JP3044240B2 - Pile driver - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pile driving device for driving a pile into or pulling out a pile from soil by vibrating a vibrating cylinder which generates mechanical vibration by using a liquid pressure as an energy source. The present invention relates to a pile driving device suitable for driving and pulling out a ready-made concrete pile.

[0002]

2. Description of the Related Art Conventionally, methods of placing steel pipe piles or ready-made concrete piles of this type are roughly divided into hitting methods,
There are the auger combined hitting method and the embedding method. The striking method is a method in which a pile is driven from the beginning only by striking with a hammer such as a diesel hammer or a hydraulic hammer. The striking method using an auger involves drilling a pile hole in advance using a drill called an earth auger (spiral auger), This is a method in which only the supporting part is driven into the soil by hitting. The embedding method is a method in which a pile is inserted into a pile hole previously drilled by an earth auger and the surroundings are solidified by injecting concrete milk.

[0003]

In the conventional pile driving method, when a hole is previously drilled in the ground by an earth auger, the advantage is that the driving can be performed with a relatively small force and the operation can be performed relatively quietly. However, there is a decisive disadvantage that the work efficiency is extremely low because it requires digging with an earth auger, and the vibration generated at the time of driving the pile spreads to the surroundings without damping for a relatively long time,
There is a drawback that causes the so-called vibration pollution, which weakens the foundations of nearby buildings. In the case of the embedding method, although the problem of noise and vibration is reduced, concrete milk is mixed into the soil, so that the surrounding soil is treated as so-called industrial waste, and there is a problem in this treatment.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and is an apparatus capable of driving a pile into and out of the pile, specifically, a leader guide fixed and held in an upright state. A mounting frame slidably provided along the mounting frame; a traction force applying device provided on the mounting frame to apply traction force in both upward and downward directions along the leader guide to the mounting frame; and supported by the mounting frame via a cushion rubber. A vibration cylinder, a reaction weight provided above the vibration cylinder in the axial direction, and a reaction weight provided on the opposite side to the reaction weight with respect to the axial direction, so that the pile to be driven has its axis coincident with the axis of the vibration cylinder. Chuck means for gripping the vibration cylinder, an electric / hydraulic servo valve for driving and controlling the vibration cylinder, and the vibration cylinder by the electric / hydraulic servo valve. A piling device and a servo control system for controlling the. The present invention also excludes the aforementioned traction applying device in the aforementioned pile driving device, and
It is a pile driving device that can be operated without applying downward traction force. Further, the present invention is a pile driving device in which the mounting frame is simply suspended and the leader guide for slidably supporting the mounting frame is omitted in the pile driving device.

[0005]

[Function] A large pile driving force is obtained in combination with the alternating excitation force applied to the pile by the vibration cylinder, and the alternating excitation force by the vibration cylinder acts even when the pile is pulled out, so that a large pulling force can be given. Driving and pulling out piles can be performed efficiently. In devices with a traction device, the additional force thereby drives the stakeout and facilitates withdrawal.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS. In FIG. 1, reference numeral 1 denotes a hollow column-shaped mounting frame, which is slidably provided on a leader guide 11 which is held and fixed substantially vertically by a leader guide holding wheel 17 described later. The attachment frame 1 is always suspended from a top end of the leader guide 11 by a hanging rope 14 (FIG. 5).
From the suspension plate 12 attached to the lower end of the
A traction force applying wire 15 is connected to apply a traction force in both upward and downward directions along the leader guide 11 while being hung by the guide guide 11. The base end of the traction force applying wire 15 is wound around a drum of a winch 18 on a leader guide holding wheel 17, and its tip is wound around a guide roller 16 (FIG. 5) located below the pile K when driving the pile K. After that, it is connected to the lower part of the mounting frame 1. When the stake K is pulled out, the stake K is wrapped around a guide roller 19 (FIG. 6) located at the upper end of the leader guide 11 and then connected to the upper portion of the mounting frame 1. The mounting frame 1 may be extended upward to omit the suspension plate 12 and the suspension wires 13, and the mounting frame 1 may be directly suspended by the suspension ropes 14.

