CN114535677A - Variable-spiral unequal-pitch end mill with surface microtexture - Google Patents

Abstract

The invention discloses a variable helical unequal pitch end mill with surface micro-texture. The technical solution of the end mill is as follows: a shank part and a milling cutter head are provided, and a plurality of milling edges are arranged on the milling cutter head, including four One peripheral milling edge and four bottom milling edges, among which the peripheral milling edge on the cylindrical surface of the milling cutter adopts a variable helical structure, and a variable pitch structure is adopted between the adjacent two bottom milling edges, and a chip flute is arranged between each milling edge. , There are multiple rows of circular micro-textures arranged in a fan shape on the end face of the end mill. The milling cutter is provided with a plurality of cooling channels, the upper ends of the cooling channels are communicated with the liquid inlet holes, the bottom of the milling cutter head is provided with an outlet communicated with the cooling channel, and a filter screen is fixed inside the outlet. The invention can effectively reduce the vibration of the tool during the milling process, enhance the lubricating effect of the coolant, reduce the friction between the tool and the workpiece, reduce the milling force during the processing, and prevent the granular impurities generated during the processing from blocking the cooling holes, extending tool life.

Description

A variable helical unequal pitch end mill with surface microtexture

technical field

The invention relates to the field of milling tool design, in particular to a variable helix unequal pitch end mill with surface micro-texture.

Background technique

Milling is one of the main manufacturing methods for material removal, and is widely used in the processing of various complex curved surfaces and metal parts. For conventional standard end mills, the pitch between the teeth is equal, the helix angle is the same, the milling amount is the same, and the milling can be highly concentrated. Therefore, in the milling process, it is easy to excite the vibration of the milling system, which seriously affects the machining accuracy and the surface quality of the workpiece, aggravates tool wear, and reduces the service life of the tool. Variable helix unequal pitch milling cutters are a cost-effective method to reduce milling vibration. For variable helical unequal pitch milling cutters, the milling time intervals of the peripheral edges in the rotation direction of the end mill are not equal, resulting in different time intervals for each peripheral edge to cut into the workpiece. The effective length of the milling cutter and the feed per tooth of the milling cutter are not equal, so it can destroy the distribution of the exciting force in the frequency domain, and can make the milling frequency domain relatively dispersed during the processing, reduce chatter, and also can Reduce the milling force during the milling process and improve the surface quality and machining accuracy.

In the milling process, although the second end face relief angle can reduce the friction between the end face and the workpiece, the end face is a smooth surface, and the smooth surface is not necessarily wear-resistant, and the more wear-resistant surface often has a shape that is not smooth. . According to research, surface texture can effectively reduce the friction force, that is, a micro-texture with a certain regular arrangement is prepared on the surface of the friction pair, and this method can significantly improve the friction performance of the contact surface of the friction pair.

SUMMARY OF THE INVENTION

The purpose of the present invention is to solve the problems mentioned in the background technology, in order to reduce the vibration of the tool during the milling process, enhance the edge strength of the tool, improve the machining accuracy of the tool and the surface quality of the workpiece during the milling process, and reduce the gap between the tool and the workpiece. The friction increases the cooling rate and service life of the tool to provide an end mill with a simple structure and a lower manufacturing cost.

The technical scheme of the present invention is as follows:

A variable helical unequal pitch end mill with surface micro-texture, the end mill comprising a shank portion (1) and a milling cutter head (2), the milling cutter head (2) being arranged on a cylindrical surface There are four circumferential milling edges (3), four bottom milling edges (4) are provided on the end face, and spiral chip flutes (4) are respectively provided between the circumferential milling edges (3) and the bottom milling edges (4). 5) and the crescent groove (6), multiple rows of circular micro-textures (7) arranged in a fan shape are arranged on the end face of the milling cutter, and a plurality of cooling channels (8) are arranged inside the milling cutter.

The peripheral milling edge (3) of the end mill adopts a variable helical structure, and global optimization is performed with the sum of the squares of the spectral amplitude deviations of the milling force as an objective function, and the optimization results are the helix angle β1 of the first tooth and the helix angle β _of the third tooth. ₃ is 40°, the second tooth helix angle β ₂ and the fourth tooth helix angle β ₄ are 41°.

A variable pitch structure is adopted between the two adjacent bottom milling edges (4) of the end mill, the included angles between the two adjacent bottom milling edges (4) are not equal, and the difference between the included angles does not exceed 8°, and the The sum of the included angles is 180°.

