The cutting edge on the round bar surface of the tungsten steel milling cutter is the main cutting edge, and the cutting edge on the end surface does not pass through the center, which is the secondary cutting edge. The workpiece is not suitable for axial feed movement. Before sharpening the knife, the grinding wheel needs to be inspected. If there is a grinding wheel jump, irregular cylindrical surface, excessive fillet, etc., it needs to be trimmed. Generally, the cylindrical surface of the grinding wheel can be trimmed with a grinding wheel trimmer (diamond trimmer, gear trimmer, etc.), or a waste grinding wheel with relatively large abrasive grain hardness can be used for trimming. If the side surface of the grinding wheel is already uneven, the grinding wheel can be replaced.

End Grinding Technology of Tungsten Steel Milling Cutter

 

 

Regardless of the number of tungsten steel milling cutters, the end face of the blade must be ground perpendicular to the axis first, which is the key to ensure that the highest point of the blade can be on the same plane. The method of sharpening the end face of the blade and verifying the verticality of the milling cutter axis is as follows:

 

① Visual inspection. With the help of a flat plate, put the tungsten steel milling cutter on the flat plate with the blade facing down, and observe the inclination angle from left to right. Then rotate the milling cutter 180° and observe its left and right inclination angle. In the same direction, if the inclination angles of the two observations are different, grinding is required until the inclination angles of the two observations in the same direction are the same. Then rotate the milling cutter 90°, repeat the above actions, and check the other direction.

 

②Correct with a square. Calibrate with a 90° square on a flat plate. Put the milling cutter and the square flat and observe whether there is a gap or whether the gap is even between the milling cutter and the square. Then judge the verticality of the milling cutter according to the gap. The knife is sharpened.

 

③ Self-calibration. Clamp the tungsten steel milling cutter on the chuck of the drilling machine or milling machine, put a waste grinding wheel under it, select the appropriate speed, turn on the machine tool, then move the milling cutter down, grind on the grinding wheel, and grind according to the grinding condition of the end face.

 

④Put the tungsten steel milling cutter with serious gaps on the cutting machine, and after adjustment, cut out the section of the milling cutter at one time.

 

⑤ Grind the tool on the milling cutter, and clamp it with three jaws or a taper sleeve. After adjustment, use a grinding wheel to grind the end face of the milling cutter to meet the requirements.

Tungsten steel milling cutter open cross flute technology

 

 

If there is no round groove on the front face of the four-blade tungsten steel milling cutter, it is necessary to use the rounded corner of the grinding wheel or on the grinding wheel cutting machine to re-open the cross groove along the direction of the cross spiral groove of the milling cutter, with a depth of about 1-2 mm (too deep and easy to cut). Cracking, too shallow and not easy to grind the secondary back corner). When grooving, pay attention that the side of the grinding wheel does not touch another cutting edge below (Note: This cross groove has chip removal function, if it is not opened, the inclination angle of the edge recessed in the middle should be increased).

Grinding Technology of End Face Cutting Edge of Tungsten Steel Milling Cutter

 

 

① When sharpening each blade face separately, take the tip of each blade as the benchmark and keep the blade tip as the principle, and then grind the rake angle (if there is no chipping, you can not grind it), the rear angle, and the secondary relief angle (if it is Large cutting volume requires better strength. It is recommended to increase the edge wedge angle) and edge inclination angle before grinding the knife.

 

②The choice of the relevant angle is 6°～8° for the relief angle, (30°～45° for the auxiliary relief angle) and 1°～3° for the inclination angle. The choice of relief angle is to be changed according to the hardness of the workpiece. The greater the hardness of the material, the smaller the angle; the principle of the angle selection of the blade inclination angle is that all four blades must be recessed in the middle, and the middle of the blade must not protrude. If the plane is not milled out, it will definitely be uneven. Moreover, the more concave the middle of the blade, the better. In fact, the four blades are all concave toward the middle. The flatter the angle, the better the roughness accuracy. At this time, the deeper the processing depth (for example, greater than 2mm but within the allowable range), the better the roughness accuracy, because the entire cutting edge is involved in cutting, and the surface quality formed is better.

 

③ After the sharpening is completed, stand the tungsten steel milling cutter on a platform. If the axis is vertical, all the blade tips can be aligned, and the deflection angle of the blade can be evenly centered, so that it can meet the requirements. At this time, it can also be calibrated with a 90° square on a flat plate. After laying it flat, observe whether there is a gap between the milling cutter and the square or whether the gap is even. Generally, first observe the two relatively higher feet (the two feet that touch the bottom first), and if they are not vertical, grind the higher feet until the two opposite feet are the same height (that is, vertical). There is a height difference with the other two opposite feet and the milling cutter will swing. At this point, grind down the two higher feet at the same time. Similarly, rotate the milling cutter 90° to observe the verticality of the other two opposite feet, and finally make the four feet touch the bottom at the same time and make the milling cutter vertical. Milling cutter after sharpening.

 

In manual sharpening, the height and angles of the blade are not easy to grasp, and it varies from person to person during training. Just pay attention to grinding out a little back angle, but it must be concave in the middle, so that even if the cutting edge is not flat, as long as the cutting edge It is enough that the tip is at the highest point, which can also ensure that the sharpened tool can be milled normally. In addition, if it is not the case of clearing the inner cavity, you can also grind the chamfer at the tip of the tool to a size greater than 0.2mm to increase the strength of the tip.

 

Tungsten steel milling cutter main edge (ie side edge) sharpening technology

 

 

If the main edge of the tungsten steel milling cutter is worn out, it should be ground along the helical line on the grinding wheel (the diameter of the grinding wheel is smaller and better) (it is difficult for beginners to grind well). However, there is generally a taper after grinding, and the smaller the taper, the higher the operating level.