JPH1089416A - Control signal generator for active vibration control device for automobile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily obtain signals for control synchronized with engine speed to control exciting force generating means for an active vibration control device. SOLUTION: For a rotation member 16 rotating at a rotation speed corresponding to an engine speed, a measuring plane 40 the distance L from the datum fixed on the engine 12-side varies continuously responding rotation angle of the rotation member 16 is provided. And by measuring the distance between the measuring plane 40 and the datum, a gap detecting means 44 outputting a signal corresponding to the distance between the opposing faces if realized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an active vibration isolator which applies a vibration force to a member to be damped of an automobile so as to actively reduce vibration in the member to be damped. The present invention relates to a control signal generation device in an active vibration isolator for a vehicle for providing a control signal.

[0002]

2. Description of the Related Art In recent years, as one means for achieving a high demand for vibration isolation performance, Japanese Patent Application Laid-Open No. 64-83742 has been disclosed.
As disclosed in Japanese Unexamined Patent Application Publication No. Hei. 3-219139 and the like, a driving force generating means such as an electromagnetic driving means and a piezo element is provided to directly or indirectly apply an exciting force to a vibration damping target member. There has been proposed an active-type vibration damping device that actively reduces the vibration of a member to be damped. The application of such an active vibration isolator to an automobile vibration isolator is being studied by, for example, additionally mounting it on a vehicle body or using it as an automobile engine mount. .

[0003] In such an active vibration isolator, as described in the above-mentioned publications, the excitation force generating means is controlled by an LMS algorithm (least square method) using an adaptive digital filter. However, in order to obtain an effective anti-vibration effect, as a reference signal or a reference signal which is a basis when executing the algorithm, the characteristics of the vibration for the purpose of anti-vibration in the member to be damped are used. It is important to extract highly correlated information. For example, when applied to an automobile vibration isolator, the main cause of vehicle body vibration such as idling vibration and muffled noise is due to the explosion or rotation of the engine, so a signal synchronized with the rotation of the engine is extracted as a reference signal. Thus, it is advantageously used as one of the control signals for the excitation force generating means. Also, in this case, the vibration waveform, and thus the waveform of the exciting force exerted on the member to be damped, is substantially sinusoidal, which is effective in damping, and the processing for control is easy.
Generally, the control signal is extracted as a sine waveform or the like.

However, conventionally, in order to obtain a control signal such as a sine waveform synchronized with the rotation of the engine, a method disclosed in Japanese Unexamined Patent Application Publication No.
As described in Japanese Unexamined Patent Publication No. 72561/1995, a first rotation angle sensor for detecting the rotation angle of the engine and a second rotation angle sensor for detecting the reference position of the crank angle of the engine are used. The output value of the second rotation angle sensor had to be digitally processed. Therefore, in addition to the necessity of two sensors, complicated digital processing is required, and there has been a problem that the device structure and the signal processing system are inevitably complicated and costly.

[0005]

The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to provide a control signal in an active vibration isolator for an automobile, which is used to control the rotation of an engine. It is an object of the present invention to provide a control signal generation device which can easily obtain a signal such as a sine waveform synchronized with the above with a simple device structure and a signal processing system.

[0006]

In order to solve such a problem, a feature of the invention according to claim 1 is that an exciting force generating means is provided to apply an exciting force to a member to be damped of an automobile. For an active vibration isolator that actively reduces vibration in the target member for vibration control, the control means for controlling the exciting force generating means has a high correlation with the vibration of the target member for vibration control. In a control signal generation device for an active vibration isolator for a vehicle that provides a signal, a rotation member that is rotated at a rotation speed corresponding to the engine rotation speed of the vehicle is provided, and the rotation member is positioned on the engine side of the vehicle in the rotation member. The opposite surface to the fixed reference point is a measurement surface in which the distance between the opposite surface to the reference point changes continuously according to the rotation angle of the rotating member about the rotation center line, while the reference points And measurement surface Between opposing surfaces a distance continuously measured,
There is provided a gap detecting means for outputting a signal corresponding to the distance between the facing surfaces and providing the control signal.

