Abstract: A cam actuated fuel injector is assembled by engaging an internal thread of a tappet with an external thread of an injector body. The tappet is then rotated with respect to the injector body about a centerline until the internal thread disengages the external thread so that the tappet is then slidable along the centerline. The tappet is biased toward a pre-installation position in which the external thread contacts the internal thread. After installation, the respective internal and external threads guide the sliding movement interaction between the tappet and the injector body when the fuel injector is operational.

Abstract: The mechanical lash adjuster is arranged between a cam and one end of the stem of a valve urged by a valve spring. The lash adjuster comprises an unrotatable housing having a thread, a plunger subjected to the force of the cam and formed with a thread in engagement with the thread of the housing, and a plunger spring urging the plunger against the action of the valve spring. The lead and flank angles of the engaging threads are set such that the engagement threads can slidably rotate under a given shaft load applied to the plunger unless the frictional torque TB, generated by the friction between the slidable frictional surface F2 of the plunger and a shaft load transmission member to act on the plunger, exceeds the thrust torque TF imparted by the shaft load to the plunger.

Abstract: A lash adjuster is provided which includes a cylindrical housing having an open top and formed with an internal thread on an inner periphery thereof, a screw rod having an external thread formed on an outer periphery thereof and in threaded engagement with the internal thread, and a spring biasing the screw rod outwardly of the housing. Each of the internal thread and the external thread having a pressure flank configured to receive pressure when a force that tends to push the screw rod into the housing acts on the screw rod, and a clearance flank having a smaller flank angle than the pressure flank. The screw rod has an end protruding from the housing and configured to support an arm of a valve operating mechanism so as to be pivotable about this end. Oil film expelling grooves are formed in the pressure flank of the external thread, using a tap having a thread that extends so as to cross the internal thread.

Abstract: The object is to prevent rotation of the case when a load is applied to the adjusting screw that tends to push in the adjusting screw.

Abstract: A lash adjuster is provided of which an adjusting screw can be repeatedly fixed in position. The lash adjuster includes a nut member 14 having an internal thread 15 on an inner periphery thereof, an adjusting screw 17 having a external thread 16 on the outer periphery thereof which is in threaded engagement with the internal thread 15, and a return spring 19 biasing the adjusting screw 17 in the direction to protrude from the nut member 14, wherein the lash adjuster further includes an initial setting member 25 detachably disposed between the adjusting screw 17 and the nut member 14, and wherein the adjusting screw 17 is fixed to the nut member 14 due to frictional forces between the initial setting member 25 and the adjusting screw 17 and between the initial setting member 25 and the nut member 14.

Abstract: A lash adjuster is provided of which the adjusting screw can be repeatedly and easily brought into the initial set position. In a lash adjuster including a nut member 14 having an internal thread 20 on the inner periphery thereof, an adjusting screw 15 having an external thread 19 on the outer periphery thereof that is in threaded engagement with the internal thread 20, and a return spring 17 biasing the adjusting screw 15 in the direction to protrude from the nut member 14, a washer 18 is provided which is axially deformed and produces frictional resistance to rotation that serves to prevent rotation of the adjusting screw 15 by its elastic restoring force when the adjusting screw 15 is threaded into the nut member 14.

Abstract: A lash adjuster includes a nut member inserted in a receiving hole formed in the top surface of a cylinder head, an adjusting screw having an external thread on its outer periphery which is in threaded engagement with an internal thread on the inner periphery of the nut member, and a return spring biasing the adjusting screw. The adjusting screw has an end protruding from the nut member and pivotally supporting an arm of a valve gear. The adjusting screw is a solid member. A spring seat is disposed between the adjusting screw and the return spring and kept in point contact with the end of the adjusting screw inserted in the nut member. The spring seat is axially slidably fitted in the inner periphery of the nut member, thereby keeping the adjusting screw and the spring seat coaxial with each other.

Abstract: Provided are a rocker arm, a rocker shaft, a valve cap, an adjust screw, a pivot receiving member, and a valve of an arm type valve operating device that can suppress wear and pitching, and attain a long service life. A multiplicity of minute recesses are provided at random in contact portions with other members of those members. A surface provided with recesses has a surface roughness parameter Ryni that is in a range: 0.4 ?m?Ryni?1.0 ?m, and an Sk value of ?1.6 or less. Accordingly, contact surfaces exhibit a high oil-film-forming capacity, so a long service life is attained even under a condition of low viscosity, thin lubrication and extremely thin oil film.

Abstract: An automatic tappet clearance adjusting device, comprising an adjusting unit adjusting the projected amount of a rocker arm by advancing and retreating an adjust screw to and from the tip of the rocker arm, a pressure setting part electrically controlling the pressure of an air supply source part based on the measurement signals of a primary side pressure sensor measuring the pressure of the air supply source part so that the pressure becomes a specified one, a supply pipeline allowing the air supply source part to communicate with a combustion chamber through a variable orifice, and a control mechanism part controlling the adjusting unit based on measurement signals of a secondary side pressure sensor measuring the pressure of the supply pipeline. The pressure is set to 1.5 kPa by the pressure setting part and the variable orifice.

Abstract: An automatic tappet clearance adjuster comprising a unit for adjusting the projection by advancing/retracting an adjust screw from the forward end of a rocker arm, a section for detecting the torque by rotating the adjust screw, and a control mechanism section for controlling the adjusting unit according to the torque value measured by the torque detecting section. The control mechanism section measures the torque value continuously when a valve is closed by retracting the adjust screw from the open state of the valve. A rotation reference position corresponding to the intersection of a first approximation line and a second approximation line approximating the sections immediately before and after the inflection point of differential value of the torque value is detected as a reference point, and the adjust screw is retracted by a set amount from the reference point.

