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Fine machining processes are of great importance in automotive series production, e.g. the machining of valve guide and seat in the cylinder head of a combustion engine. In industrial manufacturing processes, disturbances are inevitable and provide a measure of uncertainty in each production step. Increasingly, the influence of such uncertainties is being evaluated using simulation models. In this paper, a modeling approach for simulation of multi-stage fine machining processes with step tools is presented and investigations regarding influence of uncertainty caused by disturbances are performed.

In production processes uncertainty has a great impact on the product quality as well as production costs. In automotive industry the reaming of valve guides in a cylinder head of a combustion engine is a quality determining process. Due to the force fitting of the valve guides into the cylinder head the final reaming process has to deal with increased uncertainty. On the other hand, the finished hole is closely tolerated. To ensure the process reliability the admissible tolerance must be strictly met even in case of uncertainty. This paper presents a possibility to achieve process reliability by a modified process chain with an additional pilot reaming tool. Thereby, the effect of different cutting edge preparation is also analyzed. Further, the influence of the pilot reamer geometry on the final hole quality is investigated.

When designing the servo valve with different structure parameters, the influence of the interaction between the liquid and the solid on the performance of servo valve can only be obtain by the method of experiment, and then it can increase the time and cost of designing the servo valve. The liquid-solid couple method can obtain the influence of structure parameters on the performance of servo valve under the circumstance of reducing the experimental cost and time. The paper chooses the servo valve of A and B as models for study, The text adopts FSI method to analyze the flow field of double nozzle baffle electro-hydraulic servo valve prestage through the software of ANSYS, research the change of the prestage flow field by deflection of loaded armature baffle components, contrast and analyze the change of velocity, pressure, power loss and flow coefficient of fixed choke, nozzle, return port, and the displacement of the valve core of slide valve, stress of armature baffle components, pressure at both ends of spool. Summarize the advantages and disadvantages of A and B servo valve, and find different parameters of servo valve have different performance, it is difficult to find a common structure and size. It can help us to select the requirement structure by using fluid-structure interaction, reduce experiments and save cost.

The main rejections in the machining sections are exhaust valve port leak, injector bore blow hole, induction passage punchered, inlet valve port leak, top face unwash, valve guide hole blow hole, top face leak, joint face unwash, induction face unwash, rear face unwash, valve port unwash, water mixing with oil., water passage blocked, emf leak, injector bore leak, inlet valve port blocked, water way leak, oil way leak and defective jig location pad. This paper describes the method by which the rejections while maching the cylinder head, is minimized.

Four types of exhaust valve models are established, the lightweight on engine exhaust valve is designed. The results on thermal mechanical coupled analysis of four exhaust valve models show that: The maximum values of mises stress appear in contact surface between the valve cone and valve seat; Comparing the maximum mises stress, as wall thickness of the hollow valve increases, there are gradual decrease trends in the same positions of the valve cone, the locking groove, neck and end face of the valve disc. The research on the stress distribution of exhaust valves and the variation law between hollow valves′s strength and their wall thickness provide a good reference for improvement in the future.

For the reality of the variable pressure in the oil field, an adjustable disk choke valve is introduced in this paper. The structure and working performance of the valve is described in detail, too. The field application of the valve shows that the valve has such advantages as simple structure, quickly facilitate, easy installation and cleaning, long service life, safe and reliable, all these leads to the broad application prospect of the valve.

The paper deals with the load of the head of the engine. Head of SI engine, which has molded seat of intake and exhaust valve, is one of the most complex parts of the engine. It contains intake and exhaust ports, spark plugs, timing of the mechanism and channels for cooling and lubrication. Much of the final form of this component also contributes its load, which is both heat and mechanical. The biggest influence on the deformation of embedded saddles exhaust valve has a temperature distribution in the cylinder head. These temperatures are influenced by many factors, especially temperature and coolant flow, load and engine speed, which affect the combustion process and exhaust gas temperature (the engine mode is constantly changing, therefore the thermal load on the valve seats is different). In our paper we will only deal with the heat load of the cylinder head of the engine. Currently, the most common use of appropriate software tools for determining the distribution as voltage or temperature. The simulation results may not always be identical to the actual situation, so it is necessary to perform by verification. The paper described measurements of temperature on the inserted valve seats cylinder head of the engine.

