JP2724296B2 - Excitation weight control method and control mechanism for eccentric weight - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for driving a rotary exciter for driving a pile and for controlling a vibrating function, and a mechanism therefor.

[0002]

2. Description of the Related Art In general, a vibration device (vibrator) used for civil engineering construction has a structure in which a plurality of pairs of rotating shafts having eccentric weights mounted thereon are arranged in parallel. According to such a configuration, the centrifugal vibrating force of the eccentric weight rotating in the opposite direction can be added in a desired direction and can be offset in an unnecessary direction. When a pile driving operation is performed using the above-described exciter, prevention of vibration pollution and prevention of noise pollution are important issues. Next, a technical problem relating to vibration pollution will be described with reference to FIGS.

FIG. 4 is a schematic diagram for explaining vibration pollution in a pile driving operation. This figure shows a state in which the vibration device 6 is suspended by the crane boom 5, the upper end of the pile 7 is gripped by the chuck 6 a of the vibration device 6, and the pile 7 is vibrated and driven into the ground. Is drawn. When the lower end of the pile 7 is brought into contact with the ground surface to start the pile driving operation, if the vibration device 6 is fully operated from the beginning, the surface wave a generated on the ground at the pile driving point is hardly attenuated and the nearby private house 8 , Causing vibration pollution problems. Here, if the vibrating force of the vibrating device 6 can be adjusted arbitrarily, the pile driving operation is started while giving a slight vibration in addition to the weight of the pile 7, and after driving several meters, the vibration may be gradually increased. . If the hypocenter position corresponding to the lower end of the pile 7 becomes deeper, the underground wave b attenuates on the way to the private house 8, so that the vibration pollution is negligible.

FIG. 5 is a table showing changes in the vibration frequency at the time of starting operation and at the time of stopping the operation of the vibration device. The horizontal axis represents time. Start of operation time t _0, between time t ₁ to reach the rated operating state, frequency rises sharply as shown by arrow c. During the above frequency rise, the natural frequency of the ground n ₁ and the natural frequency of the crane boom n ₂ are passed. However, since the rotational speed increase period T ₁ at the start operation is generally short (e.g., about 3 seconds), the resonance problem when frequency of the vibration device matches the natural frequency, can be usually ignored it can. However, between the time t ₂ of stopping the energization of the motor of the vibrating device 6 (not shown) to the time t ₃ when the rotary shaft is stopped is gradually decelerated as indicated by the arrow d while continuing to rotate at a rotational axis of inertia . The above-mentioned rotation speed reduction period T
_{Since 2} is a relatively long time (for example, about 50 seconds), there is a possibility that the crane boom will resonate and be damaged when passing the natural frequency n ₂ of the crane boom on the way. Further, when passing through the natural frequency n ₁ of the ground, there is a possibility that vibration pollution may occur due to resonance of the ground. The time t
_{If the} motor could be de-energized in step ₂ and the vibrating device could change the rotational phase of the vibrating device's rotating weight to zero the vibrating force, it would be possible to prevent problems related to resonance during the operation of stopping the vibrating device. Can be.

Next, looking at the amount of energy supplied to the vibrating device, the vibrating device 6 from time t ₀ to t ₁ described above.
If the speed is increased while the vibration is generated by the eccentric weight (not shown) of the vibration device while the rotation speed of the vibration device is increasing, a large-capacity motor or a large-capacity power supply facility is required to drive the vibration. . In this case, the operation is started in a state where the vibration force is reduced to zero by changing the rotation phase of the eccentric weight of the vibration device, and if the vibration force can be exerted after reaching the rated rotation speed,
It is economical because the motor capacity and power supply capacity can be reduced.
This is because, after reaching the rated rotation speed, there is no need to store any more rotational energy in the rotating member, and the operation can be continued by replenishing energy sufficient to compensate for the attenuation of vibration.

[0006] In view of the above circumstances, an adjustment technique for increasing or decreasing the vibrating force of a vibrator has been developed and is known. Next, the principle of increasing and decreasing the vibrating force of the vibrator will be described. FIG. 6 is a view for explaining a known technique for changing a vibrating force by a combination of two eccentric weights, and FIG. 6A shows two eccentric weights exhibiting a maximum vibrating force. FIG. 3B is a schematic diagram illustrating a state in which the vibrating force is medium, FIG. 3C is a schematic diagram illustrating a state in which the vibrating force is slightly small, and FIG. FIG. Of the two eccentric weights shown in FIG. 6A, 9 is a fixed eccentric weight fixed to the rotating shaft 2B ', and 10 can rotate relatively to the rotating shaft 2C'. It is a movable eccentric weight. In the present invention, the fixed eccentric weight is an eccentric weight that is locked with respect to the rotation axis and is a member that rotates together with the rotation axis. . The relative positions of the two eccentric weights 9 and 10 in FIG. 6A are in a state where the phase difference is zero.