The end mill has a rake angle, a first relief angle, a second relief angle, a first end face relief angle, a second end face relief angle and an axial wedge angle; wherein the front angle is 7-15°, and the first relief angle is 12-15°, the second relief angle is 21-25°, the first end face relief angle is 1-3°, the second end face relief angle is 10-20°, the axial wedge angle is 1-5°, the structure design It can ensure the strength of the tool and reduce the milling resistance.

The end face of the end mill is provided with multiple rows of circular micro-textures (7) arranged in a fan shape, with a total of 6 rows, and the fan shape angle is 60-65°.

The end mill is provided with four cooling channels, the bottom of the milling cutter head (2) is provided with an outlet that communicates with the cooling channel (8), and the upper end surface of the shank portion (1) is provided with an outlet that communicates with the cooling channel (8). The cooling channel (8) is connected to the liquid inlet hole, and the outlet of the cooling channel (8) is fixedly provided with a filter screen (9).

To sum up, the present invention mainly has the following beneficial effects:

1) In this invention, by changing the helix angle, the milling time interval of the peripheral edge in the rotation direction of the end mill is changed, and the inter-tooth angle is changed to change the effective blade length of the blade and the feed per tooth of the tool, thereby destroying the cutting edge. The distribution of the vibration force in the frequency domain improves the machining stability of the tool.

2) In this invention, the friction between the tool and the workpiece is reduced through the end face relief angle and the end face micro-texture, and the milling force and milling heat during the milling process are reduced.

3) In this invention, the four cooling channels inside the tool and the filter screen at the outlet of the cooling channel can prevent small impurities from entering the cooling holes, increase the cooling speed of the tool, improve the continuous working time of the tool, and enhance the processing of the tool efficiency.

4) In this invention, the spiral chip removal groove and the crescent groove have better chip breaking and chip removal effect, which reduces the collision and friction between the chips and the tool, which is beneficial to improve the service life of the tool.

Description of drawings

Fig. 1 is the overall structure schematic diagram of the present invention;

Fig. 2 is the top view of the present invention;

Fig. 3 is the front view of the present invention;

FIG. 4 is a partial enlarged view of the present invention.

In the figure: 1. Shank; 2. Milling head; 3. Circumferential milling edge; 4. Bottom milling edge; 5. Spiral chip flute; 6. Crescent groove; 7. Surface microtexture; 9. Filters.

Detailed ways

Example 1

Referring to Fig. 1-Fig. 4, a variable helical unequal pitch end mill with surface micro-texture includes a shank portion (1) and a milling cutter head (2), the milling cutter head (2) is provided with four One peripheral milling edge (3) and four bottom milling edges (4), and between the peripheral milling edge (3) and the bottom milling edge (4) are respectively provided with a helical chip flute (5) and a crescent groove (6). The end face of the milling cutter is provided with a plurality of rows of circular micro-textures (7) arranged in a fan shape, and a plurality of cooling channels (8) are arranged inside the milling cutter.

Referring to Figure 1, the peripheral milling edge (3) of the end mill adopts a variable helical structure, and the global optimization is performed with the squared sum of the deviations of the spectral amplitudes of the milling force as the objective function. The optimization results are the first tooth helix angle β ₁ and the third The tooth helix angle β ₃ is 40°, the second tooth helix angle β ₂ and the fourth tooth helix angle β ₄ are 41°, and a helical chip flute (5) is provided between the milling edges (3) every adjacent two weeks , which is good for chip removal.

Referring to FIG. 2, the end face of the milling cutter is provided with multiple rows of circular micro-textures (7) arranged in a fan-shaped arrangement, with a total of 6 rows, and the fan-shaped angle is 60-65°. The circular micro-texture (7) can reduce the The contact area between the end face and the workpiece can also store cooling lubricants to reduce friction and reduce the milling force during machining.

Referring to Figure 2, a variable pitch structure is adopted between the two adjacent bottom milling edges (4) of the milling cutter, and the included angles between the two adjacent bottom milling edges (4) are not equal, and the difference between the included angles does not exceed 8° , the sum of the included angles is 180°, and a crescent groove (6) is arranged between the two adjacent bottom milling edges (4), which is conducive to chip breaking.

Referring to Figure 2, the end mill has a rake angle, a first relief angle, and a second relief angle, wherein the front angle is 7-15°, the first relief angle is 12-15°, and the second relief angle is 21-25° , The structure design can make the cutting edge sharp and reduce the friction between the flank and the workpiece.