In the control signal generating device having the structure according to the first aspect of the present invention, the signal corresponding to the change in the distance between the facing surface of the measurement surface and the reference point when the rotating member rotates, In other words, a signal corresponding to a change in the circumferential shape of the measurement surface around the rotation center line is directly output as a control signal by the gap detection means.

Therefore, by appropriately setting the shape of the measurement surface in the circumferential direction around the rotation center line, a signal having a high correlation with the rotation angle of the rotating member and hence the rotation angle of the engine is transmitted to the measurement surface and the reference surface. It can be obtained directly and easily with a very simple device structure consisting of a single detecting means that only measures the distance between the opposing surfaces of points, and does not require complicated digital processing, etc. The nature is also exhibited.

As the gap detecting means, a magnetic sensor using a Hall element or a sensor utilizing a magnescale can be used. In particular, in the present invention, an eddy current sensor, a capacitance type proximity sensor, A semiconductor magnetoresistive element sensor or the like can be more suitably adopted, whereby the structure of the gap detecting means can be simplified and the cost can be reduced more advantageously.

[0010] The invention described in claim 2 is the same as the claim 1.
In the control signal generation device according to the invention, when the rotation member is rotated around a rotation center line, a change in a distance between the measurement surface and the opposing surface between the reference point becomes a substantially sine waveform. As described above, the shape of the measurement surface is set, and the gap detection means outputs an electric signal of a magnitude linearly corresponding to the distance between the measurement surface and the opposing surface of the reference point. Is the feature.

In the control signal generating apparatus having the structure according to the second aspect of the present invention, the control signal can be converted into a signal which is easy to control in vibration suppression and processing without performing complicated digital processing or the like. It can be directly extracted as a waveform. The ratio of the frequency of the sine wave to the engine speed can be arbitrarily set by appropriately designing the shape of the measurement surface while considering the ratio of the rotation speed of the rotating member to the engine speed. is there.
Note that the gap detecting means includes a sensor as described above,
It may include a correction circuit that corrects the output of the sensor and outputs an electric signal of a magnitude linearly corresponding to the distance between the measurement surface and the reference surface facing each other.

Further, the invention described in claim 3 is the first invention.
Or the control signal generation device according to the invention described in 2, wherein the ratio of the number of rotations of the rotating member per unit time: Na to the number of engine rotations per unit time of the vehicle: Nb: Na / Nb is: It is a positive integer or a reciprocal of a positive integer.

In the control signal generation device having the structure according to the third aspect of the invention, a control signal synchronized with the engine rotation can be obtained very easily.

The invention described in claim 4 is the first invention.
In the control signal generating device according to any one of the above-described aspects, the rotating member is a power transmitting member that is mounted on a rotating shaft that is driven by an engine of the vehicle and transmits a rotating force to another member. That is the feature.

In the control signal generating device having the structure according to the fourth aspect of the present invention, a rotating member is constituted by a power transmitting member such as a pulley or a gear, and a part of the power transmitting member is used. Since the measurement surface is formed, a special rotating member is unnecessary, and the structure can be simplified.

The invention described in claim 5 is the first invention.
5. The control signal generation device according to any one of claims 4 to 4, wherein the reference point faces the measurement surface provided on the rotating member in a direction orthogonal to a rotation center line of the rotating member. It is characterized by being positioned.

In the control signal generating device having the structure according to the fifth aspect of the present invention, the measuring surface of the rotating member is formed as a cylindrical surface on the outer peripheral surface or the inner peripheral surface of the rotating member. Therefore, there is an advantage that the formation is easy.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, in order to clarify the present invention more specifically, embodiments of the present invention will be described in detail with reference to the drawings.

