Conical Spring Research Articles

Fatigue reliability analysis of mechanical components for airflow control in pneumatic solenoid valve

Pneumatic solenoid valves have been broadly used in vehicles to perform automatic control task. For safety reason, they have to be highly reliable and must have long fatigue lives. The failure of the mechanical components including a conical spring and rubber seal can induce airflow disorder, which renders the unreliability of the pneumatic solenoid valve. A method is presented to study the fatigue reliability of the mechanical components used for airflow control in a pneumatic solenoid valve. The statistics of the parameters used to derive the probability distributions of the stresses/strains in the mechanical components are obtained from the measurements of the parameter properties and static load testing of the components. The existing material S-N curves and stress/strain probability distributions are used to determine the reliabilities of the mechanical components. Based on the series system criterion, the fatigue reliability of the pneumatic solenoid valve with the consideration of the airflow disorder failure mode is computed for the life of 1 million cycles.

Manufacture of conical springs with elastic medium technology improvement

This article considers the manufacturing technology improvement by using an elastic medium in the stamping tool forming space to improve the conical springs performance characteristics and reduce the costs of their production. Estimation technique of disk spring operational properties is developed by mathematical modeling of the compression process during the operation of a spring. A technique for optimizing the design parameters of a conical spring is developed, which ensures a minimum voltage value when operated in the edge of the spring opening.

Computational study on the effect of a conical spring on handling of buses at low speed

Computational study on the effect of a conical spring on handling of buses at low speed

The Evaluation of Loosening of Small Bolts Under Transverse Vibration

Self-loosening of threaded fasteners sometimes occurs under dynamic loads such as vibration and shock. For mechanical structures, the self-loosening with rotation of threaded fasteners under transversely repeated load is particularly important. Although bolts of M8 and above have been studied by experimental methods and numerical analyses, there are few studies about small bolts of less than or equal to M5. In this paper, we have examined the loosening behavior of bolts of M3 and M5 by comparing with M10 bolts. As a result, we showed that small bolts easily cause slips on bolt bearing surfaces by very small amplitudes because of small initial bolt tension and small grip length, and when slips on bolt bearing surfaces occur, small bolts loose by the same behavior of M10 bolts. In addition, the loosening of threaded fasteners of M5 using plain washers, spring washers, conical spring washers or toothed washers are also the same as that of M10 bolts.

Computational study on the effect of a conical spring on handling of buses at low speed

Handling and ride characteristic are dependent to a large extent on the characteristic of a vehicle’s suspension system. This work explores the effect of the use of conical spring in place of conventional cylindrical profiled helical spring design in the handling of a bus at low speeds through full vehicle multi-body simulations. The bus was modelled using standard template available in ADAMSTM software package. The vehicle inertial properties were verified against properties in literature. The conventional spring characteristic (L) from ADAMSTM database was taken as reference and compared it with a non-linear characteristic (NL) based on literature data. The planned maneuover was to execute a right turn based on standard road dimension inputs from IRC 86:1983 at a constant speed of 30 km/hour with acceleration controlled by software module. Chassis displacements, displacements of spring were tracked to understand handling and ride quality. The variation of chassis displacements showed a significant improvement in ride characteristic of vehicle with most vibrations being damped in NL at time lower than the L characteristic suspension. All through the study, lateral acceleration was well within the rollover threshold and tire interaction forces did not exhibit any significant changes.

Механизм перемещения материала и её характеристики

The article provides the kinematics chart of mechanism of material movement of sewing machine and determination of law of lath motion at the different parameters of the system and its equalization. It also determins concrete values of linear speed of point Е of lever – laths at moving of material in sewing machines. A mechanism is worked out with the storage of energy as a conical spring, that operates at the horizontal moving of lath and a mechanism is executed as the reserved kinematics chain.

Tuned Nonlinear Energy Sink With Conical Spring: Design Theory and Sensitivity Analysis

This paper is devoted to the study of a nonlinear energy sink (NES) intended to attenuate vibration induced in a harmonically forced linear oscillator (LO) and working under the principle of targeted energy transfer (TET). The purpose motivated by practical considerations is to establish a design criterion that first ensures that the NES absorber is activated and second provides the optimally tuned nonlinear stiffness for efficient TET under a given primary system specification. Then a novel NES design yielding cubic stiffness without a linear part is exploited. To this end, two conical springs are specially sized to provide the nonlinearity. To eliminate the linear stiffness, the concept of a negative stiffness mechanism is implemented by two cylindrical compression springs. A small-sized NES system is then developed. To validate the concept, a sensitivity analysis is performed with respect to the adjustment differences of the springs and an experiment on the whole system embedded on an electrodynamic shaker is studied. The results show that this type of NES can not only output the expected nonlinear characteristics, but can also be tuned to work robustly over a range of excitation, thus making it practical for the application of passive vibration control.

軸直角方向振動下におけるボルト・ナット締結体の微小ゆるみ評価

For mechanical structures, it is important to prevent the self-loosening of threaded fasteners, but there are unclear points about locking performance under small transverse vibration. In this paper, we experimentally examine the performance of some locking fasteners, and we found that almost all the parts preventing loosening are reduced bolt tension little by little under small transverse vibration, while bolted joints using spring washers or conical spring washers are no effect of preventing loosening under small transverse vibration.

