JP2500017B2 - Vibration generator - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration generator using an electric motor.

[0002]

2. Description of the Related Art Conventionally, as a vibration generator using an induction motor, one disclosed in Japanese Patent Publication No. 36-16693 is known. In this system, two induction motors are provided on a single support, the two motors are rotated in opposite directions, and the vibration periodical force acts by simply increasing the rotation frequency of the induction motor. It generates vibration.

[0003]

FIG. 1 is a schematic view of a vibration generator having such two electric motors rotating in opposite directions. The vibration generating system of the vibration generating device shown in FIG. 1 is schematically shown in FIG. FIG.
In the model shown in Fig. 3, given set values such as the natural frequency of translational mode, the natural frequency of rotational mode, the amplitude of the excited body, the size of the unbalanced weight, etc. Enter, simulate,
The torque required for the electric motor was calculated. FIG. 4 shows the results.

In FIG. 4, a curve A indicating the translation mode required torque shows the minimum required torque of the electric motor required to perform only the translation mode. Rotation mode required torque B
Indicates the minimum required torque required to perform the rotation mode. The present inventor, from the simulation calculation result,
In the model of FIG. 3, in order to stably oscillate the body to be excited in the translational mode, from the graph of FIG. 4, the rotation frequency of the motor is set to Ω _A or higher, and the output torque at that rotation frequency is T. We have found that it is sufficient to use an electric motor of _A or higher.

The present invention has been discovered based on the simulation calculation results of the present inventor, and it is an object of the present invention to provide a vibration generator that vibrates a body to be excited only in a translation mode by an extremely simple method. To aim.

[0006]

A vibration generator according to the present invention for achieving the above object comprises a first rotary vibrating body having an unbalanced weight and a rotary shaft for fixing the unbalanced weight. A second rotary vibrating body that has an unbalanced weight and a rotation shaft that fixes the unbalanced weight, and that rotates at the same rotational speed in a direction opposite to the rotation direction of the first rotational vibrating body; A first vibrating body to which the first vibrating body and the second vibrating body are attached, and an elastic body that elastically couples the vibrating body to a fixed portion. The natural frequency of the rotation mode and the natural frequency of the translational mode of the whole system including the excited body and the elastic body satisfy the following equation,

[0007]

[Equation 2] When the rotational frequency and the required torque are the same in the rotation mode and the translation mode of the entire system, the rotation frequency is Ω.
_A, when the required torque and T _A, wherein the required torque of the first and second rotating oscillator is not less than T _A.

[0008]

According to the present invention, the weight of the object to be excited, the spring constant of the elastic body, the natural frequency of the translation mode, the natural frequency of the rotation mode, etc. are input, and the vibration generator having the required specifications by simulation is input. Can be easily designed and manufactured.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. The vibration generator according to the embodiment of the present invention is a device that satisfies the following conditions. This condition is a result obtained by computer simulation calculation. In the vibration model shown in FIG. 5, 7 is a first rotary vibration system, 8 is a second rotary vibration system, 3 is an object to be excited, 9 and 10 are elastic bodies, and 12 is a fixed part.

Here, T _L and T _R : required torques for rotating the shafts 1 and 2 X _L and X _R : displacement of the body 3 to be excited (x direction) Z _L and Z _R : shaft 1, 2 the displacement (x-direction) F _L, F _R: When excitation force generated by rotating the shaft 1, 2 (x-direction),

[0011]

(Equation 3) The vibration equation of the body to be excited is expressed by (3) and (4).

[0012]

[Equation 4] Required torque T _L to maintain or accelerated imbalance governor weight 5, 6, T _R is represented by the following equation.

[0013]

(Equation 5) Here, assuming that the resistances of the equations (5) and (6) can be ignored, the required minimum torque T is

[0014]

From ≧ 0 ≧ 0,

[0015]

## EQU00007 ## T = -mr ( _R sin .phi.-mr _L sin .psi.
(7) Change the variables in equations (3) and (4).

[0016]

## EQU8 ## Substituting = X _R -X _L X = X _R + X _L ,

[0017]

[Equation 9] By transforming (8) and (9),

[0018]

[Equation 10] However,

[0019]

[Equation 11]

[0020]

(Equation 12) Solution of (8) ', (9)'

[0021]

(Equation 13)

[0022]

[Equation 14] By the way, Z _R and Z _L are represented as shown below.

[0023]

(Equation 15) Substituting (16) and (17) into (20) and (21) and differentiating twice
Substituting into (7), α = 0 (no phase difference; translation mode required torque) and α = π (phase difference π: rotation mode required torque) are substituted into equation (7). When α = 0

[0024]

## EQU16 ## T (0) =-mr ( _R + _L ) sinωt ...
(7) 'When α = π

[0025]

## EQU17 ## T (π) =-mr {_Rsinωt + mr_Lsin
(Ωt + π)} (8) 'At this time, | T (0) | (translation mode required torque), |
T (π) | (rotation mode required torque)
The rotation frequency ω of shafts 1 and 2 can be calculated by simulation.
By changing | T (0) | and | T (π) | at each value of ω
When max is calculated, a curve as shown in FIG. 6 is obtained, and | T
Intersection Ω of (0) | and | T (π) |_A , T _A Is found.

Ω_A At lower rotational frequencies, lower torque
It vibrates in the rotation mode, but Ω_AAbove the rotational frequency of
Has a lower torque in the translation mode,
Vibration is obtained. Rotational vibration when increasing the rotational frequency
Number is 0-Ω_A Up to the torque curve of the rotation mode.
Luk T_A Need to raise. This is the vibration system
Luk is T _A If it is smaller, the rotation frequency is Ω_A Raised above
Because it is not possible. To get the translation mode, the rotational frequency
Ω_A It is necessary to set the above frequency, and for that purpose
Is the torque of the motor is T_A It is necessary to have the above performance.

[0027]

As described above, according to the vibration generator of the present invention, there is an effect that it is possible to surely obtain the translational mode vibration which has not been obtained due to the insufficient torque of the electric motor. Further, there is an effect that the translation mode can be easily obtained by using the vibration system of the minimum required torque in which the required torque of the vibration device is calculated by simulation.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a vibration system according to an embodiment of the present invention.

FIG. 2 is a schematic diagram showing a first vibration system and a second vibration system of the present invention.

FIG. 3 is a schematic view showing a vibration generator according to an embodiment of the present invention.

FIG. 4 is a view for explaining the operation of the embodiment of the present invention, and is a diagram showing the relationship between the rotational frequency of the motor and the required torque of the motor.

FIG. 5 is a schematic diagram showing a model of an example of the present invention.

FIG. 6 is a characteristic diagram showing a rotation mode and a translation mode.

Claims (1)

(57) [Claims] 1. A first rotating vibrating body having an unbalanced weight and a rotating shaft for fixing the unbalanced weight, an unbalanced weight and a rotating shaft for fixing the unbalanced weight. A second rotational vibrating body that rotates at the same rotational speed in a direction opposite to the rotational direction of the first rotational vibrating body, and a vibrating body to which the first rotational vibrating body and the second rotational vibrating body are attached And an elastic body that elastically couples the excited body to the fixed portion, and the natural frequency of the rotation mode of the entire system including the first and second rotational vibrating bodies, the excited body, and the elastic body. And the natural frequency of the translation mode satisfy the following equation, and When the required torques of the rotation mode and the translational mode of the entire system including the first and second rotary oscillators, the body to be excited, and the elastic body match, the rotational frequency is Ω _A and the required torque is T _{If A} , the required torque of the first and second rotary oscillators is T _A or more.