First, FIG. 1 and FIG. 2 show a control signal generation device 10 as one embodiment of the present invention.
In these figures, reference numeral 12 denotes an engine body constituting a power unit of an automobile, which is not explicitly shown in the drawings, but is constituted by a predetermined internal combustion engine. A pulley 16 for transmitting a rotational driving force generated by the internal combustion engine to a camshaft, an alternator, and the like is mounted on a crankshaft 14 of the internal combustion engine in the engine body 12. And in this embodiment,
By using the pulley 16 as a rotating member, a control signal synchronized with the engine speed is extracted.

More specifically, the pulley 16 is provided with a damper mechanism 20 with respect to a pulley body 18 constituting a central portion thereof.
Is mounted in an extrapolated state. The pulley body 18 includes a small-diameter cylindrical boss portion 22 and a large-diameter cylindrical shape cylindrical portion 24 that are positioned on the same axis at a predetermined radial distance from each other. The portion 24 is integrally connected by four plate-shaped connecting portions 26 extending across the radially opposed surfaces of the members 22 and 24. On the other hand, the damper mechanism 20 includes a substantially thick cylindrical damper mass 28 as a whole, and a thin cylindrical metal sleeve 30 disposed on the same axis at a predetermined distance radially inward thereof. It is constituted by an integrally vulcanized molded product having a structure elastically connected by a thin cylindrical rubber elastic body 32 interposed between the radially opposed surfaces. And the metal sleeve 30
Is press-fitted and fixed to the cylindrical portion 24 of the pulley body 18, so that the damper mechanism 20 is integrally attached to the pulley body 18.

The boss portion 22 of the pulley body 18
A key groove 34 is provided on an inner peripheral surface of the crankshaft 14. A boss 22 is externally fixed to the axial end of the crankshaft 14 so as to be relatively non-rotatable by a key 35 fitted in the key groove 34. ing. Further, a large number of V-grooves 36 are formed on the outer peripheral surface of the damper mass 28, and a V-belt having a cross-sectional shape corresponding to these V-grooves 36 can be wound.

The pulley 16 is integrally rotated with the crankshaft 14 about a rotation center line 37 of the crankshaft 14 and is connected to the camshaft via a V-belt wound around the outer peripheral surface. And the like, and functions as a power transmission member for transmitting a rotational driving force to a subsequent member, such as a rubber damper. The mechanism 20 can function as an effective vibration absorber (sub-vibration system).

On the other hand, the boss 22 of the pulley body 18
Is located on one side in the axial direction by a predetermined amount with respect to the cylindrical portion 24 and the damper mechanism 20.
When mounted on the crankshaft 14, one side in the axial direction of the boss portion 22 is positioned so as to project toward the engine body 12.

The outer diameter dimension of the boss portion 22 is continuously changed in the circumferential direction at a distal end portion 38 in the protruding direction from the connecting portion 26. Note that “continuous” refers to a shape having no step portion or the like. In particular, in the present embodiment,
The outer peripheral surface of the distal end portion 38 has an elliptical shape in a cross section perpendicular to the axis.
It is set to 0. That is, the measurement surface 40 of this elliptical cross-sectional shape
Is the center axis of the pulley 16 and thus the crankshaft 14
The center diameter of the rotation center line 37 is the center axis, and its outer diameter is periodically and continuously changed in the circumferential direction with one cycle of 180 ° around the center axis.

On the other hand, the pulley 1
The mounting projection 4 protrudes toward the pulley 16 at a position spaced a predetermined distance from the outer periphery of the crankshaft 14 on which the mounting 6 is mounted.
2, a distance sensor 44 as a gap detecting means is fixedly supported by the mounting protrusion 42. As a result, the distance sensor 44
6, is located at a predetermined distance outside of the boss portion 22 in the direction perpendicular to the axis, and faces a measurement surface 40 provided at the boss portion 22 at a predetermined distance in a direction perpendicular to the measurement surface 40. It has been impatient.

