JPH1194691A - Exciter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To generate a vibration in rectilinear direction with a simple mechanical constitution by reciprocating a weight in the vertical direction driven by rotation of a cam provided in a rotary shaft. SOLUTION: A base 6 of the exciter is disposed to make the moving direction of a weight 3 vertical to the ground surface. Though a rotary shaft 1 and a cam 2 are rotated when a motor 5 is rotated, the rotary shaft 1 generates no vibration since the rotary shaft 1 is provided in the gravity center of the cam 2, and since the cam 2 is balancing mass. The weight 3 repeats substantially vertical reciprocating motion by rotation of the cam 2 and a linear guide 4. When the weight 3 moves substantially vertically in the upward direction, a force in the direction opposing to the receiving force of the weight 3 is generated in the disposed site of the exciter according to the action and reaction principle, and the installation place receives vertically downward force via the base 6. Vibration in the only vertical direction is generated in the ground by this manner.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exciter for applying vibration to a ground or the like in order to measure physical properties of the ground or the like.

[0002]

2. Description of the Related Art Conventionally, when measuring physical properties such as the allowable bearing capacity of the ground, a system comprising an exciter for applying vibration to the ground and a vibration sensor for detecting the generated vibration has been used. In general, in such a system, in order to detect a Rayleigh wave oscillating in the vertical direction, it is preferable that the exciter is one that excites only in a vertical direction or a linear direction such as a direction perpendicular to the ground surface. Accordingly, a vibration exciter for giving such a linear vibration is disclosed in Japanese Patent Application Laid-Open No. 59-12788.

[0003]

However, the above-described vibration exciter has the following problems. That is, in this exciter, unbalanced weights are attached to a pair of rotating shafts, and these are rotated in opposite directions to generate vibration. However, since a pair of weights is required as described above, the mechanical configuration of the device may be complicated. Also, when the relative position of the two weights was changed, vibrations other than in the linear direction occurred.

[0004] An object of the present invention is to provide a vibration exciter capable of excluding such disadvantages and applying linear vibration with a simple mechanical structure.

[0005]

According to a first aspect of the present invention, there is provided a vibration exciter, comprising: a rotary shaft, a cam provided on the rotary shaft, a weight driven by the cam, And a support for supporting the weight so that reciprocation is possible.

Here, the rotating shaft is a shaft that is rotated by the power of a motor, an engine, or the like. A cam is a mechanical component such as a plate or a cylinder that transmits motion by an edge or a groove formed on the surface. The cam may be integral with or separate from the rotating shaft. The weight may follow the cam directly or indirectly via some component. The support restricts the movement of the weight following the cam in a linear direction. For example, a linear guide,
There is one that supports the weight with a spring or the like. In the linear direction,
There is a vertical direction and a direction perpendicular to the ground surface.

According to a second aspect of the present invention, there is provided the vibration exciter according to the first aspect, wherein the weight of the weight is variable.

Here, the weight may have a structure in which a plurality of weights can be attached and detached, or a weight having a container-like structure in which a certain substance such as liquid or solid can be filled.

According to a third aspect of the present invention, there is provided the vibration exciter according to the first aspect, wherein the cam has a plate shape having a uniform thickness, and a rotation shaft is provided at a center of gravity of the cam.

[0010]

According to the vibration exciter of the first aspect, the cam is also rotated by the rotation of the rotating shaft, and the weight is driven by the cam. Furthermore, if the exciter is installed so that the weight can move in the vertical direction,
The weight reciprocates vertically in the support. When the weight moves vertically upward, a force in the opposite direction to the force applied to the weight is generated at the installation location of the vibration exciter due to the principle of action and reaction. For example, when the exciter is installed on the ground surface, a force acts in a direction to press the ground, and vibration is generated in the ground.

According to the vibration generator of the second aspect, since the vibration force is proportional to the weight of the weight, the vibration force of the vibration generator can be changed by changing the weight of the weight.

According to the third aspect of the present invention, since the cam has a plate shape with a uniform thickness and the rotating shaft is provided at the center of gravity of the cam, the moment generated by the rotation of the cam is canceled.

