CN-117733648-B - Cutting temperature testing method and system adopting sheet insulating thermocouple

Abstract

The invention provides a cutting temperature testing method and a system adopting a flake insulating thermocouple, wherein the testing system comprises a workpiece, a thermocouple, a wire, a thermocouple temperature measuring acquisition card and a cutting tool; and when the workpiece is processed, the workpiece material and the metal sheet are subjected to plastic deformation, and the first metal sheet and the second metal sheet are bonded together to form a temperature measuring node. According to the invention, the insulating film is deposited on the periphery of the metal sheet to prepare the sheet insulating thermocouple, so that the insulating reliability of the thermocouple is improved, and the two metal sheets are bonded together under the plastic deformation action to form a temperature measuring node, so that the grinding temperature measuring stability and sensitivity are improved.

Inventors

• HOU ZHIBAO
• YAO ZHENQIANG
• DU HAIFENG
• TANG ZHENRONG

Assignees

• 上海交通大学

Dates

Publication Date

20260512

Application Date

20240112

Claims (10)

1. 1. A method for testing cutting temperature using a thin-sheet insulated thermocouple, the method comprising the steps of: Step S1, selecting a metal sheet thermocouple, and polishing four sides of a first metal sheet and a second metal sheet of the thermocouple; Step S2, plating a layer of insulating film on four sides of the first metal sheet and the second metal sheet in a film deposition mode; S3, respectively connecting the coated first metal sheet and the coated second metal sheet serving as the positive electrode and the negative electrode of the thermocouple with a thermocouple temperature measurement acquisition card through wires; S4, cutting the workpiece into a first workpiece and a second workpiece, attaching the coated first metal sheet and the coated second metal sheet in parallel, clamping the first metal sheet and the second metal sheet of the thermocouple by the first workpiece and the second workpiece, enabling the metal sheets to be perpendicular to the machining direction of the workpiece and protrude out of the machining surface of the workpiece, and insulating the first metal sheet, the second metal sheet and the workpiece by an insulating film; S5, when a workpiece is machined, a cutting tool cuts off a thermocouple metal sheet protruding from the upper surface of the workpiece and a workpiece material, the workpiece material and the metal sheet are subjected to plastic deformation under the action of the cutting tool, the first metal sheet and the second metal sheet are bonded together to form temperature measuring nodes, and a thermocouple temperature measuring acquisition card measures potential difference between the metal nodes to obtain a temperature value of a workpiece machining area; the thickness of the first metal sheet and the second metal sheet is 10 mu m-200 mu m, and the width is 1mm-5mm; The thickness of the insulating film is 0.1 μm to 1.5 μm.
2. 2. The method for testing the cutting temperature of the thin-sheet insulated thermocouple according to claim 1, wherein the materials of the first metal thin sheet and the second metal thin sheet in the step S1 meet the international standard of IEC, and the graduation numbers and the materials are S-type platinum rhodium-pure platinum, R-type platinum rhodium-pure platinum, B-type platinum rhodium-platinum rhodium, K-type nickel chromium-nickel silicon, T-type pure copper-copper nickel, J-type iron-copper nickel, N-type nickel chromium silicon-nickel silicon, E-type nickel chromium-copper nickel.
3. 3. The method for testing the cutting temperature of the thin-sheet insulated thermocouple according to claim 1, wherein the thin film deposition in the step S2 is chemical vapor deposition or physical vapor deposition; the insulating film is a ceramic oxide or a metal oxide having insulating properties.
4. 4. The method for testing the cutting temperature of the thin-sheet insulated thermocouple according to claim 1, wherein the insulating film in the step S2 is made of silicon dioxide, aluminum oxide or titanium dioxide.
5. 5. The method for testing the cutting temperature of the thin-sheet insulated thermocouple according to claim 1, wherein a cuboid area extending from the processing surface of the workpiece to the bottom surface of the workpiece is formed after the first workpiece and the second workpiece are attached in the step S4, the thin-sheet thermocouple is placed on the surface of the workpiece, the length of the rectangular extending area of the surface of the workpiece is not less than the width of the metal thin sheet, and the width of the rectangular extending area is not greater than the thickness of the coated first metal thin sheet and the coated second metal thin sheet after being attached.
6. 6. A cutting temperature testing system employing a thin-sheet insulated thermocouple, the system comprising the following modules: the module M1 is characterized in that a metal sheet thermocouple is selected, and four sides of a first metal sheet and a second metal sheet of the thermocouple are polished; A module M2, plating a layer of insulating film on four sides of the first metal sheet and the second metal sheet in a film deposition mode; the module M3 is used for respectively connecting the first metal sheet and the second metal sheet which are coated with films as the positive electrode and the negative electrode of the thermocouple with the thermocouple temperature measurement acquisition card through wires; cutting the workpiece into a first workpiece and a second workpiece, attaching the coated first metal sheet and the coated second metal sheet in parallel, clamping the first metal sheet and the second metal sheet of the thermocouple by the first workpiece and the second workpiece, enabling the metal sheets to be perpendicular to the machining direction of the workpiece and protrude out of the machining surface of the workpiece, and insulating the first metal sheet, the second metal sheet and the workpiece by an insulating film; When a workpiece is machined, a cutting tool cuts off the thermocouple metal sheets protruding from the upper surface of the workpiece and the workpiece material, the workpiece material and the metal sheets are subjected to plastic deformation under the action of the cutting tool, the first metal sheets and the second metal sheets are bonded together to form temperature measuring nodes, and a thermocouple temperature measuring acquisition card measures potential differences between the metal nodes to obtain a temperature value of a workpiece machining area; the thickness of the first metal sheet and the second metal sheet is 10 mu m-200 mu m, and the width is 1mm-5mm; The thickness of the insulating film is 0.1 μm to 1.5 μm.
7. 7. The cutting temperature test system using the thin-sheet insulated thermocouple according to claim 6, wherein the materials of the first metal thin sheet and the second metal thin sheet in the module M1 conform to the international standard of IEC, and the index numbers and the materials are S-type platinum rhodium-pure platinum, R-type platinum rhodium-pure platinum, B-type platinum rhodium-platinum rhodium, K-type nickel chromium-nickel silicon, T-type pure copper-copper nickel, J-type iron-copper nickel, N-type nickel chromium silicon-nickel silicon, E-type nickel chromium-copper nickel.
8. 8. The cutting temperature test system using a thin-sheet insulated thermocouple according to claim 6, wherein the thin film deposition mode in the module M2 is chemical vapor deposition or physical vapor deposition; the insulating film is a ceramic oxide or a metal oxide having insulating properties.
9. 9. The cutting temperature test system using the thin-sheet insulated thermocouple according to claim 6, wherein the insulating film in the module M2 is made of silicon dioxide, aluminum oxide or titanium dioxide.
10. 10. The cutting temperature test system using the thin-sheet insulated thermocouple according to claim 6, wherein a rectangular area extending from the processing surface of the workpiece to the bottom surface of the workpiece is formed after the first workpiece and the second workpiece in the module M4 are attached, for placing the thin-sheet thermocouple, the length of the rectangular extending area on the surface of the workpiece is not less than the width of the metal sheet, and the width of the rectangular extending area is not greater than the thickness of the coated first metal sheet and the coated second metal sheet after being attached.

