuator 6.

FIG. 3 shows a block diagram of the control circuit 8, in which 81 is a vibration detection circuit, 82 is an arithmetic circuit, and 83 is a vibration detection circuit.
is the drive circuit. That is, the vibration of the vehicle body 4 detected by the vibration sensor 7 is transmitted to the vibration detection circuit 8.
1, the signal is amplified as an electrical signal and input to the arithmetic circuit 82. The arithmetic circuit 82 is an electric circuit having predetermined gain and phase characteristics, and adjusts the gain and phase of the signal and transmits it to the drive circuit 83. Drive circuit 83
supplies electric power to generate a damping force that drives the actuator 6.

FIG. 4 is a configuration diagram showing an embodiment in which an electrodynamic linear actuator is applied to the actuator 6.
61 is a permanent magnet, 62 is a cylindrical yoke, 63 is a coil, 64 is a coil support that supports the coil 63, 65 is a support spring that is disposed at the upper and lower ends of the yoke 62 and holds the yoke 62, and 66 is the yoke 62.
The guide rod 67 passing through the yoke 62 is a slide bearing fixed to the upper and lower ends of the yoke 62.
6, and the yoke 62 is linearly driven in the vertical direction. 68 is a casing. To explain the operation of the above linear actuator, the permanent magnet 61 is magnetized in the radial direction and fixed to the yoke 62, forming a magnetic circuit and forming the coil 62.
A predetermined magnetic flux density occurs in the gap where the magnetic flux is inserted.
As a result, when a drive current is supplied to the coil 62 from the drive circuit 83, an electromagnetic force is generated between the coil 63 and the permanent magnet 61 due to electromagnetic action. At this time, the electromagnetic force generated in the coil 63 based on the principle of action and reaction is transmitted to the casing 68 fixed to the vehicle body 4 via the coil support 64 and acts on the vehicle body 4. On the other hand, the electromagnetic force generated in the permanent magnet 61 is balanced by the sum of the restoring force of the support spring 65 that supports the yoke 62 and the inertial force of the yoke 62 and the permanent magnet 61.

The above mechanical model is shown in FIG. 9 is an additional mass that is the sum of the masses of the yoke 62 and the permanent magnet 61;
The support spring 65 has a spring constant Rd. Also, U is the electromagnetic force acting between the coil 63 and the permanent magnet 61,
A damping force T, which is the sum of the electromagnetic force U and the restoring force of the support spring 65, acts on the vehicle body 4. Also, the support spring 6
5 serves to ensure the neutral position of the yoke 62.

Next, the vibration reduction principle will be explained. The vibration reduction principle of the device according to the present invention is based on an equation of motion that is established when a variable torque disturbance and damping force from the engine 1 act on the vehicle body 4.

MsX ¨s + Ks The vibration damping force U generated by the actuator 6 is applied to the vehicle body 4 by the control circuit 8 in accordance with the signal detected.
This indicates that the voltage is to be applied to the vibration system. Also,
Based on mechanical considerations, damping force U can be expressed as vibration acceleration X...S, vibration speed X^・s, and vibration displacement of the vehicle body 4.
It can be seen that by making the force proportional to Xs, the equivalent mass, damping, and equivalent rigidity of the vehicle body 4 can be controlled.

