JP7475239B2 - Fluid supply device and method for embedding tubular body - Google Patents

Description

The present invention relates to a fluid supply device and a method for embedding a tubular body.

When burying a tubular body (pile material) such as a steel pipe in the ground, the traditional method is to bury the tubular body while excavating the ground inside the body.

For example, Patent Document 1 discloses a method for rotary pressing of a tubular body, in which a tubular body with a drilling blade at its lower end is rotated and pressed into the ground. The rotary pressing method described in Patent Document 1 involves inserting a down-the-hole hammer connected to a fluid supply pipe made of multiple pipes into the inside of the tubular body. This fluid supply pipe is configured to be capable of supplying a driving fluid for driving the down-the-hole hammer and a drilling debris discharge auxiliary fluid, and by using both rotary pressing of the tubular body and drilling of the ground with the down-the-hole hammer, the drilling debris generated by the drilling is transported upward through the inside of the tubular body and discharged to the outside. In Patent Document 1, it is necessary to insert a pin such as a bolt to prevent the tubular body from loosening when rotary pressing the tubular body, and a pin hole (tap hole) is formed in the tubular body.

JP 2019-183626 A

Here, a down-the-hole hammer such as that disclosed in Patent Document 1 generally has a driving attachment and a swivel integrated into one body. The driving attachment is a tubular body that is held by the press-in machine and has a fluid supply pipe disposed inside that supplies water as a driving fluid and air as an auxiliary fluid for discharging excavated debris. The swivel is disposed on the top of the driving attachment and is connected to supply pipes for water and air that are supplied to the fluid supply pipe.

However, with this configuration, the overall length of the down-the-hole hammer becomes long (for example, the overall length of the swivel and driving attachment is 4 m or more), and the down-the-hole hammer cannot be used at sites with low overhead restrictions (such as under bridge girders).

The present invention aims to provide a fluid supply device and a method for embedding a tubular body that allows the use of a down-the-hole hammer even in locations with low overhead restrictions.

The fluid supply device of the present invention supplies fluid to drive a bit section that is inserted into a tubular body that is pressed into the ground to perform excavation, and includes a fixed section to which a rod section having the bit section at its tip can be connected, and a connecting section that is attached to the fixed section via a flange provided on the outer periphery of the fixed section and is fitted into the tubular body.

According to this configuration, the fixing part is a member that fixes the down-the-hole hammer, which uses a fluid (water as an example) to drive the bit part to drill, and the connecting part is attached via a flange provided on the outer periphery of this fixing part. Then, the tubular body is fitted into the connecting part, making it possible to press the tubular body in while using the down-the-hole hammer.

Conventionally, the fixed part and the tubular body (also called the down-the-hole pipe section) connected to the fixed part were one piece, so the overall length was long (4m or more), and construction using a down-the-hole hammer was only possible at sites with sufficiently high overhead restrictions.

However, in this configuration, by attaching the connecting part to the fixed part, the tubular body (down-hole pipe tube part) connected to the fixed part can be made separate from the fixed part. This allows a short tubular body to be selected as the tubular body connected to the fixed part. Therefore, construction using a down-the-hole hammer can be performed even at sites with low overhead restrictions.

In the fluid supply device of the present invention, a hole is formed in the flange into which a bolt is inserted, and a groove is formed on the upper surface of the connecting portion into which the bolt is fastened.

This configuration allows the connecting part to be attached to the fixed part with a simple structure. In addition, the connecting part and the flange are fixed with bolts, so that the reaction force of the down-the-hole hammer is transmitted to the fixed part via the bolts.

The fluid supply device of the present invention has a protrusion into which the flange is inserted into the connecting portion.

According to this configuration, the protrusions on the flange are inserted into the connecting part, and the torque in the rotational direction is transmitted to the fixed part by fastening the fixed part and the connecting part with a bolt.

In the fluid supply device of the present invention, the fixing part and the connecting part are connected via a spacer between the flange and the connecting part.

This configuration allows the position of the bit portion relative to the tip of the tubular body to be easily and continuously adjusted. In addition, the bolt length can be secured by the thickness of the spacer, improving torque resistance.

The fluid supply device of the present invention has a protrusion on the peripheral surface of the tubular body, and the tubular body is fitted into the connecting portion and rotated in either the left or right direction about the long axis of the tubular body to form a first fitting portion that fits into the protrusion.

