JPH0460015A - Variable vibration generator - Google Patents

Abstract

PURPOSE:To obtain an optimum vibration characteristic with a simple structure and miniaturize the generator and reduce the cost by providing a movable weight movable nearly vertically to an eccentric weight, and interposing an elastic spring between the movable weight and a rotating shaft. CONSTITUTION:To a rotating shaft 1, a semi-circular or sector rotating eccentric weight 2 having a pair of guides 3 protruded thereon and integrally rotating with the shaft is fixed, and a movable weight 4 having an elliptic opening 5 and having a coil spring 6 mounted thereon is inserted with a play to the shaft 1 and interposed between the guides 3 in such a manner as to be capable of vertically sliding between them. Further, the eccentric quantity of the movable weight 4 by the rotation of the eccentric weight 2 is made variable by changing the angle speed (rotating speed) of the shaft 1 and the spring constant of the spring 6. The eccentric quantity of the weight 2 is changed while suppressing the synthesized centrifugal force within a fixed range to change the whole eccentric moment, whereby an optimum vibration characteristic is obtained according to the property of ground and the kind of work.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is capable of adjusting vibration characteristics based on amplitude and frequency according to work conditions without stopping the operation of the machine or without affecting the drive motor. This invention relates to a variable vibration generator that can be made variable.

[Prior Art] Conventionally, vibration generators (exciters) used in vibratory pile driving machines, vibratory rolling machines, etc., have a mechanism that uses centrifugal force to generate an excitation force. ing. The principle of generating the vibrational force is shown in FIG. 9. In general, as a mechanism for generating vibrations, a method in which a pair of unbalanced weights (eccentric weights) 2 are rotated at a constant speed is widely adopted. In particular, in a vibratory pile driver, the direction of vibration needs to be vertical, and the circular trajectory vibration generated by the rotation of the unbalanced weight 2 attached to the rotating shaft 1 is converted into vertical linear trajectory vibration. In order to do this, two shafts 1 are arranged horizontally in parallel, and the gears 1a mounted on both shafts 1 are meshed with each other. Then, one of the shafts is used as a drive shaft and is driven by a belt by an electric motor (not shown), and the shafts are rotated at a constant speed relative to each other to generate vertical vibration. That is, in FIG. 9(a), both weights 2 are on the lower side, and the resultant centrifugal force is 2F, which acts downward. The weight 2 further rotates as shown in (b)
), both centrifugal forces act in opposite directions and cancel each other out, becoming zero. Furthermore, when it rotates to the position shown in figure (C), a resultant force 2F of centrifugal force opposite to that shown in figure (a) acts upward. When it rotates further and reaches the position shown in Figure (d), the centrifugal forces cancel each other out as in Figure (D). In the end, only the centrifugal force acting in the vertical direction remains, which becomes the excitation force.

Note that the excitation force generated in the vibration generator is expressed by the following equation.

F=W-R・ω2/g (kgf) Where, W: Weight of unbalanced weight (eccentric weight) R: Amount of eccentricity (distance from the rotational axis to the center of gravity of the unbalanced weight) ω: Angular velocity g :Gravity acceleration.

By the way, when driving or pulling out piles using a vibrating pile driver, or when compacting the ground using a vibrating roller, in order to obtain optimal conditions, it is necessary to The excitation force may be changed depending on the nature of the ground. As mentioned above, in conventional vibration generators that generate vibrational force using centrifugal force, the eccentric moment is increased or decreased in order to do this.

The first method of increasing or decreasing the eccentric moment is
As shown in Figure 0, the entire center of gravity of the unbalanced weight 2 can be moved from G to Go by inserting a lead rod P into the hole 0 provided in the unbalanced weight 2 and covering it with a cover from the outside. It was by changing up to. The work of attaching and detaching the lead rod P is complicated and involves disassembling the main body of the machine, and the operation of the machine must be stopped when attaching and detaching the lead rod P, which is one of the causes of deterioration of work efficiency.

Therefore, in order to solve this problem, several proposals have been made.
No. 170 (Conventional Example 3) and Japanese Patent Publication No. 61-47934 (Conventional Example 4).

