JP2013002039A - Air hammer device for drilling - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air hammer for drilling capable of injecting mortar or cement milk into a vertical hole subsequently to drilling of the vertical hole and reducing equipment cost and the number of processes.SOLUTION: A plurality of air hammers 3 operated by supplied pressure air are incorporated into a body case 2. Each of the air hammers 3 is so configured that, when the pressure air is supplied from an upper part of the body case 2 to a cylinder 7, a piston 9 of the cylinder 7 moves upward and downward by the action of a rigid valve 10 and a check valve 11, and the piston 9 strikes a bit 6 in a fixed cycle. A fluid passage 12 for mortar, cement milk, and the like is provided in the body case 2 so as to vertically penetrate the body case 2.

Description

  In the field of civil engineering and construction, the present invention mainly relates to an air hammer device for drilling holes for drilling vertical holes in hard ground, and more specifically, mortar, cement milk or the like is injected into the ground holes. The present invention relates to an air hammer device for drilling which can make the drilling difficult to collapse.

  In civil engineering and architectural foundation work, in order to increase the support strength of the ground, a cast-in-place concrete pile is constructed by drilling a vertical hole in the ground, or a stress bearing material such as a pile is inserted into the vertical hole. ing.

  Conventionally, a drilling air hammer device that drills a vertical hole in a hard ground incorporates a plurality of air hammers in the body case, and the air hammer is positioned at the upper part of the vertical cylinder and at the lower part thereof. When pressure air is supplied to the cylinder from the air tank provided at the top of the body case, the piston of the cylinder moves up and down by the action of the valve mechanism, and the striking action of this piston is transmitted to the bit and the ground It has a structure for excavation (see, for example, Patent Document 1).

  By the way, under conditions where there is a soft part in the ground, or there is a boulder layer or gravel layer, there is a situation where the peripheral wall of the drilling hole collapses after extraction of the drilling air hammer device, and the quality of cast-in-place piles is reduced. In some cases, there is a problem that the stress is reduced or the stress bearing member cannot be inserted to a predetermined depth.

  For this reason, conventionally, mortar, cement milk, or the like is injected into the drilling hole from which the air hammer device for drilling is extracted to prevent the peripheral wall of the drilling hole from collapsing.

JP 2011-69150 A

  As described above, a method for injecting mortar, cement milk, etc. into a vertical hole after drilling a vertical hole with the air hammer device for drilling and pulling out the air hammer device for drilling from the vertical hole is for drilling. An injection device for mortar, cement milk, etc. must be prepared separately for the air hammer device, and mortar, cement milk, etc. are separately injected, which increases the number of construction steps, construction costs and equipment. There is a problem that the cost is high.

  Accordingly, an object of the present invention is to provide an air hammer device for drilling that can inject mortar, cement milk, etc. into the vertical hole following the drilling of the vertical hole, and can reduce the equipment cost and the number of processes. is there.

In order to solve the above-described problems, the present invention incorporates a plurality of air hammers for excavating the ground by transmitting a striking action of a piston operated by pressure air to a bit in the main body case. Or cement milk or the like so as to penetrate vertically.
The fluid passage has an opening at its lower end at the lower end of the main body case, and an upper end protruding upward from the upper surface of the main body case to serve as a connecting portion for the fluid supply pipe, and the fluid passage is located between adjacent air hammers. A plurality of main body cases can be provided.

  Here, the main body case has a circular outer peripheral surface and is formed long in the vertical direction, and air hammers are incorporated at the inner central position and at a plurality of surrounding locations.

  The air hammer is composed of a bit provided in the lower part of the main body case so as to prevent it from falling out, and a cylinder disposed immediately above the bit. The cylinder accommodates a piston in the cylinder cylinder so that the piston can move up and down. When a rigid valve and a check valve constituting the valve mechanism are installed in the part, and pressure air is supplied to the cylinder from the air tank provided at the top of the main body case, the piston of the cylinder moves up and down by the action of the rigid valve and the check valve. The striking action is transmitted to the bit to excavate the ground.

  In addition, fluid passages such as mortar and cement milk are formed in vertical holes that penetrate the body case along the vertical axis direction, and the portion of the air tank located at the top penetrates vertically by making it a pipe structure. A grout material such as mortar and cement milk can be injected into the perforated vertical hole by the fluid passage.

  According to this invention, in the air hammer device for drilling provided with a plurality of air hammers for excavating the ground by transmitting the striking action of the piston operated by pressure air to the bit, a fluid such as mortar or cement milk is provided in the main body case. Since it is provided so as to penetrate the passage up and down, when a vertical hole is drilled in the ground by hitting the bit with an air hammer, mortar, cement milk, etc. is injected into the vertical hole during the extraction process of the air hammer device for drilling Since the process of preventing the peripheral wall of the vertical hole from collapsing can be performed simultaneously with the extraction of the air hammer device for drilling, it is not necessary to prepare a separate injection device, and the labor required for changing the equipment can be saved. Equipment costs and the number of processes can be reduced.

The front view which notched the principal part of the air hammer apparatus for hole drilling which concerns on this invention An enlarged bottom view showing the arrangement of the bits in the air hammer of the air hammer device for drilling The front view which shows the use condition of the air hammer apparatus for hole drilling which concerns on this invention

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  As shown in the figure, the air hammer device 1 for drilling is composed of a main body case 2 whose outer periphery is called a wear sleeve having a circular shape and is vertically long, a plurality of air hammers 3 incorporated in the main body case 2, and the main body case 2. A cylindrical air inlet 5 is provided at the center of the upper surface of the air tank 4 so as to be connected to the air supply source via an air supply pipe. When pressure air is supplied to the air tank 4, the air hammer 3 transmits a striking action of a piston operated by the pressure air to the bit to excavate the ground.