This configuration allows the connecting portion and the tubular body to be connected easily and firmly.

In the fluid supply device of the present invention, the protrusion provided on another tubular body is fitted into the tubular body, and the tubular body is rotated in the opposite direction to the above direction to form a second fitting portion that fits into the protrusion.

According to this configuration, the direction in which the tubular bodies are connected to the connecting part is opposite to the direction in which the tubular bodies are connected to each other. The direction in which the tubular bodies are connected to each other is the same as the rotational direction (forward direction, as an example, counterclockwise) when the tubular bodies are gripped and pressed in. As a result, even if the tubular body connected to the tubular body (downward pipe cylinder part) connected to the connecting part is gripped and rotated and pressed in, the connection is maintained without loosening of the engagement by the second fitting part. Therefore, there is no need to form a pin hole for inserting a pin to prevent loosening in the second fitting part.

If the first and second fitting parts were oriented in the same direction, there is a possibility that the fitting by the first fitting part may become loose when the tubular body, which is the downdraft pipe cylinder part, is gripped and rotated in the normal direction.

Therefore, as in this configuration, by making the first fitting portion formed on the connecting portion and the second fitting portion formed on the tubular body face in opposite directions, when the tubular body, which is the downdraft pipe cylinder portion, is gripped and rotated, the protrusion of the tubular body will press the first fitting portion of the connecting portion. This causes the fluid supply device to rotate together with the tubular body. Therefore, the connection is maintained without loosening of the fitting by the first fitting portion, so there is no need to form a pin hole in the first fitting portion for inserting a pin to prevent loosening.

At sites with low overhead restrictions, multiple tubular bodies with short overall lengths according to the height of the restrictions are buried together. For this reason, if a process of inserting an anti-loosening pin into each connected tubular body were required at sites with low overhead restrictions, the amount of work would increase. For this reason, eliminating the need for the process of inserting pins into pin holes at sites with low overhead restrictions would contribute to reducing the amount of work required.

The method for embedding a tubular body of the present invention involves connecting the tubular body to the fluid supply device described above, and embedding the tubular body by rotating and pressing it while supplying fluid to the inside of the tubular body.

According to the present invention, the down-the-hole hammer can be used even at sites where there are overhead restrictions and the restricted height is low, such as under bridge girders.

FIG. 2 is an external side view of the press-fitting machine of the present embodiment. FIG. 2 is a diagram showing the configuration of a downdraft pipe according to the present embodiment. FIG. 2 is a configuration diagram of a fixed attachment according to the present embodiment. FIG. 2 is a diagram showing the configuration of the down-throwing pipe tube portion and the rod portion of the present embodiment. 1A and 1B show the change in the position of the bit portion when the spacer of this embodiment is used, in which (A) shows the bit portion protruding downward from the bottom end of the small-diameter pipe, and (B) shows the bit portion at approximately the same height as the bottom end of the small-diameter pipe. FIG. 4 is a top view of the flange of the present embodiment. FIG. 2 is a top view of the head portion of the embodiment. 10 is a top view showing a connection state between the flange and the head portion with the spacer sandwiched therebetween in this embodiment. FIG. 4 is a cross-sectional view showing a connection state between a flange and a head portion with a spacer sandwiched therebetween in this embodiment. FIG. 1A and 1B are diagrams showing the case where the tubular portion of the down-driving pipe and the small-diameter pipe of this embodiment are grasped and rotated, in which (A) shows the case where the small-diameter pipe to be buried is grasped and rotated, and (B) shows the case where the tubular portion of the down-driving pipe is grasped and rotated. 1A and 1B show overhead restrictions when using the water hammer of this embodiment, where (A) shows construction during installation, (B) shows construction completed, (C) shows construction using a conventional water hammer, and (D) shows construction completed using a conventional water hammer.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Note that the embodiment described below is an example of how the present invention can be implemented, and the present invention is not limited to the specific configuration described below. When implementing the present invention, a specific configuration according to the embodiment may be appropriately adopted.

Figure 1 is an external side view of the pressing machine 10 of this embodiment. In the following embodiment, we will explain how the present invention is applied to the rotary pressing of a small-diameter pipe 3, which is an example of a tubular body, based on the case of constructing a wall structure 1 consisting of a steel pipe pile 2 and a small-diameter pipe 3 in the ground.

