Metal plate high-temperature friction coefficient testing system and calculation method thereof

Abstract

The invention discloses a system for testing the high-temperature friction coefficient of a metal plate. The friction clamp assembly is mounted on the rack assembly and comprises two friction units which are oppositely arranged to apply positive pressure to a sample, and a bearing assembly which can operably move at least one friction unit in the clamping direction; one of the two friction units is movably and adaptively connected with the bearing assembly; the guiding and fixing assembly is fixedly connected to the rack assembly, located below the friction clamp assembly and used for guiding stretching movement of the sample; the conductive heating assembly is used for conducting and heating the sample and is electrically connected with a conductive clamping end used for clamping the sample; the stretching device is used for stretching the sample in the length direction of the sample and is provided with a stretching clamping end for clamping the sample.

Description

technical field [0001] The invention relates to the technical field of testing machines and precision instruments, in particular to a high-temperature friction coefficient testing system for metal plates and a calculation method thereof. Background technique [0002] The hot forming process has significant advantages in improving sheet formability, reducing forming force and improving the accuracy of formed parts, and it is more and more widely used in automotive, aerospace and other fields. Compared with cold forming, the friction behavior between the sheet metal and the forming die is more complex in hot forming, which has a huge impact on the forming accuracy, surface quality of the part and the friction and wear of the die. In order to accurately describe the friction behavior between the sheet metal and the die during the hot stamping process, it is necessary to accurately measure the friction coefficient of the sheet material under different temperature, contact pressu...

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Problems solved by technology

[0003] However, the temperature difference between the sheet metal and the mold is large during the thermoforming process, and there is a strong heat exchange, especially for thin sheets with a thickness of less than 1mm, the temperature of the sheet metal changes drastically, and the current experimental device for measuring the friction coefficient is in the process of experiment and calculation. The impact of the dynamic change of the sheet metal during the contact process on the measurement of the friction coefficient is not considered and there is no corresponding friction coefficient data processing method

[0004] The patent "CN202122370719.2" provides a testing machine capable of simulating different usage situations and testing the friction coefficient of products multiple times under different angles, which solves the problems of the traditional friction coefficient testing machine with a single function and poor measurement accuracy, but this testing machine cannot achieve The function of heating and temperature control of the measured object

[0005] The patent "CN112798454A" realizes the measurement of the friction coefficient of the tested sheet metal at a set temperature, but this method uses a heating furnace to heat, which is different from the conductive heating method when the plate is actually formed, which will lead to differences in the friction surface state of the sheet metal. In turn, it affects the measurement accuracy, and does not take into account the temperature drop when the plate is in contact with the mold, and the temperature of the actual friction area of ​​the plate cannot be obtained

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