JPH0137526B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method and apparatus for drilling an expanded hole when constructing an expanded bottom pile using the earth drilling method.

(Background technology) When constructing an expanded bottom pile using the earth drill method, excavated earth and sand from the expanded bottom section are taken into a bucket with a cylindrical case located in the center of the hole and pulled up to the ground. After discharging the excavated earth and sand, the bucket is lowered into the excavation hole again and the expanded bottom portion is excavated.
Repeat this process several times to complete the excavation of the expanded bottom part. At this time, there was a problem that if the depth in the repeated excavation differed from the depth in the initial excavation process, the correct shape of the bottom expansion pile could not be obtained. Further, if the excavation of the expanded bottom part is performed in a vertical direction, there is a problem that the correct shape of the expanded bottom pile cannot be obtained, as described above. In addition, if you start excavating the expanded part at a shallow depth instead of the depth that was excavated last time, the bottom of the bucket will not touch the bottom of the expanded hole, making the bucket unstable and causing severe vibration during excavation. However, since it is not possible to determine on the ground whether the pile is swaying because it has not landed on the bottom of the borehole, it is not possible to determine this from an operational point of view. Because of the problem of not being able to obtain the desired shape, the reliability of the piles was severely lacking.

(Objective of the present invention) An object of the present invention is to improve the problems of the prior art as described above and to provide an excavation method and apparatus for obtaining the correct shape of a bottom-expanded pile in the earth drilling method.

(Structure of the present invention) The excavation method in the earth drilling method according to the present invention will be explained with reference to FIGS. 1 and 2. First, the configuration of the earth drill will be explained with reference to FIG.
A crane 1 supports a Kelly bar 4 with a wire rope 2, and a bucket 3 is attached to the lower end of the Kelly bar 4. The Kelly bar 4 is held movable up and down by a Kelly bar drive device 6 installed on the front frame 5, and its upper end is connected to the wire rope 2 via a swivel joint 7 to operate the Kelly bar drive device 6. Therefore, the kelly bar 4 and the bucket 3 can be rotated. In addition, the wire rope 2 is hung on a sheave 9 at the upper end of the boom 8, and is fed out and retracted by the winch 10, thereby lifting the bucket 3.
The descent is beginning to take place. 30 is a depth display device provided in the driver's cab according to the present invention.
The depth display device 30 has a function of resetting the depth display to zero at an arbitrarily determined reference point of the excavation hole 11 and a function of setting the bottom expansion excavation depth, and a detailed example thereof will be described later. . After excavating the excavation hole 11 to a predetermined depth with the bucket 3 as described above, the bucket 3 is replaced with an expanded bottom bucket for excavating the expanded bottom part.

FIG. 2 shows an example of an expanded bottom bucket tote 60 according to the present invention. Reference numeral 61 denotes a case with an opening on the bottom, and has a square hole boss 62 connected to the Kelly bar 4 in the center of the upper part, and an opening in the side part for introducing earth and sand excavated by the expanding blade 63 into the case 61. A section 64 is provided. Reference numeral 65 denotes a bottom cover that is attached to the bottom of the case 61 so as to be openable and closable by a hinge 66, and the bottom cover has a downwardly convex conical shape, and the conical part is provided with a drilling hole as shown in FIG. Opening 65 with butterfly valve 67 for roughening the bottom 11a
A and an edge 65b are provided, and no cutter for digging is provided. Expanding wing 63
is provided on the side surface of the case 61, and is attached to be opened and closed about a hinge 68 by an actuator such as a hydraulic cylinder. Also,
The bottom part 63a of the expanding wing 63 is also not provided with a cutter and is formed horizontally so that the excavated surface of the expanded bottom part is horizontal, and this structure and the hinge 68 are arranged vertically. From Nasu, Expanding Wings 6
3, the bottom portion 63a follows the same trajectory as during excavation work and is closed without leaving a gap with the excavation surface.

In the present invention, using such an excavation device and depth display device 30, excavation of the expanded bottom portion is performed as follows. That is, the operator in the operator's cab lowers the expanded bottom bucket 60 into the excavation hole 11 while monitoring the numerical value displayed on the depth display device 30. This descent is carried out by a free hole up to the vicinity of the bottom-expanding excavation depth, and from there, the brake is applied to slowly descend to the excavation hole bottom 11a. When it is confirmed by the depth display device 30 that the excavation depth of the expanded bottom portion has been reached, the expanded wings 63 of the expanded bottom bucket 60 are rotated while being expanded to excavate the expanded bottom portion. At this time, since the enlarged side portion 63a of the enlarged wing 63 does not have a cutter, it does not dig in the vertical direction. An enlarged blade opening/closing detector (not shown) is attached to the expanded bottom bucket 60, and a display (not shown) for displaying the expanded bottom blade opening/closing angle is provided in the operator's cab,
Since the extent to which the opening/closing angle of the expanding blade 63 is changed to make the inside of the case 61 full with earth and sand has been confirmed in advance, the operator can check the opening/closing angle displayed on the display to determine when the case 61 will be full. When the angle is reached, the expansion wings 63 are closed, and the soil is lifted to the ground and discharged.