In this embodiment, the tubular body buried using the down-the-hole hammer 25 is a small-diameter pipe 3, as described in detail below, but this is just one example, and the tubular body buried using the down-the-hole hammer 25 is not limited to a small-diameter pipe 3. When burying a small-diameter pipe 3, a small-diameter attachment (not shown) or a small-diameter chuck (not shown) may be used in the press-in machine 10 to hold the small-diameter pipe 3. In this embodiment, the small-diameter pipe 3 is held by the press-in machine 10 using a small-diameter chuck, as one example, and buried.

The press-fitting machine 10 includes a saddle 11, a clamp device 12 provided under the saddle 11, a slide base 13 provided so as to be movable back and forth on the saddle 11, a swivel base 14 provided so as to be rotatable on the slide base 13, a chuck device 16 supported on the front end of the swivel base 14 via a lifting cylinder device 15, and a crane 20 supported on the swivel base 14.

The pressing machine 10 grasps the upper end of the existing steel pipe pile 2 pressed into the ground, and while taking the reaction force from the existing steel pipe pile 2, it grasps the new steel pipe pile 2 with a chucking device 16 that can be raised and lowered, thereby pressing the new steel pipe pile 2 into the ground. The clamping device 12 has the function of moving the gripping claws inserted into the interior from the upper end opening of the existing steel pipe pile 2 in the radial direction of the steel pipe pile 2. The gripping claws are moved radially outward of the existing steel pipe pile 2 and brought into a state of tension inside the steel pipe pile 2, thereby gripping the existing steel pipe pile 2 from the inside. This fixes the pressing machine 10 to the existing steel pipe pile 2.

The chuck device 16 has a chuck portion 17 that grips the steel pipe pile 2, and the chuck portion 17 has an opening 17a for inserting the steel pipe pile 2 and a plurality of pile gripping claws 17b that can move in the radial direction of the steel pipe pile 2 inserted into the opening 17a. After the steel pipe pile 2 is inserted into the opening 17a, the chuck portion 17 grips the steel pipe pile 2 by moving the pile gripping claws 17b radially inward of the steel pipe pile 2. The chuck device 16 is also configured to rotate the chuck portion 17. That is, the pressing machine 10 of this embodiment is a rotary pile pressing machine, and the steel pipe pile 2 (steel pipe pile with a tip bit) is pressed into the ground while rotating by a combination of the rotation of the chuck portion 17 of the chuck device 16, switching between the gripping state and the release state by the pile gripping claws 17b, and the lifting and lowering movement by the lifting and lowering cylinder device 15. The above configuration is the same as that of the GyroPiler (registered trademark) used in the so-called GyroPress method (registered trademark).

The press-in machine 10 of this embodiment presses in the small-diameter pipe 3 using a down-the-hole hammer 25. The down-the-hole hammer 25 is inserted into the inside of the small-diameter pipe 3, which is a tubular body. The small-diameter pipe 3 is made of a cylindrical steel pipe, and as shown in FIG. 5, the lower end surface of the small-diameter pipe 3 is provided with a digging blade 3a that digs into the ground by rotating the small-diameter pipe 3.

The down-the-hole hammer 25 in this embodiment is, as an example, a so-called water hammer that uses water as the driving fluid, and for example, a Wassara hammer manufactured by Wassara (Wassara is a registered trademark) is used. A bit portion 55 for excavating the ground is detachably attached to the lower end of the down-the-hole hammer 25. In the following explanation, the down-the-hole hammer 25 will be explained as a water hammer 25.

In the following explanation, "up" or "down" in the explanation of the water hammer 25 means "up" or "down" when the water hammer 25 is in use, i.e., when the water hammer 25 is inserted into the small-diameter pipe 3 and the small-diameter pipe 3 is being rotated and pressed into the ground by the pressing machine 10.

The driving fluid supply device of the water hammer 25 of this embodiment will be described below with reference to Figures 2 to 5. Figure 2 is a configuration diagram of the driving pipe 30 of this embodiment. Figure 3 is a configuration diagram of the fixed attachment 31 of this embodiment. Figure 4 is a configuration diagram showing the driving pipe tubular portion 32 and rod portion 33 of this embodiment. Figure 5 is a diagram showing the bit portion 26 provided on the water hammer 25.

