Low Carbon of Stamping Equipment

In the stamping process, the forming equipment produces plastic deformation of the metal sheet through the action of its actuator. The energy consumption of the stamping process is represented by the power consumption of the stamping and forming equipment, and the carbon emission of the stamping process is mainly due to the energy consumption in the stamping equipment. Therefore, it is necessary to carry out low-carbon optimization of stamping equipment in order to reduce the energy consumption of the stamping process. At present, the structural optimization of the forming equipment actuator belongs to the category of lightweight design, which can reduce the energy consumption during the movement of the equipment actuator, and optimizing the energy efficiency of the stamping equipment control system can reduce the energy consumption of the equipment control system. The lightweight design of the hydraulic press slider from the perspective of the structure optimization of the stamping equipment can effectively reduce the energy consumed by the slider action process to overcome the gravitational potential energy in the stamping process. At present, the main method is to combine the finite element technology with the topology optimization method to have lightweight design for key structural parts of stamping equipment. Li and others proposed an adaptive bionic design method combining topology optimization, size optimization and shape optimization, and applied it to the optimization process of key structural parts of stamping equipment. It reduces the use of raw materials in the manufacturing process of the slider under the premise of meeting the requirements of use. Zhang and others optimized the structure of a large hydraulic press to reduce its manufacturing costs, energy consumption and performance degradation. Some scholars have optimized the design of the key structure of the actuator to reduce the energy consumption during its use. For example, optimizing the slider guide system can reduce the frictional energy consumption during the slider action. In terms of improving the energy efficiency of the equipment control system, in order to quantify the energy dissipation of the hydraulic press, Zhao and others divided the hydraulic system into specific energy units for research according to the energy conversion characteristics of each component of the hydraulic press, and analyzed and quantified the energy dissipation characteristics of each unit. It is shown that the reason for the low energy efficiency of the hydraulic system is the mismatch between the load characteristics and the driving method.
 
In order to solve the above problems, the energy efficiency of the hydraulic system can be improved by the method of energy matching. At present, the matching methods of adjusting the output power and the demand power are mainly divided into two categories. One is through the system control method, such as the use of a permanent magnet synchronous servo motor pump control system to directly control the actuator without valve control devices or the use of speed control induction motors and quantitative pumps in the hydraulic system combined with load sensing control strategy. Controlling the drive redundancy of the equipment using the minimum energy method is adopted. Hongbo Zheng and others established the mathematical model of the servo direct-drive pump-controlled hydraulic system, analyzed the response speed, accuracy and stability of the system theoretically, and proposed measures to improve the dynamic performance and energy saving of the servo-direct-drive pump-controlled hydraulic system. Tianhao Peng and others studied the principle and existing problems of partial power matching between engine-pump and pump-load, and proposed the principle and method of power matching and coordination of hydraulic systems. Zheng and others studied the influence of loads, pipeline diameters and pump damping on the dynamic characteristics of a direct-drive pump-controlled hydraulic press system. Long Quan and others proposed a direct closed-loop control differential cylinder servo system of an adjustable speed pump, which can obtain dynamic characteristics equivalent to the valve control loop. Yonggang Peng and others designed a closed-loop hydraulic control system in which the servo motor directly drives the quantitative pump, and proposed a pressure and speed control strategy based on fuzzy control, which realized the precise control of the pressure and flow of the hydraulic system in the machining process. Another way is to use the method of sharing digital pumps. Arrange multiple quantitative pumps of different sizes in parallel and works continuously, a digital pump is formed. The pump unit determines whether to contribute a part of its flow through the valve group control matrix. The converged flow is then used directly to drive one or more hydraulic cylinders. Mikko and others applied the digital valve control system to the control of multi-chamber cylinders, which improved the controllability of the system and reduced energy consumption. Cristiano and others applied the on-off valve to the control process of the actuator of the digital hydraulic system, decomposed the large-flow quantitative pump or variable pump into multiple small-flow quantitative pumps, and analyzed the speed of the actuator, the inlet and outlet pressure and flow rate of the quantitative pump and the whole system; the results showed that the proposed hydraulic control system has smooth speed change, good dynamic characteristics, low power consumption and high energy storage capacity. Some scholars also improved energy efficiency by reducing the energy consumption of the hydraulic system. The energy recovery method is an important method to reduce the energy consumption of the hydraulic system. Convert a part of the potential energy into energy that is easy to store, and release it when needed. Energy regeneration methods were adopted, such as using a hydraulic accumulator to store kinetic energy or using a flywheel to store inertial energy. Triet and others developed an energy regeneration system (ERS). The kinetic energy is converted through the hydraulic accumulator without changing the flow, reducing the change of the displacement of the auxiliary unit, and increasing the use of several types of hydraulic pumps or motors. The experimental results show that the energy recovery efficiency of the test rig round trip of the designed system was improved from 22% to 59%. Potential energy generated by the vertically moving load can also be applied to the drive system again through recovery. Minav and others studied a hydraulic lifting system using a servo drive motor and its system energy recovery strategy. The hydraulic lift system is directly controlled by the servo drive motor. A potential energy recovery of up to 66% can be obtained at low power. Tao and others proposed to improve the energy recovery efficiency by optimizing the design of the permanent magnet synchronous generator in the hydraulic lifting potential energy recovery system.
 
To sum up, low-carbon manufacturing has become an inevitable demand for the development of the manufacturing industry, and has attracted extensive attention from the academic community. How to realize the quantitative characterization of carbon emissions in the manufacturing process and how to reduce carbon emissions in the manufacturing process is the focus of current research. However, there are few studies on low-carbon manufacturing in the stamping industry. There is still a lack of energy consumption analysis and carbon emission quantification methods for the stamping process. In terms of stamping process optimization, only a single optimization objective to improve forming quality is considered, and multi-objective low-carbon optimization methods for comprehensive forming quality and carbon emissions are still lacking. There is a lack of research on low-carbon optimization of forming equipment in the stamping process. Therefore, by analyzing the characteristics of energy flow and carbon emission in the stamping process, a low-carbon energy-saving optimization method for stamping and forming was proposed, and the carbon emissions were reduced in the stamping process from the perspective of low-carbon optimization of the stamping process and equipment.