JP3243551B2 - Exciting force control method for exciter and exciting force control device for exciter - 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 may be started while giving a slight vibration, 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 and stopping the operation of the vibration device. The horizontal axis represents time.

[0006] From operation start time point 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 n of the ground
₁ and the natural frequency n ₂ of the crane boom. 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, not a serious problem Was. 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, gradually as indicated by an arrow d in Naka continues to rotate at a rotational axis of inertia Slow down. Since the rotational speed decrease period T ₂ of the above is relatively long (e.g. about 50 seconds),
When passing the natural frequency n ₂ of the crane boom on the way, the crane boom may resonate and suffer damage. 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 the 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, if the vibrating device starts the operation with the oscillating force changed to zero by changing the rotation phase of the eccentric weight, and if the oscillating 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 rotation energy in the rotating member, and the operation can be continued by replenishing the energy enough to compensate for the vibration damping.

[0008] 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 in which 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 standard state. FIGS. 6 (B) and 6 (C) are intermediate states of the above (A) and (B), respectively, so that the vertical vibrating force is smaller than the case of FIG. 6 (A) and larger than that of FIG. Occurs. (B) is closer to the state of FIG. (A) than FIG. (C), so that (A), (B), (C), and (D) are listed in descending order of the vibrating force. Becomes In order to show the principle of the vibrating force increase / decrease control in FIG. 6, the two rotating shafts 2B 'and 2C' are connected to the synchronous rotating gears 4B 'and 4C'.
Although it is drawn to rotate synchronously, two eccentric weights can be arranged on one rotating shaft in order 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).
From this state, when the movable eccentric weight is rotated and fixed in the direction of the arrow α, the vibrating force decreases as it 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 bolt, the movable eccentric weight takes three angular positions as shown in FIG.
The vibrating force is changed by relatively rotating as shown by b and 10c. The exciter according to the related art shown in FIGS.
As described above, it is possible to adjust the increase and decrease of the vibrating force.

[0011]

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.
A lot of time and labor is required to lift the crane boom 5 again and attach it to the upper end of the pile 7.
As shown in FIG. 10, a fixed eccentric weight and a movable eccentric weight are attached to a single rotation center axis, and furthermore, it is possible to continuously increase or decrease the vibrating force without stopping the operation. The configuration is valid.

Known invention (Japanese Patent Application No. 7-236695)
Hereinafter, the invention is referred to as a prior invention.

FIG. 10 shows a vibration exciter provided with an embodiment of a vibration force control mechanism for an eccentric weight according to the invention of the prior application which is configured to carry out the vibration control method of the invention of the prior application. FIG. 2 is a horizontal sectional view schematically shown. Depending on the case 1, two horizontal axes, that is, the A-system rotation shaft 21 and the B-system rotation shaft 2
2 are rotatably supported. An A-system drive gear 23 is fixed to the A-system rotary shaft 21 via a key 24. In FIG. 10, seven keys are drawn.
Although only one symbol is attached, the drawing of the key indicates that the key is fitted so that it cannot rotate relative to the rotation axis. 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 via a synchronous connection rod 33. They 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. Said B
The B-system fixed eccentric weight 28 is fitted to and supported by the B-system fixed eccentric weight 28 so as to be relatively non-rotatable, and the A-system movable eccentric weight 29 is relatively rotatable with respect to the system rotation shaft 22. 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. Thereby, the A-system movable eccentric weight 29 becomes
It is rotated at the same rotation speed in the direction opposite to the A-system rotation shaft 21.

An A-system driven pulley 35 is fixed to the A-system rotary shaft 21 and an A-system drive motor Ma
A system drive pulley 38 is fixed, and a winding transmission means 37 is wound around the A system driven pulley 35 and the A system pulley 38 for transmission. A B-system driven pulley 36 is fixed to the B-system rotating shaft 22, and a B-system driving pulley 39 is fixed to the B-system driving motor Mb.
Then, the wrapping transmission means 37 is wrapped and transmitted.