The downdraft pipe 30 in this embodiment has a cylindrical shape through which the fluid supply pipe 42 can be passed, similar to the small diameter pipe 3, and is composed of a fixed attachment 31, a downdraft pipe tubular portion 32, and a rod portion 33.

The fixed attachment 31 is a fixing device that fixes the rod portion 33, which has the bit portion 26 at its tip, and is also a fluid supply device that supplies fluid to the water hammer 25. The fixed attachment 31 includes a swivel 40 and a head portion 41.

The swivel 40 is inserted into the small diameter pipe 3 that is pressed into the ground to supply fluid (water) to drive the bit section 26 that performs the excavation, and is a fixed section to which the rod section 33, at the tip of which the bit section 26 is located, can be connected.

The head portion 41 is attached to the swivel 40 via a flange 43 provided on the outer periphery of the swivel 40, and is a connecting portion that fits into the down-throw pipe tube portion 32. The head portion 41 is shaped like a cylinder that is open at the top and bottom, and the fluid supply pipe 42 of the swivel 40 is inserted through it. A receiving portion 44 is provided on the top of the head portion 41, and the top surface of the down-throw pipe tube portion 32 abuts against the bottom surface of the receiving portion 44, thereby determining the upper position of the down-throw pipe tube portion 32.

The downdraft pipe tube 32 is connected to the fixed attachment 31 by the head 41, and its configuration is the same as that of the small-diameter pipe 3, making it possible to grasp it with the press-in machine 10.

The rod portion 33 is connected to the tip of the fluid supply pipe 42 of the swivel 40. The rod portion 33 can be extended by connecting multiple rod portions 33 together depending on the buried state of the small-diameter pipe 3, and the bit portion 26 is provided at the tip of the multiple connected rod portions 33.

The fluid supply pipe 42 of the swivel 40 is a multiple pipe, and in this embodiment, the fluid supply pipe 42 is configured as a double pipe, and supplies water, which is the driving fluid of the water hammer 25, and air, which is the excavation debris discharge auxiliary fluid. A water supply pipe 44A and an air supply pipe 44B are connected to the upper end of the fluid supply pipe 42. Water, which is the driving fluid of the water hammer 25, is supplied to the fluid supply pipe 42 from the supply pipe 44A, and air, which is the excavation debris discharge auxiliary fluid, is supplied to the fluid supply pipe 42 from the supply pipe 44B.

The excavation debris discharge assist fluid is a fluid for facilitating the discharge of excavation debris (excavated soil, crushed rock, etc.) generated at the lower end of the small-diameter pipe 3 to the ground. In this embodiment, air is used as the excavation debris discharge assist fluid. An outlet (not shown) for blowing out air as the excavation debris discharge assist fluid is provided near the top of the bit portion 26. The air supplied from the fluid supply pipe 42 is blown out from this outlet into the inside of the small-diameter pipe 3.

Here, the conventional downdraft pipe 100 (see Figure 11) had a one-piece structure with the swivel and the downdraft pipe tubular section connected to the swivel, so it had a long overall length (4m or more), and could not be used for construction using a water hammer 25 unless the site had a sufficiently high overhead restriction.

However, in the case of the driving pipe 30 of this embodiment, the head portion 41 is attached to the swivel 40, so that the swivel 40 and the driving pipe tube portion 32 can be separate. This allows a shorter, smaller-diameter pipe 3 to be selected as the driving pipe tube portion 32 connected to the swivel 40. Therefore, the driving pipe 30 of this embodiment makes it possible to carry out construction using the water hammer 25 even at sites where there are overhead restrictions and the restricted height is low, such as under bridge girders. In other words, the water hammer 25 equipped with the driving pipe 30 of this embodiment can be used as a water hammer for low overhead.

Next, the connection between the swivel 40 and the head portion 41 of this embodiment will be described with reference to Figs. 6 to 9. Fig. 6 is a top view of the flange 43, and Fig. 7 is a top view of the head portion 41 of this embodiment. Fig. 8 is a top view showing the connection between the flange 43 and the head portion 41 with the spacer 50 of this embodiment sandwiched therebetween. Fig. 9 is a cross-sectional view showing the connection between the flange 43 and the head portion 41 with the spacer 50 of this embodiment sandwiched therebetween.

