JP2009108588A - Earth drill - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an earth drill which is equipped with a means for detecting the degree of opening of an enlarged bottom blade, enabling the accurate detection of the quantity of hydraulic oil, supplied to a cylinder, by a simple structure and enabling a sure grasp of the degree of the opening of the enlarged bottom blade during the excavation of an enlarged bottom hole. <P>SOLUTION: First flow-rate detecting means 43d and 43e for detecting a flow rate of the hydraulic oil supplied to the cylinder 27 are provided in a hydraulic oil channel on the side of a hydraulic oil supply source with respect to a rotary joint 33; the rotary joint is provided with a drain channel 42f for taking out only the drain of the hydraulic oil supplied to the cylinder; a second flow-rate detecting means 43f for detecting the flow rate of the hydraulic oil flowing through the drain channel is provided; and a computing means 44 for computing the degree of the opening of the enlarged bottom blade on the basis of the flow rate of the hydraulic oil, detected by the first flow rate detecting means, and that of the hydraulic oil, detected by the second flow rate detecting means, is provided. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an earth drill, and more particularly, to an earth drill provided with an opening detecting means for detecting the opening of a bottom wing when the bottom of an excavation hole is expanded with a bottom expansion bucket.

A bottom expansion bucket is attached to the lower end of the kelly bar suspended from the main body of the earth drill, and the kelly bar is rotated by the kelly bar driving device, and the hydraulic oil is supplied from the hydraulic oil supply source to the cylinder for expanding and reducing the bottom expansion blade via the rotary joint. Then, expanding the bottom hole is performed at the bottom of the excavation hole by expanding and contracting the cylinder to expand the bottom expansion blade. When excavating the bottom of the excavation hole with the expansion bucket, it is necessary to detect the opening of the expansion wing, so in the hydraulic oil flow path outside the excavation hole upstream of the rotary joint (on the hydraulic oil supply side) In addition, a flow rate detection means is provided, and a calculation means for calculating the opening of the bottom wing based on the flow rate detected by the flow rate detection means is known (see, for example, Patent Document 1).
No. 7-541

  However, in the case where the flow rate detection means is provided on the upstream side of the rotary joint, when the amount of hydraulic oil leaking from the rotary joint increases, the amount of hydraulic oil actually supplied to the cylinder and the operation detected by the flow rate detection means The difference from the oil flow rate becomes large, and an error may occur between the opening of the bottom expansion wing calculated by the calculation means and the actual opening of the bottom expansion wing, and the flow rate is downstream of the rotary joint. The opening degree of the bottom expansion blade can be accurately obtained by providing detection means or directly detecting the amount of expansion / contraction of the cylinder. In this case, however, as described in Patent Document 1, Since it is necessary to perform wireless communication for transmission and reception of the flow rate, there are problems such as a problem in reliability of the detection apparatus and a complicated apparatus configuration.

  Therefore, the present invention is capable of accurately detecting the amount of hydraulic oil supplied to the cylinder with a simple structure and capable of accurately knowing the opening degree of the bottom expansion blade while excavating the bottom expansion hole. It aims at providing the earth drill provided with the detection means.

  In order to achieve the above object, an earth drill according to the present invention is provided with a bottom expansion blade of a bottom expansion bucket mounted on and attached to a lower end portion of a kelly bar that is driven and rotated by a kelly bar driving device from a hydraulic oil supply source via a rotary joint. In an earth drill that expands and contracts the bottom wing by expanding and contracting the cylinder with hydraulic oil supplied to a cylinder for expansion and contraction, and expands the bottom expansion hole at the bottom of the excavation hole, the hydraulic oil supply source side from the rotary joint A first flow rate detecting means for detecting a flow rate of the hydraulic oil supplied to the cylinder is provided in the hydraulic oil route, and a drain path for taking out only the drain of the hydraulic oil supplied to the cylinder is provided in the rotary joint. In addition, a second flow rate detecting means for detecting the flow rate of the hydraulic oil flowing through the drain path is provided.

