Double drill head

Abstract

To provide a double drill head having both of a percussion drill head and a rotary drive, and capable of efficiently using driving power and attaining a compact and light weight structure.SOLUTION: A double drill head comprises: a percussion drill head 4 having a hammer sub 8 transmitting striking power and torque to a boring rod, a driving motor 10 rotating the hammer sub 8 and an elastic member 13 provided around the hammer sub 8 and mitigating the striking power of the hammer sub 8; a penetrating type rotary driver 5 having a rotatable spindle 21 for penetrating the boring rod and a chuck piece 28 for gripping and releasing the boring rod, and a hydraulic chuck cylinder 32 for gripping operation of the chuck piece 28 and assembled in parallel to the percussion drill head 4; and a transmission gear mechanism 38 transmitting torque of the driving motor 10 of the percussion drill head 4 to a rotary drive 6.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a double drill head provided with both a percussion drill head and a rotary drive.

Background Art

[0002] Patent Document 1 discloses, as a conventional device, a ground improvement machine that improves the efficiency of excavation by providing both a percussion drill head and a center hole type auger machine on a leader. This ground improvement machine has a structure in which the percussion drill head and the auger machine are coaxially provided on the leader with respect to a lifting frame that can be lifted and lowered on the leader, or two lifting frames are provided in the circumferential direction of the leader, and the percussion drill head is attached to one lifting frame and the auger machine is attached to the other lifting frame.

[0003] In such a conventional device, when a steel pipe pile is set in the auger machine and driven into the ground, and it becomes difficult to drive when encountering hard ground or the like, after removing the steel pipe pile from the auger machine, the boring rod is passed through the auger machine and connected to the percussion drill head. Then, after crushing the hard ground with the percussion drill head, the boring rod is removed, the steel pipe pile is set in the auger machine, and the driving of the steel pipe pile is resumed by the auger machine. Thus, it is possible to use both the auger machine and the percussion drill head with one ground improvement machine, and it is possible to improve the construction efficiency.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In conventional equipment, the auger machine and the percussion drill head are driven separately by their own power sources. This structure, where each component has its own power source, results in a large number of parts, making the overall structure large and heavy. Furthermore, since the auger machine and the percussion drill head each have independent drive sources, one drive source cannot be used to power the other. This results in a problem where the drive force cannot be used efficiently.

[0006] This invention was made in consideration of the problems of such conventional devices, and aims to provide a double drill head that can efficiently utilize driving force and has a compact and lightweight structure by having a percussion drill head and a rotary drive in a combined structure. [Means for solving the problem]

[0007] The present invention provides a percussion drill head comprising a hammer sub that transmits impact force and rotational force to a boring rod, a drive motor that rotates the hammer sub, and an elastic member provided around the hammer sub to mitigate the impact force of the hammer sub. A through-type rotary drive is assembled to the percussion drill head in a side-by-side configuration, comprising a rotatable spindle through which a boring rod passes, a chuck piece for gripping and releasing the boring rod, and a hydraulic chuck cylinder for gripping the chuck piece. The percussion drill head is characterized by comprising a transmission gear mechanism that transmits the torque of the drive motor to the rotary drive.

[0008] In the present invention, the percussion drill head and the through-type rotary drive are mounted to the ground improvement machine in a manner that allows for switching of the drilling position.

[0009] Furthermore, in the present invention, the ground improvement machine comprises a slide table that is movable in the longitudinal direction relative to a guide cell, and a shift table that is movable laterally on the slide table, and the percussion drill head and the through-type rotary drive are characterized in that the drilling position is switched by the lateral movement of the shift table. [Effects of the Invention]

[0010] According to the present invention, a transmission gear mechanism is provided to transmit the torque of the drive motor of the percussion drill head to the rotary drive, thereby rotating the spindle of the rotary drive. As a result, the rotary drive does not require a drive source such as an oil motor for rotation, and a compact and lightweight structure can be achieved. [Brief explanation of the drawing]

