Abstract: A value of ignition delay and a value of a flame spread rate are measured with respect to fuel which is an object to be determined. When the measured value of the ignition delay falls within a range which is smaller than a reference line and constitutes a first range or falls within a range which is larger than a reference line and constitutes the first range, goodness or badness of quality of fuel is determined based on goodness or badness of quality of fuel which is decided in accordance with the first range. When the measured value of ignition delay falls within a range between the reference line and a reference line which constitutes a second range, goodness or badness of quality of fuel is determined based on whether or not a measured value of a flame spread rate falls within a good product range.

Abstract: A value of ignition delay and a value of a flame spread rate are measured with respect to fuel which is an object to be determined. When the measured value of the ignition delay falls within a range which is smaller than a reference line and constitutes a first range or falls within a range which is larger than a reference line and constitutes the first range, goodness or badness of quality of fuel is determined based on goodness or badness of quality of fuel which is decided in accordance with the first range. When the measured value of ignition delay falls within a range between the reference line and a reference line which constitutes a second range, goodness or badness of quality of fuel is determined based on whether or not a measured value of a flame spread rate falls within a good product range.

Abstract: A fuel quality evaluation apparatus and evaluation method enable a reliable evaluation at a low cost. The apparatus includes a combustion chamber which causes an injected fuel to combust, temperature control means which adjusts an interior temperature of the combustion chamber before injection, injection control means which controls the injection, light intensity measurement means which measures flame combustion light intensity, and analysis means which analyzes the measurement result and evaluates a fuel quality. The analysis means causes the fuel to combust a plurality of times, identifies a transformation of a flame light intensity, and evaluates the quality of the fuel based on a variation in the light intensity transformations for each combustion.

Abstract: The spindle motor comprises a shaft, a rotor, and a medium-carrying surface. The rotor is disposed on the outer peripheral side of the shaft, and rotates about the shaft. The medium-carrying surface is disposed on the rotor, and carries a circular-disk-form recording medium. The recording medium is pressed and fastened to the medium-carrying surface by a clamping member. The clamping member is a member that presses the recording medium against a medium-carrying surface. The average value of the widths of the profile peaks in the mean line for the primary profile of the medium-carrying surface in the radial direction is smaller than the average value of the widths of the profile valleys.

Abstract: A cylinder head gasket, interposed between a cylinder head and a cylinder block in an engine, comprises a thin metal plate having a thickness between 0.1 and 2.0 mm, and elastic insulating sheets placed on both surfaces of the thin metal plate and each having a thickness between 0.01 and 0.5 mm, in which: created is a portion at which the thin metal plate is exposed at an inner edge side extending from an inner side of the cylinder block; and also created is an extension portion extending from the cylinder block at an outer edge side extending from an outer side of the cylinder block. Also created is a combustion state detector for detecting a combustion state of an engine, wherein the cylinder head gasket is interposed between the cylinder head and the cylinder block in the engine, the portion at which the thin metal plate is exposed is at the extension portion of the cylinder head gasket, and a signal detecting device is connected thereto.

Abstract: A fuel quality evaluation apparatus and evaluation method enable a reliable evaluation at a low cost. The apparatus includes a combustion chamber which causes an injected fuel to combust, temperature control means which adjusts an interior temperature of the combustion chamber before injection, injection control means which controls the injection, light intensity measurement means which measures flame combustion light intensity, and analysis means which analyzes the measurement result and evaluates a fuel quality. The analysis means causes the fuel to combust a plurality of times, identifies a transformation of a flame light intensity, and evaluates the quality of the fuel based on a variation in the light intensity transformations for each combustion.

Abstract: It is an object of the present invention to make it possible to suppress, to the maximum extent possible, deformation of the recording medium caused by clamping in a spindle motor having a medium-carrying surface. The spindle motor comprises a shaft, a rotor, and a medium-carrying surface. The rotor is disposed on the outer peripheral side of the shaft, and rotates about the shaft. The medium-carrying surface is disposed on the rotor, and carries a circular-disk-form recording medium. The recording medium is pressed and fastened to the medium-carrying surface by a clamping member. The clamping member is a member that presses the recording medium against a medium-carrying surface. The average value Lpave of the widths Lpk of the profile peaks in the mean line for the primary profile of the medium-carrying surface in the radial direction is smaller than the average value Lvave of the widths Lvk of the profile valleys.

Abstract: A cylinder head gasket, interposed between a cylinder head and a cylinder block in an engine, comprises a thin metal plate having a thickness between 0.1 and 2.0 mm, and elastic insulating sheets placed on both surfaces of the thin metal plate and each having a thickness between 0.01 and 0.5 mm, in which: created is a portion at which the thin metal plate is exposed at an inner edge side extending from an inner side of the cylinder block; and also created is an extension portion extending from the cylinder block at an outer edge side extending from an outer side of the cylinder block. Also created is a combustion state detector for detecting a combustion state of an engine, wherein the cylinder head gasket is interposed between the cylinder head and the cylinder block in the engine, the portion at which the thin metal plate is exposed is at the extension portion of the cylinder head gasket, and a signal detecting device is connected thereto.

