High-speed Solenoid Research Articles

708 高速ON/OFF電磁弁を用いた水圧シリンダの位置制御(流体パワーによる駆動と制御II,オーガナイズドセッション,人体のコンピュータモデルの作成とその応用,特別講演)

708 高速ON/OFF電磁弁を用いた水圧シリンダの位置制御(流体パワーによる駆動と制御II,オーガナイズドセッション,人体のコンピュータモデルの作成とその応用,特別講演)

A Study on Noise and Flow Fluctuation Reduction of Water Hydraulic Two-Stage High Speed Solenoid Valve Using Leakage Flow around the Main Poppet as Pilot Flow

In order to improve the large flow fluctuation and the noise of water hydraulic two-stage high speed solenoid valve, the method for using proportional poppet as the main valve as well as setting the maximum opening area of the pilot valve as the main valve does not reach to the stroke end is proposed. The effect on the reduction of flow fluctuation and noise is examined with experiment by using two kinds of prototype proportional poppet. As an experimental result, it is verified that the relation between the main and pilot flow rate is linear and the design method of the proportional poppet for water hydraulic use is valid. Furthermore, through the application of proposed method, it is identified that considerable amount of the flow fluctuation is reduced and approximately 3 dB of sound pressure level is reduced in comparison with the water hydraulic two-stage high speed solenoid valve which uses ordinary poppet.

水圧用２段式高速電磁弁のＨＩＬＳによる主弁動特性解析

This study is concerned with the dynamic analysis of the main poppet of two-stage water hydraulic high speed solenoid valve using Hardware-in-the-Loop Simulation (HILS). Since the behavior of a main valve of a two-stage water hydraulic high speed solenoid valve is difficult to measure, HILS technology is applied as an efficient and a precise method for the analysis of dynamic characteristics of this valve. In order to apply HILS to this valve, a dynamic modeling of the main valve is derived. From the results of HILS analysis, it is confirmed that the dynamic characteristic of the main valve is satisfactory. Furthermore, the validity of HILS analysis of this study is verified by experiment.

水圧用直動形高速電磁弁の開発

When tap water is used as a pressure medium, the structure and material of an oil hydraulic high-speed solenoid valve can not be used because internal leakage and rust can occur. Accordingly, the authors have proposed a novel water hydraulic high-speed solenoid valve. This study is mainly concerned with the development of direct-driven water hydraulic high-speed solenoid valve. Through the investigation of soft magnetic material which has anti-corrosion and low eddy current characteristic, a solenoid design method using soft magnetic stainless steel instead of soft magnetic iron was established. Furthermore, a high-speed driving circuit, which compulsively imprints over-excitation voltage and demagnetization voltage onto the solenoid, is used in order to reduce the switching time of the water hydraulic high-speed solenoid valve. From the linear characteristics of Duty and mean flow, as well as fast switching time within 1.5ms, the validity of solenoid and direct driven valve design method for water hydraulics is verified.

Design and investigation of high-speed, large-force and longlifetime electromagnetic actuators by finite element modelling

Electromagnetic (EM) solenoid actuators are widely used in many applications such as the automobile, aerospace, printing and food industries where repetitive, often high-speed linear or rotating motions are required. In some of these applications they are used as highspeed `switching' valves for switching pneumatic channels. This paper describes the finite element (FE) modelling and design of high-speed solenoid actuators. Operating at frequencies between 150–300 Hz, these actuators are unique in terms of the large force they produce (8–15 N) and the requirement for very long lifetime (2-5 billion cycles). The complex nature of electromagnetic, motional and thermal problems is discussed. The methodologies for FE modelling of such high-performance actuators are developed and discussed. These are used for modelling, design, performance evaluation and prediction of the above high-speed actuators. Modelling results showing some of the key design features of the actuators are presented in terms of force produced as a function of various design parameters.

Water hydraulic high-speed solenoid valve Part 1: Development and static behaviour

This study is concerned with the development of a novel water hydraulic high-speed solenoid valve with a two-stage mechanism. By virtue of the two-stage mechanism and the proposed particular design, which use the leakage flow through the clearance between the main poppet and sleeve as the internal pilot flow, it is possible for the developed valve to have unique features, such as no internal leakage, a switching time of approximately 2 ms, maximum flowrate of 9 1/min and maximum pressure of 14 MPa. Based on the preliminary experimental results using a fabricated prototype valve, the performance of the developed valve has been improved. It can be seen from the experiment that the static flow characteristic according to the duty ratio of the improved valve is very satisfactory. As an application of the developed valve, the speed control of a water hydraulic motor has been conducted using the pulse width modulated (PWM) control of the developed valve. It was found that the developed valve is suitable for the PWM control method and can be implemented as the flow control valve of water hydraulic systems.

Water hydraulic high-speed solenoid valve Part 1: development and static behaviour

Water hydraulic high-speed solenoid valve Part 1: development and static behaviour

Development of a high-speed solenoid valve: an investigation of the importance of the armature mass on the dynamic response

Traditional design criteria for electromagnetic valves are discussed. Performance criteria for them are also shown. A method for investigating the armature mass importance on the EFI performance is proposed. This method is based on energy losses of a mass-spring-damper system (MKsB). It was found a range of values in which the dynamic response can be improved. Results are verified and discussed.

