Two-edge butt-welded cement drill bit

Abstract

The present invention provides a two-blade butt-welded cement drill bit, comprising a spirally extended drill bit body, and a cutting blade block connected to the end of the drill bit body. The cutting blade block includes two cutting protrusions that are symmetrically welded to each other. The cutting protrusions cooperate to form a continuously extending cutting blade ridge line at the intersection. Each cutting protrusion forms a groove that is recessed toward the drill bit body along the axial direction of the drill bit body, and the grooves of the cutting protrusions are symmetrically located on opposite sides of the cutting blade ridge line along the radial direction of the drill bit body. The cutting protrusions are combined by butt welding, so there is no need to form a support structure for the inserted drill bit, which can avoid the obstruction of the support structure and produce a larger chip removal space and a larger effective blade width. The symmetrically arranged grooves can reduce the axial resistance during drilling and reduce the load borne by the cutting blade block.

Description

Technical Field

[0001] The invention relates to a drill bit, in particular to a two-edge butt-welded cement drill bit. Background Art

[0002] Generally, drill bits used in construction are of different shapes corresponding to different power tools, such as the common straight handle or hexagonal handle. The drill bits themselves are also divided into cement drill bits, tile drill bits, metal drill bits, or universal cement drill bits, etc. according to the different objects of the work. Figure 1 At present, due to the consideration of process processing and cost, the two-edged drill bit 1 is mostly used as a universal cement drill bit, which has great versatility. However, the general two-edged cement drill bit 1 is mostly inserted, that is, there is a carbon steel support structure 13 between the drill body 11 and the cutting blade block 12. These carbon steel support structures 13 not only block chip removal, but also limit the blade width of the cutting blade block 12. In addition, the cement drill bit 1 will increase the burden of the cutting blade block 12 due to axial resistance when drilling, so there is still room for improvement. Summary of the invention

[0003] The object of the present invention is to provide a cement drill bit which does not require a carbon steel supporting structure and can reduce axial resistance when drilling.

[0004] The present invention provides a two-blade butt-welded cement drill bit, which comprises a drill body that is spirally extended and forms a plurality of spirally spaced chip grooves, and a cutting blade block that is connected to the end of the drill body along the axial direction of the drill body, wherein the cutting blade block comprises two cutting convex bodies that are symmetrically welded to each other, wherein the cutting convex bodies cooperate with each other to form a cutting blade ridge line that is continuously extended and located at the end along the axial direction of the drill body at the intersection, wherein each cutting convex body forms a groove that is concave toward the drill body along the axial direction of the drill body, and wherein the grooves of the cutting convex bodies are symmetrically located on opposite sides of the cutting blade ridge line along the radial direction of the drill body.

[0005] The two-edge butt-welded cement drill bit of the present invention, each cutting protrusion of the cutting blade block has a main blade body portion forming a first cutting edge, and a side blade body portion connected to the main blade body portion and together with the main blade body portion surrounding and defining the groove, the first cutting edges of the two main blade bodies are connected to each other, the side blade body portion forms a second cutting edge connected to the first cutting edges, and the two first cutting edges and the two second cutting edges of the cutting protrusion constitute the cutting blade ridge line.

[0006] In the two-edge butt-welded cement drill bit of the present invention, the main blade body portion of each cutting convex body also has an outer blade ridge line connected to the side blade body portion and together surrounding the groove.

[0007] In the two-edge butt-welded cement drill bit of the present invention, one end of the outer edge ridge line of each cutting convex body is connected to the first cutting edge and the second cutting edge.

[0008] In the two-edge butt-welded cement drill bit of the present invention, the main blade body portion of each cutting convex body further comprises an outer ridge line connected to the outer blade ridge line and extending in the radial direction of the drill bit body.

[0009] In the two-edge butt-welded cement drill bit of the present invention, the rake angle of the first cutting edge of each cutting convex body is a positive rake angle or a negative rake angle.

[0010] In the two-edge butt-welded cement drill bit of the present invention, the main blade body portion of each cutting convex body is connected to the side blade body portion of another cutting convex body.

[0011] The beneficial effect of the present invention is that the cutting convex body is combined by butt welding, so there is no need to form a carbon steel support structure of the inserted drill bit, which can avoid the obstruction of the support structure and generate a larger chip removal space, and the cutting convex body can also have a larger effective blade width. In addition, the symmetrically arranged grooves can reduce the axial resistance during drilling, reduce the load borne by the cutting blade block, and thus increase the life of the cement drill bit. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a bottom view showing a general two-edged drill bit;

[0013] Figure 2 is a side view illustrating an embodiment of a two-edge butt-welded cement drill bit of the present invention;

[0014] Figure 3 is a three-dimensional diagram illustrating the cutting blade block in this embodiment;

[0015] Figure 4 is a bottom view, illustrating that the cutting blade block is composed of two cutting convex bodies; and

[0016] Figure 5 It is a front view, illustrating the front view of the cutting blade block. DETAILED DESCRIPTION

[0017] The present invention is described in detail below with reference to the accompanying drawings and embodiments.

