Toyota Jidosha Kabushiki Kaisha

Toyota Jidosha Kogyo Kabushiki Kaisha

Denson Corporation

Tadao Hasegawa

Kiyoshi Sugimoto

Yoshihito Moriya

Noriyuki Iden

Noboru Takagi

Osamu Sato

Takayoshi Nakagawa

Shinitiro Kikuoka

A valve characteristic controller for an engine including variable valve actuation mechanisms, one for a first valve and another for a second valve, to vary the opening and closing timings of the valves. The controller executes main control to calculate a target timing of the first valve in accordance with an operation state of the engine and has the corresponding variable valve actuation mechanism adjust the timing of the first valve to the target timing. Further, the controller executes sub-control to calculate a target timing of the second valve based on a target valve overlap amount and the actual timing of the first valve and has the corresponding variable valve actuation mechanism adjust the valve timing of the second valve to the target timing. The main control is executed on the one of the two variable valve actuation mechanisms having a lower response speed.

Valve characteristic controller and control method for internal combustion engine

A valve timing changing apparatus for changing valve timings of intake and exhaust valves inhibits a deterioration in the precision of a change of a valve overlap period. A first variable valve timing mechanism (first VVT) is mounted to an intake cam shaft, and a second variable valve timing mechanism (second VVT) is mounted to a crank shaft. A timing belt drivingly couples a cam pulley mounted to an exhaust cam shaft, a cam pulley of the first VVT, and a cam pulley of the second VVT to one another. The first VVT changes a rotational phase of the intake cam shaft so as to change a valve timing of intake valves. The second VVT changes rotational phases of both the intake and exhaust cam shafts so as to simultaneously change valve timings of the intake and exhaust valves.

Valve timing changing apparatus for internal combustion engine

An apparatus for adjusting an engine valve. The valve is actuated by a cam on a camshaft. The cam has a cam surface that drives the valve by way of a follower. The radius of the cam surface varies in the axial direction in an angular section of the cam. A pulley surrounds one end of the camshaft. The camshaft is rotated relative to the pulley to change the valve timing and the camshaft is also moved axially to change the lift of the valve by changing the area of the cam surface engaged by the follower.

Variable valve performance mechanism in internal combustion engine

A valve driving apparatus for an internal combustion engine. Each combustion chamber has a pair of intake ports and a pair of intake valves for selectively opening and closing the intake ports. Each intake valve is driven with a variable amount of valve lift. The apparatus includes a camshaft rotatably supported by the engine, cams, cam followers, a shaft moving mechanism, and brackets. Each cam lifts an associated intake valve in response to rotation of the camshaft. Each cam has a cam nose for lifting a corresponding intake valve. The radius of the cam nose varies in the axial direction. Cam followers transmit movement of the intake cams to the intake valves. The shaft moving mechanism moves the cams relative to the valves in an axial direction of the camshaft thereby varying the amount of valve lift. A lifter structure is provided that is circularly shaped to improve manufacturing accuracy. In another embodiment, the valves are oriented to increase the amount of axial movement that the cam can make, which results in greater optimization of the air intake amount.

Valve driving apparatus for engine

Each of a positive spline member and a negative spline member is engaged through a spline engagement with a vane rotor. Both the positive spline member and the negative spline member are securely fixed to a cam shaft by means of a bolt. The cam shaft causes an axial reciprocative movement relative to the vane rotor. Each external spline formed on the positive spline member is brought into contact at its trailing side with an internal spline of the vane rotor. Each external spline formed on the negative spline member is brought into contact at its leading side with an internal spline of the vane rotor. This arrangement eliminates any backlash formed between the internal splines of the vane rotor and the external splines of the positive and negative spline members.

Valve timing control apparatus for an internal combustion engine

A valve lifter structure having a follower which tilts in a guide groove, for a mechanism for varying valve characteristics of a poppet valve by axial displacement of a three-dimensional cam having a profile varying in the axial direction, which is easily machined without degrading a mechanical strength. A guide groove is formed on a top surface of a valve lifter interposed between a cam and a top of a valve stem of a poppet valve to extend perpendicular to the axis of the cam. A follower is located in the guide groove, which extends in parallel to the guide groove and is capable of tilting in accordance with the change of the cam profile while being brought into slide-contact with the guide groove, and is inhibited from displacing in the extending direction by a limiting means. The guide groove is formed to have opposite open ends. The limiting means is defined by a stopper located on the guide groove side and an abutment member located on the follower side to abut to the stopper. The abutment member is defined by a pair of walls of the follower spaced at a distance opposite to each other in the extending direction thereof.