By repeating these steps, the bottom-expanding portion is excavated. However, slime accumulates at the bottom 11a of the excavation hole while changing the expanded bottom bucket 60, and even though the depth of excavation has not been reached while the bottom expanded bucket 60 is being lowered, the depth display device 3
When the displayed value of 0 stops changing, the expanded bottom bucket 60 is rotated without expanding the expanding wings 63, and the wire rope 2 is let out little by little. As a result, the slime is scooped out by the edge 65b from the opening 65a with a butterfly of the bottom cover 65 and taken into the case 61. and depth display device 30
When the value displayed reaches the bottom expansion excavation depth,
The bucket 60 is rotated while expanding the expansion wings 63 to excavate the expanded bottom portion.

When re-inserting the expanded bottom bucket 60 into the excavation hole 11, if the value displayed on the depth display device 30 at the zero reference point (for example, the depth when the expanded bottom bucket 60 is lowered to the ground is zero) is incorrect, the display Reset the value to zero. Then, by repeating this process several times, the excavation of the expanded bottom portion is completed.

An example of a depth display device 30 and a depth detector suitable for such bottom-expanding excavation will be explained with reference to FIGS. 3 to 9. FIG. 3 shows the overall configuration of the depth detection device including a depth display device 30 installed in the driver's cab, and 13 is the wire rope 2.
14 is a movement direction detector for determining whether the wire rope 2 is being let out or retracted; 15 is a movement direction detector that receives a signal from the movement direction detector 14; This is a discrimination circuit that discriminates whether the wire rope 2 is let out or retracted. 16 is a calculation device that calculates the depth of the excavation tool (bucket 3 or wide-bottomed bucket 60), and 31 is a digital switch that can arbitrarily set the amount of movement of the wire rope 2 per pulse interval of the movement amount detector 13. The arithmetic unit 16 is a unit length setter that is
The depth of the excavating tool is calculated by receiving an on/off type digital signal from the excavator, a signal from the discrimination circuit 15, and a signal from the unit length setting device 31. 20 is a reset button for setting the value of the arithmetic unit 16 to zero in order to clarify the depth reference point.

The indicator for displaying the depth of the excavation tool may be provided with either a digital indicator or an analog indicator, but in this embodiment, a digital indicator that receives a signal from the calculation device 16 and displays a numerical value is used. Total 17
and a digital-to-analog converter 1 that converts the digital signal from the arithmetic unit 16 into an analog signal.
8, and an analog display meter 19 that receives a signal from the digital-analog converter 18 and displays the depth, and during free hole, the analog display meter 19
This makes it possible to recognize the depth, and when the excavation tool is stopped, the digital display meter 17 makes it possible to accurately read the depth.

In addition, in this embodiment, in order to reduce the operator's awareness of the depth of the drilling tool during freehole, a device is provided that issues an alarm when a brake operation is required, that is, just before the drilling tool reaches the bottom of the hole. 2
It is equipped with 5.

To explain the device 25 for issuing the alarm, 32 is a depth setting device for setting an arbitrary depth at the bottom of the hole, and 33 is a depth setting device 33 which is set in consideration of the brake operation based on the depth L set by the depth setting device 32. A comparator 34 which compares whether the depth (L-l) has become shallow by an appropriate depth l receives a signal from the comparator 33 and instructs the lamp 35 to blink when the depth reaches the depth (L-l).
In addition to instructing the buzzer 36 to sound, it is a buzzer/lamp drive circuit that instructs the lamp 35 to turn on when the depth reaches L and also instructs the buzzer 36 to stop.

