steel pipe Hangzhou

Abstract

To improve mounting accuracy without complicating construction work when individually mounting a drilling bit to the tip of a steel pipe pile.SOLUTION: A drill bit that comprises a plate-like main body portion that is joined to an axial end face of a steel pipe pile and includes a portion that protrudes from an end face toward an inner peripheral surface side or an outer peripheral surface side of the steel pipe pile when viewed in the axial direction, and an extension portion formed continuously from a portion of the main body portion protruding toward the inner peripheral surface side or the outer peripheral surface side of the steel pipe pile, extending along the inner peripheral surface or the outer peripheral surface, and directly or indirectly joined to the inner peripheral surface or the outer peripheral surface is provided.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention ,steel relates to pipe piles.

Background Art

[0002] The excavation bit attached to the tip of a steel pipe pile is expected to not only have the conventional effect of excavating the ground, but also control the movement of soil and sand according to the rotation direction of the pile and suppress or promote the blockage of soil inside the pipe. As a method of attaching such an excavation bit to a steel pipe pile, Patent Document 1 describes a configuration in which a cylindrical body is connected and fixed to the tip of a steel pipe pile, and the excavation bit protrudes from the tip surface of the cylindrical body. Patent Document 2 also shows a configuration in which a cutter bit is attached to the tip of a steel pipe pile via a ring. More specifically, Patent Document 2 shows a configuration including a tip member that contacts the ground and a shank member that supports the tip member, and the tip member is inserted and fixed into an insert groove formed in the shank member.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] As described in Patent Documents 1 and 2 above, if a component such as a ring to which a drilling bit is attached is attached to the tip of a steel pipe pile, the drilling bit and its support member can be joined to the ring in advance, making it relatively easy to set the mounting angle of the drilling bit and the length of its protrusion from the steel pipe pile. On the other hand, there are also cases where multiple drilling bits are individually attached to the tip of a steel pipe pile by welding or other means. Such a mounting method is suitable, for example, for attaching drilling bits in on-site construction. However, in this case, it is necessary to attach each drilling bit while checking its mounting angle and protrusion length using an angle gauge or jig, which can make the construction procedure complicated and make it difficult to ensure mounting accuracy.

[0005] Therefore, the present invention makes it possible to improve the accuracy of attachment when individually attaching drilling bits to the tip of a steel pipe pile without complicating the construction process. steel The objective is to provide pipe piles. [Means for solving the problem]

[0006] [1] A drilling bit comprising: a plate-shaped main body portion joined to the axial end face of a steel pipe pile, including a portion that protrudes from the end face towards the inner or outer circumferential surface of the steel pipe pile when viewed in the axial direction; and an extension portion formed continuously with the portion of the main body portion that protrudes towards the inner or outer circumferential surface of the steel pipe pile, extending along the inner or outer circumferential surface, and joined directly or indirectly to the inner or outer circumferential surface. [2] The drilling bit according to [1], wherein the extension is joined to the inner circumferential surface or the outer circumferential surface via a wedge-shaped member interposed in the gap between the extension and the inner circumferential surface or the outer circumferential surface. [3] The drilling bit according to [1], further comprising a wedge-shaped portion interposed in the gap between the extension and the inner circumferential surface or the outer circumferential surface, wherein the extension is joined to the inner circumferential surface or the outer circumferential surface via the wedge-shaped portion. [4] The drilling bit according to any one of items [1] to [3], wherein the extension is plate-shaped and the side opposite to the inner circumferential surface or the outer circumferential surface is an inclined surface. [5] The drilling bit according to any one of [1] to [4], wherein the main body portion includes a first portion that protrudes from the end face toward the inner circumferential surface of the steel pipe pile when viewed in the axial direction, and a second portion that protrudes from the end face toward the outer circumferential surface of the steel pipe pile when viewed in the axial direction, and the extension portion is formed continuously with the first portion but not continuously with the second portion. A steel pipe pile having drilling bits described in any one of items [6], [1] to [5] joined to its axial end face, wherein a plurality of drilling bits are arranged in the circumferential direction of the steel pipe pile at the end face. [Effects of the Invention]

