CN115121851A - A discrete edge variable pitch end mill - Google Patents

Abstract

The present invention is a discrete edge variable pitch end milling cutter. The milling cutter structure includes a shank portion and a blade portion. The blade portion is provided with a number of chip separation grooves to form a discrete edge structure, which is easy to separate chips and prevents chips from being retained. By changing the relief angle on the adjacent two helical cutting edges, it is to reduce the eccentricity and improve the dynamic balance. In the cutting process, since the traditional tool is prone to cutting vibration when cutting the workpiece, the structure of variable inter-tooth angle plus variable helix angle can effectively reduce the probability of chatter vibration and improve the surface processing quality. The invention has the advantages of preventing debris retention, stable cutting, prolonging the service life of the tool, and high processing efficiency.

Description

A discrete edge variable pitch end mill

technical field

The invention relates to the field of machining tool design, in particular to a discrete edge variable pitch end mill.

Background technique

Milling cutter is a very common production and processing tool today. When a traditional equal helical end mill is used to process a workpiece, the tool works at a fixed frequency, which causes the workpiece to produce chatter during the processing process and causes the tool to generate greater vibration. , resulting in tool damage, and when the tool is cutting, the debris cannot be discharged in time, which affects the processing efficiency. In order to cope with this situation, the structure of variable helix or variable inter-tooth angle is now adopted, but this will cause different cutting loads on adjacent cutting edges, and at the same time, the peak value of cutting force it will experience will also be different, and this It is also related to the selection of the helix angle and the inter-tooth angle, so it is necessary to choose the size reasonably. In order to improve this situation, this invention milling cutter is proposed, which plays a positive role in promoting efficient cutting.

SUMMARY OF THE INVENTION

The purpose of the present invention is to solve the above problems, design a discrete edge variable pitch end mill, by changing the helix angle and the inter-tooth angle, thereby indirectly changing the pitch and the waveform of the cutting force, reducing the tool vibration, and prolonging the tool life, And there is a chip groove on the helical cutting edge to solve the problem of chip discharge.

The technical scheme of the present invention is as follows:

The structure of the discrete edge variable pitch end mill includes a shank, a blade with a helical cutting edge, a discrete edge and a chip groove. The key is: the helix angle difference between the adjacent helical cutting edges of the blade is: 2°, the inter-tooth angle between the cutter teeth is also different, and there are discrete edges and chip grooves on the edges.

The discrete edge variable pitch end mill is a 4-tooth cutting edge, the adjacent helix angles are 36°, 38°, and the rake angle is 10°.

The radial section groove shape curve of the discrete edge variable pitch end mill is composed of three tangent arcs, the sizes of which are respectively 13mm, 1.6mm and 5.7mm.

The clearance angles of adjacent helical cutting edges of the discrete edge variable pitch end mill are 8° and 15° respectively.

The outer diameter of the discrete edge variable pitch end mill is 20mm, the length of the blade is 40mm, the length of the shank is 60mm, the slot opening angles are also different, 63° and 72°, respectively, and the inter-tooth angles are 87° and 93°, respectively. The radius of the central groove is 1mm.

The width and depth of the chip splitting grooves of the adjacent helical cutting edges of the discrete edge variable pitch end mill show a decreasing trend with the axial upward direction of the milling cutter, and the chip splitting grooves on the two edges decrease equally. form a staggered distribution.

The beneficial effects of the invention are that it has the advantages of high rotational speed, reduced cutting vibration, extended tool life, easy chip separation, prevention of chip retention, improved surface processing quality, stable cutting, and high processing efficiency.

Description of drawings

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

Figure 2 is a schematic diagram of the arrangement and distribution of the chip splitter structure of the present invention

Figure 3 is a schematic diagram of the radial cross-section groove curve of the discrete edge variable pitch end mill of the present invention

Description of drawing numbers: shank 1, blade 2, helical cutting edge 3, central groove 4, helical cutting edge 5, chip groove 6

Detailed ways

The discrete edge variable pitch end mill as shown in FIG. 1 includes a shank 1 and a blade 2 , the blade includes a helical cutting edge 3 and a helical cutting edge 5 . Among them, discrete edges and chip flutes are distributed on the helical cutting edge, and the central groove 4 is located at the center of the top of the milling cutter.

