CN-121977948-A - Drop hammer impact testing machine based on electromagnetic driving and resetting and control method thereof

CN121977948ACN 121977948 ACN121977948 ACN 121977948ACN-121977948-A

Abstract

The invention relates to the technical field of drop hammer impact testing machines, in particular to a drop hammer impact testing machine based on electromagnetic driving and resetting and a control method thereof. The non-contact electromagnetic acceleration thoroughly gets rid of the fatigue problem of the mechanical spring, and realizes an acceleration mode with high acceleration, high repeatability and infinite service life. By means of feedback type closed-loop control of the multi-stage coil, any preset impact speed can be accurately and repeatedly achieved. Acceleration, measurement, reset and circulation control are integrated into a whole, so that the full-automatic impact test of one-key operation is realized. The modular design enhances equipment adaptability and maintainability. The safety protection system guarantees stability of the test process. The invention can solve the technical problems of low accelerating capacity, large part loss, uncontrollable impact speed range and low reliability of the traditional drop hammer testing machine.

Inventors

HU QINGYI
QI TIANQI
LIAO CHENGTAO
AO XIN
WANG ZHANJUN
XIONG KUN
WANG XIAOMAO
DONG ZONGSHI
YU RUI

Assignees

长江勘测规划设计研究有限责任公司
武汉理工大学

Dates

Publication Date: 20260505
Application Date: 20260130

Claims (10)

1. Drop hammer impact testing machine based on electromagnetic drive and reset, characterized by comprising: The frame and the guide system are used for providing structural support and ensuring that the drop hammer moves along the vertical direction; the electromagnetic acceleration system comprises a plurality of stages of electromagnetic coils, wherein each stage of coils is independently connected with a capacitor group and a switch circuit and is used for applying electromagnetic thrust to the drop hammer; The electromagnetic lifting and resetting system comprises an electric control permanent magnet adsorption unit, realizes the adsorption and release of the drop hammer by switching the magnetic circuit state through pulse current, and is used for adsorbing and lifting the drop hammer to an initial position after an impact test; The measurement and control system comprises a main controller and a sensor, and is used for collecting the drop weight position and speed data in real time and dynamically adjusting the coil trigger time sequence and the discharge energy based on feedback control; the safety protection system is used for guaranteeing the safety of the test process; the electromagnetic acceleration system realizes the acceleration of the drop hammer according to a preset acceleration curve through the independent control of the multistage coils.
2. The drop hammer impact testing machine based on electromagnetic driving and resetting of claim 1, wherein the multi-stage electromagnetic coils of the electromagnetic accelerating system are of an air-core water-cooled structure, the coils are uniformly arranged along a drop hammer track, the inner diameter of each stage of coils is slightly larger than the drop hammer diameter, and adjacent coils are fixed through insulating partition plates.
3. The drop hammer impact testing machine based on electromagnetic driving and resetting of claim 2, wherein the top and the bottom of the multi-stage electromagnetic coil are respectively provided with an upper fixed end plate and a lower fixed end plate, a plurality of insulating pull rods penetrate through mounting holes on the upper fixed end plate and the lower fixed end plate, two ends of each insulating pull rod are pre-tightened through nuts, and the whole electromagnetic coil assembly is compressed into a rigid integral module for ensuring coaxiality of the electromagnetic coils.
4. The drop hammer impact testing machine based on electromagnetic driving and resetting of claim 3, wherein the electromagnetic lifting and resetting system further comprises a double-chain synchronous lifting mechanism, and the double-chain synchronous lifting mechanism is connected with the adsorption disc through a ball hinge and can adapt to deflection after drop hammer impact.
5. The drop hammer impact testing machine based on electromagnetic driving and resetting of claim 4, wherein the double-chain synchronous lifting mechanism comprises a driving motor, a synchronous shaft, a pair of chain wheels and two high-strength lifting chains, the driving motor is fixed at the top of the frame through a motor base, an output shaft of the driving motor is connected with the synchronous shaft through a coupler, two ends of the synchronous shaft are respectively provided with one chain wheel, one ends of the two lifting chains are respectively fixed on the two chain wheels, and the other ends of the two lifting chains are connected with lifting lugs on two sides of the adsorption disc.
6. The drop hammer impact testing machine based on electromagnetic driving and resetting of claim 1, wherein the frame and guiding system comprises a gantry type welding steel frame and a guiding assembly, and the guiding assembly comprises a linear guide rail and a linear bearing and is used for ensuring that drop hammer movement is free from unbalanced load.
7. The drop hammer impact tester based on electromagnetic driving and resetting as claimed in claim 1, wherein the safety protection system comprises a protective cover, an electric safety chain and software protection logic, and is used for realizing the closing and emergency stop control of an impact area.
8. The drop hammer impact tester based on electromagnetic driving and resetting according to claim 1, wherein the drop hammer is made of a main body made of magnetic conductive materials, a finished through hole is formed in the center of the main body, a counterweight cavity is arranged in the main body, the counterweight cavity is sealed through an end cover, the air gap distance is kept between the outer surface of the drop hammer and the inner wall of an electromagnetic coil, and a standard threaded interface is arranged at the bottom of the drop hammer and used for installing a replaceable impact head.
9. The control method of the drop hammer impact testing machine based on electromagnetic driving and resetting is characterized by comprising the following steps of: The preparation stage comprises the steps of positioning a drop hammer to a preset height through an electromagnetic lifting and resetting system, and setting target impact parameters; The acceleration stage comprises the steps of controlling the multistage electromagnetic coils to be sequentially electrified according to a preset time sequence and discharge energy based on feedback signals of the sensors, and applying electromagnetic thrust to the drop hammer to accelerate the drop hammer according to a preset acceleration curve; the impact stage, namely impacting the sample by the drop hammer at a set speed, and synchronously collecting force and time data; A reset stage, namely fixing the drop hammer through an electric control permanent magnet adsorption unit and lifting the drop hammer to an initial position; And a circulation stage, namely repeating the process until the preset test times are completed.
10. The control method of the drop hammer impact testing machine based on electromagnetic driving and resetting of claim 9 is characterized in that in the resetting stage, the electric control permanent magnet adsorption unit switches adsorption states through pulse current, and the double-chain synchronous lifting mechanism adopts a servo motor to drive a ball screw, so that drop hammer position control accuracy is ensured.

