Method and device for multi-point on-line detection of digital hydraulic machine column stress

Abstract

The invention discloses a method and a device for the multi-point on-line detection of digital hydraulic machine column stress. The device comprises a multiple column deformation detection mechanisms arranged on the hydraulic machine column, multiple digital contact type displacement sensors, a programmable logic controller and an upper computer, wherein each digital contact type displacement sensor corresponds to one column deformation detection mechanism; all the digital contact type displacement sensors is communicated with the programmable logic controller; the programmable logic controller is communicated with the upper computer; each column deformation detection mechanism comprises an upper anchor ear, a lower anchor ear, an upper bracket, a lower bracket and a displacement transmission rod; and the digital contact type displacement sensors are in contact with the free ends of the displacement transmission rods. The device has the advantages of strong interference rejection, high reliability, high measurement accuracy and high practicability.

Description

technical field [0001] The invention belongs to the technical field of machinery and electronics, and in particular relates to a multi-point online detection method and device for column stress of a digital hydraulic machine. Background technique [0002] The main body of the hydraulic press is generally composed of upper beams, movable beams, lower beams and columns. The column of the hydraulic press plays the role of supporting the body of the hydraulic press and guiding the movable beam, and bears the tensile load applied when the hydraulic press is pressurized. Under normal working conditions, the load borne by the column is within the allowable range of the design, but , once the operation error or the synchronous system of the hydraulic press fails, or there is a large eccentric load during processing, the movable beam may tilt greatly, which will generate a large lateral thrust on the column, and the column will bear additional stress. After the stress value exceeds ...

AI Technical Summary

Problems solved by technology

The strain gauge method uses the method of pasting the strain gauge on the surface of the column of the hydraulic press to detect the stress of the column, but the detection accuracy of the strain gauge itself is low, and it is easy to fall off, so it cannot be operated for a long time; The method is a method proposed considering that the strain gauge cannot be pasted on the surface of the hydraulic machine column for a long time, but this kind of sensor needs to be customized, and the accuracy and stability cannot be guaranteed. It is only a programmatic research; the vibrating wire method The vibrating wire sensor is used, the system structure is complex, it is not easy to install, and the ambient temperature has a great influence on the vibrating wire. A position-measuring detection method. This method has been used on 10,000-ton and 30,000-ton hydraulic presses, but it fails after running for a long time. The thermal stability and anti-interference ability of the eddy current sensor itself is poor, and it cannot be used for complex hydraulic machines. Even if the signal of the eddy current sensor is analog-to-digital converted and the method of dynamic zero point is adopted, the Achilles heel of the eddy current sensor cannot be changed - poor thermal stability

[0004] The detection components used in the above detection methods are all analog components. The detection accuracy of the analog components is low, poor stability, and weak anti-interference ability. However, the working environment of the hydraulic press is harsh, the humidity on site is high, the temperature fluctuates greatly, and the electromagnetic environment is complex. The signal transmitted on the computer is an analog signal, so the anti-interference ability of the whole system is poor, the detection accuracy is low, and the stability is poor. These methods cannot perform long-term reliable stress detection on the hydraulic press

In short, there is no practical multi-point online detection device for hydraulic press column stress.

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