  The first flow rate detecting means may be provided in one or both of a path for supplying hydraulic oil to the expansion side of the cylinder and a path for supplying hydraulic oil to the contraction side of the cylinder. Furthermore, the earth drill according to the present invention calculates the opening of the bottom wing based on the flow rate of the hydraulic oil detected by the first flow rate detection unit and the flow rate of the hydraulic oil detected by the second flow rate detection unit. It is characterized by having a calculation means.

  According to the earth drill of the present invention, the amount of hydraulic oil supplied to the cylinder for expanding / contracting the bottom expansion blade can be accurately known by the first flow rate detection means and the second flow rate detection means. The amount of expansion and contraction of the cylinder that expands and contracts can be accurately detected, and the bottom expansion blade can be reliably opened to a predetermined opening. Therefore, it is possible to excavate the bottom expansion hole at the bottom of the excavation hole efficiently and accurately.

  1 to 5 show a first embodiment of the earth drill according to the present invention. FIG. 1 is a circuit diagram showing a main part of a hydraulic oil supply system. FIG. 2 is a cross-sectional view showing a main part of a rotary joint. FIG. 3 is a side view of an earth drill with a bottom expansion bucket attached to the lower end of the kelly bar, FIG. 4 is a side view of the earth drill showing a state in which the bottom expansion blade is opened and the bottom expansion hole is being expanded, and FIG. It is a front view which shows an example of a bucket.

  First, the ground drill wraps a wire rope 15 from a winch 14 around a sheave 13 rotatably supported on a tip of a boom 12 provided on a self-propelled main body 11, and the tip of the wire rope 15 is wound around the tip of the wire rope 15. The kelly bar 17 is rotatably suspended via the swivel joint 16 and the kelly bar 17 is moved up and down by the winch 14. Further, a kelly bar drive device 19 is provided at the tip of the arm 18 supported by the main body 11 so that the kelly bar 17 can be moved up and down. The kelly bar drive device 19 rotates the kelly bar 17. It is composed. Furthermore, a rotary table 20 that rotates integrally with the kelly bar 17 but does not move up and down is provided at the lower part of the kelly bar driving device 19. A kelly bar 17 that protrudes downward from the rotary table 20 is provided at the lower end of the kelly bar 17. An expanded bottom bucket 21 that rotates integrally with 17 and moves up and down is mounted.

  The bottom expansion bucket 21 is provided with a disc-shaped bottom cover 24 for discharging the excavated earth and sand at the lower end of a cylindrical main body 23 having an outer diameter corresponding to the inner diameter of the excavation hole 22, and a main body portion. 23 and a bottom lid 24 are provided with a plurality of bottom expansion wings 25 formed in a substantially triangular shape having a wide lower portion and a narrow upper portion, which can be opened and closed. The end is pivotally supported on the main body 23 by a hinge having an axis in the vertical direction, and the tip end side having the excavating blade 26 is formed to open and close. Further, when the bottom expansion blade 25 is closed, it has the same outer diameter as the inner diameter of the excavation hole 22, and when it is opened, the lower end of the tip protrudes greatly, and the trajectory of the excavation blade 26 at the time of rotation forms a conical surface.

  The main body portion 23 is provided with a bottom expansion blade expansion / contraction mechanism including a cylinder 27, a slider 28, and a link 29 for opening and closing the bottom expansion blade 25, and a high pressure hydraulic oil is supplied to the expansion side of the cylinder 27 to provide a cylinder. By expanding the rod and pushing the slider 28 downward, the bottom wing 25 can be opened from the slider 28 via the link 29, and high pressure hydraulic oil is supplied to the contraction side of the cylinder 27 to remove the cylinder rod. By shortening and pulling the slider 28 upward, the bottom expanded blade 25 can be closed via the link 29.

