JPS5998928A - Controller for frequency generated in high-frequency vibro-pile driver - Google Patents

Abstract

PURPOSE:To regulate the resonance frequency of a pile by a method in which a load detector is provided to a connector to be connected to the basal end of the pile, and detected load is put in a controller capable of optionally setting frequencies to set up a frequency at which the switching speed of a switch valve is increased to a maximum. CONSTITUTION:Oil chambers 5 and 6 facing each other of a double-acting cylinder 1 reciprocally moved by high frequency by means of oil pressure are alternately connected to a high-pressure oil path and a discharge oil path by a switch valve 2, an inertial mass is set on the cylinder 3 side or the piston 4 side of the cylinder 1, and load of a pile driver is detected by a sensor 20. A controller 12 to control the switching frequency of the switch valve 2 is also provided, and the switching frequency of the valve 2 is increased or reduced within a small range periodically by the controller 20. During the period, set switching frequency is reset in such a way that the detected load of the sensor 20 becomes maximum.

Description

[Detailed description of the invention] A double-acting piston-cylinder unit that reciprocates at high frequency using hydraulic pressure is connected alternately to a high-pressure oil path and a discharge oil path through two opposing oil chamber full-switch valves. By doing so, the piston-cylinder unit is configured to vibrate at a high frequency, and an inertial mass as a vibration reaction force is provided on one of the piston side or the cylinder side of the piston-cylinder unit, and a pile base is provided on the other side. A high-frequency vibrating pile driver equipped with a connector that connects the ends can easily adjust the total number of vibrations generated by simply changing the switching speed of the switching valve, so it is easy to Adjust the base end of the pile by the number of resonant pieces in the longitudinal direction of the pile.1. B. It enables what is called a resonant pile driving operation in which the pile is driven into the ground by causing resonant vibrations. And resonant piling operations achieve highly efficient piling operations. However, it is extremely difficult to accurately match the frequency generated by a high-frequency vibrating pile driver to the number of resonant pieces of a pile. The vibration frequency of the high-frequency vibrating pile driver was adjusted to maximize the penetration speed. However, such intuitive adjustment of the generated vibration frequency requires a great deal of effort on the part of the operator.

In view of the current situation on 1 tatami mats, the present invention provides a control device for the frequency of vibration generated by a high-frequency vibrating pile driver, which can automatically adjust the frequency generated by the high-frequency vibrating pile driver to the number of resonant pieces of the pile. This is what we are trying to provide.

The present invention provides that when a pile causes a vibration force applied by a high-frequency vibrating pile driver attached to its base end, the mechanical impedance of the pile becomes maximum, and in response to this, a high-frequency vibrating pile This focuses on the fact that the load on the hitting machine is maximum.

The aim is to make full use of this phenomenon to automatically control the frequency of vibration generated by a high-frequency m-dynamic pile driver. Namely.

The two opposing oil chambers of a double-acting piston-cylinder unit that reciprocates at high frequency using hydraulic pressure are alternately connected to a high-pressure oil path and a discharge oil path using a switching valve. The piston-cylinder unit is configured to be vibrated and driven by high frequency waves, and the inertial mass as a vibration reaction force is all disposed on one of the piston side or the cylinder side of the piston-cylinder unit, and the other side is equipped with a connecting device for connecting the base end of the pile. A high-frequency vibrating pile driver applies vibration force to the base of the pile.

The control means controls the switching frequency of the terrain switching valve by causing resonance vibration in the longitudinal direction of the pile, and the control means controls the switching frequency of the switching valve at a set switching frequency, and periodically controls the switching frequency of the switching valve. The switching frequency of the switching valve 12 fluctuates in a minute range, and the set switching frequency is reset to the switching speed of the switching valve at which the load detected by the detection means is maximum during this fluctuation. This invention relates to a control device for the frequency of vibration generated by a high-frequency vibrating pile driver.

Embodiments of the present invention will be described in detail below based on the drawings.

In the figure, A is a high-frequency vibrating pile driver, and B is a pile driven into the ground by the high-frequency vibrating pile driver A with full vibration force applied to its base end. The high-frequency vibration pile driver A is comprised of a moving piston-cylinder unit 1, which will be described later, and a switching valve 2 that controls the supply and discharge of hydraulic oil to the piston-cylinder unit 1. The double-acting piston-cylinder unit 1 includes a cylinder 3 and two oil chambers 5 that are slidably inserted into the cylinder 3 and face each other inside the cylinder 3.
．． It consists of 4 pistons divided into 6 sections. The piston 4 of the piston-cylinder unit 1 has a piston rod 8 extending out of the cylinder 3 through an oil chamber 5 and an end wall 7 of the cylinder 3 .

The oil 6 and the end wall 9 of the cylinder 3 completely penetrate through the cylinder 3.
It has an outwardly extending ratio piston rod 10, and is provided with a connecting tool 11 for fully connecting the base end of the pile B to the outer end of the piston rod 8 of the piston 4. The cylinder 3 has a large inertial mass so that it acts as a vibration reaction force. In the embodiment, the pile connector 11 is attached to the piston 4 side, and the inertia t as a vibration reaction force is attached to the cylinder 3 side, but in other embodiments.