In order to perform a stakeout operation by using the apparatus shown in FIG. 10, at the operation start point O (see also FIG. 5),
By operating the B-system drive motor Mb, it starts rotating with the minimum eccentric moment (minimum vibrating force, vibration acceleration about g), and while increasing the rotation speed as indicated by arrow c, the ground natural frequency 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 number of rotations (rotational speed) of the eccentric weight is equal to the number of starting vibrations to be generated. When the rotation speed reaches the rated rotation speed (point i), the operation shifts to a steady operation. In this state, the A-system advances the phase by a certain angle from the reference state to become the maximum eccentric moment, and performs the pile driving operation while generating the maximum vibrating force. This steady operation is A
In the form in which the system pulls the system B, the system B follows with a certain angle delay. 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 the system cannot catch up. 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 d, and stops (point m).

After applying for the invention of the prior application shown in FIG. 10 described above, the inventor of the present invention carried out industrial production of the invention and continued to carry out further improvement studies, especially practical use tests, and as a result, It has been confirmed that the present invention has a desired effect under practical conditions and contributes to the prevention of vibration pollution, and that there is still room for improvement. That is, (a) the fixed eccentric weight, the gear for synchronously rotating the weight, the movable eccentric weight, and the gear for synchronously rotating the weight are separate components, so that the number of components is large, and (b) For similar reasons, the width dimension of the device W ₁
There is a limit to the reduction of the size, and (c) the assembling work of the apparatus is poor for the same reason, and the assembling work requires a high level of skill and a great deal of labor.

Improving the disadvantages of the above items a, b and c,
With a small number of components, to construct a compact and good assembling work exciter with variable total eccentric moment,
The structure shown in FIG. 11 is effective. This technique is an unknown invention (Japanese Patent Application No. 8-10) filed by the present inventors and separately filed.
No. 9545), which is hereinafter referred to as an unknown improved invention.

FIG. 11 shows an embodiment of a supporting structure for an eccentric weight according to the present invention, which disassembles a fixed eccentric weight and a movable eccentric weight and supports these eccentric weights. It is the perspective view which bent center line XX of the eccentric weight gear shaft by angle (phi) around the Z-axis, and fractured and drawn a part. The fixed eccentric weight gear 16, its gear boss 19, and the fixed eccentric weight 9 are integrally connected to each other to form a fixed eccentric weight block. On the other hand, the movable eccentric weight gear 17, its gear boss 19 'and the movable eccentric weight gear 17 are integrally connected to form a movable eccentric weight block.

As shown in FIG. 11, the gear boss 1
Reference numerals 9 and 19 'each have a length L and a radius r. The fixed eccentric weight 9 and the movable eccentric weight 10
Have the same shape and the same size, and both have a "shape obtained by vertically dividing a thick cylinder having a length 2L and an inner diameter 2r". Here, the vertical division refers to a shape cut by a plane passing through the center line, but is not a bisecting portion but a portion smaller than 1/2 of the cylinder. That is, the apex angle θ of the shape similar to the fan shape that appears in the cross section is set to 180 degrees−30 degrees = 150 degrees. The gear boss 19 has a length dimension set to L and a radius dimension set to r. That is, a cylindrical surface that forms the outer periphery of the gear boss 19,
The cylindrical surface forming the inner periphery of the fixed eccentric weight 9 is the same cylindrical surface. The fixed eccentric weight gear 16, the gear boss 19, and the fixed eccentric weight 9 are closely attached to each other and are integrally connected. Although not shown, these members may be formed separately and then adhered to each other and fixed. Like the fixed eccentric weight block described above, the movable eccentric weight 10
The movable eccentric weight gear 17 and the gear boss 19 'are integrally connected to each other to form a movable eccentric weight block.

By combining the above-described eccentric weight according to the present invention with an improved invention and known phase adjusting means, it is possible to control the eccentric moment of the fixed eccentric weight and the movable eccentric weight.

