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The present attempt in this project is to reduce the vibrations, temperature due to friction, noise and weight of I C engine valve guide by replacing conventional metal valve guide with composite valve guide. Composite materials have been used in automotive components because of their properties such as low weight, high specific stiffness, corrosion resistance, ability to produce complex shapes, high specific strength and good impact energy absorption etc. The Internal combustion engine valve guides are the parts that support the valves in the cylinder head, besides this it keeps lubricating oil from getting sucked into the combustion chamber past the intake valve stem, it keeps exhaust gases from getting into the crankcase past the exhaust valve stem and it also keeps the valve face in perfect alignment with the valve seat. A valve guide test rig is indigenously fabricated. Valve guides are manufactured using the developed composite material (Resin ARL-136, Hardener AH-126 and 4 vol% WS2), on a CNC lathe. The performance of the developed composite guide under varied conditions of speeds, that is, fixed change in rpm and modulated changes in rpm is assessed. Noise, temperature and vibrations are measured. The experimental data revealed that contribution of composite guide in respect of acceleration, velocity and displacement components of vibration is not substantial. A substantial reduction in noise levels is seen. As far as temperature rise due to friction is concerned maximum components fail at elevated temperatures, with composite guides the temperature generated due to friction at higher speeds is less, a considerable weight reduction is also observed.

In practice, economical reaming of precision holes requires the use of multi-blade reaming tools. The main objective of precision machining processes is to minimize any deviations arising from dimensional and shape tolerances. However, process errors such as misalignment errors between the axes of the tool and the pre-drilled hole can occur during reaming processes, thus affecting the machining outcome. This experimental study aims to investigate the influence of process errors and tool geometry on the resulting hole quality while reaming valve guides made of sintered steel alloys. There is particular emphasis on the guiding function of reaming tools with regard to varying chamfer dimensions and back taper ratios at the secondary cutting edge. The experimental results indicate that an enlarged contact zone between the secondary cutting edge and the workpiece material will lead to improved straightness tolerances.

Valve seats press-fitted in the cylinder head function to hold exhaust gas inside the ignition chamber and to transfer heat to the coolant moving in the water jacket of the head. The press-fitting of the valve seats to the head at ambient temperature has been widely spread out due to its many advantages over pressing with frozen valve seats or with a heated head. The benefits include lower equipment costs, lower running costs, and fewer installation faults during the press-fitting. Nevertheless, a systematic approach for pressing at ambient temperature (ATP; ambient temperature press-fitting) has not been studied and analyzed to date. A technique to check the reliability of the press-fitting by measuring hoop strain inside the valve seat and the FEM procedure to simulate ATP is developed in this study. The FEM procedure of ATP developed here exhibits a concurrence with experimental results. Utilizing the DOE (Design of Experiments) technique, we determined the effects of various geometric parameters and the optimal shapes of the valve seat and cylinder head. The optimal shapes have been successfully applied in an actual engine and varified in a running-engine test.

Seat tightness at the fully shut position should be a consideration in the development of a butterfly valve for use in a liquefied natural gas (LNG) vessel. A flexible solid metal seal offers sufficient tightness of the butterfly valve and meets the specifications for cryogenic temperature. In the present study, characteristics for a cryogenic butterfly valve, such as the flow coefficient and the pressure loss coefficient, were estimated by numerical fluid analysis carried out to simulate 3-D flow and to study performance as it was affected by the opening angles of the valve disc. A design criterion to ensure the seat tightness of the butterfly valve at the fully shut position was proposed, in which the contact pressure between the metal seal and the valve disc would be compared with the fluid pressure. Numerical structural analysis showed that the contact pressure can be calculated by simulation of the frictional contact behavior on the surface of the metal seal and the valve disc. As a result, an adequate flexibility of the metal seal and the valve disc was required in order to accomplish a contact pressure that would be high enough to satisfy the seat tightness requirement. Under cryogenic temperature, thermal shrinkage caused the metal seal to adhere closely to the valve disc periphery at both sides and raised the contact pressure to a relatively high value, though there was no contact across a small area at the center position, which is susceptible to leakage. An additional displacement of the metal seal and the valve disc appeared at an operating fluid pressure of 6.9 bar and produced sufficient contact pressure at the no-contact area. This was verified by experimental leakage tests performed at room and cryogenic temperatures.