[0011] [Figure 1] This is a longitudinal cross-sectional view of a double drill head from Huawei. [Figure 2] This is a longitudinal cross-sectional view showing the connection of a boring rod. [Figure 3] This is a perspective view of a double drill head. [Figure 4] This is a perspective view of a ground improvement machine equipped with a double drill head. [Modes for carrying out the invention]

[0012] Figures 1 to 4 illustrate a double drill head 1 according to one embodiment of the present invention. Figure 1 is a longitudinal cross-sectional view of the double drill head 1 of one embodiment, Figure 2 is a longitudinal cross-sectional view showing the connection of the boring rods, Figure 3 is a perspective view, and Figure 4 is a perspective view of the ground improvement machine.

[0013] As shown in Figures 1 to 3, the double drill head 1 is formed by assembling a percussion drill head 4 and a rotary drive 5 side by side inside the case 2.

[0014] The percussion drill head 4 is a drill head that excavates hard ground by striking and rotating a boring rod 6. In the percussion drill head 4, First The spindle gear 7 is rotatably mounted in the case 2 via a bearing 12, and First A hammer sub 8 is inserted axially (in the vertical direction in the illustrated example) into the spindle gear 7. The hammer sub 8 is inserted into the spindle gear 7 in an engaged state via a pin 9, and First when the spindle gear 7 rotates, the hammer sub 8 rotates.

[0015] A hammer spool 16 is coaxially arranged at the rear end of the hammer sub 8 (Fig. 2). When the hammer spool 16 is struck by a striking mechanism (not shown) composed of a percussion cylinder, an impact force is transmitted to the hammer sub 8 and transmitted to a bit that strikes the ground. Reference numeral 13 is an elastic member composed of a plurality of disc springs. The elastic member 13 is arranged at an intermediate portion in the axial direction of the hammer sub 8 and acts to relieve the impact force of the hammer sub 8. As the elastic member , a coil spring may be used instead of the disc spring

[0016] The percussion drill head 4 includes a drive motor consisting of an oil motor. As shown in Figs. 1 and 2, a counter gear 15 of a counter pinion 14 meshes with a motor pinion 11 of the drive motor 10, and First this First counter gear 15 First meshes with the spindle gear 7. Thus, when the drive motor 10 is rotationally driven, First the spindle gear 7 rotates.

[0017] As shown in FIG. 2, a cleaning swivel 63 having a water supply port 60 and a drain port 61 is connected to the tip of the hammer sub 8. A master coupling 64 is connected to the cleaning swivel 63, and an extension rod 65 is mounted in the master coupling 64. A boring rod 6 composed of an outer rod 6a and an inner rod 6b is connected to the tip of the extension rod 65, and the impact force and rotational force of the hammer sub 8 are transmitted to the boring rod 6, causing the boring rod 6 to strike and rotate to excavate the ground. When excavating the ground, drilling water is supplied from the water supply port 60 to the inner rod 6b of the boring rod 6, and the drilling water containing the slime after excavation is discharged from the drain port 61 through the space between the outer rod 6a and the master coupling 64 and the extension rod 65.

[0018] The rotary drive 5 is a through-type rotary drive having a spindle 21 in which a through hole 20 is formed in the axial direction (in the illustrated example, the vertical direction). The spindle 21 is rotatably attached to the case 2 via a bearing 22 and rotates when a rotational force is transmitted from the percussion drill head 4. The boring rod 6 is inserted into the through hole 20 of the spindle 21, and the boring rod 6 rotates to excavate the ground as the spindle 21 rotates. Such a rotary drive 5 uses a boring rod common to the percussion drill head 4. The spindle 21 is disposed between a cover plate 24 and an end plate 25 attached to both ends of the case 2.

[0019] An opening 23 that opens a part of the spindle 21 is formed in the intermediate portion of the spindle 21 in the axial direction. A plurality of openings 23 are formed along the radial direction of the spindle 21, and a chuck piece 28 of the chuck member 27 is disposed in each opening 23.

