JPS6351208B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a mortar injection type pile driving method in which a hole is excavated in the ground with an earth auger, mortar is injected into the hole, and a pile is driven, and a pile driving method for carrying out this method. Regarding equipment.

In general, this type of pile driving method, as shown in Fig. 1, involves a pile driver body 1, a leader 3 erected on the front bracket of the pile driver and supported by a backstay 2, and a vertical movement along the leader 3. an earth auger 4, an auger screw 5 drivingly connected to the earth auger, a wire rope 6 for suspending the earth auger,
A piling device is used, which includes a winch drum 7 for hoisting and lowering the wire rope 6, a mortar plant 8, and a hose 11 for supplying mortar from the mortar plant 8 to the inside of the hollow shaft of the auger screw 5. Implemented.

Then, as shown in FIG. 2A, a hole 101 is excavated in the ground 100 by the auger screw 5. During excavation of the hole 101, the wire rope 6 is lowered by the winch drum 7 shown in FIG. 1, the earth auger 4 is lowered, and the auger screw 5 is rotationally driven by the earth auger 4.

After drilling the hole 101, the earth auger 4 is gradually pulled up, and mortar is supplied from the mortar plant 8 to the inside of the hollow shaft of the auger screw 5 through the hose 11 shown in FIG. As shown in Figures B and C, the mortar 102 is injected from the tip 5' of the auger 5, and the mortar 102 is poured into the pile 102 while pulling up the earth auger 4 as described above.
is poured.

During pile driving as described above, if the lifting speed of the earth auger 4, that is, the winding up of the winch drum 7, is too fast relative to the mortar flow rate, the auger screw 5
Negative pressure develops at the tip 5', causing problems such as the tip 5' being damaged, the excavation wall collapsing due to the negative pressure, mud being mixed into the mortar, and the pile strength decreasing. .

Conventionally, the output of the engine is transmitted through a transmission member such as a gear or a chain, and a clutch to a wire rope winch drum for suspending the earth auger, and the winch drum is rotationally driven. Some winch drums maintain a constant hoisting speed by controlling the rotational speed or by sliding the clutch.

On the other hand, a type of engine rotates a hydraulic pump, supplies liquid to a hydraulic motor via the hydraulic pump and a control valve, rotates the hydraulic motor, and rotationally drives a winch drum connected to the hydraulic motor. In pile driving machines, the number of revolutions of the engine is controlled to change the flow rate of liquid supplied from the hydraulic pump to the hydraulic motor, and the control valve is operated by a lever to control the flow rate of liquid supplied to the hydraulic motor. There is one in which the winding speed of the winch drum is adjusted according to the amount of injection.

However, with the former, the engine speed fluctuates depending on the load, heat is generated by sliding the clutch, the temperature of the friction surface rises, and the transmission force of the clutch fluctuates, so the winch drum is not suitable for the amount of mortar injected. In order to obtain a winding speed of
The disadvantage is that the operator must frequently operate the levers.

The latter also has the disadvantage that the operator must repeatedly operate the lever in order to adjust the engine speed or the flow rate of the liquid supplied to the hydraulic motor in order to obtain the winch drum hoisting speed commensurate with the amount of mortar injected. be.

An object of the present invention is to provide a mortar inflow type pile driving system that eliminates the drawbacks of the prior art and can appropriately and automatically control the lifting speed of the earth auger in accordance with the mortar flow rate supplied from the mortar plant to the earth auger. The object of the present invention is to provide a pile driving device that can reliably implement the method.

The mortar injection type pile driving method of the present invention detects the mortar flow rate fed into the earth auger excavated into the ground, calculates the lifting speed of the earth auger from the detected value, and uses the calculated value as the Based on this, the flow rate of liquid supplied to a hydraulic motor that rotationally drives a winch drum of a wire rope for suspending an earth auger is controlled.

Furthermore, the mortar injection type piling device of the present invention has a variable displacement hydraulic pump connected to a hydraulic motor that rotationally drives a winch drum for lifting and lowering an earth auger, and a variable displacement section of the variable displacement hydraulic pump. is connected to a control fluid pressure pump, a controller is provided in a passage connecting the variable capacity section and the control fluid pressure pump, a mortar flow rate detector is attached to a mortar plant that supplies mortar to the earth auger, and a mortar flow rate detector is installed in a mortar plant that supplies mortar to the earth auger. A computing device located between the flow rate detector and the controller that takes in the detected value from the mortar flow rate detector, computes the lifting speed of the earth auger corresponding to the mortar flow rate, and inserts a signal corresponding to the computed value into the controller. The present invention is characterized in that the liquid discharge amount of the variable displacement hydraulic pump is controlled by a controller in accordance with the calculated lifting speed of the earth auger when the earth auger is pulled up.