Abstract: A tappet clearance automatic adjusting device comprising an adjusting unit for advancing/retracting an adjust screw from the forward end of a rocker arm and adjusting the projection amount, a torque detecting section for detecting the torque by rotating the adjust screw, and a control mechanism section for controlling the adjusting unit based on a torque value measured at the torque detecting section. The control mechanism section starts retracting the adjust screw when a valve is opened and continuously measures the torque value obtained when the valve is closed. A position, corresponding to time when variation in the filtering value obtained by smoothing the torque value through moving average is a threshold value or smaller, is detected as a reference point and the adjust screw is retracted from the reference point by a set amount.

Abstract: A tappet clearance automatic adjusting device comprising an adjusting unit for advancing/retracting an adjust screw from the forward end of a rocker arm and adjusting the projection amount, a torque detecting section for detecting the torque by rotating the adjust screw, and a control mechanism section for controlling the adjusting unit based on a torque value measured at the torque detecting section. The control mechanism section starts retracting the adjust screw when a valve is opened and continuously measures the torque value obtained when the valve is closed. A position, corresponding to time when variation in the filtering value obtained by smoothing the torque value through moving average is a threshold value or smaller, is detected as a reference point and the adjust screw is retracted from the reference point by a set amount.

Abstract: A technique which allows an unskilled person to simply adjust a tappet clearance in an engine valve sometimes has a problem in that it can inaccurately adjust clearance because the abutment seat of a magnescale for detecting displacement is not a rocker arm itself and because the abutment position is deviated from the axis of an adjusting screw, due to which readjustment is required. In a method of adjusting and confirming a tappet clearance between an adjusting screw in a rocker arm and a valve stem, the adjusting screw is driven until the face portion of the valve stem is separate from a valve seat, thereafter the adjusting screw is loosened to retract the valve stem while measuring torque, an adjusting origin is determined from the measured torque, and the adjusting screw is loosened by an amount corresponding to a clearance setting specified value from the determined adjusting origin. After that the clearance setting specified value is confirmed with a displacement gauge.

Abstract: A lash adjuster in a valve actuator includes a lifter body having an end plate having its top surface in contact with a cam and formed with a threaded hole in its bottom surface. An adjuster screw is inserted in the threaded hole with its external thread in engagement with the internal thread of the threaded hole. An elastic member is mounted in the threaded hole over the adjuster screw to bias the adjuster screw axially downward. Both of the threads have a sawtooth-shaped section with its pressure flank having a greater flank angle than its clearance flank. One of the pressure flanks is formed with a satin-finished rugged surface which is covered by a hard film which is non-reactive with a low-friction oil. With this arrangement, even after the threads have become worn, the friction coefficient between the thread surfaces is kept substantially constant.

Abstract: For an arm type valve gear in which a lash adjuster is mounted between an arm pivoted by the rotation of a cam and a valve stem, it is a goal to reduce the axial length of the lash adjuster and to suppress wear at the contact portion with the valve stem. An engaging hole is formed in an arm pivoted by the rotation of a cam at a position corresponding to the top end face of a valve stem. A lash adjuster received in the engaging hole includes a nut member, an adjuster screw in threaded engagement with the nut member, an elastic body biasing the adjuster screw toward the valve stem, and a ball joint to reduce the axial length of the lash adjuster. Further, by bringing the bottom end face of the ball joint into surface contact with the top end face of the valve stem, wear at the contact portion is suppressed.

Abstract: A lash adjuster is provided which can maintain stable valve lift. An adjuster screw is mounted into a threaded hole formed in the bottom of the end plate of a lifter body. An elastic member is mounted in the threaded hole to bias the adjuster screw axially downwardly. The female threads of the threaded hole and the male threads of the adjuster screw are serration-shaped. A plurality of axial grooves are formed in the inner periphery of the threaded hole to circumferentially divide the female threads into many separate portions, and satin-finished rough surfaces are formed on the pressure flanks of the male threads by shot-peening to enable quick expulsion of oil film disposed between the opposed pressure flanks, thereby stabilizing the valve lift.

Abstract: A lash adjuster is provided which can keep a constant valve lifting amount. An adjust screw is brought into threaded engagement in a threaded hole formed in the bottom surface of an end plate of a lifter body. The adjust screw is biased in the axial direction by an elastic member. The threads of female threads of the threaded hole and the male threads on the adjust screw are serrated. The surface roughness of the pressure flanks of the serrated threads is set to 0.4 or over to prevent the adjust screw from retracting while turning when push-in loads are applied to the adjust screw from the valve stem, thereby stabilizing the valve lifting amount. Also, a slide member is mounted between the adjust screw and the valve stem and a retaining device is provided to prevent the slide member from turning relative to the nut member while supporting it so as to be movable in the axial direction.

Abstract: The invention relates to a connection (42) between a shaft end (22) of a gas exchange valve (1) of an internal combustion engine and a sleevelike actuating piston (2) of a valve actuator (4), having at least two shell-like key pieces (44, 46), surrounding the shaft end (22) and on whose radially outer circumferential surface there is a conically tapering portion (50), pointing away from a combustion chamber of the engine, which portion extends in complementary fashion to the cone angle of a radially inner conical portion (60) of a conical fastening sleeve that includes the key pieces (44, 46), and the conical fastening sleeve and the key pieces (44, 46) can be braced axially against one another, and protrusions (70) and recesses (72) engaging one another are provided on the radially inner circumferential surface of the key pieces (44, 46) and on the radially outer circumferential surface of the shaft end (22) of the gas exchange valve (1).