Blank and cutting tool with helical rake face of superhard material

Abstract

A green body made of a superhard material, intended to be secured to a base body, capable of being machined into a cutting edge of a tool, comprising a first side and a second side, both twisted at a set helix angle. After the green body is fixed on the base body, the green body is processed into blade parts for cutting, such as a main cutting blade and a central part cutting blade, and the blade parts are positioned on the same green body made of the superhard material. The green body of the present invention is applied to the machining of a cutting edge of a tool, and has a continuous and complete center cutting edge formed from a superhard material on the center of rotation, thereby improving the machining precision and machining efficiency, improving the strength of the center, and prolonging the life during the implementation of cutting, compared to conventional tools. And the overall cutting performance of the cutter is obviously improved.

Description

[0001] The present invention is a divisional application filed based on the original application with application date of March 30, 2020, application number 202010240055.5, and invention name “blank and cutting tool with spiral superhard material front cutting edge”. Technical Field

[0002] The invention relates to a cutting tool, in particular to a cutting tool with a spiral superhard material front cutting surface. Background Art

[0003] Polycrystalline diamond (PCD) tools and cubic boron nitride (CBN) tools provide solutions to the cutting problems of difficult-to-machine materials.

[0004] Cubic boron nitride (CBN or PCBN) is a synthetic material with a hardness second only to diamond and good high temperature stability (high temperatures are generated when machining hardened ferrous metals and superalloys). CBN tools of different designs are used for continuous or intermittent cutting of hardened ferrous metals, as well as cutting of welded metals and composite metals.

[0005] PCD tools are made by welding PCD materials to the tool body. Generally, PCD materials are produced by sintering diamond particles with a metal-based binder under high temperature and pressure together with the matrix material. The PCD tool tip can be cut by EDM or laser, welded to a carbide or steel matrix, and then sharpened to form a PCD tool. This tool is particularly effective in high-speed machining of non-ferrous metals (such as aluminum) and highly abrasive synthetic materials and plastics. PCD tools are widely used in milling non-ferrous metals, composite materials, plastics and extremely difficult-to-machine super alloys.

[0006] Due to the characteristics of PCD and CBN, it is generally difficult to process them using common grinding methods, especially it is impossible to manufacture a complete spiral blade tool. Instead, multiple patches are spliced ​​into a discontinuous spiral blade.

[0007] For drills and ball cutters, the center edge (also known as tooth gap or transverse edge) is located at the center of tool rotation and plays an important role in cutting. Due to the small rotation radius of the center edge, low linear speed, and difficult to control front and rear angles, its quality is particularly important to tool life and processing.

[0008] The helix angle is also crucial to the cutting performance of the tool. A large amount of literature shows that the cutting performance of tools with a helix angle is better. For tools with superhard material cutting edges, how to obtain superhard material cutting edges and superhard material center cutting edges with a helix angle is a key direction that the tool manufacturing industry continues to explore.

[0009] For example, superhard materials are attached to both sides of the rotation center to form patch tools. This type of tool uses the tilt patch method, which is similar to differential calculus. The arc is divided into several straight lines. When the blade length is short (such as: the blade length does not exceed 10mm), the difference between the blade inclination angle and the helix angle within 15° is small, and a blade inclination angle blade with an approximate helix angle of no more than 15° can be obtained. The problem with this technology is that when the blade length remains unchanged, as the blade inclination angle increases, or when the blade length remains unchanged, as the blade inclination angle increases, the tilt patch method will continue to reduce the tool core thickness until the tool completely loses its rigidity. At the same time, a superhard material patch that forms the blade needs to be installed in a tool groove. Therefore, not only can it not produce a helix or blade inclination angle greater than 15°, but it is also impossible to use superhard materials for the center blade of the tool.

