Abstract: A rocker arm includes a pair of sidewalls disposed along a heightwise direction so as to be opposed to each other. The sidewalls define a space to house a roller and have opposed portions extending in the heightwise direction relative to adjacent portions which are adjacent to the opposed portions. The opposed portions have thinner portions having smaller thicknesses than the adjacent portions.

Abstract: A rocker arm includes a roller, a support shaft coaxially mounted in the roller and having a first end portion and a second end portion, walls including at least a first wall and a second wall arranged along the rotation axis and opposite each other with having the roller therebetween, the first wall having a first through hole through which the first end portion is inserted and the second wall having a second through hole through which the second end portion is inserted, and plate portions including at least a first plate portion and a second plate portion arranged opposite each other with having the first wall, the second wall and the support shaft therebetween. The first plate portion is in contact with a first end surface of the first end portion and the second plate portion is in contact with a second end surface of the second end portion.

Abstract: A rocker arm includes a roller, a support shaft coaxially mounted in the roller and having a first end portion and a second end portion, walls including at least a first wall and a second wall arranged along the rotation axis and opposite each other with having the roller therebetween, the first wall having a first through hole through which the first end portion is inserted and the second wall having a second through hole through which the second end portion is inserted, and plate portions including at least a first plate portion and a second plate portion arranged opposite each other with having the first wall, the second wall and the support shaft therebetween. The first plate portion is in contact with a first end surface of the first end portion and the second plate portion is in contact with a second end surface of the second end portion.

Abstract: A rocker arm includes a pair of sidewalk disposed along a heightwise direction so as to be opposed to each other. The sidewalk define a space to house a roller and have opposed portions extending in the heightwise direction relative to adjacent portions which are adjacent to the opposed portions. The opposed portions have thinner portions having smaller thicknesses than the adjacent portions.

Abstract: A roller lifter for internal combustion engines is provided, which has higher rigidity of the lifter body, prevents cocking in the cylinder, and can achieve a size reduction. The roller lifter includes a cylindrical lifter body having a sliding surface on an outer circumferential surface thereof and a roller rotatably attached to the lifter body via an axial support pin and making contact with a rotating cam lobe. The lifter body includes a pair of support portions supporting the axial support pin. The axial support pin is mechanically fastened to the pair of support portions, with both ends thereof inserted in support holes formed in the support portions. The lifter body includes an anti-rotation retainer extending radially outward from the sliding surface. The sliding surface is formed on both front and rear sides in the sliding direction of the anti-rotation retainer.

Abstract: A lash adjuster includes a plunger having a bottom wall with a valve hole and a peripheral wall having an oil passage hole and an inner periphery formed with a recessed groove, the plunger defining a high-pressure chamber between the bottom wall and a body, and a partitioning member having an oil passage end located above the oil passage hole. The partitioning member has an oil-passage defining portion located opposite the recessed groove and defining an oil passage between itself and a groove face of the recessed groove. The partitioning member defines 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 causes the reserved hydraulic fluid to flow through the valve hole into the high-pressure chamber. The partitioning member is formed into a cylindrical shape and extends in an up-down direction without any stepped part.

Abstract: A lash adjuster includes a body, a plunger which is inserted into the body and has a bottom wall with a valve hole and a peripheral wall having an oil passage hole and an inner periphery formed with a recessed groove, the plunger defining a high-pressure chamber between the bottom wall and the body, and a partitioning member inserted into the plunger. The partitioning member has an oil passage end located above the oil passage hole. The partitioning member has an oil-passage defining portion located opposite the recessed groove and defining an oil passage between itself and a groove face of the recessed groove. The partitioning member defines a low-pressure chamber inside. The low-pressure chamber reserves a hydraulic fluid flowing through the oil passage hole, the oil passage and the oil passage end. The low-pressure chamber causes the reserved hydraulic fluid to flow through the valve hole into the high-pressure chamber.

Abstract: A roller lifter for internal combustion engines is provided, which has higher rigidity of the lifter body, prevents cocking in the cylinder, and can achieve a size reduction. The roller lifter includes a cylindrical lifter body having a sliding surface on an outer circumferential surface thereof and a roller rotatably attached to the lifter body via an axial support pin and making contact with a rotating cam lobe. The lifter body includes a pair of support portions supporting the axial support pin. The axial support pin is mechanically fastened to the pair of support portions, with both ends thereof inserted in support holes formed in the support portions. The lifter body includes an anti-rotation retainer extending radially outward from the sliding surface. The sliding surface is formed on both front and rear sides in the sliding direction of the anti-rotation retainer.

Abstract: A variable valve mechanism includes a low-speed cam, a high-speed cam, a low-speed rocker arm driven by the low-speed cam, a high-speed rocker arm driven by the high-speed cam, and a switching mechanism. A cam profile of the high-speed cam is set such that it does not exceed a cam profile of the low-speed cam. During low-speed operation, the switching mechanism links the low-speed and the high-speed rocker arms such that the low-speed cam causes the high-speed rocker arm to rock together with the low-speed rocker arm and to open and close a valve. During high-speed operation, the switching mechanism de-links the low-speed rocker arm and the high-speed rocker arm such that the low-speed cam causes the low-speed rocker arm to rock idly and the high-speed cam causes the high-speed rocker arm to rock independently and to open and close the valve. The cam profile of the low-speed cam is set such that the valve closes later than it does with the cam profile of the high-speed cam.

Abstract: A variable valve mechanism includes a low-speed cam, a high-speed cam, a low-speed rocker arm driven by the low-speed cam, a high-speed rocker arm driven by the high-speed cam, and a switching mechanism. A cam profile of the high-speed cam is set such that it does not exceed a cam profile of the low-speed cam. During low-speed operation, the switching mechanism links the low-speed and the high-speed rocker arms such that the low-speed cam causes the high-speed rocker arm to rock together with the low-speed rocker arm and to open and close a valve. During high-speed operation, the switching mechanism de-links the low-speed rocker arm and the high-speed rocker arm such that the low-speed cam causes the low-speed rocker arm to rock idly and the high-speed cam causes the high-speed rocker arm to rock independently and to open and close the valve. The cam profile of the low-speed cam is set such that the valve closes later than it does with the cam profile of the high-speed cam.