The vibration exciter according to the invention of the prior application shown in FIG. 10 has an excellent practical effect that the vibration can be controlled to increase or decrease by changing the total eccentric moment while continuing without stopping the operation. Although it has the excellent function performed, it has a disadvantage that the control mechanism is complicated because the two motors Ma and Mb have to be interlocked and controlled. FIG.
The structure of the vibration exciter according to the unknown improved invention shown in FIG. 1 is that the minimum unit of the vibration generating mechanism composed of the fixed eccentric weight and the movable eccentric weight (this is called a vibration generating unit) is compact. However, in order to put this to practical use, it is necessary to provide a phase adjusting means (specifically, a means for adjusting the phase difference between the two) between the fixed eccentric weight and the movable eccentric weight. Various types of phase adjusting means have been developed and are known, but a phase adjusting means is interposed between a fixed eccentric weight and a movable eccentric weight which are housed in a casing and operate. Then, it becomes very difficult to maintain the phase adjusting means from outside the casing. In particular, it is extremely difficult to replace parts of the phase adjusting means from outside the casing, and it is impossible to replace the assembly of the phase adjusting means. The present invention has been made in view of the above-mentioned circumstances, and the above-mentioned previously unknown invention (FIG. 10)
In addition to integrating the technical ideas that constitute the above-mentioned unknown improved invention and further improving it, it is excellent in maintainability, and it is possible to replace parts and assemblies of the phase adjustment mechanism part and control An object of the present invention is to provide a method for controlling a vibrating force of a vibrator, which has a simple mechanism and high operation reliability, and a device suitable for carrying out the method of the invention.

[0023]

[0024]

In order to achieve the above object,
The method according to the first aspect of the present invention is a method according to the first aspect of the present invention, wherein a pair of rotating shafts rotatably supported on a casing, and a pair of rotating shafts housed in the casing and rotated synchronously with each of the pair of rotating shafts. A vibration exciter comprising a pair of eccentric weights and a driving means for rotating the rotating shaft, wherein at least one of the pair of rotating shafts is formed in a tubular shape, and the pair of rotating shafts is formed. The other is inserted into the tubular shaft to form a concentric double shaft. The double shaft configured as described above is extended to project outside the casing, and the double shaft of the portion projecting from the casing is operated. Exciting force of a method in which the phase difference between the pair of rotating shafts is increased or decreased by rotating the force relatively.
A control method, comprising: moving an inner shaft from one end of an outer tube of the double shaft.
The part where the inner shaft protrudes from the outer tube
If there is a spiral groove or spiral ridge, or a groove parallel to the axis
The outer tube near the end of the outer tube should be flat with the shaft center.
Groove or ridge, or spiral groove or ridge
Gently externally fit a cylindrical member to the end of the double shaft.
And a concave sliding portion on the inner peripheral surface of the cylindrical member.
Or a convex sliding portion, and the spiral groove or
Fit into a spiral ridge or a groove or ridge parallel to the axis
Align, reciprocating to the tubular member in the axial direction, the
Specially, the outer tube and the inner shaft of the double shaft are relatively rotated.
Sign. According to the method of the first aspect described above, since the fixed eccentric weight shaft and the movable knitting weight weight shaft form a double shaft, a penetrating point in the case where the shaft is extended to project outside the casing. Is sufficient in one place, the shaft is easily supported, and the fixed eccentric weight shaft and the movable knitting weight weight shaft protrude outside the casing, and an operation force is applied to the protrusion to control the phase difference. The mechanism for providing the operating force is necessarily located outside the casing, so that its maintenance is easy and the assembly can be replaced. Since the outer tube and the inner shaft of the double shaft are respectively attached to the movable knitting center weight or the movable knitting center weight, they are fixed by controlling the phase difference between the outer tube and the inner shaft of the double shaft. The eccentric weight and the movable knitting weight are subjected to phase difference control, and the total knitting moment of both eccentric weights changes. By changing the total eccentric moment, the excitation force can be reduced to zero without reducing the rotation speed, and the excitation force can be increased without increasing the rotation speed (or keeping the rotation speed constant). You can also. In particular, in the method of the present invention, the outer tube and the inner tube are used.
When a spiral groove or spiral ridge is provided on either one of the shaft
In both cases, either the outer tube or the inner shaft has a groove parallel to the axis.
Or, because a ridge is provided, the stroke dimension of the cylindrical member
The angle of change of the phase difference with respect to
You. In other words, the cylindrical portion for the desired phase difference adjustment angle
The axial movement amount of the material is approximately doubled. Instead, the tube
The force required for the reciprocating drive of the shaped member is reduced by about half,
The accuracy of the phase difference adjustment angle is approximately doubled. Therefore, the eccentric weight
The extendable dimension of the double shaft, which is the spindle, is relatively large and is cylindrical.
It is difficult to increase the driving force of the members
Fine control of increase / decrease of excitation force by change of heart moment
Suitable when control is desired.