[0010] In order to simultaneously obtain the ideal center blade and spiral main cutting edge made of superhard material, there are also methods such as: material spiral sintering method (Element Six Company, UK) and integral welding ablation method (Iwag Company, Switzerland). In summary, the spiral sintering method is to fill the unsintered superhard material powder into the blank with spiral groove pre-processed, and then sinter the blank and superhard powder at the same time to form a spiral superhard blade blank. The sintered blank is processed to generate a tool with a spiral blade. The main disadvantage of this scheme is that the shape of the tool is limited by the shape of the sintered blank, and the spiral angle parameters cannot be arbitrarily controlled. The integral welding ablation method is to weld the entire cylindrical material composed of superhard material to the tip of the tool as a whole and perform subtractive processing on it to directly obtain the spiral groove and spiral blade. The processing is generally performed by laser. The main disadvantage of this scheme is that it requires a large amount of superhard material, so the preparation cost is also high. Summary of the invention

[0011] One object of the present invention is to provide a blank which is mounted on a substrate to form a tool and can arbitrarily control the helix angle parameters according to the design requirements of the tool.

[0012] Another object of the present invention is to provide a blank that reduces the amount of superhard material used and reduces the manufacturing cost of the tool.

[0013] Another object of the present invention is to provide a blank which is mounted on a substrate to form a cutting tool, and a continuous cutting edge is machined on the same piece of superhard material to facilitate cutting and improve surface quality.

[0014] Another object of the present invention is to provide a cutting tool having a spiral superhard material front cutting face greater than 15°, which is convenient for forming a continuous central cutting edge to facilitate cutting processing and increase the life of the tool.

[0015] The fifth object of the present invention is to provide a chip cutting tool having a continuous superhard material center edge and a superhard material cutting edge having a helix angle greater than 15°, thereby improving machining accuracy and machining efficiency, and increasing the life of the tool.

[0016] Superhard materials such as: cermet, diamond (especially artificial polycrystalline diamond) and cubic boron nitride, or a composite material formed by cemented carbide and one or more of cermet, diamond and cubic boron nitride.

[0017] Cutting tools are tools for cutting materials. In industry, they are also called cutting tools, such as drills, milling cutters and reamers used for hole processing and forming processing.

[0018] A blank is made of superhard material and is used for being fixed on a matrix and can be processed into a cutting edge of a tool. The blank comprises a first side surface and a second side surface, both of which are twisted at a set helix angle.

[0019] A specific implementation manner of a blank is in the shape of a plate, with a thickness greater than 0.3 mm and less than or equal to 4 mm, a length greater than 4 mm and less than or equal to 20 mm, and a width greater than 4 mm and less than or equal to 20 mm.

[0020] Another specific implementation manner of the blank is in the shape of a plate, with a thickness greater than 0.3 mm and less than or equal to 2 mm, a length greater than 4 mm and less than or equal to 16 mm, and a width less than or equal to 4 mm.

[0021] After the blank is fixed to the base, it is processed into cutting edges, such as the main cutting edge and the center cutting edge, which are located on the same blank made of superhard material.

[0022] The blank also includes a third surface, intersecting the first side surface and the second side surface, such as a plane, a curved surface or a folded surface. After the blank is mounted on the base, the third surface is located at the leading end along the direction of tool feeding and is made of the same superhard material.

[0023] The superhard material is cut by a machine tool with a rotary shaft to obtain the green body of the present invention.

[0024] In order to facilitate the processing of the tool, the first helical surface and the second helical surface of the blank are usually arranged in parallel. The helical surface is obtained by twisting the plane, that is, the area of ​​any cross section obtained by cutting at the same angle is equal.

[0025] A cutting tool, comprising:

[0026] The blank is made of a superhard material and is in a plate shape, including a first plate surface and a second plate surface, wherein the first plate surface includes at least a first helical surface, and the first plate surface includes at least a second helical surface;

[0027] The base includes a main body and a longitudinal axis. The main body rotates around the longitudinal axis. One end of the main body is set as a handle that can be installed on a rotating machine, and the other end is set to be processed into a cutting part for performing cutting processing. The cutting part includes a spiral groove body extending radially.