A compact targeted drug delivery mechanism for a next generation wireless capsule endoscope.

This paper reports a novel medication release and delivery mechanism as part of a next generation wireless capsule endoscope (WCE) for targeted drug delivery. This subsystem occupies a volume of only 17.9mm3 for the purpose of delivering a 1 ml payload to a target site of interest in the small intestinal tract. An in-depth analysis of the method employed to release and deliver the medication is described and a series of experiments is presented which validates the drug delivery system. The results show that a variable pitch conical compression spring manufactured from stainless steel can deliver 0.59 N when it is fully compressed and that this would be sufficient force to deliver the onboard medication.

Experimental Study on Thermal Performance of a Novel Solar Air Collector Having Conical Springs on Absorber Plate

This study presents a thermal analysis for a novel type of solar air heater. The thermal performance of a solar air collector having conical springs on the absorber plate is determined experimentally. A flat absorber plate (Type I) and the absorber plate with mounted conical springs (Type II) are designed and constructed, and their thermal performance is tested in the collectors. Experiments are performed for air mass flow rates of 0.06 and 0.07 kg/s. Thermal efficiency and collector outlet temperature are the main indicator for determining thermal performance. The efficiencies and energy distribution ratios are determined and compared for the collectors. The results of the experiments show that a substantial enhancement in the thermal efficiency is obtained with conical springs. Also, to this thermal efficiency increases with the rise of mass flow rate.

Development of a nonlinear conical spring bracing system for framed structures subjected to dynamic load

In this study, a nonlinear conical spring bracing (NCSB) system that can be applied as a lateral resistance component in framed structures was developed to mitigate the vibration effects of earthquake and wind. The NCSB device consists of two solid telescopic conical springs attached to steel wire ropes. The application of NCSB in framed structures, particularly moment-resisting steel frame (MRSF), improves the seismic behavior of the frame because of the variable action of the NCSB device. NCSB stiffness is not considerable in the low to medium vibration range compared with structural stiffness. Therefore, the inherent ductility of MRSF is unaffected because of the addition of the NCSB device to the frame. However, with its large displacement value, NCSB stiffness increases and prevents excessive displacement in structures. A mathematical model of the NCSB device that considers the effect of cable stiffness is developed and implemented in program code. Furthermore, the seismic behavior of eight types of NCSB applications in frames subjected to different earthquake accelerations is evaluated in terms of displacement, velocity, and acceleration, as well as compared with bare and brace frames. Results reveal the reduction influences of the NCSB device on framed structures. The best geometric configuration for the NCSB system is also determined by using the proposed numerical analysis.

軸直角振動下における各種ボルト・ナット締結体の微小ゆるみ挙動評価

Self-loosening of threaded fasteners sometimes occurs under dynamic loads such as vibration and shock. For mechanical structures, the self-loosening with returning rotation of screw thread under transversely repeated load is particularly important. Although many parts preventing the loosening of bolt-nut joint are being evaluated the locking performance of self-loosening, there are unclear points about small loosening of bolt-nut fastener under small transverse vibration. In this paper, using bolted joint with some parts for preventing the loosening such as the plain washer, the spring washer, the conical spring washer, the toothed washer, the flange nut, the double nuts, and so on, we have examined self-loosening behavior under transverse cyclic loading. As the result, it was confirmed that the joint with double nuts is excellent for preventing the loosening. And we found that almost all the parts preventing the loosening are reduced bolt tension little by little under small transverse vibration, while the bolted joint using the spring washer and the conical spring washer is no effect of preventing the loosening under small transverse vibration.

Soft tissue modelling with conical springs.

This paper presents a new method for real-time modelling soft tissue deformation. It improves the traditional mass-spring model with conical springs to deal with nonlinear mechanical behaviours of soft tissues. A conical spring model is developed to predict soft tissue deformation with reference to deformation patterns. The model parameters are formulated according to tissue deformation patterns and the nonlinear behaviours of soft tissues are modelled with the stiffness variation of conical spring. Experimental results show that the proposed method can describe different tissue deformation patterns using one single equation and also exhibit the typical mechanical behaviours of soft tissues.

Exact shell solutions for conical springs

ABSTRACTIn this article, the equations of equilibrium of conical disk springs of thin and moderate thickness are obtained through the variational principles for thin-walled and thick-walled conical shells. The closed form analytical solutions based on the common deformation hypotheses for the equations of thin- and thick-walled truncated conical shells were achieved. The results of calculations of reaction forces, based on analytical formulae, were compared with the results of finite element analysis, demonstrating the good accuracy of the derived formulae. The theory is extended to incorporate the anisotropy of the material. The problem for optimal anisotropy is solved. The minimal stiffness of the spring is achieved, if the upmost modulus of the orthotropic material is in the meridional direction. Analogously, the highest stiffness is attained, if the maximal elastic modulus circumferentially oriented. Engineering applications of the current theory potentially include Bellville springs and slotted disk springs with moderate flatness for automotive and industrial applications.