Description

Drop hammer impact testing machine based on electromagnetic driving and resetting and control method thereof Technical Field The invention relates to the technical field of drop hammer impact testing machines, in particular to a drop hammer impact testing machine based on electromagnetic driving and resetting and a control method thereof. Background The drop hammer impact test is an important method for evaluating the impact toughness, dynamic fracture performance and fatigue property of the material, and is widely applied to quality detection and scientific research in the fields of building materials, aerospace, automobiles and the like. The traditional drop hammer testing machine mainly adopts a pure free drop body mode, the impact energy of the drop hammer testing machine is completely determined by the drop hammer quality and the drop height, and the limitations that the impact speed is single and the low-elevation high-energy impact is difficult to realize exist, so that the test period and the test cost are increased. For example, in the impact resistance test of Ultra High Performance Concrete (UHPC), the first visible crack in the test specimen often requires tens of thousands of free fall impacts, which creates an urgent need for improved upgrades of test equipment and modes. In order to increase the impact speed, some of the prior art use spring boosting or pneumatic or hydraulic boosting to apply an initial acceleration to the drop hammer. However, these methods have the obvious disadvantage that the spring provides the initial acceleration for the drop hammer by storing elastic potential energy before release, but the spring is very subject to metal fatigue under repeated compression-release cyclic loads, resulting in attenuation of the elastic coefficient, breakage, low reliability, and frequent replacement and maintenance. The problems of complex system, high noise, high energy consumption, leakage risk and the like exist in the pneumatic and hydraulic pressure type hydraulic pressure pump. More importantly, the acceleration process of the two boosting modes is transient and can not be accurately controlled, the acceleration energy of the two boosting modes is fixed before the two boosting modes are released, the acceleration curve and the final speed of the drop hammer can not be dynamically regulated in the test, and the control accuracy is low. Therefore, the traditional drop hammer testing machine has the defects of low accelerating capacity, large part loss, uncontrollable impact speed range and low reliability. Disclosure of Invention The invention aims to provide a drop hammer impact testing machine based on electromagnetic driving and resetting and a control method thereof, which can solve the technical problems of low acceleration capacity, large part loss, uncontrollable impact speed range and low reliability of the traditional drop hammer testing machine. In order to achieve the above purpose, the present invention provides the following technical solutions: the invention designs a drop hammer impact testing machine based on electromagnetic driving and resetting, which comprises: The frame and the guide system are used for providing structural support and ensuring that the drop hammer moves along the vertical direction; the electromagnetic acceleration system comprises a plurality of stages of electromagnetic coils, wherein each stage of coils is independently connected with a capacitor group and a switch circuit and is used for applying electromagnetic thrust to the drop hammer; The electromagnetic lifting and resetting system comprises an electric control permanent magnet adsorption unit, realizes the adsorption and release of the drop hammer by switching the magnetic circuit state through pulse current, and is used for adsorbing and lifting the drop hammer to an initial position after an impact test; The measurement and control system comprises a main controller and a sensor, and is used for collecting the drop weight position and speed data in real time and dynamically adjusting the coil trigger time sequence and the discharge energy based on feedback control; the safety protection system is used for guaranteeing the safety of the test process; the electromagnetic acceleration system realizes the acceleration of the drop hammer according to a preset acceleration curve through the independent control of the multistage coils. As an optimal scheme, multistage electromagnetic coils of the electromagnetic acceleration system are of an air-core water-cooled structure, the coils are uniformly arranged along a drop hammer track, the inner diameter of each stage of coils is slightly larger than the drop hammer diameter, and adjacent coils are fixed through insulating partition plates. Further, the top and the bottom of the multistage electromagnetic coil are respectively provided with an upper fixed end plate and a lower fixed end plate, a plurality of insulating pull rods penetrate thr