Flat drill for metal processing

Abstract

The utility model discloses a flat drill for metal machining, and relates to the technical field of drill bits, the flat drill comprises a handle part and a flat drilling part, a transition part is arranged between the handle part and the drilling part, the drilling part is provided with two symmetrically-arranged cutting edges, each cutting edge is provided with an arc edge face and a chip removal face, and the arc edge faces and the chip removal faces are arranged in parallel. The chip removal face is arranged in the axial direction of the handle part, a guide part is arranged at the end, away from the transition part, of the drilling part, and the guide part and the handle part are concentric. The flat drill for metal machining is suitable for machining of low-hardness metal, the concentricity of the drill bit during drilling is guaranteed, and the chip removal efficiency can be further improved.

Description

Technical Field

[0001] The present application relates to the technical field of drill bits, and in particular to a flat drill for metal processing. Background Art

[0002] The most commonly used drilling tool at present is the standard twist drill. When the standard twist drill expands the original hole, it mainly relies on the positioning accuracy of the processing equipment to ensure the concentricity of the original hole and the expanded hole. In addition, for low-hardness metal materials, the chip removal space requirements are higher. The standard twist drill retains the cylindrical blade structure, and the cylindrical blade is connected to the arc avoidance groove. The chip removal space is relatively limited and the chip removal efficiency is low. Utility Model Content

[0003] The present application aims to solve at least one of the above technical problems in the prior art to a certain extent. To this end, the present application provides a flat drill for metal processing, which is suitable for processing low-hardness metals, ensures the concentricity of the drill bit during drilling, and can further improve the chip removal efficiency.

[0004] The flat drill for metal processing described in the embodiment of the present application includes a shank and a flat drilling portion, a transition portion is provided between the shank and the drilling portion, the drilling portion has two symmetrically arranged cutting edges, the cutting edges have a circular arc blade surface and a chip removal surface, the chip removal surface is arranged along the axial direction of the shank, and a guide portion is provided at one end of the drilling portion away from the transition portion, and the guide portion is concentric with the shank.

[0005] According to the flat drill for metal processing described in the embodiment of the present application, the cross-sectional width h of the circular arc blade surface is one tenth of the diameter of the circle where the circular arc blade surface is located, and the cross-sectional width H of the cutting edge is one third of the diameter of the shank.

[0006] According to the flat drill for metal processing described in the embodiment of the present application, the chip removal surface is a plane, and the angle B between the chip removal surface and the flat surface of the drilling portion is in the range of 100° to 170°.

[0007] According to the flat drill for metal processing described in the embodiment of the present application, the ratio between the radius of the circular arc blade surface and the cross-sectional width H of the cutting edge is greater than 2.

[0008] According to the flat drill for metal processing described in the embodiment of the present application, the guide portion is cylindrical, and the diameter of the guide portion is the same as the cross-sectional width H of the cutting edge.

[0009] According to the flat drill for metal processing described in the embodiment of the present application, a first guiding bevel is provided between the guide portion and the drilling portion, and an angle D between the first guiding bevel and the central axis of the shank is in the range of 30° to 90°.

[0010] According to the flat drill for metal processing described in the embodiment of the present application, a guide cone is provided at the end of the guide portion, and the angle E between the conical surface of the guide cone and the central axis of the shank is in the range of 30° to 90°.

[0011] According to the flat drill for metal processing described in the embodiment of the present application, the length of the guide portion is smaller than the length of the drilling portion.

[0012] According to the flat drill for metal processing described in the embodiment of the present application, the transition portion has a second guiding bevel, and the angle C between the second guiding bevel and the central axis of the shank is in the range of 20° to 45°.

[0013] According to the flat drill for metal processing described in the embodiment of the present application, the diameter of the circular arc blade surface is equal to the diameter of the shank.