Therefore, when the two eccentric weights 9 and 10 are rotated in synchronization with the gears 4B 'and 4C' in the state shown in FIG. 6A, a vibrating force is generated. In the state of FIG.
Since the center of gravity of each of the two eccentric weights 9 and 10 is always symmetric with respect to the reference line MM (vertical bisector of the line connecting the two rotation axes 2B 'and 2C'), The excitatory force in the direction is zero. For convenience of explanation, a state where the phase difference between the two eccentric weights is 180 degrees and the total eccentric moment of the two eccentric weights is zero as shown in FIG. 6D is referred to as a reference state. 6 (B) and 6 (C) are intermediate states of the above (A) and (D), respectively, so that the vertical vibrating force is smaller than in the case of (A) and larger than in the case of FIG. Occurs. (B) is closer to the state of (A) than that of (C), so that (A), (B), (C), (D) ). In order to show the principle of the vibrating force increase / decrease control in FIG.
The two rotating shafts 2B ', 2C' are connected to the synchronous rotating gears 4B ', 4B.
Although it is depicted as being rotated synchronously at C ', two eccentric weights can be arranged on one rotating shaft to simplify the structure. FIG. 7 is a schematic diagram of a mechanism in which a fixed eccentric weight is fixed to a common rotating shaft and the movable eccentric weight can adjust the relative rotation angle position with respect to the common rotating shaft.

The fixed eccentric weight 9 is fixed to the rotating shaft 2 and rotates together. The movable eccentric weight 10 can be adjusted by changing the mounting angle position with respect to the rotating shaft 2 as shown by the arc arrows α-β, and can maintain the adjusted state. The state depicted in FIG. 7 is shown in FIG.
Exciting force is moderate, corresponding to the state shown in (B).
When the movable eccentric weight is rotated and fixed in the direction of the arrow α from this state, the state approaches the state of FIG. 6A, the vibrating force is increased by approaching the state shown in FIG. The vibrating force is adjusted as described above. FIG. 8 shows the principle in FIG.
FIG. 11 is a perspective view showing a conventional example of a vibration exciter in which a fixed eccentric weight and a movable eccentric weight are arranged with respect to one common axis so that a vibration force can be increased or decreased. The reason why the two rotating shafts 2A and 2B are arranged in the horizontal direction and are synchronously rotated in the opposite directions (clockwise and counterclockwise) by the driving pulley 11 and the synchronous rotation transmission gears 4A and 4B is the horizontal direction. This is to offset the vibrating force. The fixed eccentric weight 9A is fixed to the rotating shaft 2A. The movable eccentric weight 10A is rotatably supported on the rotary shaft 2A, and can adjust and fix the rotation with respect to the fixed eccentric weight 9A. That is, the movable eccentric weight 10A has a plurality of adjusting female screw holes (only one is shown in the figure) 12
Is pierced. Set bolt 14 into female screw hole 12
And tighten it with a hexagon wrench 15
When the rotation is stopped by the above, the angular position of the movable eccentric weight 10A is fixed. FIG. 9 illustrates the relationship between the rotating shaft, the fixed eccentric weight, and the movable eccentric weight in the conventional exciter having the adjusting mechanism shown in FIG. FIG. 2 is an external perspective view partially cut and drawn, and FIG. 2B is a schematic view illustrating a portion viewed in a direction parallel to a rotation axis.
Reference numerals 23a, 23b, and 23c shown in FIG. 9A are scales, and the unit is kg · cm. By setting the scale and screwing the set bolts together, as shown in FIG.
The movable eccentric weight takes three angular positions, 10a, 10b,
The vibrating force is changed by relatively rotating as shown in 10c.
The exciter according to the prior art shown in FIGS. 7 to 9 can increase or decrease the excitatory force as described above.

