JPH10292844A - Vibration support bracket - Google Patents

Abstract

(57) [Problem] To provide a support bracket for a vibration generator, which is capable of achieving both a higher level of vibration isolation and vibration suppression over a wide frequency range. SOLUTION: The support bracket of the vibration generator is made of a plate spring-like member 8 in which the plate-like piezoelectric conversion element 2 is closely arranged in a proper position.
And a control means 4 for controlling the amount of distortion of the piezoelectric conversion element. According to the amount of deformation of the leaf spring-like member, internal stress is generated in the piezoelectric conversion element in a direction of restraining or promoting the same. It is assumed that Thus, by changing the voltage applied to the piezoelectric conversion element, the apparent spring constant of the leaf spring-like member to which the piezoelectric conversion element is attached can be freely changed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bracket for supporting a vibration generator, and more particularly to a bracket suitable for supporting a power transmission device for an automobile such as a differential gear.

[0002]

2. Description of the Related Art Conventionally, an elastic member such as a rubber bush is interposed in a mounting portion of a device, such as a differential device, which generates vibrations to the vehicle body, thereby transmitting the vibration to the vehicle body. Was alleviated.

[0003]

However, according to this conventional method, it is better to have a high compliance of the elastic member in order to enhance the vibration isolation, but on the other hand, a high vibration damping force, that is, a vibration damping property is required. It is necessary to have an appropriate rigidity in order to increase the height, that is, it is difficult to achieve both vibration isolation and vibration damping.

[0004] The present invention has been devised to solve such problems of the prior art, and its main objects are as follows.
An object of the present invention is to provide a support bracket for a vibration generator, which can achieve both higher levels of vibration isolation and vibration suppression over a wide frequency range.

[0005]

In order to achieve such an object, in the present invention, a support bracket for a vibration generator is combined with a leaf spring-like member 8 on which a plate-like piezoelectric transducer 2 is closely arranged in a proper position. And control means 4 for controlling the amount of distortion of the piezoelectric conversion element, and in accordance with the amount of deformation of the leaf spring-like member, internal stress is generated in the piezoelectric conversion element in a direction of restraining or promoting it. It was made. According to this, by changing the voltage applied to the piezoelectric conversion element, it is possible to freely change the apparent spring constant of the leaf spring-shaped member to which the piezoelectric conversion element is attached.

The piezoelectric transducers include PZT (zirconate titanate), PLZT (lanthanum zirconate titanate), and PMN (magnesium niobium lead oxide).
PVDF (polyvinylidene fluoride) and the like are used.

[0007]

Embodiments of the present invention will be described below in detail with reference to the embodiments shown in the accompanying drawings.

FIG. 1 shows a damping panel used in the present invention. The vibration damping panel 1 generates a voltage according to the strain and generates a strain according to the applied voltage. As shown in FIG. 2, a rectangular flat-plate-shaped piezoelectric conversion element made of PZT or the like is used. 2, a pair of copper electrodes 3 provided on both front and back surfaces of the piezoelectric conversion element 2, a control circuit 4 connected to the pair of copper electrodes 3,
It has an epoxy resin coating 5 integrated by thermocompression bonding so as to cover the copper electrode 3 and the control circuit 4. Further, a conductive sheet 6 containing Ni is provided between the piezoelectric transducer 2 and the copper electrode 3, and a polyimide film 7 is provided on both front and back surfaces of the cover 5.

The control circuit 4 is a resonance analog circuit having a frequency characteristic corresponding to a resonance frequency of a differential device described later. More specifically, as shown in FIG. A resistor R is connected in series with L, or a capacitor C is connected in parallel with the resistor R and the coil L connected in series as shown in FIG.

FIG. 5 shows a mounting bracket for a vehicle body of a differential gear to which the present invention is applied. This bracket 8
Is basically made of a flat bar-shaped leaf spring material, and is bent in a substantially trapezoidal shape as shown in FIG. Bolted to The above-described vibration damping panel 1 is attached near the bent portion of the bracket 8.

Next, the operation principle of the device of the present invention will be described.

When bending vibration occurs in the bracket 8 due to the vibration of the differential device 9, the bending direction is periodically directed to the piezoelectric conversion element 2 of the vibration damping panel 1 disposed at an appropriate position of the bracket 8 with the deformation of the bracket 8. Is inverted, and a voltage that changes periodically is input from the piezoelectric conversion element 2 to the control circuit 4 in response to the distortion. Then, when the bracket 8 starts to vibrate at the resonance frequency, the control circuit 4 having the frequency characteristic corresponding to the resonance frequency suppresses the distortion of the piezoelectric transducer 2, that is, the vibration in the direction to suppress the vibration of the bracket 8. A voltage is applied to the piezoelectric conversion element 2 so as to generate a force.

