JP2008157014A - Earth auger head and excavating construction method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a further efficient earth auger head and an excavating construction method using this auger head, superior in economic efficiency, in the earth auger head incorporating a hammer excavation mechanism (a down-the-hole hammer) for eliminating an inconvenient part of rotary excavation by an auger. <P>SOLUTION: This earth auger head has a rotary excavation mechanism part 1 arranging a spiral blade 12 for earth removal on a peripheral surface of a rotary cylinder part 11 and arranging an excavation bit 13 having the outer peripheral side projecting downward more than the central side on the spiral blade lower end, and a pneumatic impact excavation mechanism part 2 installed in the rotary cylinder part and arranged so that a hammer 23 is stored in an upper position than the excavation bit lower tip. The rotary excavation mechanism part and the impact excavation mechanism part are respectively and independently controlled for driving. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an earth auger head and an excavation method using the auger head.

  A general earth auger head is provided with a spiral blade (screw) for discharging excavated soil at the tip of a rotating shaft, and a bit for ground excavation is provided at the lower end, and drilling is performed by rotating the excavating bit. (Rotary drilling). Drilling excavation (rotary excavation) with the earth auger head described above will cause the ground fracture by the excavation bit to stop when it hits a hard rock during excavation. Had gone.

  Further, as a means for responding to hard rock excavation, there is known an excavation means (blow excavation) in which a pneumatic hammering drill (down-the-hole hammer or the like) applies a strong blow to the rock and crushes and drills the rock (Patent Document). 1). The hitting excavation is effective for hard rock, but the excavation efficiency is poor in general excavation for ground.

  Accordingly, it has been proposed to incorporate a pneumatic blow drill (such as a down-the-hole hammer) into the earth auger head so as to incorporate the advantages of rotary drilling and blow drilling.

  For example, in Patent Documents 2 (Registered Utility Model 3004848), 3 (JP 9-177462 A), and 4 (JP 10-159474 A), the rotating shaft of the earth auger head is formed in a cylindrical shape. And the earth auger head which has arrange | positioned the down-the-hole hammer in the said rotation cylinder is disclosed.

  In addition, when a concrete ready-made pile is put into the excavation hole or a reinforced concrete pile is constructed by inserting a reinforcing rod, the excavation hole is filled with a root hardening liquid such as cement milk prior to the construction of the pile.

  Since the rooting liquid needs to be filled while preventing the excavation hole from collapsing, it is necessary to pull out the earth auger. Therefore, in the earth auger head capable of performing both the rotary excavation and the hitting excavation, as shown in Patent Documents 1 and 3, the excavation rod is provided with a high-pressure air supply path and a liquid supply path, and the auger head A liquid spout is formed, and after the excavation is completed, the ground auger is pulled out and the root hardening liquid is sequentially filled from the bottom of the hole.

  Further, in Patent Document 2, a switching valve mechanism that is switched between the excavation rod and the auger head by switching the weight of the auger head and pushing the excavation rod is interposed so that the high-pressure air supply path also serves as the liquid supply path. Yes.

Japanese Patent Publication No. 7-91930. Registered utility model 3004848. JP-A-9-177462. Japanese Patent Laid-Open No. 10-159474.

  By the way, when the installation position of the down-the-hole hammer in the above-mentioned earth auger head is seen, in Patent Document 4, the rotary excavation bit and the down-the-hole hammer part are formed on the same surface. Even if only rotary excavation with an auger head is performed, the head of the down-the-hole hammer becomes excavation resistance. For this reason, effective drilling cannot be performed unless both rotary drilling with a drill bit of the auger head and hammering drilling are performed simultaneously.

  Also, in the earth auger heads of Patent Documents 2 and 3, the down-the-hole hammer portion protrudes downward from the excavation bit position of the auger head, so hammer hammering excavation is basically the main excavation.

  However, in order to eliminate the inconvenience of the rotary excavation of the earth auger, the impact drilling mechanism (down-the-hole hammer) is incorporated. On the ground where general auger excavation is possible, the incorporation of the impact drilling mechanism is reversed. The rate declines.

  Also in the rooting liquid supply structure, the high pressure air supply path and the liquid supply path disclosed in Patent Documents 1 and 3 are connected to the excavation rod and when the excavation rod is added. Sealing connection is necessary, and the connection of two pipes or a double pipe in a member having a corresponding weight is very troublesome.

  Moreover, only the operation of forming the excavation hole is necessary, and the operation of connecting the two pipes and the operation of connecting the double pipes is a wasteful operation in the operation that does not supply the root hardening liquid.

