Durable drill bit

Abstract

A durable drill bit includes a shank, a cutting bar, and a cutting head including two main flanks for forming chisel edges, one of the main flanks having a tilt angle of 45 degrees and the other of the main flanks having a tilt angle of 60 degrees, each main flank having a main cutting edge formed at an end face and a secondary cutting edge provided at an outer periphery, the tail end of the knife handle is connected with an extension rod, the extension rod is provided with a locking unit which has a preset shape and can retract after being extruded, and the tail end of the knife handle is provided with a locking node which allows the extruded locking unit to rebound to the preset shape and be combined with the locking unit. The drill bit has the advantages that drilling resistance in the whole drilling process can be reduced due to the fact that the angles of the two main rear tool faces of the cutting head are different, impact force of the drill bit is higher, meanwhile, the combination mode of the extension rod and the tool handle does not need to be clamped through auxiliary tools such as a vice, and tightness of threaded connection is guaranteed. And the condition of disjunction caused by impact force does not exist.

Description

Technical Field

[0001] The utility model relates to the technical field of high-efficiency, high-speed and precision cutting tools, in particular to a durable drill bit. Background Art

[0002] A drill bit is a general term for a type of cutting tool used to drill through holes or blind holes in solid materials and to ream existing holes. Its conventional types include: twist drill, flat drill, deep hole drill, reamer, center drill, etc.

[0003] Publication (Announcement) No.: CN217474920 discloses a high-strength extended twist drill, which includes a twist drill bit and several extension pieces; the tail of the twist drill bit is connected with a mounting piece; one of the several extension pieces is connected to the bottom of the mounting piece; the other extension pieces among the several extension pieces are sequentially connected to the bottom of the previous extension piece; fixing grooves are arranged on the outer walls of the mounting piece and the several extension pieces. This drill bit increases the use length through the extension pieces, thus solving the defect that the drill bit length is insufficient under a single size, but there are defects. That is, the extension pieces are connected to the drill bit and adjacent extension pieces in a threaded connection manner. Since the drill bit is in a rotating state during work, the threaded connection method will cause looseness at the connection, and the looseness will affect the stability of the drill bit during work, that is, the sizes of the holes processed are inconsistent, resulting in the scrapping of the items to be processed. Summary of the Utility Model

[0004] The utility model aims to solve the above-mentioned disadvantages of the prior art and provides a durable drill bit to solve the above problems.

[0005] The technical solution adopted by the utility model to solve its technical problems: This durable drill bit includes a tool shank, a cutting rod, and a cutting head. The cutting head includes two major flank faces for forming the chisel edge, the inclination angle of one major flank face is 45°, and the inclination angle of the other major flank face is 60°. Each major flank face has a main cutting edge formed at the end face and a secondary cutting edge arranged at the outer periphery. The tail end of the tool shank is connected with an extension rod, and a locking unit with a preset shape and capable of retracting under extrusion is arranged on the extension rod. A locking node is arranged at the tail end of the tool shank, which allows the locking unit that has been extruded to rebound to the preset shape and combine with the locking unit.

[0006] Furthermore, an insertion cavity extending along the length direction of the tool shank and allowing part of the extension rod to enter is arranged on the bottom surface of the tail end of the tool shank. The insertion cavity is vertically arranged and interconnected with the locking node. The locking unit is arranged on the part of the extension rod that enters the insertion cavity and is extruded by the inner wall of the insertion cavity when following the extension rod into it.

[0007] Further improvement: The locking nodes penetrate through the handle and there are two of them, which include a surrounding wall formed at the tail end of the handle and a resilient space defined within the surrounding wall and allowing the locking unit to rebound to a preset shape. The surrounding wall abuts against the locking unit when the locking unit enters the resilient space.

[0008] Further improvement: The extension rod includes a main body and an extension body extending from the main body and entering the insertion cavity. The outer diameter of the main body is the same as that of the handle. An accommodation cavity is provided on the extension body and is aligned with the extending direction of the locking node. The locking unit is arranged in the accommodation cavity and combines with the locking node when the extension body enters the insertion cavity.

