Abstract: A lash adjuster includes a body formed into a bottomed cylindrical shape, a plunger movably inserted into the body and having a peripheral wall having an oil passage hole, and a partitioning member inserted into the plunger. The plunger defines a high-pressure chamber between the body and a plunger underside and includes a first threaded portion formed in an inner periphery of the peripheral wall. The partitioning member has an oil passage end located above the oil passage hole and an oil passage is defined between an outer surface of the partitioning member and the plunger peripheral wall. A low-pressure chamber is defined inside the partitioning member to reserve hydraulic fluid flowing through the oil passage hole. The hydraulic fluid is then supplied into the high-pressure chamber. The partitioning member has an outer periphery formed with a second threaded portion threadingly coupled with the first threaded portion.

Abstract: A lash adjuster includes a body, a plunger inserted, into the body and having a bottom wall formed with a valve hole and a peripheral wall standing from the bottom wall and having an oil passage hole, the plunger defining a high-pressure chamber between the bottom wall and the body, a partitioning member inserted into the plunger and having an oil passage end located above the oil passage hole, the partitioning member defining an oil passage between itself and the plunger peripheral wall, the partitioning member having a low-pressure chamber reserving a hydraulic fluid flowing through the oil passage hole, the oil passage and the oil passage end, the low-pressure chamber causing the reserved hydraulic fluid to flow through the valve hole into the high-pressure chamber, and a spacer interposed between the plunger peripheral wall and the partitioning member so that the partitioning member is held in the plunger.

Abstract: The present invention provides a variable valve mechanism of an internal combustion engine, which includes a main arm having at a rear end thereof a supported portion that is continuously supported swingably by a support member without floating upward, a sub arm which has a tip end to which a roller contacting a cam is rotatably attached, in which a center of the roller is located rearward of the pressing portion and forward of a swing center of the supported portion, which has a rear end that is swingably supported with respect to the main arm by a support pin, and in which a center of the support pin is located rearward of the center of the roller and forward of the swing center of the supported portion, and a switch pin that is inserted in a central portion of the roller.

Abstract: The present invention provides a variable valve mechanism of an internal combustion engine which includes a rotary cam, an output arm, an input member, and a switching device that switches between a coupled state and a non-coupled state. The variable valve mechanism changes a drive state of the valve by the switching operation. The input member includes an annular input roller that contacts the rotary cam, and a swing pin that is inserted into the input roller so as to rotatably support the input roller and that swings relative to the output arm when in the non-coupled state. A center of the relative swinging movement is located at a position different from a rotation center of the input roller which is located inward of the input roller.

Abstract: A lubrication structure for a rocker arm includes a lash adjuster mounted in an accommodating portion located in an end of the rocker arm and a pushrod abutting against a lower end of the lash adjuster. The rocker arm is formed with an arm-inside oil supply passage for supplying lubrication oil to the lash adjuster. The lubrication oil guided into the accommodating portion is further guided through a through guide hole of the accommodating portion to an outer peripheral surface of the accommodating portion. The lubrication oil is further guided from an outer oil supply passage formed downwardly in the outer surface of the accommodating portion to the abutment between the lash adjuster and the pushrod.

Abstract: A variable valve mechanism that is downsized by providing a crank mechanism in place of an egg-shaped cam on an input shaft that is rotationally driven by a crankshaft of an internal combustion engine. A variable valve mechanism (30) having a variable mechanism (30) that changes the opening/closing amount of a valve (13), includes an input shaft (12) that is rotationally driven by an internal combustion engine. The input shaft (12) is provided with a crank mechanism (14) that is connected to the variable mechanism (30) and converts the rotational motion of the input shaft (12) into reciprocating motion for opening and closing the valve (13).

Abstract: A method manufactures a fuel delivery pipe including a crude metal made of forged iron, a nickel-phosphorus plating layer formed on an inner surface of the crude metal, and a nonmetal paint film formed on an outer surface of the crude metal. The method includes coating the outer surface of the crude metal with paint to form the paint film, machining the crude metal with the paint film formed thereon to form a machined surface inside the crude metal, and electroless plating the machined crude metal in nickel-phosphorus plating solution to form the nickel-phosphorus plating layer on the machined surface.

Abstract: The present invention provides a rocker arm with a lash adjuster which includes a rocker arm body portion including a circular fitting hole, a large-diameter hole, and a step portion at a boundary between the fitting hole and the large-diameter hole; a lash adjuster having a snap ring groove formed on an outer circumferential surface of the lash adjuster, and a snap ring fitted to the snap ring groove, wherein the lash adjuster is inserted in the fitting hole, the snap ring increases in diameter, hooks on the step portion, and prevents the lash adjuster from slipping off; and a diameter-reducing member that is assembled in the rocker arm body portion and that reduces the diameter of the snap ring by operation of the diameter-reducing member from an outside of the rocker arm body portion until the snap ring is not engaged with the step portion.

Abstract: The present invention provides a shim for a valve drive mechanism which is interposed between a pad surface of a rocker arm and a stem end surface of a valve. The shim includes a ship top surface that is contacted by the pad surface. The shim top surface is rotated about a center thereof to be cut, is provided with a center hole at the center thereof, and is shaped such that the pad surface does not contact an intersection line between an inner peripheral surface of the center hole and the shim top surface when the rocker arm is swung.

Abstract: A vehicle engine includes: a cylinder head; a cam housing fixed to a top of the cylinder head; a cam cap fixed to a top of the cam housing; a camshaft rotatably supported between the cam housing and the cam cap, the camshaft supporting a cam; a rocker arm configured to be pushed by the cam; and a valve configured to operate by being pushed by the rocker arm; and an oil pipe that is formed integrally with the cam cap. Lubricant oil is supplied through the oil pipe to a contact point between the cam and the rocker arm.