  Further, the structure using a single supply path and a switching valve as in the earth auger disclosed in Patent Document 2 is relatively easy to connect with the above-described excavating rod or the like. When adopting a structure that switches between the downward movement of the head due to the weight of the auger head and the upward movement of the head due to the pushing of the excavating rod, the head is always pushed in during excavation work because the vertical movement of the impacting body is involved ( The movement state toward the excavation rod side) is not necessarily limited. For this reason, the auger head may reach a position away from the excavation rod, and at that time, there is a high possibility that the excavation earth and sand will be bitten, and the switching valve is connected to the liquid ejection side. As a result, the rotary excavation by the excavation bid located above the impacting body cannot be performed.

  As described above, the switching valve structure based on the relative position of the auger head may adopt a complicated structure in which the excavation work itself may not proceed if the auger head position during the excavation work becomes unstable. This makes the device itself expensive.

  Therefore, the present invention proposes an earth auger head that can perform effective blow excavation and can reliably supply root-setting liquid, and a novel excavation method using the auger head.

  The earth auger head according to the present invention (Claim 1) is provided with a spiral blade for earth removal on the peripheral surface of the rotating cylinder portion, and a drill bit whose outer peripheral side protrudes downward from the center side at the lower end of the spiral blade. A rotary excavation mechanism portion provided; and a pneumatic hammering excavation mechanism portion disposed in the rotary cylinder portion and disposed so that the impacting body is accommodated at a position above the lower end of the excavation bit. It is a feature.

  Further, the excavation method according to the present invention (Claim 5) provides a predetermined excavation of an earth auger head provided with the rotary excavation mechanism portion provided with the excavation bit and the impact excavation mechanism portion provided in the rotary cylinder portion. An earth auger is formed by being connected to a rod, and the rotary excavation mechanism and the impact excavation mechanism are independently driven and controlled when drilling and excavating with the earth auger.

  Thus, the earth auger head is attached to the tip of the excavation rod in the same manner as in the conventional excavation method to form an earth auger, and the earth auger is suspended by a predetermined heavy machine together with a rotary drive mechanism, Drilling and excavation is performed by supplying driving air using a pipe provided in the pipe. Ordinary drilling and excavation for the ground is performed by rotary excavation using a drilling bit. When it hits a hard bedrock, it will also perform impact drilling with the impacting body, increasing overall drilling efficiency.

  Further, the earth auger head according to the present invention (Claim 3) is the above-mentioned earth auger head, in which the excavation rod connecting portion is provided at the upper portion of the rotary cylinder portion of the rotary excavation mechanism portion, and the impact excavation is built from the connecting portion. A high-pressure air supply path that communicates with the high-pressure air receiving section of the mechanism section is formed, a switching valve that is operated by an external operation is interposed in the middle of the high-pressure air supply path, and rotation that is connected to the high-pressure air supply path by the switching valve A liquid discharge path that opens to the outer periphery of the cylindrical portion is formed.

  In the excavation method using the earth auger head according to the present invention (Claim 6), after excavating the excavation hole, the excavation hole is pulled out, and the switching valve is operated to connect the high-pressure air passage and the liquid discharge passage. Connect the earth auger down to the bottom of the drilling hole, supply cemented milk or other rooting liquid to the high-pressure air supply path, and discharge the rooting liquid into the drilling hole while pulling out the earth auger. It is a feature.

  Therefore, at the time of excavation work of the excavation hole, there is no trouble when the switching valve is fixed, and once it is pulled up (when the rooting liquid injection work is not required, it ends with this pulling work), and the excavation rod is connected. In this state, switch the auger head switching valve, set up the earth auger in the excavation hole again, supply rooting liquid such as cement milk from the ground to the high-pressure air supply passage, and pull out the earth auger while rooting in the excavation hole. By discharging the hardening liquid, the root hardening liquid is filled with the excavation hole held.

  The present invention is configured as described above, and by independently performing rotary excavation with a excavation bit, it is possible to efficiently perform excavation excavation on a normal ground, and when hitting a hard rock, hitting excavation with an impactor Therefore, rock drilling with poor drilling efficiency using the drill bit could be performed efficiently.

  Also, since the auger head is provided with an external operation switching valve for the liquid discharge path and the high-pressure air supply path, the work to pull out the earth auger once increases, but compared to the conventional earth auger with a separate liquid supply path Thus, the excavation rod is inexpensive, the excavation rod is easily connected, and each operation can be performed reliably.

  Next, an embodiment of the present invention will be described. FIGS. 1 to 3 show a first embodiment, and this earth auger head includes a rotary excavation mechanism unit 1 and an impact excavation mechanism unit 2.

  The rotary excavation mechanism unit 1 basically has the same configuration as that of the conventional earth auger head. The rotary excavation mechanism unit 1 is provided with a spiral blade 12 for earth removal on the peripheral surface of the rotary tube unit 11, and the outer peripheral side is centered on the lower end of the spiral blade 12. The excavation bit 13 projecting downward from the side is provided. In particular, the excavation bit 13 has a structure in which the outer peripheral side projects downward from the center side.