As shown in Fig. ₂ , the chip groove depth H1 on the helical cutting edge ₃ of the discrete edge variable pitch end mill is 1.4mm, _H2 is 1.1mm, the groove width W1 is 2.0mm, and W2 is _1.25mm , that is, the size decreases equally along the axial upward direction of the milling cutter, the groove depths are 1.4mm, 1.3mm, 1.2mm, 1.1mm, and the groove widths are 1.4mm, 1.3mm, 1.2mm, 1.1mm, and the groove spacing Both are 5.0mm.

As shown in Figure 2, the chip splitter groove depth _H3 on the helical cutting edge ₅ of the discrete edge variable pitch end mill is 1.4mm, H4 is 1.0mm, the groove width _W3 is 2.0mm, and _W4 is 1.0mm , that is, the size decreases with equal difference along the axial upward direction of the milling cutter, the groove depth is 1.4mm, 1.3mm, 1.2mm, 1.1mm, 1.0mm, and the groove width is 2.0mm, 1.75mm, 1.5mm, 1.25mm. , 1.0mm, and the groove spacing is 5.0mm.

For the discrete edge variable pitch end mill as shown in Figure 3, the cutter head groove curve is composed of three arcs, and the radii of the three tangent arcs correspond to the arc R ₁ is 13mm, and the arc R ₂ is 1.6mm. , The arc R ₃ is 5.7mm. The inter-tooth angle _θ1 of the milling cutter is 93°, and θ2 is 87°, of which the tool rake angle _γ0 is ₁₀ °, the central groove radius r is 1mm, the slot opening angle _γ1 is ₇₂ °, and γ2 is 63°.

For the discrete edge variable pitch end mill shown in Figure 3, the clearance angles of adjacent helical cutting edges are different, α ₁ =15°, α ₂ =8°.

The invention is suitable for milling aluminum alloy materials with discrete edge variable pitch end mills. By changing the relief angle of two adjacent spiral cutting edges, the wear between the flank face of the milling cutter and the machining surface of the workpiece is improved, and the surface machining is improved. quality and dynamic balance. The structure of variable helical, variable pitch and chip splitter reduces cutting vibration, prolongs tool life, and makes cutting more stable, and the chip splitter of the previous helical cutting edge and the chip splitter of the next helical cutting edge are not On the same straight line, staggered distribution is formed, which is easy to separate chips, prevents chips from staying, and improves processing efficiency.

Claims (5)

1. a discrete edge variable pitch end mill, its structure comprises a shank, a blade with a helical cutting edge and a chip groove, it is characterized in that: the helix angle of the adjacent helical cutting edge on the described blade There is a difference between the clearance angle and the clearance angle, and the number of chip splitters on adjacent helical cutting edges is different, and the groove depth and groove width of different chip splitters also change. 2. a kind of discrete edge variable pitch end mill according to claim 1, it is characterized in that: described milling cutter is 4 tooth blade, the rake angle is 10°, and the clearance angle of adjacent cutting edges is 8° respectively and 15°, the helix angles of adjacent helical cutting edges are 36° and 38°, respectively. 3. A kind of discrete edge variable pitch end mill according to claim 1, it is characterized in that: described end mill radial section groove shape curve is composed of three tangent arcs, and its size is 13mm, 1.6mm, 5.7mm, the center groove radius is 1mm. 4. A discrete edge variable pitch end mill according to claim 1, characterized in that: when the chip splitters are distributed along the axial upward direction of the milling cutter, the number of chip splitters of adjacent helical cutting edges is different, The width and depth of the chip splitter are decreasing. 5. A kind of discrete edge variable pitch end mill according to claim 1 is characterized in that: the inter-tooth angle of adjacent cutter teeth is unequal, the inter-tooth angle of the symmetrical position is equal, and the angles are respectively 87°, 93° °.

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