Valve lifter structure

An apparatus for controlling valve performance in an engine is disclosed. A first detection blade helically extends on a camshaft. A pair of second detection blades are located on the camshaft and extend axially on the camshaft. An electromagnetic pickup is arranged to face the camshaft. The pickup produces a pulse in response to one of the blades passing by the pickup when the camshaft rotates. ECU computes the axial position of the camshaft based on the change in the time period from the pulse corresponding to the second blade to the pulse corresponding to the first blade.

Variable valve performance apparatus for engine

A valve characteristic control apparatus is provided with a simple structure in which a cam shaft having three-dimensional cams is axially displaced and the cam shaft is rotated with respect to a crank shaft by a ring gear. An axial driving mechanism axially displaces the intake cam shaft and thereby changes working angles of the three-dimensional cams. In this case, engagement of a spline formed on the cam shaft with teeth formed on an inner peripheral surface of the ring gear allows the cam shaft to axially move with respect to a pulley integrated with the crank shaft. A rotational driving mechanism axially displaces the ring gear, so that a helical spline formed on the pulley engages teeth formed on an outer peripheral surface of the ring gear and a spline formed on the cam shaft engages teeth formed on the inner peripheral surface of the ring gear. Thus, the cam shaft rotates relative to the pulley.

Valve control apparatus for an internal combustion engine

A valve drive device has a pair of valves in association with a cylinder and a pair of cams provided on the camshaft to selectively open and close the valves. Each cam has a cam surface and a cam nose. The cam surface has an axially varying radius at the cam nose. A bearing supports the camshaft between the pair of cams. A pair of valve lifters are arranged respectively between the cams and the valves. Each valve lifter has a supporting surface and a cam follower supported on the supporting surface to slidably contact with the cam surface. A moving mechanism moves axially to change the lift amount of the valves, Each cam follower is located farther from the bearing, which is positioned between the pair of cams, than the center of the supporting surface in the axial direction of the camshaft. This results in greater axial movement of the cams and a greater variation of valve lift without placing excessive axial lodes on the camshaft.

Variable engine valve driver

A variable valve timing mechanism of an internal combustion engine varies the rotational phase of a camshaft with respect to a drive shaft to vary the timing of a set of engine valves. The mechanism includes a first rotor for a rotation in synchronism with the drive shaft and a second rotor for a rotation in synchronism with the camshaft. The second rotor has vanes, which are located in hydraulic chambers. Unequal hydraulic forces on the vanes causes the second rotor to rotate with respect to the first rotor to change the rotational phase of the camshaft with respect to the drive shaft. Hydraulic pressure is supplied to a certain side of the vanes to apply forces to the vanes. A lock member locks the second rotor to the first rotor to fix the rotational phase of the camshaft with respect to the drive shaft. The lock member unlocks the second rotor from the first rotor only when the hydraulic pressure supplied to the vanes is such that the torque produced by the hydraulic pressure on the vanes is at least as great as an oppositely directed torque resulting from rotational fluctuation of the camshaft. This prevents the vanes from colliding against the walls of their chambers, which produces noise.

Variable valve timing mechanism for internal combustion engine

In a rear engined or mid engined type of automotive vehicle in which a liquid cooled internal combustion engine is mounted at least partly behind a passenger compartment, and a radiator for cooling the cooling fluid of the engine is mounted in front of the passenger compartment, with a mechanism being provided for conducting flow of cooling fluid between the cooling fluid jacket of the engine and the radiator in both directions, a cooling system for lubricating oil of the engine includes a heat exchanger formed with a cooling fluid passage and a lubricating oil passage arranged to exchange heat therebetween to conduct respectively a flow of cooling fluid and a flow of lubricating oil from the internal combustion engine, wherein the cooling fluid passage of the heat exchanger is a part of the cooling fluid flow conducting mechanism, so as not to the heat exchanger without substantially increasing the flow resistance of the cooling fluid flow conducting mechanism. Optionally, the cooling fluid passage and the lubricating oil passage of the heat exchanger may be provided by a plurality of coaxially arranged cylinders wherein the cooling fluid and the lubricating oil flowing axially through the respective cylindrical passages are brought into mutual heat exchange across a cylindrical heat conducting separating wall.

Lubricating oil cooling system for rear or mid engined vehicle

A sealing structure including a substantially flat sealing surface, a gasket and a groove formed in a flange facing the sealing surface for the gasket and for applying a sealing force to the gasket in a direction substantially perpendicular to the sealing surface. A groove is formed such that the groove has inclined surfaces with the width of the groove increasing towards the sealing surface and such that the inclined surfaces apply a pressing force to the gasket.

Growing community of inventors

Toyota, Japan

Tadao Hasegawa