Rotary valve is a device to achieve fast commutation hydraulic transmission . Rotary valve is driven by a hydraulic motor drive and can achieve rapid conversion of the hydraulic circuit . Rotary valve spool by a rotating shaft , housing , shafts and bearings and other components. Guide grooves machined on the spool shaft is evenly distributed for hydraulic cylinder into the oil and return oil conversion. The coordinate gap between the spool shaft and valve chamber bore Because will affect the leakage in the leak. How to improve the guide groove structure? We can put the guide groove by high and low partition instead of overlapping arrangement. Reducing leakage within the valve chamber and Meet with the requirements of the spool shaft and valve chamber bore.

The face of the valve seat sealing surface design, the finite element analysis and calculation of ball valve seat sealing surface and angle of the design method is studied. Through 3D CAD technology for ball valve design, guide 3D design model to finite element analysis software to calculate ,reveal the sealing load distribution of pressure in the valve seat sealing surface, sealing pressure values are obtained, through the valve seat sealing surface design Angle analysis, to obtain the optimal value of sealing surface angle.

the low pressure oil chamber and the high pressure oil chamber act directly on Both sides of the rotary valve. It will be large axial force to the valve body If the system working pressure is greater. The resulting outcome is low vibration frequency of the rotary valve driven hydraulic exciter. How to improve the hydraulic exciter frequency?We can improve the speed of the rotary valve or increase the number of rotary valve guide groove. But if we increase the tank guided number ,the diameter of the rotary valve spoo must be increased. Design a rotary valve without axial force can solve the problem of the rotary valve spool shaft size restricted. By calculation and analysis of the rotary valve spool suffered axial force . The work of a single rotary valve chamber pressure problems can be solved spool axial force

The hydraulic slide valve with round orifice spool is often used in hydraulic control system. But it is prone to rotate when the hydraulic oil flow is large. The three-dimensional fluid analysis technology was used to numerically simulate the flow field in the hydraulic slide valve. By using the pressure and velocity characteristics generated for different spool structures by the CFD numerical analysis, the main reason of slide valve rotation was analyzed, which can provide basis for the optimal design of the slide valve structure.

High contact stress between the vane tips and the cam ring is one of the main obstacles to improve the working pressure of a water hydraulic vane pump. A pressure-reducing valve for regulating the bottom pressure of the vanes at the pump suction zone is presented in this paper. Through optimization and simulation, it is found that the throttle structure has great influence on the dynamic performance of the pressure-reducing valve, and the triangular-rectangular groove is proved to be more suitable for the valve among all the investigated grooves. The theoretical analysis results show that the use of the pressure reducing valve can obviously reduce the contact forces between the cam ring and the vanes at the suction zone of the pump. The work in this research provides a feasible solution to improve the working pressure of a water hydraulic vane pump.

It has been analyzed the assembly of electromagnetic drive - inlet valve operating in camless valvetrain. The valve made of TiAl alloy has mated with its guide made of phosphor bronze. The scheme of electromagnetic valve drive has been shown in the article. The head aim of the motion control for such valve has been to provide small values of the valve velocity near the valve seat position. The aim of present analysis is to study the course of friction force between valve stem and its guide against time during use of control algorithm presented in the article. Curses of generated electrodynamical force against displacement of coil - valve assembly has been computed using FEM method and presented in the article. The courses of valve lift against time for different conditions have been presented in the article.

