JPS61207212A - Vibration controller for vehicles - Google Patents

Abstract

PURPOSE:To reduce vibrations in a car body with a small-sized actuator as well as to improve a feeling of driving comfortableness so better, by detecting these vibrations in an engine and the car body and driving the actuator, then giving damping force to the car body. CONSTITUTION:The varying torque disturbance of an engine 1 detected by a vibration sensor 7 is taken out as an electric signal and inputted into a control part 8. Then, gain phase of this electric signal is regulated by a circuit having the specified gain phase characteristic and power for driving an actuator 6 is fed to it. In addition, damping force to be produced out of the actuator 6 is impressed in a direction of damping vibrations in a car body 4, and vibrations in the car body 4 are positively reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field 1] The present invention relates to a vehicle vibration control device that suppresses vehicle body vibrations caused by engine vibrations.

[Background Art] One of the important technical issues in vehicles such as automobiles is the pursuit of comfortable vehicles that have excellent ride comfort and are resistant to vibration.

In order to improve this ride comfort, we have taken measures such as installing a damping force control device for the shock absorber that supports the vehicle body, and adding a vibration absorption function to the mount mechanism that supports the engine to reduce vehicle body vibration. I'm trying.

However, with a horizontally mounted engine, FF (front engine,
With the front drive (front drive) system, the driving reaction torque of the engine is particularly large and its direction coincides with the direction of vibration of the vehicle body, so the fluctuating torque from the engine is transmitted via the engine mount, causing excessive vibration of the vehicle body. The problems that occur come to the surface.

Therefore, the engine mount must satisfy the following conditions.In other words, in areas where the drive reaction torque is large, the engine mount must be rigid in order to limit the amount of displacement of the engine and exhaust system such as the muffler. In the idling and medium-to-high rotation ranges where the torque is relatively small, the mount needs to have low rigidity with the main purpose of vibration isolation. It is extremely difficult to achieve these conflicting conditions in a high-dimensional manner, and if the natural frequency of the bending mode vibration of the car body is close to or coincides with the fitting rotational speed range, the vibration of the car body becomes large.
There may be a problem with the ride comfort. Here, reducing vehicle body vibration, including the engine mount, improves vehicle ride comfort.
These are 71 technical issues that are important for improving 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 the fluctuating torque coincides with the vibration direction of the vehicle body. Excessive vibrations were excited, and there was a significant deterioration in ride quality, ground comfort, etc.

Figure 6 shows the vehicle body vibration generation mechanism.
(ri is the engine, (2) is the front engine mount that elastically supports the front side of the engine, (3) is the rear engine mount that supports the rear side, (4)
is the vehicle body, and the engine (1) is the engine mount (
2) and (3) are attached to the vehicle body (4). By the way, in a horizontal engine, the engine (1) has multiple cylinders.

The arrangement is perpendicular to the direction transverse to the vehicle body (0), that is, the longitudinal direction. Therefore, the engine (1) behaves in the direction of the arrow, receiving fluctuating torque due to pressure fluctuations in the cylinder, and rotating around the drive shaft. This excites rocking vibrations.

The vibration characteristics of the car body (4) include the natural frequency (
For example, there is a frequency of 25Hz (=1500 times/min).

In particular, in the idling speed range where the frequency of the rocking vibration of the engine (1) and the natural frequency of the vehicle body match or are close to each other (for a 4-cylinder engine, 1200 to 1600 explosions/
(2005), the vehicle body is excited by an excessive movement due to resonance, which transmits vibrations to the seats, reducing ride quality and comfort, and causing physical and mental pain to the occupants.

On the other hand, prior to filing this application, the present applicant provided a vibration control device for suppressing vibrations of structures such as bridges (for example, Japanese Patent Laid-Open No. 57-041093).

The above-mentioned vibration control device detects the vibration of the object to be suppressed, operates the damping device based on this detection output, and actively applies vibration control force according to the vibration properties of the object structure. Realizes vibration reduction of objects.

[Problems to be Solved by the Invention] However, a vibration damping device that effectively suppresses the vibrations of a vehicle described above has not yet been realized, and even if the vibration control device of the above publication is applied to a vehicle as is, In order to obtain a large damping force using the above-described damping device, the damping device must be large in size, which is particularly disadvantageous when installed in an automobile with limited space.

This invention was made with the aim of improving this drawback, and is designed to detect engine vibrations or vibrations acting from the engine on the vehicle body, drive an actuator based on the detection, and cancel the vibrations by driving the actuator. The object of the present invention is to provide a vibration control device for a vehicle that not only reduces vibration of the vehicle body and improves riding comfort and comfort by applying control force to the vehicle body, but also reduces the size of the actuator described above. That is.

[Means for Solving the Problems] A vibration control device for a vehicle according to the present invention includes a vibration sensor that detects vibrations of an engine or a vehicle body, a movable mass object attached to the vehicle body via an elastic body, and a vibration control device for a vehicle according to the present invention. an actuator that is connected between the mass object and the vehicle body and has a vibration damping drive section that applies a damping force to the vehicle body based on a detection signal from the vibration sensor; and an actuator that drives the actuator based on the detection signal from the vibration sensor. and a control section, and the natural frequency of the vibration system made up of the movable mass object of the actuator and the elastic body is set lower than the natural frequency of the vehicle body.