As described above, the swivel 40 and the head portion 41 are connected via the flange 43 provided on the outer periphery of the swivel 40. In this embodiment, the swivel 40 and the head portion 41 are connected by fastening with a bolt 51, for example.

For this reason, the flange 43 of this embodiment is formed with a hole (hereinafter referred to as "bolt hole") 52A into which the bolt 51 is inserted, and the upper surface of the head portion 41 is formed with a groove (hereinafter referred to as "bolt groove") 52B into which the bolt 51 is fastened. This allows the head portion 41 to be attached to the swivel 40 with a simple configuration. In addition, by fixing the head portion 41 and the flange 43 with the bolt 51, the reaction force of the water hammer 25 is transmitted to the swivel 40 via the bolt 51. Note that in this embodiment, the flange 43 and the head portion 41 are formed with the bolt holes 52A and the bolt grooves 52B at equal positions in the circumferential direction. As a result, the force is transmitted evenly in the circumferential direction of the swivel 40 by fastening with the bolt 51.

Furthermore, the flange 43 of this embodiment has a protrusion (hereinafter referred to as "pin") 53A that is inserted into the head portion 41. Therefore, a pin hole 54A is formed in the flange 43 into which the pin 53A is inserted. A pin hole 54B is formed in the upper surface of the head portion 41. With this configuration, the swivel 40 and the head portion 41 are fastened by the bolt 51, and the pin 53A of the flange 43 is inserted into the pin hole 54B of the head portion 41, so that torque in the rotational direction is transmitted to the swivel 40.

In addition, in this embodiment, the swivel 40 and the head portion 41 can be connected via a spacer 50 between the flange 43 and the head portion 41.

As shown in FIG. 5, the spacer 50 is, for example, a plate-like or block-like member for changing the height of the bit portion 55 relative to the lower end of the small-diameter pipe 3. FIG. 5(A) shows the state in which the bit portion 26 protrudes downward from the lower end of the small-diameter pipe 3, and FIG. 5(B) shows the state in which the bit portion 26 is set to the same height as the lower end of the small-diameter pipe 3. That is, by adjusting the number of spacers 50 sandwiched between the flange 43 and the head portion 41 and the thickness of each spacer 50, the bit portion 55 at the lower end of the water hammer 25 can be protruded downward from the drilling blade 3a at the lower end of the small-diameter pipe 3, or the bit portion 55 at the lower end of the down-the-hole hammer 25 can be retracted upward from the drilling blade 3a at the lower end of the small-diameter pipe 3.

In this embodiment, the position of the bit portion 26 can be easily and steplessly adjusted by adjusting the number of spacers 50 and the thickness of each spacer 50. The spacers 50 in this embodiment are formed with bolt holes 52C for inserting the bolts 51. This ensures that the bolt length is equal to the total thickness of the spacers 50, improving torque resistance.

In addition, in the spacer 50 of this embodiment, the flange 43 has a pin 53A, so a pin hole 54C is formed into which the pin 53A is inserted, and the pin 53B is inserted into the pin hole 54C. The pin 53B of the spacer 50 is inserted into the pin hole 54C of another spacer 50 overlapping below, or into the pin hole 54B formed in the upper surface of the head portion 41.

In this embodiment, with the above configuration, the spacer 50 is disposed and temporarily fixed between the flange 43 and the head portion 41 by the pins 53A and 53B, and the flange 43, the head portion 41, and the spacer 50 are firmly connected by fastening with the bolt 51. More specifically, the pins 53A and 53B are used to temporarily fasten the spacers 50 together and between the flange 43 and the head portion 41, and although they are easy to install, they are weaker in strength than fastening with the bolt 51. On the other hand, the bolt 51 is used to completely fix the above-mentioned components by fastening, and although it takes time to install, it is stronger than the pins 53A and 53B.

In this embodiment, three pairs of bolt holes 52A and bolt grooves 52B are formed, and the flange 43 and head portion 41 are fastened by three bolts 51, but this is one example, and fastening may be performed by four or more or two or less bolts 51. Also, in this embodiment, the flange 43 and head portion 41 are also connected by pins 53A and 53B, but fastening may be performed only by bolts 51, and connection by pins 53A and 53B may not be performed.