The main inlet component of steam turbine is control valve. The stable operation of the steam turbine control valve is vital for safe and stable operation of the steam turbine and safety production of the power plant. However, due to the complexity of the structure and unsteady characteristics of steam flow in the valve, there is not enough experimental method about the detailed flow characteristics of the area near control valve disc and the inside of the valve chamber up to now. This article is to focus on the simulation of the steam turbine control valve interior flow field which includes the valve pre-inlet channel in different conditions, then find the reasons which caused instability and pressure loss of the control valve by analyzing the flow field details, finally further optimization design. The profile matching of the valve disc and valve seat has a great influence on the interior flow field of control valve, so analysis of the high performance valve disc shape and divergence angle of valve seat is carried out, and the research conclusion is used for guide design and development of the control valve.

The three element drive pump failure was the main reason to reduce inspection cycle of the pump. In this paper, a law of pump valve motion in one stroke was acquired through the establishment of the motion equations of the pump valve in the oil well pump, by making it as the pump valve boundary conditions and using ANSYS / LS-DYNA software, the stress state of the valve housing under the conditions of pump valve impact on the valve cover was analyzed, and as the calculation was shown, under the same conditions, the groove valve cover has the stronger impact than the extended grooved valve housing. The inspection cycle of groove valve housing was 457 days shorter than the extended grooved valve cover according to the theory of the fatigue life, therefore, the extended valve housing can effectively extend the check period.

Hydraulic control one-way valve as the retaining element of vertical hydraulic cylinder, often is due to improper application to produce large opening pressure, not unlocking, vibration, noise etc.fault. This paper analyses two vertical hydraulic balance circuit, one makes use of the one-way throttle valve and another is not,calculates the necessary condition and opening pressure of hydraulic control one-way valve reverse opening, obtains the opening characteristic of hydraulic control one-way valve in vertical balancing circuit, acquires the relationship of the reverse opening pressure with hydraulic cylinder balance pressure, hydraulic cylinder speed ratio, hydraulic control one-way valve structural parameters. Lastly, how to correctly use the hydraulic control one-way valve is discussed in the vertical hydraulic cylinder balanced circuit.

MAN Diesels 6S50MC-C disel is a two-stroke marine diesel engine. Preload of the exhaust valve component is applied in four bolts. The preload of bolts can improve the fatigue strength of the exhaust component. In addition, the bolt pretension ensure the sealing in the maximum firing pressure. Using of simulation method, the displacement and deformation of exhaust valve component are analyzed when the maximum firing pressure and preload are applied. By analysis of the deformation of the exhaust valve housing under different preload force, the deformation of exhaust valve housing increase with the increaseing of preload. The maximum total deformation is 0.40mm in the preload of 720KN. The maximum deformation occurs in the region near the bolt in the side of exhaust gas outlet. The deformation in the direction of Y-axis of exhaust valve housing is along the Y-axis opposite direction when the preload is greater than 540KN. This indicates that the exhaust valve seal well. The sealing and deformation of the exhaust valve component meets the desgin requirement.

With the application of FLUENT, in the inner flow field of the non-circular opening spool valve, the three-dimensional steady-state model was simulated at different valve port opening. The numerical simulation and visual analysis of the aboved flow field was carried out. In the valve port, the mass flow simulation value was compared with the calculated value. Then the relations of the valve opening size and speed, pressure and valve port flow characteristic of the flow field could be abtained. This method is helpful of analysis to different valve port structures, and plays an important role in the improvement of hydraulic valve performance.

This paper introduces new type of save energy piston valve for water pump balance control, which is save energy efficiency expert. This piston valve is designed by pneumatic theory, and drive power is delivered by air compressor or pressure air source in waterworks. Pressure air is lead into cavity of piston valve by transfer action of “two positions and five channels ” electromagnetic valve, then piston drive valve to open or close water pump. This piston valve has followed functions such as balance control action, avoiding refluence, zero flow open and close, accidental power stop for water hammer and son on. Application of this piston valve had proved saving energy to 3%.