[0025]

[0026]

[0027]

[0028]

[0029]

[0030]

According to a second aspect of the present invention, a pair of rotating shafts rotatably supported by the casing and the pair of rotating shafts respectively taken up by the pair of rotating shafts and housed in the casing. In a device for controlling the vibration force of a vibration generator having a pair of eccentric weights and a motor for rotationally driving the rotation and the eccentric weights, the pair of rotation shafts may be an outer tube. And at least one end of the double shaft extends and protrudes out of the casing, and a portion where the double shaft protrudes out of the casing includes: have a phase difference increases or decreases adjusting the rotation phase difference between the inner and the outer tube axial adjustment provided, the tip portion of the inner shaft
Project from the tip of the outer tube, and the inner shaft
Helical groove or helical protrusion
A ridge is formed or a groove or axis parallel to the axis
Parallel ridges are formed and the outer tube is
Closely, a groove parallel to the axis or a ridge parallel to the axis,
Has a twisting direction in comparison with the spiral groove or spiral ridge.
Is formed with a spiral groove or spiral ridge on the opposite side.
And a cylindrical member is gently attached to the tip of the double shaft.
Externally attached to the inner peripheral portion of the cylindrical member,
A mated convex slide parallel to the groove or axis, or
Alternatively, the helical ridge or the ridge is formed in a groove parallel to the axis.
The fitted concave slip portion is formed, and the cylindrical
Reciprocate in the axial direction without hindering the rotation of the members
Characterized in that it is provided with a driving means . According to the apparatus of the second aspect described above, the pair of rotating shafts attached to the pair of eccentric weights constituting the vibration exciter project outside the casing in a double shaft shape. Therefore, there is only one place where the rotating shaft passes through the casing wall, and the supporting of the rotating shaft is easy. In addition, when sealing of the penetrating portion is required, the sealing structure is simple and sufficient. Since the means for increasing or decreasing the rotational phase difference is provided at the portion where the double shaft protrudes out of the casing, the rotational phase difference increasing / decreasing adjusting means can be inspected and serviced without any hindrance by the casing, and parts can be replaced. It can be repaired, and the assembly of the phase difference increase / decrease adjusting means can be replaced. The number of man-hours required for assembling a control mechanism when producing an exciter including an exciter adjusting device is small, and the manufacturing cost is low. In particular, the invention device of claim 2
In this case, the outer tube and inner shaft are moved with the axial movement of the cylindrical member.
The exciter rotates relatively to keep the exciter running
Can be controlled to increase or decrease.
Either one does not rotate and only the other rotates
, So that it is smaller than the amount of axial movement of the cylindrical member.
Small phase change angle and easy fine control
And the required driving force is small. Therefore, the axis of the cylindrical member
Required driving force by increasing the reciprocating stroke dimension
This is suitable for reducing.