[0007] With the above configuration, the drilling bit can be positioned relative to the steel pipe pile by bringing the side of the extension into contact with the inner or outer circumferential surface of the steel pipe pile, thus allowing for easy and accurate setting of the protruding length of the main body from the inner or outer circumferential surface of the steel pipe pile. Furthermore, the mounting angle of the drilling bit can be easily and accurately set by bringing the extension into contact with a separate wedge-shaped member, or by forming a wedge-shaped portion in contact with the extension. Therefore, with the above configuration, the mounting accuracy of the drilling bit can be improved without complicating the construction process. [Brief explanation of the drawing]

[0008] [Figure 1] This is a six-view drawing of a drilling bit according to one embodiment of the present invention. [Figure 2] This diagram shows the drilling bit shown in Figure 1 attached to a steel pipe pile, and is a view along the line II-II in Figure 3. [Figure 3] Figure 1 shows the drilling bit attached to the steel pipe pile, and is a view along the line III-III in Figure 2. [Figure 4] This figure shows an example of a steel pipe pile configuration with the drilling bit shown in Figure 1 attached. [Figure 5] This is a six-view drawing of a modified drilling bit. [Modes for carrying out the invention]

[0009] Preferred embodiments of the present invention will be described in detail below with reference to the attached drawings. In this specification and drawings, components having substantially the same functional configuration are denoted by the same reference numerals, and redundant descriptions will be omitted.

[0010] Figure 1 is a six-view drawing of a drilling bit according to one embodiment of the present invention. Hereinafter, Figure 1 will be described as (a) top view, (b) front view, (c) bottom view, (d) left side view, (e) right side view, and (f) rear view, but the directions included in these names do not limit the direction in which the drilling bit is positioned. As shown in the figure, the drilling bit 1 includes a plate-shaped main body 2 and a plate-shaped extension 3. In the figure, the upper side is the side where the steel pipe pile is located, and the lower side is the ground side.

[0011] The main body portion 2 is the part that protrudes beyond the end face of the steel pipe pile in the axial direction of the steel pipe pile when the drilling bit 1 is attached to the steel pipe pile. The main body portion 2 also includes a protruding portion 2A that protrudes toward the inner circumferential surface of the steel pipe pile when attached to the steel pipe pile, as will be described later. In the portion where the extension portion 3 is not formed, grooves 4 and 5 are formed on the upper surface of the main body portion 2, and the main body portion 2 is joined to the end face of the steel pipe pile by welding using the grooves 4 and 5.

[0012] The extension 3 is formed on the upper side of the main body 2, continuously from the protruding portion 2A, and extends along the inner circumferential surface of the steel pipe pile when attached to it. Here, continuous formation means that they transmit stress to each other and behave as a single unit, and does not necessarily mean that the main body 2 and the extension 3 are integrally molded. Specifically, the main body 2 and the extension 3 may be integrally molded, or they may be molded separately and joined to each other by welding or bolting. As described above, both the main body 2 and the extension 3 are plate-like, but their thicknesses do not necessarily have to be the same. Not only when the main body 2 and the extension 3 are molded separately, but also when they are integrally molded, for example, the plate thickness of the extension 3 may be thinner than that of the main body 2.

[0013] The left side surface 6 of the extension 3 may be welded to the inner surface of the steel pipe pile in the same way as the main body 2 when the main body 2 is joined to the end face of the steel pipe pile by welding using grooves 4 and 5. In this case, the extension 3 is directly joined to the inner surface of the steel pipe pile. Alternatively, the extension 3 may be indirectly joined to the inner surface of the steel pipe pile via a wedge-shaped member or a wedge-shaped portion that forms part of the excavation bit, as will be described later, and both direct joining by welding and indirect joining via a wedge-shaped member or wedge-shaped portion may be formed. By joining the extension 3 to the inner surface of the steel pipe pile, the excavation bit 1 can be joined to the steel pipe pile more firmly than, for example, when only the upper surface of the main body 2 is joined to the end face of the steel pipe pile. In addition, the right side surface 7 of the extension 3 may be an inclined surface as shown in the figure. Since the side surface 7 is located on the opposite side of the inner surface of the steel pipe pile and is exposed in the ground, making the side surface 7 an inclined surface can reduce the resistance received from soil and sand during excavation.