[Function] In this invention, by setting the vibration frequencies in a specific relationship as described above, a damping force is generated that is amplified with respect to the driving force of the actuator, thereby effectively suppressing the vibration of the vehicle body. be done.

[Example] An example of the present invention will be described below with reference to the drawings.

In FIG. 1, the same reference numerals as in FIG. 6 indicate the same parts, so the explanation will be omitted.

In Figure 1, (7) is a vibration sensor, which is connected to the engine (1).
is installed at the top of the. Reference numeral (8) denotes a control section, which, as shown in the block diagram shown in FIG. 2, consists of a preamplifier (81), a control circuit (82), and a drive circuit (83).

(6) in FIG. 1 is an actuator, which is installed at the front end of the vehicle body (4). (5) is the seat.

Here, the fluctuating torque disturbance of the engine (1) detected by the vibration sensor (7) in FIG. 2 is extracted as an electrical signal and input to the preamplifier (81). The signal amplified by .

It is input to the control circuit (82). The control circuit (82) is
A circuit with predetermined gain and phase characteristics adjusts the gain and phase of the electrical signal and transmits it to the next drive circuit (83).

The drive circuit (83) supplies power for driving the actuator (6), thereby applying the control force generated from the actuator (6) to the vehicle body (4).
) can be applied in a direction that suppresses the vibrations of the vehicle body (4), thereby actively reducing the vibrations of the vehicle body (4).

The actuator (6) is configured as shown in Figure fiIJ3.

In other words, the actuator (6) in this case is an electrodynamic linear actuator, and in the figure, (81) is a permanent magnet (vibration damping drive part), (82) is a cylindrical yoke, and (63) is a permanent magnet (vibration damping drive part). is a coil (vibration damping drive part), (64)
is a coil support that supports the coil (83)), (8
5) Elastic bodies (springs) disposed at both upper and lower ends of the yoke (82) to support the yoke.

(88) is a guide rod, (87) is a slide bearing fixed to the upper and lower ends of the yoke (82), and this bearing (67) slides along the guide rod (88).

The yoke (62) is driven in the vertical direction. (88)
is the casing. To explain the operation of the electrodynamic linear actuator, the permanent magnet (61) is magnetized in the radial direction and is fixed to the yoke (82) to form a magnetic circuit. A magnetic flux density of is generated. With this configuration, the coil (6
3), when a current is supplied from the drive circuit (83), an electromagnetic force is generated between the coil (1113) and the permanent magnet (81).

At this time, something occurred in the coil (83)! The magnetic force is transmitted to the casing (88) fixed to the vehicle body (0) via the coil support (f14) and acts on the vehicle body (4).
What is the electromagnetic force generated in the permanent magnet (81)?

the restoring force of the elastic body (85) that supports the yoke (62);
These mechanical models, which balance the sum of the inertial forces of the yoke (82) and the permanent magnet (81), are shown in FIG.

In Fig. 4, (9) represents the yoke (62) and the permanent magnet (6).
1), the mass of which is m and L, and the spring constant of the elastic body (65) is 4. U is the electromagnetic force acting between the coil (63) and the permanent magnet (61) in Fig. 3, where the equation of motion of the movable mass object (9) is md"xa ++i xi =
Us i nωt-...(1), and the car body (4
) is the force T that acts as a damping force.

T= U sin (1) t −k 1Lxa
・”...(2).

here.

xdDisplacement U of two movable mass objects (9): 7Driving force ω of actuator (6): Drive angular frequency of actuator (8) (same as the drive angular frequency of the engine) Equations (1) and (2) above By transforming and rearranging, the relationship between the electromagnetic force generated by the actuator (8), that is, the driving force U, and the force T acting on the vehicle body (0) becomes the following equation (3).

T/U= l l-1/(l -(ω/ωn) 2't
l...(3) Here, ωn: Natural angular frequency of actuator (8) (
, 7 So r) tl ``Ding'' This equation (3) is expressed as IT/U with the frequency ratio ω/ωn as the horizontal axis.
The characteristic curve in FIG. 5 is a plot of l, that is, the ratio of the force T acting on the vehicle body (4) to the driving force U generated by the actuator (6), on the vertical axis.

In this characteristic curve, when the natural angular frequency ωn of the actuator (6) is set lower than the drive angular frequency ω, the damping force is transmitted to the vehicle body (4) due to the resonance effect of the vibration system of the actuator (6). T becomes larger than the driving force U. This tendency becomes more pronounced as ω approaches ωn.

For example, as shown by the dashed line, ω/ω
If we set the ratio of n to 1.4, TI'U will be approximately 2,
The damping force T is approximately twice as large as the driving force U.

The present invention makes effective use of these characteristics.

Here, the drive angular frequency ω of the vibration system of the actuator (8) is the same as the angular frequency of the engine that is the vibration source.