Referring to Figure 3, the bottom of the end mill milling head (2) is provided with an outlet communicating with the cooling channel (8), and the upper end surface of the shank (1) is provided with an outlet communicating with the cooling channel (8). 8) Connected liquid inlet holes, a filter screen (9) is fixed inside the outlet of the cooling channel (8), and the mesh aperture of the filter screen (9) can be determined according to the material of the workpiece to be processed.

Referring to Figure 4, the end mill has a first end face relief angle, a second end face relief angle, and an axial wedge angle, wherein the first end face relief angle is 1-3°, the second end face relief angle is 10-20°, and the shaft The wedge angle is 1-5°. This structural design can improve the sharpness of the end face and reduce the friction between the end face and the workpiece.

The invention is suitable for milling grooves, stepped surfaces, etc., and the variable helical structure and variable pitch structure improve the milling stability during the processing; The friction between the end face and the workpiece improves the sharpness of the end face edge; through the spiral chip groove and the crescent groove, it has a better chip breaking and chip removal effect, reducing the collision friction between the chip and the tool; through the inner part of the milling cutter According to the above structure, the invention can reduce the vibration of the tool during processing, reduce the milling force and milling heat, improve the machining accuracy and efficiency of the tool, and increase the service life of the tool.

Claims (6)

1. The utility model provides a take little textured change spiral unequal tooth pitch end mill in surface, this end mill includes shank portion (1) and mills tool bit (2), its characterized in that: the milling cutter head (2) is provided with four peripheral milling edges (3) on a cylindrical surface, four bottom milling edges (4) on an end surface, spiral chip grooves (5) and crescent grooves (6) are respectively arranged between the peripheral milling edges (3) and the bottom milling edges (4), a plurality of rows of circular microtextures (7) which are arranged in a fan shape are arranged on the end surface of the milling cutter, and a plurality of cooling channels (8) are arranged in the milling cutter.

2. The variable helical unequal pitch end mill with surface microtexture according to claim 1, wherein: the peripheral milling edge (3) adopts a variable spiral structure, global optimization is carried out by taking the frequency spectrum amplitude deviation square sum of the milling force as a target function, and the optimization result is a first tooth helix angle beta₁And a third tooth helix angle beta₃Is 40 DEG, and the second tooth helix angle beta₂And a fourth tooth helix angle beta₄The angle is 41 degrees, and a spiral chip removal groove (5) is arranged between every two adjacent milling edges (3) so as to facilitate chip removal.

3. The variable helical unequal pitch end mill with surface microtexture according to claim 1, wherein: the variable tooth pitch structure is adopted between two adjacent bottom milling edges (4), included angles between the two adjacent bottom milling edges (4) are unequal, the included angle difference value is not more than 8 degrees, the included angle sum is 180 degrees, and a crescent groove (6) is arranged between the two adjacent bottom milling edges (4) to facilitate chip breaking.

4. The variable helical unequal pitch end mill with surface microtexture according to claim 1, wherein: the milling cutter head (2) is provided with a front angle, a first rear angle, a second rear angle, a first end surface rear angle, a second end surface rear angle and an axial wedge angle; the structure design can ensure the strength of the cutter, reduce the friction between the end face of the milling cutter and a workpiece, enhance the sharpness of the end face milling edge and reduce the milling resistance, wherein the front angle is 7-15 degrees, the first back angle is 12-15 degrees, the second back angle is 21-25 degrees, the first end face back angle is 1-3 degrees, the second end face back angle is 10-20 degrees, and the axial wedge angle is 1-5 degrees.

5. The variable helical unequal pitch end mill with surface microtexture according to claim 1, wherein: the end face of the milling cutter is provided with a plurality of rows of circular microtextures (7) which are arranged in a fan shape, the number of the rows is 6, the fan angle is 60-65 degrees, the circular microtextures (7) can reduce the contact area between the end face and a workpiece, and can also store cooling lubricating liquid to reduce friction and reduce milling force in the machining process.

6. The variable helical unequal pitch end mill with surface microtexture according to claim 1, wherein: the bottom of the milling cutter head (2) is provided with an outlet communicated with the cooling channel (8), the upper end face of the cutter handle portion (1) is provided with a liquid inlet hole communicated with the cooling channel (8), and a filter screen (9) is fixedly arranged inside the outlet of the cooling channel (8).

Images