[0014] With the configuration of the drilling bit 1 according to this embodiment as described above, the drilling bit 1 can be positioned relative to the steel pipe pile by bringing the side surface 6 of the extension 3 into contact with the inner circumferential surface of the steel pipe pile. This makes it easy and accurate to set the protruding length of the protruding portion 2A of the main body 2 from the inner circumferential surface of the steel pipe pile. Furthermore, the mounting angle of the drilling bit 1 can also be easily and accurately set by bringing the extension 3 into contact with the wedge-shaped member described later, or by forming a wedge-shaped portion in contact with the extension 3. Therefore, in this embodiment, the mounting accuracy of the drilling bit 1 can be improved without complicating the construction process.

[0015] Figures 2 and 3 show the drilling bit shown in Figure 1 attached to a steel pipe pile. The viewpoint relationships in each figure are indicated by lines II-II and III-III. In relation to Figure 1, Figure 2 corresponds to (b) front view, and Figure 3 corresponds to (a) top view. As shown, the upper surface of the main body portion 2 of the drilling bit 1, where the extension portion 3 is not formed, is joined to the axial end face 12 of the steel pipe pile 10 by a welded joint 11 formed using the grooves 4 and 5 shown in Figure 1.

[0016] As described above, in a state where the upper surface of the main body portion 2 is joined to the end surface 12 of the steel pipe pile 10, the extension portion 3 extends along the inner peripheral surface 13 of the steel pipe pile 10. As shown in FIG. 3, a wedge-shaped member 14 is inserted between the inner peripheral surface 13 and the extension portion 3. By abutting the wedge-shaped member 14 against both the inner peripheral surface 13 and the extension portion 3, the attachment angle of the excavation bit 1 can be set to an angle corresponding to the tip angle θ of the wedge-shaped member 14. Here, the attachment angle is the angle formed by the plate thickness center line of the excavation bit 1 and the circumferential tangent of the steel pipe pile 10 at the attachment position of the excavation bit 1. The wedge-shaped member 14 is joined to the inner peripheral surface 13 or the extension portion 3, or both, by, for example, fillet welding. Alternatively, instead of the wedge-shaped member 14, a wedge-shaped portion having a similar shape may be integrally formed with the extension portion 3 as a part of the excavation bit 1. In this case, the wedge-shaped portion is joined to the inner peripheral surface 13 by, for example, fillet welding. For example, when the attachment angle of the excavation bit 1 is small, a configuration in which the wedge-shaped member 14 is not inserted and the excavation bit 1 does not have a wedge-shaped portion is also possible.

[0017] By rotating the steel pipe pile 10 with the excavation bit 1 attached thereto about its axis, specifically, in either of the directions of the arrows 15 and 16 shown in FIG. 3, the ground is excavated. When the steel pipe pile 10 is rotated in the direction of the arrow 15, the earth and sand inside the steel pipe pile 10 is pushed out to the outside of the steel pipe pile 10 by the excavation bit 1, and while preventing an increase in the driving resistance due to the internal portion of the steel pipe pile 10 being blocked by the earth and sand, the driving of the steel pipe pile 10 can be advanced. As shown by the arrow 17 in FIG. 2, at this time, by making the side surface 7 of the extension portion 3, which will be located at the leading edge of the excavation, an inclined surface, the earth and sand can be allowed to escape upward, and the resistance received by the excavation bit 1 from the earth and sand can be reduced.