A base plate 3A is mounted on the inside of the mounting arm 1 via a buffer rubber 3, and a vibration cylinder 4 is provided on the base plate 3A with the piston 41 extending downward. A chuck means 6 for holding a pile K to be driven is fixed to the lower end of the piston 41 via a base plate 3A. Piston 41
Is more clearly shown in FIG.
The opposite side of the chuck means 6 with respect to the axial direction of the vibrating cylinder 4, that is, in this embodiment,
Is fixed. What is important here is that the chuck means 6 is provided so as to grip the pile K in a direction whose axis coincides with the axis of the vibration cylinder 4.

The vibration cylinder 4 is provided with an electric / hydraulic servo valve 5 for driving and controlling the vibration cylinder. Above the vibration cylinder 4, a piston displacement detector 7 for detecting a displacement amount of the piston 41 is provided.

On the other hand, a transmitter 8 for generating a drive control signal for driving and controlling the electric / hydraulic servo valve 5 is provided. The transmitter 8 has an appropriate waveform such as a rectangular wave or a sine wave as shown in FIG. Can be issued. The signal emitted from the transmitter 8 is sent to the electric / hydraulic servo valve 5 via the servo amplifier 10. Further, a feedback signal circuit 9 from the piston displacement detector 7 to the servo amplifier 10 is provided, and a servo control system for controlling the vibration cylinder 4 by an electric / hydraulic servo valve is configured.

Next, the operation of the servo control system will be described with reference to FIG. 3. In accordance with the driving signal from the transmitter 8, the spool 52 in the electric / hydraulic servo valve 5 is controlled in accordance with the polarity of the signal and the magnitude of the current. Moves, whereby the piston 41 of the vibration cylinder 4 is displaced upward or downward. (The operation of the electro-hydraulic servo valve 5 will be described later with reference to FIG. 4.) The movement direction and displacement of the piston 41 are detected by the piston displacement detector 7, and a feedback signal (voltage ) Is sent to the servo amplifier 10. In the servo amplifier 10, the signal (voltage) from the transmitter 8 and the feedback signal are compared and transmitted to the electro-hydraulic servo valve 5 in the form of an input current, and the piston 4 is moved in a direction to reduce the deviation between the two signals.
Move 1 Thus, the piston 41 of the vibration cylinder 4 can be vibrated according to the waveform of the signal of the transmitter 8. The signal to be emitted from the transmitter 8, that is, the operating conditions (frequency and amplitude) of the pile driving device can be easily set in advance simply by rotating an adjustment dial (not shown) attached to the device.

Since the reaction weight 2 is fixed to the vibration cylinder 4, the vibration of the piston 41 results in a reaction force proportional to the acceleration of the piston 41, which is fixed to the lower end of the piston 41. 6 to the pile K. The transmitted force has the same frequency as the piston 41 and is proportional to the product of the mass of the reaction weight 2 and the acceleration,
Further, the force is directed in the axial direction of the vibration cylinder 4, that is, in the axial direction of the pile K.

Referring now to FIG. 4, the structure and operation of the electric / hydraulic servo valve 5 will be described. The electric / hydraulic servo valve is roughly divided into a four-way guide valve section, a torque motor section, and a hydraulic preamplifier section. The four-way guide valve portion comprises a sleeve 51 and a spool 52 slidably engaged therein. This spool 52 has lands at the center and both ends, and has four ports, namely, a pressure oil inlet P and a tank. 2 to the return port R and to the actuator, in this case the vibrating cylinder 4
The communication and blockage between the oil passages A and B are performed. The hollow cylindrical member below the spool 51 is a filter,
Fixed orifices 60 are provided at both ends.

The torque motor section includes a permanent magnet 58, an electromagnetic coil 56, and an armature 57 of the electromagnetic coil 56.
Consists of On the other hand, the armature 57 is provided so as to be rotatable around a central axis on which the rotational force of the torsion spring 55 is applied, and a flapper 54 is provided on the opposite side with respect to the central axis.
Is fixed. A feedback spring 59 is attached to one end of the flapper 54, and a spool 5 is attached to the other end.
2 at the center position via an appropriate ball. Although the nozzle 53 of the pair at each end of the flapper 54 is opposed, communicates with both ends of each of these nozzles 53 are spool 52 (the P _1, P _2, respectively the pressure applied thereto), the pressure oil flow Part of the pressure oil flowing from the inlet P forms a flow path through the left and right fixed orifices 60. The flapper 54, the pair of nozzles 53, and the fixed orifice 60 described above form a hydraulic preamplifier.

