The Temperature Of Circular Saw Blade On-line Detection And Control Technology Research In Woodiness Material Cutting

Saw processing is one of the most common way in wood processing. In the cutting process of wood, circular saws are most used especially for the plantation timber. It has been recognized as the most effective ways to improve the utilization of wood and reduction the loss of processing that reduce the thickness of the saw blade, increase its stability and reduce the loss of the wood saw processing. During the process of circular saw blade cutting, a large amount of heat will generate because of the friction of high speed rotating saws and workpieces. This article uses the Raytek MI3 infrared thermometer to measure the different point at the surface of the saw when it is cutting the different woods which include the MDF, the padouk, the pine and the reconsolidated bamboo.The paper also discussed the temperature change of the different point at the suface of the saw blade and the analyses of the instability of the saw combined with the theory of heat transmission. The paper designed a wood sawing coolant cooling system and introduced its system structure, working principle, main technical parameters and the system design. Besides, ANSYS Fluent software is used to simulate the internal flow field of nozzle which designed in the paper. This paper studies the conclusions as follows:(1) This paper analyzed the factors which influence the circular saw blade from the theoretical analysis and calculation of heat conduction, convection and radiation of the circular saw. The thermal stress and centrifugal stress on the saw blade are analyzed in theory, heat conduction and thermal convection influence on the temperature field of circular saw blade, and the thermal radiation have little impact on temperature field. The paper calculate the circular saw blade on a bit thermal stress components and the mathematical expressions of radial and tangential stress, the maximum radial and tangential stress are also deduced. In the theoretical analysis of heat conduction and thermal radiation, the corresponding mathematical model is given, and the general expression are also soluted.(2) This paper uses the K type thermocouple and infrared thermometer under the same condition to measure the temperature change of the same point on saw blade, which aims to calibrate the emittance of infrared thermometer. The emittance of the surface of metal circular saw blade is obtained by look-up table, and insure the general scope of the emissivity and then by changing the infrared measuring temperature probe the value of the emissivity under different emittance comparing K type thermocouple thermometer and temperature of the curve. From the result of the experiment, when set the emissivity at 0.3, infrared thermometer to measure temperature change curve of saw blades and thermocouple measured blade curve of temperature changing with time are consistent best.(3)Experiment shows that in the process of sawing the temperature of sawtooth and the edge of the saw body change obviously, the sawtooth has the largest temperature rise, from the edge of the saw body to the edge of the chuck, the temperature rise decrease. The edge of the chuck showed little change in temperature. In the conditions of the feed speed at 6m/min, the temperature disparity up to the maximum of 56.3 when sawing the reconsolidated bamboo. The thickness of sawing three different kind of wood is very small under the feed speed of 6m/min, and in the range of normal processing.(4) The paper uses a new wood sawing coolant cooling spray system for the circular saw blade of on-line cooling group which can effectively reduce the working temperature of the circular saw blade in sawing process. Slit type nozzle jet atomization of water cold air to form a approximate sectorial domain, the cooling medium can be concentrated in the circular saw blade set of effective working area, which can reduce the waste of cooling medium, so that the service life of the circular saw blade group and wood sawing processing quality can significantly improved.(5) The article uses the ANSYS Fluent software to analysis the internal fluid situation of spray system work condition and simulate the nozzle of mixing chamber pressure distribution, the velocity distribution within the cooling medium, calculate the nozzle outlet flow of 0.009kg/s. Under the condition of 1MP pressure, 132m/s value of velocity and 0.009kg/s flow, the cooling medium can atomize into fine particles which prove the rationality of the structure design of the cooling nozzle.