How to correctly choose the series parameters of cemented carbide circular saw blades

2019-10-23 管理员 Read 157
Introduction: Cemented carbide saw blades include various parameters such as the type of alloy cutter head, the material of the substrate, the diameter, the number of teeth, the thickness, the tooth profile, the angle, and the aperture. These parameters determine the processing capacity and cutting performance of the saw blade. 

Cemented carbide saw blades include various parameters such as the type of alloy blade, the material of the substrate, the diameter, the number of teeth, the thickness, the tooth profile, the angle, and the aperture. These parameters determine the processing capacity and cutting performance of the saw blade. When choosing a saw blade, the saw blade should be selected correctly according to the type of sawing material, the thickness, the speed of sawing, the direction of sawing, the feeding speed, and the width of the saw road.
The alloy particles used in high-quality saw blades are thicker and larger, because such alloy saw teeth can be sharpened repeatedly and have a long service life. The quality of cemented carbide joints is also very important. The weld seam should be thin and well-proportioned so that the teeth can withstand Greater cutting force.

(1) Selection of cemented carbide types Commonly used cemented carbide types include tungsten-cobalt (code YG) and tungsten-titanium (code YT). Because tungsten-cobalt-based cemented carbide has better impact resistance, it is more widely used in the wood processing industry. The commonly used model in wood processing is YG8-YG15. The number after YG indicates the percentage of cobalt content. As the cobalt content increases, the impact toughness and flexural strength of the alloy will increase, but the hardness and wear resistance will decrease. Choose according to the actual situation.
(2) The choice of the substrate The quality of the saw blade is very important. Because the saw blade adjusts its rotation, it has to transmit cutting force and maintain working stability. A good saw blade not only has static geometric dimensions and accuracy, but more importantly, its dynamic characteristics.
When the saw blade is continuously cut, the heat generated by the alloy saw tooth cutting will be transmitted to the saw board, which will increase the temperature of the saw board. In this case, the high-quality saw board can maintain the precision of the statement, while the poor-quality saw The blade will warp the saw board, which affects the precision of sawing. The dynamic stability of the saw board is particularly important when several saw blades are used in groups.
1.65Mn spring steel has good elasticity and plasticity, economical material, good heat treatment hardenability, low heating temperature, easy deformation, and can be used for saw blades that require low cutting requirements.
2. Carbon tool steel has high carbon content and high thermal conductivity, but its hardness and wear resistance drop sharply when exposed to 200℃-250℃ temperature, heat treatment deformation is large, hardenability is poor, and long tempering time is easy to crack. Manufacture economical materials for tools such as T8A, T10A, T12A, etc.
3. Compared with carbon tool steel, alloy tool steel has better heat resistance, wear resistance and better handling performance. The heat deformation temperature is 300℃-400℃, which is suitable for manufacturing high-grade alloy circular saw blades.
4. High-speed tool steel has good hardenability, strong hardness and rigidity, and less heat deformation. It belongs to ultra-high strength steel, and its thermoplasticity is stable. It is suitable for manufacturing high-grade ultra-thin saw blades.
(3) Selection of the sawtooth angle The angle parameters of the sawtooth part are more complicated and the most professional, and the correct selection of the angle parameters of the saw blade is the key to determining the quality of sawing. The most important angle parameters are the rake angle, the rear angle and the wedge angle. The rake angle mainly affects the force consumed by sawing wood chips. The larger the rake angle, the better the sharpness of the saw tooth cutting, the lighter the sawing, and the more labor-saving pushing the material. Generally, when the material to be processed is soft, choose a larger rake angle, otherwise, choose a smaller rake angle.
The angle of the serration is the position of the serration during cutting. The angle of the serration affects the cutting performance. The biggest influence on cutting is the rake angle γ, the relief angle α, and the wedge angle β. The rake angle γ is the cutting angle of the saw tooth. The larger the rake angle, the lighter the cutting. The rake angle is generally between 10-15°C. The clearance angle is the included angle between the saw tooth and the machined surface. Its function is to prevent the saw tooth from rubbing against the machined surface. The larger the clearance angle, the smaller the friction and the smoother the processed product. The clearance angle of cemented carbide saw blades is generally 15°C. The wedge angle is derived from the front and back angles. But the wedge angle cannot be too small, it plays a role in maintaining the strength, heat dissipation and durability of the saw tooth. The sum of the rake angle γ, the rear angle α, and the wedge angle β is equal to 90°C.
 In the manufacture of cemented carbide saw blades, generally not so many specifications of saw blades are made. According to the optimization rules and according to the current wood processing enterprises' equipment, materials and other specific factors, it is composed of the currently commonly used carbide saw blade specifications. This is not only conducive to our choice of carbide saw blades, but also conducive to the large-scale production of alloy saw blade manufacturers.
Under normal circumstances, the right and left teeth should be selected for sawing particleboard and medium-density boards, flat ladder teeth (flat teeth, trapezoidal teeth combination) should be selected for sawing veneer panels and fireproof boards. The outer diameter of the saw blade is mostly Ф300-350mm according to different circular saw models, and the thickness of the saw blade is related to the diameter. Ф250-300mm thickness 3.2mm, Ф350mm above 3.5mm.
Due to the large cutting rate of the computer cutting saw, the diameter and thickness of the carbide saw blade used are relatively large, the diameter is about 350-450mm, and the thickness is between 4.0-4.8mm. Most of them use flat stepped teeth to reduce edge chipping. , Saw marks.
The alloy saw blades for sawing wood usually use the left and right tooth shape combined by the teeth, because this combination has a large rake angle, which can sharply cut the wood fiber structure and make the cut smooth. For slotting that needs to keep the bottom of the slot flat, use a flat tooth profile or a combination of left and right flat teeth.   

 (4) Precautions before using the saw blade
1. The machine is in good condition, the spindle has no deformation or vibration, the shaft diameter tolerance is h7, and a protective cover should be installed when using it;
2. The operator should have the necessary knowledge for the operation and be equipped with protective eyepieces, pay attention to ties and cuffs, no gloves, and a work cap for long hair;
3. Check whether the saw teeth are missing, falling off, abnormal wear, and saw disc bending, twisting, cracking and other abnormal phenomena;
 4. When installing, ensure that the rotation direction of the saw blade is consistent with the rotation direction of the machine spindle;
5. When installing, confirm that the selected saw blade is suitable for the speed and feed of the material to be cut (according to the recommendation in the text, first select the cutting speed and feed per tooth, and then calculate the speed and feed per minute according to the number of teeth of the saw blade diameter
6. Every time you install the flange, you must ensure that the surface of the flange is flat and clean, parallel to each other and perpendicular to the axis, the size should be the same, the minimum diameter of the flange is 1/3 of the diameter of the saw blade, and the gasket should be vertical;
7. When installing, the saw blade should be higher than the height of the plate at least equal to the height of the saw tooth;
8. When cross-cutting, the teeth to be cut at the same time are at least 3 teeth, otherwise the saw blade will swing;
9. The material to be cut should be fixed when in use. If the sound and vibration are abnormal, the cut surface is rough or bent, the operation should be stopped, timely inspection, and troubleshooting.
10. When the saw blade is not sharp and the cut surface is rough, it must be re-grinded in time, and the original angle cannot be changed during re-grinding, and it must be re-grinded by a reliable professional manufacturer;
11. During the packaging and unpacking operations of the circular saw blade (such as the packaging machine), you must be very careful, and the sharp blade can easily cause damage;
12. When handling saw blades, proper packaging must be used to avoid damage. 

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