[0020] The chuck pieces 28 are positioned in each of the openings 23 of the spindle 21. Chuck springs 29 are attached to the upper and lower ends of the chuck pieces 28, and the chuck pieces 28 are attached to each of the openings 23 by the chuck springs 29. The chuck pieces 28 operate to grip and release the boring rod 6 that passes through the spindle 21.

[0021] In addition to the chuck piece 28, the chuck member 27 includes a slide ring 30, a slide plate 31, and a hydraulic chuck cylinder 32. The slide ring 30 is formed in a cylindrical shape that extends in the axial direction and is provided to cover the outside of all chuck pieces 28. The inner surface of the slide ring 30 and the outer surface of the chuck pieces 28 are in contact at tapered surfaces 33. When the slide ring 30 moves in one direction (upward in the illustrated example), the chuck pieces 28 are pushed out from the spindle 21 and bite into the boring rod 6, gripping the boring rod 6. On the other hand, when the slide ring 30 moves in the opposite direction, the pressure on the chuck pieces 28 is released, and the chuck pieces 28 retract due to the spring force of the chuck spring 29, thereby releasing the grip of the boring rod 6 by the chuck pieces 28.

[0022] The slide plate 31 is attached to the tip of the hydraulic chuck cylinder 32 while connected to it. The hydraulic chuck cylinder 32 extends and retracts by hydraulic pressure. As shown in Figures 1 and 2, multiple hydraulic chuck cylinders 32 are arranged around the slide ring 30, and their extension and retraction causes the slide plate 31 to reciprocate in the axial direction, thereby causing the slide ring 30 to reciprocate as a whole. This reciprocating movement of the slide ring 30 causes the boring rod 6 to be gripped and released by the chuck piece 28. A cross roller bearing 34 is positioned between the slide ring 30 and the slide plate 31, so that it can withstand both thrust and radial loads. Since such a chuck member 27 is operated by hydraulics, its operation can be automated.

[0023] The rotary drive 5 described above rotates the spindle 21 due to the rotational force transmitted from the percussion drill head 4, and for this rotation, the torque of the drive motor 10 of the percussion drill head 4 is transmitted to the spindle 21 of the rotary drive 5. The transmission gear mechanism 38 that performs this transmission is It is formed by a motor pinion 11 of the drive motor 10, a first counter gear 15 meshing with the motor pinion 11, a first spindle gear 7 meshing with the first counter gear 15 and rotating the hammer sub 8, a second counter gear 15a meshing with the first spindle gear 7, and a second spindle gear 35 meshing with the second counter gear 15a and rotating the spindle 21.

[0024] As shown in Figures 1 and 2, the rotary drive 5 Second With the spindle gear 35 assembled to the spindle 21 via the key 36, on the percussion drill head 4 side First It meshes with the counter gear 15. In this type of transmission gear mechanism 38, the torque of the drive motor 10 of the percussion drill head 4 is transmitted to the spindle 21 on the rotary drive 5 side, causing the spindle 21 to rotate. Therefore, the rotary drive 5 side does not need a drive source such as an oil motor to rotate the spindle 21.

[0025] Figure 4 shows the ground improvement machine 40 with the double drill head 1 attached. The ground improvement machine 40 consists of a base machine 41 equipped with crawlers 42 for travel and turning, and a power unit 43 which is the power source for driving the entire ground improvement machine 40, including the double drill head 1. Guide cells 44 are erected on the base machine 41. The angle of the guide cells 44 can be adjusted relative to the base machine 41 by an inclined cylinder 45.

[0026] A chain 46 is attached to the guide cell 44 so that it can travel along its length. A feed motor 47 for driving the chain 46 is provided at the rear end of the guide cell 44, and the entire double drill head 1 can move along its length relative to the guide cell 44 by the drive of the feed motor 47. The double drill head 1 consists of a percussion drill head 4 and a rotary drive 5, which are positioned side-by-side in a direction perpendicular to the axial direction of the guide cell 44.