[0014] The above-mentioned flat drill for metal processing has at least the following beneficial effects: there is no drill bit for low-hardness metal materials in the prior art. When the existing twist drill bit has difficulty in chip removal when drilling low-hardness metal materials, the present application provides a flat drill that can be used for low-hardness metal materials. By designing the drilling part to be flat, the strength of the arc blade surface can be enhanced and the service life of the blade surface can be increased. In addition, the flat drill of the present application has better chip removal efficiency during drilling, avoiding the occurrence of damage such as drill bit breakage. In addition, when the flat drill of the present application is used for secondary processing of microholes, the diameter of the guide part is set to the same size as the diameter of the microhole. The guide part can be inserted into the microhole during drilling, which better ensures the concentricity of the secondary hole expansion and the microhole and improves the accuracy of hole expansion. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The present application is further described below with reference to the accompanying drawings and embodiments;

[0016] Figure 1 It is a structural front view of an embodiment of the present application;

[0017] Figure 2 is a bottom view of the structure of an embodiment of the present application;

[0018] Figure 3 In the embodiment of the present application, Figure 1 A magnified schematic diagram of center A. DETAILED DESCRIPTION

[0019] This section will describe in detail the specific embodiments of the present application. The preferred embodiments of the present application are shown in the accompanying drawings. The purpose of the accompanying drawings is to supplement the description of the text part of the specification with graphics, so that people can intuitively and vividly understand each technical feature and the overall technical solution of the present application, but it cannot be understood as a limitation on the scope of protection of the present application.

[0020] In the description of the present application, it should be understood that descriptions involving orientation, such as up, down, front, back, left, right, etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0021] In the description of this application, "several" means one or more, "more" means more than two, "greater than", "less than", "exceed", etc. are understood to exclude the number itself, and "above", "below", "within", etc. are understood to include the number itself. If there is a description of "first" or "second", it is only used for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0022] In the description of this application, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in this application based on the specific content of the technical solution.

[0023] The most commonly used drilling tool at present is the standard twist drill bit, which is a tool that drills a circular hole in a workpiece by rotating and cutting relative to a fixed axis. The twist drill is a simple shank + spiral blade structure; it is named because its chip groove is spiral and resembles a twist. The spiral groove generally has 2, 3 or more grooves, but 2 grooves are the most common. The twist drill can be clamped on a manual or electric handheld drilling tool or a drilling machine, milling machine, lathe or even a machining center. The drill bit material is generally high-speed tool steel or cemented carbide. When the standard twist drill expands the original hole, it mainly relies on the positioning accuracy of the processing equipment to ensure the concentricity of the original hole and the expanded hole. In addition, for low-hardness metal materials, the chip removal space is required to be higher. The standard twist drill retains the cylindrical blade structure, and the cylindrical blade is connected to the arc avoidance groove. The chip removal space is relatively limited and the chip removal efficiency is low.

[0024] Reference Figure 1 In order to solve the above problems, the present application provides a flat drill for metal processing, which specifically includes a shank 100 and a flat drilling portion, a transition portion 110 is arranged between the shank 100 and the drilling portion, the drilling portion has two symmetrically arranged cutting edges 120, the cutting edge 120 has an arc blade surface 121 and a chip removal surface 122, the chip removal surface 122 is arranged along the axial direction of the shank 100, and a guide portion 130 is arranged at one end of the drilling portion away from the transition portion 110, and the guide portion 130 is concentric with the shank 100.

[0025] It should be noted that the flat drill of the present application is also made of high-speed tool steel or cemented carbide to ensure that it has sufficient hardness for metal processing. There is no drill bit for low-hardness metal materials in the prior art. When the existing twist drill bit is used to drill low-hardness metal materials, it is inconvenient to remove chips. The present application provides a flat drill that can be used for low-hardness metal materials. By designing the drilling part to be flat, the strength of the arc blade surface 121 can be strengthened and the service life of the blade surface can be increased. In addition, the flat drill of the present application has better chip removal efficiency during drilling, avoiding the occurrence of damage such as drill bit breakage. In addition, when the flat drill of the present application is used for secondary processing of microholes, the diameter of the guide part 130 is set to be the same as the diameter of the microhole. The guide part 130 can be inserted into the microhole during drilling, which better ensures the concentricity of the secondary hole expansion and the microhole, and improves the accuracy of hole expansion.