Optimal design of the magnetic field of a high-speed response solenoid valve

The high-speed response solenoid valve (HSV) plays a key role in determining an electro-hydraulic automatic system’s overall performance. As an approach to improving the HSV, this paper presents an optimal design method on the HSV’s magnetic field by making a full consideration of the effects of various soft magnetic material’s properties and geometries on the HSV’s electronic performance. The proposed optimal design method, based on the HSV’s modeling, simplification and subsequent simulation for obtaining accurate results on the distribution of the HSV’s magnetic field and flux-line as well as magnetic force, can achieve a larger magnetic force and a lower power of an HSV by adjusting the structural parameters of the solenoid valve and selecting various soft magnetic materials that are of different B– H (flux density vs. field intensity) curves. The researching results show that for the designing of for HSVs, the proposed optimal design method can enhance the reliability and accuracy, reduce the cost, and shorten the cycle, and hence has practical value for engineering purposes.

A DEVELOPMENT OF WATER HYDRAULIC HIGH SPEED SOLENOID VALVE

Oil Hydraulic systems are employed in a wide range of engineering fields because of their rapid response and high power density. However, increasing public awareness of environmental issues call for environmentally friendly pressure medium like water to prevent environmental damage caused by potentially harmful material leakage from oil hydraulic system.In this study, a water hydraulic high speed solenoid valve with two stage mechanism and no inner leakage is developed. The particular feature of this valve is the utilization of the leakage from the clearance between main poppet and sleeve as inner pilot flow. The experimental results using the prototype valve show excellent response characteristics and that proposed valve is valid for the control of water hydraulic systems. It is also discussed to improve the performance of this valve by the alteration of the design parameters.

Hydraulic anti-lock braking control using the hybrid sliding-mode pulse width modulation pressure control method

This study integrates the discrete on-off operation of hydraulic high-speed solenoid valves and the pulse width modulation (PWM) method to achieve a quasi-continuous braking pressure control. Sliding-mode control is applied here due to the non-linear nature of the solenoid valve. The hybrid compensating method presented here compensates for the mechanical and electrical delay of solenoid valves, obtaining more precise control results and keeping the robustness of the sliding controller. Following verification of the braking pressure controller on a test stand, an anti-lock braking controller of a passenger car is designed by use of tyre tangential deceleration feedback. This anti-lock braking controller is also verified on a dynamic test stand. Braking experiments on both dry and wet road surfaces are simulated.

A study on the design and application of optimized solenoid for diesel unit injector

With the Environmental Protection Agency (EPA) regulating the amount of NOx, Particulate, HC and CO at all driving conditions, emission standards for diesel engines are becoming more stringent than ever. To meet future emission regulations, researchers have proposed two solutions based on injection control, the common-rail type injection system, and the unit injection system. Most researchers agree that the electronically controlled unit injector, which realizes high injection pressure and precise control of SOI (Start Of Injection) and injection quantity, has an advantage in meeting future emission regulations. In order to control the start and end of injection, each unit injector contains a time-controlled high speed solenoid valve. Thus, the fuel injection quantity is determined by the time interval between closing and opening of the solenoid valve. This study introduces a method for the design of the solenoid which is installed in the unit injector. It is shown that there are certain significant parameters to be optimized to improve solenoid performance: inductance, stroke, input voltage, coil resistance, load and switching time.

Characteristics of a liquefied butane spray

The characteristics of a butane spray from pintle-type injector were studied by droplet velocity and diameter measurements and high speed photography. The accumulator type injector operated off a common rail fuel supply system operated at 13 MPa, and was controlled by a high-speed solenoid valve. Injection was carried out in a chamber at ambient temperature and at the pressure above (0.37 MPa) and below (0.15 MPa) the fuel vapor pressure. Two component phase/Doppler particle analyzer and traverser were used to obtain the droplet diameter and the velocity at numerous locations in the spray. The entire injection event was analyzed as a time-average and also subdivided into three temporal intervals. A, B, and C. The high-speed photographs showed a narrower cone angle during the quasi-steady spray period at the 0.37 MPa chamber pressure compared to the 0.15 MPa case.

Fuzzy PWM Control of the Positions of a Pneumatic Robot Cylinder Using High Speed Solenoid Valve.

In the study, instead of using expensive servo valves, three inexpensive high-speed solenoid valves were adopted and a fuzzy PWM controller was designed to control the linear and rotational positions of a pneumatic robot cylinder. The modified differential PWM method is proposed to eliminate the dead zone and to improve the nonlinear characteristics between the pressure difference of the cylinder and the duty ratio of the PWM control signal. The experimental results have shown that the servo pneumatic system with the proposed fuzzy PWM controller exhibits good performance.

Somatosensory cortical efferent neurons of the awake rabbit: latencies to activation via supra--and subthreshold receptive fields.