[0009]

When an attempt is made to increase or decrease the excitation force in the conventional exciter described with reference to FIGS. 7 to 9, it is easily understood from the structure shown in FIG. As shown in FIG. 9, the operation is stopped, the knock pin 13 is pulled out, the set bolt 14 is pulled out, and the movable eccentric weight 10 is manually turned to indicate the scale (reference numerals 23a to 23 in FIG. 9).
After setting 3c), the set bolt 14 must be screwed again, tightened, and detented with the knock pin 13.
In the prior art, the above operations are required to adjust the increase and decrease of the vibrating force. As already described with reference to FIG. 4, since the vibrating device 6 is attached to the upper end of the pile 7, it is suspended by the crane boom 5 and adjusted.
The work of lifting up the crane boom 5 and attaching it to the upper end of the pile 7 again requires a lot of time and labor. The structure in which the fixed eccentric weight 9 and the movable eccentric weight 10 are respectively mounted on different rotating shafts as shown in FIG. It is also conceivable to increase or decrease the vibrating force while adjusting the movable eccentric weight 10 by 180 degrees between the state shown in FIG. 6A and the state shown in FIG. (Relatively) and the structure becomes complicated. In particular, the mechanism for performing servo control while detecting the rotational phase of the fixed eccentric weight and the rotational phase of the movable eccentric weight while connecting these eccentric weights to each other becomes complicated and expensive. Requires great skill and great effort.

The present invention has been made in view of the above circumstances, and there is no need to detect the rotational phase of an eccentric weight or to servo-control the rotational drive of an eccentric weight.
It is an object of the present invention to provide a control method and a control mechanism capable of preventing vibration pollution in a pile driving operation by increasing or decreasing the vibrating force of the vibration exciter while continuing the operation of the vibration exciter without interruption. And

[0011]

The basic principle of the present invention created to achieve the above object (simplification of the control mechanism) is briefly described below with reference to FIG. . That is, at the time of starting operation, what is necessary for pollution prevention and crane boom protection is to set the total eccentric moment of the eccentric weight to zero at the point o where the rotation of the exciter starts, and to start the steady operation. At the point i, the above total eccentric moment may be maximized. In other words, the rotational phase difference between the two vibration units is 18
It is sufficient to start at 0 degree and start at zero excitation force (point o), and at point i where the operation shifts to the steady operation, set the rotational phase difference to 0 degree to exhibit the maximum excitation force. Similarly, what is necessary to prevent pollution and protect the crane boom at the end of the operation is that the rotational phase difference is 18 at the point j at which the operation shifts from the steady operation to the inertia operation.
What is necessary is just to set it to 0 degree and to make excitation force zero. If say further summarize, the speed range corresponding to the natural frequency n ₂ of the natural frequency n ₁ and a crane boom of the ground, the rotational phase difference 18
It only has to pass at 0 degrees. It goes without saying that during the steady operation from the point i to the point j, the rotational phase difference must be maintained at 0 degree to exert the maximum vibrating force. From the above considerations, it is clear that the control of the rotational phase difference between the two series of excitation units is sufficient if the operation of switching between the 0-degree state and the 180-degree state is performed. It means that precise servo control over the whole can be omitted.

The basic principle of the present invention is to provide an eccentric weight type vibration generating mechanism for both the A and B systems so that the rotational phase difference between the rotating members of the A and B systems does not become smaller than 0 degree, and 180 degrees. In order not to exceed the degree, mechanical restraint is performed within an allowable angle of 180 degrees, and both the A and B systems are rotationally driven by motors. However, what has been described above is the basic principle, and it is not always necessary to make the excitation force zero when the excitation force is reduced. As a practical matter, the pile will not sink into the ground by its own weight alone unless a vibrating force that does not cause vibration pollution or resonance damage of the crane boom is left.

The above-mentioned A system and B system are names for convenience of explanation, and the names can be interchanged. However, in the present invention, the phase can be relatively advanced by about 180 degrees from the state where the rotational phase difference between the eccentric weights of both the A and B systems is adjusted to be zero. The system that can not be delayed from the state is defined as system A, and the system that can be relatively delayed by about 180 degrees from the state where the phase difference is adjusted to zero as described above, and the system that cannot be advanced from the aligned state is defined as system B. I do. That is, from the state where the rotational phase difference is zero, the system A can be advanced by about 180 degrees, and the system B can be delayed by 180 degrees.
It is agreed that the A system leads by about 180 degrees relative to the B system, and that the B system lags by about 180 degrees relative to the A system. Therefore, when one of the two systems A and B is rotating while pressing the other, the phase relationship between the two systems A and B is as follows.
Either about 180 degrees ahead of the system and the total eccentric moment is minimum, or (ii) the rotational phase difference between both the A and B systems is zero and the total eccentric moment is maximum.