Hereinafter, details of the present invention will be explained with reference to the drawings.

FIG. 3 shows an embodiment of a pile driving device that implements the mortar injection type pile driving method of the present invention. A winch drum 7 that winds up and lowers a wire rope for hanging an earth auger is driven by a hydraulic motor 12. A counterbalance valve 13, a switching valve 14 for controlling the hydraulic motor, and a variable displacement hydraulic pump 17 are connected in series to the hydraulic motor 12.

The switching valve 14 for controlling the hydraulic motor is a 4-port, 3-position switching type, and has first and second operation parts 1.
A hydraulic switching type is used in which 5 and 16 are operated by hydraulic pressure.

The variable displacement hydraulic pump 17 is attached with a cylinder 18 which is a variable displacement section. The variable displacement hydraulic pump 17 is configured to discharge the lowest flow rate of liquid when the pressure inside the cylinder 18 is zero.

A relief valve 1 is provided in the passage connecting the switching valve 14 for controlling the hydraulic motor and the variable displacement hydraulic pump 17.
9 is provided.

The first and second operation parts 15 and 16 of the switching valve 14 for controlling the hydraulic motor are provided with first and second passages 2.
A control valve 22 is connected to the control valve 22 through a passage 26, and a control hydraulic pump 2 is connected to the control valve 22 through a passage 26.
7 is connected. Said first and second passages 2
A check valve 28 is provided between 0 and 21.

The control valve 22 has an operating lever 23 and first and second control valves 24 and 25, and is discharged from the control hydraulic pump 27 by operating the operating lever 23 in the direction of arrow a. By flowing the liquid from the first control valve 24 to the first passage 20 to the first operating portion 15 of the switching valve 14, switching the switching valve 14 to the A position, and operating the operating lever 23 in the direction of arrow b. The liquid discharged from the control hydraulic pump 27 is caused to flow through the second control valve 25 → second passage 21 → the second operating portion 16 of the switching valve 14, the switching valve 14 is switched to the C position, and the operating lever is 23 is set to the neutral position, the switching valve 14 can be switched to the neutral position (B).

A switching valve for controlling the variable displacement hydraulic pump is provided between the check valve 28 provided between the first and second passages 20 and 21 and the cylinder 18 of the variable displacement hydraulic pump 17 via passages 29 and 31. 30 are provided. Further, this switching valve 30 is connected to the control hydraulic pump 27 through a passage 32.

A servo valve 35 serving as a controller is provided in the passage 32 connecting the control hydraulic pump 27 and the switching valve 30 for controlling the variable displacement hydraulic pump, and a relief for preventing a control liquid pressure rise is provided on the upstream side of the servo valve 35. A valve 36 is provided.

As the switching valve 30 for controlling the variable displacement hydraulic pump, a 3-port, 2-position switching type solenoid valve is used. This switching valve 30 is connected to an electric circuit having a battery 33 and a switch 34, and when the switch 34 is closed, it is switched from the A position to the B position.
The liquid discharged from the passage 32→servo valve 35→
Insert into the cylinder 18 of the variable displacement hydraulic pump 17 through the B-C port of the switching valve 30 → the passage 31,
When the switch 34 is opened, the switch 34 is switched from the B position to the A position, and the liquid discharged from the control hydraulic pump 27 is transferred to the hydraulic motor control switching valve 1.
A check valve 28 provided between the first and second passages 20 and 21 facing the pump 4→passage 29→AC port of the switching valve 30→can be inserted into the cylinder 18 of the variable displacement hydraulic pump 17 through the passage 31. As such, it is connected to related members.

On the other hand, a mortar plant 8 that supplies mortar to the inside of the earth auger includes a mortar tank 9 and a mortar pump 10, and a hose 11 is connected between the mortar pump 10 and the earth auger 4 shown in FIG.
The mortar discharged from the mortar pump 10 can be pumped into the earth auger 4 through the hose 11.

In the middle of the mortar supply hose 11,
A mortar flow rate detector 37 is provided, a converter 38 is connected to the mortar flow rate detector 37 for converting the detected value into an analog quantity of electricity, etc., and a computing unit 39 is connected to the converter 38. .

