Variable frequency speed regulation device for vacuum carburizing process and speed regulating method thereof

Abstract

The invention discloses a variable frequency speed regulation device for a vacuum carburizing process and a speed regulating method thereof. The variable frequency speed regulation device comprises avacuum carburizing furnace and a plurality of radiant tubes, and further comprises a variable frequency speed regulation fan, a first thermocouple, a second thermocouple, a third thermocouple, a firstheat conduction probe, a second heat conduction probe, a third heat conduction probe, a fourth thermocouple, a fifth thermocouple and a sixth thermocouple, wherein the first thermocouple, the secondthermocouple and the third thermocouple are respectively arranged at the centers above, on the side of and below a working area; the first heat conduction probe, the second heat conduction probe and the third heat conduction probe are arranged at the centers of the upper surface, the side surface, and the lower surface of the working area; the fourth thermocouple, the fifth thermocouple and the sixth thermocouple are arranged at the centers of the upper surface, the side surface, and the lower surface of a workpiece in the working area. According to the variable frequency speed regulation device for the vacuum carburizing process and the speed regulating method thereof, the flow rate and pressure of carburizing gas in the vacuum carburizing furnace and the rotating speed of the variable frequency speed regulation fan are adjusted by a computer control system, so that the rate of temperature rise, heat diffusion, and / or cooling of the workpiece in the deep cooling process can be controlled.

Description

technical field [0001] The invention relates to the technical field of vacuum carburizing, in particular to a frequency conversion speed regulating device and a speed regulating method for the vacuum carburizing process. Background technique [0002] The vacuum carburizing process is a pulsed process, that is, a process that alternates between the strong infiltration pulse stage and the diffusion stage. Fill the quenching furnace with carburizing agent in the strong infiltration stage, stop feeding the carburizing agent in the diffusion stage, and pump out the residual gas with low carbon atom content in the quenching furnace through the vacuum pump system to make the furnace reach the working vacuum degree. When the next pulse comes, fill in new carburizing agent for uniform carburizing. [0003] Existing vacuum carburizing and quenching furnaces are generally equipped with stirring fans, the purpose of which is to generate convection in the furnace and even the atmosphere...

AI Technical Summary

Problems solved by technology

However, the existing fan installed in the furnace does not have the function of speed regulation. The temperature control mode of the workpiece is controlled by the temperature signal measured by the thermocouple in the work area. The problem with this temperature control method is that the thermocouple is inserted. The position and the flow change of the gas in the furnace have a great influence on the measured temperature signal and the composition of the atmosphere, resulting in fluctuations, inaccuracies and hysteresis of the surface temperature and atmosphere of the workpiece, which seriously affects the carburization (nitriding) of the workpiece surface. Homogeneous and carburized layer depth

In addition, this control method is limited due to the fan speed adjustment, and the temperature of each part in the furnace and the inhomogeneity of the atmosphere flow cannot be accurately controlled by the fan speed, resulting in the surface of the workpiece in the process of carburizing or carbonitriding. Inhomogeneity of carbon, uniformity of carburized layer and carburized carbon black, etc.

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