Based on the principle described above, a specific configuration of the drive / control device of the vibration exciter according to the present invention is shown in FIG.
A drive and transmission system consisting of two systems, A system and B system, is provided, and the A system fixed eccentric weight (2
6) is fixed, and the A-system movable eccentric weight (29) is rotatably fitted to the B-system rotating shaft, so that the A-system fixed eccentric weight (26) and the A-system movable eccentric weight are rotated. Weight (2
9) is provided at all times in the opposite direction at the same rotational speed, and the B-system fixed eccentric weight (28) and the B-system movable eccentric weight (27) are always rotated in the opposite direction at the same rotational speed. And a mechanical means for restricting the phase difference between the rotation phase of the system A and the rotation phase of the system B within a predetermined angle range of 0 degree or more and 180 degrees or less. And an A-system drive motor (M) that rotationally drives the A-system rotation shaft (21).
a) and a B-system drive motor (Mb) for rotating and driving the B-system rotary shaft (22).
It is characterized in that the drive motors (Ma, Mb) of both systems can be individually controlled.

In the above configuration, the fixed eccentric weight of the system A and the movable eccentric weight of the system A always have a constant phase difference (1).
80 degrees), and the fixed phase difference between the fixed eccentric weight of the B system and the movable eccentric weight of the B system is always constant (180 degrees).
), And the phase difference between the fixed and movable eccentric weights of the system A and the fixed and movable eccentric weights of the system B is constrained to be within a predetermined angle range. Therefore, A
When the fixed and movable eccentric weights of the system A are rotationally driven by the drive motor of the system, the fixed and movable eccentric weights of the system B cannot be delayed more than a predetermined angle from the system A, and the weights of the fixed and movable eccentric weights of the system B are limited to a maximum angle within a predetermined angle range. Late (pulled by system A)
It rotates in the same direction at the same rotational speed as the A-system and operates in the state of the maximum eccentric moment to generate the maximum vibrating force. When the fixed and movable eccentric weights of the B system are rotationally driven by the drive motor of the B system, the fixed and movable eccentric weights of the A system which cannot advance more than a predetermined angle than the B system are within a predetermined angle range. (In the form of being pushed by the B system) and rotating in the same direction at the same rotational speed as the B system to operate in the state of the minimum eccentric moment and generate the minimum vibrating force. To summarize the above operation, without detecting the rotational phases of the A and B systems or performing servo control, and without interrupting the operation of the vibration exciter, one of the two drive motors is used. By a simple operation of which one causes the exciter to be rotationally driven, it is possible to arbitrarily select one of a state in which the maximum excitation force is generated and a state in which the minimum excitation force is generated.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of the present invention will be described with reference to FIGS. FIG. 1 schematically shows an exciter provided with one embodiment of an eccentric weight excitation force control mechanism according to the present invention configured to carry out the excitation force control method of the present invention. It is a horizontal sectional view. Depending on the case 1, two horizontal shafts, that is, the A-system rotating shaft 21
And the B-system rotary shaft 22 are rotatably supported. An A-system drive gear 23 is fixed to the A-system rotary shaft 21 via a key 24. In FIG. 1, seven keys are drawn, and only one symbol is attached. However, the drawing of the key means that the key is fitted so that it cannot rotate relative to the rotation axis. It shows that it is done. A portion where the key graphic is not drawn indicates that the key is fitted so as to be relatively rotatable.

The A-system driven gear 25 has the same number of teeth as the A-system drive gear 23, and is rotatably fitted and supported on the B-system rotary shaft 22. Similarly, among a pair of gears of the B system having the same number of teeth, the B system drive gear 34 is fixed to the B system rotation shaft 22 so as not to rotate, and the B system driven gear 31 is connected to the A system rotation shaft 21. And are rotatably fitted to and supported by. The A-system fixed eccentric weight 26 cannot rotate relative to the A-system rotation shaft 21,
The B-system movable eccentric weight 27 is fitted and supported so as to be relatively rotatable, and the B-system movable eccentric weight 27 is connected to the B-system driven gear 31 by the synchronous connecting rod 3.
3 and are connected together and rotate together. As a result, the B-system movable eccentric weight 27 is rotated at the same rotational speed in the direction opposite to the B-system rotating shaft 22. The B-system fixed eccentric weight 28 is fitted to and supported by the B-system rotating shaft 22 so that the B-system fixed eccentric weight 28 cannot rotate relatively and the A-system movable eccentric weight 29 can rotate relatively. The A-system movable eccentric weight 29 is integrally connected to the A-system driven gear 25 via a synchronous connection rod 30 and rotates together. As a result, the A-system movable eccentric weight 29 is rotated at the same rotational speed in the direction opposite to the A-system rotating shaft 21. The A-system driven pulley 35 is attached to the A-system rotating shaft 21.
Is fixed, and the A-system drive pulley 38 is fixed to the A-system drive motor Ma, and the wrapping transmission means 37 is wound around the A-system driven pulley 35 and the A-system drive pulley 38 to transmit power. I have. A B-system driven pulley 36 is fixed to the B-system rotating shaft 22, and a B-system drive pulley 39 is fixed to the B-system drive motor Mb.
Then, the wrapping transmission means 37 is wrapped and transmitted.
FIG. 2 is a horizontal cross-sectional view of the vibration exciter according to the embodiment shown in FIG. 1, which has the same outlines, symbols, and names of members as those in FIG. 1. Rotational members of the B system are indicated by parallel diagonal lines and spots are added to indicate system divisions and transmission paths.