The entire inertial mass as a vibration reaction force may be attached to the piston 4 side, and the connecting tool 11' of the pile B may be attached to the sill 3 side. The oil chambers 5 and 6 of the piston-cylinder unit 1 are alternately connected to a high-pressure oil passage 13 and a discharge oil passage 14 via switching valves 2. The switching frequency of this switching valve 2 is controlled by a control means 12. The control means 12 includes the switching valve 2'@: a switching valve private drive device 18 consisting of a hydraulic motor 15 that rotationally drives the switching valve 2' and a flow rate control 9'P17 interposed in the hydraulic circuit 1!316 of the hydraulic motor 15.
．． and a control signal generating device 19 for fully controlling the flow rate passing through the flow rate control valve 17 of the switching valve moving device 18. The flow rate control valve 17 of the switching valve moving device 1B is provided on the discharge side of the hydraulic motor 15, and is controlled by an electric signal. The high-frequency vibration pile driver A supplies high-pressure oil to the high-pressure oil passage 13 and drives the hydraulic motor 1.
By operating the p-switching valve 2 in the piston-cylinder unit 5, the two oil chambers 5 and 6 of the piston-cylinder unit are alternately connected to the high-pressure oil passage 13 and the discharge oil passage 14, and the piston 4 and cylinder W are vibrated relative to each other. It is something that is driven. The vibration force generated by the high-frequency vibration pile driver A is transmitted to the base end of the pile B through the connection All' (r. The frequency transmitted to the base end of the pile B is the resonance of the pile B!i!II When the number matches, the pile B causes resonance vibration.

Generally, the number of resonant pieces of the pile B is expressed as C/4L, where the length of the pile B is multiplied by the speed of the sound wave that propagates throughout the resistance B, 2c. Pile B is C! When resonant vibration is caused at a frequency of /4L, the displacement of the appeal part with the base end of the pile B as a reference becomes as shown in FIG. (In Figure 1, the horizontal axis shows the displacement number for convenience.) When pile B causes resonance vibration in this way, a large vibration amplitude is generated at the tip of pile B, which makes it possible to drive extremely efficiently. k can be achieved. 20 is.

mel transmitted from high frequency vibration pile driver A to the base of pile B
t-, a vibration force transmission path from the piston 4 of the piston-cylinder unit 1 to the coupling 11, that is, a load detection means attached to the piston rod 8, and the load detection means 20 detects the strain of the piston rod 8. Contains a strain gauge that converts the signal into an electrical signal. The output signal of the load inspection means 20 is a half cycle in which the vibration force generated by the high frequency vibrating pile driver A pushes down the pile B base, and a half cycle of the pile B base?
During the variation of the load in the upward half-cycle, it is processed into a corresponding signal and transmitted to the control signal generator 19 in the control means 12. In the control signal generator 19,
A set frequency reset section 21 that generates all set frequency signals.
Set frequency switch 4') A fluctuation signal generator that is interposed in the signal transmission path for transmitting the set frequency signal generated by the setting section 21 to the flow rate control valve 17) and causes the set frequency signal to periodically vary within a minute range. The set frequency reset section 21
A signal corresponding to the load fluctuation detected by the load detection means 20 is inputted to the flow rate 1t! which is applied to the flow rate control valve 17 via the fluctuation signal generator 22'e. A control signal for the control valve 17 is input. The control signal generator 19 functions like a first-order signal generator. First, when an initial value is set in the initial value setting section 23 (which can be set arbitrarily by the operator), this is input to the set frequency reset section 21. The set frequency reset unit 21 transmits a signal corresponding to the input initial value signal to the flow rate control valve 17 via the fluctuation signal generator 22 as a set frequency signal. The flow rate control valve 17 controls the entire flow rate of the high-frequency vibrating pile driver A so that the pile driver A vibrates at a frequency corresponding to this set frequency signal. Flow rate control;ll'
Since the set frequency signal given to f'17 periodically fluctuates in a minute range by the fluctuation signal generator 22, the vibration frequency of high frequency vibration pile driving ff1A periodically changes to the set frequency? It fluctuates in a range of a dozen hertz around the center. The set frequency reset unit 21 includes the fluctuation signal generator 22 as described above.
The set frequency signal (
This signal is input to the high-frequency vibrating pile driver A (which is a signal responsive to the vibration frequency D), and is also input to the load detection means 20.
Corresponding signals are input during the load fluctuation detected in 2, and using these signals 2, the set frequency reset section 21 resets to the set frequency signal as follows. That is, while the fluctuation signal generator 22 increases or decreases the set frequency signal 1- corresponding to the initial value signal of the initial value setting unit 23 in a minute range (the high-frequency vibrating pile driver A Changes in the load during one cycle of vibration detected by the load detection means 20 (while the frequency is fluctuating in the range of several hertz)
Monitor all 6 widths and see what happens when the load fluctuation range is maximum! The signal value given to the control valve 17 (this signal value line is transmitted from the high-frequency vibration pile driver A to the pile B within the range in which the frequency of the high-frequency vibration pile driver mA fluctuates at the initial setting frequency signal of 10-odd Hertz) The first set frequency signal is reset to a value corresponding to the vibration frequency of the high-frequency vibrating pile driver A that is maximum during load fluctuation during one vibration cycle. and 1
In the next step, the reset setting frequency signal is input to the flow rate control valve 17 via the fluctuation signal generator 22. The control signal generator 19 functions as described above. B automatically brings the set frequency signal closer to the frequency at which resonance vibration occurs.