[0026] It should be noted that the existing flat drill is generally used for drilling holes in wood, wherein the cutting portion of the existing flat drill is ground into a flat body, the main cutting edge is ground with a front angle and a back angle to form a transverse edge; the secondary cutting edge is ground with a back angle and a secondary deflection angle to control the drilling diameter, and the existing flat drill has a small front angle, no spiral groove, and difficult chip removal, but is simple to manufacture and low in cost, and is widely used in the processing of small holes with a diameter of less than 1 mm.

[0027] The present application is improved on the existing basis. The flat drill of the present application removes the front angle, the chisel edge, the back angle and the secondary deflection angle, and is improved to be used for processing low-hardness metals. The heat treatment process of the flat drill in the present application mainly includes two steps, namely heating treatment and cooling treatment. First, the flat drill is placed in a heating furnace for heating treatment, and the heating temperature is generally controlled between 840C and 930C to ensure uniform heating of the steel. During the heating process, care should be taken to avoid overheating and oxidation on the surface of the steel. After heating, the flat drill needs to be cooled immediately to achieve the required hardness and toughness. The cooling treatment usually adopts oil quenching or air cooling. Among them, oil quenching is to quickly immerse the flat drill in pre-heated quenching oil to quickly cool the steel. And air cooling is to place the flat drill in the air for natural cooling. The choice of cooling treatment should be determined according to different steel types and requirements. After heat treatment, the grain structure of the flat drill will change, thereby improving its hardness and toughness. At the same time, heat treatment can also eliminate stress inside the steel and improve its mechanical properties and fatigue resistance. In addition, heat treatment can also improve the cutting performance and wear resistance of the flat drill and extend its service life.

[0028] Further, such as Figure 2As shown, the cross-sectional width h of the arc blade surface 121 of the present application is one tenth of the diameter of the circle where the arc blade surface 121 is located. Within this range, the cutting effect of the arc blade surface 121 is better and the service life is longer. The cross-sectional width H of the cutting edge 120 is half the diameter of the shank 100, so that the cutting edge 120 has sufficient rigidity.

[0029] Furthermore, in the embodiment of the present application, the chip removal surface 122 is a plane, and the angle B between the chip removal surface 122 and the flat surface of the drilling portion is in the range of 100° to 170°. Within this range, the chip removal effect of the chip removal surface 122 is better and the chip removal efficiency is also faster. In the preferred embodiment of the present application, the angle B between the chip removal surface 122 and the flat surface of the drilling portion is preferably in the range of 105°. Of course, the angle B can also be any value within the above range.

[0030] Furthermore, the ratio between the radius of the circular blade surface 121 and the cross-sectional width H of the cutting edge 120 is greater than 2, so that the cutting effect of the circular blade surface 121 is better and the wear can be reduced during drilling.

[0031] Furthermore, the guide portion 130 is cylindrical, and the diameter of the guide portion 130 is the same as the cross-sectional width H of the cutting edge 120, so that when expanding the hole and drilling are performed, the guide portion 130 also has sufficient rigidity to ensure that the guide portion 130 is always located in the microhole during the drilling process, so that the guide portion 130 has sufficient rigidity to withstand a large load, so that the cutting edge 120 is concentric with the microhole during the drilling process, thereby improving the drilling accuracy.

[0032] Furthermore, a first guiding bevel 123 is provided between the guide portion 130 and the drilling portion. The angle D between the first guiding bevel 123 and the central axis of the shank 100 is in the range of 30° to 90°. The first guiding bevel 123 is used to slowly introduce the drilling portion into the microhole for further hole expansion, thereby alleviating the impact of drilling on the workpiece. In addition, in the embodiment of the present application, the angle D is preferably 60°.