Although not shown, the A-system rotating member and B
Allowing a phase difference within a predetermined angle range with the rotating member of the system,
Mutual rotation is restricted. The relative rotation between the A and B systems means an increase or decrease in the rotational phase difference between the A and B systems. In practicing the present invention, the means for restricting the rotation, that is, the means for limiting the phase difference can be set arbitrarily, but the fixed eccentric weight (26) fitted on the same rotating shaft (for example, reference numeral 21) can be used. Conveniently, a part and a part of the movable eccentric weight (27) are configured to contact with play. This type of technique is disclosed, for example, in the specification and drawings of Japanese Patent Application No. 7-159479.

In this embodiment, the phase difference limiting range between the A-system eccentric weight and the B-system eccentric weight is set as follows. B
When the system drive motor Mb is operated to rotate the B-system rotation shaft 22, the B-system rotating member indicated by spots in FIG. 2 rotates. Since the rotating members of the A system indicated by the parallel diagonal lines cannot be delayed from the B system, the rotating members rotate together with the shape pushed by the B system by a smaller angle than the B system. This state is a state close to the reference state where the eccentric moments of both the A and B systems become zero. However, the eccentric moment is not completely set to zero, and the gravitational acceleration g
The minute angle is set so as to generate a vibration acceleration substantially equal to. The value of the phase difference appropriate for causing the vibration acceleration substantially equal to the gravitational acceleration can be obtained by calculation, but it is also easy to obtain the value by experimentally measuring the actual machine. Further, when the A-system drive motor Ma is operated, the rotating member of the A-system is rotated, and the B-system, which cannot be delayed more than a predetermined angle from the A-system, is pulled by the A-system to have an allowable angle range. Rotate together with a delay of the maximum phase difference angle (when rotating together, A, B
Both systems have the same rotation speed). This state is set so that the phase difference is reduced by about 30 degrees as compared with the reference state in which the phase difference between the A and B systems is 180 degrees. The reason is that, when the phase difference is rotating in a state smaller than 180 degrees−30 degrees = 150 degrees, an extremely large operation force is required to return the phase difference to the standard state. is there. According to tests conducted by the present inventors, it is most convenient to set the phase difference from the reference state to about 30 degrees.

In order to perform a pile driving operation using the apparatus of this embodiment, (see also FIG. 5)
The B-system drive motor Mb is operated to start rotating with the minimum eccentric moment (minimum vibrating force, vibration acceleration about g), while increasing the number of rotations as indicated by the arrow c, the ground-specific ground motion number n ₁ and the crane It passes through the boom natural frequency n ₂ with the minimum eccentric moment. When the passage is completed, the energization of the B-system drive motor Mb is cut off or the energization is reduced, and A
The system drive motor Ma is operated. In this case, the rotation frequency (rotation speed) of the eccentric weight is equal to the vibration frequency of the generated vibration. When the rotation speed reaches the rated rotation speed (point i), the operation shifts to a steady operation. In this state, the system A is advanced by about 30 degrees from the reference state to become the maximum eccentric moment, and performs the pile driving work while exhibiting the maximum vibration force. This steady operation is A
The system pulls the system B, and the system B follows with a delay of about 30 degrees. During this steady state operation period, the B-system drive motor Mb may be de-energized. In addition, B system is A
Electric energy may be supplied to the B-system drive motor Mb to such an extent that it cannot catch up with the system. When the pile driving operation is completed (point j), the drive motors Ma and Mb of both the A and B systems
Is stopped, and electric braking is applied to the A-system drive motor Ma. As a result, the eccentric moment is minimized, and sequentially passes through the crane boom natural frequency n ₂ and the ground natural frequency n ₁ , decelerates as indicated by an arrow m, and stops (point m).

