Model Representation Method of Woodworking Alloy Saw Blades
Carbide saw blades are the most commonly used cutting tools for wood product processing. The quality of carbide saw blades is closely related to the quality of processed products. The correct and reasonable selection of carbide saw blades is of great significance to improving product quality, shortening the processing cycle, and reducing processing costs.
Carbide saw blades include many parameters such as alloy cutter head type, base material, diameter, number of teeth, thickness, tooth shape, angle, aperture, etc. These parameters determine the processing capability and cutting performance of the saw blade. saw blade.
When choosing a saw blade, you need to choose the correct saw blade based on the type of material you are cutting, thickness, sawing speed, sawing direction, feed speed and sawing width.
1. Selection of carbide saw blades
(1) Selection of cemented carbide types
Commonly used types of cemented carbide are tungsten cobalt (code YG) and tungsten titanium (code YT). Because tungsten and cobalt carbides have good impact resistance, they are more widely used in the wood processing industry. Commonly used models for wood processing include 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 increase, but the hardness and wear resistance decrease. Choose according to actual situation.
(2)Selection of base material
1. 65Mn spring steel has good elasticity and plasticity, economical material, good heat treatment hardenability, low heating temperature, easy to deform, and can be used for saw blades with low cutting requirements.
2. Carbon tool steel has high carbon content and high thermal conductivity, but its hardness and wear resistance drop sharply at temperatures of 200°C to 250°C. It has large heat treatment deformation, poor hardenability, long tempering time, and is prone to cracking. Economical material for manufacturing T8A, T10A, T12A and other cutting tools.
3. Compared with carbon tool steel, alloy tool steel has better heat resistance, wear resistance and better control performance. Thermal deformation temperature is 300℃-400℃, suitable for manufacturing high-grade alloy circular saw blades.
4. High-speed tool steel has good hardenability, strong hardness and rigidity, and small heat-resistant deformation. It is a thermoplastically stable ultra-high-strength steel suitable for manufacturing high-end ultra-thin saw blades.
(3)Selection of diameter
The diameter of the saw blade is related to the sawing equipment used and the thickness of the workpiece being sawed. The smaller the diameter of the saw blade, the lower the cutting speed; the larger the diameter of the saw blade, the higher the requirements for the saw blade and sawing equipment, and the higher the sawing efficiency. The outer diameter of the saw blade is selected according to different circular saw models, and saw blades of the same diameter are used.
Standard parts diameters are: 110MM (4 inches), 150MM (6 inches), 180MM (7 inches), 200MM (8 inches), 230MM (9 inches), 250MM (10 inches), 300MM (12 inches), 350MM (14 inches), 400MM (16 inches), 450MM (18 inches), 500MM (20 inches), etc. The bottom groove saw blade of precision panel saw is mostly designed to be 120MM.
(4) Selection of number of teeth
Generally speaking, the greater the number of teeth, the more cutting edges that can be cut per unit time and the better the cutting performance. But the more cutting teeth, the more carbide is needed. The price of the saw blade is high, but the teeth are too dense. , the amount of chips between teeth becomes smaller, which can easily cause the saw blade to heat up; in addition, there are too many saw teeth, and if the feed rate is not matched properly, the cutting amount of each tooth will be very small, which will intensify the friction between the cutting edge and the workpiece, affecting the use of cutting. life. edge. . Usually the tooth pitch is 15-25mm, and a reasonable number of teeth should be selected according to the sawing material.
(5)Selection of thickness
The thickness of the saw blade: In theory, we hope that the saw blade is as thin as possible, and the saw kerf is actually a kind of consumption. The material of the alloy saw blade base and the manufacturing process of the saw blade determine the thickness of the saw blade. If the thickness is too thin, the saw blade will easily shake during operation, affecting the cutting effect. When choosing a saw blade thickness, consider the stability of the blade and the material being cut. The thickness required for some special-purpose materials is also specific and should be used according to the requirements of the equipment, such as grooving saw blades, scribing saw blades, etc.
(6) Selection of tooth shape
Commonly used tooth shapes include left and right teeth (alternating teeth), flat teeth, trapezoidal flat teeth (high and low teeth), inverted trapezoidal teeth (inverted conical teeth), dovetail teeth (hump teeth), and the rare industrial grade three. Left and right, left and right, left and right, flat teeth, etc.