[0013]

Next, an embodiment of the present invention will be described. FIG. 1 shows an embodiment of the present invention. The exciter shown in FIG. 1 includes a rotating shaft 1, a motor 5, a cam 2 provided on the rotating shaft 1, a weight 3 driven by the cam 2, a linear guide 4 supporting the weight 3, a motor 5, and a linear guide 4. And a base 6 on which is disposed. FIG. 2 is an exploded perspective view of the exciter.

The rotating shaft 1 is rotatably supported by bearings 7 at both ends. The motor 5 has gears built therein, and drives the rotating shaft 1 via these gears. The output of the motor 5 is 1 kW.
The number of rotations can be set arbitrarily from 5 to 50 rotations / second. The motor 5 is mounted on a base 6. The shape of the cam 2 is an elliptic plate having a uniform thickness.
The rotation shaft is provided at the center of gravity of the cam 2. For this reason, the moment generated by the rotation of the cam 2 is canceled, so that the rotating shaft 1 does not receive a force in the direction perpendicular to the shaft or generate vibration. The material of the cam 2 is a hard material obtained by hardening iron.

The linear guide 4 supports the weight 3 by following the cam 2 and moving in a straight line. The linear guide 4 is provided with a ridge, and the protruding portion of the weight 3 fits into the ridge. This allows the weight to move in a linear direction.

The weight 3 comprises a plurality of weights 31 and a base 32, and a desired weight can be obtained by combining the weights 31. The base 32 is fitted on the linear guide 4 so as to be slidable. Weight 3
The screw structure is used for attaching and detaching the base 1 and the base 32. As described above, by increasing or decreasing the weight of the weight 3, the exciting force of the exciter can be changed. It is also easy to carry.

The base 6 is a plate-like member having two opposing parallel surfaces, and is made of iron. The linear guide 4 is installed perpendicularly to the base 6, and the direction of movement of the weight is directed perpendicular to the ground surface.

Next, the operation will be described. First, the base 6 of this vibration exciter is placed on the ground surface such that the direction of movement of the weight is perpendicular to the ground surface. When the motor is rotated, the rotation of the motor is transmitted to the rotating shaft and the cam.
At this time, the rotating shaft does not generate vibration because the cam has a balanced mass. The weight repeatedly reciprocates in a substantially vertical direction by the rotation of the cam and the linear guide. When the weight moves substantially vertically upward, a force in the opposite direction to the force applied to the weight is generated at the installation location of the vibration exciter due to the principle of action / reaction. That is, the installation location receives a vertically downward force via the base 6. In this way, the ground vibrates only in the vertical direction.

As another embodiment of the invention, as shown in FIG. 3, a vibrator for supporting a weight using a leaf spring 8 or a vibration exciter shown in FIG.
As described above, there is an exciter that suspends a weight by using a winding spring 9 and supports the weight. However, in FIGS. 3 and 4, the bearing is omitted to make the cam 2 and the like easy to see.

[0020]

As described above, the vibration generator according to the first aspect can provide vibration in a linear direction with a simple mechanical structure.

According to the vibration exciter of the second aspect, since the weight of the weight can be changed, the vibration excitation force of the vibration exciter can be made variable, and vibrations of various wavelengths can be generated. In addition, it becomes very easy to carry the exciter.

According to the vibration generator of the third aspect, the moment generated by the rotation of the cam is canceled, and unnecessary vibration of the vibration generator can be suppressed. Therefore, vibration can be applied only to the ground in a linear direction.

[Brief description of the drawings]

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

FIG. 2 is an exploded perspective view of the vibration exciter according to the present invention.

FIG. 3 is an explanatory diagram showing another embodiment.

FIG. 4 is an explanatory diagram showing another embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rotary shaft 2 Cam 3 Weight 31 Weight 32 Base 4 Linear guide 5 Motor 6 Base 7 Bearing 8 Leaf spring 9 Winding spring

Claims (3)

[Claims] 1. A rotary shaft, a cam provided on the rotary shaft, a weight driven by the cam, and a support for supporting the weight so as to be able to reciprocate in a linear direction. And exciter. 2. The vibration exciter according to claim 1, wherein the weight of the weight is variable. 3. The vibration exciter according to claim 1, wherein the cam has a plate shape with a uniform thickness, and a rotation shaft is provided at a center of gravity of the cam.