FIG. 3 is a horizontal sectional view schematically showing an embodiment different from the embodiments shown in FIGS. 1 and 2 described above. The differences from the above embodiment are as follows. The A-system drive gear 40 fixed to the A-system drive motor Ma is meshed with the A-system drive gear 23, and the B-system drive gear 41 fixed to the B-system drive motor Mb is meshed with the B-system drive gear 34. According to the present embodiment (FIG. 3), there is an advantage that the lateral width L of the device is smaller than that of the embodiment (FIGS. 1 and 2). However, the embodiment (FIGS. 1 and 2) has an advantage that the gear noise is small.

[0022]

When the present invention is applied to the control of an exciter composed of a fixed eccentric weight and a movable eccentric weight, the fixed eccentric weight of the A system and the movable eccentric weight of the A system are always in a fixed position. Difference (1
80 degrees), and the fixed phase difference between the fixed eccentric weight of the B system and the movable eccentric weight of the B system is always constant (180 degrees).
), And the phase difference between the fixed and movable eccentric weights of the system A and the fixed and movable eccentric weights of the system B is constrained to be within a predetermined angle range. Therefore, A
When the fixed and movable eccentric weights of the system A are rotationally driven by the drive motor of the system, the fixed and movable eccentric weights of the system B cannot be delayed more than a predetermined angle from the system A, and the weights of the fixed and movable eccentric weights of the system B are within a predetermined angle range. Only after a delay (in the form of being pulled by the A system) it rotates in the same direction and operates at the maximum eccentric moment, generating the maximum vibrating force. Further, when the fixed and movable eccentric weights of the B system are driven to rotate by the drive motor of the B system, the phase cannot be advanced beyond a predetermined angle than the B system.
Both the fixed and movable eccentric weights of the system advance by the minimum angle within the predetermined angle range (in a form pushed by the system B), rotate in the same direction at the same rotational speed as the system B, operate in the state of the minimum eccentric moment, Generate minimum vibration force. To summarize the above operation, without detecting the rotational phases of the A and B systems or performing servo control, and without interrupting the operation of the vibration exciter, one of the two drive motors is used. By a simple operation of which one causes the exciter to be rotationally driven, it is possible to arbitrarily select any one of a state in which the maximum vibration is generated and a state in which the minimum vibration is generated.

[Brief description of the drawings]

FIG. 1 schematically shows an exciter provided with an embodiment of an eccentric weight excitatory force control mechanism biased to the present invention configured to carry out an excitatory force control method of the present invention. It is a horizontal sectional view.

FIG. 2 is a horizontal cross-sectional view of the vibration exciter according to the embodiment shown in FIG. 1 described above, in which the outlines, symbols and names of members are the same as those in FIG. Rotational members of the B system are indicated by parallel diagonal lines and spots are added to indicate system divisions and transmission paths.

FIG. 3 is a schematic cross-sectional view showing an embodiment different from the embodiments of FIGS. 1 and 2 described above.

FIG. 4 is an explanatory diagram showing transmission of ground waves and underground waves in a pile driving work using a vibration device.

FIG. 5 is a table showing time-rotation speed for explaining a resonance phenomenon in a vibrating pile driving work.

FIG. 6 is a view for explaining a known technique for changing a vibrating force by a combination of two eccentric weights, in which (A) shows that two eccentric weights generate a maximum vibrating force; (B) is a schematic diagram showing a state in which the vibrating force is moderate, (C) is a schematic diagram showing a state in which the vibrating force is slightly small, and (D) is a schematic diagram showing a state in which the vibrating force is zero. It is a schematic diagram showing a state.

FIG. 7 is a schematic diagram of a mechanism in which a fixed eccentric weight is fixed to a common rotation shaft and a movable eccentric weight can adjust a relative rotation angle position with respect to the common rotation shaft.

FIG. 8 shows a fixed eccentric weight and a movable eccentric weight arranged on a common axis so as to be able to increase and decrease the vibrating force as shown in FIG. It is a perspective view which shows the conventional example of a shaker.

FIG. 9 is a view for explaining the relationship between the rotating shaft, the fixed eccentric weight, and the movable eccentric weight in the conventional exciter having the adjusting mechanism shown in FIG. 1) is an external perspective view partially cut and drawn, and FIG. 2B is a schematic view illustrating a portion viewed in a direction parallel to the rotation axis.

[Explanation of symbols]

1: Exciter case, 2, 2A to 2D: Rotating shaft, 3, 3
A to 3D: eccentric weight, 4, 4A to 4D: transmission gear for synchronous transmission, 5: crane boom, 6: vibration device (exciter), 7: pile, 8: private house, 9, 9A, 9B ... Fixed eccentric weight, 10, 10A, 10B ... movable eccentric weight, 10a-1
0c: Adjustable position of movable eccentric weight, 11: Drive pulley,
12: female screw hole, 13: knock pin, 14: set bolt, 15: hexagon wrench, 21: rotary shaft of A system, 22: B
System rotating shaft, 26 ... A system fixed eccentric weight, 27 ... B system movable eccentric weight, 28 ... B system fixed eccentric weight, 29 ... A system movable eccentric weight, Ma ... A system drive motor, Mb ... B System drive motor.