[0028] The blank is assembled with the groove body (eg, welded or bonded), and then a central cutting edge having a front cutting surface and a back cutting surface close to the longitudinal axis and a main cutting edge having a front cutting surface and a back cutting surface are formed on the blank.

[0029] The main cutting edge is formed by a continuous and complete superhard material, having a helical rake face (eg, greater than 15°), while the central cutting edge is formed by the same complete piece of superhard material, extending across the center of rotation.

[0030] Beneficial effects achieved by the technical solution of the present invention:

[0031] Compared with the prior art, the tool provided by the present invention has a main cutting edge formed of a continuous and complete superhard material, and can produce a spiral front cutting edge greater than 15°, which is more conducive to cutting processing, such as: significantly reducing cutting force, improving chip removal, extending tool life and improving surface quality.

[0032] The tool provided by the present invention has a continuous and complete central cutting edge formed of superhard material at the center of rotation. Compared with existing tools, it not only improves the processing accuracy and processing efficiency, but also improves the strength of the center, extends the service life during cutting processing, and significantly improves the overall cutting performance of the tool.

[0033] Compared with the material spiral sintering method, the shape of the tool manufactured by the technical solution of the present invention is not limited by the shape of the sintered blank, and the spiral angle parameters can be arbitrarily controlled according to the design requirements of the tool.

[0034] Compared with the overall welding ablation method, the tool manufactured by the technical solution of the present invention can greatly reduce the use of superhard materials and reduce the manufacturing cost of the tool. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 A schematic diagram of an embodiment of a blank for use in the present invention;

[0036] Figure 2 for Figure 1 A schematic diagram of an angle of the blank shown;

[0037] Figure 3 for Figure 1 A schematic diagram of another angle of the blank shown;

[0038] Figure 4 A schematic diagram of another embodiment of a blank for use in the present invention;

[0039] Figure 5 for Figure 4 A schematic diagram of an angle of the blank shown;

[0040] Figure 6 for Figure 4 A schematic diagram of another angle of the blank shown;

[0041] Figure 7 A schematic diagram of an embodiment of a blank for use in the present invention;

[0042] Figure 8 for Figure 7 A schematic diagram of an angle of the blank shown;

[0043] Fig. 9 for Figure 7 A schematic diagram of another angle of the blank shown;

[0044] Fig.10 A schematic diagram of an embodiment of a base body for a tool of the present invention;

[0045] Fig.11 A schematic diagram of an embodiment of a tool of the present invention;

[0046] Fig.12 A schematic diagram of another embodiment of a tool of the present invention;

[0047] Fig.13 FIG. 2 is a schematic diagram of another embodiment of a tool of the present invention. DETAILED DESCRIPTION

[0048] The technical solution of the present invention is described in detail below with reference to the accompanying drawings. The embodiments of the present invention are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention is described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that the technical solution of the invention can be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the present invention, which should be included in the scope of the claims of the present invention.

[0049] Figure 1 is a schematic diagram of an embodiment of a blank for a tool of the present invention, Figure 2 for Figure 1 A schematic diagram of an angle of the blank is shown. Figure 3 for Figure 1 The schematic diagram of the blank from another angle is shown in FIG. Figure 1 , Figure 2 and Figure 3As shown, a machine tool with a rotary shaft is used to cut the superhard material to obtain a blank 100, which is in a plate shape as a whole, including a first side surface (or plate surface) 110 and a second side surface (or plate surface) 120, both of which are twisted at a set helical angle. Specifically, by changing the clamping method of the superhard material composite sheet, a spiral cutting method of cutting from the side and rotating the composite sheet while cutting is adopted to obtain a blank with a spiral side surface.

[0050] The blank further includes a plane 130, which is in the shape of a plane and intersects the first side surface 110 and the second side surface 120. Similarly, the third plane 130 may also be a curved surface or a folded surface, such as: Figure 4 , Figure 5 , Figure 6 , Figure 7 , Figure 8 and Fig. 9 In this embodiment, the plate body has a thickness greater than 0.3 mm and less than or equal to 4 mm, a length greater than 4 mm and less than or equal to 20 mm, and a width greater than 4 mm and less than or equal to 20 mm.

