Abstract: To provide an alumina-based fibrous mass having a high areal pressure and is usable as a holding material for an exhaust gas cleaners and a production process thereof; the alumina-based fibrous mass has a chemical composition containing an Al2O3 in an amount of 70% or more and less than 90% and having a total pore volume of 0.0055 mL/g or less.

Abstract: There is provided an alumina fiber capable of fixing a honeycomb carrier while maintaining elasticity for a long period of time even in a severe usage environment, and an alumina fiber aggregate formed of the fiber. Problems in a gripping material of an automotive honeycomb carrier are solved by applying an alumina fiber containing from 70 to 98% by mass of alumina and from 2 to 30% by mass of silica, having an average fiber diameter of from 3.0 to 8.0 ?m, a ratio of fibers having a fiber diameter exceeding 10 ?m being 5% or less in terms of the number of fibers and a size of a mullite crystallite contained in each fiber of from 10 to 1500 ?, and by forming an alumina fiber aggregate by using the fibers.

Abstract: To provide an alumina-based fibrous mass having a high areal pressure and is usable as a holding material for an exhaust gas cleaners and a production process thereof; the alumina-based fibrous mass has a chemical composition containing an Al2O3 in an amount of 70% or more and less than 90% and having a total pore volume of 0.0055 mL/g or less.

Abstract: A saddle ride type four-wheel vehicle includes an electronic control type fuel injection system in a fuel supply system for an engine mounted thereon, wherein a fuel pump is disposed on the rear side relative to the rotational center axis of front wheels and on the front side relative to the engine.

Abstract: To provide an inner shim that is unlikely to fall off from a spring retainer even when an anomalous operation of a valve occurs. A spring retainer fixed to the upper end portion of a valve shaft has a shim-attachment hole. An inner shim is fitted into the shim-attachment hole. The bottom face of the inner shim is in contact with the upper end portion of the valve shaft, and the top face of the inner shim is positioned below the upper edge of the shim-attachment hole. A tappet is disposed above the spring retainer, and is allowed to move freely in the axial direction of the valve shaft. A shim-holding projection sticks out from the under face of the tappet, and extends downward. The projection enters, from above, the inside of the shim-attachment hole, and is in contact with the top face of the inner shim.

Abstract: To provide an inner shim that is unlikely to fall off from a spring retainer even when an anomalous operation of a valve occurs. A spring retainer fixed to the upper end portion of a valve shaft has a shim-attachment hole. An inner shim is fitted into the shim-attachment hole. The bottom face of the inner shim is in contact with the upper end portion of the valve shaft, and the top face of the inner shim is positioned below the upper edge of the shim-attachment hole. A tappet is disposed above the spring retainer, and is allowed to move freely in the axial direction of the valve shaft. A shim-holding projection sticks out from the under face of the tappet, and extends downward. The projection enters, from above, the inside of the shim-attachment hole, and is in contact with the top face of the inner shim.

Abstract: The invention relates to an engine arrangement that increases the degree of freedom of the engine state sensor while decreasing the size of the engine body. More specifically, the engine is formed with a chamber for housing a valve train and serving dually as a return oil path of the lubricating oil after having lubricated the valve train. The engine includes an oil temperature sensor partially exposed on one side of a cylinder block and an exhaust pipe partially exposed on the opposite side of the cylinder block.

Abstract: A saddle ride type four-wheel vehicle includes an electronic control type fuel injection system in a fuel supply system for an engine mounted thereon, wherein a fuel pump is disposed on the rear side relative to the rotational center axis of front wheels and on the front side relative to the engine.

Abstract: A saddle riding type four-wheeled vehicle, suitable for rough terrain running, includes an engine having an electronically controlled fuel injection system. The vehicle also includes a throttle body disposed in back of a cylinder head of the engine. This configuration substantially protects the engine from drawing in mud, dust, and the like, and also eliminates the need for a protector of a throttle body. The fuel pump unit of the fuel injection system integrates the fuel pump, the fuel filter, and the pressure regulator into a single housing, to simplify the fuel piping required to connect different parts of the fuel supply system, as compared with conventional structures. This facilitates procedures of removing and installing the fuel tank and the fuel pump unit. The feature also reduces pumping loss of the fuel pump as well as parts cost.

