Development of high-efficiency new drill type special sharpening machine

Drilling is one of the most important processes in metal cutting. Ordinary twist drills greatly limit the improvement of drilling efficiency due to defects in the original structure. China's group drills are recognized as one of the world's best drills with excellent performance. However, the group drills have complex structures and difficult grinding, which are not widely used in production. In recent years, a series of advanced drill sharpening machines and group drill sharpening machines have been developed at home and abroad, which can sharpen some advanced drill types and group drills. However, these sharpening machines are complicated in structure and expensive, which is difficult for most manufacturers to accept. In the early 1990s, the Japanese company Jingjing developed a new type of drill and developed a corresponding sharpening machine, which quickly gained market recognition. The fine well drill is not as good as the drill of our country, but because of its simple structure and low price, the fine drill bit is quickly applied in production. Therefore, it is of great significance to develop an efficient new drill type and to develop a sharpening machine that is easy to operate and inexpensive.

1, a new type of drilling proposed <br> <br> drilling group improved drilling efficiency. However, the analysis found that the group drill still has certain shortcomings: 1) It is difficult to achieve complete symmetry of the left and right cutting edges during sharpening, so that a large radial force will be generated during the drilling process, the bit wear is accelerated and the aperture is enlarged. 2) The chips of the group drill are divided into two in width, the speed difference between the outer end and the inner end of the chip is still large, and the additional deformation during cutting is still large; 3) the structure is complicated and the sharpening is difficult.

We optimized the standard group drill and got a new drill type. The cross-blade grinding method of the new drill bit is the same as that of the group drill. At the same time, we use a better chip-distributing method, which makes the drilling performance of the new drill type better than the group drill, and simplifies the structure, making the sharpening convenient, among which the small diameter (5<Ø<20) The structure of the drill bit is shown in Figure 1(a). The left side of the drill has a short arc edge, which is about 1/3 of the length of the entire cutting edge. The outer edge is longer, about 2/3 of the length of the entire cutting edge; the right circular arc is longer, about the length of the entire cutting edge. 2/3, the outer edge is shorter, about 1/3 of the length of the entire cutting edge; at the same time, the left outer edge is lower than the right outer edge (the height difference should be greater than the drilling feed f, the dotted line in the figure is the right edge) Higher than the part); at the same time simplify the flank and replace the helicoid with a plane. The structure of the large diameter drill (Ø>20) is shown in Figure 1(b). The left circular arc is about 1/5 of the length of the entire cutting edge, and the outer edge is about 4/5 of the length of the entire cutting edge. The arc edge is about 2/5 of the length of the entire cutting edge, and the outer edge is about 3/5 of the length of the entire cutting edge; the chip is opened on the outer edge of the higher and shorter side, and the width is about the length of the entire cutting edge. 1/5, the depth is greater than the feed rate. The cutting force is symmetrically distributed throughout the drilling process. When the drill bit first comes into contact with the workpiece, the shortened transverse blade plays a good centering effect; after that, the symmetrical circular edge starts to cut into the workpiece, and the cutting width is reduced due to the shortening of the circular arc edge; when the drill bits on both sides contact the workpiece The outer blade starts to participate in the cutting. The outer edge of the right side of the drill bit is higher than the outer edge of the left side, and the outer edge of the left side is longer than the outer edge of the right side. Therefore, the outer edge of the right side of the drill hole only cuts the outer circle, and the outer edge of the left side only cuts the middle one. ring. It can be seen that the special structure of the drill bit ensures a symmetrical distribution of the cutting forces on the cutting edge. For large diameter drill bits, the chips are divided into five segments in the direction of the main cutting edge to better reduce the cutting deformation. Other properties are the same as for small and medium diameter drill bits.

Next page

701 Biological Microscope

701 Biological Microscope,Microscope For Biology Students,Microscope For Soil Biology,Biology Lab Microscope

Ningbo Beilun Kalinu Optoelectronic Technology Co.,Ltd , https://www.nbyxmicroscope.com