Electromagnetic Valve Research Articles

Dynamics analysis and verification for slotted limited-angle torque motor in electromagnetic valve applications

Abstract Limited-angle torque motor (LATM) as a key component of the exhaust gas recirculation (EGR) valve, which can precisely control the position of the EGR valve, thus achieving dynamic adjust the amount of exhaust gas recirculation. This paper introduces the dynamic analysis, modelling and experimental validation of a concentrated winding axial-flux slotted LTAM with 4-poles/4-slots. Aiming at the prominent issues such as cogging torque and nonlinear torque characteristics in the operating region of slotted LATMs, analytical equations are derived based on the magnetic circuit to predict the torque-angle characteristics of LATM, covering both constant torque and linear torque regions. These equations help establish the relationship between performance and key parameters, enabling rapid design of LATM. The test results indicate that the proposed model can accurately describe the electromagnetic torque and cogging torque of the LTAM, with an error range of 5%. Utilizing the effective angle range proposed in this paper, an approximate linear relationship between the electromagnetic torque and current can be achieved, with a linear error of 6%.

Mechanical Characteristics and Miniaturization Design of the Electromagnetic Valve Used in Drilling Robots

The maximum radial size of the conventional three-bit four-way electromagnetic cartridge valve is greater than the largest containable size of the fluid control valve used for downhole robots. This paper proposes two kinds of solutions to reduce the radial dimension of the three-bit four-way electromagnetic insertion valve: one is to reduce the radial arrangement of the coil and increase the axial arrangement of the coil, and the other is to reduce the diameter of the moving iron core to reduce the winding radius of the coil. Using the theoretical model established in the following text, a simulation experiment was conducted. The results show that the movement of the valve spool is basically completed within 30 ms. Then, a matching experiment on the electromagnetic insertion valve was designed and conducted. The experimental results show that the opening time of the solenoid valve on the left coil is about 52 ms, and the opening time of the solenoid valve on the right coil is about 44 ms. The reaction time of the valve spool is suitable for the practical application of the solenoid valve. The significance of this paper is the reduced radial size of the three-bit four-way electromagnetic insertion valve. These improvements have reduced the size of downhole drilling robots, which facilitates the application of downhole drilling robots in narrower environments.

Header Height Detection and Terrain-Adaptive Control Strategy Using Area Array LiDAR

During the operation of combine harvesters, the cutting platform height is typically controlled using manual valve hydraulic systems, which can result in issues such as delays in adjustment and high labor intensity, affecting both the quality and efficiency of the operation. There is an urgent need to enhance the automation level. Conventional methods frequently employ single-point measurements and lack extensive area coverage, which means their results do not fully represent the terrain’s variations in the area and are prone to local anomalies. Given the inherently undulating terrain of farmland during harvesting, a control strategy that does not adjust for minor undulations but only for significant ones proves to be more rational. To this end, a sine wave superposition model was established to simulate three-dimensional ground elevation changes, and an area array LiDAR was used to collect 8 × 8 data for the header height. The effects of mounds and stubble on the measurement results were analyzed, and a dynamic process simulation model for the solenoid valve core was developed to analyze the on/off delay characteristics of a three-position four-way electromagnetic directional valve. Moreover, a physical model of the hydraulic system was constructed based on the Simscape module in Simulink, and the Bang Bang switch predictive control system based on position threshold was introduced to achieve early switching of the electromagnetic directional valve circuit. In addition, an automatic control system for cutting platform height was designed based on an STM32 microcontroller. The control system was tested on the hydraulic automatic control test rig developed by Shanxi Agricultural University. The simulation and experimental results demonstrated that the control system and strategy were robust to output disturbances, effectively enhancing the intelligence and environmental adaptability of agricultural machinery operations.