[0018] On the one hand, when the steel pipe pile 10 is rotated in the direction of arrow 16, the earth and sand outside the steel pipe pile are taken into the inside of the steel pipe pile 10 by the excavation bit 1. For example, after the steel pipe pile 10 is driven to a predetermined depth, the inside of the steel pipe pile 10 can be blocked with earth and sand by such rotation in this direction, and the supporting force of the steel pipe pile 10 can be increased. Note that the rotation direction of the steel pipe pile 10 is not particularly limited, and the reverse rotation process does not necessarily have to be adopted. Specifically, the steel pipe pile 10 may be rotated only in the direction of arrow 15, or may be rotated only in the direction of arrow 16, or may be rotated in both the direction of arrow 15 and the direction of arrow 16 in sequence or alternately.

[0019] FIG. 4 is a diagram showing a configuration example of a steel pipe pile to which the excavation bit shown in FIG. 1 is attached. The perspective view of FIG. 4 corresponds to the bottom view of (c) in FIG. 1 and FIG. 3. In the illustrated example, the excavation bit 1 shown in FIG. 1 and a different excavation bit 21 are attached to the steel pipe pile 10. The excavation bits 1 and 21 are both joined to the axial end face 12 of the steel pipe pile 10 and are arranged in the circumferential direction of the steel pipe pile 10. The attachment angle of the excavation bit 21 is smaller than that of the excavation bit 1, and the protruding length into the inside of the steel pipe pile 10 is also smaller. Therefore, the excavation bit 21 is not formed with an extension as described above for the excavation bit 1.

[0020] Thus, the steel pipe pile 10 may be fitted with a mixture of drilling bits 1 according to the embodiment of the present invention and drilling bits 21 that do not conform to the present invention. In the illustrated example, drilling bits 1 and drilling bits 21 are arranged alternately in groups of four at positions that divide the steel pipe pile 10 into eight equal parts in the circumferential direction. However, the number of drilling bits arranged in the circumferential direction of the steel pipe pile 10 is not limited to this example. For example, drilling bits may be arranged at positions that divide the steel pipe pile 10 into four or six equal parts in the circumferential direction. In another example, all drilling bits fitted to the steel pipe pile may be drilling bits according to the embodiment of the present invention. In this case as well, the mounting angle and protruding length may differ among the drilling bits by changing the length of the drilling bit, the tip angle of the wedge-shaped member or wedge-shaped portion, and the presence or absence of the wedge-shaped member. For example, the plate thickness of the extension may be increased when the mounting angle of the drilling bit is large or the protruding length is long, and the plate thickness of the extension may be decreased when the mounting angle of the drilling bit is small or the protruding length is short. In this case, the thickness of the main body of the drilling bit and the thickness of the extension may be different. Furthermore, the axial projection height of the steel pipe pile may also differ between each drilling bit.

[0021] In the above embodiment, an example was described in which the drilling bit protrudes to the inner circumferential surface side of the steel pipe pile, but the drilling bit may similarly protrude to the outer circumferential surface side of the steel pipe pile. That is, for example, in the example shown in Figure 1 above, the drilling bit 1 may be attached to the steel pipe pile such that the protruding portion 2A of the main body 2 protrudes to the outer circumferential surface side of the steel pipe pile. In this case, the extension 3 extends along the outer circumferential surface of the steel pipe pile and is joined directly or indirectly to the outer circumferential surface of the steel pipe pile. Alternatively, the drilling bit may protrude to both the inner and outer circumferential surfaces of the steel pipe pile. In this case, the main body of the drilling bit includes a first protruding portion that protrudes to the inner circumferential surface side of the steel pipe pile and a second protruding portion that protrudes to the outer circumferential surface side of the steel pipe pile. In this case, for example, a first extension portion that extends along the inner circumferential surface of the steel pipe pile and a second extension portion that extends along the outer circumferential surface of the steel pipe pile may be formed continuously with each of the first and second protruding portions. Alternatively, only an extension portion that extends along the inner surface of the steel pipe pile, continuous with the first protruding portion that protrudes toward the inner surface of the steel pipe pile, may be formed, and no extension portion continuous with the second protruding portion may be formed.