Composite materials are replacing the materials used in various fields and are the candidate materials for future growth. Metal matrix composites are the class of composite materials finding vast applications in automotive, aircraft, defense, sports, and appliance industries. In the present work, Al–SiCp composites with 5–30 wt.% of SiC particulates were fabricated using powder metallurgy as well as casting processes. Mechanical alloying of aluminum and SiC particles was done prior to compaction so as to enhance the properties of the fabricated powder metal components. A custom built sliding valve guide wear test rig was fabricated to simulate the valve stem/guide wear under cold start condition of an engine by reciprocation of a valve stem under different imposed loads, against a stationary poppet valve guide. The hardness and radial crushing load was measured for the Al–SiCp composite poppet valve guides and were found better than the cast iron poppet valve guides presently used in engines. The wear test of the poppet valve guides was done using valve guide wear test rig, which revealed that the Al-20 wt.% SiCp and Al-30 wt.% SiCp composite poppet valve guides have higher wear resistance than the cast iron poppet valve guides. The hardness, radial crushing load, and wear resistance of Al–SiCp composite poppet valve guides were found to increase with increase in weight percent of SiCp. The microstructural analysis of the cast and PM Al–SiCp composites was also done using scanning electron microscope. Finite element analysis of the Al–SiCp composite poppet valve guide was also done using Ansys software, which supports the successful implementation of the Al–SiCp composite poppet valve guides for automobiles.

Pump valve test data are used in a new design of valve unit with a spherical self-adjusting surface in the body of the upper guide sleeve, which provides an increasing working life.

Tribologtcal characteristics in the sliding parts of oil hydraulic piston pumps are very important in increasing overall efficiency In this study, the fluid film between the valve plate and the cylinder block was measured by using a gap sensor and the mercury-cell slip ring unit under real working conditions To investigate the effect of the valve shape, we designed three valve plates each having a different shape One of the valve plates was without bearing pad, another valve plate had bearing pad and the last valve plate was a spherical valve plate It was noted that these three valve plates observed different aspects of the fluid film characteristics between the cylinder block and the valve plate The leakage flow rates and the shaft torque were also investigated in order to clarify the performance difference between these three types of valve plates From the results of this study, we found that the spherical valve plate estimated good fluid film patterns and good performance more than the other valve plates in oil hydraulic axial piston pumps

The tribological mechanism between the valve plate and the cylinder block in oil hydraulic axial piston pumps plays an important role on high power density. In this study, the fluid film thickness between the valve plate and the cylinder block was measured with discharge pressure and rotational speed by use of a gap sensor, and a slip ring system in the operating period. To investigate the effect of the valve plate shapes, we designed two valve plates with different shapes : the first valve plate was without a bearing pad, while the second valve plate had a bearing pad. It was found that both valve plates behaved differently with respect to the fluid film thickness characteristics. The leakage flow rates and the shaft torque were also experimented in order to clarify the performance difference between the valve plate without a bearing pad and the valve plate with a bearing pad. From the results of this study, we found out that in the oil hydraulic axial piston pumps, the valve plate with a bearing pad showed better film thickness contours than the valve plate without a bearing pad.

A force model of a control valve of injector is set up, and the changes of the fluid damping clearance are investigated on the basis of the results of the computational fluid dynamics (CFD) and the experiments of control valve of injector. Results indicate that a damping clearance of 0.02–0.03 mm between the poppet and the valve guide is the most sufficient to dampen any excessive control valve poppet bouncing.

1. The optimum conditions for sintering 8.0–8.5-kg boat loads of valve guide bushings may be taken to be a temperature of 1160°C and a boat pushing period of 20 min. 2. Carbon segregation along the bushing height leads to instability of strength properties. 3. The material of bushings from PZh2M2 powders surpasses in physicomechanical properties that of bushings from PZh2M3 powders. 4. Nonuniform compaction, resulting in increased porosity in the central part, has an adverse effect on the strength properties of bushings, even when the latter's over-all porosity is of the order of 20% (which meets the requirements of TU 02-69 specification for valve guide bushings). When one-fifth or two-fifths of a bushing at either end has a higher porosity, the strength of the bushing remains unchanged. 5. In an investigation of the temperature distribution in an OB-357 furnace during the sintering of bushings, it was established that, when the operation is performed with a 20-min period at 1160°C, sintering temperature is maintained over three boat lengths, which ensures an optimum sintering time, 1 h, and imparts satisfactory strength to bushings. 6. A study was made of the dimensional changes of bushings from PZh2M2 and PZh2M3 powders under various sintering conditions. A knowledge of these changes is indispensable in die calculations if parts of the required degree of dimensional accuracy are to be produced.