The valve plate of the hot blast valve is to rely on itself spiral waterway to cool. In the course of actual use, there is uneven actuality that it is cold and hot for the Valve plate of the hot blast valve. In this article, by means of COSMOSFloworks software, based on classic formula for convective heat transfer of heat transfer, we do flow field analysis for the waterway of the valve plate of DN1800 hot blast valve for certain Heavy Industry Group of our country. And analytical result indicates: Uneven distribution of water velocity in the valve plate is an important reason for causing unequal heat exchange of the valve plate and local thermal shock. In order to improve cooling uniformity, the central flow state of the type valve Plate should be altered and water cooling structure of inner water ring edge should be widen, finally the increase of the life of the valve plate can be reached.

Working state of compressor valve plays a key role in compressing. Valve plate opening not timely or even chattering is a major problem in the process of air passed into the cylinder. This paper through the improvement of valve seat to increase the pressure exerting on the valve plate then to reduce or even to eliminate the phenomenon mentioned above is a good try. With the help of software to do simulating calculation of flow field for the contrastive models of the seat channel, proved that the improved structure achieves the goal designed. This may provide a new way to the valve improving designation and make certain significance in practice.

The difficulty of measuring the run-out of engine valve seat related to the centerline of the valve guide is the determination of the datum axis. A method that the gauge was fixed on the conical surface of the valve seat was chosen. One sensor on the conical surface of the gauge measures the run-out of the valve seat related to the centerline of the gauge. Another two sensors of the gauge measures the centerline of the valve guide. The mathematic model of measurement is established, the run-out of the valve seat related to the centerline of the valve guide can be archived.

Distributing valve is the key component of underwater hydraulic breaker, and the theoretical analysis of it is very necessary. Through the flow analysis of the conical valve core, the cone angle of the conical valve core has been determined, the design parameters of distributing valve have been verified. According to the force balance equation of the conical valve core and distributing valve core, the corresponding simulation research and analysis have been done for this distributing valve, the rationality of the design has been further verified. According to the knowledge of hydraulic breaker, valve mouth flow and force analysis, the various analysis and validation of distributing valve of breaker have been done, the rationality of design has been checked, and the analysis method can be adopted in studies of this area.

Hot-air valve can be easily ineffective during the operation due to the bad influence of the eddy heat on the bottom outer-edge of the valve plate. COSMOSFloworks software was used to analyze the flow field of DN1800 hot-air valve duct in a certain domestic company, by adopting the classical formula of heat transfer theory’s convective recuperative system as reference. The analysis results showed that during the beginning opening of hot-air valve duct, the bottom outer-edge of valve plate receive the influence that the hot-air enforce convection heat exchanger, while during the late opening of hot-air valve duct , the bottom outer-edge of valve plate receive the influence of eddy heat exchange. Based on this analysis , the paper suggests the measures which bring down the temperature of outer-edge of valve plate .

Lubrication and sealing are the key research points in water hydraulic technology. A better seal is provided by the structure form of the poppet valve comparing to the spool valve, however, poorer linearity and control accuracy accompanies inevitably. Aiming at improving the control performance of poppet valves, the design of the water hydraulic digital valve is analyzed in this paper. A high speed digital valve is designed and controlled by PWM (Pulse-Width Modulation) and actuated by a piezoelectric ceramic stack with high frequency response and control stiffness. Another new design using poppet valves for digital bits is proposed to ensure enough seal ability and lower the cost of the valve, namely the multi-digit on-off valve. The simulation models of these two types of valves are built and the results show the different performances between the valves. The high speed digital valve is provided with high control accuracy and responsiveness. In contrast, large overshoot and oscillation are encountered during switching on the digits of the multi-digit on-off valve. Especially the switching process of the high digital bits requires to be regulated to reduce the large overshoot. The above analysis contributes to the improvement of lubrication and sealing in water hydraulic control valves and applications of water hydraulics in the industry.