Description

Cutting temperature testing method and system adopting sheet insulating thermocouple Technical Field The invention relates to the technical field of cutting processing, in particular to a cutting temperature testing method and system adopting a thin-sheet insulating thermocouple. Background Milling and grinding are effective machining modes for removing materials, and play an important role in the field of cutting machining, in the machining process, a workpiece is fixed on a displacement platform of a machine tool, a milling cutter or a grinding wheel is used as a cutter, the workpiece material is rotationally cut at a high speed, and the temperature of the surface of the workpiece can reach hundreds of degrees centigrade. The temperature is an important factor influencing the processing quality of the surface of the workpiece, and too high temperature can cause burn on the surface of the workpiece, so that the strength of the workpiece is reduced. Measuring the temperature of the machined surface is of great importance for assessing the quality of the machining and improving the performance of the workpiece. During milling or grinding, the temperature is typically measured using a thermal infrared imager or a contact thermocouple. The thermal infrared imager can measure the temperature of a region, has large temperature measuring area, is easy to be blocked by cutting fluid, and causes inaccurate temperature measurement. The thermocouple is composed of two different metals, wires are connected at a temperature measuring node, different potential differences are formed by the thermocouple at different temperatures, and the potential difference between two poles of the thermocouple is measured, so that a temperature value can be obtained. In order to achieve the cutting temperature measurement effect, a thermocouple wire is generally clamped by 2 workpieces, the thermocouple wire protrudes out of the workpieces, the wire protruding out of the workpieces is cut off under the action of a grinding wheel or a milling cutter, and the workpieces are plastically deformed and bonded with the wire to form a temperature measurement node. Besides the temperature measuring nodes, the thermocouple wires are required to be insulated, and the thermocouple wires and the workpiece are insulated from each other through mica sheets. The thermocouple clamping mode can measure the temperature value of the surface of the cut workpiece, but the temperature measuring node is formed by plastic deformation of the metal wire, so that the temperature measuring node is unstable, cutting fluid easily permeates into a gap between the thermocouple metal wire and the workpiece, and the insulation performance of a thermocouple measuring loop is damaged, so that the temperature measurement is failed. Therefore, in order to improve the cutting temperature test effect, a method for measuring the temperature of the surface of the cutting workpiece with high stability and high precision needs to be researched. Therefore, a new technical solution needs to be proposed. Disclosure of Invention Aiming at the defects in the prior art, the invention aims to provide a cutting temperature testing method and system adopting a thin-sheet insulating thermocouple. According to the cutting temperature testing method adopting the thin-sheet insulated thermocouple provided by the invention, the method comprises the following steps of: Step S1, selecting a metal sheet thermocouple, and polishing four sides of a first metal sheet and a second metal sheet of the thermocouple; Step S2, plating a layer of insulating film on four sides of the first metal sheet and the second metal sheet in a film deposition mode; S3, respectively connecting the coated first metal sheet and the coated second metal sheet serving as the positive electrode and the negative electrode of the thermocouple with a thermocouple temperature measurement acquisition card through wires; S4, cutting the workpiece into a first workpiece and a second workpiece, attaching the coated first metal sheet and the coated second metal sheet in parallel, clamping the first metal sheet and the second metal sheet of the thermocouple by the first workpiece and the second workpiece, enabling the metal sheets to be perpendicular to the machining direction of the workpiece and protrude out of the machining surface of the workpiece, and insulating the first metal sheet, the second metal sheet and the workpiece by an insulating film; and S5, when the workpiece is machined, the cutting tool cuts off the thermocouple metal sheet protruding from the upper surface of the workpiece and the workpiece material, the workpiece material and the metal sheet are subjected to plastic deformation under the action of the cutting tool, the first metal sheet and the second metal sheet are adhered together to form a temperature measuring node, and the thermocouple temperature measuring acquisition card measures the potential differen