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 lifter rotation preventing structure includes a lifter body, a retainer and a biasing member. The lifter body is inserted into a sliding hole of a housing and reciprocated according to rotation of a cam. The lifter body has a peripheral wall slidable in a sliding hole and a partition wall partitioning an inside of the peripheral wall into a first space where the cam is located and a second space located opposite the first space. The retainer has a retainer body connected to an engaging member and a rotation preventing protrusion protruding from an outer periphery of the retainer body and fittingly extending through the peripheral wall. The rotation preventing protrusion has a distal end moved into a rotation preventing groove to prevent the lifter body from rotation. The biasing member interposed between the retainer body and the housing to bias the lifter body to the cam side.

Abstract: A lifter structure includes a cylindrical member configured to be reciprocally slid in a guide hole of a lifter guide according to rotation of a cam and having an engagement groove and a rotation-preventing member which is separate from the cylindrical member and is disposed so as to face an interior of the guide hole. The rotation-preventing member is inserted into the engagement groove to abut against a groove edge of the engagement groove in a rotation direction of the cylindrical member, thereby preventing the cylindrical member from rotation in the guide hole.

Abstract: A lifter includes a roller caused to abut against a cam thereby to be pressed and a lifter body rotatably supporting the roller and housed in a guide hole of a lifter guide so as to be reciprocable in the guide hole. The lifter body includes a cylindrical part and a rotation stopper. The cylindrical part has an outer periphery formed into a cylindrical shape such that the outer periphery is slidable on an inner periphery of the guide hole. The cylindrical part has one of two axial ends, the one end being formed with a skirt covering the roller. The rotation stopper is formed to protrude outward from the other axial end of the cylindrical part, the other axial end being located opposite a side where the skirt is located. The rotation stopper prevents the lifter body from being rotated about an axis thereof relative to the lifter guide.

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 lifter includes a roller caused to abut against a cam thereby to be pressed and a lifter body rotatably supporting the roller and housed in a guide hole of a lifter guide so as to be reciprocable in the guide hole. The lifter body includes a cylindrical part and a rotation stopper. The cylindrical part has an outer periphery formed into a cylindrical shape such that the outer periphery is slidable on an inner periphery of the guide hole. The cylindrical part has one of two axial ends, the one end being formed with a skirt covering the roller. The rotation stopper is formed to protrude outward from the other axial end of the cylindrical part, the other axial end being located opposite a side where the skirt is located. The rotation stopper prevents the lifter body from being rotated about an axis thereof relative to the lifter guide.

Abstract: A lifter rotation preventing structure includes a lifter body, a retainer and a biasing member. The lifter body is inserted into a sliding hole of a housing and reciprocated according to rotation of a cam. The lifter body has a peripheral wall slidable in a sliding hole and a partition wall partitioning an inside of the peripheral wall into a first space where the cam is located and a second space located opposite the first space. The retainer has a retainer body connected to an engaging member and a rotation preventing protrusion protruding from an outer periphery of the retainer body and fittingly extending through the peripheral wall. The rotation preventing protrusion has a distal end moved into a rotation preventing groove to prevent the lifter body from rotation. The biasing member interposed between the retainer body and the housing to bias the lifter body to the cam side.

Abstract: A lifter structure includes a cylindrical member configured to be reciprocally slid in a guide hole of a lifter guide according to rotation of a cam and having an engagement groove and a rotation-preventing member which is separate from the cylindrical member and is disposed so as to face an interior of the guide hole. The rotation-preventing member is inserted into the engagement groove to abut against a groove edge of the engagement groove in a rotation direction of the cylindrical member, thereby preventing the cylindrical member from rotation in the guide hole.

Abstract: A lash adjuster includes a body, a plunger inserted into the body and having a bottom wall with a valve hole and a peripheral wall having an oil passage hole, and a partitioning member. The partitioning member is inserted into the plunger and has an oil passage end located above the oil passage hole in an inserted state. The partitioning member has a recess defining an oil passage together with the peripheral wall. The partitioning member defines a low-pressure chamber reserving hydraulic fluid and has, together with the recess, a press-fit portion abutting against an inner periphery of the peripheral wall when the partitioning member is inserted into the plunger. Consequently, the partitioning member has a deformed cross-sectional shape except for a circular shape when cut at a same height as the oil passage hole. The partitioning member has a same cross-sectional shape over its entire height.

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: A lash adjuster includes a body, a plunger inserted into the body and having a bottom wall with a valve hole and a peripheral wall having an oil passage hole, and a partitioning member. The plunger defines a high-pressure chamber. The partitioning member is inserted into the plunger and has an oil passage end located above the oil passage hole in an inserted state. The partitioning member has a recess defining an oil passage together with the peripheral wall. The partitioning member defines a low-pressure chamber reserving hydraulic fluid and has, together with the recess, a press-fit portion abutting against an inner periphery of the peripheral wall when the partitioning member is inserted into the plunger. Consequently, the press-fit portion has a deformed cross-sectional shape except for a circular shape when cut at a same height as the oil passage hole.

Abstract: A lash adjuster includes a body, a plunger inserted, into the body and having a bottom wall formed with a valve h ole 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: A rocker arm unit which constitutes a valve gear of an internal combustion engine, includes a lash adjuster including a cylindrical body and a plunger formed into a cylindrical shape and accommodated in the body, a rocker arm extending in a direction perpendicular to a vertical direction, and a clip configured to be fixed to an upper end of the body and formed with a retainer having a retaining portion which is configured to be swaged onto an inner circumferential surface of the upper end of the body. The clip has an extension extending integrally from the retainer. The extension has an upper end engaged with the rocker arm to prevent the rocker arm from falling off the lash adjuster. The retaining portion is configured to abut against the stepped portion of the plunger from above to prevent the plunger from coming off upwardly out of the body.

Abstract: A lash adjuster includes a cylindrical body, a cylindrical plunger, a low pressure chamber defined in the plunger, a high pressure chamber defined in a hollow lower interior of the body and filled with an operating fluid, a check valve allowing the operating fluid to flow into the high pressure chamber when in a valve-opened state and cutting off flow of the operating fluid from the high pressure chamber into the low pressure chamber when in a valve-closed state. A retainer of the check valve includes a base plate and a cylindrical portion extending upward from an outer circumferential edge of the base plate so as to surround the valve element. The base plate includes a central portion on which the valve element is placed and which has an upper surface formed with a swollen portion. The cylindrical portion has a plurality of openings formed through it circumferentially equiangularly.

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: A rocker arm unit comprises a lash adjuster having a plunger extending axially and a cylindrical body which houses the plunger so that the plunger is slidable; a rocker arm supported by an upper end of the plunger and swung with the supported position serving as a pivot; and a clip which is fixed to the body so as to extend from the fixed position to engage the rocker arm, thereby restricting drop of the rocker arm out of the lash adjuster.

Abstract: A lash adjuster in which, when a plunger descends, a valve element moves to a valve-closed position without delay. A check valve (27) has a valve hole (28) penetrating through a bottom wall (17) of a plunger (12), a retainer (30) placed in a high pressure chamber (25) and vertically moving together with the plunger (12), and a valve element (29) capable of vertically moving in the high pressure chamber (25), between a valve-opened position at which the valve element (29) is separated from the valve hole (28) to be placed on the retainer (30) and a valve-closed position which is located above the valve-opened position and at which the valve element (29) closes the valve hole (28). When the plunger (12) is at a standstill, the valve element (29) is held at the valve-opened position by the self-weight.

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.