[0022] In the above embodiment, an example was described in which the main body 2 and extension 3 of the drilling bit 1 are plate-shaped with a substantially uniform thickness. However, the main body 2 and extension 3 may be plate-shaped with varying thickness. For example, as shown in the modified example in Figure 5, a cut-off surface 2B may be formed on the main body 2 in the portion that protrudes to the outer circumference of the steel pipe pile when attached to the steel pipe pile. Alternatively, a cut-off surface may be formed on the portion that protrudes to the inner circumference of the steel pipe pile, on the opposite side from the example in Figure 5. In addition to forming a cut-off surface, the thickness of the main body 2 and extension 3 may vary overall. For example, the thickness of the main body 2 and extension 3 may taper towards the outer circumference of the steel pipe pile, becoming thicker or thinner overall.

[0023] Furthermore, in the above embodiment, the lower end face of the main body 2 is inclined to become higher toward the outer circumference of the steel pipe pile (the height dimension of the main body 2 gradually increases), but in other examples, the lower end face of the main body 2 may be inclined in the opposite direction, becoming higher toward the inner circumference of the steel pipe pile (the height dimension of the main body 2 gradually increases). Alternatively, the lower end face of the main body 2 may not be inclined, and the height dimension of the main body 2 may be the same on both the inner and outer circumferences of the steel pipe pile.

[0024] Preferred embodiments of the present invention have been described in detail above with reference to the attached drawings, but the present invention is not limited to these examples. It will be obvious to those skilled in the art to which the present invention belongs that various modifications or alterations can be conceived within the scope of the technical idea described in the claims, and these will naturally also be understood to fall within the technical scope of the present invention. [Explanation of Symbols]

[0025] 1...Drilling bit, 2...Main body, 2A...Protruding part, 2B...Cut-off surface, 3...Extension part, 4,5...Bevel, 6,7...Side view of extension part, 10...Steel pipe pile, 11...Welded part, 12...End face, 13...Inner circumferential surface, 14...Wedge-shaped member, 15,16...Arrows indicating the direction of rotation, 17...Arrows indicating the flow of soil and sand, 21...Drilling bit, θ...Tip angle.

Claims

1. A steel pipe pile having an excavation bit joined to its axial end face, The drilling bit comprises a plate-shaped main body portion including a portion that is joined to the axial end face of the steel pipe pile and a portion that protrudes from the end face toward the inner or outer circumferential surface of the steel pipe pile when viewed in the axial direction, and an extension portion that is formed continuously only with respect to the portion of the main body portion that protrudes toward the inner or outer circumferential surface of the steel pipe pile, extends along the inner or outer circumferential surface, is joined directly or indirectly to the inner or outer circumferential surface, and together with the main body portion forms a plate-shaped member with a planar shape that is substantially L-shaped or substantially U-shaped. The extension is joined to the inner circumferential surface or the outer circumferential surface via a wedge-shaped member that is interposed in the gap between the inner circumferential surface or the outer circumferential surface and the extension, and is in contact with both the inner circumferential surface or the outer circumferential surface and the extension. A steel pipe pile in which a plurality of drilling bits are arranged in the circumferential direction of the steel pipe pile at the end face.

2. The steel pipe pile according to claim 1, wherein the extension is plate-shaped, and the side opposite to the inner circumferential surface or the outer circumferential surface is an inclined surface.

3. The main body includes a portion joined to the end face, a first portion that protrudes from the end face toward the inner circumferential surface of the steel pipe pile when viewed in the axial direction, and a second portion that protrudes from the end face toward the outer circumferential surface of the steel pipe pile when viewed in the axial direction. The steel pipe pile according to claim 1 or claim 2, wherein the extension is formed in continuity with the first portion and not in continuity with the second portion.

4. The main body includes a portion joined to the end face, a first portion that protrudes from the end face toward the inner circumferential surface of the steel pipe pile when viewed in the axial direction, and a second portion that protrudes from the end face toward the outer circumferential surface of the steel pipe pile when viewed in the axial direction. The steel pipe pile according to any one of claims 1 to 3, wherein the extension includes a first extension and a second extension formed continuously with the first and second portions, respectively.

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