Next, we will explain the connection between the head portion 41 and the downdraft pipe tube portion 32 in this embodiment, and the connection between the downdraft pipe tube portion 32 and the small diameter pipe 3.

In this embodiment, the tubular pipe 32 has a protrusion 60 on the circumferential surface (see FIG. 4). The tubular pipe 32 is fitted into the head 41, and the head 41 is rotated in either the left or right direction (hereinafter referred to as the "first rotation direction") around the long axis of the tubular pipe 32 to form a fitting portion 61A that fits into the protrusion 60. In this embodiment, the protrusion 60 is rectangular in shape so as to fit into the L-shaped fitting portion 61A, but other shapes are also possible. For example, the protrusion 60 and the fitting portion 61A may be formed in a comb-like shape, and the teeth of the comb may mesh with each other to fit more firmly.

In addition, the protrusion 60 provided on the down-casting pipe tube portion 32 in this embodiment is provided on the inner peripheral surface of the down-casting pipe tube portion 32, as an example. Therefore, the fitting portion 61A of the head portion 41 is inserted into the inside of the down-casting pipe tube portion 32 and fits with the protrusion 60.

More specifically, the outer diameter of the fitting portion 61A is slightly smaller than the inner diameter of the down-throw pipe tube portion 32, and the fitting portion 61A can be inserted into the inside of the down-throw pipe tube portion 32 from the upper end of the down-throw pipe tube portion 32. The outer peripheral surface of the fitting portion 61A is provided with an L-shaped groove portion 64 having a vertical passage 62 and a horizontal passage 63. When the fitting portion 61A is inserted into the inside of the down-throw pipe tube portion 32 from the upper end, the protrusion 60 attached to the inner surface of the upper end of the down-throw pipe tube portion 32 is passed through the vertical passage 62 of the groove portion 64. Then, when the protrusion 60 reaches the horizontal passage 63 of the groove portion 64, the fixed attachment 31 and the down-throw pipe tube portion 32 are rotated relative to each other. As a result, the protrusion 60 is moved horizontally within the horizontal passage 63 of the groove portion 64, and the protrusion 4 is inserted into the innermost part of the horizontal passage 63. Therefore, the protrusion 4 fits into the lateral passage 63 of the groove 64, connecting the fixed attachment 31 to the upper end of the downdraft pipe tube 32.

In this manner, in this embodiment, the fixed attachment 31 and the downdraft pipe tube portion 32 are simply and firmly connected by fitting the protrusion 60 on the downdraft pipe tube portion 32 with the fitting portion 61A on the head portion 41.

On the other hand, the protrusion 60 provided on the small diameter pipe 3 is fitted into the downdraft pipe tube portion 32, and by rotating it in a second rotation direction that is the opposite direction to the first rotation direction, a fitting portion 61B that fits into the protrusion 60 is formed. That is, the protrusion 60 is formed at one end of the downdraft pipe tube portion 32, and the fitting portion 61B is formed at the other end.

The small-diameter pipe 3 buried by the pressing machine 10 of this embodiment has the same configuration as the driven-down pipe tube section 32. Therefore, the fitting section 61B of the driven-down pipe tube section 32 of this embodiment is inserted inside the small-diameter pipe 3 and fits with the protrusion 60 of the small-diameter pipe 3, thereby connecting the driven-down pipe tube section 32 and the small-diameter pipe 3. Furthermore, small-diameter pipes 3 are also connected to each other by fitting the protrusion 60 with the fitting section 61B.

The fitting portion 61A and the fitting portion 61B have opposite orientations of the horizontal passage 63 relative to the vertical passage 62. In other words, the fitting portion 61A and the fitting portion 61B have opposite fitting directions with the protrusion 60. As a result, the first rotation direction for connecting the down-thrust pipe tube portion 32 to the head portion 41 is opposite to the second rotation direction for connecting the down-thrust pipe tube portion 32 to the small-diameter pipe 3 or to each other small-diameter pipes 3. The second rotation direction in this embodiment is the same as the rotation direction (forward direction, for example counterclockwise) when the small-diameter pipe 3 is gripped and pressed in.