[0027] As shown in Figure 4, a slide table 50 is attached to the chain 46, a shift table 51 is attached to the slide table 50, and a double drill head 1 is attached to the shift table 51. In this case, as shown in Figures 1 and 2, the double drill head 1 is attached to the excavator 40 by attaching the mounting bracket 2a, which is provided on the percussion drill head 4 side of the case 2 of the double drill head 1, to the shift table 51. Driven by the feed motor 47, the chain 46 travels in one direction (upward in the illustrated example) along the length of the guide cell 44, causing the slide table 50 to move in the same direction. This causes the shift table 51 to move together, lifting the entire double drill head 1 and raising the boring rod 6. Conversely, driven by the feed motor 47 in the reverse direction, the chain 46 travels in the opposite direction along the length of the guide cell 44, causing the slide table 50 to move in the same direction, the shift table 51 to move together, the double drill head 1 to move towards the ground, and the boring rod 6 to be fed.

[0028] The shift table 51 is mounted on the slide table 50 so as to be movable laterally. Lateral movement of the shift table 51 is performed by a shift mechanism 52 equipped with a drive means such as a cylinder or an oil motor. The shift mechanism 52 is mounted on the slide table 50, and when the shift mechanism 52 is driven, the shift table 51 moves laterally, changing the position of the double drill head 1 relative to the guide cell 44. As a result, either the percussion drill head 4 or the rotary drive 5 moves to the drilling position along the guide cell 44. In this structure, the drilling position between the percussion drill head 4 and the rotary drive 5 is switched by the lateral movement of the shift table 51 relative to the slide table 50.

[0029] In Figure 4, reference numeral 48 denotes a rod clamp attached to the tip of the guide cell 44, and reference numeral 49 denotes a rod breaker. The rod clamp 48 clamps the boring rod 6 when extending or detaching the boring rod 6, and the rod breaker 49 clamps the boring rod 6 when detaching the boring rod 6 and rotates it by a predetermined angle to loosen the screw connection of the boring rod 6.

[0030] Next, we will describe an example of the coordinated operation between the percussion drill head 4 and the rotary drive 5. In the rotary drive 5, the spindle 21 rotates while the boring rod 6, which has passed through the spindle 21, is gripped by the chuck member 27. This allows a new boring rod 6 to be screwed onto the boring rod already in the ground, thus connecting multiple boring rods 6. With the multiple boring rods 6 connected, the spindle 21 rotates, and the rotary drive 5 is fed forward to excavate the ground. The rotation of the spindle 21 in the rotary drive 5 is achieved by the rotational force of the drive motor 10 on the part drill head 4 side being transmitted via the transmission gear mechanism 38.

[0031] When drilling with the rotary drive 5 encounters hard ground and drilling becomes difficult, the chuck member 27 of the rotary drive 5 releases its grip on the boring rod 6. The entire double drill head 1 then moves upward, causing the rotary drive 5 to retract from the boring rod 6. Subsequently, the shift table 51 is moved laterally, causing the double drill head 1 to move laterally, so that the percussion drill head 4 moves onto the boring rod 6, and the boring rod 6 is connected to the cleaning swivel 63 at the tip of the hammer sub 8, and the hard ground is drilled by the impact, rotation and feeding of the percussion drill head 4. After the drilling of the hard ground is complete, the double drill head 1 is raised and then moved laterally, causing the rotary drive 5 to grip the boring rod 6, and the drilling process switches to the rotary drive 5.

[0032] In the above structure, the percussion drill head 4 and the rotary drive 5 are mounted side by side. The transmission gear mechanism 38 transmits the torque of the drive motor 10 of the percussion drill head 4 to the rotary drive 5, which rotates the spindle 21 of the rotary drive 5. Therefore, the rotary drive 5 does not need a separate drive source such as an oil motor to rotate the spindle 21. This allows the drive motor 10 of the percussion drill head 4 to be used efficiently. As a result, there is no need to drive the percussion drill head 4 and the rotary drive 5 separately, which allows for a compact and lightweight structure with fewer parts.