  The hydraulic oil is supplied to the cylinder 27 by a pair of hydraulic hoses 31a and 31b wound around the hose reel 30 disposed on the rotary table 20, and the hydraulic hoses 31a and 31b are wound around the hose reel 30. The hose reel 30 is rotationally driven by the hydraulic motor 32. Since the hose reel 30 and the hydraulic motor 32 are disposed on the rotary table 20 that rotates integrally with the kelly bar 17, an earth drill main body hydraulic source (see FIG. 5) that is a hydraulic oil supply source provided in the main body 11 of the earth drill. A rotary joint 33 is provided between the kelly bar driving device 19 and the rotary table 20 in order to supply hydraulic oil to the cylinder 27 and the hydraulic motor 32 from (not shown).

  As shown in FIG. 2, the rotary joint 33 is fixed to a non-rotating portion of the kelly bar driving device 19 in order to supply or collect hydraulic oil from the non-rotating state kelly bar driving device 19 side to the rotating table 20 side. The outer cylinder 34 and the inner cylinder 35 which is fixed to the rotating turntable and rotates coaxially within the outer cylinder 34 are connected to the ground drill main body hydraulic power source on the outer surface of the outer cylinder 34. A plurality of connectors 36a to 36g to which a plurality of hydraulic hoses 31 (see FIG. 3 and FIG. 4) are connected are provided, and the inner peripheral surface of the outer cylinder 34 communicates with the connectors 36a to 36g, respectively. Hydraulic oil flow paths 37a to 37g are provided, and seal rings 38 are provided between the flow paths 37a to 37g for suppressing oil leakage (leakage). Further, inside the inner cylinder 35, there is a hydraulic oil passage 39 for supplying hydraulic oil to the hydraulic hoses 31 a and 31 b via the hose reel 30 and supplying hydraulic oil to the hydraulic motor 32. A hydraulic hose connector 40 that is connected to the hose reel 30 and the hydraulic motor 32 is provided at a protruding portion of the inner cylinder 35 that is disposed at a predetermined interval in the circumferential direction and protrudes downward from the outer cylinder 34.

  Further, inside the outer cylinder 34, a hydraulic oil passage 37d through which high-pressure hydraulic oil flows when the cylinder 27 is extended, and a hydraulic oil passage 37e through which high-pressure hydraulic oil flows when the cylinder 27 is shortened. Is provided with a cylinder drain recovery flow path 41.

  The cylinder drain recovery channel 41 includes annular drain recovery grooves 41a and 41b provided on both sides of the hydraulic oil channel 37d and a hydraulic oil channel 37f provided corresponding to the cylinder drain recovery connector 36f. The hydraulic fluid leaking between the outer cylinder 34 and the inner cylinder 35 through the hydraulic oil flow path 37d and passing through the seal rings 38 on both sides during the cylinder extension operation is recovered by the drain recovery grooves 41a and 41b. Then, the oil is sent from the cylinder drain collection passage 41 to the cylinder drain passage 42f connected to the connector 36f via the hydraulic oil passage 37f and the cylinder drain collection connector 36f. Further, the hydraulic oil leaking from the hydraulic oil passage 37e through the seal ring 38 on both sides during the cylinder shortening operation and leaking between the outer cylinder 34 and the inner cylinder 35 to one drain collecting groove 41b and the hydraulic oil passage 37f The hydraulic oil recovered in the drain recovery groove 41b is joined with the hydraulic oil recovered in the hydraulic oil flow path 37f through the cylinder drain recovery flow path 41, and the cylinder drain recovery connector is connected from the hydraulic oil flow path 37f in the same manner as described above. It sends out to the cylinder drain path 42f via 36f.

  Further, the low-pressure hydraulic oil after the hydraulic motor 32 is rotationally driven is discharged between the hydraulic oil passage 37b for supplying hydraulic oil for rotationally driving the hydraulic motor 32 and the drain recovery groove 41a. Even if the hydraulic oil for rotating the hydraulic motor 32 leaks between the outer cylinder 34 and the inner cylinder 35, the leaked hydraulic oil is used as the hydraulic oil flow path 37c. The oil is collected in the flow path 37c so that hydraulic oil for the hydraulic motor does not flow into the drain collecting groove 41a.