Furthermore, it is sufficient that one or more projections 60 and fittings 61A, 61B are provided in the circumferential direction of the head portion 41, the downdraft pipe tube portion 32, and the small-diameter pipe 3, respectively.

Here, FIG. 10 is a schematic diagram of the case where the downdraft pipe tube portion 32 and the small diameter pipe 3 of this embodiment are gripped and rotated. FIG. 10(A) shows the case where the small diameter pipe 3 to be buried is gripped and rotated, and FIG. 10(B) shows the case where the downdraft pipe tube portion 32 is gripped and rotated.

When the small-diameter pipe 3 is pressed in, the small-diameter pipe 3 is rotated in the normal direction while being gripped (see FIG. 10(A)). This maintains the connection without loosening the fitting by the fitting portion 61B. Therefore, there is no need to form a pin hole in the fitting portion 61B for inserting a loosening prevention pin (also called a reamer bolt).

If the orientation of the fitting portion 61A and the fitting portion 61B were the same, when the down-thrust pipe tube portion 32 was gripped and rotated in the forward direction, the protrusion 60 of the down-thrust pipe tube portion 32 would move in a direction that disengaged it from the fitting portion 61A, which could cause the fitting by the fitting portion 61A to loosen.

Therefore, as in this embodiment, by making the orientation of the fitting portion 61A formed on the head portion 41 the opposite direction to the orientation of the fitting portion 61B, when the down-driving pipe tube portion 32 is gripped and rotated in the first rotation direction, the protrusion 60 of the down-driving pipe tube portion 32 presses the fitting portion 61A of the head portion 41 (arrow A in FIG. 10(B)). This causes the fixed attachment 31 to rotate together with the down-driving pipe tube portion 32. Therefore, simply gripping the down-driving pipe tube portion 32 and rotating it in the first rotation direction maintains the connection without loosening the fitting by the fitting portion 61A, so there is no need to form a pin hole here for inserting a pin to prevent loosening.

At sites with low overhead restrictions, multiple small-diameter pipes 3 with short overall lengths according to the height of the restrictions are buried together. For this reason, if a process of inserting an anti-loosening pin into a pin hole for each small-diameter pipe 3 were required at sites with low overhead restrictions, the amount of work would increase. For this reason, eliminating the need for the process of inserting pins into pin holes at sites with low overhead restrictions would contribute to reducing the amount of work required.

Figure 11 shows the overhead restrictions when using the driving pipe 30 of this embodiment, with Figure 11(A) showing the time of construction and Figure 11(B) showing the time of completion of construction. Meanwhile, Figure 11(C) shows the time of construction using a conventional driving pipe 100, and Figure 11(D) shows the time of completion of construction using a conventional driving pipe 100. As shown in Figure 11, the method of burying the small-diameter pipe 3 of this embodiment is to connect the small-diameter pipe 3 to the driving pipe 30 of this embodiment, which has the driving pipe tubular portion 32 connected to the fixed attachment 31, and while supplying fluid to the inside of the small-diameter pipe 3, the small-diameter pipe 3 is rotated and pressed in by the pressing machine 10 to bury it.

As shown in Figures 11(C) and (D), construction using a conventional drop pipe 100 required an overhead restriction of, for example, 7 m or more. On the other hand, as shown in Figures 11(A) and (B), the drop pipe 30 of this embodiment has a shorter overall length than the conventional drop pipe 100, so construction using the drop pipe 30 is possible even at sites where the overhead restriction is, for example, 5.0 m, which is lower than when the conventional drop pipe 100 is used.

The present invention has been described above using the above embodiment, but the technical scope of the present invention is not limited to the scope described in the above embodiment. Various modifications or improvements can be made to the above embodiment without departing from the gist of the invention, and forms with such modifications or improvements are also included in the technical scope of the present invention.

In the above embodiment, the protrusion 60 is provided on the inner peripheral surface of the down-throw pipe tube 32 and the small-diameter pipe 3, but the present invention is not limited to this, and the protrusion 60 may be provided on the outer peripheral surface of the down-throw pipe tube 32 and the small-diameter pipe 3. In this case, the inner diameter of the fitting portion 61A of the head portion 41 is slightly larger than the outer diameter of the down-throw pipe tube 32, and the fitting portion 61A is fitted from the upper end of the down-throw pipe tube 32 to fit with the protrusion 60. In addition, the inner diameter of the fitting portion 61B provided on the down-throw pipe tube 32 and the small-diameter pipe 3 is also slightly larger than the outer diameter of the down-throw pipe tube 32 and the small-diameter pipe 3.