HEAT TRANSFER ENHANCEMENT AND FRICTION FACTOR ANALYSIS IN TUBE USING CONICAL SPRING INSERT

Role of the conical spring array for the heat transfer enhancement and pressure drop change in a pipe with constant heat flux boundary condition was investigated. Three different arrangements of conical spring array inserts were used in the experimental setup. Conical spring inserts with diverging conical spring, converging-diverging conical spring and converging conical spring array inserts arrangements were used. Water was used as a working fluid in the experimental setup. It was found that use of conical spring array inserts arrangement leads to enhancement in heat transfer. Higher heat transfer rate was achieved in the divergent spring array arrangement than the converging-diverging and converging arrangement. However, maximum friction factor is achieved in the diverging spring array insert arrangement. By increasing the Reynolds Number for different turbulator arrangement, the significant increase in Nusselt number was obtained. The enhancement in Nusselt Number for the diverging, converging-diverging, converging conical spring array arrangement was 645% ,431% and 259% respectively. The heat transfer enhancement efficiency can be evaluated based on the power consumption per unit mass of fluid. Heat transfer enhancement efficiencies were found for the divergent spring array arrangement up to 277% and for the convergent-divergent spring arrangement up to 212% and for the convergent spring array arrangement up to 153%.

Free Vibration Analysis of Two Types of Conical Springs

In this paper, a free vibration analysis of two types of conical springs is presented by using ANSYS software. The APDL programming is employed for the finite element modeling. Two types of conical springs, such as constant pitch and constant pitch angle, which are not distinguished in previous researches, are investigated. The results suggest that the two types of conical springs should be distinguishable in the dynamic applications.

Terminal 3 roof design and construction at Shenzhen Bao'an international airport, China

A combination of Italian design flair, German engineering and Chinese fabrication skill has delivered one of the world's most dramatic-looking airport terminals in just 6 years. The £600 million Shenzhen Bao'an airport Terminal 3 near Hong Kong went from a design competition in 2008 to a 45-million-passengers-a-year terminal in 2013. Looking like a cross between a manta ray and a plane, the entire 450 000 m2 building is skinned in a curving honeycombed space-frame roof. This paper focuses on the design and construction of the 1·2 km long roof structure, which includes conical disc springs to control thermal and seismic movements. Extensive use was made of digital engineering tools to define, analyse and fabricate the frame and cladding. This, together with development of practical and economic construction methods, helped achieve the bold architectural vision in a relatively short time.

Optimization and Prediction of Material Removing Rate in Die Sinking Electro Discharge Machining of EN45 Steel Tool

The main aim of this paper is to maximization of MRR in die sinking electro-discharge machining of EN45 material using Taguchi method. EN45 is a manganese spring steel with high carbon content. EN45 is used widely in the motor vehicle industry for leaf springs, truncated conical springs, helical springs and spring plates and many general engineering applications. MRR (Material Removal Rate) is the measure of material removal and is determined by evaluating the difference of initial weight of work piece to final weight of work piece and dividing by machining time. MRR is major factor in machining process and generally it decides the machining time. Considering the current short product life cycle, maximum MRR is always desirable. Therefore parameters affecting the MRR should be recognized and optimized for desire results. The experiments conducted based on the L27 Orthogonal array and results were optimized. Experiment were carried out using four input parameters viz. peak current (Ip), pulse on time (Ton), pulse off time (Toff) and voltage (V) with three different levels. The effects of different input parameters and effect of their combination on MRR determined using Taguchi and ANOVA table. It was observed that peak current and pulse off time are more significant factor for MRR.

Comparison of Cylindrical and Conical Helical Springs for their Buckling Load and Deflection

Buckling behavior of cylindrical helical springs subjected to axial load has already been illustrated in the past theories. Unlike cylindrical spring, the behavior of conical compression spring has both linear and nonlinear phase. Very little literature on buckling of conical springs can be found in the past. In this paper, an analytical buckling equation with its experimental verification has been proposed by authors and used it along with the existing theories to locate the phase of compression of conical spring at which buckling occurs. Subsequently, a comparison between cylindrical and conical springs has been made at the point of buckling of cylindrical spring in respect of their load and deflection. This would help to decide the suitability of conical springs against buckling failure of cylindrical springs under the given operating conditions.

Study Large Deformation Coil Spring Development For Robotics Submersible

In this work the present a theoretical study for the free vibration of cylindrical, conical and helical springs. Circular cross sections, and non-circular cross section, namely elliptical, are considered as well for the investigating of the frequency characteristics of the springs. The equations of motion are derived mathematically for springs with different geometries. The mode shapes are numerically implemented by using COMSOL 4.2 software package for three dimensional solid elements. The mode shapes configurations are determined by applying different force loads and boundary conditions for different number of spring turns. The results show that increasing the number of turns leads to decrease the spring stiffness and vice versa. Also decreasing turn number is a good strategy to distinguish between different mode shapes. Springs stiffness is directly proportional to coil diameter. It is also shown that the configuration of cylindrical-elliptical spring is prone to the applied force where the stiffness is lower among all other spring types with the same number of turns.