  As shown in FIG. 1, when the cylinder 27 is extended, the cylinder extension side path 42d for supplying high-pressure hydraulic oil from the connector 36d of the rotary joint 33 through each flow path has a cylinder extension side. An extension-side first flow rate detector 43d that detects the flow rate of hydraulic fluid flowing through the path 42d is provided, and when the cylinder 27 is shortened, high-pressure hydraulic fluid is supplied from the connector 36e of the rotary joint 33 through each flow path. The cylinder shortening side path 42e to be supplied is provided with a shortening side first flow rate detector 43e for detecting the flow rate of the hydraulic oil flowing through the cylinder shortening side path 42e, and the cylinder drain path connected to the cylinder drain collecting connector 36f. 42f is provided with a second flow rate detector 43f for detecting the flow rate of the hydraulic oil flowing through the cylinder drain passage 42f. It is.

  The flow rate signals detected by the flow rate detectors 43d, 43e, and 43f are respectively transmitted to the calculation unit 44 by wired transmission using signal lines, and calculation processing is performed in the calculation unit 44. Based on each flow rate signal, the cylinder 27 The amount of expansion / contraction of the bottom wing 25 is calculated from the amount of expansion / contraction. For example, when the cylinder 27 is extended, the hydraulic oil calculated based on the flow rate signal from the second flow rate detector 43f from the hydraulic oil supply amount calculated based on the flow rate signal from the extension side first flow rate detector 43d. By subtracting the drain amount, the actual amount of hydraulic oil supplied to the expansion side of the cylinder 27 without leaking at the rotary joint 33 can be accurately calculated. Therefore, by obtaining the relationship between the supply amount of the high-pressure hydraulic oil to the cylinder 27 and the opening degree of the bottom expanding blade 25 in advance, the opening degree of the bottom expanding blade 25 is determined based on the flow rate signals from both the flow rate detectors 43d and 43f. Can be calculated accurately.

  The first flow rate detectors 43d and 43e are preferably provided in both the cylinder extension side passage 42d and the cylinder shortening side passage 42e, so that the opening degree of the bottom expansion blade 25 can be calculated more accurately and reliably. Even if the first flow rate detector is provided only in one of these paths, preferably the cylinder extension side path 42d, the opening degree of the bottom expanded blade 25 can be calculated. Furthermore, by providing a first flow rate detector in each of the paths 42d and 42e and comparing the detected flow rates of both, it is possible to ensure this even when the bottom expansion blade 25 is expanded or contracted due to the resistance of earth and sand during the bottom expansion excavation. In addition to being able to detect, it is also possible to determine whether or not the hydraulic oil is leaking at any place other than the hydraulic oil recovered from the rotary joint 33 to the cylinder drain path 42f.

  By accurately calculating the opening degree of the bottom expanding blade 25 in this way, a desired bottom expanding hole 22a can be accurately constructed at the bottom of the excavation hole 22, and the mud in the excavation hole 22 can be submerged during the bottom expansion excavation. Regardless of wireless communication using a detector or a wireless transmitter that has been submerged, a flow rate detector is provided in the hydraulic fluid path that remains on the ground side even during bottom expansion excavation, and signals are transmitted by wired transmission using signal lines. By transmitting and receiving, the device configuration can be simplified and the reliability can be improved. Further, by detecting the drain amount of the hydraulic oil with the second flow rate detector 43f, it is possible to reliably know the damage or the deterioration state of the seal ring 38.

