Cylinder Head Gasket Research Articles

Flat gasket, especially cylinder head gasket

Flat gasket, especially cylinder head gasket

New cylinder head gasket concept for the BMW six cylinder twin turbo gasoline engine

The new BMW in-line six cylinder gasoline engine once again sets standards in innovative engine development. The demands on the cylinder head gasket are correspondingly challenging and complex.Using the hitherto less widely known BOSTEC gasketing concept from Federal-Mogul Sealing Systems in conjunction with proven FEA design methodology, an optimally tailored cylinder head gasket was successfully developed for production application on this engine in a very short space of time.

Metal layer cylinder-head gaskets with coined stoppers

With the development of coined stoppers, ElringKlinger has launched the third generation of Metaloflex metal layer cylinder-head gaskets on the market. In addition to meander and honeycomb stoppers, the newly introduced segment stopper now provides the optimum solution for every installation thickness and application. This system is not only more efficient economically but also offers further crucial advantages for modern engine designs: The available bolt load is utilized more efficiently thanks to the consistent topographic design of the gasket. This enables the component deformation in the cylinder head and block to be reduced further while additionally increasing the sealing potential of the gasket despite increasingly critical basic conditions.

Cylinder head gasket with integrated sensor

Cylinder head gasket with integrated sensor

Patent review for 2005 – even more inventions during the year

The number of patents reviewed that were published during 2005 was a significant increase over the previous two years that we have carried out this review. Comparison with 2003 and 2004 shows an increasing interest in cylinder head gaskets, bearing seals plus other lip seals applications, and also in turbomachinery sealing. But the biggest increase from previous years has been in the number of patents for pipe fittings, mostly for building services and utility pipelines. The most common trend across all industries is the claims for improvements to manufacturing and convenience of assembly.

ディーゼルエンジンのＰｍａｘ上昇によるヘッドガスケットシーリングへの影響とその対応

The maximum combustion pressure (Pmax) tends to increase in a diesel engine. This leads to the cylinder head gasket sealing being exposed to tough conditions which can result in gas leakage. In this study, the main factors affected by the rise in Pmax are analyzed and also from perspective of treatment orientations not only for cylinder head gasket but also total sealing engine are proposed.

Cyclic variations of fuel-droplet distribution during the early intake stroke of a lean-burn stratified-charge spark-ignition engine

Lean-burn spark-ignition engines exhibit higher efficiency and lower specific emissions in comparison with stoichiometrically charged engines. However, as the air-to-fuel (A/F) ratio of the mixture is made leaner than stoichiometric, cycle-by-cycle variations in the early stages of in-cylinder combustion, and subsequent indicated mean effective pressure (IMEP), become more pronounced and limit the range of lean-burn operation. Viable lean-burn engines promote charge stratification, the mixture near the spark plug being richer than the cylinder volume averaged value. Recent work has shown that cycle-by-cycle variations in the early stages of combustion in a stratified-charge engine can be associated with variations in both the local value of A/F ratio near the spark plug around ignition timing, as well as in the volume averaged value of the A/F ratio. The objective of the current work was to identify possible sources of such variability in A/F ratio by studying the in-cylinder field of fuel-droplet distribution during the early intake stroke. This field was visualised in an optical single-cylinder 4-valve pentroof-type spark-ignition engine by means of laser-sheet illumination in planes parallel to the cylinder head gasket 6 and 10 mm below the spark plug. The engine was run with port-injected isooctane at 1500 rpm with 30% volumetric efficiency and air-to-fuel ratio corresponding to both stoichiometric firing (A/F=15, Φ =1.0) and mixture strength close to the lean limit of stable operation (A/F=22, Φ =0.68). Images of Mie intensity scattered by the cloud of fuel droplets were acquired on a cycle-by-cycle basis. These were studied in order to establish possible correlations between the cyclic variations in size, location and scattered-light intensity of the cloud of droplets with the respective variations in IMEP. Because of the low level of Mie intensity scattered by the droplets and because of problems related to elastic scattering on the walls of the combustion chamber, as well as problems related to engine “rocking” at the operating conditions close to the misfire limit, the acquired images were processed for background subtraction by using a PIV-based data correction algorithm. After this processing, the arrival and leaving timings of fuel droplets into the illuminated plane were found not to vary significantly on a cycle-by-cycle basis but the recorded cycle-by-cycle variations in Mie intensity suggested that the amount of fuel in the cylinder could have been 6–26% greater for the “strong” cycles with IMEP 115% higher than the average IMEP, than the ones imaged for “weak” cycles at less than 85% the average IMEP. This would correspond to a maximum cyclic variability in the in-cylinder equivalence ratio Φ of the order of 0.17.

Cylinder head gaskets for the new Al/Mg composite construction of BMW gasoline engines

The newest generation of the BMW inline six-cylinder engines is ready for market launch. The sealing manufacturer Victor Reinz, engineering partner and series supplier of the international automobile industry, has made a significant contribution with his new design of a cylinder head gasket. The five-layer gasket was adapted to the aluminum/magnesium composite construction of crankcase of this engine.

Numerical calculations for seals and components

Numerical calculations and simulations are used for example to adapt the vertical distribution of stoppers in cylinder head gaskets to suit modern engines. This article by Freudenberg Dichtungs- und Schwingungstechnik KG, Weinheim, Germany, shows the advantages of this method for the development of cylinder head gaskets and other parts.