When the input signal current to the electro-hydraulic servo valve 5 is 0, the armature 57, and thus the flapper 54, is at the center position as shown in the figure, and the back pressure of the left and right nozzles 53, ie, the pressures P ₁ and P ₂ The size is equal and the spool 5
2 is stopped at the illustrated center position. Now, a minute current (input signal) of either positive or negative polarity flows through the electromagnetic coil 56, and the magnetic field of the permanent magnet 58 changes, and the armature 57
Suppose, on the other hand, it has been displaced to the left, for example,
Flapper 54 is displaced to the right, the order nozzle back pressure P ₂ on the right side is higher than the nozzle back pressure P ₁ on the left side (P _2> P
₁ ), the spool 52 is displaced to the left. This spool 5
2 is displaced by the feedback spring 59 due to its displacement.
Pulls back the flapper 54 to the left and continues until the nozzle back pressure rebalances, at which point the spool 52 returns to that position.
Stops. The communication relationship between the four ports of the four-way guide valve at the stop position of the spool 52 is such that the pressure oil flows in the pressure oil inlet port P → A → vibration cylinder 4 → B → return port R. If the port A is communicated with the head side of the vibration cylinder 4, the piston 41 is extended by the input signal described above. When the input signal whose polarity is different from the above-mentioned case is applied, the same operation is of course performed, and the spool 52 is displaced rightward by a certain amount. In this way, electricity
In a hydraulic servo valve, the output flow rate is proportional to the input current by displacing the spool to a position proportional to the magnitude of the input signal current.

By using the electric / hydraulic servo valve 5 in this manner, a large-capacity actuator can be controlled by a minute electric signal of approximately several milliamps. In addition, the servo control system including the piston displacement detector 7, the transmitter 8, the feedback signal circuit 9, and the servo amplifier 10 can faithfully follow the magnitude of the current value of the electric signal and the positive and negative polarities. It has been confirmed that, under the cooperation of the above, it is possible to sufficiently follow the oscillating change of the input signal of several tens Hertz while keeping the reaction weight 2 near the center. Fig. 4 shows the most typical two-stage electro-hydraulic servo valve for easy understanding of the operation principle. However, if you want to control a larger capacity actuator, use the three-stage electro-hydraulic servo valve. A valve may be used. Of course, even with a three-stage electric / hydraulic servo valve, the principle of making the displacement of the spool proportional to the input current and controlling the output flow rate is the same.

When actually driving the stake K, as shown in FIG. 5, a traction force applying wire 15 fed from a winch 18 of a leader guide holding wheel 17 is wound around a guide roller 16 provided at the lower end of the leader guide 11, and It is connected to the lower part of the mounting frame 1. On the other hand, the entire apparatus including the mounting frame 1 is suspended and supported from the upper end of the leader guide 11 using the hanging rope 14, and the hanging rope 16 is allowed to freely extend in accordance with the driving of the pile K.
Therefore, the force acting on the pile K at the time of driving the pile K is not only the reaction force by the vibration cylinder 4 described above, but also the own weight of the reaction force weight 2 and the traction force applying wire 15 by the winch 18.
Is the traction provided through the As another embodiment, as shown in FIG. 7, the leader guide 11 and the traction force applying device 15 and the like are omitted, and the mounting frame 1 is simply suspended from an arm or the like of an appropriate construction machine, and the pile K is
It is good also as a structure which can be piled out only by the reaction force of the reaction force weight 2 by the vibration of.

On the other hand, when pulling out the pile K from the soil, FIG.
As shown in (1), after the traction force applying wire 15 extending from the winch 18 is wrapped around the guide roller 19 located at the upper end of the leader guide 11, the wire 15 is connected to the upper part of the mounting frame 1, actually to the suspension plate 12. Then, unlike at the time of driving, the pile K is pulled out by applying the traction force of the winch 18 and the reaction force of the vibration cylinder 4 upward. The dead weight of the reaction weight 2 is of course applied downward in the opposite direction. In addition,
A fluid pressure cylinder fixed to the leader guide may be provided as a traction force applying device, and the mounting frame 1 may be directly connected to this rod to apply traction force from this.