Conventional example 1 has a gear fixed to a variable shaft directly connected to the swing motor, and a separate rotating shaft with an eccentric weight (fixed weight) parallel to this variable shaft, and this rotating shaft has an eccentric moment increase/decrease. A sleeve having an eccentric weight (variable weight) and gears is attached, and the gears mesh with each other. When the swing motor is operated hydraulically, the variable shaft rotates, and the sleeve rotates on the rotating shaft via a gear, and the eccentric moment increases or decreases by changing the relative angle between the variable weight and the fixed weight on the rotating shaft. It is supposed to be done.

Conventional Example 2 and Conventional Example 3 similarly attempt to increase or decrease the eccentric moment by changing the relative angle of the eccentric weight.
The former is achieved by raising and lowering the adjustment shaft via several gears driven by a hydraulic cylinder, while the latter is achieved by a worker operating the open shaft and adjustment shaft that protrude outside the machine body from the outside. By doing so, the relative angle between the fixed weight and the movable weight can be changed arbitrarily.

In Conventional Example 4, the rotational speed of an engine-driven generator that supplies power to the exciter is controlled so that the vibration frequency of the exciter is made variable.

[Problem to be solved by the invention]

All of the eccentric moment variable devices of Conventional Examples 1 to 3 are extremely complicated due to the increased number of gears, shafts, etc., and the mechanism itself is also complicated, so the vibration generator body becomes large.
This has the disadvantage that the weight of the device also increases. Conventional example 1.2
In this case, another power source (drive device) is required to change the relative angle of the eccentric weight. Further, in the case of Conventional Example 3, it is necessary to change the relative angle of the eccentric weight by manual operation, which is time-consuming.

In Conventional Example 4, the electrical control device is extremely complicated, and
An increase in the weight of the device is unavoidable, and an inexpensive vibration generator cannot be provided.

By the way, in a vibratory pile driver, there is an optimal combination of amplitude and frequency for pile driving work and drilling work.

In other words, it has been found that for boat fishing, it is much more efficient to use a large amplitude and small vibration frequency when driving piles, and a small amplitude and large vibration frequency when pulling out piles.

However, none of the conventional examples described above take this point into consideration, and it is considered that it is not possible to select and adjust the optimal combination of amplitude and frequency depending on the type of work. Moreover, in this case, when converting work that was performed with a large amplitude and small vibration frequency to a small amplitude and large vibration frequency, the centrifugal force generated is constant so that the fluctuation of the power for driving the rotation of the eccentric weight is within the allowable range. It is necessary to suppress it within a range, and a means or mechanism for that purpose is essential, but this is not considered in the above conventional example. Otherwise, if fluctuations in centrifugal force are allowed to occur without limit, a power source with an extremely large and uneconomical capacity would have to be equipped to handle this, and in some cases, the device itself would become unsustainable. This is because there is a possibility.

In view of such conventional problems, the present invention provides a variable vibration generator that achieves changes in eccentric moment with an extremely simple mechanism. It is an object of the present invention to provide a variable type vibration generator having a mechanism capable of keeping the synthetic centrifugal force within a substantially constant range so that the power remains substantially constant even when the optimal value is selected.

[Means to solve the problem]

To achieve the above object, a first aspect of the vibration generator of the present invention is a vibration generator that changes the vibration characteristics by changing the relative angle of the eccentric weight. A movable weight is provided on the rotating shaft so as to be movable in a substantially perpendicular direction, and an elastic spring is interposed between the movable weight and the rotating shaft.

A second invention is a vibration generator that changes vibration characteristics by changing the relative angle of eccentric weights, in which a pair of eccentric weights are symmetrically rotated relative to a rotating body that rotates integrally with one rotating shaft. The eccentric weight is supported so that the axial support point of the eccentric weight is offset with respect to the axis of the rotating shaft.

A third invention is a vibration generator that changes the vibration characteristics by changing the relative angle of the eccentric weights, in which a pair of eccentric weights are mounted concentrically on one rotating shaft so as to be relatively rotatable symmetrically; The present invention is characterized in that a control means for forcibly changing the relative angle between the eccentric weights is provided.