Abstract: A gasket embedding an ion sensor 5 used for sealing a cylinder head to a cylinder block of an engine which is intervened under pressure between the cylinder head and the cylinder block, the gasket having a detection function of the condition in a combustion chamber. The gasket comprises a metal sheet in which a bore seal is formed at a ring-like bead structure and of an insulation seal layer coating at least the upper surface and the lower surface of the metal sheet so as to include the bead structure. An ionic current detection electrode is formed so as to project into the combustion chamber from the insulation seal layer and further a lug projecting outside from the periphery of the insulation seal layer is served as an ionic current introduction electrode of the sensor.

Abstract: A multifunctional gasket for sealing a gap between two objects by being intervened therebetween, comprising a first base plate and a second base plate including a metal base plate, which is integrally formed thereon. The first base plate comprises a conductive metal base plate layer formed with first and second projecting portions and an opening portion corresponding to a cavity of said two objects, insulation layers integrally formed on both upper and lower surfaces of the conductive metal base plate layer, except for the first and second projecting portions as well as for the opening portion, and microseal coating layers coated on upper and lower surfaces of said insulation layers, whereas the second base plate is provided around the opening portion with an annular bead structure which is formed by being partially bent itself. The gasket is used such that the first projecting portion thrusts toward the opening portion, while the second projecting portion is exposed its outside.

Abstract: A multifunctional gasket intervened between two objects including a space to be sealed comprises a conductive metal base plate layer, an insulation layer integrally laminated at the upper and lower surfaces of the conductive metal base plate layer, and a microseal coating layer coated on the outer surface of the insulation layer. An annular bead structure is formed around an opening corresponding to the space, and when the gasket is intervened between the two objects to be integrated, one end of the conductive metal base plate layer faces the inside of the space and the other end thereof is exposed outside.

Abstract: A cylinder head gasket interposed between a cylinder head and a cylinder block in an engine comprising a metal thin plate having a thickness between 0.1 and 2.0 mm, and elastic insulating sheets placed on both surfaces of the metal thin plate and having a thickness between 0.01 and 0.5 mm, in which a portion at which the metal thin plate is exposed is created on the inner edge side extending from the inner side of the cylinder block, and an extension portion extending from the cylinder block is created on the outer edge side extending from the outer side of the cylinder block. A combustion state detector for detecting a combustion state of an engine, wherein the before described cylinder head gasket is interposed between the cylinder head and the cylinder block in an engine, the portion at which the metal thin plate is exposed is created on the extension portion of the cylinder head gasket, and the signal detecting means is connected thereto.

Abstract: A multifunctional gasket intervened between two objects including a space to be sealed comprises a conductive metal base plate layer, an insulation layer integrally laminated at the upper and lower surfaces of the conductive metal base plate layer, and a microseal coating layer coated on the outer surface of the insulation layer. An annular bead structure is formed around an opening corresponding to the space, and when the gasket is intervened between the two objects to be integrated, one end of the conductive metal base plate layer faces the inside of the space and the other end thereof is exposed outside.

Abstract: A gasket embedding an ion sensor 5 used for sealing a cylinder head to a cylinder block of an engine which is intervened under pressure between the cylinder head and the cylinder block, the gasket having a detection function of the condition in a combustion chamber. The gasket comprises a metal sheet in which a bore seal is formed at a ring-like bead structure and of an insulation seal layer coating at least the upper surface and the lower surface of the metal sheet so as to include the bead structure. An ionic current detection electrode is formed so as to project into the combustion chamber from the insulation seal layer and further a lug projecting outside from the periphery of the insulation seal layer is served as an ionic current introduction electrode of the sensor.

Abstract: A cylinder head gasket interposed between a cylinder head and a cylinder block in an engine comprising a metal thin plate having a thickness between 0.1 and 2.0 mm, and elastic insulating sheets placed on both surfaces of the metal thin plate and having a thickness between 0.01 and 0.5 mm, in which a portion at which the metal thin plate is exposed is created on the inner edge side extending from the inner side of the cylinder block, and an extension portion extending from the cylinder block is created on the outer edge side extending from the outer side of the cylinder block. A combustion state detector for detecting a combustion state of an engine, wherein the before described cylinder head gasket is interposed between the cylinder head and the cylinder block in an engine, the portion at which the metal thin plate is exposed is created on the extension portion of the cylinder head gasket, and the signal detecting means is connected thereto.