The drive angular frequency ω of the actuator (6), that is, the engine frequency, is lowest when idling (ω = ωO), and during this idling, the engine frequency and the natural frequency ω0 of the vehicle body (4) match. Therefore, if we set ωO/ωn > 1, then ω/ωn > 1 for all ω (ω>ωO).
1 is satisfied, and a damping force larger than the driving force U can be obtained.

Here, if ω/ωn is too close to 1, there is a risk that the drive phase of the actuator (8) may reverse and become unstable, so it is preferable to use ω/ωn > 1°3.

On the other hand, when ω/ωn>1.7, I T/U l becomes 1.
3 or less, and the effect of amplifying the driving force U is reduced.

Therefore, as shown by diagonal lines in FIG. 5, the preferred driving range is ω/ωn=1·3 to l·7. Therefore, for example, the natural frequency ωO of the vehicle body (4) is 25H.
z, the minimum value of ω/ωn, ωO/ωn, is set to 1
If the actuator (6) is set to 3 and the operation of the actuator (6) is stopped in the drive angular frequency ω where ω/ωn > 1 and 7, that is, the engine angular frequency, the actuator (6) will be It can be operated effectively within a preferred driving range. In reality, the target of vibration control is the vehicle body (4
) is a resonance state in which the natural angular frequency ωO of In the region of the engine angular frequency ω, the vibration of the vehicle body (4) is small, so there is little need for vibration damping, so the operation of the 7-cut unit (8) is stopped in the region of ω/ωn>1.7. There is no problem.

The present invention has the above-described configuration, detects vibrations of the engine (1) or vibrations acting from the engine (1) on the vehicle body (4), and drives the actuator (6) based on the detection. By driving the vehicle, vibration damping force T is applied to the vehicle body (0) so as to cancel out the vibrations, thereby reducing vibrations of the vehicle body (0) and improving riding comfort and comfort.

In particular, the natural angular frequency ωn of the above vibration system is expressed as
) is set lower than the natural angular frequency ω of the actuator (8), and a specific relationship is established in which the damping force T generated by the driving force U of the actuator (8) is amplified with respect to the driving force U of the actuator (ill), Since this specific relationship was utilized for vibration control, due to the amplifying characteristic described above, it was possible to generate a sufficiently large damping force T even if the current supplied to the actuator (8) that generates the driving force U is small. I can do it.

Therefore, the current supplied to the actuator (8) can be reduced, and the actuator (6) including the drive circuit (83) can be made small in capacity.

Note that the vibration sensor (7) may be configured to detect vibrations at the vehicle body (0), or may be configured to detect vibrations at the vehicle body (0).
As for 8), it is also possible to use pneumatic and hydraulic actuators in addition to linear actuators.

C Effects of the Invention J As explained above, according to the present invention, engine vibration or vibration acting from the engine on the vehicle body is detected, the actuator is driven by the detection, and the actuator is driven to cancel the vibration. Since the structure is designed to apply vibration damping force to the vehicle body, vibrations in the vehicle body are reduced and ride quality and comfort are improved.

In particular, since vibration control uses a specific relationship in which the damping force generated by the driving force of the actuator is amplified with respect to the driving force of the actuator, even if the current supplied to the actuator is small, the vibration damping force generated by the driving force of the actuator is amplified. A large damping force can be generated by amplification, and the actuator can be made smaller.

[Brief explanation of drawings]

Fig. 1 is a block diagram of a vibration control device showing an embodiment of the present invention, Fig. 2 is a block diagram of a control section, Fig. 3 is a sectional view showing an example of an actuator, and Fig. 4 is a dynamic model of the actuator. Figure 5 shows the frequency ratio ω/ωn and IT/Ul
FIG. 6 is a configuration diagram showing the vibration generation mechanism of the vehicle. In the figure, (1) is the engine, (4) is the vehicle body, and (6)
is an actuator, (7) is a vibration sensor, (8) is a control unit, (9) is a movable mass object, (81), (8
3) is a damping drive unit (permanent magnet and coil), and (85) is an elastic body. Note that the same reference numerals in each figure indicate the same or corresponding parts. Agent Patent Attorney Masuo Oiwa Fig. 1 6: Actuator 8: Control part Fig. 4 Fig. 15 Frequency ratio - ωn end 60 Procedural amendment (spontaneous) 1. Indication of case Japanese Patent Application No. 1988-050155 2.
Title of invention Vehicle vibration control device 3 Name of person making the amendment Name (601) Mitsubishi Electric Corporation Representative Hitoshi Katayama 4, Agent 5 Column of “Detailed description of the invention” in the specification to be amended . 6. Contents of amendment (1) The description is amended as follows.

Claims (1)

[Claims] (1) A vibration sensor that detects vibrations of the engine or the vehicle body, a movable mass object attached to the vehicle body via an elastic body, and a vibration sensor connected between the movable mass object and the vehicle body to receive a detection signal from the vibration sensor. an actuator having a vibration damping drive section that applies a damping force to the vehicle body based on the vibration damping force, and a control section that drives the actuator based on a detection signal from the vibration sensor, and the movable mass object of the actuator and the elastic body. A vibration control device for a vehicle, wherein the natural frequency of the vibration system is set lower than the natural frequency of the vehicle body.