A fourth invention is a vibration generator that changes the vibration characteristics by changing the relative angle of eccentric weights, in which an odd number or an even number of eccentric weights are attached to one rotating shaft, and at least one of the eccentric weights is The movable eccentric weight is configured to be rotatable relative to the rotating shaft, and the other eccentric weights are fixed eccentric weights that rotate integrally with respect to the rotating shaft. [Function] In any of the configurations of the above invention, the locking means is provided between the fixed eccentric weight and the locking means can be rotated in conjunction with the fixed eccentric weight. Optimal vibration characteristics are achieved with a simple configuration, while suppressing the synthetic centrifugal force within a certain range.
This can be obtained by changing the amount of eccentricity of the entire eccentric weight with respect to the axis of the rotating shaft to change the overall eccentric moment. Further, except for the fourth invention, the vibration characteristics can be adjusted steplessly. In particular, in the case of the first and second inventions, a preset amplitude change is automatically obtained depending on the magnitude of the rotational speed (angular velocity) (that is, the magnitude of the vibration frequency), and as a result, the desired vibration characteristics can be obtained. It will be done.

In addition, especially in the third invention, since the pair of eccentric weights can be forcibly brought to any position by operating the control means, a balancing effect is exerted at the time of start-up, the starting torque is small, and the start-up is smooth. . In other words, it is possible to prevent the generation of excitation force at unnecessary times such as during startup.

Furthermore, in the fourth invention, the eccentric moment of the entire eccentric weight can be changed with a simpler configuration, and the vibration characteristics can be adjusted in two stages.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

The principle of generating the vibrational force of the present invention also employs the conventional principle described above. Therefore, as described above, the excitation force in the vibration generator is expressed by the following equation.

F=W-R・ω2/g Here, W: Weight of unbalanced weight (eccentric weight) R: Amount of eccentricity ω: Angular velocity g: gravitational acceleration It is.

According to the above equation, it can be seen that even with the same excitation force, different vibration characteristics can be obtained by changing the combination of WR and ω.

FIGS. 1 and 2 show basic embodiments of the present invention (first, second).
Embodiment) FIG. 1(a) is an exploded perspective view of a main part of an excitation force generating section, and FIG. 1(b) is a front view. These figures show that, as shown in FIG. 9, there is actually a pair of eccentric weights attached to the rotating shafts on both sides, and both are configured to rotate at a constant speed via gears. Here, only one side is shown for convenience.

As shown in Fig. 1, a semicircular or fan-shaped eccentric weight 2 is fixed to a rotating shaft 1 (a fixed eccentric weight attached to the rotating shaft 1 so as to rotate integrally with the rotating shaft 1 is referred to as a "fixed eccentric weight"). This fixed eccentric weight 2 has a pair of guides 3 on both sides of the rotating shaft 1.
It is integrally protruded from the front of the. On the other hand, a movable weight 4 having an oval opening 5 at an eccentric position is attached to the rotation axis l.
A coil spring (elastic spring) 6 is inserted between the rotary shaft 1 and the lower part of the opening 5 of the movable weight 4, and is arranged to be freely slidable up and down between the guides 3. is interposed, and the movable weight 4 is configured to be movable up and down against the spring force. Further, after the movable weight 4 is set between the guides 3, it is covered with a rectangular cover plate 7. In other words, cover plate 7
is attached to the front of the guide 3 with bolts or the like.

Although FIG. 2 has almost the same configuration, in the case of the second embodiment shown in FIG. The points are different. The cover plate 7 is also made to match the shape of the eccentric weight 2.

FIG. 3(a) is a mechanical schematic diagram of the first embodiment.

As shown in FIGS. 1 and 3(a), when the rotating shaft l is now rotated at a rotational angular velocity ω, the eccentric weight 2 rotates while holding the movable weight 4.

The eccentric weight 2 rotates with its center of gravity G being an eccentric amount R (this does not change) from the rotation axis center O.

When the eccentric weight 2 rotates, a centrifugal force acts on the movable weight 4, and when the rotational angular velocity exceeds a certain rotational speed, the movable weight 4 protrudes from the end surface of the guide 3 against the spring force of the coil spring 6.

At this time, the center of gravity G0 of the movable weight 4 moves to G1. That is, the center of gravity G of the movable weight 4 is calculated from the initial eccentricity before rotation (distance from the center of the rotation axis l) ro to the eccentricity r,
Changes to In this way, the center of gravity G of the movable weight 4. The amount of eccentricity with respect to the center of the rotating shaft is the angular velocity ω(
It is configured to vary depending on the rotation speed). This amount of eccentricity can also be changed by changing the spring constant of the coil spring 6, and is appropriately selected and set in accordance with the weight center of gravity and rotational speed of the eccentric weight at the device design stage depending on what kind of vibration characteristics are to be obtained. It is something that

Thus, in the above configuration, the following effect occurs as the amount of eccentricity of the movable weight 4 changes during the rotation of the eccentric weight 2.