The configurations of the movement amount detector 13 and the movement direction detector 14 are shown in FIGS. 1, 4, and 5. A ring 50 made of magnetic material is attached to the side surface of the sheave 9 at the tip of the boom 8 on which the wire rope 2 is hung.
be provided integrally. On the outer periphery of the ring 50,
A plurality of permanent magnets 24 are arranged at equal intervals in the circumferential direction and partially embedded. and,
The movement amount detection switches 13a, 13b, which are activated when the permanent magnet 24 approaches, and the movement direction detection switches 14a, 14b are mounted on a non-rotating part near the sheave with a distance between them so as not to contact the permanent magnets. . In this embodiment, the switch 13
A, 13b, 14a, 14b are attached by pivoting the bracket 40 to the shaft 37 of the sheave 9, and fixing a part of the bracket 40 to the screw seat 38 welded to the boom 8 with a bolt 39. ing.

As described above, if the permanent magnet 24 is embedded in the ring 50 made of magnetic material and the switch is operated by the permanent magnet 24, the magnetic field is generated only in the vicinity of the permanent magnet 24.
can be mounted in close proximity to each other, and the switch opening/closing response speed by the permanent magnet 24 is fast, and a response of up to 1000 CPS is possible, so a detection device with high detection accuracy can be realized. In order to obtain higher detection accuracy, permanent magnets 24 are arranged in two rows on the outer periphery of a ring 50 provided on one side of the sheave 9. The switches 13a and 13b for detecting the amount of movement are arranged in different columns, and when the switches 13a and 13b are on one permanent magnet 24 in one column, the switches 13b and 13b are arranged in different columns.
13a is attached to the bracket 40 so as to be located between the two permanent magnets in the other row.
Therefore, as shown in FIG.
3b means that the switches 13a and 13b are operated alternately by wrapping the operating time _T1 , and the total number of pulses obtained by operating the switches 13a and 13b becomes a signal indicating the amount of movement of the wire rope.

On the other hand, the switches 14a and 14b constituting the moving direction detector 14 are mounted on the bracket 40 so that one of them operates earlier than the other depending on the direction of rotation of the sheave 9. That is, when the sheave 9 rotates clockwise (wire rope payout direction) in FIG. 4, one switch 14 is turned off as shown in FIG. 7A.
The other switch 14b operates with a delay with respect to the operation of switch a, and after a time lapse of _T2 , switch 14b
The operation of a stops. When the sheave 9 rotates in the counterclockwise direction (wire rope retracting direction) in FIG. 4, as shown in FIG. 7B, contrary to A, the switch 14a operates with a delay with respect to the operation of the switch 14b, and T After lapse of time ₂ , switch 14b
operation stops. Such a switch 14a,
The moving direction of the wire rope 2 is determined depending on which of the wire ropes 14b is activated first.

Therefore, the discrimination circuit 15 determines whether the operations of the switches 14a and 14b overlap in time, compares which switch operates faster, and changes the output signal based on the comparison result. It's summery.

Further, the arithmetic device 16 includes an integrating circuit 16a and an arithmetic circuit 16b, as shown in FIG. Each time a pulse from the quantity detector 13 is applied, 1 is added to the value stored up to that point.On the other hand, when the output signal of the discrimination circuit 15 is indicative of wire rope renormalization, the pulse is It is configured to perform an operation of subtracting 1 each time it is added. Note that the discrimination circuit 15 incorporates a pulse chattering prevention circuit having a large specific number. The calculation circuit 16b receives the value of the wire rope movement amount s per pulse set by the unit length setting device 31 and performs calculation to convert the value of the integration circuit 16a into the depth of the excavation tool. be. The depth L is calculated using the following formula.

L=(p×n×s)/m where, p: Amount of pulse generation per rotation of sheave 9 n: Amount of rotation of sheave 9 s: Amount of wire rope movement per one pulse, s
= πD/p (D: Pitch circle of sheave 9...see Figure 4) m: Wire rope multiplier In addition, the digital display 17 and analog display 19 that display the calculated values are zero. With respect to the scale position, set the wire rope 2's unwinding direction as negative (-) and the retracting direction as positive (+).
It is now displayed as . Normally, the value is set to zero when the excavating tool 3, 60, such as a bucket, is located on the ground surface, so the depth of the excavated hole 11 is indicated as -, and the height when the excavating tool is lifted above the ground is indicated as +. Therefore, the display range of the analog display meter 19 is -
It is set wider.

As shown in FIG. 9, the digital display meter 17 and the analog display meter 19 are installed on the same panel surface of one case 21, and the case 21 is
As shown at 30 in the figure, the depth display device is installed in the instrument panel of the driver's cab. Also, case 2
1 includes a power on switch 22 and a power lamp 2.
3, the reset button 20, and the depth setting device 3.
2, a lamp 35, and a buzzer 36 are installed, and the arithmetic unit 16, discrimination circuit 15, digital-to-analog converter 18, and unit length setting device 3 are installed.
1. The comparator 33 and the buzzer/lamp drive circuit 34 are built into the case 21.