A distance L between the measurement surface 40 and the mounting point of the distance sensor 44 on the engine body 12 is measured by the distance sensor 44, and the distance L is measured according to the distance L. A signal is output. As is apparent from this, in the present embodiment, the mounting point of the distance sensor 44 on the engine body 12 is determined by the rotation center line 37 of the pulley 16 as a rotating member.
Is a reference point whose position relative to is fixed.

Here, the distance sensor 44 may be any as long as it can output a signal corresponding to the magnitude of the distance L between opposing surfaces, but in this specific embodiment, in particular, the distance L between opposing surfaces is L. That can continuously output an electric signal having a magnitude linearly corresponding to the magnitude of the signal or a small time interval. In addition, as such a distance sensor 44, specifically, for example, an eddy current sensor, a capacitance type proximity sensor, a semiconductor magnetoresistive element sensor, or the like is preferably employed because of its simple structure.

In the control signal generator 10 having the above-described structure, the internal combustion engine of the engine body 12 is operated, and the pulley 16 and the crankshaft 14 are simultaneously operated.
Is rotated, is measured by the distance sensor 44,
The distance L between the opposing surfaces of the measurement surface 40 of the boss portion 22 and the distance sensor 44 is continuously changed according to the rotation angle of the boss portion 22 of the pulley 16 and thus of the crankshaft 14. Since the measurement signal from the distance sensor 44 is changed in accordance with the change in the distance L between the facing surfaces, the measurement signal from the distance sensor 44 is a signal synchronized with the rotation angle of the crankshaft 14. is there.

Also, in this embodiment, since the measuring surface 40 has an elliptical cross section, the distance sensor 44 outputs a waveform signal having one cycle corresponding to a half rotation of the crankshaft 14. Will be done. Therefore, for example, as shown in a model diagram in FIG. 3, by setting the outer peripheral surface shape of the measurement surface 40 in a section perpendicular to the axis in accordance with the following (Equation 1), the output signal of the distance sensor 44 becomes As shown in FIG. 4, it is possible to obtain a sine waveform electric signal having a frequency twice the rotation frequency of the crankshaft 14.

L (θ) = ((A−B) / 2) · cos2θ + ((A + B) / 2) (1) where l (θ) is the distance from the center point to the outer peripheral surface, A is the length of the long axis, B is the length of the short axis, and θ is the rotation angle around the center point.

The output signal obtained in this manner is applied to a vibration force in a vibration isolator as described in, for example, the above-mentioned Japanese Patent Application Laid-Open Nos. 64-83742 and 3-219139. It is used as a control signal of the generating means, and is used as a reference signal when the LMS algorithm (least squares method) using an adaptive digital filter is input to the control device of the exciting force generating means, for example. Will be done. Here, the output signal of the distance sensor 44 obtained as described above has a sine waveform synchronized with the secondary rotation of the crankshaft 14, that is, the secondary rotation of the engine. It can be input to the control device of the generating means and adopted as a reference signal.

In addition, since the output signal of the distance sensor 44 is completely synchronized with the rotation angle of the crankshaft 14 of the engine body 12, it has a very high correlation with the characteristics of the vibration for the purpose of preventing vibration. Therefore, by employing this output signal as the reference signal, it is possible to stably obtain an extremely excellent vibration damping effect.

In particular, the control signal generator 10 as described above
According to this, the signal for controlling the sine waveform corresponding to the vibration to be damped can be directly and easily obtained by the single distance sensor 44 without requiring any special numerical operation processing or the like. That is, simplification of the structure of the control signal generation device of the excitation force generation means and cost reduction can be advantageously achieved.

Although the specific embodiments of the present invention have been described in detail above, the present invention is not construed as being limited by the specific descriptions of the embodiments.