[0009] Further improvement: The locking unit includes two insertion posts and a spring for connecting the two insertion posts. The two insertion posts and the spring are all placed in the accommodation cavity. The accommodation cavity has a left opening and a right opening on the extension body. Both the left opening and the right opening are used for the outer ends of the corresponding insertion posts to be exposed outside the accommodation cavity and combine with the corresponding locking nodes when the extension body enters the insertion cavity.

[0010] Further improvement: The outer end of the insertion post has an inclined surface obtained by cutting. The inclined surface contacts the inner edge of the surrounding wall when the extension rod moves in the direction away from the assembly direction, and allows an extrusion force that squeezes the insertion post to move inward to be generated through the contact.

[0011] Further improvement: The upper end of the extension body is provided with an installation cavity that is vertically arranged and communicates with the accommodation cavity. A connecting column is threadedly connected in the installation cavity. A limiting insertion piece extending into the accommodation cavity is provided on the lower bottom surface of the connecting column. The limiting insertion piece is inserted into the pitch formed by the spring.

[0012] Further improvement: At least one groove is provided on the outer peripheral surface of the handle, and an elastic ring is arranged in the groove.

[0013] The beneficial effects of the present utility model are:

[0014] In the present utility model, the setting that the two main flank angles of the cutting head are different can reduce the drilling resistance during the entire drilling process, thereby making the impact force of the drill bit stronger, further improving the drilling efficiency. At the same time, the combination method of the extension rod and the handle is more convenient than the traditional combination method, and it does not require the use of auxiliary tools such as vises to clamp to ensure the tightness of the threaded connection, nor does it have the situation of becoming disconnected under the influence of the impact force during the operation of the drill bit. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a schematic structural diagram of the present utility model;

[0016] Figure 2 is a full-sectional structural diagram between the extension rods of the present utility model. Detailed implementation mode

[0017] The present utility model will be further described below in conjunction with the accompanying drawings:

[0018] Referring to the accompanying drawings: This durable drill bit includes a shank 1, a cutting rod 2, and a cutting head 3. The cutting head 3 includes two main flank faces 31 for forming the chisel edge. The inclination angle of one main flank face 31 is 45°, and the inclination angle of the other main flank face 31 is 60°. Each main flank face 31 has a main cutting edge formed at the end face and a secondary cutting edge provided at the outer periphery. The tail end of the shank 1 is connected with an extension rod 4. The extension rod 4 is provided with a locking unit 5 having a preset shape and capable of retracting under extrusion. A locking node 6 is provided at the tail end of the shank 1, which allows the locking unit 5 that has been extruded to rebound to the preset shape and combine with the locking unit 5. The principle of the present utility model is that the cutting head 3 has a point angle of 105°, but the two main flank faces 31 constituting the point angle present two different inclination angles, that is, the inclination angle of one main flank face 31 is 45°, and the inclination angle of the other main flank face 31 is 60°. After the chisel edge contacts the workpiece, the angle difference of the inclination angles is used to make one main flank face 31 contact the workpiece first. After drilling to a certain depth, the other main flank face 31 contacts the workpiece, and the whole process is the same. Such a method can reduce the drilling resistance during the whole drilling process, so that the impact force of the drill bit is stronger, thereby improving the drilling efficiency and work efficiency. At the same time, the use length of the drill bit is increased through the extension rod 4, and the combination method of the extension rod 4 and the shank 1 is more convenient than the traditional combination method, and it is not necessary to use auxiliary tools such as vises to clamp to ensure the tightness of the threaded connection. At the same time, there is no situation of disconnection affected by the impact force during the operation of the drill bit.

[0019] An insertion cavity 11 extending along the length direction of the shank 1 and allowing part of the extension rod 4 to enter is provided on the bottom surface of the tail end of the shank 1. The insertion cavity 11 is vertically arranged and communicated with the locking node 6. The locking unit 5 is arranged on the part of the extension rod 4 that enters the insertion cavity 11 and is extruded by the inner wall of the insertion cavity 11 when following the extension rod 4 into it. Such a setting makes the combination of the shank 1 and the extension rod 4 complete, and the inner wall of the insertion cavity 11 can also be used to extrude the locking unit 5, that is, the length dimension of the locking unit 5 is reduced to a length adapted to the inner diameter dimension of the insertion cavity 11, so as to avoid interference during assembly, and when the locking unit 5 reaches the position of the locking node 6, the extrusion of the locking unit 5 is released, so that the locking unit 5 returns to the preset shape and realizes the combination with the locking node 6, thereby completing the combination of the extension rod 4 and the shank 1.