The operation of this depth detection device will be explained. When the wide-bottom bucket cart 60 is lowered by free hole operation to excavate the bottom part of the excavation hole 11 with the bottom-expanding bucket cart 60, the operating time relationship of the switches 14a and 14b of the movement direction detector 14 is as shown in FIG. 7A. Because of the relationship shown in FIG.
6a is an operation of increasing the value by a (-) value using a pulse from the movement amount detector 13 ((-) addition operation)
The arithmetic circuit 16b converts the integrated value into a depth, and the digital value is displayed on the digital display 17, and at the same time, the analog quantity obtained by the digital-to-analog converter 18 is displayed on the analog display 19. Ru. In this case, the value displayed on the digital display meter 17 fluctuates rapidly and is difficult to read, but the depth can be read using the analog display meter 19. Therefore, when the robot approaches the hole bottom 11a, the brake can be applied to stop the robot and the robot can land slowly on the hole bottom 11a. That is, whether or not the hole has approached the bottom 11a can be determined by setting the previous excavation depth in the depth setting device 32.
The lamp 35 flashes and the buzzer 36 starts sounding at a depth that is shallower than this by a preset depth l, so it can be determined. Furthermore, when the hole bottom 11a is reached, the lamp 35 turns on and the buzzer 36 stops sounding.

When the wide-bottom bucket tote 60 is pulled up to the ground, the operating time relationship of the switches 14a and 14b of the moving direction detector 14 is as shown in FIG. 7(B), so the discrimination circuit 15 integrates the signal indicating renormalization circuit 16
In order to add the value to a, the integration circuit 16a performs an operation of subtracting the value by a (-) value ((-) subtraction operation) using a pulse from the movement amount detector 13.

Normally, the zero reference point for depth is placed on the ground (G/L), but when the expanded bottom bucket 60 is pulled up from the bottom of the hole and passes through the zero reference point, the internal calculation is a (-) subtraction operation. However, both the digital display meter 17 and the analog display meter 19 apparently perform a (+) addition operation. For example, this is an absolute value
The voltage value when a pulse equivalent to 100m is generated is
If it is 10V, if you set the base voltage value to 2V without returning it to zero V when you press the reset button 20, the voltage will be 0V at a depth of (+) 20m, and a voltage of 0V at a depth of (-) 80m.
A voltage of 10V is generated, and the above-mentioned display becomes possible.

In addition, if the zero reference point of the depth is set on G/L, for example, when the expanded bottom bucket 60 is lowered to the ground with the wire rope 2 stretched, the value displayed on the digital display 17 will be the same as that of the wire rope 2 and sheave 9. It is checked to see if it has gone awry due to slipping, and if an error has occurred, the reset button 20 is pressed to reset the arithmetic unit 16.

Although the present invention has been described above with reference to embodiments, in the present invention, a rotary encoder, an optical sensor, or the like may be used as the depth detector. Also,
In the embodiment, an example has been described in which the bucket is lowered by free-hauling, but in order to further improve the detection accuracy, it may be lowered by powered lowering. Furthermore, a signal from the buzzer/lamp drive circuit 34 is connected to the hydraulic motor drive electric circuit so as to stop the hydraulic motor (not shown) that drives the winch 10 when the winch 10 is lowered by power descent and reaches a set depth. An automatic stop circuit may also be configured.

(Effects of the present invention) As described above, the method for expanding the bottom by the earth drilling method of the present invention provides a depth display device that has the function of resetting the depth display to zero at an arbitrarily determined reference point in the excavation hole. Then lower it into the excavation hole while monitoring, and when it is confirmed by the depth display device that the depth of excavation of the expanded bottom part has been reached, the expanded bottom part excavation device is rotated while expanding the enlarged wings of the bottom expanded part excavation device to excavate the expanded bottom part,
This is a method for excavating the expanded bottom section by repeating the process of taking excavated soil into the case of the bottom expanding section excavation device, closing the expansion wings, pulling it up to the ground, and discharging the soil. This becomes a problem when construction is performed using the earth drill method. The important point is whether the expansion blade can be expanded repeatedly at the same depth.The expansion bucket can be lowered while monitoring the depth of expansion hole construction using a depth display device that starts from the zero reference point at G and L. It can be solved by doing. That is, according to the method of the present invention, since the expanded bottom portion is excavated while checking the excavation depth, excavation can be performed at the same depth, and excavation in the vertical direction can be prevented. In addition, if the numerical value displayed on the depth display device stops changing while the bottom-expanding section excavation device is being lowered and the bottom-expanding section excavation depth has not been reached, the expansion blades may be rotated without expanding. Slime deposited in the excavation hole is taken into the excavation hole through the opening of the bottom cover, and the excavation is carried out to the depth of the expanded bottom part, which prevents swinging due to lifting of the bucket, and allows the correct pile shape to be obtained, increasing the reliability of the pile. It has a remarkable effect on improving sexual performance.