The computing unit 39 takes in the signal output from the converter 38, computes the lifting speed of the earth auger 4 corresponding to the flow rate of the mortar, and transmits the computed value to the servo, which is the controller of the variable displacement hydraulic pump 17. It is configured to be inserted into the valve 35.

Next, an embodiment of the mortar injection type pile driving method of the present invention will be described along with the operation of the pile driving apparatus of the above embodiment.

When drilling a hole, the switching valve 30 for controlling the variable displacement hydraulic pump is switched to the A position, and then the control valve 2 is switched to the A position.
When the second operating lever 23 is repeatedly operated in the direction of opening the first control valve 24 or the second control valve 25 of the control valve 22, the liquid discharged from the control hydraulic pump 27 is First control valve 24 → first passage 20 → hydraulic pressure First operating part 15 of switching valve 14 for motor control, or second control valve 25 of control valve 22 → second passage 21 → hydraulic pressure Flows to the second operation part 16 of the switching valve 14 for motor control,
The switching valve 14 is switched to position A or C,
The direction of the liquid supplied from the variable displacement hydraulic pump 17 to the hydraulic motor 12 through the switching valve 14 and the counterbalance valve 13 is changed, and the winch drum 7
is driven to rotate in the forward or reverse direction, the wire rope 6 for hanging the earth auger shown in FIG. 1 is wound up or lowered, the earth auger 4 is repeatedly raised and lowered,
A hole 101 is dug.

Also, when digging a hole, the first valve 24→first passage 20→corresponding to the operating stroke of the operating lever 23
First operation part 1 of switching valve 14 for hydraulic motor control
5, or second relief valve 25 → second passage 2
1 → Second operation part 1 of the switching valve for hydraulic motor control
At the same time as the liquid flow rate supplied to 6 is controlled,
Check valve 28 provided between the first and second passages 20 and 21 → passage 29 → A-C port of switching valve 30 for controlling variable displacement hydraulic pump → passage 31 →
The flow rate of liquid supplied to the cylinder 18 of the variable displacement hydraulic pump 17 is also controlled, thereby controlling the discharge amount of the variable displacement hydraulic pump 17, and the hydraulic motor 1
2 is controlled, the rotational speed of the hydraulic motor 12 and the winch drum 7, and the hoisting and hoisting speeds of the wire rope 6 for suspending the earth auger are controlled. The raising and lowering speed of the earth auger 4 can be controlled to an optimum speed by lever operation in accordance with the operation stroke.

During the aforementioned drilling, the mortar plant 8 and the members attached to the passage 32 connecting the control hydraulic pump 27 and the variable displacement hydraulic pump control switching valve 30 are at rest.

After drilling a hole, when injecting mortar into the hole 101, close the switch 34, change the changeover valve 30 for controlling the variable displacement hydraulic pump to the ``ro'' position as shown in Figure 3, and switch the hydraulic motor 12 to the ground auger. After switching the switching valve 14 for controlling the hydraulic motor so that it can be rotated in the lifting direction of the mortar plant 8, the mortar pump 10 of the mortar plant 8 is started.

As a result, mortar is supplied to the inside of the earth auger 4 shown in FIG. 1 through the mortar pump 10 and the hose 11.

During this time, the mortar flow rate discharged from the mortar pump 10 is detected by the mortar flow rate detector 37, and the detected value is inserted into the converter 38, where it is converted into an analog quantity, etc., and the signal is sent to the computer. 39 is inserted. The calculating unit 39 calculates the lifting speed of the earth auger 4 from the detected value of the mortar flow rate, and a signal corresponding to the calculated value is inserted from the calculating unit 39 to the servo valve 35, and the servo valve 35 controls the hydraulic pump for control. 27 to aisle 3
2 through a switching valve 3 for controlling a variable displacement hydraulic pump.
The liquid flow rate towards zero is controlled.

Therefore, the flow rate of liquid corresponding to the lifting speed of the earth auger 4 calculated by the calculator 39 flows through the switching valve 30 for controlling the variable displacement hydraulic pump.
The liquid is transferred from the B-C port of the switching valve 30 to the passage 3.
1 through cylinder 1 of variable displacement hydraulic pump 17
8, the discharge amount of the variable displacement hydraulic pump 17 is controlled in accordance with the calculated lifting speed of the earth auger 4, and the liquid is supplied to the switching valve 14 for hydraulic motor control and the counterbalance valve. 13
The hydraulic motor 12 and the winch drum 7 are driven to rotate at a rotational speed corresponding to the calculated lifting speed of the earth auger 4, and the wire rope 6 shown in FIG. The earth auger 4 is pulled up at the calculated lifting speed.

