A drum cutter

Abstract

The present invention discloses a drum-shaped milling cutter, which includes a drum-shaped cutting part, a chip pocket and a shank. The chip pocket extends from the drum-shaped cutting part to the shank. The drum-shaped cutting part includes a rotary outer peripheral surface formed by rotating its generatrix S around the rotation center axis of the shank. The surface of the chip pocket facing the cutting rotation direction is the rake face. The rake face intersects with the rotary outer peripheral surface to form a cutting edge. The generatrix S satisfies the polar coordinate equation ρ = a×cos(b×θ), where the constant a≠0 and the constant b is a positive integer. The drum-shaped milling cutter of the present invention has the advantages of being able to simultaneously realize roughing and finishing of blades, high processing efficiency, and low manufacturing difficulty, etc.

Description

Technical Field

[0001] The present invention mainly relates to the field of metal cutting, and particularly relates to a drum-shaped milling cutter. Background Art

[0002] Due to high cutting efficiency, drum-shaped milling cutters are widely used in the processing of blades and integral impellers. However, the drum-shaped milling cutters in the prior art usually have problems such as no cutting edge at the bottom, inability to complete roughing and finishing of blades in one go, low processing efficiency, complex edge structure, and high manufacturing difficulty.

[0003] For example, Chinese Patent Document CN1413790A discloses a drum-cone tool and a method for machining a complex-curved centrifugal impeller. The cutting part of the tool is a rotary surface, and the generatrix is an arc with a radius of R. There is no cutting edge at the bottom of the tool; Chinese Patent Document CN107243668A discloses a drum-shaped alloy milling cutter. The side surface of the cutter body is an arc-shaped milling edge, and the arc-shaped milling edge is a rotary surface. The generatrix is an arc with a radius of R, and the center of the arc is located in a plane passing through the midpoint of the arc and perpendicular to the axis of the tool shank. The main defect of the drum-shaped milling cutters with the above two structures is that there is no cutting edge at the bottom, and it is impossible to complete roughing and finishing of blades in one go, resulting in low processing efficiency.

[0004] Chinese Patent Document CN110695426A discloses an efficient drum-shaped profiling end mill. Its cutting part is divided into a circumferential cutting edge and a ball-end cutting edge. The contour of its circumferential cutting edge consists of two symmetric arcs, and the bottom cutting edge is a ball-end cutting edge; Chinese Patent Document CN114888342A discloses a method for machining integral blisk blades with a drum-shaped cutter. The cutting edge of the drum-shaped cutter consists of a tip with a radius of curvature of R1 and a side edge with a radius of curvature of R2. Although the above two types of drum-shaped milling cutters can complete roughing and finishing of blades in one go, their edge structures are complex, composed of two or more arc edges, with high manufacturing difficulty, and the radius of curvature of each cutting point on the arc edge is fixed, making it easy to occur interference phenomena during the blade milling process. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a drum-shaped milling cutter that can simultaneously achieve roughing and finishing of blades, has high processing efficiency, and low manufacturing difficulty.

[0006] To solve the above technical problems, the present invention adopts the following technical solutions:

[0007] A drum-shaped milling cutter includes a drum-shaped cutting part, a chip flute, and a shank. The chip flute extends from the drum-shaped cutting part to the shank. The drum-shaped cutting part includes a rotary outer peripheral surface formed by rotating its generatrix S around the rotation center axis of the shank. The surface of the chip flue facing the cutting rotation direction is the rake face. The rake face intersects with the rotary outer peripheral surface to form a cutting edge. The generatrix S satisfies the polar coordinate equation ρ = a×cos(b×θ), where the constant a≠0 and the constant b is a positive integer. The generatrix S extends to the rotation center axis, and the chip flue extends to the rotation center axis.

[0008] As a further improvement of the above technical solution:

[0009] 2≤b≤100.

[0010] In the radial section of the drum-shaped milling cutter, the distance between the cutting edge and the rotation center axis gradually increases in the direction from the drum-shaped cutting part to the shank.

[0011] Compared with the prior art, the advantages of the present invention are as follows:

[0012] The drum-shaped milling cutter of the present invention is formed only by rotating a single generatrix S, with a simple structure, stable and reliable, and reducing the manufacturing difficulty of the drum-shaped milling cutter; the generatrix S extends to the rotation center axis, and the chip flue extends to the rotation center axis, that is, there is still a cutting edge at the rotation center axis of the drum-shaped milling cutter. This part of the cutting edge can be used for fine milling of the blade, enabling rough and fine machining of the blade to be completed in one clamping, reducing the tool change frequency, improving production efficiency, and reducing processing costs; the generatrix S satisfies the polar coordinate equation ρ = a×cos(b×θ), and the edge curvature radius of the cutting edge changes continuously, which can effectively avoid interference and undercut phenomena during milling of the blade, improving the machining quality. Description of the Drawings

[0013] Figure 1 is a schematic structural diagram of the drum-shaped milling cutter of the present invention.

