Method and system for monitoring plastic deformation process and defects

Abstract

The invention provides a method and system for monitoring a plastic deformation process and defects. The method comprises the following steps of: a plurality of acceleration vibration sensors are mounted at positions of relative vibration displacements arising from the change of a forming force, on equipment or a die; the signal characteristics of the vibrations of the equipment and the die arising from the impact generated by deformation under a normal state is determined through acquiring signals from the sensors under normal circumstances and carrying out signal analysis; and when the working state of the die or the equipment changes, the signal characteristics of pressing vibration signals can also change, the correlation change between the signal characteristics and waveforms under a normal process state occurs, which can be recognized by using a digital correlation method, the system is led to control a pressing machine to carry out corresponding protective operation, and meanwhile, information on the defects is displayed on a display interface of the system. The system implementing the method mainly consists of the acceleration vibration sensors, a signal acquisition and storage device, a digital signal processor, a visible module and a control unit or a remote communication module.

Description

technical field [0001] The invention provides a method and system for monitoring the plastic deformation process and defects. The method and system describe the application of multi-dimensional sensors and signal acquisition and analysis methods, and use the digital correlation method to analyze the shock vibration response signal caused by the plastic deformation force. , to obtain the information for judging whether the working state of plastic deformation is normal or not. Background technique [0002] Plastic deformation is a complex dynamic process. The equipment drives the mold movement to cause the plastic deformation of the material (sheet or metal block). At the same time, the mold, equipment and workpiece will also produce a certain amount of elastic deformation. During the forming process, these elastic deformations accumulate The process, and these elastic deformations will be released after the molding is completed. Therefore, the corresponding vibration is cau...

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Problems solved by technology

Chinese patent 01810063.5 (method and system for on-line monitoring of stamping process) disclosed on July 6, 2003 an application method and system for measuring stamping force through strain sensors in stamping monitoring of open presses, international patent (WO 1992 007711 ) DIE CUSHION DEVICE OF PRESS MACHINE disclosed on May 14, 1992 a method and equipment for monitoring press action using hydraulic system pressure; international patent (WO2009078237) CONTROL DEVICE AND CONTROL METHOD FOR DIE-CUSHION DEVICE on June 2009 On March 25th, a method for monitoring the liquid flow rate of the hydraulic cylinder of the drawing pad for abnormal fluctuations was disclosed to realize the method of stamping quality monitoring; On September 5, 2000, a system that uses multiple acceleration sensors to monitor multi-station molds was disclosed, but it converts the acceleration signal into the displacement of the bottom dead point, and then converts the displacement of the bottom dead point to the sensitivity of the state of the equipment and the mold. As a monitoring signal, to judge the working state; U.S. Patent US006209400B2 (Portable press vibration severity monitoring system and method) disclosed a portable press vibration monitoring instrument and method of use on April 3, 2001. The monitoring system implemented by the hardware integrated circuit cannot adapt to the online monitoring of various process conditions; U.S. Patent US05724843A (Method of diagnosing pressing machine based on detected physical value as compared with reference) disclosed a method using A method for monitoring presses with various physical quantities, such as pressure, speed, load, temperature, etc., but does not involve vibration, especially multi-dimensional acceleration vibration signals; US Patent US06481295B1 (Method and system for monitoring peak compressive and tensile process severity levels of a press machine using acceleration data) in 2000 On October 18, a method for detecting the peak acceleration of a press was disclosed, which is used to determine the load capacity level of the press, rather than for monitoring, and the method only considers the peak; US Patent 04692857 (Method and apparatus for protecting press from being damaged by overload conditions) on September 8, 1987 disclosed a device and method for protecting the press from exceeding the allowable load curve by using a rotary encoder and hydraulic load; US Patent 05339665 (Die-cushion apparatus of press machine) was published in On August 23, 1994, a device that uses a hydraulic overload protection device to protect the mold from damage was disclosed; US Patent 006820026B1 (Console mounted vibration severity monitor) disclosed on January 19, 2000 a device that uses an acceleration sensor, a speed sensor and Displacement sensors are used to monitor the working status of the press, but this method only calculates its effective value (RMS), does not perform further signal processing on the signal waveform, and does not obtain characteristic values ​​related to the process or defects

In addition, there are other documents related to the description of press monitoring, but they are all theoretical research, and no effective means can be proposed for engineering practice.

Or monitor the oil, gas, liquid, electricity, machinery and other aspects of the press without taking into account the problem of forming process

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