[0032]

[0033]

[0034]

[0035]

[0036]

[0037]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an embodiment of a vibrating force control device configured to carry out a vibrating force control method for a vibrator according to the present invention. It is sectional drawing of the exciter provided with one set of control apparatuses. As shown in the drawing to the left from the figure, a lead line, a code, and a name are provided.
And the double shaft 45 are supported in parallel and rotatably. The above-mentioned double shaft is named according to its structural characteristics, and is a shaft that supports the eccentric weight when viewed from its role. That is, the outer tube 45a forming a concentric double axis is fixed integrally with the control-side fixed eccentric weight 47, and the inner shaft 45b is fixed to and supported by the control-side movable eccentric weight 49. . In this embodiment, the two shafts (4
4, 45) to form two sets of vibrating units consisting of a fixed eccentric weight and a movable eccentric weight, one set of each of which is shown in FIG. 11 described above. The configuration is basically the same as that of an unknown improvement invention. In the vibrating unit illustrated in the upper part of the figure in FIG. 1, the eccentric weight gear shaft 44 is rotationally driven by the drive motor 50, so that the eccentric weight fixed to the eccentric weight gear shaft 44 is fixed. Acts as an eccentric weight, which is fixed to the drive side fixed eccentric weight 46.
Call. The eccentric weight that is rotatably fitted to the eccentric weight gear shaft 44 is referred to as a drive-side movable eccentric weight 48. The eccentric weights 47 and 49 are referred to as the control side in the opposite sense of the drive side.

The double shaft 45 extends outside the casing 43 (to the right in the figure), and the inner shaft 45b projects from the outer tube 45a. A spiral groove 54 is formed in this protruding portion, and a "reverse twisting spiral groove 55 having a twisting direction opposite to that of the spiral groove 54" is formed near the tip of the outer tube 45a. ing. The detailed structure of this part will be described later with reference to FIG. The name of the spiral groove 55 in the reverse torsion direction is for convenience of explanation, and there is no distinction as to which of the two spiral grooves is originally positive and which is essentially opposite. A tubular member 56 is loosely fitted into the spiral groove 54 and the reverse spiral direction spiral groove 55, and two convex portions formed inside the cylindrical member 56 form the two spiral threads. It is slidably fitted in each of the grooves. The structure of these parts will be described later in detail with reference to FIG. A member denoted by reference numeral 51 is a hydraulic cylinder that also serves as a cover that covers a phase difference control mechanism portion including the spiral grooves 54 and 55 and the cylindrical member 56. It is attached detachably. Reference numeral 52 denotes an annular piston, which does not include a piston rod, and the cylindrical member 56 is attached to the inside of the piston via a bearing 53.

FIG. 2 is a detailed cross-sectional view in which the vicinity of a phase difference control mechanism similar to that of the embodiment shown in FIG. 1 is enlarged and drawn. The outer tube 54a, the inner shaft 45b, the control-side fixed eccentric weight 47, the control-side movable eccentric weight 49, the cover / hydraulic cylinder 51, the annular piston 52, and the bearing 5 shown in FIG.
3 and the tubular member 56 are components described with reference to FIG. A spiral groove 54 is formed at a portion where the inner shaft 45b protrudes from the outer tube 45a, and a reverse spiral direction spiral groove 55 is formed near the tip of the outer tube 45a corresponding to this. Reference numeral 2 is a cross-sectional view, and the reverse torsion direction spiral groove 55 does not appear as a solid line or a broken line (hiding line), and is shown by a virtual line. If the outer tube 45a is drawn as an external view without cutting, the reverse torsion direction spiral groove 55 will appear as a solid line at the position indicated by the virtual line. Two convex sliding portions 58 are fixed inside the cylindrical member 56, and are slidably fitted to the spiral groove 54 and the reverse spiral groove 55, respectively, to form a sliding pair. Although not shown, in principle, the spiral groove (including reverse twist) can be replaced with a spiral ridge.
Protrusions are a little inconvenient for assembly, but not practically impossible. When a spiral ridge is used, the above-mentioned convex sliding portion 58 is used.
Instead, a concave slip portion (not shown) is provided to form a slip pair.