During this time, mortar is continuously fed into the earth auger 4 from the mortar plant 8, and the mortar 102 is injected into the hole 101 from the tip 5' of the auger screw 5, as shown in FIG. 2B. Piles 103 are driven as shown in FIG. 2C.

In addition, in the present invention, the switching valve 1 for hydraulic motor control is
4 and the control medium of the switching valve 30 for controlling the variable displacement hydraulic pump is not limited to the above-mentioned hydraulic pressure, but general hydraulic pressure can be used.

According to the construction method of the present invention described above, the flow rate of mortar fed into the inside of the earth auger is detected, the lifting speed of the earth auger is calculated from the detected value, and the wire for hanging the earth auger is connected based on the calculated value. Since the flow rate of liquid supplied to the hydraulic motor that rotates the rope winch drum is controlled, the lifting speed of the earth auger can be automatically controlled to the optimum speed when injecting mortar into the hole. This has the effect of eliminating all inconveniences caused by poor pulling speed.

Further, according to the device of the present invention, there is provided a variable displacement hydraulic pump that supplies liquid to a liquid motor that rotationally drives a winch drum for lifting and lowering an earth auger, a variable displacement section of the variable displacement hydraulic pump, and a control fluid. A controller installed between the pressure pumps, a mortar flow rate detector attached to the mortar plant,
The construction method of the present invention can be reliably carried out by working in conjunction with a calculator that calculates the lifting speed of the earth auger corresponding to the mortar flow rate from this detected value and inserts a signal corresponding to the calculated value into the controller. It has a soothing effect.

[Brief explanation of drawings]

Figure 1 is a schematic explanatory diagram of the pile driving equipment used in the mortar injection pile driving method, and Figures 2 A, B, and C show the process of drilling a hole for mortar injection, injecting mortar, and driving the pile. 3 are system diagrams showing an example of a pile driving device for carrying out the construction method of the present invention. 4...Earth auger, 5...Earth auger screw, 6...Wire rope for hanging the earth auger, 7...Winch drum for hoisting and lowering the same wire rope, 8...Mortar plant, 10... ... Mortar pump, 11 ... Hose for supplying mortar, 12 ... Hydraulic motor that rotationally drives the winch drum for hoisting and lowering the wire rope for hanging the earth auger, 14 ...
A switching valve for hydraulic motor control, 17...variable displacement hydraulic pump, 18...a cylinder which is a variable capacity part,
22...control valve, 23...operation lever, 27...
A control hydraulic pump, which is a control hydraulic pump, 2
8...A check valve provided between the first and second passages connecting the control valve and the switching valve for controlling the hydraulic motor;
30...Switching valve for variable displacement hydraulic pump control, 3
2... Passage connecting the control hydraulic pump and the switching valve for controlling the variable displacement hydraulic pump, 35... Servo valve as a controller for the variable displacement hydraulic pump, 37... Mortar flow rate detector, 38... ...converter, 39...computer, 100...ground, 101...hole drilled in the ground, 102...mortar, 103...pile.

Claims (1)

[Scope of Claims] 1. A construction method in which a hole is excavated in the ground with an earth auger, and after the excavation, mortar is injected into the hole from the tip of the earth auger through the inside of the earth auger while pulling it up, and a pile is driven, The flow rate of mortar fed into the earth auger is detected, the lifting speed of the earth auger is calculated from the detected value, and a winch drum of a wire rope for suspending the earth auger is rotated based on the calculated value. A mortar injection pile driving method characterized by controlling the flow rate of liquid supplied to a driving hydraulic motor. 2. A device that excavates a hole in the ground with an earth auger, and after the excavation, injects mortar into the hole from the tip of the earth auger while pulling up the earth auger, and drives a pile. A variable displacement hydraulic pump is connected to the hydraulic motor that rotates the drum, and
A mortar plant in which a variable capacity part of the variable capacity hydraulic pump is connected to a control fluid pressure pump, a controller is provided in a passage connecting the variable capacity part and the control fluid pressure pump, and mortar is supplied to an earth auger. installs a mortar flow rate detector, takes in the detected value from the mortar flow rate detector between the mortar flow rate detector and the controller, calculates the lifting speed of the earth auger corresponding to the mortar flow rate, and responds to the calculated value. A calculator is provided for inserting a signal into the controller, and the liquid discharge amount of the variable displacement hydraulic pump is controlled by the controller in response to the calculated lifting speed of the earth auger when the earth auger is pulled up. A mortar injection type pile driving device characterized by: