A variable-depth-of-cut tungsten steel round nose milling cutter

Abstract

The utility model provides a kind of tungsten steel round nose milling cutter of variable flute depth chip removal, it is related to machining tool technical field, including: tool body, the one end of tool body is provided with cutting part, the cutting part includes several chip flutes, several chip flutes spiral extension along the axis of tool body, several chip flutes are all formed with side cutting edge between, several side cutting edges are all connected by circular arc cutting edge between, the depth of groove bottom of chip flute gradually becomes shallow from the direction of one end of tool body to the other end of tool body;The utility model, by the structure that chip flute is designed to gradually become shallow in depth from the direction of one end of tool body to the other end, under the action of centrifugal force and flushing of cutting fluid in milling process, chip can be naturally guided along groove bottom from deep to shallow, thereby smoothly discharged from tool exterior, effectively avoid chip retention and blockage in groove, effectively improve the practicability of milling cutter.

Description

Technical Field

[0001] This utility model relates to the field of machining tool technology, and in particular to a tungsten carbide round nose end mill with variable groove depth chip removal. Background Technology

[0002] Round nose end mills are also known as bullnose end mills because the tip of the end mill has a rounded corner. They also have the side milling capability of end mills and the contouring capability of ball end mills. They are widely used in mold making, aerospace component manufacturing and other fields. Tungsten carbide round nose end mills have become the mainstream choice for machining high-hardness materials due to their high hardness and high wear resistance.

[0003] However, in the existing technology, existing tungsten carbide round nose end mills generally have the problem of poor chip removal when machining sticky materials such as stainless steel, high-temperature alloys, and titanium alloys. The chips generated during machining tend to stick to the chip groove, causing chip groove blockage. This requires operators to frequently retract the tool to clear the chips, which reduces machining efficiency. If the chips are not cleaned in time, the blocked chips will generate severe friction with the tool surface and the machined surface, causing rapid wear of the tool's rake and flank faces and significantly shortening the tool life. Utility Model Content

[0004] The purpose of this invention is to overcome the shortcomings of the existing technology and provide a tungsten carbide round nose end mill with variable groove depth and chip removal.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: a tungsten carbide round nose end mill with variable groove depth chip removal, comprising: a tool body, a cutting section provided at one end of the tool body, the cutting section including a plurality of chip grooves, the plurality of chip grooves extending spirally along the axis of the tool body, a side cutting edge formed between the plurality of chip grooves, the plurality of side cutting edges being connected by a circular arc cutting edge, and the groove bottom depth of the chip grooves gradually decreasing from one end of the tool body to the other end of the tool body.

[0006] In a preferred embodiment, the bottom of the chip groove is a shallow curve that smoothly transitions from one end of the tool body to the other end of the tool body, and the shallow curve of the chip groove is designed as an arc curve.

[0007] In a preferred embodiment, the cutting edge of the side cutting edge is a helix with a constant helix angle, the helix angle of the side cutting edge is in the range of 35 degrees to 45 degrees, and one end of the tool body is provided with end teeth.

[0008] In a preferred embodiment, chip breaking grooves are provided on the inner side of each of the chip receiving grooves, and the chip breaking grooves are arranged in a circumferential array.

[0009] In a preferred embodiment, the tool body is made of tungsten-based cemented carbide, and the radius of the arc cutting edge ranges from 0.5 mm to 5 mm.

[0010] In a preferred embodiment, the cutting edge of the cutting part is coated with a wear-resistant coating, which is a TiAlN coating.

[0011] Compared with the prior art, the advantages and positive effects of this utility model are as follows:

[0012] 1. This utility model designs the chip groove as a structure in which the depth gradually decreases from one end of the tool body to the other. During the milling process, the chips can be naturally guided along the bottom of the groove from deep to shallow under the action of centrifugal force and cutting fluid, so as to be smoothly discharged from the outside of the tool. This effectively avoids the chips from being stuck and blocked in the groove, and effectively improves the practicality of the milling cutter.

[0013] 2. The deepest chip groove is located at one end of the tool body, providing the largest chip space to accommodate the large amount of chips generated in the area with the heaviest cutting load. As it extends towards the other end of the tool body, the groove depth becomes shallower and the core thickness of the tool body gradually increases, ensuring the overall strength and rigidity of the tool body, effectively resisting cutting torque and radial force, and avoiding vibration and deformation of the tool body. Attached Figure Description

[0014] Figure 1 A schematic diagram of the overall structure of a tungsten carbide round nose end mill with variable groove depth and chip removal provided by this utility model.

[0015] Figure 2 A side view of the overall structure of a tungsten carbide round nose end mill with variable groove depth and chip removal provided by this utility model.

[0016] Figure 3 A cross-sectional view of the tool body of a tungsten carbide round nose end mill with variable groove depth and chip removal provided by this utility model.

[0017] Figure 4 A bottom view of the overall structure of a tungsten carbide round nose end mill with variable groove depth and chip removal provided by this utility model.

[0018] Legend:

[0019] 11. Tool body;

[0020] 2. Cutting section; 21. Chip groove; 22. Side cutting edge; 23. Circular arc cutting edge; 24. End tooth; 25. Chip breaker. Detailed Implementation

[0021] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0022] Example 1

[0023] like Figure 1-4 As shown, this utility model provides a technical solution: a tungsten carbide round nose end mill with variable groove depth chip removal, comprising: a tool body 11, a cutting part 2 provided at one end of the tool body 11, the cutting part 2 including a plurality of chip grooves 21, the plurality of chip grooves 21 extending spirally along the axis of the tool body 11, a side cutting edge 22 formed between the plurality of chip grooves 21, the plurality of side cutting edges 22 being connected by a circular arc cutting edge 23, the groove bottom depth of the chip grooves 21 gradually decreasing from one end of the tool body 11 to the other end of the tool body 11, the groove bottom of the chip grooves 21 being a shallowing curve smoothly transitioning from one end of the tool body 11 to the other end of the tool body 11, the shallowing curve of the chip grooves 21 being a circular arc curve design, the cutting edge line of the side cutting edge 22 being a helical line with a constant helix angle, the helix angle angle of the side cutting edge 22 being in the range of 35 degrees to 45 degrees, and an end tooth 24 provided at one end of the tool body 11.

[0024] In this embodiment, the bottom shape design of the chip groove 21 is such that... Figure 3 and Figure 4 As shown, the bottom of the chip groove 21 is not of uniform depth, but rather gradually becomes shallower smoothly from one end of the tool body 11 towards the other end. Specifically, it is characterized by... Figures 4 to 3Regarding the proportion of the chip groove 21, the depth of the chip groove 21 at one end of the tool body 11 is greater than the depth of the chip groove 21 at the other end near the tool body 11. The shallowing curve at the bottom of the chip groove 21 is an arc curve. During milling, the cutting force is transmitted to the bottom of the chip groove 21 through the side cutting edge 22 and the arc cutting edge 23, and then to the core of the tool body 11. The shape of the curve at the bottom of the chip groove 21 directly determines the degree of stress concentration. The arc curve has a constant radius of curvature and is the smoothest and most continuous transition form among all connection methods. This arc curve can effectively achieve a smooth transition, avoiding sharp inflection points or... The abrupt change in curvature, through the arc curve, can evenly distribute the stress generated by cutting throughout the entire area, significantly improving the fatigue strength and overall toughness of the tool body 11, thereby greatly extending the service life of the tool body 11. By setting the cutting edge of the side cutting edge 22 to be a helix with a constant helix angle, the constant helix angle can effectively keep the contact point between the tool body 11 and the workpiece changing smoothly and continuously along the axis, rather than suddenly cutting in or out. This smooth transition can greatly reduce the impact and vibration during the cutting process. On the one hand, it can make the machining process quieter, and on the other hand, it can effectively avoid the occurrence of vibration marks on the workpiece surface, thereby obtaining a smoother surface and ensuring the production quality of the machined parts.

[0025] Example 2

[0026] like Figure 1-4 As shown, chip breaking grooves 25 are provided on the inner side of several chip grooves 21. The chip breaking grooves 25 are arranged in a circumferential array. The overall material of the tool body 11 is tungsten-based cemented carbide. The radius of the arc cutting edge 23 is between 0.5 mm and 5 mm. The cutting edge of the cutting part 2 is coated with a wear-resistant coating. The wear-resistant coating of the cutting part 2 is a TiAlN coating.

[0027] In this embodiment, the chip breaker groove 25 effectively controls the shape and flow direction of the chips. A curling stress is applied to the chips during their formation. When this curling stress exceeds the strength limit of the chip material itself, the chips break, thus curling and breaking the continuous long chips into easily manageable small segments. This effectively ensures timely chip breakage, preventing long chips from entangled in the milling cutter, thereby protecting the machined surface and extending the milling cutter's service life. The tool body 11 is made of tungsten-based cemented carbide, which has extremely high elastic modulus and bending strength. This ensures that even when the groove depth is greatest and the core thickness is thinnest at one end of the tool body 11, the tool body... The body 11 still possesses sufficient rigidity to resist cutting forces, preventing vibration or even breakage of the tool body 11 during cutting. If other materials such as high-speed steel were used, they would likely fail due to insufficient strength under this structure. Therefore, tungsten steel effectively provides material protection for the variable groove depth structure design. By coating the cutting edge of the cutting part 2 with a TiAlN coating, which has extremely high hardness, it can effectively resist abrasive wear and keep the cutting edge of the milling cutter sharp under high-speed cutting conditions. Moreover, the TiAlN coating has a low coefficient of friction, which can reduce cutting forces and cutting heat, thereby obtaining better machining surface quality.

[0028] Working principle:

[0029] like Figure 1-4 As shown, during milling, the generated chips enter the chip groove 21. Due to the design of the chip groove 21, which is shallower from the end to the tail, it provides an inclined slide for the chips. Under the combined action of the centrifugal force generated by the high-speed rotation of the tool body 11 and the flushing effect of the cutting fluid, the chips will be quickly thrown out of the chip groove 21 along the slide, without accumulating inside the chip groove 21. At the same time, the shallow depth of the chip groove 21 at the tail ensures that the tool body 11 has a sufficiently thick core, ensuring the strength and stability of the tool body 11.

[0030] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments for application in other fields. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present utility model without departing from the technical solution of the present utility model shall still fall within the protection scope of the technical solution of the present utility model.

Claims

1. A tungsten carbide round nose end mill with variable groove depth and chip removal, characterized in that, include: The tool body (11) has a cutting part (2) at one end. The cutting part (2) includes a plurality of chip grooves (21). The plurality of chip grooves (21) extend spirally along the axis of the tool body (11). A side cutting edge (22) is formed between the plurality of chip grooves (21). The plurality of side cutting edges (22) are connected by a circular arc cutting edge (23). The depth of the bottom of the chip groove (21) gradually decreases from one end of the tool body (11) to the other end of the tool body (11).

2. The tungsten carbide round nose end mill with variable groove depth chip removal according to claim 1, characterized in that: The bottom of the chip groove (21) is a shallow curve that smoothly transitions from one end of the tool body (11) to the other end of the tool body (11), and the shallow curve of the chip groove (21) is designed as an arc curve.

3. A tungsten carbide round nose end mill with variable groove depth and chip removal according to claim 1, characterized in that: The cutting edge of the side cutting edge (22) is a helix with a constant helix angle. The helix angle of the cutting edge of the side cutting edge (22) ranges from 35 degrees to 45 degrees. One end of the tool body (11) is provided with an end tooth (24).

4. A tungsten carbide round nose end mill with variable groove depth and chip removal according to claim 1, characterized in that: The inner side of each of the chip-receiving grooves (21) is provided with a chip-breaking groove (25), and the chip-breaking grooves (25) are arranged in a circular array.

5. A tungsten carbide round nose end mill with variable groove depth and chip removal according to claim 1, characterized in that: The tool body (11) is made of tungsten-based cemented carbide, and the radius of the arc cutting edge (23) is between 0.5 mm and 5 mm.

6. A tungsten carbide round nose end mill with variable groove depth and chip removal according to claim 1, characterized in that: The cutting edge of the cutting part (2) is coated with a wear-resistant coating, which is a TiAlN coating.

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