For example, in the above-described embodiment, a specific example of obtaining a control signal of a sine waveform synchronized with the secondary rotation of the crankshaft 14, that is, the secondary rotation of the engine has been described. By appropriately setting the shape, a control signal having a waveform synchronized with an arbitrary rotation speed of the crankshaft 14 can be extracted. Further, in the above embodiment, the pulley 16 as a rotating member is used.
Was mounted on the crankshaft 14 so that it could be rotated at the same speed as the engine speed.
A pulley 16 is attached to an appropriate rotating shaft driven by the crankshaft 14 at a rotation speed different from the engine rotation speed.
It is also possible to attach a pulley 1 in that case.
6: ratio of Na: engine speed: Nb: m = N
The shape of the measurement surface 40 is appropriately set in consideration of the value of a / Nb.

Specifically, for example, by adopting the shape of the measurement surface 40 expressed by the following (Equation 2), it is possible to advantageously extract a sine waveform control signal synchronized with the nth order of engine rotation. Becomes

L (θ) = ((ab) / 2) · cos ((n / m) θ) + ((a + b) / 2) (Expression 2) where l (θ) is the center The distance from the point to the outer peripheral surface (measurement surface), a is the distance from the center point to the point on the outer peripheral surface furthest from the center point, b is the distance from the center point to the point on the outer peripheral surface closest to the center point, n
Is the engine rotation order component corresponding to the control signal, m is the ratio of the rotation speed of the rotating member to the engine rotation speed, and θ is the rotation angle around the center point.

That is, in the above (Equation 2), for example, if n / m = 1 and the shape of the measurement surface 40 along the axis is determined, the measurement surface 40 becomes as shown in FIG.
With the distance sensor 44, a control signal of a sine waveform synchronized with the engine rotation primary can be taken out, and if the shape of the measurement surface 40 along the axis is determined as n / m = 3, it will be shown in FIG. The measurement surface 40 is as described above, and the distance sensor 44 can extract a control signal of a sine waveform synchronized with the engine rotation tertiary.

In the above-described embodiment, the measurement surface 40 is constituted by the outer peripheral surface of the boss portion 22 of the pulley 16, but the measurement surface positioned to face the distance sensor 40 is:
At an appropriate portion of the pulley 16, the pulley 16 may be constituted by an inner peripheral surface, an axial end surface, or the like. Specifically, for example, as shown in FIG. 7, the height of the distal end portion 38 of the boss portion 22 in the axial direction is continuously changed in the circumferential direction, so that the distal end portion 38 The end surface in the axial direction can be used as the measurement surface 46. In addition,
When such a measurement surface 46 is employed, a distance sensor 44 fixed on a reference point of the engine body 12
7, the distance between the measurement surface 46 and the reference surface in the axial direction is measured by the distance sensor 44. And
In particular, in FIG. 7, a measurement surface 46 having a shape in which the axial end surface of the distal end portion 38 is cut obliquely with respect to the rotation center line 37 is employed. And an output signal having a sine waveform synchronized with the output signal is obtained.

Further, in the above-described embodiment, the measuring surface 40 is formed by using a part of the pulley 16 mounted on the rotating shaft. However, the measuring surface can be formed on a rotating member other than the pulley. Yes, and of course it is also possible to mount a special rotating member to form the measuring surface.

It is not always necessary to set the measurement surface so that the change in the distance between the reference surface and the reference surface according to the rotation angle of the rotating member indicates a sine waveform. Can be set appropriately in consideration of the characteristics of the above. For example, when the gap detection means has a non-linear output characteristic with respect to the measurement distance, taking into account the output characteristic, a waveform of the effective control signal can be obtained so as to obtain an effective control signal waveform. It is desirable to set the shape.

In addition, the control signal generating device having the structure according to the present invention can be applied to various types of automobile anti-vibration devices provided with exciting force generating means. It can exhibit an excellent effect of suppressing vibration caused by engine vibration.