  Further, when the bottom expansion hole 22a is to be constructed in a plurality of times, the earth and sand excavated by opening the bottom expansion blade 25 to a preset opening degree is taken in the state where the bottom expansion blade 25 is closed and taken into the bottom expansion bucket 21. 17 is raised and discharged from the expanded bucket 21 to a predetermined location outside the excavation hole 22, but when excavated with the expanded wing 25 wide open, a large amount of earth and sand enters inside the expanded wing 25. The bottom wing 25 cannot be closed, and the Keriba 17 cannot be raised. Further, when excavation is performed in a state where the opening degree is small, the excavated earth and sand can be discharged, but even if the bottom expansion excavation is performed a predetermined number of times, the predetermined bottom expansion hole 22a cannot be constructed. Therefore, by accurately knowing the opening degree of the bottom expanding blade 25, it is possible to efficiently excavate and discharge the earth and sand according to the sediment storage capacity of the bottom expanding bucket 21, and efficiently and accurately perform the bottom expanding excavation of the bottom expanding hole 22a. Can do.

  6 and 7 show a second embodiment of the earth drill according to the present invention. FIG. 6 is a circuit diagram showing the main part of the hydraulic oil supply system, and FIG. 7 is a cross-sectional view showing the main part of the rotary joint. is there. In the following description, the same components as those of the earth drill shown in the first embodiment are designated by the same reference numerals, and detailed description thereof is omitted.

  In this embodiment, in the outer cylinder 34 of the rotary joint 33 formed in the same manner as described above, the upper side of the hydraulic oil passage 37d for extending the cylinder 27 (the hydraulic oil passage 37c side for discharging the hydraulic oil from the hydraulic motor 32). ) Is provided with an extension side drain recovery connector 51, an annular extension side drain recovery groove 52a communicating with the extension side drain recovery connector 51, and an annular extension side drain recovery groove 52b provided on the lower side of the hydraulic fluid passage 37d. Are communicated by the extension side drain recovery flow path 52, and the hydraulic oil leaked between the outer cylinder 34 and the inner cylinder 35 from the hydraulic oil flow path 37d when the cylinder 27 is extended from the extension side drain recovery connector 51. A shortened side drain recovery connector 54 is provided on the lower side of the hydraulic fluid passage 37e for shortening the cylinder 27, and is formed so as to be drawn out to the extension side drain passage 53. An annular shortened side drain collection groove 55a communicating with the shortened side drain collection connector 54 and an annular shortened side drain collection groove 55b provided on the upper side of the hydraulic oil passage 37e are passed through the shortened side drain collection channel 55. The hydraulic oil leaked between the outer cylinder 34 and the inner cylinder 35 from the hydraulic oil passage 37e when the cylinder 27 is shortened is formed to be extracted from the shortened drain collecting connector 54 to the shortened drain path 56, Drain recovery is performed separately on the expansion side and the shortening side.

  As described above, the cylinder drain paths 53 and 56 for collecting the hydraulic oil leaked between the outer cylinder 34 and the inner cylinder 35 beyond the seal ring 38 are provided on the extension side and the shortening side, and both cylinders are provided. By providing the extension side second flow rate detector 57 and the shortening side second flow rate detector 58 in the drain paths 53 and 56, respectively, and transmitting the flow rate signals detected by both the second flow rate detectors 57 and 58 to the calculation means 44. The opening when the cylinder 27 is extended to expand the bottom wing 25 and the opening when the cylinder 27 is shortened to reduce the diameter of the bottom wing 25 can be accurately calculated. Further, the expansion / contraction direction and angle when the bottom expansion blade 25 is expanded / contracted by an external force can be accurately known.

  As the flow rate detector, any flow rate detector used for detecting the flow rate of this type of hydraulic oil can be used. The flow rate signal is an electric signal corresponding to the flow rate detector used, for example, a rotary encoder. Is output as a pulse signal. The calculation of the opening of the bottom wing from the flow rate signal by the computing means can be easily performed by obtaining the relationship between the flow rate of the hydraulic oil and the opening of the bottom wing in advance. Further, by controlling the ground drill main body hydraulic power source according to the detected flow rate signal or the calculated opening of the bottom expansion blade, the bottom expansion blade can be automatically expanded or contracted. In addition, operations such as raising / lowering and rotation of the kelly bar, driving of the hose reel by the hydraulic motor, and expansion / contraction switching of the expanded wing are performed in the same manner as before by appropriately switching the supply state of the hydraulic oil from the ground drill main body hydraulic power source. Can do.