Abstract: A vehicle engine includes a cylinder head, a cam housing fixed to a top of the cylinder head, a cam cap fixed to a top of the cam housing, a camshaft rotatably supported between the cam housing and the cam cap, the camshaft supporting a cam, a rocker arm configured to be pushed by the cam, and a valve configured to operate by being pushed by the rocker arm. The vehicle engine has an oil pipe that is formed integrally with the cam housing.

Abstract: A vehicle engine includes: a cylinder head; a cam housing fixed to a top of the cylinder head; a cam cap fixed to a top of the cam housing; a camshaft that is rotatably supported between the cam housing and the cam cap; a cam provided around the camshaft; a rocker arm that is pushed by the cam; a supporting member that supports one end of the rocker arm from below; a cylindrical bore portion for mounting the supporting member; and a base portion for supporting a bottom surface of the supporting member. The bore portion is provided integrally with the cam housing. The base portion is provided integrally with the cylinder head.

Abstract: A rocker arm includes a roller rotatably mounted between two sidewalls thereof. The roller is pressed by a cam. The rocker arm also includes two washers that reduce a wobbling motion of the roller with respect to the cam. The washers guiding mechanism the rocking movement of the rocker arm in the up-and-down direction, thereby reducing wobbling motion of the rocker arm when an engine runs.

Abstract: A fuel delivery pipe delivers fuel to a plurality of fuel injection valves corresponding to cylinders of an internal-combustion engine. The fuel delivery pipe includes a pipe body made of carbon steel for machine structural use and a plating film disposed on an inner surface of the pipe body. Preferably, the fuel delivery pipe includes a plating film disposed on an outer surface of the pipe body.

Abstract: A cam housing 3 in accordance with the present invention includes: a body portion 4 that is provided separately from a cylinder head 1, supports a camshaft 2 for driving a valve 10 provided in the cylinder head 1, and is fixed to the cylinder head 1; a sub housing 20 that includes a mounting concavity 21 for mounting a lash adjuster 18 and is fixed to the body portion 4 with a mounting face 20A thereof forced against an outer face of the body portion 4, the mounting face 20A being different from the face wherein an opening of the mounting concavity 21 is provided; and an air vent 22 that penetrates the sub housing 20 between a wall surface thereof and the mounting face 20A thereof and thereby is provided in the sub housing 20, the wall configuring an inner space formed in the mounting concavity wherein the lash adjuster 18 is mounted.

Abstract: A rocker arm configured to be supported by a support portion of an internal-combustion engine and to be driven in a swinging manner by a cam. The rocker arm includes a rocker arm body including a cam follower having a first slide-contact surface, wherein the first slide-contact surface is in sliding contact with the cam, a fulcrum portion including a second slide-contact surface, wherein the second slide-contact surface swingably is in sliding contact with respect to the support portion, and a lubricant discharging portion for biasing a lubricant supplied from the fulcrum portion in a direction toward the first slide-contact surface and discharging the lubricant. The fulcrum portion penetrates the rocker arm and is fastened to the rocker arm body. The fulcrum portion has a through hole supplying the lubricant to the lubricant discharging portion through the rocker arm body.

Abstract: A hydraulic auto-tensioner includes a high-pressure oil chamber and a low-pressure oil chamber, and oil (L) in the high-pressure oil chamber passes through a clearance (G) between a cylinder (17) and a piston portion (18) of a plunger and leaks into the low-pressure oil chamber from an end of the clearance (G) near an end surface of the cylinder (17). A recessed groove (40) is provided in an inner peripheral surface of the cylinder (17) by a conical surface (41) having a groove angle of 5 to 15 degrees from the end of the clearance (G), a throttle portion (45) projecting onto the piston portion (18) side is provided further toward the end surface side of the cylinder than the groove (40) in the inner peripheral surface of the cylinder (17), and a throttle gap (A) larger than the clearance (G) is formed between the throttle portion (45) and the piston portion (18).

Abstract: A rocker arm supported by a support portion of an engine and to be driven by a cam includes a sheet-metal rocker arm body manufactured by plastic working and including a cam follower, a fulcrum portion manufactured by cutting and including a through hole supplying lubricant, and a lubricant discharging hole. The cam follower includes a first slide-contact surface being in sliding contact with the cam. The lubricant discharging hole is defined by an outer surface of the fulcrum portion and an outer surface of the sheet-metal rocker arm body and in communication with the through hole. The lubricant discharging hole biases the lubricant supplied from the through hole in a direction toward the first slide-contact surface.

Abstract: A return spring is formed using a compression coil spring that is installed so that its axial direction is an up-down direction. The return spring is provided in a high-pressure chamber, and powers a plunger in an upwards direction. A coil diameter of the return spring varies along the axial direction. When the return spring is in a maximally compressed state, an axial direction dimension (up-down direction dimension) is smaller than a dimension that is a thickness of a spring wire multiplied by the number of coil turns. Hence, an overall height of a lash adjuster A can be reduced in comparison to when a return spring with a constant coil diameter over an entire length is used.

Abstract: The present invention provides a variable valve mechanism which includes a camshaft having a drive cam, a rocker shaft provided parallel to the camshaft, and a variable mechanism that is provided on the rocker shaft and interposed between the drive cam and a valve, and that changes an opening/closing amount of the valve. The variable mechanism includes a main arm that engages with the drive cam, a cam arm that has a cam surface pressing the valve, a control cam that is provided on the rocker shaft, and has an outer peripheral surface whose distance from a shaft center of the rocker shaft varies gradually, and a displacement member whose distance from the shaft center is changed by turning of the control cam. A relative phase between the main arm and the cam arm is displaced as the distance between the displacement member and the shaft center changes.