[0033] Conventionally, when performing ground improvement work using a percussion drill head, it is necessary to retrieve and splice each boring rod 6 one by one. However, by using a through-type rotary drive 5 to connect multiple boring rods 6 and then transferring them to the percussion drill head 4, the amount of work required to retrieve and splice the boring rods 6 is reduced, enabling more efficient ground improvement work. Furthermore, when drilling with the rotary drive 5 encounters hard ground and drilling becomes difficult, the boring rod 6 can be gripped by the percussion drill head 4, allowing drilling to continue without changing the ground improvement machine, thereby improving drilling efficiency. Furthermore, in ground improvement work using cement injection, the rotary drive 5 is a through-type, allowing for continuous lifting of the boring rod 6, thereby reducing time loss and cement loss during cement injection work. [Explanation of symbols]

[0034] 1 Double Drill Head 2 cases 2a Mounting bracket 4 percussion drill heads 5 Rotary Drive 6 Boring Rods 6a Outer rod 6b Inner Rod 7 Spindle Gear 8 Hammer Sub 9 pins 10 Drive motor 11 Motor pinion 12 bearings 13 Elastic members 14 Counterpinion 15 Counter gear 16 Hammer Spool 20 Through holes 21 spindles 22 bearings 23 Opening 24 Cover Plate 25 End Plates 27 Chuck component 28 Chuck Pieces 29 Chuck spring 30 slide rings 31 Slide Plate 32 Hydraulic Chuck Cylinder 33 Tapered surface 34 Cross roller bearings 35 Spindle Gear 36 keys 38 Transmission Gear Mechanism 40 Ground improvement machine 41 Base Machine 42 Crawler 43 Power Unit 44 guide cells 45 Inclined Cylinder 46 chain 47 Feeding motor 48 Lock Clamps 49 Rod Breaker 50 Slide Table 51 Shift Table 52 Shift mechanism 60 Water inlet 61 Drain 63 Cleaning Swivel 64 Master Coupling 65 Extension Rod

Claims

1. A percussion drill head (4) comprising a hammer sub (8) that transmits impact force and rotational force to a boring rod (6), a drive motor (10) that rotates the hammer sub (8), and an elastic member (13) provided around the hammer sub (8) to mitigate the impact force of the hammer sub (8), A through-type rotary drive (5) is assembled to the percussion drill head (4) in a side-by-side manner, comprising a rotatable spindle (21) through which a boring rod (6) passes, a chuck piece (28) for gripping and releasing the boring rod (6), and a hydraulic chuck cylinder (32) for gripping the chuck piece (28), The percussion drill head (4) is equipped with a transmission gear mechanism (38) that transmits the torque of the drive motor (10) to the rotary drive (5), The transmission gear mechanism (38) comprises a motor pinion (11) provided on the shaft of the drive motor (10), a first counter gear (15) meshing with the motor pinion (11), a first spindle gear (7) meshing with the first counter gear (15) and rotating the hammer sub (8), a second counter gear (15a) meshing with the first spindle gear (7), and a second spindle gear (35) meshing with the second counter gear (15a) and rotating the spindle (21). A double drill head characterized in that, powered by the drive motor (10), the percussion drill head (4) strikes and rotates the boring rod (6) via the first counter gear (15), and the rotary drive (5) grips and rotates the boring rod (6) via the second counter gear (15a).

2. The double drill head according to claim 1, characterized in that the percussion drill head and the through-type rotary drive are attached to the ground improvement machine in a manner that allows for switching of the drilling position.

3. The ground improvement machine comprises a slide table that is movable in the longitudinal direction relative to a guide cell, and a shift table that is movable laterally on the slide table, and the percussion drill head and the through-type rotary drive are characterized in that the drilling position is switched by the lateral movement of the shift table, as described in claim 2.

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