1. Latencies to peripheral sensory stimulation were examined in four classes of antidromically identified efferent neurons in the primary somatosensory cortex (S1) of awake rabbits. Both suprathreshold responses (action potentials) and subthreshold responses were examined. Subthreshold responses were examined by monitoring the thresholds of efferent neurons to juxtasomal current pulses (JSCPs) delivered through the recording microelectrode (usually 1-3 microA). Through the use of this method, excitatory postsynaptic potentials (EPSPs) and inhibitory postsynaptic potentials (IPSPs) were manifested as decreases and increases in threshold, respectively. Efferent populations examined included callosal (CC) neurons, ipsilateral corticocortical (C-IC) neurons, and descending corticofugal neurons of layer 5 (CF-5) and layer 6 (CF-6). Very brief air puffs (rise and fall times 0.6 ms) were delivered to the receptor periphery via a high-speed solenoid valve. 2. Whereas all CF-5 neurons had demonstrable suprathreshold excitatory and/or inhibitory responses to peripheral stimulation, most CC, C-IC, and CF-6 neurons did not. CC and CF-6 neurons that yielded no suprathreshold response to the stimulus had lower axonal conduction velocities than those that did respond (P < 0.0001 in both cases). However, subthreshold receptive fields could be demonstrated in many of the otherwise unresponsive CC (81%), C-IC (88%), and CF-6 (43%) neurons. The subthreshold responses usually consisted of an initial excitatory component (a decrease in the threshold to the JSCP) and a subsequent long-duration (> 80 ms) inhibitory component. A few neurons (1 CC, 1 C-IC, and 5 CF-6) showed an initial short latency inhibitory response in the absence of any excitatory component. 3. Some CC and C-IC neurons yielded supra- and/or subthreshold responses to peripheral stimulation at latencies of 6.1-7 ms. All such neurons were found at intermediate cortical depths (thought to correspond to deep layer 2-3 through layer 5). It is argued that such latencies are indicative of monosynaptic activation via thalamic afferents. Very superficial CC and C-IC neurons, and all CF-6 neurons responded to latencies of > 7 ms. All CF-5 neurons responded to latencies of > 8 ms, although many were found at the same depth as the deeper CC and C-IC neurons that responded at monosynaptic latencies. These results indicate that cortical cell type as well as laminar position are important factors that determine the sequence of intracortical neuronal activation after peripheral sensory stimulation.

Study on the Oxidation Process of Unburnt Hydrocarbons in the Exhaust System of a Spark Ignition Engine. 1st Report. Characteristic of Time-Resolved Measurement System of Hydrocarbon Species.

Oxidation in the exhaust systems of spark ignition engines is one of the important properties characterizing the behavior of unburnt hydrocarbons. A time-resolved measurement system of hydrocarbon species which consists of a high speed solenoid valve and a gas chromatograph is developed. It is confirmed experimentally that this system can be used to measure hydrocarbon species when the engine is rotating in both the cold starting and warmed-up periods. The difference in the oxidation processes in the exhaust system in methane-fueled and propylene-fueled engines is discussed in relation to the data measured using this system.

Development of a high-speed solenoid valve: investigation of solenoids

The authors have developed a high-speed solenoid valve with a 1 ms switching time to control diesel engines electronically. In this paper, the authors focused their attention on developing the solenoid itself, investigating methods to be used for the fast operation of the solenoid valve. First, by using a mathematical model, they quantitatively examined the effects of design particulars, such as the dimensions of the solenoids and the number of turns of coil, on the switching time. According to the results obtained by the above examinations, they studied an effective method for fast switching. Next, they investigated appropriate and comprehensive methods that would satisfy given specifications under the various restrictions inherent in the solenoid valve's operation. In the final stage, they manufactured solenoid valves in accordance with the investigated methods, and evaluated their performance. >

Development of a High-Speed Solenoid Valve. Experimental Results under Actual Loads.

Development of a High-Speed Solenoid Valve. Experimental Results under Actual Loads.

Development of a High-Speed Solenoid Valve. Investigation of the Solenoids.

Development of a solenoid which was used for the high-speed solenoidvalve with a 1 ms switching time is discussed in this paper.First, by using the mathematical model, we quantitatively studied the effects of design particu lars, such as the dimensions of the solenoids and the number of turns of coil, on the switching time. Next, we investigated the suitable and comprehensive conditions that would satisfy given specifications under the various limitations inherent in the solenoid valve's operation.Finally we manufactured the solenoid valves in accordance with the effective methods for performing fast switching, and evaluated their performance.

SIMPLIFIED CONSTRUCTION AND PERFORMANCE OF A DEVICE FOR PARTICLE BOMBARDMENT

Design modification of a particle inflow-type gun for particle bombardment significantly simplifies construction and reduces fabrication time. The gun consists of a high-speed electric solenoid valve mounted on and through a vacuum jar. DNA-coated tungsten particles are placed on the support grid of a filter housing and accellerated by a burst of pressurized helium, which is controlled by a timer. Specimens are held between plastic screens and their distance from the particle support grid is adjusted with a miniature laboratory apparatus positioner. Transient expression of GUS in cantaloupe cotyledons and grape somatic embryos was equivalent to that obtained with a conventional particle inflow gun. The device was constructed with locally-available hardware in 40 minutes using a hand drill, some thread taps and a thread die.