  Further, a connecting shaft portion 14 for connection with the excavation rod A is provided at the upper end of the rotating cylinder portion 11, and a supply path for high-pressure air serving as a drive source for an impact drilling mechanism portion 2 described later is provided in the rotating cylinder portion 11 and the connecting shaft portion 14. 15 is provided.

  The blow excavation mechanism 2 is a pneumatic drive excavation mechanism called a so-called down-the-hole hammer. A high-pressure air receiving unit 21 is provided at the top so that the high-pressure air receiving unit 21 is connected to the high-pressure air supply path 15. The main body portion 22 is incorporated in the rotary cylinder portion 11. When high-pressure air is supplied, the impacting body 23 standing up the excavation bid 13 at the tip projects at a high speed, and the impacting body 23 collides with the excavation surface. The valve is switched by impact (reaction), and high pressure air is injected from the opening of the impacting body 23 to discharge excavated rock mass powder by air flow, and the impacting body 23 is restored. The excavation proceeds by.

  Further, the storage position of the impacting body 23 is located above the lower end of the excavation bit 13 and the impact projection position is located below the lower end of the excavation bit 13 (about 20 cm in the case of the following external dimensions). In this way, it is incorporated in the rotating cylinder portion 11.

  Further, the outer diameter of the impacting body 23 is set to 1/3 or less of the outer diameter of the excavation bit. For example, when drilling a digging hole of φ500 mm, the outer dimension of the impacting body 23 is set to φ150 mm. In the case of adopting the above dimensions, if all of the φ500mm excavation holes are drilled with down-the-hole hammers, an air consumption of 43 cubic m / min is required to drive, and if φ150mm, the driving air consumption is 9 cubic m / min. Is enough.

  Further, the excavation method of the present invention adopting the earth auger head of the first embodiment is provided with a discharge screw and a trowel plate for hole wall consolidating on the peripheral surface, as well as the conventional excavation method, and is subjected to impact excavation inside. An earth auger is constructed by attaching it to the tip of a predetermined excavation rod provided with a high-pressure air supply path for driving the mechanism unit 2, the excavation rod is connected to a rotary drive mechanism, and suspended by a predetermined heavy machine or the like. Excavation is performed, and operation control of the rotary drive mechanism and operation control of the impact excavation mechanism are performed independently.

  Accordingly, excavation work on the normal ground B is performed by excavating the outer peripheral portion of the excavation hole C with the excavation bit 13 by operating only the rotary drive mechanism, and the center of the face of the excavation hole C is excavated. The portion collapses by digging up by the excavation bit 13 arranged inside, and excavated soil is discharged by the spiral blade 12.

  When the excavated ground reaches the hard rock D, the excavation progress by the excavation bit 13 is delayed, and the face of the excavation hole C is hardly collapsed, and the excavation progress speed is delayed. When the delay is detected, the blow excavation mechanism unit 2 is operated.

  When the striking excavation mechanism 2 operates, the striking body 23 strikes the hard rock D, crushes the rock D, generates a crack E, and proceeds with the excavation.

  As described above, the normal excavation is performed by operating the rotary excavation mechanism unit 1, and the impact excavation mechanism unit 2 is operated only at a location where excavation by the excavation bit 13 is difficult, and the impact excavation mechanism unit 2 has a small diameter. Therefore, the amount of driving air can be reduced, and the incidental equipment cost is reduced accordingly, and the construction method is excellent from the viewpoint of economic efficiency and work efficiency as a whole.

  The earth auger head illustrated in FIGS. 4 and 5 is the second embodiment of the present invention, the basic structure is the same as that of the first embodiment, and particularly in the middle of the high-pressure air supply path 15 in the rotary cylinder portion 11. A switching valve 16 is interposed, a liquid discharge path 17 is provided on the outer periphery of the rotating cylinder connected to the high pressure air supply path 15 by the switching valve 16, and a check valve 18 is provided at the opening end of the liquid discharge path 17. It is provided.

  In particular, the switching valve 16 is operated manually or mechanically, and is switched by an external operation.

  The excavation method of the present invention that employs the earth auger head of the first embodiment of the second embodiment includes a drilling excavation work and a root filling liquid filling work.

  The excavation work is performed in the same manner as the excavation excavation of the first embodiment, with the valve body of the switching valve 16 placed at a position where high-pressure air is supplied to the impact excavation mechanism 2 (FIG. 5A). In particular, since the switching valve 16 is switched only by an external operation, the switching valve 16 is not inadvertently operated during excavation work, and an accurate drilling excavation work is performed.