FIG. 6 shows the arithmetic circuit 82 of the control circuit 8. In the figure, 82a, 82b, 82c are integrators, 82d is a high-pass filter with a cutoff frequency of ω ₂ ,
82e is a band filter that passes frequencies in the ω ₁ and ω ₂ regions, 82f is a reduction filter with a cutoff frequency of ω ₁ , and 82g is an adder. A vibration acceleration signal of the vehicle body 4 detected by the vibration sensor 7 is amplified by a vibration detection circuit 81 and input to an arithmetic circuit 82 . One of the vibration acceleration signals of the vehicle body 4 inputted to the arithmetic circuit 82 is passed through a high-pass filter 82d as it is, and frequency components lower than ω ₂ are removed and transmitted to an adder 82g. on the other hand,
One signal branched from the vibration acceleration signal is converted into a signal proportional to the vibration speed by an integrating circuit 82a, and then passed through a band filter 82e to remove frequency components outside the range of ω ₁ and ω ₂ . Furthermore, the acceleration signal is converted into a signal proportional to the vibration displacement via integrators 82b and 82c, and then passed through a reduction filter 82f to remove frequency components higher than ω ₁ and transmitted to an adder 82g. The adder 82g adds these vibration acceleration, velocity, and displacement signals and outputs them as input signals to the drive circuit 83, so that the cutoff frequency ω ₁ ,
ω ₂ becomes as follows. In other words, the natural angular frequency ω _o of the vehicle body 4 is The cutoff frequencies ω ₁ and ω ₂ are generally required to be set to satisfy ω ₁ =0.707×ω _o (3) ω ₂ =1.414×ω _o (4). With this configuration, the high frequency filter 8
The actuator 6 is vibrated via the drive circuit 83 by the vibration acceleration signal that has passed through 2d, and a damping force proportional to the vibration acceleration is generated. This damping force acts to apparently increase the equivalent mass Ms of the vehicle body 4. The signal passing through the band filter 82e causes the actuator 6 to generate a damping force proportional to the vibration speed of the vehicle body 4, and this damping force acts to apparently improve the damping characteristics of the vehicle body 4. Further reduction filter 8
The signal passing through 2f generates a damping force proportional to the displacement of the vehicle body 4, and this damping force increases the equivalent rigidity of the vehicle body 4.

FIG. 7 schematically shows the effect of reducing vehicle body vibration by the control of the present invention. In the figure, the solid line represents the vibration characteristics of the vehicle body 4 without control, and the broken line represents the vibration characteristics of the vehicle body when the device of the present invention is installed. The damping force based on vibration displacement is effective in a region lower than the resonance frequency of the vehicle body 4, and vibration reduction is achieved by increasing the equivalent rigidity of the vehicle body 4. Further, the damping force based on the vibration speed exhibits a vibration reduction effect near the resonance frequency of the vehicle body 4, and the damping effect on the vehicle body 4 reduces the resonance peak. Furthermore, the damping force based on vibration acceleration is effective in a region higher than the resonance frequency of the vehicle body 4, and vibration reduction is achieved by increasing the equivalent mass. As a result, the vibrations of the vehicle body 4 can be reduced over a wide range of frequencies from low frequencies to high frequencies, and the vibrations of the vehicle body can be extremely reduced.

In the above embodiments, an electrodynamic linear actuator is used as the actuator, but the same effect can be obtained even if the actuator is a pneumatic or hydraulic actuator.

〔Effect of the invention〕

As explained above, according to the present invention, there is provided an actuator attached to a vehicle body that generates vibration in response to fluctuating torque disturbance from the engine, a vibration sensor that detects the vibration acceleration of the vehicle body, and a detection signal from the sensor that is based on a detection signal from the sensor. Since the control circuit is equipped with a control circuit to drive the actuator, it is possible to use the damping force generated by the actuator to extremely reduce vibrations in the vehicle body, thereby improving the ride quality and comfort of the vehicle. There is an effect that can be done.

[Brief explanation of the drawing]

Figure 1 is a diagram showing the vibration generation mechanism of a vehicle.
FIG. 2 is a block diagram of a vibration control device showing an embodiment of the present invention, FIG. 3 is a block diagram of a control circuit, and FIG.
5 is a sectional view showing an example of an actuator, FIG. 5 is a diagram of a mechanical model of the actuator, FIG. 6 is a block diagram of an arithmetic circuit, and FIG. 7 is a diagram of vibration characteristics of the vehicle body. DESCRIPTION OF SYMBOLS 1... Engine, 4... Vehicle body, 6... Actuator, 7... Vibration sensor, 8... Control circuit, 82a, 8
2b, 82c...integrator circuit, 82d...high frequency filter, 82e...band filter, 82f...reduction filter, 82g...adder. In addition, in the figures, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] 1 An actuator mounted on a vehicle body that generates vibrations in response to fluctuating torque disturbances from an engine, a vibration sensor that detects vibration acceleration of the vehicle body, and a control circuit that vibrates the actuator based on a detection signal from the vibration sensor. The control circuit includes a first integrating circuit that converts the vibration acceleration into a vibration velocity, a second integration circuit that converts the vibration acceleration into a vibration displacement, and a signal obtained by passing the vibration acceleration through a high-pass filter. A vibration control device for a vehicle, comprising: an addition circuit that adds a signal obtained by passing the vibration velocity through a band filter and a signal obtained by passing the vibration displacement through a low-pass filter, and adds the sum to the actuator.