Claims (14)

(57) [Claims] An eccentric weight rotation drive system of system A and an eccentric weight rotation drive system of system B are provided, and an A system fixed eccentric weight (26) is fixed to an A system rotation shaft (21). The B-system movable eccentric weight (27) is attached to the A-system rotating shaft so as to be relatively rotatable, and the B-system fixed eccentric weight (28) is fixed to the B-system rotating shaft (22). The A-system movable eccentric weight (29) is attached to the rotating shaft so as to be relatively rotatable, and the A-system fixed eccentric weight (26) and the A-system movable eccentric weight (29) are always rotated at the same rotational speed in opposite directions. And the B-system fixed eccentric weight (28) and the B-system movable eccentric weight (27) are interlocked so as to always rotate in the opposite direction at the same rotation speed; The phase difference between the rotation phase of the system and the rotation phase of the system B is 0 degree or more. The rotating members of the two systems are mechanically constrained so as not to exceed a predetermined angle range of 80 degrees or less, and the A system rotating shaft (21) and the B system rotating shaft (22) are separately controlled. A method for controlling the vibrating force of an eccentric weight, characterized in that it is driven to rotate by a motor capable of being driven. 2. An A-system drive gear (23) fixed to the A-system rotation shaft (21), and an A-system driven gear (25) rotatably mounted on the B-system rotation shaft (22). And the A-system driven gear and the A-system movable eccentric weight (29) are non-rotatably connected to each other, and the B-system drive gear (34) fixed to the B-system rotation shaft (22). And a B-system driven gear (31) rotatably attached to the A-system rotation shaft (21), and the B-system driven gear and the B-system movable eccentric weight (27)
2. The method according to claim 1, wherein the eccentric weight and the eccentric weight are connected to each other so that they cannot rotate relative to each other. An A-system driven pulley (35) is fixed to the A-system rotating shaft (21), and a winding transmission is performed by an A-system driving motor (Ma) to which an A-system drive pulley (38) is attached. A driving pulley (39) on the B-system rotating shaft (22) through the means (37);
And driven by a B-system drive motor (Mb) to which a B-system drive pulley (39) is attached via a winding transmission means (37).
An eccentric weight excitation force control method according to claim 2. 4. An A-system driving gear (40) attached to an A-system driving motor (Ma) is connected to an A-system rotating shaft (21).
Meshed with the A-system drive gear (23) fixed to
The rotating member of the system is rotationally driven, and the B system driving gear (41) attached to the B system driving motor (Mb) is engaged with the B system driving gear (34) fixed to the B system rotating shaft (22). 3. The method for controlling the vibrating force of an eccentric weight according to claim 2, wherein the rotating member of the B system is driven to rotate. 5. The eccentric weight according to claim 1, wherein a maximum value of the predetermined angle range from 0 to 180 degrees is set as follows. Exciting force control method. A system fixed eccentric weight (26) and B
When the system movable eccentric weight (27) is positioned symmetrically with respect to the system A rotation axis (21), the system B fixed eccentric weight (2)
8) and the A-system drive gear (23) and the A-system driven gear (25) such that the A-system movable eccentric weight (29) is symmetrically positioned with respect to the B-system rotation axis (22).
And the B-system drive gear (3
4) and the B-system driven gear (31) are set in meshing relationship, and assuming a state where the total eccentric moment when these four eccentric weights are rotated becomes zero, this is defined as A, B. The rotation phase difference between the two systems is defined as 180 degrees, and the rotation phase difference between the A and B systems is about 180 degrees, and the vibration acceleration generated by the rotation of the four eccentric weights is substantially equal to the gravitational acceleration. An angle corresponding to the equal phase difference is defined as the maximum value in the predetermined angle range. 6. The method according to claim 5, wherein the minimum value in the predetermined angle range from 0 ° to 180 ° is set as follows. The state where the rotation phase difference is 180 degrees is set as a reference state, and the rotation phase difference is set to be smaller than the reference state by about 30 degrees. 7. A pile driving operation in which the phase difference between the rotation phase of the system A and the rotation phase of the system B is set to a maximum value within a predetermined angle range to minimize the total eccentric moment of the four eccentric weights. The rotation speed of the A system and the rotation speed of the B system pass through the rotation speed corresponding to the natural frequency of the ground at the pile driving work site and the rotation speed corresponding to the natural frequency of the crane boom for the pile driving operation. After that, the phase difference between the rotation phase of the A-system and the rotation phase of the B-system is set to the minimum value within a predetermined angle range, and the total eccentric moment of the four eccentric weights is maximized to perform steady operation. The method according to claim 1, wherein the state shifts to a state. 8. A phase difference between the rotation phase of the A-system and the rotation phase of the B-system as a minimum value within a predetermined angle range.
