CN207103937U - Reinforced Round Nose End Mills - Google Patents

Abstract

The utility model discloses a strenghthened type round nose end mill, including cylindric cutter arbor, the perisporium of cutter arbor lower part and lower terminal surface shaping respectively have many side blades and the end sword that distributes around the axis of cutter arbor, and the perisporium of cutter arbor is located and has seted up between the adjacent side blade and hold bits sword groove, and the circular arc is passed through and is formed convex knife tip between the back cutting edge of every side blade and every end sword, and the region of the adjacent knife tip of preceding cutting edge face of every side blade passes through with convex knife tip circular arc. The utility model discloses can improve the front edge face of side sword and the structural strength of convex knife tip transition department to when processing the work piece fast, reduce the damage degree of the front edge face of side sword and the transition department of convex knife tip, thereby improve strenghthened type round nose end mill's life.

Description

Reinforced Round Nose End Mills

technical field

The utility model relates to the technical field of milling cutters, in particular to a reinforced round nose end milling cutter.

Background technique

End mills are mainly used to process planes, stepped surfaces and grooves on workpieces. Among many kinds of end mills, round nose end mills are most suitable for rapid machining, and are widely used in roughing workpieces or machining shapes with arc corners. Existing round nose end mills generally have a cylindrical cutter bar. The peripheral wall and lower end surface of the lower part of the cutter bar are respectively formed with side edges and end edges distributed around its axis. The peripheral walls of the cutter bar are located on adjacent sides. There is a chip flute between the blades for chip removal. The side edge extends spirally from the lower end face of the tool shank to the upper end face, and the rear edge surface (or flank face) of the side edge and the end edge arc transition to form an arc-shaped tip with an arc of a quarter circle. When the round nose end mill rotates and feeds with the cutter shaft of the milling machine, it can mill the workpiece fixed on the table.

However, the existing round nose end mills still have the following deficiencies: 1. The rake face (or rake face) of the side edge of the round nose end mill and the arc-shaped tool tip are roughly at right angles, and the right angle transition is The strength is still not strong enough, and the possibility of damage at the right-angle transition is still high during rapid processing. 2. The core diameter of the round nose end mill (the core diameter refers to the diameter of the imaginary circle on the axis of the round rod at the center of the circle and tangent to all the edge grooves on the cutter rod, also known as the core thickness) is small, It is about 0.6 times the diameter of the tool holder, and the structural rigidity is small. 3. The helical angle of the side edge is relatively large, generally about 35°, which causes the side edge to bear a large vertical resistance when it moves along the axial direction of the workpiece with the tool bar. On the one hand, it will increase the damage of the side edge, and on the other hand On the other hand, the processing efficiency will be reduced.

Utility model content

The main purpose of the utility model is to provide a reinforced round nose end mill, which aims to improve the strength of the transition between the side edge and the arc tip of the round nose end mill.

In order to achieve the above purpose, the utility model proposes a reinforced round nose end mill, which includes a cylindrical cutter bar. The peripheral wall and the lower end surface of the lower part of the cutter bar are respectively formed with a plurality of side edges and end edges distributed around the axis of the cutter bar. Edge, the peripheral wall of the tool bar is located between adjacent side edges to open a chip flute, the rear edge of each side edge and each end edge have a circular arc transition and form a circular arc-shaped tip, each The region of the leading edge surface of the side edge adjacent to the tip of the knife transitions with the arc-shaped tip of the knife.

The technical solution of the utility model is to improve the transition between the front edge surface of the side edge and the arc-shaped knife tip by setting the area adjacent to the knife tip of each side edge and the arc-shaped knife tip. The structural strength at the center can reduce the degree of damage at the transition between the front edge surface of the side edge and the arc-shaped tool tip when the workpiece is processed rapidly, thereby improving the service life of the reinforced round nose end mill.

Description of drawings

Fig. 1 is the three-dimensional schematic view of the utility model reinforced round nose end mill;

Fig. 2 is the front view of the reinforced round nose end mill of the utility model;

Fig. 3 is an enlarged detailed view of part A of Fig. 2;

Fig. 4 is the sectional view along B-B direction of Fig. 2;

FIG. 5 is an enlarged detail view of part C of FIG. 4 .

Detailed ways

The technical solutions in the embodiments of the utility model will be clearly and completely described below in conjunction with the accompanying drawings. Apparently, the described embodiments are only part of the embodiments of the utility model, not all of them. Based on the embodiments of the present utility model, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the scope of protection of the present utility model.

It should be noted that if there are directional indications (such as up, down, left, right, front, back, top, bottom, inside, outside, vertical, horizontal, vertical, counterclockwise, clockwise, Circumferential, radial, axial...), the directional indication is only used to explain the relative positional relationship, movement, etc. When the attitude changes, the directional indication changes accordingly.

In addition, if there is a description related to "first" or "second" in the embodiment of the present utility model, the description of "first" or "second" is only for the purpose of description, and should not be interpreted as an indication or Implying their relative importance or implying the number of technical features indicated. Thus, the features defined as "first" and "second" may explicitly or implicitly include at least one of these features. In addition, the technical solutions of the various embodiments can be combined with each other, but it must be based on the realization of those skilled in the art. When the combination of technical solutions is contradictory or cannot be realized, it should be considered that the combination of technical solutions does not exist , also not within the scope of protection required by the utility model.

The utility model provides a reinforced round nose end mill.