[0014] Figure 2 is a schematic diagram of the generatrix of the drum-shaped cutting part of the drum-shaped milling cutter of the present invention in polar coordinates.

[0015] The reference numerals in the figure represent:

[0016] 1, drum-shaped cutting part; 2, chip flue; 3, shank; 4, cutting edge; 5, rotation center axis. Detailed Embodiments

[0017] The present invention will be further described in detail below with reference to the accompanying drawings of the specification and specific embodiments.

[0018] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "horizontal", "inner", "outer", "top", "bottom", etc. indicating orientation or positional relationship are based on the orientation or positional relationship shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present invention.

[0019] Figures 1 to 2 An embodiment of the drum-shaped milling cutter of the present invention is shown. The drum-shaped milling cutter of this embodiment includes a drum-shaped cutting part 1, a chip flute 2 and a shank part 3. The chip flute 2 extends from the drum-shaped cutting part 1 to the shank part 3. The drum-shaped cutting part 1 includes a rotary outer peripheral surface formed by rotating its generatrix S around the rotation center axis 5 of the shank part 3. The surface of the chip flute 2 facing the cutting rotation direction is the rake face. The rake face intersects with the rotary outer peripheral surface to form a cutting edge 4. The generatrix S satisfies the polar coordinate equation ρ = a×cos(b×θ), where the constant a≠0 and the constant b is a positive integer. The generatrix S extends to the rotation center axis 5, and the chip flute 2 extends to the rotation center axis 5. The drum-shaped milling cutter of this embodiment is only formed by rotating one generatrix S, with a simple structure, stable and reliable, and reducing the manufacturing difficulty of the drum-shaped milling cutter; the generatrix S extends to the rotation center axis 5, and the chip flute 2 extends to the rotation center axis 5, that is, there is still a cutting edge 4 at the rotation center axis 5 of the drum-shaped milling cutter. This part of the cutting edge 4 can be used for the finish milling of the blade, and it can realize the rough and finish machining of the blade in one clamping, reducing the tool change frequency, improving the production efficiency and reducing the processing cost; the generatrix S satisfies the polar coordinate equation ρ = a×cos(b×θ), and the edge curvature radius of the cutting edge 4 changes continuously, which can effectively avoid interference and overcut phenomena when milling the blade, and improve the machining quality.

[0020] It should satisfy: 2≤b≤100. In this embodiment, b = 3, and at this time it is called a 3-leaf rose curve; if b = 5, it is a 5-leaf rose curve, and if b = 7, it is a 7-leaf rose curve.

[0021] The value of a is related to the size of the drum-shaped milling cutter. The larger the size of the drum-shaped milling cutter, the larger a is. The specific value needs to be calculated according to the specific size of the drum-shaped milling cutter. In this embodiment, a = 150.

[0022] In this embodiment, in the radial section of the drum-shaped milling cutter, the distance between the cutting edge 4 and the rotation center axis 4 gradually increases in the direction from the drum-shaped cutting part 1 to the shank part 3.

[0023] Although the present invention has been disclosed above in preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make many possible changes and modifications to the technical solution of the present invention, or modify it into equivalent embodiments with equivalent changes, without departing from the scope of the technical solution of the present invention. Therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the scope of protection of the technical solution of the present invention.

Claims

1. A drum-shaped milling cutter, comprising a drum-shaped cutting part (1), a chip flute (2) and a shank (3), wherein the chip flute (2) extends from the drum-shaped cutting part (1) to the shank (3), and the drum-shaped cutting part (1) comprises a rotary outer peripheral surface formed by rotating its generatrix S around the rotation center axis (5) of the shank (3), characterized in that: The face of the chip pocket (2) facing the cutting rotation direction is the rake face. The rake face intersects with the circumferential outer surface to form a cutting edge (4). The generatrix S satisfies the polar coordinate equation ρ = a×cos(b×θ), where the pole of the polar coordinate is the intersection point of the tool tip and the rotation center axis (5), the constant a ≠ 0, the constant b is a positive integer, the generatrix S extends to the rotation center axis (5), and the chip pocket (2) extends to the rotation center axis (5).

2. The drum cutter according to claim 1, wherein: 2≤b≤100。 3. The drum cutter according to claim 1 or 2, characterized in that: In the radial section of the drum cutter, the distance between the cutting edge (4) and the rotation center axis (5) gradually increases in the direction from the drum cutting part (1) to the shank part (3).

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