Other examples of the load detection means 20 of the high frequency vibration pile driver A include the following.

One of them is to install a pressure sensor (not shown) in at least one of the two oil chambers 5 and 6 of the piston-cylinder unit 1 of the high-frequency vibration pile driver A to detect the pressure inside the oil 5 and 6. According to the present invention, the operator sets the approximate vibration mD number in the initial value setting section 23 when driving a pile. , the frequency of high frequency vibration frequency?
Because it can automatically control the number of resonant pieces of the pile,
It can be used to achieve extremely efficient pile driving work.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of a control device for the generated vibration frequency of a high-frequency vibrating pile driver according to the present invention. A; High frequency vibration pile driver B; Pile 1; Piston-cylinder unit 2S switching valve 3; Cylinder 4N Piston 5; 6; Oil chamber 11; Connector 12; Control means 13; High EE oil path 14 Discharge pipe 20; Load detection means 1 岨 0 1, Indication of the incident 1982 Patent Application No. 207970 2, Name of the invention Control device for the frequency generated by a high-frequency vibration pile driver 3, Person making the correction 5, Amendment Date of order: Showa year, month, day (shipped on Showa year, month, day) 6. Column 7, “Detailed description of the invention% 7)” of the specification to be amended, Contents of the amendment (1) Specification 1, page 12, line 6 Insert the next sentence next to 0 ``In addition, the high-frequency vibration pile driving mA is only held by a leader (not shown) that slidably guides the cylinder 3 in the driving direction of the pile B. Pile driver A and the dead weight of pile B may be placed on the tip of pile B to drive pile B into it, or alternatively, high-frequency vibration pile driver A may be suspended by a crane, etc., and the crane, etc., may be lowered. It is also possible to drive the pile Bi without limiting the speed.When driving the pile B in the former manner, a driving speed detector is provided to detect the driving speed of the pile B, and this driving speed If the pile driving speed detected by the detector is less than a predetermined speed, the amount of oil supplied to the high pressure oil passage 13 is increased to increase the amplitude of high frequency vibration pile driving @A, and the predetermined speed is increased. In the above case, the high pressure oil line 13
In order to obtain an appropriate pile driving speed, reduce the amount of oil supplied to the pile driver A and reduce the vibration amplitude of the high frequency vibration pile driver A. Able to carry out reasonable pile driving work. in this case,
The amount of oil supplied to the high-pressure oil passage 13 can be increased or decreased by controlling the rotational speed of a power source such as an engine that drives a pump (not shown) that supplies pressure oil to the high-pressure oil passage 13. ”

Claims (1)

[Claims] (1) Two opposing oil riches of 5.6 V of a double-acting piston-cylinder unit 1 that is reciprocated by hydraulic pressure and high frequency.
f', high pressure oil FM513 and discharge oil path 1 by switching valve
By alternately connecting to 4, the piston-cylinder unit) lt- is configured to be vibrated at high frequency, and IrIJ
A high-frequency vibrating pile driver in which an inertial mass as a vibration reaction force is disposed on one of the piston 4 side and the μ cylinder a side of the piston-cylinder unit 1, and a connector 11 for connecting the base end of the pile B to the other side. Vibration generated by a high-frequency vibrating pile driver in the pile driving row where machine A applies vibration force to the base end of pile B, causing resonant vibration in the longitudinal direction of pile B and driving the pile into the ground. The control device is a number control device consisting of means 20 for inspecting the load acting on the high-frequency vibrating pile driver A, and a control means 12 for controlling the switching frequency of the switching valve, and the control means 12
teeth. Said switching valve at the set switching frequency! =i'i Switching control is performed, and the switching frequency of the switching valve is periodically increased or decreased within a minute range, and the switching speed of the switching valve is the maximum during load fluctuation detected by the detection means 20 during this fluctuation. A control device for a generated vibration frequency of a high-frequency vibrating pile driver, characterized in that the control device is configured to reset the setting switching frequency. (2) The means for detecting the load acting on the high-frequency vibration generator A is a transmission force detector installed in the vibration force transmission path from the piston 4@ or cylinder 3 side of the piston-cylinder unit 1 to the connector 11. A control device for the frequency of vibration generated in a high-frequency vibrating pile driver according to claim 1, characterized in that the device comprises: (8) The means for detecting the load acting on the high-frequency vibration pile driver A is constituted by a pressure detector that detects the output of at least one of the two oil chambers 5 and 6 of the piston-cylinder unit 1. 7. A control device for the frequency of vibration generated in a high-frequency vibrating pile driver according to claim 1.