A single-coil-driven tristable electromagnetic mini valve with multiple working states

Electromagnetic mini valves have attracted great interest in medical devices for their excellent performance and high integration. In state-of-the-art research, most mini valves have only two working states, while certain ones featuring three to four working states necessitate multiple driving sources. To solve these problems, a novel tristable electromagnetic mini valve with three stable working states achieved by a single coil was proposed. The actuation mechanism of this mini valve mainly comprises a cylindrical magnet (CM) and a ring magnet (RM) coaxially arranged. In the absence of current through the coil, the stability of the magnets is upheld by their mutual repulsion and the attraction of the iron core. Upon modifying both the magnitude and orientation of the current, one of the magnets traverses from one terminus to another each time. The two magnets are either stationary at the start point or the endpoint. Thereby, four position relationships are formed, three of which are stable. The minimum response time and energy consumption are 3.75 ms and 0.013 J, respectively. The working pressure of the valve ranges from 0 to 200 kPa. The maximum flow rate and back pressure reach 10.5 L/min and 180 kPa, respectively. A tristable design contributes to lower energy consumption, and the three-working-state function actuated by a single coil facilitates a diminution in the size of the mini valve. Consequently, a diminished quantity of valves is realized for multiple degree-of-freedom pneumatic actuator control, which promotes the miniaturization of the whole system. The dimensions and performance of the proposed mini valve substantiate its potential in pneumatic medical devices.

Design of a continuously repeated impact method with constant amplitude based on Hopkinson bar: Principle and impact fatigue life testing

The lack of reliable testing methods and standards hinders systematic research on the impact fatigue performance of materials. The aim of developing an impact fatigue test method is to generate repeated impact loads with a constant amplitude, which is difficult to achieve using various existing impact test devices. This study investigated the principles of cyclic loading-resetting and constant-amplitude loading based on the split Hopkinson pressure bar (SHPB) system, established a novel impact fatigue test device, and verified the developed method by testing the impact fatigue life of a Ti-6Al-4V alloy. Electromagnetic valves, laser sensors, and a vacuum pump were used in the developed device to launch and reset the striker bar; a servo motor and laser sensors were used to reset the loading bars and specimen, and the entire system was controlled by a programmable controller to achieve continuously repeated loading. To achieve constant-amplitude loading, the conditions required to ensure that the specimen moves away from the incident bar before the returning stress wave reloads the specimen was derived. It was found that a constant-amplitude repeated impact on the specimen could only be achieved through the precise design of the geometric configuration and material of the loading bars. This method is considerably simpler than various existing methods based on energy absorption and is more applicable to impact fatigue tests. The verification tests showed that the highest loading frequency of the device was 0.5 Hz, the loading rate exceeded 105 kN/s, and the amplitude error of the repeated impact loads did not exceed 2.45 %. Under loads with the same amplitude, the impact fatigue life of a Ti-6Al-4V alloy was considerably shorter than the non-impact (low strain rate) fatigue life, which indicates the necessity of investigating the strain rate effect on the fatigue performance of materials.

Modeling a Solenoid Driver with Nonlinear Inductive Load Using Circuit Simulation and Magnetic Flux Measurement

This paper describes the procedure for creating a electronic simulation model of a solenoid power electronic driver with a nonlinear inductive load. Furthermore, it discusses the electromagnetic interaction between the driver and the load example electromagnetic valve. The consideration of nonlinear effects in the power electronic components MOSFET and diode is particularly important to distinguish their effects from the nonlinear behaviour of the inductive load.

The Synergistic Effect of the Filtration Area Controlled by the Electromagnetic Valve and Injection Pressure on Pulse-Jet Dust Cleaning Performance

In engineering pulse-jet dust collector applications, the filtration area and injection pressure are chosen mostly based on experience. The peak pressure is tested under different injection pressures and filtration areas controlled by an electromagnetic valve, and then comprehensively analyzes the effects of dust intensity, uniformity, and air consumption on dust cleaning to obtain a better filtration area controlled by an electromagnetic valve and injection pressure. The results show that considering the uniformity and intensity of dust cleaning, the filtration area of 33 m2 under the injection pressure of 0.4 MPa should be preferentially selected, with a standard deviation of 0.246 and a variance of 0.061. The filtration area of 27 m2 under the injection pressure of 0.3 MPa should be preferentially selected considering the unit air consumption, uniformity, and intensity of dust cleaning, the standard deviation of 0.252, and the variance of 0.064. The paper presents a theoretical foundation for selecting the optimal injection pressure and filter area regulated by an electromagnetic valve in pulse-jet dust collector systems.