Now, the centrifugal force F generated by the eccentric weight 2 is as follows: F=W−R·027g (1). On the other hand, the centrifugal force r generated by the movable weight 4 is f = w − r + ・(IJ2/ g −・”(
2).

Since the centrifugal force F of the eccentric weight 2 and the centrifugal force r of the movable weight 4 act in directions that cancel each other out, the centrifugal force as a whole (hereinafter referred to as "synthetic centrifugal force j")
becomes F−f. By suppressing this value within a substantially constant range, it becomes possible to change the vibration characteristics without affecting the power source in any way.

To express the above points with concrete numerical values, let us assume that the weight of the eccentric weight 2 is w = 800 kg, the eccentricity R = 20 cm, the weight of the movable weight 4 is w - 210 kg, the initial eccentricity ro = 8 cm, and the spring constant is k. = 1400 kg/cm.

Under this setting condition, rotation speed N (rpm) (rotational angular velocity ω
= 2πN /60) within the normal operating range, that is, between approximately 560 and 680 rpm, and the result of calculating the resultant centrifugal force is shown in Figure 3 (b). become.

In this figure, the vertical axis represents centrifugal force, and the horizontal axis represents rotational speed. The curve shown by the solid line is the centrifugal force due to the fixed weight, that is, the fixed eccentric weight 2, and the dashed line is the movable weight 4.
The dotted line shows the combined centrifugal force, which is the combination of both centrifugal forces.

According to this figure, it can be seen that the synthetic centrifugal force is within a substantially constant range within the range of normal rotational speeds. This means that even if the vibration characteristics are changed from, for example, a small amplitude and ten-person frequency to a large amplitude and a small frequency, the power source will not be affected at all. For example, even if an inverter-type electric motor that can change the rotation speed steplessly is used as a drive source, the fluctuation can be kept within the permissible range, and there is no need to equip a large-capacity drive motor to change the vibration characteristics. It is something.

Furthermore, this embodiment has the advantage that stepless vibration characteristics can be obtained depending on the rotational speed (angular velocity).

4 to 8 show variations of the above embodiment. In the third embodiment shown in FIG. 4, the fan-shaped rotating body 8 is
A pair of fan-shaped eccentric weights 9 provided symmetrically on both sides of the upper part of this rotating body 8 allow relative rotation (oscillation).
The eccentric weights 9 are freely supported (hereinafter also referred to as "movable eccentric weights J").The eccentric weights 9 are connected to the lower part of the rotating body 8 via coil springs 10. .OI indicates the center of the rotating shaft, and 0□ indicates the center of the shaft fulcrum.Therefore, both have an eccentricity of !.

When the rotating shaft 1 is rotated, the eccentric weights 9 also rotate together with the rotating body 8, but as the rotational angular velocity (that is, the number of rotations) increases, the pair of eccentric weights 9 resist the spring force of the coil spring 10 and move away from each other. (opening direction).

The reason for this is that when the rotating shaft 1 rotates, a centrifugal force f acts on the eccentric weight 9, and the centrifugal force fx! This is because when the rotational moment acts and the rotational speed increases, both eccentric weights 9 rotate around the center 02 in the direction of mutual opening and move away. Then, each eccentric weight 9
By reducing the amount of eccentricity of the two eccentric weights 9
The synthesized center of gravity position (not shown) is the center 01 of the rotation axis 1
approach. In this way, even if the angular velocity increases, the amount of eccentricity of the entire eccentric weight 9 decreases, so that the centrifugal force does not increase and is suppressed within a certain range.

FIG. 5 shows an attempt to forcibly control the opening (relative angle) of both eccentric weights 9 by connecting a pair of movable eccentric weights 9 with a fluid cylinder 11 serving as a relative angle control means. In this case, the fluid piping 12 conducts through the rotating shaft 1 and is led to the fluid cylinder 11 . In the embodiment described above, the spring constant of the coil spring must be appropriately selected, but in this fourth embodiment, the amount of eccentricity of the eccentric weight 9 can be forcibly controlled, which is convenient. In other words, with this configuration, when the drive motor is started, if the fluid cylinder 11 is extended and the two eccentric weights 9 are brought to a balance position, that is, a position where the centrifugal forces cancel each other out, no excitation force is generated. , the starting force (starting torque) can be small. Then, as the rotation speed increases, the fluid cylinder 11 is shortened to change the phase of the two eccentric weights 9, that is,
Control is performed to reduce the relative angle between the two. In this way, the same effect as in the embodiment described above can be obtained.