Integrated pressure sensor systems in the cylinder-head gasket

The optimisation of engine management plays a major role in the development of modern engines. A significant contribution to this optimisation will be made by a cylinder-head gasket with integrated pressure sensors of the quality required to measure in-cylinder pressure, which ElringKlinger AG together with Kistler Instrumente AG are currently working on. The goal is to provide the automotive industry with a system that makes it possible to optimally control combustion in each individual cylinder.

Cylinder head gasket with wide stopper

Cylinder head gaskets featuring wide stopper technology from Freudenberg Meillor are not only the optimum solution for the seal contact area between the cylinder head and engine block, they also allow for a targeted reduction in joint gap vibration. The stopper distributes the forces that are required for sealing more evenly around the combustion chamber and therefore at a lower level.

Enhanced functionality for cylinder head gaskets

In numerous production ramp-ups, the Wave-stopper has shown that it offers numerous design and functional advantages in modern engines. The gasket adapts perfectly to the given clamping, temperature, and stiffness conditions, making optimum use of the available space. Recognizing the versatility of this sealing component, Victor Reinz is consistently pushing its advanced development. Meanwhile, the new technology is being applied with great success in combination with single- or multi-layer steel (SLS, MLS) cylinder head gaskets for diesel and gasoline engines of all power ratings.

Patents

Sealing a gap on a roller strip casting machine Repairing an aircraft door pressure seal Liquid seal for a wet roof bit Seal for a cable entry or pipe penetration Notched blade seal for high performance aircraft Piston seal Dynamic end seal for image forming apparatus Rearward wash basin with neck seal Gap seal for injection moulding apparatus Premixed and frozen seal caps Cylinder head gasket

The brazing of nickel-based brazing alloys using advanced application techniques

The use of Braze-Skin technology for applying nickel-based brazing alloys by spraying and screen printing techniques is an advantageous alternative to existing melt-spin films, brazing alloy tapes and brazing alloy pastes. The first applications are currently being used for large-volume manufacturing or are being prepared for such use. These include, for example, cylinder head gaskets, plate heat exchangers and EGR coolers.

Metallic flat joint for cylinder head gaskets

Metallic flat joint for cylinder head gaskets

Topographic stopper for cylinder head gaskets

More than half of all current cylinder head gaskets have a so called stopper zone around the combustion chamber. This design element ensures a durable sealing pressure in all operating conditions and increases the fatigue strength of functional layers in multi-layer steel gaskets (MLS). Primarily the continuing trend towards diesel engines and the overall increasing demands of engine operation ask for new stopper design solutions. Federal-Mogul has explored and compared existing stopper types. The results led to the development of the laser welded, topographic stopper. Gaskets with this stopper technology have been presented to a large European vehicle manufacturer and are now in the advanced phase of engine testing.

Cylinder head gaskets with integrated temperature sensors

The primary task of conventional cylinder head gaskets is to provide a reliable seal. The new SensoriCS® head gaskets from Victor Reinz with integrated temperature sensors use the excellent locations in the immediate vicinity of the combustion chambers for temperature measurement, whereby the measurement signals from inside the engine are taken directly to the outside. Highly dynamic signals allow an optimum adaptation of the cooling media flow to the prevailing engine conditions. This leads to higher engine efficiency, reduced fuel consumption, and lower exhaust emissions during the warm-up phase as well as normal operation. Another important advantage lies in the fact that the sensors are installed in the engine during the normal process of mounting the head gasket.

An experimental study on the dynamic characteristics of cylinder head gaskets for diesel engine: dynamic characteristics in heating and cooling temperature cycle by abrupt change of water during steady operation

Experiments on a small, one-cylinder high-speed diesel engine were performed by changing the temperature of cooling water and also by changing the material and configuration of the cylinder head gaskets. Three kinds of cylinder head gaskets were made. The temperature was abruptly changed and the temperatures at several points of the cylinder head gasket and its peripheral region, the relative displacement between cylinder head and cylinder block, the loads of the cylinder head bolts, the indicator diagram, the pressure of gasket surface and combustion gas leakage were measured. The sealing characteristics in the transient state and the steady state of the cooling water temperature were investigated from an experimental standpoint. The effect of the temperature differences between the cylinder head, cylinder block and head bolts on the loads of the head bolts and the relative displacement between the cylinder head and cylinder block were observed for the test gaskets.

Cylinder head gasket and armour rings

Cylinder head gasket and armour rings

Computations of an engine to analyze cylinder distortion

The aim of the research work presented here is to control the geometric distortions of engine cylinders, which involve both noise and oil consumption. The final goal is then to limit pollution from engines. The simulation deals initially with the cold stamping and crushing operations of a cylinder head gasket; based on using solid finite element models from the Abaqus computer code (version 5.3) for large deformation with plasticity and contact, including friction. In addition, experiments have been carried out to identify the plasticity rule for the materials used in order to simulate the crushing of the cylinder head gasket under a given normal pressure representing the clamping operation. The main difficulty of this work is to correlate the cylinder head gasket behaviour and cylinder distortions with the main function of the gasket, i.e. pressurized gas sealing. The cylinder head gasket is a complex multilayered structure made of three spot welded metal sheets. This assembly has many holes of different shapes. Around the cylinder hole on both outer layers of the gasket, there is a small size embossment to ensure gas sealing between the engine block and cylinder head. This rib is not circular because of the combustion chamber shape.