FIG. 3 is a detailed sectional view showing the vicinity of the phase difference adjusting mechanism in an embodiment different from FIG. 2 described above. A groove 59 parallel to the axis is provided instead of the spiral groove 55 in the reverse torsional direction in the embodiment (FIG. 2), and a slip pair is formed by fitting the groove 59 with the convex slip portion 58. The structure is similar or similar to that of FIG. 2). The above-mentioned slip pair can also be constituted by a ridge parallel to the axis and a concave slip portion (both not shown). Considering in principle the convenience and inconvenience of assembling and machine work, in the present invention, "a sliding pair consisting of a ridge and a concave sliding portion" and "a sliding pair consisting of a groove and a convex sliding portion" Is mechanically equivalent, and can be substituted or used together. Further, a spiral groove or a ridge is formed in one of the outer tube 45a and the inner shaft 45b, and a groove or a ridge parallel to the axis is formed in the other of the outer tube 45a and the inner shaft 45b. Can be provided. As described above, when one of the grooves is a groove or a ridge parallel to the axis, the “outer tube 45a and the outer tube 45a with respect to“ the amount of movement of the cylindrical member 56 in the axial direction ”are different from the embodiment of FIG. The ratio of the “angle of change in phase difference due to relative rotation with the inner shaft 45b” is reduced by about half, but the driving force required to move the cylindrical member 56 in the axial direction is reduced by almost half. Further, halving the angle ratio is advantageous for fine control.

(See FIG. 1.) Each of the two sets of vibration generating units provided in the present embodiment has a rotation axis, a rotation center of a fixed eccentric weight, and a movable eccentric weight on one center line. The vibrating force is variable by adjusting the phase difference with the center of rotation. With such a vibration generating unit, a large-capacity vibration generating facility can be easily configured by providing a plurality of sets (preferably an even number of sets) of the vibration generating units. By producing vibration units with various specifications at a specialized factory, it is possible to supply them at high quality and at a low price, which can contribute to the production of various vibrators (particularly, vibration type construction machines). When a plurality of sets of vibration generating units are provided as shown in FIG. 1, the fixed eccentric weights and the movable eccentric weights are rotated synchronously via synchronous transmission gears. In this embodiment, when the drive-side fixed eccentric weight 46 is rotated by the drive motor 50, the control-side fixed eccentric weight 47 is rotated synchronously. The control-side movable eccentric weight 49 is rotationally driven by the inner shaft 45b via the above-described phase difference adjusting mechanism, and the drive-side movable eccentric weight 48 is synchronously rotated by the control-side movable eccentric weight 49 by gear transmission. Can be
In this case, the drive-side movable eccentric weight 48 is supported by the drive-side gear shaft 44 and is located closer to the drive motor 50, but the drive-side movable eccentric weight 48 is attached to the eccentric weight gear shaft 44. The control side movable eccentric weight 4
9 is driven and rotated via a gear. As understood from the above-mentioned structural function, the pair of fixed eccentric weights 4
6, 47 are directly driven to rotate by a drive motor. Then, the pair of movable eccentric weights 49 and 48 are rotated (by providing a desired phase difference) by the phase difference adjusting mechanism.

The desired phase difference is adjusted by moving the cylindrical member 56 in the axial direction by the annular piston 52. The reason is that the outer tube 45a fixed to the fixed eccentric weight and the inner shaft 45b fixed to the movable eccentric weight are relatively rotated by the axial movement of the tubular member 56. It is.