In addition, although not enumerated one by one, the present invention
Based on the knowledge of those skilled in the art, various changes, modifications, improvements, and the like can be made, and unless such embodiments depart from the spirit of the present invention.
Both are included in the scope of the present invention,
Of course.

[0044]

As is apparent from the above description, in the control signal generating device for the active vibration isolator for a vehicle having the structure according to the present invention, the reference point measured by the gap detecting means and the measurement surface are measured. Since the distance between the facing surfaces is continuously changed in accordance with the engine rotation, the output signal of the gap detecting means has a high correlation with the characteristics of the vibration for the purpose of vibration isolation completely synchronized with the engine rotation. Therefore, by using the output signal of the gap detecting means as a control signal of the exciting force generating means, it is possible to stably obtain an extremely excellent vibration damping effect. It becomes.

Further, according to the control signal generating apparatus, the control signal having the waveform corresponding to the vibration to be damped can be obtained by the single gap detecting means without requiring any special numerical processing or the like. Since it can be obtained directly and easily, simplification of the structure and cost reduction can be advantageously achieved.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a control signal generation device as one embodiment of the present invention.

FIG. 2 is a left side view in FIG.

FIG. 3 is an explanatory diagram schematically showing a main part of the control signal generation device shown in FIG. 1;

FIG. 4 is a graph showing output characteristics of a distance sensor in the control signal generation device shown in FIG.

FIG. 5 is an explanatory front view schematically showing another specific example of a measurement surface that can be employed in the control generation device shown in FIG. 1;

6 is an explanatory front view schematically showing another specific example of a measurement surface that can be employed in the control generation device shown in FIG. 1. FIG.

FIG. 7 is an explanatory side view schematically illustrating another specific example of a measurement surface that can be employed in the control generation device illustrated in FIG. 1;

[Explanation of symbols]

 Reference Signs List 10 control signal generation device 12 engine body 14 crankshaft 16 pulley 37 rotation center line 40, 46 measuring surface 44 distance sensor

Claims (5)

[Claims] 1. An active vibration isolator comprising a vibrating force generating means for applying a vibrating force to a vibration damping member of an automobile to thereby actively reduce vibration in the vibration damping member. In a control signal generation device for an active vibration isolator for a vehicle for providing a control signal having a high correlation with the vibration of the vibration suppression target member for controlling the excitation force generating means, A rotating member that is rotated at a corresponding number of revolutions is provided, and a surface of the rotating member facing a reference point set to be fixed on the engine side of the vehicle according to a rotation angle around the rotation center line of the rotating member. While the distance between the opposing surfaces with the reference point is continuously changed, the distance between the opposing surfaces of the reference point and the measurement surface is continuously measured, and a signal corresponding to the distance between the opposing surfaces is obtained. Output Control signal generating device in a motor vehicle for an active vibration insulator which is characterized in that a gap detection means for providing a use signal. 2. The shape of the measurement surface such that a change in the distance between the measurement surface and the reference surface when the rotating member is rotated about a rotation center line has a substantially sinusoidal waveform. Is set, and the gap detecting means is:
2. The control signal generating apparatus according to claim 1, wherein an electric signal having a magnitude linearly corresponding to a distance between the measurement surface and the opposing surface of the reference point is output. . 3. The ratio of the number of revolutions of the rotating member per unit time: Na to the number of engine revolutions per unit time of the vehicle: Nb: The value of Na / Nb is a positive integer or a reciprocal of a positive integer. A control signal generation device for an active vibration isolator for a vehicle according to claim 1 or 2. 4. The vehicle according to claim 1, wherein the rotating member is a power transmitting member mounted on a rotating shaft driven by an engine of the vehicle and transmitting a rotating force to another member. A control signal generation device in an active vibration isolator. 5. The reference point according to claim 1, wherein the reference point is opposed to the measurement surface provided on the rotating member in a direction orthogonal to a rotation center line of the rotating member. 3. A control signal generation device in the active vibration isolator for a vehicle according to claim 1.