A spherical milling cutter

Abstract

The present invention relates to the field of mechanical processing tools, and in particular to a spherical milling cutter, comprising a shank, a cylindrical cutting edge and a ball-end cutting edge connected in sequence, the diameter of the cylindrical cutting edge being the same as the diameter of the ball-end cutting edge, the surface of the ball-end cutting edge and the surface of the cylindrical cutting edge being evenly distributed with a plurality of spiral grooves along the circumference, a spiral tooth edge being formed between adjacent spiral grooves, the back angle of the spiral tooth edge being 3° to 5°, the front angle being ‑1° to ‑3°; and a groove bottom circular arc being provided at the bottom of the spiral groove. The present invention greatly enhances the strength of the cutting edge by designing the front angle of the spiral edge to be a negative front angle, and converts the front angle of the spiral edge to a circular arc at the root of the tooth groove, improves the impact resistance of the cutting edge during high-speed milling, reduces the probability and degree of tool damage during processing, effectively prolongs the life of the tool, has a simple structure, is easy to use, and better solves the problem of efficient processing of the edge of difficult-to-process high-temperature alloy materials.

Description

Technical Field

[0001] The invention relates to the field of mechanical processing tools, in particular to a spherical milling cutter. Background Art

[0002] After turning, milling, broaching and other mechanical processing, high-temperature alloy workpieces will form flash, burrs, etc. on the edges of external corners, holes and grooves, which generally require deburring or rounding and chamfering. Traditional processing tools such as polishing knives, rotary files and other bench tools must be handled manually, which has problems such as large dust, high safety risks (high-speed rotation of tools), and low surface uniformity; although the efficiency of special forming chamfering and rounding cutters is acceptable, they are not versatile enough and are only suitable for rounding and chamfering the edges of planes and simple surfaces, but are powerless for edges with special-shaped curves; although ordinary carbide ball-end milling cutters have processing versatility, when processing high-temperature alloys, their linear speed and feed speed are low, generally not exceeding 25m / min and 150mm / min, and the processing efficiency cannot meet the requirements. Summary of the invention

[0003] In view of the problems existing in the prior art, the present invention provides a spherical milling cutter.

[0004] The present invention is achieved through the following technical solutions:

[0005] A spherical milling cutter comprises a tool handle, a cylindrical cutting edge and a ball-end cutting edge connected in sequence, wherein the diameter of the cylindrical cutting edge is the same as that of the ball-end cutting edge, a plurality of spiral grooves are evenly distributed along the circumference on the surfaces of the ball-end cutting edge and the cylindrical cutting edge, and a spiral tooth edge is formed between adjacent spiral grooves, wherein the back angle of the spiral tooth edge is 3° to 5°, and the front angle is -1° to -3°; and a groove bottom arc is provided at the bottom of the spiral groove.

[0006] Preferably, the helix angle of the helical tooth edge is 60° to 80°.

[0007] Preferably, the radial depth of the spiral groove is 0.15 mm to 0.25 mm.

[0008] Preferably, the radius of the arc at the bottom of the groove is 0.1 mm to 0.15 mm.

[0009] Preferably, the knife handle is cylindrical.

[0010] Preferably, the diameter of the tool handle is 1 to 2 times the diameter of the ball-end cutting edge.

[0011] Preferably, the cylindricity of the tool handle is 0.005 mm, and the coaxiality of the outer diameter of the spiral blade relative to the tool handle is less than 0.05 mm.

[0012] Preferably, a transition section is provided between the tool handle and the cylindrical cutting edge, the transition section comprising a bevel section and a transition arc, one end of the transition arc is connected to the cylindrical cutting edge, and the other end is connected to the lower end of the bevel section, and the higher end of the bevel section is connected to the tool handle.

[0013] Preferably, the angle between the bevel segment and the axis of the cylindrical cutting edge is 25° to 30°.

[0014] Preferably, the radius of the transition arc is greater than or equal to 0.2 mm.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] The spherical milling cutter of the present invention can be used as a high-speed milling tool for removing burrs, chamfering and rounding the edges of high-temperature alloy parts on a high-speed CNC machine tool, and can replace a large number of existing benchwork operations, reduce the labor intensity of workers, improve the degree of automation, and improve the edge processing quality and processing efficiency of parts.

[0017] By designing the spiral blade rake angle as a negative rake angle and converting it to a circular arc at the root of the tooth groove, the strength of the cutting edge is greatly enhanced, and the impact resistance of the cutting edge during high-speed milling is improved, the probability and degree of tool breakage during processing are reduced, and the life of the tool is effectively extended. When milling the edges of nickel-based high-temperature alloy parts, the processing line speed is as high as 100m / min, the feed speed is 1000m / min, and the life is as long as 2h, which is 8 to 10 times more efficient than ordinary milling cutters.

[0018] Furthermore, since the chips are thinner during high-speed milling, the reduction of the chip groove has less impact on the processing, so the depth of the spiral groove is limited, which helps to improve the strength of the cutting edge.

[0019] Furthermore, the diameter of the tool holder is 1 to 2 times the diameter of the ball head cutting edge, which is beneficial to enhancing the rigidity of the tool and reducing process vibration during high-speed milling.

[0020] Furthermore, the cylindricity of the tool holder is 0.005 mm in order to meet the clamping requirements of high-speed milling machines.

[0021] Furthermore, the transition section is intended to reduce stress concentration at the junction of the cylindrical cutting edge and the tool holder. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A schematic diagram of a spherical milling cutter according to the present invention;

[0023] Figure 2 The figure is a cross-sectional view of a spherical milling cutter according to the present invention.