The cover / hydraulic cylinder 51 is specifically a cover / hydraulic cylinder main body. In general, when a cylinder is referred to, the term refers to the entire cylinder device including the piston, and sometimes refers only to the cylindrical member excluding the internal components.In the present invention, in the case of confusion, the entire device is referred to as cylinder means. The cylindrical member is referred to as a cylinder main body to be distinguished. Since the cover / hydraulic cylinder 51 is detachably attached to the casing 43, the cover / hydraulic cylinder 51 can be easily removed from the casing 43 to inspect, care for, or repair the phase difference adjusting mechanism. Also, the assembly of the phase difference adjusting mechanism can be exchanged.

[0044]

As described above, the configuration and function of the embodiment of the present invention have been clarified. According to the method of the first aspect of the present invention, the fixed eccentric weight shaft and the movable knitting center weight shaft have two axes . Since it has a heavy shaft shape, only one penetration point is required when extending it and projecting it out of the casing, the shaft is easily supported, and the fixed eccentric weight shaft and the movable knitting weight shaft are separated. Since it protrudes outside the casing and the operation force is applied to the protruding portion to control the phase difference, the structural part for applying the operation force is inevitably located outside the casing, and its maintenance is easy and the assembly is easy. Exchange is also possible. Since the outer tube and the inner shaft of the double shaft are respectively attached to the movable knitting center weight or the movable knitting center weight, they are fixed by controlling the phase difference between the outer tube and the inner shaft of the double shaft. The eccentric weight and the movable knitting weight are subjected to phase difference control, and the total knitting moment of both eccentric weights changes.
By changing the total eccentric moment, the excitation force can be reduced to zero without reducing the rotation speed, and the excitation force can be increased without increasing the rotation speed (or keeping the rotation speed constant). You can also. In particular, the invention of claim 1
In the method, the cylindrical portion that is a driving source of the phase difference adjusting action is provided.
Small change angle of phase difference compared to material stroke size
Therefore, it is suitable for fine control, and
The driving force of the cylindrical member is small.

[0045]

[0046]

[0047]

According to the second aspect of the present invention, the pair of rotating shafts attached to each of the pair of eccentric weights forming the vibration exciter project out of the casing in a double shaft shape. Therefore, it is easy to support the rotating shaft. Since the means for adjusting the rotational phase difference is provided at the portion where the double shaft projects out of the casing, the rotational phase difference adjusting means can be inspected and repaired without being hindered by the casing. , And assembly conversion is also possible. In particular, in the device according to the second aspect of the present invention, the cylindrical member
The inner shaft and the outer tube rotate relatively with the axial movement of
To increase or decrease the vibratory force while continuing to operate the vibration exciter.
And either the outer tube or the inner shaft
It doesn't move, only one of them turns
The phase difference change angle is smaller than the axial movement amount of the cylindrical member.
Small size, easy fine control, required driving force
Is small. Therefore, the axial reciprocating strike of the cylindrical member
I want to increase the roke size and reduce the required driving force
It is suitable for the case.

[0049]

[Brief description of the drawings]

FIG. 1 shows an embodiment of a vibrating force control device configured to carry out a vibrating force control method for a vibrator according to the present invention;
It is sectional drawing of the exciter provided with two sets of vibration units and one set of control devices.

FIG. 2 is an enlarged detailed sectional view of the vicinity of a phase difference control mechanism in the embodiment shown in FIG. 1 described above.

FIG. 3 is a cross-sectional view showing the vicinity of a phase difference adjusting mechanism similar to the embodiment different from FIG. 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. () Is an external perspective view partially cut and drawn, and (B) is a schematic view illustrating a portion viewed parallel to the rotation axis.

FIG. 10 shows an exciter equipped with an embodiment of an eccentric weight vibrating force control device according to an embodiment of the prior application, which is configured to carry out the exciting force control method according to the prior application; FIG. 3 is a schematic horizontal sectional view.

FIG. 11 shows an embodiment of an eccentric weight supporting mechanism according to an unknown improved invention, in which a fixed eccentric weight and a movable eccentric weight are disassembled, and the eccentric weight supporting these eccentric weights is shown. It is the perspective view which bent center line XX of a bevel gear axis | shaft by angle (phi) about Z-axis, and fractured and drawn a part.