[0051] Fig.10 Schematic diagram of an embodiment of a base body for a tool of the present invention, as shown in Fig.10 As shown, the base 200 includes a body 210 and a longitudinal axis 220. The body 210 rotates around the longitudinal axis 220. One end of the body 210 is provided as a handle 211 that can be mounted on a rotating machine, and the other end is provided as a cutting portion 212 for performing cutting processing. The cutting portion 212 includes a spiral groove 230 extending radially. Figure 1 , Figure 2 , Figure 3 and Fig.10 ,like Fig.11 As shown, the blank 100 and the slot body 230 are assembled and fixed by welding or bonding to obtain a blank for making a tool, and then a central cutting edge 310 with a front cutting face and a back cutting face close to the longitudinal axis and a main cutting edge 320 with a front cutting face and a back cutting face are formed on the blank 100. The main cutting edge 320 is formed of a continuous and complete superhard material and has a spiral front cutting face (e.g., greater than 15°), and the central cutting edge 310 is formed of the same complete superhard material and spans the center of rotation.

[0052] Fig.12 is a schematic diagram of another embodiment of the tool of the present invention, Fig.13 FIG. 1 is a schematic diagram of another embodiment of the tool of the present invention. Figure 4 , Figure 5 , Figure 6 , Figure 7 , Figure 8 and Fig. 9 As shown, Fig.12 and Fig.13 As shown, by changing the shape of the third surface of the blank 100, such as but not limited to a curved surface or a folded surface, various types of tools can be processed as required, such as a ball-end tool.

Claims

1. A green body made of superhard material, characterized in that Used to be fixed on a base body and can be processed into a cutting edge portion of a tool, comprising a first side surface and a second side surface, both of which are twisted at a set helix angle; The blade portion comprises a main cutting edge and a central cutting edge, which are located on a blank made of the same superhard material.

2. The blank according to claim 1, characterized in that It also includes a third surface, which intersects with the first side surface and the second side surface, is located at the leading end along the direction of tool feeding, and is made of the same superhard material.

3. The tool according to claim 2, characterized in that The third surface is a plane, a curved surface or a folded surface.

4. The tool according to claim 1, characterized in that The blank is in a plate shape, with a thickness greater than 0.3 mm and less than or equal to 4 mm, a length greater than 4 mm and less than or equal to 20 mm, and a width greater than 4 mm and less than or equal to 20 mm.

5. The tool according to claim 1, characterized in that The blank is in a plate shape, with a thickness greater than 0.3 mm and less than or equal to 2 mm, a length greater than 4 mm and less than or equal to 16 mm, and a width less than or equal to 4 mm.

6. A cutting tool, characterized in that include: The blank is made of a superhard material and is in a plate shape, including a first plate surface and a second plate surface, wherein the first plate surface includes at least a first helical surface, and the first plate surface includes at least a second helical surface; The base body includes a main body and a longitudinal axis, the main body rotates around the longitudinal axis, one end of the main body is configured as a handle that can be mounted on a rotating machine, and the other end is configured as a cutting part for performing a cutting process, the cutting part includes a spiral groove body extending radially; Assembling the blank and the groove body, and then machining the blank to form a central cutting edge having a rake face and a relief face close to the longitudinal axis, and a main cutting edge having a rake face and a relief face; The main cutting edge is made of a continuous and complete superhard material and has a spiral rake face, and the central cutting edge is made of the same complete superhard material and spans the center of rotation.

7. The cutting tool according to claim 6, characterized in that The blank is obtained by cutting superhard material using a machine tool with a rotary shaft.

8. The cutting tool according to claim 6, characterized in that The first helical surface and the second helical surface of the blank are usually arranged in parallel, and the helical surface is obtained by twisting a plane.

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