Influence of AR injection on shielding layer properties and surface protection from transient high heat loads under the QSPA plasma exposures

The paper presents experimental studies of a shielding plasma layer formation in front of a tungsten surface exposed with hydrogen plasma in the QSPA-M test-bed facility under the conditions of additional seeding of argon (Ar) along the target surface into the zone of plasma-surface interaction. A pulsed gas injector on the base of a fast electromagnetic valve has been developed for the local injection of Ar. The injector is capable of generating a homogeneous argon gas flow with a maximum concentration above n Ar = 6 × 1023 m−3 and a pulse duration of 0.5 ms. It is shown that the increase in the argon gas density in front of the surface leads to an essential decrease (in 1.5–2 times) in the energy load delivered to the target surface. In the presence of a strong magnetic field (up to 1 T), both the thickness of the shielding layer and the fraction of energy dissipated by the shield increase further. Even for moderate energy densities of the QSPA plasma streams in the experiments with Ar gas injection, less than 40% of the impacting plasma load is absorbed by the tungsten surface. The results demonstrate that this additional shielding attributed to the formation of a dense Ar plasma layer in front of the exposed W surface would be favourable for the divertor armour performance, causing the decreasing erosion of plasma-facing components in the course of transient events in a fusion reactor.

Calculation Model and Accuracy Study of Transformer Standard Oil Preparation

This article introduces a treatment method, component concentration calculation model, and device for preparing standard oil using transformer oil. The base oil is prepared by deeply purifying the transformer oil and measuring its background value. Based on the target component concentration, the appropriate volume of standard gas is determined, and the background value of the combined oil is used in the component concentration calculation model to determine the theoretical value of the standard oil. The standard oil value that has been prepared is in good agreement with the anticipated target value, thereby simplifying the purification process and cutting down on the processing cost of used transformer oil. Simultaneously, a fully automatic integrated device has been developed for the advanced purification of transformer oil and the production of standard oil. This device comprises a vacuum pump, an oil storage tank, an electromagnetic valve, an oil cylinder, and various sensors, all managed by sophisticated software. The standard oil for transformers can be prepared and stored stably for an extended period. The standard oil output is processed under sealed and unchanging pressure conditions to ensure a consistent concentration of components in the standard oil.

Intelligent residual film recovery machine monitoring and control system

Domestic residue recovery machines in China still follow the traditional towed mechanical model, lacking automation and intelligent features. Under the key R&D project of Xinjiang Autonomous Region, our team has developed integrated intelligent agricultural machinery for cotton straw crushing and residue recovery. This research covers the monitoring and control system, including PLC control and communication, working parameter monitoring and adjustment, algorithmic control of electro-hydraulic actuators, and human-machine interface display. Compared to traditional models, this machine replaces the conventional chain-driven mechanical structure and diesel tractor traction power with a fully hydraulic integrated suspension drive and power system. Sensors, PLC, and a touch screen are utilized for real-time monitoring and display of parameters. Hardware components like electromagnetic switch valves, electro-hydraulic proportional valves, hydraulic cylinders, and software elements such as PLC programs and intelligent control algorithms are employed for electro-hydraulic switching and proportional control of certain working parameters and mechanisms. All parameter information is consolidated in the PLC host and expansion modules and displayed and controlled on the human-machine interface. The system was installed on the first-generation machine for indoor testing, revealing that the monitoring and control system used on the first-generation machine achieves parameter detection and adjustment of the actuating mechanisms. It incorporates more advanced functions compared to traditional residue recovery machines. However, there is still ample room for improvement in the overall intelligence of the machine. The control system’s structure requires adjustment, and certain functionalities of the overall mechanical structure and working components need optimization or upgrading. Detailed enhancements to the entire system will be made in the next-generation machine.