[0018] See also Figure 2 , Figure 3 ,and Figure 4, an embodiment of the two-blade butt-welded cement drill bit of the present invention comprises a spirally extending drill body 2, and a cutting blade block 3 connected to the end of the drill body 2 along the axial direction of the drill body 2. The drill body 2 forms a plurality of spirally spaced chip grooves 21. The cutting blade block 3 comprises two cutting convex bodies 4 that are symmetrically welded to each other. Each cutting convex body 4 has a main blade body portion 41, and a side blade body portion 42 connected to the main blade body portion 41. The main blade body portion 41 and the side blade body portion 42 together surround and define a groove 43 that is recessed toward the drill body 2 along the axial direction of the drill body 2. The main blade body portion 41 has a first cutting edge 411, an outer blade ridge line 412 that is connected to the side blade body portion 42 and surrounds the groove 43, and an outer blade ridge line 413 that is connected to the outer blade ridge line 412 and extends along the radial direction of the drill body 2. The side blade body 42 has a second cutting edge 421 connected to the first cutting edge 411. One end of the outer blade ridgeline 412 is connected to both the first cutting edge 411 and the second cutting edge 421.

[0019] See also Figure 3 , Figure 4 ,and Figure 5 , the cutting convex body 4 is combined by welding without the need for other supporting structures. In addition, the main blade body 41 of each cutting convex body 4 is connected to the side blade body 42 of another cutting convex body 4, and the two first cutting edges 411 of the cutting convex body 4 are connected to each other, and the two first cutting edges 411 and the two second cutting edges 421 form a continuously bent and extended cutting edge ridge line 44 located at the end along the axial direction of the drill body 2. The grooves 43 of the cutting convex body 4 are symmetrically located on opposite sides of the cutting edge ridge line 44 along the radial direction of the drill body 2.

[0020] This embodiment adopts a butt-welding design, so there is no need to set up a support structure like a general insert drill bit. Without the obstruction of the support structure, a larger chip removal space can be generated, and the cutting protrusion 4 can also have a larger blade width, thereby improving chip removal and cutting capabilities. On the other hand, the symmetrically arranged grooves 43 can reduce the axial resistance during drilling in this embodiment, reduce the load borne by the cutting blade block 3, and thus increase the life of the cement drill bit of this embodiment. The design of the grooves 43 can be adjusted according to demand, so that the front angle of the first cutting edge 411 can be a positive angle or a negative angle according to demand. The former can make the cutting ability more excellent, while the latter can greatly increase the strength of the first cutting edge 411, greatly increasing the design flexibility and versatility.

[0021] In summary, the present embodiment adopts a butt-welded two-blade design, which can be applied to cement drill bits and universal cement drill bits, and does not require carbon steel or other supporting structures, thereby increasing the chip removal space and the effective blade width. The groove 43 can also reduce the axial resistance during drilling, thereby extending the life of the cement drill bit of this embodiment, so the purpose of the present invention can indeed be achieved.

[0022] The above description is only a preferred embodiment of the present invention, but it is not intended to limit the scope of the present invention. Any person familiar with this technology can make further improvements and changes on this basis without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be based on the scope defined by the claims of this application.

Claims

1. A two-edge butt-welded cement drill bit, characterized in that: The two-blade butt-welded cement drill bit includes a drill body that extends spirally and forms a plurality of spirally spaced chip grooves, and a cutting blade block that is connected to the end of the drill body along the axial direction of the drill body, the cutting blade block includes two cutting protrusions that are symmetrically welded to each other, the cutting protrusions cooperate to form a cutting blade ridge that extends continuously and is located at the end along the axial direction of the drill body at the intersection, each cutting protrusion forms a groove that is recessed toward the drill body along the axial direction of the drill body, and the grooves of the cutting protrusions are respectively located on opposite sides of the cutting blade ridge symmetrically along the radial direction of the drill body, each cutting protrusion of the cutting blade block has a main blade body portion that forms a first cutting edge, and a side blade body portion that is connected to the main blade body portion and together with the main blade body portion surrounds and defines the groove, the first cutting edges of the two main blade bodies are connected to each other, the side blade body portion forms a second cutting edge that connects the first cutting edge, and the two first cutting edges and the two second cutting edges of the cutting protrusion constitute the cutting blade ridge.

2. The two-edge butt-welded cement drill bit according to claim 1, characterized in that: The main blade portion of each cutting protrusion also has an outer blade ridge line connected to the side blade portions to jointly surround the groove.

3. The two-edge butt-welded cement drill bit according to claim 2, characterized in that: One end of the outer edge ridge line of each cutting convex body is connected to the first cutting edge and the second cutting edge.

4. The two-edge butt-welded cement drill bit according to claim 3, characterized in that: The main blade portion of each cutting convex body also has an outer ridge line connected to the outer blade ridge line and extending in the radial direction of the drill body.

5. The two-edge butt-welded cement drill bit according to claim 1, characterized in that: The rake angle of the first cutting edge of each cutting convex body is a positive rake angle or a negative rake angle.

6. The two-edge butt-welded cement drill bit according to claim 1, characterized in that: The main blade portion of each cutting convex body is connected to the side blade portion of another cutting convex body.

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