In the fifth embodiment shown in FIGS. 6(a) and 6(b), an eccentric shaft IA with an enlarged diameter is formed on the rotating shaft 1, and a pair of fan-shaped movable eccentric weights 9 are attached to the eccentric shaft IA so as to be relatively rotatable. has been done. The lower portions of the eccentric weights 9 are connected to each other by a coil spring 13. 01 indicates the center of the rotation axis 1,
02 indicates the center of the eccentric axis IA. Therefore, for both! The amount of eccentricity is provided. The operation in this case is also similar to the embodiment described in FIG. That is, when the rotating shaft 1 rotates, a centrifugal force f acts on the eccentric weight 9. Then, a rotational moment of centrifugal force fx1 acts on the eccentric weights, and as the rotational speed increases, both eccentric weights 9 rotate in a direction in which they are opened to each other (in a direction in which the relative angle becomes larger) against the spring force of the coil spring. move and move away. Compared to the example shown in FIG. 4, this example has the advantage that the fan-shaped rotating body can be omitted and the device is simplified.

In the sixth embodiment shown in FIG. 7, a hydraulic low reactor 1 is used instead of the fluid cylinder in the embodiment of FIG.
4 to forcibly control the relative angle of the two movable eccentric weights 9 according to the angular velocity. The advantage of this embodiment is that, as in FIG. 5, when the drive motor is started, hydraulic pressure is applied to chamber B to balance the two eccentric weights 9 and bring them to a position where the centrifugal forces cancel each other out. The reason is that it requires less starting force. Then, as the rotational speed increases, by applying hydraulic pressure to chamber A and decreasing the phase of the two eccentric weights, that is, the relative angle between them, the same effect as in the other embodiments can be obtained.

In the seventh embodiment shown in FIGS. 8(a) and 8(b), three eccentric weights 15, 15, and 16 are arranged in parallel, of which the eccentric weights 15 on both sides are fixed eccentric weights fixed to the rotating shaft 1. It is. The central eccentric weight 16 is the rotation axis 1
It is configured as a movable eccentric weight that is pivotally supported for relative rotation. Moreover, this central movable eccentric weight 1
A locking rod 17 is provided on the upper surface of 6 so as to protrude in the width direction thereof. In the state shown in FIG. 8(a), the central eccentric weight I6 is connected to the other eccentric weights 15 on both sides by the locking rod 1.
It is locked via 7. In this state, when the rotating shaft 1 is rotated in the direction of the arrow X, the central eccentric weight 16 is also rotated together with the eccentric weights 15 on both sides. In this case, since the eccentric weight with the largest combined weight is rotating, a large-amplitude excitation force can be obtained. On the other hand, when reversely rotated in the direction of arrow Y, the eccentric weights 15 on both sides are rotated as shown in FIG.
As shown in b), apart from the central eccentric weight 16, the entire body becomes disc-shaped when viewed from the front, and the locking rods 17 fit into the locking grooves 18 formed in the eccentric weights 15 on both sides. In this state, the three eccentric weights 15, 15, and 16 begin to rotate. In other words, the locking rod 17 and the locking groove 18 constitute a locking means. In this case, half of the weight of the eccentric weights 15 on both sides is canceled by the central eccentric weight 16 (in other words, the position of the composite center of gravity of the three eccentric weights approaches the center of the rotation axis,
(the amount of eccentricity decreases), and the vibration characteristics change to a small amplitude. Thus, in this embodiment, the vibration characteristics can be easily changed depending on the direction of rotation of the rotating shaft. However, whereas in the previous embodiments the vibration characteristics could be adjusted steplessly,
This example is a type that allows only two-step adjustment.

Therefore, the power source for rotating the eccentric weight may be a pole change type electric motor instead of an inverter type having a function of changing the rotation speed. This embodiment is suitable for a vibratory pile driver, and is superior to other embodiments in that it can achieve the optimum combination of amplitude and vibration frequency with the simplest configuration depending on the type of pile driving and pile extraction work. It can be said that it looks better.

