Internal Combustion Engine Piston Research Articles

Hydraulic free piston internal combustion engine. Outline of the fundamental test apparatus with opposed pistons.

A fundamental test apparatus of the hydraulic free piston internal combustion engine, whose pistons stop after every gas cycle, is constructed and tested. To eliminate the vibration of the system, an opposed-piston construction is used in this experiment. Other features of the test apparatus are fuel injection, compression ignition, uniflow scavenging, two-stroke cycle and single cylinder. For intermittent operation, a high-performance pilot-operated hydraulic check valve is necessary, and a newly designed and constructed valve is used in this test. The synchronization of the opposed pistons is achieved by positioning both pistons at mirror positions before the start of the gas cycle; no mechanical cynchronization system is employed. The test apparatus performs satisfactorily, and intermittent operation, stopping after every gas cycle, is realized.

Hydraulic free piston internal combustion engine. Experimental investigation on the fundamental test apparatus with opposed piston.

The test results on the dynamic behavior of the free piston displacements, the hydraulic pressures and the gas pressure on the first cycle at the start of the engine at room temperature are reported in this paper. It becomes clear that the entire cycle consists of four processes, that is, the compression, expansion, bounce and damped oscillation processes. Dynamics of the free piston in these four processes are discussed in this paper. Furthermore, the value of the polytropic index on the compression process is obtained experimentally. The energy losses in the compression process are also discussed in this paper. It becomes clear that the main sources of energy losses are piston friction and pressure loss in the pilot-operated check valve. Finally, the firing operation is repeated every 0.5 or 1.0 second, and the free pistons stop after each operation.

Planetary-Gear-Type Second-Harmonic Balancers

This paper describes several mechanical balancers, based on the planetary gear trains known as the hypotrochoid and epitrochoid trains, for reducing or eliminating second-order out-of-balance in mechanical systems. It is shown that by proper arrangement of the planetary gear trains, a balancer can be obtained for the elimination of second-order shaking forces or second-order shaking moments or a combination of both shaking forces and moments. The advantage of this type of balancer is that the carrier of the gear train needs only to run at the primary speed of the mechanical system to be balanced. Therefore, the balancer can be designed to be concentric with the primary rotating shaft of the machine using the primary shaft as the carrier. For example, for the balance of the second-order shaking force of an inline four-cylinder four-stroke internal combustion piston engine, the balancer can be placed on the third main bearing or one on each of the second and fourth main bearings.

4776075 Method for manufacturing piston of internal combustion engine : Yasuhiro Kawabata, Naoki Minamoto, Soichi Hara, Takanori Kamiya, Anjo, Japan assigned to Aisin Seiki Kabushiki Kaisha

4776075 Method for manufacturing piston of internal combustion engine : Yasuhiro Kawabata, Naoki Minamoto, Soichi Hara, Takanori Kamiya, Anjo, Japan assigned to Aisin Seiki Kabushiki Kaisha

Internal combustion piston engine using air chamber in piston driven in resonance with combustion wave frequency

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Low-noise level reciprocating piston internal combustion engine

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A method for evaluation of elliptical profiles

Measurement and evaluation of circular profiles of cylindrical components in terms of circularity has been well established using roundness measuring instruments. For elliptical sections having very little difference between the major and minor diameters this difference can be measured with the roudness measuring instrument. However, fitting of the best fit ellipse and hence the definition of ellipticity are not available. Applications of elliptical profiles include instruments, such as the photospectrometer developed at CMTI with accurate elliptical cams, elliptical gear blanks, and the pistons of internal combustion engines whose cross sections are elliptical. In this paper a method for the evaluation of the elliptical profiles for centre and orientation of major and minor axes is described and two concepts for defining ellipticity are discussed

Characteristics of a closed Brayton cycle piston engine

A closed Brayton cycle piston engine could use any high- or low-grade fuel, including unprocessed biomass or coal. Potential applications include small stationary power plants, and engines for vehicles. As a step toward assessing the feasibility of such an engine, calculations are described which allow one to compare the closed Brayton engine to an internal combustion (I.C.) piston engine with regard to efficiency, power per unit displacement, peak cylinder pressure, and coolant loading. As part of the calculations, mechanical efficiency, valve losses, and optimum pressure ratio are determined using methods developed for I.C. engines. It is shown that efficiency and power density are comparable to those of an I.C. engine, while pressure and coolant load are well within the range encountered in an I.C. engine.

Evaluation of the thermal and stress-strain state of an internal combustion engine piston by the finite-element method

1. The use in piston design for some axisymmetric sections by the equal stiffness and thermal conductivity method with plane design layouts and fictitious heat sources makes it possible by means of relatively simple programs to perform analysis of the thermal and stress state of a hopped-up internal combustion engine piston. 2. Calculated results are in good agreement with the nature of crack formation in pistons during operation.