Cutting Fluid pH Value Maintenance in CNC Machine by Arduino Nano

Cutting fluid plays an important role in machining operations like milling, drilling, reaming, etc. In production industry such as automobile industries, aerospace industries, etc., soluble cutting fluids are mainly used for machining operations. The maximum service life of the cutting fluid is about 3 to 4 months in that industry, when they mixed with water, the cutting fluid will get dried out or converted into vapour due to heat generation and due to friction between the cutting tool and the components. The repeated use of cutting fluid for machining operations, the chemical and physical property of the cutting fluid will be changed. The proper mixing ratio of cutting fluid can be done with the help of Arduino nano device and valves, sensors. Automatic cutting fluid filling process can be done by proper Arduino coding. In the present study, the pH sensor is used to detect the pH level of cutting fluid and the Solenoid valves are electromagnetic valves, these valves are used to maintain the proper flow of cutting fluid and water mixture ratio, whenever the cutting fluid pH value differs from the fixed value, the pH sensor will indicate in Arduino nano. The mixing of cutting fluid and water is carried out by stirrer mechanism, which is attached at just above the cutting fluid tank. Control valve is used to control the flow of cutting fluid during the machining operation. The electric signal from touch sensor will stops automatically, when the cutting fluid in the tank reaches its maximum limit. In this paper, cutting fluid pH value is maintained automatically by Arduino nano device for CNC Machine in industries is discussed.

Design of a Drag-reducing System for Smart Bar Conveying Chain Plate

This paper presents a solution to the issue of high frictional resistance between the chain plate and guide rail in cigarette conveying systems, which can result in chain plate failure. The proposed solution is an intelligent drag reduction system that incorporates lubrication and automatic dust removal. The system includes a conveyor chain plate, supporting roller assembly, air knife dust removal assembly, chain plate lubrication assembly, and controller. The controller manages the dust removal assembly's air source output and the lubrication of the chain plate assembly through the opening and closing of an electromagnetic valve, which controls the oil output to decrease resistance. Experimental testing of the system shows that it effectively reduces the chain plate's frictional resistance in the cigarette conveying line, resulting in improved system efficiency.

Experimental and numerical investigation of the novel downhole intensifier controlled by electromagnetic valve

Stress release with rock slotting by ultra-high-pressure water jet is an effective method in reducing rock strength in the bottom hole caused by high in-situ stress in deep formation. The characteristics of duration and frequency of the water jet are vital for forming different grooves to release downhole stress. To improve the duration of the high-pressure water jet and modulate different jet frequency, a kind of downhole intensifier controlled by electromagnetic valve was developed and proposed. The water jet performance and the motion characteristics of the plunger of the intensifier were studied in various input pressure and switch frequency of the electromagnetic valve based on experiments, and a series of numerical simulations were conducted considering the input pressure, stroke, and area ratio of the plunger. The results indicate that the output waveform of the intensifier goes like a square shape. Increasing the input pressure and the area ratio of the plunger can enhance the output pressure while the duration of the peak pressure decreased. The stroke of the plunger shows a significant effect on the duration of the peak pressure and jet frequency. Adjusting the switching frequency of the electromagnetic valve can easily change the duration of peak pressure, which is beneficial for forming grooves with different characteristics. The research is believed to provide an important reference in drilling Engineering for deep and ultra-deep wells.