Abstract: The invention relates to an engine arrangement that increases the degree of freedom of the engine state sensor while decreasing the size of the engine body. More specifically, the engine is formed with a chamber for housing a valve train and serving dually as a return oil path of the lubricating oil after having lubricated the valve train. The engine includes an oil temperature sensor partially exposed on one side of a cylinder block and an exhaust pipe partially exposed on the opposite side of the cylinder block.

Abstract: A relief valve having a cylindrical case with one side thereof communicated with a fluid-pressure source, a relief piston accommodated in the cylindrical case and slidable therein, a return spring for pressing the relief piston against the fluid-pressure source, a damper chamber provided on a rear-surface side of the relief piston, said damper chamber communicated with the fluid-pressure source through an orifice of the relief piston and used for displaying a buffer action against an operation of the relief piston, and a relief hole bored through a wall of the cylindrical case, the relief hole communicated with the fluid-pressure source when the relief piston retreats due to an increase in pressure generated by the fluid-pressure source.

Abstract: A crankshaft holding structure 10 for use in an internal combustion engine has a front crankshaft 35 supported by a radial roller bearing 25 that is fixed to a crankcase 11 and has an inner side surface 26a. A land 40 of the front crankshaft 35 is held in abutment against the inner side surface 26a to limit crankshafts 30, 35 against axial elongation and deformation. The radial roller bearing 25 has an outside diameter D1 that is the same as an outside diameter of a radial ball bearing 20. The forgoing arrangement includes simplified bushings cast in a crankcase and having bearing press-fitted therein, that allows the bushings to be used as common parts.

Abstract: An oil tank of large capacity is integrally mounted directly to a front side of a front case cover in a power unit including a hydrostatic type continuously variable transmission. The power unit is driven by a crankshaft within a crankcase, and a lower portion of the oil tank is connected through an inlet and an outlet both formed in the front case cover to an oil pump disposed inside the front case cover in order to dispense with piping and fittings required when a tank is located separately from a power unit.

Abstract: A crankshaft holding structure 10 for use in an internal combustion engine has a front crankshaft 35 supported by a radial roller bearing 25 that is fixed to a crankcase 11 and has an inner side surface 26a. A land 40 of the front crankshaft 35 is held in abutment against the inner side surface 26a to limit crankshafts 30, 35 against axial elongation and deformation. The radial roller bearing 25 has an outside diameter D1 that is the same as an outside diameter of a radial ball bearing 20. The foregoing arrangement includes simplified bushings cast in a crankcase and having bearings press-fitted therein, that allows the bushings to be used as common parts.

Abstract: An overhead valve type internal combustion engine having a breather chamber without increasing the size of the internal combustion engine by taking advantage of a space that is already formed. An overhead valve type internal combustion engine includes a cylinder bore formed in a cylinder, a freely rotatable cam shaft located in a cylinder head, and also located to the side of the cylinder bore viewed from a direction of a centerline of the cylinder, a chain chamber, located to the side of the cylinder bore, for housing a chain for rotationally driving the cam shaft, and a breather chamber located so as to be below the cam shaft and parallel to the cylinder bore on one side of the chain chamber.

Abstract: In an engine having a dry sump type lubrication structure, a feed pump, a sub-scavenging pump, and a main scavenging pump of an oil pump are all integrally provided by disposing a feed pump rotor, a sub-scavenging pump rotor, and a main scavenging pump rotor in parallel on the same common drive shaft. This arrangement reduces the necessary size and weight of a feed pump and a scavenging pump while increasing the pumping capacity thereof The oil sump is divided into a plurality of oil sumps which are different from each other in their longitudinal and lateral positions. Oil in a first oil sump and a second oil sump is pumped by the main scavenging pump and sub-scavenging pump, respectively. A housing of the oil pump is composed of a first block, a second block, a third block, and a fourth block, wherein oil passages are provided in these blocks.