The operating principle of cartridge valve controlled by high-speed on/off valve is expounded, the mathematical models are established on the basis of the principle. The simulation model of system is created in AMEsim. By analyzing the curve charts of spool’s displacement and outlet flow rate of cartridge valve, the PWM signal frequency and duty cycle have influences on the control performance of cartridge valve controlled by high-speed on/off valve are concluded. The results show that the cartridge valve can be got good linear control when the input signal is low- frequency and moderate duty cycle.

Though statistically analyzing ten typical wells of kelly cock valve failure in certain oilfields, the main failure modes of the kelly cock valve were determined. Aiming at these modes and combining with mechanical analysis of knob, upper seat and main body of the kelly cock valve, its finite element calculation had been implemented and the weakness of all parts was found. By numerical modeling of the flow field of a kelly cock valve it was found that the velocity of fluid rapidly increased at upper and lower valve seats and this could easily prick out ball valves and valve seats, there was a annular low-velocity zone of minimum speed between the ball valve and the inner wall of the main body and this caused solid aggregation at this area. The research in this paper made the modes and causes of kelly failure to be recognized systematically. The results provided theoretical foundations of further improving the design and reasonable using of a kelly cock valve.

When designing motorcycle engine, engine cylinder head abnormal noise is common, and difficult to eliminate due to thermal expansion and contraction of the aluminum alloy cylinder head. In this study, on the basis of dynamic change with the performance of 157FMI engine in hot and cold, the reasons for engine cylinder head abnormal noise are analysed, and valve plunger with variable length is applied to minimize the valve clearance, and to make the valve clearance of engine in cold and hot zero, and thus the noise problem of cylinder head with 157FMI engine in hot is completely eliminated.

Water hydraulic servo valve has become an important research subject nowadays, and its secondary amplifier usually uses slide valve. Research on flow characteristics of water hydraulic slide valve is important to the design of water hydraulic servo valve. Based on the classical theory of incompressible flow, CFD software FLUENT is used to simulate and analyze the flow characteristics of water hydraulic slide valve. Simulations with different boundary values are applied to the same slide valve in order to guarantee the accuracy of the simulation results. Detailed comparisons are made between throttles with different structure parameters, including spool diameter, spool opening, flow passage diameter and equalizing slots so as to define the parameters respectively. The results indicate that the flow rate of the slide valve designed is approximately proportional to the spool opening within certain travel. Finally, the structure parameters of the slide valve that satisfy the design requirements are obtained. The simulation results provide theoretical basis for the design and improvement of water hydraulic slide valve used in water hydraulic servo valve.

Small Butterfly valve is specially designed for use in industry field and ship. The important parts of butterfly valve are composed of disk, stem and body. But, like LNG ship, in enviroment of low temperature, as working condition deteriorates, important of sealing more increased. In this study, we examine sealing mechanism of butter valve on the base of FEM and investigate sealing life by measurement. The finite element analysis was carried out to study the effect of the seal ring shape on bi-directional sealing force of valve. The sealing mechanism was evaluated by 2-dimensional model in order to save the analysis time. And these analyses used by material non-linearity and contact element were implemented.

The introduction of ceramic particulate into metallic powder will unavoidably lower the compressibility and formability of the mixed powder. In order to overcome these problems, in this study, warm compaction was introduced in the forming of an NbC particulate reinforced iron-base valve-guide cup, which is used in a combustion engine. Warm compaction was used not only because it can provide compacts with high green density but also it can increase the formability of the mixed powder. The part composed of an iron-base material which possesses 10wt%NbC with a relative density of 97.7%, a tensile strength of 815MPa, an elongation of 1.5%, a hardness of HRC33 and an impact toughness of 11J/cm2. Its working surface composed of an iron-base material which possesses 15wt% NbC with a high relative density of 98.2%, a tensile strength of 515MPa, a hardness of HRC 58 and a remarkable tribological behavior. The sintered part successfully passed a 500 hours bench test. No serious wear on the working surface can be observed after the test. Results indicated that the sintered part has excellent wear resistivity and the NbC particulate reinforced iron-base composite is a suitable material for parts that work under severe wear condition.