1. The left and right teeth are the most widely used, with fast cutting speed and relatively simple grinding. Suitable for cutting and cross-sawing various soft and hard solid wood profiles and density boards, multi-layer boards, particleboards, etc. The left and right teeth are equipped with anti-rebound protection teeth called dovetail teeth, which are suitable for longitudinal sawing. Use tree knots to cut various wood boards; the left and right tooth saw blades with negative rake angles are mostly used for pasting due to their sharp teeth and good sawing quality. Sawing of panels.
2. The flat-tooth saw has a rough cutting edge, slow cutting speed, and is the easiest to sharpen. Mainly used for sawing ordinary wood, with low cost. It is mostly used for aluminum saw blades with smaller diameters to reduce adhesion during cutting, or for grooving saw blades to keep the groove bottom flat.
3. Trapezoidal flat teeth are a combination of trapezoidal teeth and flat teeth. The grinding process is more complicated. When sawing, it can reduce the cracking of veneer. Suitable for sawing various single and double-veneered artificial boards and fireproof boards. In order to prevent aluminum saw blades from sticking, saw blades with more flat teeth are often used.
4. Inverted ladder teeth are often used in the bottom groove saw blade of panel saws. When sawing double-veneer artificial boards, the groove saw adjusts the thickness to complete the groove process on the bottom surface, and then the main saw completes the sawing process of the board, which can prevent the saw edge from chipping.
To sum up, when sawing solid wood, particle board, and medium density board, you should use left and right teeth, which can sharply cut the wood fiber structure and make the cut smooth; in order to keep the groove bottom flat, you can use flat teeth or left and right teeth. Combination teeth; When sawing veneers and fireproof boards, ladder-flat teeth are generally used. Due to the large sawing rate, the diameter and thickness of the alloy saw blades used in computer sizing saws are relatively large, with a diameter of about 350-450mm and a thickness between 4.0-4.8mm. Most of them are flat teeth. Used to reduce chipping and saw marks.
(7)Selection of sawtooth angle
The angle parameters of the sawtooth part are relatively complex and the most professional. 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 rake angle, relief angle and wedge angle.
The rake angle mainly affects the force expended in sawing the wood blade. The larger the rake angle, the sharper the saw tooth cutting, the lighter the sawing, and the easier it is to push the material. Generally speaking, when the material to be processed is soft, a larger rake angle is used; otherwise, a smaller rake angle is used.
The angle of the saw teeth is the position of the saw teeth when cutting. The angle of the saw teeth affects cutting performance. The factors that have the greatest impact on cutting are rake angle γ, clearance angle α, and wedge angle β. The rake angle γ is the cutting angle of the saw teeth. The larger the rake angle, the faster the cutting speed. The rake angle is generally between 10-15°C.
The relief angle is the angle between the saw teeth and the machined surface. Its function is to prevent friction between the saw teeth and the processing surface. The larger the clearance angle, the smaller the friction and the smoother the processed product.
The clearance angle of carbide saw blades is generally 15°C. The wedge angle is derived from the front and back angles. However, the wedge angle should not be too small. It plays a role in maintaining the strength, heat dissipation and durability of the teeth. The sum of rake angle γ, relief angle α and wedge angle β is equal to 90°C.
(8) Selection of aperture
The aperture is a relatively simple parameter, which is mainly selected according to the requirements of the equipment. However, in order to maintain the stability of the saw blade, it is best to use a larger aperture for saw blades above 250MM.
At present, the hole diameters of standard parts designed in China are mostly 20MM holes of 120MM and below, 25.4MM holes of 120-230MM diameter, and 30 holes of 250mm and above. Some imported equipment also has 15.875MM holes, and the mechanical aperture of multi-blade saws is relatively complex. , and also equipped with keyway to ensure stability.
Regardless of the hole diameter, it can be modified with a lathe or wire cutter. Lathes can turn large holes, and wire cutting machines can ream holes according to equipment requirements.
A series of parameters such as the type of alloy cutter head, base material, diameter, number of teeth, thickness, tooth shape, angle, aperture, etc. are combined into the entire carbide saw blade. Only reasonable selection and matching can better utilize its advantages.