[0020] The locking node 6 penetrates through the tool shank 1 and there are two of them. It includes a surrounding wall 61 formed at the tail end of the tool shank 1, and a resilient space 62 defined within the surrounding wall 61 and allowing the locking unit 5 to rebound to a preset shape. The surrounding wall 61 abuts against the locking unit 5 when the locking unit 5 enters the resilient space 62. When the locking unit 5 reaches the resilient space 62 of the locking node 6, the locking unit 5 is freely released from the constrained state of being squeezed by the inner wall of the insertion cavity 11, that is, it resumes to the preset shape under its resilient performance. The surrounding wall 61 then abuts against the locking unit 5 after the locking unit 5 resumes to the preset shape, so that the locking unit 5 prevents the locking unit 5 from detaching from the locking node 6 without a reverse acting force. In this embodiment, the locking node 6 is shown as a through hole on the tool shank 1. The hole wall of the through hole forms the surrounding wall 61, and the space allowing the locking unit 5 to pass through forms the resilient space 62. That is, the through hole also enables part of the locking unit 5 to be exposed after the locking unit 5 is combined with the locking node 6. Then, when releasing the combination of the tool shank 1 and the extension rod 4, the operator can apply a squeezing force to the locking unit 5 to make the locking unit 5 detach from the locking node 6, and when clamping the extension rod 4 to the working equipment, just avoid the locking unit 5.

[0021] The extension rod 4 includes a main body 41 and an extension body 42 extending from the main body 41 and entering the insertion cavity 11. The outer diameter of the main body 41 is the same as that of the tool shank 1. An accommodation cavity 42-a is provided on the extension body 42 and is aligned with the extending direction of the locking node 6. The locking unit 5 is arranged in the accommodation cavity 42-a and is combined with the locking node 6 when the extension body 42 enters the insertion cavity 11. Such a setting makes the overall integrity good when the extension rod 4 is combined with the drill bit. The extension body 42, as the part entering the insertion cavity 11, has an outer diameter dimension adapted to the inner diameter dimension of the insertion cavity 11. The accommodation cavity 42-a is used to define the position of the locking unit 5 on the extension rod 4, so as to realize the combination of the locking unit 5 and the locking node 6 when the extension body 42 enters the insertion cavity 11. At the same time, an insertion cavity 11 is also provided on the bottom surface of the main body 41, that is, used to realize the connection of two extension rods 4.

[0022] The locking unit 5 includes two insertion posts 51 and a spring 52 for connecting the two insertion posts 51. The two insertion posts 51 and the spring 52 are all placed in the accommodation cavity 42-a. The accommodation cavity 42-a has a left opening 42-a1 and a right opening 42-a2 on the extension body 42. Both the left opening 42-a1 and the right opening 42-a2 are used for the outer ends of the corresponding insertion posts 51 to be exposed outside the accommodation cavity 42-a and to be combined with the corresponding locking nodes 6 when the extension body 42 enters the insertion cavity 11. Such a setting enables both insertion posts 51 to have the retraction function when being squeezed by the spring 52, and when both insertion posts 51 are squeezed simultaneously, they can move inward simultaneously, and the spring 52 will not be compressed and deformed due to the rotation speed. The left opening 42-a1 and the right opening 42-a2 enable the corresponding insertion posts 51 to be exposed outside, and the exposed parts are placed inside the locking nodes 6.

[0023] The upper end of the extension body 42 is provided with an installation cavity 42-b that is vertically arranged and communicated with the accommodation cavity 42-a. A connecting column 7 is threadedly connected in the installation cavity 42-b. A limiting insertion piece 71 extending into the accommodation cavity 42-a is provided on the lower bottom surface of the connecting column 7. The limiting insertion piece 71 is inserted into the pitch formed by the spring 52. Such a setting is used to limit the spring 52 in the accommodation cavity 42-b, that is, to prevent the spring 52 from moving, so as to prevent the insertion post 51 from moving in a single direction when being subjected to a squeezing force.