In the embodiment of the present utility model, as shown in Figures 1 to 5, the reinforced round nose end mill includes a cylindrical cutter bar 1, and the cutter bar 1 can be installed on the cutter shaft (not shown) of a milling machine (not shown). shown) and moves with the cutter shaft, the peripheral wall and lower end surface of the lower part of the cutter bar 1 are respectively formed with a plurality of side edges 2 and end edges 3 distributed around the axis of the cutter bar 1, and the peripheral wall of the cutter bar 1 is located on the adjacent side edges A chip flute 4 is opened between the 2 for chip removal. The side edge 2 spirally extends from the lower end face of the cutter bar 1 to the upper end face, and the arc transition between the rear edge face of each side edge 2 and each end edge 3 forms a circular arc-shaped tip 5, and each side edge The area 6 adjacent to the cutting edge 5 of the front edge surface of the cutting edge 2 and the arc-shaped cutting edge 5 have a circular arc transition. To improve the structural strength of the transition between the front edge surface of the side edge 2 and the arc-shaped tool tip 5, to reduce the gap between the front edge surface of the side edge 2 and the arc-shaped tool tip 5 when rapidly processing workpieces (not shown). The degree of damage at the transition, thereby increasing the service life of the reinforced round nose end mill.

In the embodiment of the utility model, the quantity of the side edge 2 and the end edge 3 can be determined according to the actual situation (such as the diameter of the tool bar 1, the material of the tool bar 1 or the workpiece to be processed, etc.), and can be respectively two , three, four, five or more, the plurality of side edges 2 and end edges 3 are preferably evenly distributed around the axis of the cutter bar 1, so as to ensure the stability of the rotation of the cutter bar 1. As shown in Fig. 2 and Fig. 4, it is the case where there are four side cutting edges 2 and four end cutting edges 3 each.

Further, the core diameter (or core thickness) d of the cutter bar 1 is 0.79 to 0.8 times the outer diameter D of the cutter bar 1, for example, 0.790 times, 0.791 times, 0.792 times, 0.793 times, 0.794 times, 0.795 times, 0.796 times times, 0.797 times, 0.798 times, 0.799 times or 0.8 times, etc., preferably 0.793 times or 0.794 times. Taking a cutter shank whose diameter D is 12MM as an example, the core diameter d is preferably 9.52±0.03MM. At this time, the rigidity of the reinforced round nose end mill of the utility model is better. Optionally, the rounded tip has a radius of 1MM.

Specifically, as shown in Figure 2, the side edge extends helically from the lower end surface of the cutter bar 1 to the upper end surface, and the helix angle a is 14° to 16°, such as 14°, 15° or 16°, preferably 15°, here The helical angle is relatively small, so that the side edge bears a small vertical resistance when moving along the axial direction of the workpiece with the tool holder 1. On the one hand, the damage to the side edge 2 can be reduced, and on the other hand, the processing efficiency can be improved.

In the embodiment of the present invention, as shown in FIG. 5 , the rake angle of the side edge 2 is a negative rake angle, which can improve the cutting strength of the side edge 2 . The specific angle β of the negative rake angle is -10° to -15°, for example -10°, -11°, -12°, -13°, -14° or -15°, preferably -12°.

Specifically, the material of the cutter bar 1 can be selected according to the material of the workpiece to be processed and the predetermined feed rate, for example, it is made of high-speed tool steel or hard alloy, preferably tungsten steel.

In the embodiment of the present invention, the entire surface of the cutter bar 1 or at least the lower surface is coated with a coating with better high temperature resistance and wear resistance, so as to increase the service life of the cutter. Specifically, the coating may be a silicon nitride coating, a titanium nitride coating, or an aluminum nitride titanium coating, and the like.

The above is only a preferred embodiment of the utility model, and does not limit the patent scope of the utility model. Under the utility model concept of the utility model, the equivalent structural transformation made by using the specification of the utility model and the contents of the accompanying drawings, Or directly/indirectly used in other related technical fields are all included in the patent protection scope of the present utility model.

Claims (10)

1. A reinforced round nose end mill, including a cylindrical cutter bar, the peripheral wall and lower end surface of the lower part of the cutter bar are respectively formed with a plurality of side edges and end edges distributed around the axis of the cutter bar, and the peripheral wall of the cutter bar is located at There is a chip flute between the adjacent side edges, and the arc transition between the back edge of each side edge and each end edge forms an arc-shaped tool tip, which is characterized in that: each side edge The area adjacent to the tip of the rake face transitions with the arc-shaped tip of the tool. 2. The reinforced round nose end mill according to claim 1, characterized in that: the number of side edges and end edges is two, three, four, or five, and the plurality of side edges and end edges are wound around the cutter The axes of the rods are evenly distributed. 3. The reinforced round nose end mill according to claim 1, characterized in that: the core diameter d of the cutter shank is 0.79-0.8 times the outer diameter D of the cutter shank. 4. The reinforced round nose end mill according to claim 3, characterized in that: the core diameter d of the cutter shank is 0.793 times or 0.794 times the outer diameter D of the cutter shank. 5 . The reinforced round nose end mill according to claim 1 , wherein the side cutting edge spirally extends from the lower end face of the cutter bar to the upper end face, and the helical angle a is 14°-16°. 6. The reinforced round nose end mill according to claim 5, characterized in that: the helix angle a of the side cutting edge is 15°. 7. The reinforced round nose end mill according to claim 1, characterized in that: the tool holder is made of tungsten steel. 8. The reinforced round nose end mill according to claim 1, characterized in that: the entire surface or at least the lower surface of the cutter bar is coated with silicon nitride coating, nitrided silicon nitride coating, etc. Titanium coating or titanium aluminum nitrogen coating. 9. The reinforced round nose end mill according to any one of claims 1 to 8, characterized in that: the rake angle of the side cutting edge is a negative rake angle, and the specific angle β of the negative rake angle is -10°～-15° °. 10. The reinforced round nose end mill according to claim 9, wherein the specific angle β of the negative rake angle is -12°.