1 Introduction
2 Inspection of new carbide saw blade
2.1 Appearance and dimensions
2.2 Tensile test of carbide saw blade
3.Selection of sharpening time
4.Sharpening technology and key technology
4.1 Sharpening part
4.2 Choose the suitable diamond grinding wheels for sharpening carbide saw blades
4.3 Saw tooth angle maintenance
4.4 Grinding parameters
4.5 Sharpening equipment
5 Sawtooth sharpening
5.1 Tooth back face sharpening
5.2 Tooth front face sharpening
5.3 Tooth side sharpening
6 Keep and maintenance of carbide saw blade
Conclusion
1 Introduction
Carbide saw blade is usually used for wood products. How to sharpen the carbide saw blade correctly is related to the sharpness and service life of carbide saw blade. Therefore, it is important to choose suitable diamond grinding wheels for sharpening carbide saw blades except for technology.
In the actual production and use of carbide saw blades, owing to the unreasonable sharpening technology or improper use of the diamond grinding wheel, the carbide saw blades cannot meet the technical quality requirements, and the service life cannot reach half of the design life. It not only affects the quality of carbide saw blade machining, but also increases the cost.
So, sharpening is an important step in the whole production and use of carbide saw blades. It should be mastered comprehensively sharpening technology from the selection to maintenance of carbide saw blade. And choose the suitable diamond grinding wheels for sharpening carbide saw blades.
2 Inspection of new carbide saw blade
2.1 Appearance and dimensions
Pay attention to the tooth shape, number and dimension of carbide saw blade and see whether those meet the requirements. Carefully check whether there are scratches, burrs, incomplete tooth shape, blunt tooth edge, and rough surface.
2.2 Tensile test of carbide saw blade
Install the new carbide saw blade on the saw machine and start the machine to rotate. If there is abnormal vibration, swing or whistle, it shows the quality of carbide saw blade is unqualified.
3.Selection of sharpening time
It is very important to master the sharpening time of carbide saw blade, which is directly related to the processing quality and cost. First of all, check whether the surface quality of carbide saw blade can meet the requirements. Secondly, the wear of saw teeth is not serious. Because carbide has high hardness and wear resistance,
once the wear is serious, it is difficult to sharpen, which not only increases the sharpening time, but also the saw teeth wear early and increases the sharpening power. According to the practical production experience, the saw teeth should be sharpened when the following situations occur.
3.1 If cutting quality does not meet the requirements such as product surface fuzzing and rough. It needs to be sharpened immediately.
3.2 When the cutting edge is shortened more than 0.2mm, it must be sharpened. It cannot measure the cutting edge shortening with a microscope in actual production, usually use the magnifier for checking. When there is a white line in the teeth, it needs to be sharpened.
3.3 When saw teeth breaks
3.4 When cutting power increases sharply, it is better not to wait for this situation to happen before sharpening the saw blade.
4.Sharpening technology and key technology
4.1 Sharpening part
The sawtooth sharpening of carbide saw blade is mainly for the back, supplemented by sharpening the front, and there is no special requirement for tooth side. In addition, owing to the side relief angle is much smaller than the edge clearance angle, and the reduction of the top tooth has little effect on the width of the saw set. So the sharpening key point is the back of the tooth.
4.2 Choose the suitable diamond grinding wheels for sharpening carbide saw blades
4.2.1 Analysis of diamond grinding wheel for sharpening carbide saw blade bond
4.2.1.1 Resin bond diamond grinding wheels
The bond strength of this type of diamond grinding wheel is weaker than that of other wheels. The self-sharpening for carbide saw blade is better, no blocking. The grinding force and grinding temperature are low. Wear resistance is poor, and the wear of abrasive tools is high and is not suitable for heavy load grinding.
4.2.1.2 Vitrified bond diamond grinding wheels
The wear resistance and bonding strength of vitrified bond diamond grinding wheel is higher than that of resin bond diamond grinding wheel, and the cutting is sharper and efficiency is higher when grinding. It has better control for heating, blocking, thermal expansion and accuracy. But the surface of saw blade after sharpening is rough and the cost is higher than other wheels.