[0033] Furthermore, a guide cone 131 is provided at the end of the guide portion 130, and an angle E between the conical surface of the guide cone 131 and the central axis of the handle 100 is in the range of 30° to 90°. In the embodiment of the present application, the angle E is preferably 60°.

[0034] Furthermore, the length of the guide portion 130 is shorter than the length of the drilling portion. If the guide portion 130 is too long, the coaxiality will be affected. In actual use, within the above range, the guide portion 130 has the best effect.

[0035] Furthermore, the transition portion 110 has a second guiding slope, and an angle C between the second guiding slope and the central axis of the handle 100 is in the range of 20° to 45°. In the embodiment of the present application, the angle C is preferably 30°.

[0036] In some other embodiments, the diameter of the arc blade surface 121 is equal to the diameter of the shank 100 , so as to facilitate the processing and manufacturing of the drilling portion.

[0037] On the whole, the flat drill itself can effectively solve the problem of inconvenience in chip removal when the existing drill bit is used to drill low-hardness metal materials. By designing the drilling part to be flat, on the one hand, the strength of the arc blade surface 121 can be enhanced and the service life of the blade surface can be improved. On the other hand, sufficient chip removal space can be left for the chip removal surface 122, so that the flat drill of the present application has better chip removal efficiency during drilling and avoids damage such as drill bit breakage. In addition, the guide part 130 can better ensure the concentricity of the secondary hole expansion and the microhole, thereby improving the accuracy of hole expansion.

[0038] The embodiments of the present application are described in detail above in conjunction with the accompanying drawings, but the present application is not limited to the above embodiments, and various changes can be made within the knowledge scope of ordinary technicians in the technical field without departing from the purpose of the present application.

Claims

1. A flat drill for metal processing, characterized in that: The invention comprises a shank (100) and a flat drilling portion, wherein a transition portion (110) is arranged between the shank (100) and the drilling portion, the drilling portion has two symmetrically arranged cutting edges (120), the cutting edges (120) have arc blade surfaces (121) and chip removal surfaces (122), the chip removal surfaces (122) are arranged along the axial direction of the shank (100), and a guide portion (130) is arranged at one end of the drilling portion away from the transition portion (110), and the guide portion (130) is concentric with the shank (100).

2. The flat drill for metal processing according to claim 1, characterized in that: The cross-sectional width h of the circular arc blade surface (121) is one tenth of the diameter of the circle where the circular arc blade surface (121) is located, and the cross-sectional width H of the cutting edge (120) is one third of the diameter of the shank (100).

3. The flat drill for metal processing according to claim 1, characterized in that: The chip removal surface (122) is a plane, and the included angle B between the chip removal surface (122) and the flat surface of the drilling portion is in the range of 100° to 170°.

4. The flat drill for metal processing according to claim 1, characterized in that: The ratio between the radius of the circular arc blade surface (121) and the cross-sectional width H of the cutting edge (120) is greater than 2.

5. The flat drill for metal processing according to claim 1, characterized in that: The guide portion (130) is cylindrical, and the diameter of the guide portion (130) is the same as the cross-sectional width H of the cutting edge (120).

6. The flat drill for metal processing according to claim 1, characterized in that: A first guiding bevel (123) is provided between the guiding portion (130) and the drilling portion, and an angle D between the first guiding bevel (123) and the central axis of the shank (100) is in the range of 30° to 90°.

7. The flat drill for metal processing according to claim 1, characterized in that: A guide cone (131) is provided at the end of the guide portion (130), and an included angle E between the cone surface of the guide cone (131) and the central axis of the handle (100) is in the range of 30° to 90°.

8. The flat drill for metal processing according to claim 1, characterized in that: The length of the guide portion (130) is smaller than the length of the drilling portion.

9. The flat drill for metal processing according to claim 1, characterized in that: The transition portion (110) has a second guiding slope, and an angle C between the second guiding slope and the central axis of the handle (100) is in the range of 20° to 45°.

10. The flat drill for metal processing according to claim 1, characterized in that: The diameter of the circular arc blade surface (121) is equal to the diameter of the shank (100).

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