After performing the steady operation by maximizing the total eccentric moment of the four eccentric weights, minimizing the total eccentric moment of the four eccentric weights by setting the phase difference to a maximum value within a predetermined angle range. 8. The method according to claim 7, wherein the rotational speeds of both the A and B systems are reduced to stop the system. 9. An eccentric weight of system A and its rotary drive system, an eccentric weight of system B and its rotary drive system, and an A system fixed eccentric weight (26) on the A system rotating shaft (21). Is fixed, and a B-system movable eccentric weight (27) is rotatably fitted to the A-system rotation shaft, and a B-system fixed eccentric weight (28) is fitted to the B-system rotation shaft (22). The A-system movable eccentric weight (29) is fixed to the B-system rotating shaft so as to be relatively rotatable. The A-system fixed eccentric weight (26) and the A-system movable eccentric weight (29) ) Is always provided in the opposite direction at the same rotational speed, and the B-system fixed eccentric weight (28) and the B-system movable eccentric weight (27) are always rotated in the opposite direction at the same rotational speed. Interlocking means for rotating is provided, and A mechanical means is provided for restraining the phase difference between the rotation phase and the rotation phase of the B system within a predetermined angle range of 0 degree or more and 180 degrees or less, and A for rotating and driving the A system rotation shaft (21). A system drive motor (Ma) and a B system drive motor (Mb) for rotating and driving the B system rotation shaft (22) are provided, and the A and B drive motors (Ma, Mb) are individually controlled. A vibrating force control mechanism for an eccentric weight, characterized in that it can be driven. 10. An A-system drive gear (23) and an A-system driven gear (25) having the same number of teeth, and a B-system drive gear (34) and a B-system drive gear having the same number of teeth.
A system driven gear (31), an A system drive gear (23) is fixed to the A system rotation shaft (21), and an A system driven gear (25) is the A system drive gear (23).
And is integrally connected to the A-system movable eccentric weight (29) so as to be rotatable relative to the B-system rotating shaft (22), and is connected to the B-system movable eccentric weight (29). (31) The B-system drive gear (34)
And is fitted so as to be relatively rotatable with the A-system rotating shaft (21), and is integrally connected to the B-system movable eccentric weight (27). An eccentric weight vibrating force control mechanism according to claim 9. 11. An A-system driving motor (M) having an A-system driven pulley (35) fixed to the A-system rotating shaft (21) and having an A-system driving pulley (38) attached thereto.
a) is driven to rotate via the wrapping transmission means (37), and the B-system driven pulley (39) is attached to the B-system rotation shaft (22).
And a rotary drive via a winding transmission means (37) by a B-system drive motor (Mb) to which a B-system drive pulley (39) is attached. The oscillating force control mechanism for an eccentric weight according to claim 10. 12. An A-system driving gear (40) attached to an A-system driving motor (Na) includes an A-system rotating shaft (2).
The B-system drive gear (41), which is engaged with the A-system drive gear (23) fixed to 1) and is attached to the B-system drive motor (Mb), is fixed to the B-system rotary shaft (22). B
A system drive gear (34) meshes with the A system drive motor (Ma) and the B system drive motor (Mb) so that they can be independently controlled. An eccentric weight vibrating force control mechanism according to claim 10. 13. When the rotational phase difference between the eccentric weight of the system A and the eccentric weight of the system B has a maximum value, the total eccentric moment of these eccentric weights has a minimum value, and The eccentric weight according to claim 9, wherein a vibration acceleration of a vibration generated when the eccentric weight rotates at a rated rotation speed in a minimum state is configured to be substantially equal to a gravitational acceleration. Vibration force control mechanism of the weight. 14. A minimum value in a predetermined angle range regarding a phase difference between the rotation phase of the A-system and the rotation phase of the B-system is 180 degrees when the fixed eccentric weight and the movable eccentric weight are symmetrically positioned with respect to the rotation axis. 10. A virtual state having a phase difference of the reference state is set as a reference state, and is set to a value smaller by about 30 degrees than the phase difference in the reference state.
The vibration force control mechanism of the eccentric weight described in [1].