4.2.1.3 Metal bond diamond grinding wheels
Metal bond diamond grinding wheel has high bonding strength and good wear resistance, low wear ratio when sharpening, long service life, low cost, and withstand big loads. But self-sharpening is low and blocks easily.
4.3 Saw tooth angle maintenance
The front and rear angles of carbide saw blade has been determined before leaving the factory. Therefore, it should keep the included angle between the grinding wheel and carbide saw blade unchanged during the re-grinding process, which is also the requirement of a feature of carbide saw blade.
After sharpening the carbide saw blade, the angle between the front and rear keep unchanged. The included angle between the working face of the diamond grinding wheel and the front and back teeth of the required grinding face is equal to the grinding angle. The movement distance of the diamond grinding wheel is equal to stock removal.
To make the working face of diamond grinding wheel parallel to the saw teeth surface, gently contact, and then make the working face of diamond grinding wheel leaves away from the tooth surface, and then adjust the angle of the working face of diamond grinding wheel according to the sharpening angle, and finally make the working face of wheel contact with the tooth surface.
4.4 Grinding parameters
The grinding parameters refer to grinding heat, feed speed, and grinding depth. The higher the grinding speed, the higher the grinding heat, the easier the tooth edge burns. The higher the feed speed, the larger the grinding heat and residual stress of the tool, the larger the wear loss of the grinding wheel. To minimize the number of abrasive grains falling off and improve the surface grinding quality, it should reduce the feed speed. The grinding depth is 0.01-0.05mm in rough grinding and the feed speed is 1-2 m/min.
4.5 Sharpening equipment
There are 3 kinds of equipment for sharpening carbide saw blade. They are automatic saw sharpener, manual saw sharpener, and universal edge grinder. The automatic saw sharpener is divided into numerical control type and general automatic type.
5 Sawtooth sharpening
5.1 Tooth back face sharpening
Usually, dish grinding wheels are used. When sharpening staggered teeth or trapezoidal teeth, it needs to do tilt adjustment for the axis of the diamond grinding wheel or the axis of the saw table clamped with a saw blade. The angle between the grinding wheel working face and the back teeth face is equal to the bevel angle of the back teeth, which should be sharpened staggered every other tooth. When sharpening the back of the flat teeth, the grinding wheel working face should be parallel to the back teeth face.
5.2 Tooth front face sharpening
Usually, dish grinding wheels are used. When the front bevel angle is equal to zero, the diamond grinding wheel working face and tooth front face is perpendicular to the horizontal surface. When sharpening the saw blade with a front bevel angle, the saw table or grinding wheel should be inclined at an angle equal to the front bevel angle. In addition, staggered sharpen every other tooth.
5.3 Tooth side sharpening
Usually, the tooth side does not need to be sharpened. If need to sharpen, the dish grinding wheel working face should be inclined to meet the requirements of sawing angle and side rear angle. Plant grinding wheel can also be used for sharpening. The purpose of tooth side sharpening is to make the tooth side edge on the same cutting surface in order to improve the sharpening quality.
The thickness center of the saw body must be on the same surface as the axis of the grinding wheel, otherwise, the position of the left and right teeth tips will be different. When adjusting the machine tool, first adjust the height of the two to be exactly the same, and then adjust the whole bevel angle.
6. Keep and maintenance of carbide saw blade
When installing the carbide saw blade on the saw axle, it is not allowed to place the saw blade on a rigid table, or make the saw blade touch hard objects. Place every saw blade on the cushion when stored, in order to avoid crushed between the carbide saw teeth or with other hard objects. In the process of sharpening the saw blade, it should protect the saw teeth from damage, and remove the resin, iron chips and other impurities attached to the side of the saw teeth.
Conclusion:
The sharpening process of carbide saw blade is different from that of the conventional circular saw blade. When the grinding rate is high, the grinding heat is high. This not only makes the carbide saw blade crack but also the sharpening quality is not good. Therefore, when choosing the grinding wheel, it should be chosen the professional diamond grinding wheels for sharpening carbide saw blade. At present, resin bond diamond grinding wheels are used.
When sharpening, we should be patient. When pushing and pulling the carbide saw blade, it should be smooth and gentle. It will prolong the service life, reduce the manufacturing cost and improve the labor efficiency by reasonable sharpening.