[Explanation of symbols]

43 ... casing, 44 ... eccentric weight gear shaft, 45 ... double shaft, 45a ... outer tube, 45b ... inner shaft, 46 ... drive side fixed eccentric weight, 47 ... control side fixed eccentric weight, 48 ... drive side Movable eccentric weight, 49 ... control-side movable eccentric weight, 50 ... drive motor, 51 ... cover / hydraulic cylinder, 52 ... annular piston, 54 ... spiral groove, 55 ... spiral groove in reverse torsion direction, 56 ...
Cylindrical member, 58: convex sliding portion.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-5-230833 (JP, A) JP-A-8-131952 (JP, A) JP-A-4-108913 (JP, A) 10991 (JP, Y1) (58) Field surveyed (Int. Cl. ⁷ , DB name) E02D 7/18 E02D 11/00 B06B 1/16

Claims (2)

(57) [Claims] And 1. A pair of rotatably supported to the casing rotating shaft, the eccentric weight of each pair is rotated synchronously axis of rotation of said pair is housed within the casing, the And a driving means for rotating a rotating shaft, wherein at least one of the pair of rotating shafts is formed in a tubular shape, and the other of the pair of rotating shafts is formed in the tubular shaft. To form a concentric double shaft, extend the double shaft configured as described above and project it out of the casing, and apply an operating force to the double shaft in a portion protruding from the casing to relatively rotate the double shaft. A vibrating force control method in which the phase difference between the pair of rotating shafts is increased or decreased by moving the inner shaft so that the inner shaft protrudes from one end of the outer tube of the double shaft. Spiral groove or spiral ridge on the part protruding from the pipe, Or, a groove or a ridge parallel to the axis is provided, and a groove or a ridge parallel to the axis, or a spiral groove or a spiral ridge is provided on the outer peripheral surface near the end of the outer tube. Part, a cylindrical member is loosely fitted to the outside, and a concave sliding portion or a convex sliding portion is formed on the inner peripheral surface of the cylindrical member, and the spiral groove or the spiral ridge, or the shaft is formed. The cylindrical member is fitted in a groove or a ridge parallel to the core, and the cylindrical member is reciprocated in the axial direction to relatively rotate the outer tube and the inner shaft of the double shaft. , The method of controlling the vibrating force of the vibrator. (2)Rotatably supported on the casing
A pair of rotating shafts, The cable is attached to each of the pair of rotating shafts, and
And a pair of eccentric weights housed in the
A motor for rotating and driving the shaft and the eccentric weight.
Device to increase or decrease the vibration force of the vibration generator The pair of rotating shafts is a concentric double consisting of an outer tube and an inner shaft.
It has an axial shape, At least one end of the double machine shaft extends outside the casing.
Protruding, At the part where the double shaft protrudes outside the casing,
Phase adjustment means for increasing or decreasing the rotational phase difference between the
Provided, The tip of the inner shaft projects from the tip of the outer tube, At the part where the inner shaft protrudes from the outer tube, a spiral groove
Or a spiral ridge is formed or parallel to the axis
Grooves or ridges parallel to the axis are formed, A groove or axis parallel to the axis near the tip of the outer tube.
A ridge parallel to the helical groove or helical protrusion
Spiral groove or helical protrusion whose twisting direction is opposite to that of the ridge
Articles are formed, In addition, a cylindrical member is gently fitted to the tip of the double shaft.
The spiral groove is also provided on the inner peripheral portion of the cylindrical member.
Or a convex sliding part fitted in a groove parallel to the axis, or
Or fits into the spiral ridge or the ridge parallel to the axis
Formed concave slip part, Reciprocating in the axial direction without hindering rotation of the cylindrical member
Having driving means for moving Characterized by
Exciting force control device of exciter.