  When the drilling and excavation work is completed, the earth auger (in which the excavation rod A and the auger head are connected) is once extracted from the excavation hole C, and the switching valve 16 is operated on the ground surface to operate the high-pressure air supply path 15 and the liquid discharge path 17. , Put it in the drilling hole B again, and lower the earth auger to the bottom of the hole.

  In this state, the ground auger is sequentially pulled out while supplying a root hardening liquid such as cement milk from the ground surface to the high-pressure air supply path 15, and the root hardening liquid is filled with the excavation hole C held.

  Therefore, the drilling rod and earth auger head can use a drilling rod with versatility compared to the conventional earth auger with two configurations of the high-pressure air passage and the liquid supply passage. In view of the complexity of the operation) and the inexpensiveness of the members (auger head and excavation rod), even if there is an increase in the operation of pulling out and reinserting the earth auger, it is sufficiently excellent overall.

  Compared to the conventional earth auger head equipped with an automatic switching valve based on the weight of the earth auger head, the earth auger is pulled out and reinserted in consideration of the malfunction of the switching valve at the face where dust and pebbles are rising. Even if there is an increase in the work, the workability is sufficiently excellent overall.

1 is an overall view of a first embodiment of the present invention. Explanatory drawing of the same use state (normal excavation). Explanatory drawing of the state of use (rock excavation). The whole figure of the second embodiment. Explanatory drawing of the same switching valve.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Rotating excavation mechanism part 11 Rotating cylinder part 12 Spiral blade 13 Excavation bit 14 Connecting shaft part 15 High pressure air supply path 16 Switching valve 17 Liquid discharge path 18 Check valve 2 Blow excavation mechanism part 21 High pressure air receiving part 22 Main body part 23 body

Claims (6)

  A rotary excavation mechanism portion provided with a spiral blade for earth removal on the peripheral surface of the rotary cylinder portion, and provided with a drill bit at the lower end of the spiral blade that protrudes downward from the center side on the outer peripheral side; An earth auger head comprising a pneumatic striking excavation mechanism portion disposed so that the striking body is accommodated at a position higher than a lower end of the excavation bit.   The earth auger head according to claim 1, wherein the outer diameter of the impacting body in the impact excavation mechanism section is set to 1/3 or less of the outer diameter of the excavation bit.   A high pressure air supply path is provided which is provided with a drill rod connecting part at an upper part of a rotary cylinder part of the rotary excavation mechanism part, and which communicates with a high pressure air receiving part of an impact drilling mechanism part built in from the connection part. The earth auger according to claim 1 or 2, wherein a switching valve that is operated by an external operation is provided in the middle, and a liquid discharge path that is open to the outer periphery of the rotating cylinder portion connected to the high-pressure air supply path is formed by the switching valve. head.   The earth auger head according to claim 3, wherein the switching valve has a manual switching structure.   A rotary excavation mechanism portion provided with a spiral blade for earth removal on the peripheral surface of the rotary cylinder portion, and provided with a drill bit at the lower end of the spiral blade that protrudes downward from the center side on the outer peripheral side; An earth auger head having a pneumatic batting excavation mechanism portion disposed so that the hitting body is stored at a position above the lower tip of the excavation bit and an appropriate excavation rod to form an earth auger The excavation method is characterized in that when drilling and excavating with the earth auger, the rotary excavation mechanism part and the rear part of the impact excavator are independently driven and controlled.   A rotary excavation mechanism portion provided with a spiral blade for earth removal on the peripheral surface of the rotary cylinder portion, and provided with a drill bit at the lower end of the spiral blade that protrudes downward from the center side on the outer peripheral side; A pneumatic striking excavation mechanism portion disposed so that the striking body is accommodated at a position above the lower tip of the excavation bit, and a drill rod connecting portion is provided above the rotary cylinder portion of the rotary excavation mechanism portion. A high-pressure air supply passage that communicates with the high-pressure air receiving portion of the impact drilling mechanism portion that is internally provided from the connection portion, and a manual switching valve is interposed in the middle of the high-pressure air supply passage, and the high-pressure air is provided by the switching valve. An earth auger head that forms a liquid discharge path that opens to the outer periphery of the rotating cylinder connected to the supply path is connected to a predetermined excavation rod to form an earth auger, which is rotated when drilling with the earth auger. Excavator After the drilling hole of a predetermined depth is formed by independently driving and controlling the head and the impact drilling mechanism, the earth auger is pulled out from the drilling hole, and the switching valve is operated to connect the high pressure air passage and the liquid discharge passage. The earth auger is lowered to the bottom of the excavation hole again, the rooting liquid such as cement milk is supplied to the high pressure air supply passage, and the rooting liquid is discharged into the excavation hole while pulling out the earth auger. Excavation method.

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