[0018]

As described above, the present invention utilizes the reaction force generated by the vibration cylinder that is servo-controlled,
Further, in some embodiments, the pile is driven by using a relatively large traction force which is accurately applied in the axial direction of the pile by the traction force imparting device, and therefore, (1) the pile can be efficiently driven or pulled out. (2) Since the vibration cylinder is driven by an electric / hydraulic servo valve operated by an electric signal, the frequency and amplitude can be easily adjusted just by turning the dial. (3) The vibration transmitted to the pile is high frequency vibration. The damping is so rapid that it can avoid damaging adjacent areas. (4) By setting the amplitude to zero when starting and stopping the pile driver, it is possible to eliminate the impact on the base machine. ) The force input by the winch of the leader guide holding vehicle and the exciting force by the vibrating cylinder are applied independently to the pile, so that a large synergistic effect can be obtained.
(6) Since it is used in conjunction with the leader guide holding vehicle, it is easy to move and can efficiently cope with many pile driving in different places. (7) Since it is a pile driving machine with a complete hitting method, concrete Without the hassle of injecting milk,
It has many excellent effects, such as easy disposal of discharged soil.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing one embodiment of the present invention.

FIG. 2 is a side sectional view of the embodiment as viewed from a direction orthogonal to the direction in which FIG. 1 is viewed.

FIG. 3 is a side sectional view showing a servo control system for controlling a vibration cylinder.

FIG. 4 is a side sectional view showing a typical example of an electric / hydraulic servo valve.

FIG. 5 is a side view showing an actual pile driving operation state of the device of the present invention.

FIG. 6 is a side view showing a state in which a pile is pulled out by the device of the present invention.

FIG. 7 is a side view showing an actual pile driving operation state by another embodiment device of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 mounting frame 2 reaction weight 3 cushion rubber 4 vibration cylinder 5 electric / hydraulic servo valve 6 chuck means 7 piston displacement detector 8 transmitter 9 feedback signal circuit 10 servo amplifier 11 leader guide 15 traction wire 16 guide roller 17 leader guide Holding wheel 18 Winch 19 Guide roller

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Kiyozo Kumai 3-6-4 Akabaneishi, Kita-ku, Tokyo (56) References JP-A-3-279514 (JP, A) JP-A-59-145828 (JP, A) JP-A-61-72121 (JP, A) JP-B-47-48723 (JP, B1) (58) Fields investigated (Int. Cl. ⁷ , DB name) E02D 7/18

Claims (3)

(57) [Claims] 1. A mounting frame (1) suspended from an appropriate support such as an arm of a construction machine, and a vibration cylinder (4) supported on the mounting frame (1) via a cushion rubber (3). And a reaction force weight (2) provided on the upper side of the vibration cylinder (4) in the axial direction, and a pile (K) provided on the opposite side to the reaction force weight (2) with respect to the axial direction and to be driven. Chuck means (6) for gripping so as to coincide with the axis of the vibration cylinder (4), an electro-hydraulic servo valve (5) for driving and controlling the vibration cylinder (4), and an electro-hydraulic servo valve ( 5) a servo control system (7, 8,...) For controlling the vibration cylinder (4).
9, 10). 2. A mounting frame (1) slidably provided along a leader guide (11) fixedly held in an upright state, and supported by said mounting frame (1) via a cushion rubber (3). A vibrating cylinder (4), and a reaction weight (2) provided above the vibrating cylinder (4) in the axial direction.
A chuck means (6) provided on the opposite side to the reaction weight (2) with respect to the axial direction, for gripping a pile (K) to be driven so that its axis coincides with the axis of the vibration cylinder (4). An electric / hydraulic servo valve (5) for driving and controlling the vibration cylinder (4); and a servo control system (7, 8, 9, 9) for controlling the vibration cylinder (4) by the electric / hydraulic servo valve (5). 10). 3. A mounting frame (1) slidably provided along a leader guide (11) fixedly held in an upright state, and a mounting frame (1) provided on the mounting frame (1). A tractive force imparting device (15, 16, 17, 18, 18, 1) for applying tractive force in both upward and downward directions along
9), a vibration cylinder (4) supported by the mounting frame (1) via a cushioning rubber (3), and a reaction weight (2) provided on an upper side of the vibration cylinder (4) in the axial direction. Chuck means (6) provided on the opposite side of the reaction weight (2) with respect to the axial direction, for gripping a pile (K) to be driven so that its axis coincides with the axis of the vibration cylinder (4); An electric / hydraulic servo valve (5) for driving and controlling the vibration cylinder (4); and a servo control system (7, 8, 9, 10) for controlling the vibration cylinder (4) by the electric / hydraulic servo valve (5). ).