1.The hardness of the blade material and heat treatment
Usually the matrix material 65Mn steel, heat treatment hardness 38-42HRC, since the head of domestic quality, the quality of welding and heat treatment affect the quality, the general control 35-40HRC.
Segment YG8 general use, the blade is typically used YG8A abroad and YG8X, YG8A carbide for high-quality, superior performance YG8, YG8X with respect YG8 organization finer grain, red hot toughness, durable, long life, in the process of cutting friction heat has little effect, but the disadvantage of higher costs, the average tooth about twice as expensive. Segment hardness greater than HRA90.
2.Grinding head angle
There are four main angle is more important:
Rake angle:
According to foreign and sample blade, saw blade angle saw timber before the general control of 15-20 °. Principles approached the greater the angle the more sharp, but the shorter the tool life, easy to chipping; due to different cutting material, rake angle is also quite different, cutting harder the material, the greater the relative cutting resistance should be small rake angle, even negative rake angle. Also saw blade rake angle of 25 ° to the saw blade, the saw blade on the use of DeWalt DC rake angle 22 °, the main analysis because DC power is small, the output torque, so the use of a large rake angle, the tool sharp reduction small cutting resistance.
After the horn:
According to foreign and sample blade, saw blade angle saw timber generally controlled 12-15 °, after the angle is too small, the tip increase friction with the timber, the impact of the use of the saw blade; rear angle should not be too large, too much strength tool reduce, reduce service life.
Edge inclination:
The main impact of the chip flow direction, increasing sharpness, but the blade angle over the General Assembly to reduce the strength of the tip, the blade, and therefore according to the foreign samples, select the range of saw blade angle 8-10 °.
Main angle (tooth angle points):
Increasing the lead angle in favor of chip discharge, reduced friction, but too much will reduce the strength of the tool, resulting in reduced life expectancy. This angle is generally taken 10-12 °.
The other two vice declination, mainly in favor of chip, reducing friction. This angle generally take 2-3 °.
3.Processing
The original process:Blanking molding ---- ----- take stress matrix hardening and tempering (plastic) ------ ----- mill hinge bore welding plane ----- ----- teeth grinding tooth sandblasting ----- ----- printing
Online process: blanking molding ---- ----- Stress relief annealing the substrate tempering (plastic) ------ ----- mill hinge bore welding flat tooth --- ----- - grinding teeth grinding ----- ------ ----- blasting printing.
After the original process grinding sandblasting, cutting edge and the blade sharp edge passivation, affecting the sharpness of the blade, increasing the sandblasting process after grinding, so keep the blade sharp, extended service life.
4.Others
Substrate thickness with tooth thickness should maintain a certain relationship, generally tooth thickness should be larger than the substrate thickness of about 0.8-1mm. Guarantee not to rub the base when the saw blade to use.
The matrix itself posterior horn, usually large angle than the rear tip of about 2 °, mainly in order to ensure the blade to maintain a certain amount of feed at the time of use, not because of human factors, leading to excessive feeding, which leads to chipping or tools stall burn. Shaped charges DeWalt DC saw blade, as shown, the main role is to ensure a certain amount of feed, at the same time play the role of Chip.
Cutter runout, so ensure continuous balance cutting a more important factor, currently requires runout less than 0.1mm.
Saw static balance must also be controlled, static balance is too large, will lead the blade to vibrate at high speed cutting process, this index saw a slight change in accordance with the specifications.
5.Elastic Modulus
For the same material, in different conditions of hardness, modulus of elasticity vary, generally the elastic modulus increases with the hardness, with the amount of deformation of the elastic modulus increases.
When the matrix hardness, the amount of deformation becomes small. The blade during the cutting process should maintain a certain amount of deformation, deformation excessive kerf becomes large, resulting in wasted effort increases, the deformation is too small, will cause friction at the same time a plurality of jagged wood, increasing the friction force.
There is a balance between the power output of the tool for sawing wood for power = + friction as wasted effort; we want to make friction wasted effort as possible. Therefore, the amount of deformation must ensure that within an appropriate range, both to ensure the kerf width, and reduced friction.
That should ensure a certain matrix hardness, currently used as a matrix hardness HRC35-40, mainly to ensure the elastic modulus to ensure deformation. Due to the presence of the main angle, so that the cutting force of the blade to produce vertical force component, so that working head is deformed, the other did not work does not rub the tip of the workpiece (timber)