Although the above configuration shows the case of three eccentric weights, it is also possible to equip a fishing boat with an odd number of eccentric weights to achieve the same effect, or to use an even number of eccentric weights. However, it is clear that the same effect can be obtained by configuring each eccentric weight to have a different center of gravity.

〔Effect of the invention〕

According to the present invention described above, the following effects can be obtained.

(a) When working with vibratory pile drivers, vibrating compaction machines, etc., achieve optimal vibration characteristics depending on the nature of the ground or the type of work while suppressing the synthetic centrifugal force within a certain range. A vibratory pile driver or compacting machine that can perform the following tasks can be obtained with a simple configuration. As a result, it becomes possible to construct a lightweight, compact, and inexpensive machine.

In particular, in the case of the first and second inventions, a desired vibration characteristic can be obtained as a result of automatically obtaining a predetermined amplitude in accordance with the rotational speed (angular velocity), that is, a predetermined vibration frequency. Moreover, stepless vibration characteristics can be obtained except for the fourth invention.

(b) By making it possible to forcibly change the relative angle of a pair of eccentric weights, a balance effect can be obtained and vibrational force can be prevented from being generated when unnecessary, such as during startup. can. Therefore, the starting force (starting torque) of the drive motor can be small, and a small and small capacity motor can be used. As a result, damage to the electric motor due to overcurrent during startup can be prevented, and a device with high reliability can be obtained.

(C) In the case of the fourth invention, with a simpler configuration, the vibration characteristics can be adjusted in two stages by selecting the rotation direction.

[Brief explanation of drawings]

1 to 8 show embodiments of the present invention, and FIG.
a) and (b) are an exploded perspective view and a front view of a main part of an excitation force generating section according to the first embodiment, and No. 21 is an exploded perspective view of an important part of an excitation force generation section according to a second embodiment. 3(a) and 3(b) are schematic mechanical diagrams of FIG. 1 and their working circles, FIG. 4 is a front view of the main part of the vibration force generating section according to the third embodiment, and FIG. 5 is a diagram of the fourth embodiment. FIGS. 6(a) and 6(b) are front views of the main parts of the vibrational force generating part according to the fifth embodiment, and FIG. 7 is a front view of the main parts of the vibrational force generating part according to the fifth embodiment. 8(a) and 8(b) are front views of the main parts of the vibration-exciting force generating part according to the sixth embodiment, and FIG. FIG. FIGS. 9(a) to 9(d) are diagrams showing the principle of a conventional general vibration generator, and FIG. 10 is a diagram showing an example of a conventional method for changing the eccentric moment. 1... Rotating axis, IA... Eccentric axis, 2.15... (
fixed) eccentric weight, 4...movable weight 9, I6...
...(movable) eccentric weight, 6.10.13... coil spring (elastic spring), 11... (relative angle) control means, 7... locking rod, 8... locking groove.

Claims (4)

[Claims] (1) In a vibration generator that changes the vibration characteristics by changing the relative angle of the eccentric weight, a fixed eccentric weight fixed to one rotating shaft is provided with a movable weight so as to be movable in a direction substantially perpendicular to the rotating shaft. A variable vibration generator characterized in that an elastic spring is interposed between a movable weight and the rotating shaft. (2) In a vibration generator that changes the vibration characteristics by changing the relative angle of the eccentric weights, a pair of eccentric weights are symmetrically supported for relative rotation on a rotating body that rotates integrally with a rotating shaft. . A variable vibration generator, characterized in that the fulcrum of the eccentric weight is offset from the axis of the rotating shaft. (3) In a vibration generator that changes the vibration characteristics by changing the relative angle of the eccentric weights, a pair of eccentric weights are mounted concentrically on one rotating shaft so as to be relatively rotatable symmetrically, and the eccentric weights of the pair are A variable vibration generator characterized by being provided with a control means that can forcibly change the relative angle between weights. (4) In a vibration generator that changes the vibration characteristics by changing the relative angle of the eccentric weights, an odd number or an even number of eccentric weights are attached to one rotating shaft, and at least one of these eccentric weights is The movable eccentric weight is configured to be rotatable relative to the axis, and the other eccentric weight is a fixed eccentric weight that rotates integrally with respect to the rotation axis, and the movable eccentric weight and the fixed eccentric weight are combined. A variable vibration generator characterized in that a locking means that can rotate together is provided between the vibration generator.