Furthermore, the bottom-expanding excavation equipment using the earth drilling method of the present invention is installed in the operator's cab, and has a function of resetting the depth display to zero at an arbitrarily determined reference point in the drilling hole and a function of setting the bottom-expanding excavation depth. Equipped with a depth display device, it is possible to correct discrepancies in the depth display value and excavate the bottom expansion section to an accurate depth at all times.In addition, by issuing an alarm or automatically stopping when the depth is near the set depth, excavation can be performed at the set depth. It is easy to stop the descent reliably,
The burden on the operator can be reduced. In addition, since there are no cutters on the bottom cover and the underside of the expansion wing, the slime at the bottom of the excavation hole can be disposed of, but since it does not dig in the vertical direction, it is possible to construct piles with even higher reliability. This has the effect of

[Brief explanation of drawings]

Fig. 1 is an overall side view of an earth drill to which the present invention is applied, Fig. 2 is a diagram showing an example of an expanded bottom bucket of the present invention for constructing an expanded bottom pile, and Fig. 3 is a depth display used in the present invention. A block diagram showing an example of the device; FIG. 4 is a layout diagram showing an example of a wire rope movement amount detector and a movement direction detector used in the depth display device; FIG. 5 is a sectional view taken along line II in FIG. 4; 6th
The figure is a pulse waveform diagram explaining the operation of the movement amount detector, FIG. 7 is a pulse waveform diagram explaining the operation of the movement direction detector, and FIG. 8 is a pulse waveform diagram explaining the operation of the movement direction detector. A block diagram showing a configuration example, FIG. 9 is an external view of the display section of the depth display device in the present invention,
FIG. 10 is a sectional view showing the bottom cover of the expanded bottom bucket of FIG. 2. 4...Keriba, 11...Drilling hole, 17...Digital display meter, 19...Analog display meter, 20...
...Reset button, 30...Depth display device, 32
...Depth setting device, 60...Expanding bucket, 61...
...Case, 63...Enlarged wing, 63a...Bottom part,
64...opening, 65...bottom cover, 65a...opening with butterfly, 65b...edge, 66...hinge.

Claims (1)

[Scope of Claims] 1. A case with an opening at the bottom that is connected to the Kelly bar and rotated, and an opening that is attached to the bottom of the case so that it can be opened and closed by a hinge, has a conical shape that is convex downward, and has an opening with a butterfly valve. A bottom-expanding drilling device for a bottom-expanding pile, which is equipped with a bottom cover having an edge, an expanding wing for opening and closing an opening provided on the side surface of the case, and a means for opening and closing the expanding wing, can be installed at any point in the excavation hole. It is lowered into the excavation hole while being monitored by a depth display device that has a function of resetting the depth display to zero at a predetermined reference point, and when it is confirmed by the depth display device that the depth of the bottom expansion section has been reached, the bottom expansion section is lowered. The expansion blades of the excavation device are rotated while being expanded to excavate the expanded bottom part, and the excavated soil is taken into the case of the bottom expansion part excavation device, and then the process of closing the expansion blades, pulling it up to the ground, and discharging the soil is repeated. If the numerical value displayed on the depth display device stops changing even though the bottom-expanding excavation depth has not been reached while the bottom-expanding section is being excavated and the bottom-expanding section excavation device is being lowered, A method for excavating a bottom hole using an earth drilling method, characterized in that the slime deposited in the hole is taken in from the opening of the bottom cover by rotating the expander blades without expanding, and the slime is dug to the bottom depth of the bottom cover. 2. A case with an opening at the bottom that is connected to the Kerry bar and rotated, and a bottom lid that is attached to the bottom of the case so that it can be opened and closed by a hinge, has a conical shape convex downward, and has an opening with a butterfly valve and an edge. , an enlarged wing for opening and closing an opening provided on a side surface of the case, and means for opening and closing the enlarged wing;
A depth display device is provided in the operator's cab and has a function of resetting the depth display to zero at an arbitrarily determined reference point in the excavation hole and a function of setting the depth of excavation of the expanded bottom section. A bottom-expanding hole drilling device using the earth drilling method, characterized in that no cutter is provided at the bottom of the wing.