[0024] In the figure, 1, tool handle; 201, bevel section; 202, transition arc; 301, cylindrical cutting edge; 302, ball head cutting edge. DETAILED DESCRIPTION

[0025] The present invention is further described in detail below in conjunction with specific embodiments, which are intended to explain the present invention rather than to limit it.

[0026] The present invention discloses a spherical milling cutter, referring to Figure 1 , 2 The tool holder 1 includes a tool holder 1, a cylindrical cutting edge 301 and a ball-end cutting edge 302 which are connected in sequence and are integrally formed. The diameter of the cylindrical cutting edge 301 is the same as that of the ball-end cutting edge 302. The tool holder 1 is cylindrical, and the cylindricality of the tool holder 1 is 0.005 mm. The diameter of the tool holder 1 is 1 to 2 times the diameter of the ball-end cutting edge 302.

[0027] Several spiral grooves are evenly distributed along the circumference on the surface of the ball-end cutting edge 302 and the surface of the cylindrical cutting edge 301. The radial depth of the spiral groove is 0.15mm-0.25mm. A groove bottom arc is provided at the bottom of the spiral groove. The radius of the groove bottom arc is 0.1mm-0.15mm.

[0028] A spiral tooth edge is formed between adjacent spiral grooves, the helix angle of the spiral tooth edge is 60° to 80°, the back angle of the spiral tooth edge is 3° to 5°, and the front angle is -1° to -3°.

[0029] The coaxiality of the outer diameter of the spiral tooth edge relative to the tool handle 1 is less than 0.05 mm.

[0030] A transition section is provided between the tool handle 1 and the cylindrical cutting edge 301 , and the transition section includes a bevel section 201 and a transition arc 202 , one end of the transition arc 202 is connected to the cylindrical cutting edge 301 , and the other end is connected to the lower end of the bevel section 201 , and the higher end of the bevel section 201 is connected to the tool handle 1 .

[0031] The angle between the bevel section 201 and the axis of the cylindrical cutting edge 301 is 25° to 30°.

[0032] The radius r1 of the transition arc 202 is greater than or equal to 0.2 mm.

[0033] The spherical milling cutter is made of cemented carbide to ensure that the spherical milling cutter has high wear resistance.

[0034] Example 1

[0035] The tool consists of a tool handle 11, a transition section 201, a transfer arc 202, a cylindrical cutting edge 301, and a ball-end cutting edge 302, and is made of K44 cemented carbide.

[0036] Diameter of ball-end cutting edge 302 Less than 2 times the minimum curvature radius of the edge surface to be processed. For example, if the minimum curvature radius of the edge surface to be processed is R=2, then the diameter of the ball-end cutting edge 302 can be

[0037] Diameter of handle 1 Should be the diameter of the ball end cutting edge 302 1 to 2 times of

[0038] The helix angle a is selected as 70°, the transition bevel angle b is selected as 27°, the radius r1 of the transition arc 202 is selected as 0.2mm, the number of teeth is 12, the front angle γ of the spiral groove is selected as -2°, the back angle is selected as 4°, the radius r2 of the groove bottom arc is selected as 0.2mm, the spiral groove depth is selected as 0.2mm, and the number of teeth is selected as 12.

[0039] Using the spherical milling cutter of Example 1, the processing time of a single part is 1.5 hours to 2 hours, while the processing time of a single part of an existing conventional milling cutter is 7 hours to 8 hours, which significantly improves the processing efficiency of the part. Secondly, conventional milling cutters require multiple tools for processing, while the present invention only uses one spherical milling cutter to complete the processing of the part.

[0040] The above description is only a preferred embodiment of the present invention and is not intended to impose any limitation on the technical solution of the present invention. Those skilled in the art should understand that, without departing from the spirit and principles of the present invention, the technical solution can also be subjected to several simple modifications and substitutions, and these modifications and substitutions are also within the scope of protection covered by the claims.

Claims

1. A spherical milling cutter, characterized in that: The tool comprises a tool handle (1), a cylindrical cutting edge (301) and a ball-end cutting edge (302) connected in sequence, wherein the diameter of the cylindrical cutting edge (301) is the same as the diameter of the ball-end cutting edge (302), a plurality of spiral grooves are evenly distributed along the circumference on the surfaces of the ball-end cutting edge (302) and the cylindrical cutting edge (301), and spiral tooth edges are formed between adjacent spiral grooves, wherein the back angle of the spiral tooth edges is 3° to 5° and the front angle is -1° to -3°; and a groove bottom arc is provided at the bottom of the spiral groove; The helix angle of the helical tooth blade is 60° to 80°; The radial depth of the spiral groove is 0.15 mm to 0.25 mm; The radius of the arc at the bottom of the groove is 0.1 mm to 0.15 mm; A transition section is provided between the tool handle (1) and the cylindrical cutting edge (301), the transition section comprising a bevel section (201) and a transition arc (202), one end of the transition arc (202) being connected to the cylindrical cutting edge (301), and the other end being connected to the lower end of the bevel section (201), and the higher end of the bevel section (201) being connected to the tool handle (1); the radius of the transition arc (202) being greater than or equal to 0.2 mm; the angle between the bevel section (201) and the axis of the cylindrical cutting edge (301) being 25° to 30°; The spherical milling cutter is made of hard alloy.

2. The spherical milling cutter according to claim 1, characterized in that: The knife handle (1) is cylindrical.

3. The spherical milling cutter according to claim 1, characterized in that: The diameter of the tool handle (1) is 1 to 2 times the diameter of the ball head cutting edge.

4. The spherical milling cutter according to claim 3, characterized in that: The cylindricity of the tool handle (1) is 0.005 mm, and the coaxiality of the outer diameter of the spiral tooth blade relative to the tool handle (1) is less than 0.05 mm.

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