Choice of optimum design for an internal combustion engine piston

Choice of optimum design for an internal combustion engine piston

Means of specifying hydrocarbon composition and distillation curve of fuels for internal-combustion piston engines

Means of specifying hydrocarbon composition and distillation curve of fuels for internal-combustion piston engines

Seals for rotary regenerative heat exchangers

The gas turbine is the prime alternative to the piston internal combustion engine as a power unit for road vehicles. The basic principle of the turbo-jet and its adaption by a power turbine to provide shaft power is well-known. The automotive gas turbine (Fig 1), because of its small size and the economics of its manufacture, operates at low compression. For good cycle efficiency at a turbine inlet temperature of 1050°C, it must be provided

Strength of the materials used for pistons of internal-combustion engines on subjection to fatigue and thermal fatigue loading

1. The strength characteristics of the piston alloys under consideration, measured under conditions of isothermal and thermal fatigue approaching those encountered in actual practice, are considerably lower than the static strength characteristics. This indicates the importance of allowing for the factors in question when calculating the strength of interual-combustion-engine pistons. 2. Of the alloy studied in the present investigation, the lowest thermal-fatigue strength characteristics corresponding to approximately normal working conditions are those of aluminum alloy AL25. For temperature cycles of 55⇌330°C the breaking stress on a base of 2·104 cycles of heat exchangers falls to 1 kgf/mm2, as compared with the isothermal fatigue limit (6.1 kgf/mm2) and the static tensile strength (12 kgf/mm2) at the same temperature. 3. Under conditions of combined loading, the fatigue life of alloy AL25 falls more rapidly than would follow from the linear hypothesis of damage summation, allowing for both mechanical and thermal fatigue. A vital factor in this case is the damage associated with interaction between the fatigue and thermal fatigue processes due to multiple-factor effects. 4. Criteria for the failure of piston materials under multiple-factor conditions call for urgent and more extensive investigation.

Motor oil consumption in internal-combustion piston engines (a discussion)

Motor oil consumption in internal-combustion piston engines (a discussion)

Temperature measurements of internal-combustion engine pistons

Temperature measurements of internal-combustion engine pistons

内燃機関用ピストン合金, AC8Aの強度に及ぼす高温保持時間の影響

内燃機関用ピストン合金, AC8Aの強度に及ぼす高温保持時間の影響

LUBRICATION PROBLEMS IN ROAD TRANSPORT

MOST modern internal combustion piston engines when under power have such a contented purr that many people contend that no serious lubrication problems of a technical variety remain to be solved, and that the only problems worth mentioning are those which are solely of an economic nature. Such views are, in their own way, flattering to the oil manufacturer who has striven hard, in conjunction with engine manufacturers, to bring these engines to a high pitch of reliability in a relatively short time. However, complacency in a world of change can be a dangerous thing.

Aircraft Propulsion

Mechanical flight began just over 40 years ago, and the only system of propulsion in use until five years ago was the internal combustion piston engine driving a propeller. Quite suddenly, the internal combustion turbine has come very much to the fore, both with and without a propeller, giving an increase in speed from under 500 to over 600 m.p.h.—a result chiefly due to the great increase in thrust horse-power available from a given weight and bulk of power plant. In much the same way as Parsons's demonstration of the possibilities of the steam turbine in the launch Turbinia eventually established the steam turbine as the chief prime mover for large powers, so the record-making Meteor has begun a similar change-over in aircraft propulsion, and perhaps in power plant for locomotives, ships, and power stations. The piston engine, however, has taken 40 years to reach its present development from the rather crude early motor-car engine, and doubtless it will be a long time before it becomes obsolete. It seems a suitable time to put on record the progress in power to weight ratio, reliability, and thermal efficiency that has been made possible by intensive development and research.

Y合金の時効硬化に就て

Y-alloy contains Cu 4%, Mg 1.5%, Ni 2% and Al remainder. It is heat-heated and used for piston and cylinder head of internal combustion engine. Its Age-hardening phenomenon is similar to that of 24 S-type super-duralumin. From the constitutional diagram of the Al-Cu-Mg-Ni system, the age-hardening of such an alloy as Y is explained by the precipitation of a ternary compound of Al-Cu-Mg system termed “S” by the author. It is ascertained by the change of dilatation of the quenched specimen on tempering. Si must not be contained in Y-alloy, for it is detrimental to its age-hardening. If Si is contained above a certain percentage, the equilibrium relation of the alloy is displaced to the domain, where S-compound does not separate from the Al-solid solution.