Wireless temperature measuring system and method for carbon fiber composite drilling

Abstract

The invention belongs to the field of mechanical detection, and relates to a wireless temperature measuring system and method for carbon fiber composite drilling. The system comprises a wireless temperature measuring tool handle unit, a man-machine interaction parameter setting and measuring result displaying unit and a wireless signal receiving unit connected with the man-machine interaction parameter setting and measuring result displaying unit. The temperature measuring method comprises the steps that the wireless temperature measuring tool handle unit is assembled at first; the installed wireless temperature measuring tool handle unit is connected with a machine tool spindle, the sampling frequency is set, required technological parameters are set, and a machine tool is started; and an A / D conversion chip of a wireless signal transmitting unit conducts data collection on weak electric signals converted by a thermocouple. According to the wireless temperature measuring system and method, no damage is caused to the machine tool spindle, no special workpiece is needed, and all data of transient temperature changes in the whole carbon fiber composite drilling process on any technological conditions can be obtained. The temperature measuring system is simple and reliable. According to the temperature measuring method, the test cycle is shortened, and the test cost is lowered.

Description

technical field [0001] The invention belongs to the field of mechanical detection and relates to a wireless temperature measurement system and method for drilling carbon fiber composite materials. Background technique [0002] Carbon fiber composite materials have many advantages such as light weight, high strength, corrosion resistance, etc., can greatly improve payload and fuel consumption, and have been widely used in aerospace, automobiles, ships and other fields. However, since the components of carbon fiber composite materials cannot be connected by welding, mechanical connection using bolts has become the only option in the assembly process of carbon fiber composite materials. In order to meet the dimensional accuracy requirements of connection assembly, cutting of carbon fiber composite parts is one of the indispensable links in the manufacturing process of carbon fiber composite materials. Drilling is the most important cutting processing form of carbon fiber compo...

AI Technical Summary

Problems solved by technology

Non-contact temperature measurement technology such as infrared thermal imaging technology, its working principle is to use the detector to measure the infrared difference between the target itself and the background to obtain different infrared images. However, due to the semi-closed characteristics of the drilling process, infrared The sensor probe of the thermal imager can only obtain the temperature field distribution at the drilling entrance and exit, and it is difficult to obtain the temperature change during the drilling process

[0003] Most of the research on the drilling temperature of composite materials adopts the method of artificial thermocouple. According to research, this method needs to open a hole in the composite material workpiece to place the thermocouple. Usually, the diameter of the hole is much larger than the wire diameter of the thermocouple. Accuracy of Measurement Results

Moreover, the most important thing is that this method can only obtain the change law of the temperature at the specified point with time, and cannot capture the moment of temperature change during the entire drilling process, which has a great impact on the impact of cutting heat on the formation of machining damage and tool wear during the drilling process. In-depth analysis is crucial

In order to avoid the influence of workpiece embedded thermocouples on drilling temperature, in 2014, Tu Junxiang and others proposed the method of using a tool to fix the workpiece rotation in the article "Research on Temperature Measurement of Drill Bits for High-speed Drilling Carbon Fiber Composite Materials" published in the "Journal of Fuzhou University". method to measure the drilling temperature, the thermocouple is installed in the drill with internal cooling holes, the drill is fixed on the workbench through the three-jaw chuck, and the special cylindrical workpiece is installed on the machine tool spindle and moves together with the spindle, Although this method can obtain the signal of the instantaneous temperature change, and avoid the signal loss caused by the entanglement of the thermocouple signal wire during the tool rotation process, and even serious machine tool accidents, this method not only requires a special cylindrical carbon fiber composite material workpiece, but also requires The workpiece is clamped on the spindle of the machine tool. Due to the large amount of carbon fiber dust generated during the processing of carbon fiber composite materials, the dust is conductive. Once it enters the spindle, it will not only block the spindle, but also cause irreversible damage to the high-precision electrical components of the spindle of the machine tool. Thereby reducing the service life of the machine tool spindle, and eventually the test cannot be carried out normally

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