[0024] At least one groove 12 is provided on the outer peripheral surface of the tool handle 1, and an elastic ring 8 is provided in the groove 12, which can effectively reduce the impact force when the drill bit drills during use, thereby reducing the damage to the drill bit, avoiding the fracture of the drill bit during drilling, and prolonging the service life.

[0025] Although the present utility model has been illustrated and described by referring to the preferred embodiments, those of ordinary skill in the art should understand that various changes in form and details can be made within the scope of the claims.

Claims

1. A durable drill bit, comprising a shank (1), a cutting rod (2), and a cutting head (3), characterized in that: The cutting head (3) comprises two main flank faces (31) for forming a transverse edge, wherein the inclination angle of one of the main flank faces (31) is 45° and the inclination angle of the other main flank face (31) is 60°, each of the main flank faces (31) having a main cutting edge formed at an end face and a secondary cutting edge arranged at an outer periphery, the rear end of the tool holder (1) is connected to an extension rod (4), the extension rod (4) being provided with a locking unit (5) having a preset shape and being retractable when squeezed, and the rear end of the tool holder (1) being provided with a locking node (6) for allowing the squeezed locking unit (5) to rebound to a preset shape and for combining with the locking unit (5).

2. The durable drill bit according to claim 1, characterized in that: An insertion cavity (11) is provided on the lower bottom surface of the rear end of the knife handle (1), extending along the length direction of the knife handle (1) and allowing a portion of the extension rod (4) to enter. The insertion cavity (11) and the locking node (6) are arranged vertically and communicate with each other. The locking unit (5) is arranged on the portion of the extension rod (4) that enters the insertion cavity (11) and is squeezed by the inner wall of the insertion cavity (11) when following the extension rod (4) to enter.

3. The durable drill bit according to claim 2, characterized in that: The locking node (6) passes through the knife handle (1) and is formed in two parts, comprising an enclosing wall (61) formed on the rear end of the knife handle (1), and a rebound space (62) defined within the enclosing wall (61) and allowing the locking unit (5) to rebound to a preset shape, wherein the enclosing wall (61) abuts against the locking unit (5) when the locking unit (5) enters the rebound space (62).

4. The durable drill bit according to claim 3, characterized in that: The extension rod (4) comprises a main body (41) and an extension body (42) extending from the main body (41) and entering into the insertion cavity (11); the outer diameter of the main body (41) is consistent with the outer diameter of the knife handle (1); the extension body (42) is provided with a receiving cavity (42-a) which is consistent with the extension direction of the locking node (6); the locking unit (5) is arranged in the receiving cavity (42-a) and is combined with the locking node (6) when the extension body (42) enters into the insertion cavity (11).

5. The durable drill bit according to claim 4, characterized in that: The locking unit (5) comprises two plug posts (51) and a spring (52) for connecting the two plug posts (51); the two plug posts (51) and the spring (52) are both placed in the accommodating cavity (42-a); the accommodating cavity (42-a) is provided with a left opening (42-a1) and a right opening (42-a2) on the extension body (42); the left opening (42-a1) and the right opening (42-a2) are both used to allow the outer ends of the corresponding plug posts (51) to be exposed outside the accommodating cavity (42-a) and to be combined with the corresponding locking node (6) when the extension body (42) enters into the plug cavity (11).

6. The durable drill bit according to claim 5, characterized in that: The upper end of the extension body (42) is provided with a mounting cavity (42-b) which is arranged vertically with and communicates with the accommodating cavity (42-a); a connecting column (7) is threadedly connected to the mounting cavity (42-b); a limiting insert (71) extending into the accommodating cavity (42-a) is provided on the lower bottom surface of the connecting column (7); the limiting insert (71) is inserted into the pitch formed by the spring (52).

7. The durable drill bit according to claim 1, characterized in that: At least one groove (12) is provided on the outer peripheral surface of the knife handle (1), and an elastic ring (8) is provided in the groove (12).

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