For example, when bending vibration occurs, the bracket 8
When it is bent as shown in FIG. 7, distortion in the extension direction is generated in the vibration damping panel 1. Then, a compressive stress (arrow A) in a direction opposite to this is generated in the piezoelectric conversion element 2 of the vibration damping panel 1. The bracket 8 bends in the opposite direction and the vibration damping panel 1
Is distorted in the compression direction, tensile stress is generated in the piezoelectric conversion element 2 of the vibration damping panel 1. The internal stress generated in the piezoelectric transducer 2 acts as a damping force for suppressing the vibration of the bracket 8, and as a result, the apparent rigidity of the bracket 8 increases.

According to this, since the spring stiffness of the bracket 8 itself can be set to the minimum value capable of supporting the differential device 9, the vibration isolation at normal time can be achieved by supporting the differential device 9 with high compliance. In the resonance mode, a damping force is generated by the internal stress generated in the piezoelectric conversion element 2, so that a high vibration damping property can be obtained.

In the above embodiment, the passive control by the analog circuit 4 built in the vibration damping panel 1 has been described, but this is performed on the opposite side of the vibration damping panel 1 with the bracket 8 interposed therebetween, as shown in FIG. Another piezoelectric transducer 2
a, which is used as a vibration sensor, and as shown in FIG.
To calculate the vibration frequency and vibration amplitude of the bracket 8, and apply a voltage for generating a vibrating force in a direction to cancel the vibration of the bracket 8 from the battery 13 to the piezoelectric conversion element 2 via the amplifier 14. It is also possible to use active control. According to this, the frequency of the voltage applied to the piezoelectric conversion element 2 can be freely adjusted according to the vibration frequency and the vibration amplitude of the bracket 8, so that vibration can be suppressed over a wide range, and it is difficult with the conventional method. It is also possible to cut off low frequency regions. Further, not only the above-described vibration damping action, but also an internal stress in a direction that promotes the bending of the bracket 8 can be generated in the piezoelectric conversion element 2. The apparent dynamic compliance of the bracket 8 can be enhanced by the action of the conversion element 2.

Although the above embodiment has been described with reference to a bracket for a differential, the present invention is not limited to this and can be widely used as a support bracket for a vibration generator.

[0017]

As described above, according to the present invention, the compliance of the bracket for supporting the vibration generating body and the spring rigidity can be realized at a higher level, so that the vibration can be obtained over a wide frequency range. A great effect can be achieved in further improving the cutoff efficiency and the vibration suppression efficiency. In addition, since it is not necessary to adjust the natural frequency to lower the vibration level in the normal range, there is a secondary effect that the increase in the weight and the complexity of the shape are not caused.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view of a vibration damping panel used in the present invention.

FIG. 2 is a sectional view of the vibration damping panel shown in FIG.

FIG. 3 is a conceptual diagram showing a configuration example of a control circuit built in the damping panel shown in FIG.

FIG. 4 is a conceptual diagram showing another configuration example of a control circuit built in the damping panel shown in FIG. 1;

FIG. 5 is a perspective view of a differential gear to which the bracket according to the present invention is applied.

FIG. 6 is a schematic elevation view showing the entire configuration of the present invention.

FIG. 7 is an explanatory view of the operation principle of the vibration damping panel.

FIG. 8 is a schematic elevation view showing another embodiment of the bracket according to the present invention.

FIG. 9 is a block diagram showing another control method of the vibration damping panel.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Vibration suppression panel 2 Piezoelectric conversion element 3 Copper electrode 4 Control circuit 5 Coating body 6 Conductive sheet 7 Polyimide film 8 Bracket 9 Differential device 10 Body 11 Vibration sensor 12 Control circuit 13 Battery 14 Amplifier

Claims (1)

[Claims] 1. A plate spring-like member in which a plate-like piezoelectric conversion element is closely arranged in a proper position, and control means for controlling a distortion amount of the piezoelectric conversion element. A support bracket for a vibration generator, wherein internal stress is generated in the piezoelectric transducer in a direction in which the piezoelectric transducer is restrained or promoted.