Design and Experimental Testing of an Overhead Rail Automatic Variable-Distance Targeted Spray System for Solar Greenhouses

Crop cultivation in solar greenhouses is affected by issues such as low levels of automation in spraying machinery, inefficient spraying, and a lack of suitable spraying equipment for vertically cultivated crops, all of which are in urgent need of resolution. To address these problems, this paper proposes a suspended-rail automatic variable-distance targeted spray system. The rated working speed of the spray system is 0.3 m/s, and the rated working pressure is 0.3 MPa. This system achieves precise spraying of crops at varying heights by dynamically adjusting the position of the spray nozzle. To ensure accuracy in spraying, the system employs a laser ranging sensor for real-time measurement of crop positions and spraying distances. Combined with a parameter processing scheme, the system generates control signals to adjust the operation of the electric push rod and electromagnetic valve, thereby dynamically adjusting the spraying distance and timing. Using vertically cultivated potted peppers as experimental subjects, this study compares the performance of fixed- and variable-distance spraying modes. The results indicate that, compared to the fixed-distance mode, the automatic variable-distance mode increases pesticide adherence by 16.65% and reduces pesticide usage by 29.58%. The proposed suspended-rail automatic variable-distance targeted spray system offers an effective technical solution for the precise spraying of vertically cultivated crops in solar greenhouses and thus contributes to improved pesticide utilization efficiency, reduced pesticide residue, and lower environmental pollution.

Multi-state, three-way, normally open mini valve based on 3D printed flexible magnets using origami-inspired magnetization

Electromagnetic mini valves for controlling pneumatic soft actuators are attracting widespread interest in recent years. However, it is known that the traditional electromagnetic valves on the millimeter scale generally have three or fewer working states, and their moving parts are usually permanent magnets with a special shape that needs expensive manufacturing. To overcome these problems, this study aims to develop a mini valve with four working states based on flexible magnets at a low fabrication cost. We take full advantage of low-cost 3D-printed magnets’ physical and magnetic properties and improve their performance through origami-inspired magnetization. A fixed-beam-structure flexible magnet is proposed to control this valve via deformation so that valve’s two sides can be driven independently, resulting in four working states. Compared with conventional sintered magnets, 3D printing magnets can be manufactured quickly and affordably. Due to the proposed valves’ more operating states than the state-of-art three-way ones, they are proven to reduce the number of small control elements in the pneumatic system. The maximum flow rate of the valve at 5 kPa air pressure was 0.81 l min−1 at the power consumption of 20 W. This mini valve has the potential in controlling multi-degree-of-freedom pneumatic soft actuators.

Validation of a Novel Electromagnetically Operated Free Flow Liquid Dispensing System

Repeat dispensing of liquids is a common requirement in many industries, often performed using automated machinery. These instruments often use complex mechanisms requiring expensive parts that may not be readily available. In resource-constrained regions there is a need for a simple device capable of reproducibly dispensing a controlled volume of fluid accurately. We evaluated the performance of a semi-automated liquid dispenser made from readily available parts that utilizes a programmable timer to trigger the activity of an electromagnetic valve, which allows delivery of liquid from a storage tank to the delivery nozzle via a flexible tube. The device was programmed to deliver a wide range of volumes and a gravimetric analysis of dispensed liquid was performed. The dispensed liquid maintained a linear relationship with the delivery time within the tested delivery range of 0.05 gram to 1.8 gram. It demonstrated high accuracy (>95%) and precision (coefficient of variation of <10%) for dispensing quantities more than 0.2 gram. However, the accuracy and precision suffered significantly below 0.2 gram. By changing nozzle diameters, we found a similar linear relationship between time and dispensed water weight for all tested nozzle sizes. By using a wide range of nozzle diameters, we could increase the range of delivery weight from 0.03 gram to 28.4 gram, with a very similar precision. This simple instrument is a user friendly, cost-effective, resource-efficient and reliable alternative for repeatedly dispensing a wide variety of liquids with various industrial applications, within a given volume range.