It is a circuit diagram which shows the principal part of the hydraulic-oil supply system | strain in the 1st example of an earth drill of this invention. It is sectional drawing which similarly shows the principal part of a rotary joint. It is a side view of the earth drill which attached the bottom expansion bucket to the lower end part of Keriba. It is a side view of the earth drill which shows the state in which the bottom expansion blade of the bottom expansion bucket is opened and the bottom expansion hole is being expanded. It is a front view which shows an example of an expanded bucket. It is a circuit diagram which shows the principal part of the hydraulic-oil supply system | strain in the 2nd example of the earth drill of this invention. It is sectional drawing which similarly shows the principal part of a rotary joint.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... Main body, 12 ... Boom, 13 ... Sheave, 14 ... Winch, 15 ... Wire rope, 16 ... Swivel joint, 17 ... Kelly bar, 18 ... Arm, 19 ... Kelly bar drive, 20 ... Rotary table, 21 ... Expanded bucket, DESCRIPTION OF SYMBOLS 22 ... Excavation hole, 22a ... Expanding hole, 23 ... Main part, 24 ... Bottom cover, 25 ... Expanding blade, 26 ... Excavation blade, 27 ... Cylinder, 28 ... Slider, 29 ... Link, 30 ... Hose reel, 31, 31a 31b ... Hydraulic hose, 32 ... Hydraulic motor, 33 ... Rotary joint, 34 ... Outer cylinder, 35 ... Inner cylinder, 36a-36g ... Connector, 37a-37g ... Hydraulic oil flow path, 38 ... Seal ring, 39 ... Hydraulic oil Flow path, 40 ... Connector, 41 ... Cylinder drain recovery flow path, 41a, 41b ... Drain recovery groove, 42d ... Cylinder extension side path, 42e ... Cylinder short Side path, 42f ... Cylinder drain path, 43d ... Extension side first flow rate detector, 43e ... Shortening side first flow rate detector, 43f ... Second flow rate detector, 44 ... Calculation means, 51 ... Extension side drain recovery connector, 52 ... Extension side drain recovery flow path, 52a, 52b ... Extension side drain recovery groove, 53 ... Extension side drain path, 54 ... Short side drain recovery connector, 55 ... Short side drain recovery flow path, 55a, 55b ... Short side drain Recovery groove 56 ... Short side drain path 57 ... Extension side second flow rate detector 58 ... Short side second flow rate detector

Claims (3)

  The bottom expansion blade of the bottom expansion bucket attached to the lower end of the rotating kelly bar driven by the Keriba drive device is expanded and contracted with the hydraulic oil supplied from the hydraulic oil supply source to the cylinder for expanding and contracting the bottom expansion blade through the rotary joint. In the earth drill that expands and contracts the bottom expanded wing to expand the bottom expanded hole at the bottom of the excavation hole, the hydraulic oil supplied to the cylinder from the rotary joint to the hydraulic oil path on the hydraulic oil supply source side The first flow rate detecting means for detecting the flow rate of the hydraulic fluid is provided, the drain joint is provided in the rotary joint for extracting only the drain of the hydraulic fluid supplied to the cylinder, and the flow rate of the hydraulic fluid flowing through the drain route is detected. 2. An earth drill characterized by providing a flow rate detecting means.   The first flow rate detecting means is a flow rate detector provided in one or both of a path for supplying hydraulic oil to the expansion side of the cylinder and a path for supplying hydraulic oil to the contraction side of the cylinder. The earth drill according to claim 1, wherein:   Computation means is provided for calculating the opening of the bottom wing based on the flow rate of hydraulic oil detected by the first flow rate detection means and the flow rate of hydraulic oil detected by the second flow rate detection means. The earth drill according to claim 1 or 2.

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