  The air hammer 3 is composed of a bit 6 provided in the lower part in the vertical hole of the main body case 2 so as to be prevented from coming off, and a cylinder 7 disposed immediately above the bit 6. The cylinder 7 moves the piston 9 up and down inside the cylinder cylinder 8. When a rigid valve 10 and a check valve 11 constituting a valve mechanism are provided at the upper end of the cylinder cylinder 8 and pressure air is supplied to the cylinder 7 from an air tank 4 provided at the upper part of the main body case 2, The piston 9 of the cylinder 7 moves up and down by the action of the valve 10 and the check valve 11, and the piston 9 has a well-known structure that strikes the bit 3 at a constant cycle.

  In the case shown in the drawing, the number and arrangement of the air hammers 3 are arranged at equal intervals in the circumferential direction at the center of the main body case 2 and its three surrounding areas as shown in FIG. The bottom shape is a square shape, one side of the periphery protrudes slightly outside the outer diameter of the main body case 2, and the central bit 6 shows a shape in which the bottom shape of the tip is substantially triangular.

  The main body case 2 is provided with a fluid passage 12 such as a grout material such as mortar or cement milk so as to penetrate vertically, and the fluid passage 12 passes through the inside of the main body case 2 along the vertical axis direction. The portion of the air tank 4 that is formed in the hole and is located at the top penetrates up and down so as to be airtight by having a pipe structure, and the portion that protrudes from the upper surface of the air tank 4 by a predetermined length is made of mortar, cement milk, etc. The inlet 13 has a cylindrical shape for connection to a grout material supply source via a supply pipe.

  In the case of illustration, as shown in FIG. 2, a total of three fluid passages 12 are provided at positions between the respective bits 6 arranged around the main body case 2. Grout material such as cement milk can be injected.

  In addition, the air hammer device 1 for drilling can be configured not to be equipped with the air tank 4 by directly connecting the supply source of the pressure air to each check valve 11, and by omitting the air tank 4, Processing is simplified.

  The air hammer device 1 for drilling according to the present invention has the above-described configuration, and uses a swivel joint 17 on an earth auger 16 suspended from a beam 15 of a self-propelled work machine 14 as shown in FIG. A cylindrical rod 18 is connected, and the drilling air hammer device 1 is attached to the lower end of the rod 18 in an extended arrangement of the coaxial core, and the whole is held vertically to bring the tip of the bit 6 into contact with the ground.

  In the air hammer device 1 for hole drilling, a supply source such as a grout material such as mortar or cement milk is connected to each fluid passage 12 via a swivel joint 17 by a supply pipe 19. 5 and an air supply source are connected using an air supply pipe 20, and in this state, when pressurized air is supplied into the air tank 4, each air hammer 3 is actuated by the rigid valve 10 and the check valve 11, and the piston 9 of the cylinder 7. The piston 9 strikes the bit 6 at a constant cycle, and the bit 6 digs through the ground by the impact of the impact applied to the bit 6.

  As described above, the rotation of the bit 6 and the rotation of the earth auger 16 is applied to dig a vertical hole into the ground. When the vertical hole reaches a predetermined depth, supply of pressure air and the earth auger 16 Stop driving and stop digging.

  As described above, in the step of extracting the hole air hammer device 1 after excavation of the vertical hole reaching a predetermined depth, the hole air hammer device 1 is pulled up and extracted, and at the same time, each fluid passage 12 from the supply source. A grouting material such as mortar and cement milk is supplied to the fluid passage 12 and a grouting material such as mortar and cement milk is injected into the vertical hole from the portion opened at the lower end of the body case 2 of each fluid passage 12. The internal pressure is maintained to prevent the peripheral surface from collapsing.

  Thus, when the grout material such as mortar or cement milk is injected into the vertical hole simultaneously with the lifting of the air hole device 1 for drilling, the grout material such as mortar or cement milk is pulled out. Injection can be performed at the same time, leading to a reduction in the number of processes, and the occurrence of collapse of the inner peripheral surface of the vertical hole can be prevented even under conditions where the excavated ground has a soft part or there is a boulder layer or gravel layer. After the drilling of the air hammer device 1 for drilling, it is possible to construct a cast-in-place concrete pile using a vertical hole or insert a stress bearing material such as a pile into the vertical hole without any trouble.

1 Air Hammer Device 2 for Drilling Main Body Case 3 Air Hammer 4 Air Tank 5 Air Inlet 6 Bit 7 Cylinder 8 Cylinder Tube 9 Piston 10 Rigid Valve 11 Check Valve 12 Fluid Passage 13 Inlet

Claims (2)

  In the main body case, multiple air hammers that excavate the ground by transmitting the impact of the piston operated by pressure air to the bit are built in, and provided in this main body case so that fluid passages such as mortar and cement milk penetrate vertically Air hammer device for drilling holes.   The fluid passage has an opening at its lower end at the lower end of the main body case, and an upper end protruding upward from the upper surface of the main body case to serve as a connecting portion for the fluid supply pipe, and the fluid passage is located between adjacent air hammers. The air hammer device for hole drilling according to claim 1, wherein a plurality of holes are provided for the main body case.

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