Research on Positioning Control Strategy for a Hydraulic Support Pushing System Based on Iterative Learning

At present, the positioning control of the hydraulic support pushing systems in fully mechanized mining faces uses an electrohydraulic directional valve as the control component, while the current research mainly focuses on servo valves, proportional valves, high−speed on−off valves, and electromagnetic directional valves. At present, the positioning control for electrohydraulic directional valves is only a simple logical control. Therefore, in order to improve the positioning control accuracy of the hydraulic support pushing system, a predictive positioning control strategy based on iterative learning was designed. Firstly, mathematical modeling of the hydraulic support pulling process was carried out, and its state−space equation was established. Secondly, an iterative learning controller with a state observer was designed, in which the iterative learning method was used to predict the control advance in the positioning process, and the state observer was used to estimate the parameters that could not be measured by the system, so as to improve the control accuracy in the broaching process. Then, a SimulationX–Simulink joint simulation model of the position control system of a multi−cylinder pulling hydraulic support was built, and the designed iterative learning controller was compared with the BP neural network controller. Finally, a test platform for the hydraulic support pushing system was built, and the proposed control strategy was experimentally verified. The research results show that the iterative learning control strategy proposed for the electrohydraulic directional valve not only simplifies the design process of the controller but also has higher positioning control accuracy. The single−cylinder positioning control accuracy can be controlled within 10 mm, and the multi−cylinder coordinated positioning control accuracy can be controlled within 15 mm, which meets the accuracy requirements of the site.

Improving the Efficiency of Spark-Ignition Internal Combustion Engine Using a Novel Electromagnetic Actuator and Adapting Increased Compression

This paper presents an empirical study of a spark-ignition internal combustion engine with modifications made to increase its effectiveness. The modification was implemented bi-directionally in terms of changes to the compression ratio and changes to the engine’s valve train. The compression ratio was increased by 2.3 units by design and a hybrid intake valve opening control was used in the engine’s valve train. The hybrid control involved autonomous control of one of the inlet valves with a dedicated electromagnetic actuator. The designed electromagnetic actuator was mounted downstream of the single-cylinder engine’s intake system’s modified camshaft to control the effective compression pressure build-up. Field calculations were carried out for the electromagnetic actuator’s design variants and its current characteristics were determined. The multivariate calculations were carried out in order to find the quasi-optimal geometry of the actuator. The width and height of magnetic field coils and the dimensions of the stator poles were changed, while maintaining the same external dimensions of the actuator to enable its mounting in the cylinder head system. In the next step, the prototype of the actuator was made and placed on the combustion engine in order to conduct the experimental investigations. The work was aimed at improving the internal combustion engine’s efficiency at the low load range, as this is load range in which it has low efficiency despite it being the most often used during normal vehicle operation. The original measurement stand was prepared, and many tests were carried out in order to investigate the influence of the electromagnetic valve on the combustion engine characteristic. This improved the internal combustion engine’s efficiency at its low-load range by up to 25%. Both calculation and measurement results are presented in form of graphs.

ГРУППОВАЯ СИСТЕМА СМАЗКИ ЭКСКАВАТОРА ЭШ ЛУБРИКАТОРОМ С ПНЕВМАТИЧЕСКИМ ПРИВОДОМ

A group lubrication system of mechanical components for a walking excavator is proposed, the original design of a lubricator with a pneumatic drive and a controlled electro-magnetic valve is developed

Basic study on high precision positioning in electromagnetic valve drive system for improving internal combustion engine using linear actuator

In recent years, further improvements in the performance of internal combustion engines to reduce environmental burden have been demanded. The combustion state of an engine is affected by the parameters of the dynamic valve system, such as the opening/closing timing and the lift of the intake and exhaust valves. Therefore, we investigate an electromagnetic valve-drive system in this study. Two models are created to improve the magnetic circuit and increase thrust. To investigate the thrust characteristics of these actuators, an electromagnetic field analysis is conducted using the finite element method. Meanwhile, to investigate the effect of the yoke material on the thrust, an electromagnetic field analysis is performed based on materials with different saturation magnetic flux densities and magnetic permeabilities.