Abstract: The present invention provides a variable valve mechanism that varies amounts of opening and closing of a valve includes a rotating cam, a rocker arm, two lash adjusters, a hydraulic passage, and a switching mechanism. The rocker arm includes an input member and an output member. The two lash adjusters support the rocker arm so that the rocker arm can rock. The hydraulic passage includes an internal oil passage that is provided in an interior of at least one of the lash adjusters, and an arm oil passage that is provided in an interior of the rocker arm and that is connected from the internal oil passage. The switching mechanism uses a hydraulic pressure in the hydraulic passage to perform a switching between a linked state and a released state, and the switching varies the amounts of the opening and the closing of the valve.

Abstract: A rocker arm that is rockably attached to a cylinder head actuates a valve by a guide groove that is formed at an end thereof engaging with an upper end of a valve stem, and a roller that is mounted in a roller housing portion of the arm main unit contacting against a cam and rocking. The guide groove is formed by press working ends of the arm main unit in the thickness direction of the plate material to form a pair of walls, and thereafter applying sandwiching pressure in the lateral direction to the walls to increase the height thereof.

Abstract: The present invention provides a variable valve operating mechanism which includes two valve operating members for opening and closing two valves individually, a drive cam provided on a single camshaft, two swing arms for transmitting a power of the drive cam to the valve operating members individually by swinging about a different axis to the camshaft, and a variable device for modifying a displacement of the swing arm per rotation of the drive cam in accordance with an operating condition of an internal combustion engine. The variable device includes a single control shaft, an actuator for driving the control shaft, and a cam device that operates in conjunction with the control shaft to dissimilate the displacement of the two swing arms.

Abstract: The present invention provides a variable valve mechanism which includes a rotating cam provided on a camshaft, a swing arm that contacts with the rotating cam to swing, a drive arm that drives a valve in conjunction with the swing arm, a variable arm that turns the drive arm around a swing axis of the swing arm, an actuator that drives the variable arm, and cam device that is provided between the swing arm and the drive arm. The variable arm is provided so as to be able to rotate relatively around the same axis as the swing arm, and the cam device changes the initial position of the drive arm with respect to the swing arm accompanying the turning of the drive arm.

Abstract: The present invention provides a variable valve mechanism that varies amounts of opening and closing of a valve includes a rotating cam, a rocker arm, two lash adjusters, a hydraulic passage, and a switching mechanism. The rocker arm includes an input member and an output member. The two lash adjusters support the rocker arm so that the rocker arm can rock. The hydraulic passage includes an internal oil passage that is provided in an interior of at least one of the lash adjusters, and an arm oil passage that is provided in an interior of the rocker arm and that is connected from the internal oil passage. The switching mechanism uses a hydraulic pressure in the hydraulic passage to perform a switching between a linked state and a released state, and the switching varies the amounts of the opening and the closing of the valve.

Abstract: A lash adjuster includes a plunger and a cylinder. The cylinder includes a high-pressure chamber defined therein. The plunger has a valve port provided through a bottom wall thereof. The valve port includes a seat. A spherical valve body is accommodated in the high-pressure chamber. The valve body is made of ceramic material containing silicon nitride. The valve body is arranged to have a surface roughness average (Ra) of equal to or less than 0.13 ?m. The valve body is arranged to have a contact pressure of equal to or lower than 1386 Mpa with the seat in a state where the valve port is closed by the valve body.

Abstract: The present invention provides a variable valve mechanism which includes a rotating cam provided on a camshaft, a swing arm that contacts with the rotating cam to swing, a drive arm that drives a valve in conjunction with the swing arm, a variable arm that turns the drive arm around a swing axis of the swing arm, an actuator that drives the variable arm, and cam device that is provided between the swing arm and the drive arm. The variable arm is provided so as to be able to rotate relatively around the same axis as the swing arm, and the cam device changes the initial position of the drive arm with respect to the swing arm accompanying the turning of the drive arm.

Abstract: A rocker arm 6 that is rockably attached to a cylinder head 1 actuates a valve 4 by means of a guide groove 73b that is formed at an end thereof engaging with an upper end of a valve stem 41, and a roller 8 that is mounted in a roller housing portion 72 of the arm main unit 7 contacting against a cam 31 and rocking. The guide groove 73b is formed by press working ends of the arm main unit 7 in the thickness direction of the plate material to form a pair of walls 73d, and thereafter applying sandwiching pressure in the lateral direction to the walls 73d to increase the height thereof.

Abstract: The present invention provides a variable valve operating mechanism which includes two valve operating members for opening and closing two valves individually, a drive cam provided on a single camshaft, two swing arms for transmitting a power of the drive cam to the valve operating members individually by swinging about a different axis to the camshaft, and a variable device for modifying a displacement of the swing arm per rotation of the drive cam in accordance with an operating condition of an internal combustion engine. The variable device includes a single control shaft, an actuator for driving the control shaft, and a cam device that operates in conjunction with the control shaft to dissimilate the displacement of the two swing arms.

Abstract: A hydraulic valve lifter is held in the recess of the rocker arm swingably pivoted to the rocker shaft. An oil pressure chamber is formed between the lifter body and the plunger. An oil chamber to supply the oil to the oil pressure chamber is formed between the plunger and the recess. An oil supply path to supply the oil through the oil path of the rocker shaft communicates to the oil chamber. A return path is provided extending from the top of the oil chamber to a clearance between the inside of the rocker arm hole and the outside of the rocker shaft or to a clearance between the outside of the lifter body and the inside of the rocker arm recess. With this arrangement of the device, the air infiltrating the oil chamber can be discharged from the top of the oil chamber via the return path and the clearance, thereby preventing invasion of the air into the oil pressure chamber and ensuring normal functioning of the hydraulic valve lifter.