In the above embodiment, the protrusions 60 are provided in a single row in the circumferential direction of the downdraft pipe tube portion 32 and the small-diameter pipe 3, but the present invention is not limited to this, and multiple rows may be provided in the longitudinal direction of the downdraft pipe tube portion 32 and the small-diameter pipe 3. In this case, multiple rows of lateral passages 63 are formed in the fitting portions 61A and 51B to correspond to the multiple rows of protrusions 60.

In the above embodiment, the projection 60 is engaged with the fittings 61A and 51B to connect the fixed attachment 31 to the tubular down-thrust pipe 32, and to connect the tubular down-thrust pipe 32 to the small-diameter pipe 3. However, the present invention is not limited to this. As long as the fixed attachment 31 and the tubular down-thrust pipe 32 can be detachably connected, and the tubular down-thrust pipe 32 and the small-diameter pipe 3 can be detachably connected, other configurations may be applied, such as connecting each of them with a pin.

In the above embodiment, the bit portion 26 is attached to the tip of the water hammer 25, but the present invention is not limited to this, and the small-diameter pipe 3 may be buried without attaching the bit portion 26 depending on the hardness of the ground. In this case, for example, a hose may be attached to the tip of the fluid supply pipe 42 of the fixed attachment 31, and water may be supplied from this hose to the inside of the small-diameter pipe 3 while it is buried.

In the above embodiment, a water hammer 25 is described in which the driving fluid of the down-the-hole hammer is water, but the present invention is not limited to this, and a down-the-hole hammer in which the driving fluid is compressed air may also be used.

3. Small diameter piping (tubular body)
26 Bit 31 Fixed attachment (fluid supply device)
32 Downward-moving pipe cylinder portion 40 Swivel (fixed portion)
41 Head part (connecting part)
43 Flange 50 Spacer 51 Bolt 52A Bolt hole (hole)
52B Bolt groove (groove)
53A Pin (protrusion)
60: protrusion 61A: fitting portion 61B: fitting portion

Claims (6)

A fluid supply device for supplying a fluid to a down-the-hole hammer having a bit portion that is inserted into a tubular body that is gripped by a press machine and pressed into the ground to perform drilling,
a swivel having a fluid supply pipe for supplying a fluid for driving the bit portion, and to which a rod portion having the bit portion disposed at a tip thereof can be connected;
a connecting portion having a circular tube shape with openings at the top and bottom, through which the fluid supply pipe is inserted, which is attached to the swivel via a flange provided horizontally with respect to an outer periphery of the swivel , and which is fitted to the tubular body;
Equipped with
The swivel and the connecting portion are connected via a spacer between the flange and the connecting portion in order to change the protruding state of the bit portion from the lower end of the down-the-hole hammer,
A fluid supply device in which, when the connecting portion and the tubular body are fitted together, the upper position of the tubular body is determined at the position of the upper surface of the connecting portion, and the connecting portion fits within the inner circumference of the tubular body . The flange has a hole through which a bolt is inserted,
The fluid supply device according to claim 1 , wherein an upper surface of the connecting portion is formed with a bolt groove into which the bolt is fastened. The fluid supply device according to claim 1 or 2, wherein the flange has a protrusion that is inserted into the connecting portion. The tubular body has a protrusion on a circumferential surface thereof,
4. The fluid supply device according to claim 1, wherein the connecting portion is formed with a first fitting portion that fits into the protrusion by fitting the tubular body into the connecting portion and rotating the tubular body in either the left or right direction around the long axis of the tubular body as an axial center, the first fitting portion being formed. The fluid supply device according to claim 4 , wherein the tubular body is rotated in a direction opposite to the direction in which the protrusion is fitted onto the other tubular body, thereby forming a second fitting portion that fits onto the protrusion. A method for embedding a tubular body, comprising : connecting the tubular body to the fluid supply device according to claim 1; and embedding the tubular body by rotating and pressing the tubular body while supplying a fluid into the inside of the tubular body.