Honda Motor Co., Ltd.

Honda Giken Kogyo Kabushiki Kaisha

Akiyuki Yonekawa

Noriaki Fujii

Katsunori Nakamura

Yuji Yasui

Keiko Yoshida

Tomoya Fujimoto

Masahiko Tashiro

Tadaharu Shoji

Mitsunobu Saito

Hisao Sakai

Seiji Mori

Masaki Nagakura

Tohru Ohta

Takahumi Mizorogi

Kazunari Kaneshima

Motohiro Maruyama

Yousuke Kohara

Ryou Horiuchi

Ayako Saito

Naohiro Ishikawa

A variable valve lift device of an internal combustion engine having a first link arm rotatably supported at a fixed position of an engine body rotatably connected to a rocker arm, and a movable support shaft rotatably supporting one end portion of a second link arm of which an other end portion rotatably connected to the rocker arm is connected to a crank member formed in a crank shape having crank webs sandwiching the second link arm from opposite sides and a connecting part integrally joining both the crank webs at a position where interference with the second link arm is avoided. The crank member is rotationally driven with a drive device and an amount of lift of an engine valve is continuously changed, in addition to which, torsional rigidity of the crank member is ensured while ensuring assembly workability of the second link arm to the crank member, and reduction in size is made possible.

Variable valve lift device of internal combustion engine

A control system which is capable of compensating for and suppressing the influence of a periodic disturbance on a controlled object more quickly, even when the controlled object is subjected to the periodic disturbance the amplitude of which periodically changes, thereby enhancing the stability and the accuracy of control. The control system includes an ECU. The ECU calculates disturbance compensation values for compensating for a periodic disturbance by searching maps and tables, in timing of generation of each pulse of a CRK signal. The ECU calculates control inputs at a predetermined control period, with predetermined control algorithms, according to the disturbance compensation values read in at the control period, respectively.

Control system

A rocker arm () is provided with a valve connecting portion () into which tappet screws () abutting against a pair of engine valves () are screwed so that their advance/retract positions can be adjusted, and the rocker arm () has a cam abutting portion () which abuts against a valve operating cam () and is interlocked and connected to the engine valves (). The rocker arm () turnably connects to one end of a first link arm () turnably supported at a fixed position of an engine body and to one end of a second link arm turnably supported by a displaceable movable support shaft (). The rocker arm () is formed so that the valve connecting portion () has a larger width in a direction along a rotating axis of the valve operating cam () than in the remaining part. This enables the lift amount of the engine valves to be continuously varied. It is also possible to reduce the size of the system, while ensuring follow-up ability of the opening/closing operations.

Engine valve operating system

An engine valve operating system is provided in which one end of a first link arm () turnably supported at a fixed position of an engine body and the other end of a second link arm () turnably supported by a displaceable movable shaft () are turnably connected to a rocker arm () which has a cam abutting portion () abutting against a valve operating cam () and is interlocked and connected so as to apply a force in a valve opening direction to an engine valve () biased by a valve spring () in a valve closing direction. A rocker arm biasing spring () which is different from the valve spring () biases the rocker arm () in a direction in which the cam abutting portion () abuts against the valve operating cam (). This ensures follow-up ability of the opening/closing operations and enables a reduction in the size of the system, while allowing the lift amount of the engine valve to vary continuously. It is also possible to improve the accuracy with which the lift amount is controlled when the engine valve is to be slightly opened.

In an engine having a cylinder head which forms a portion of an engine body and is provided with an intake valve operated for opening and closing operations by an intake valve operating device having an intake camshaft and an exhaust valve driven for opening and closing operations by an exhaust valve operating device having an exhaust camshaft, the intake camshaft () is placed higher in position than the exhaust camshaft () by increasing the distance between the intake camshaft () and a combustion chamber () along a cylinder axis (C) of the engine body () relative to that between the exhaust camshaft () and the combustion chamber (). Lubricating oil is thereby enabled to be easily used for exhaust valve operating device after being used for lubrication and cooling of the intake valve operating device, thus achieving efficient lubrication and cooling of the exhaust valve operating device.

Engine

An engine valve operating system is provided in which a rocker arm () linked and connected to an engine valve () and has a cam-abutting portion () to abut a valve operating cam () is turnably connected, via first and second connecting shafts (), to one end of a first link arm () turnably supported on an engine body () and one end of a second link arm () turnably supported by a displaceable movable shaft (). Also, oil supply means () which supply oil to the upper connecting shaft () of first and second connecting shafts () are fixed to the engine body (). This makes it possible to implement an engine valve operating system which is compact in size, ensures follow-up ability of the valve opening/closing operation, has a simple lubricating structure with a reduced number of parts, and ensures smooth valve operation while allowing the lift amount of the engine valve to be varied continuously.

In an engine in which a lift amount of a valve can be changed continuously, an engine valve operating system including a valve lift-changing mechanism is capable of increasing and decreasing the lift amount of the valve without changing an opening angle for the valve and capable of decreasing a tappet clearance in accordance with a decrease in lift amount of the valve. Thus, it is possible to prevent the ratio of the tappet clearance to the lift amount at a low valve lift from being increased to minimize the influence of the dispersion of the tappet clearance and to reduce the seating speed of the valve at the low valve lift to prevent the generation of a noise. It is also possible to prevent a reduction in performance of the engine at a high valve lift due to the dispersion of the tappet clearance and to decrease the seating noise of the valve at the low valve lift.

Valve-moving device for engine

An intake air amount control system for an internal combustion engine, which is capable of ensuring high robustness and improving controllability in intake air amount control, to thereby improve drivability and reduce exhaust emissions. A control system of an internal combustion engine, which variably controls the amount of intake air drawn into cylinders as desired via a variable intake valve actuation assembly includes an ECU. The ECUcalculates a cylinder intake air amount Gcyl and a target intake air amount Gcyl_cmd based on a controlled object model, a vector &#x3b8;s of all model parameters of the controlled object model with an identification algorithm, calculates a target auxiliary intake cam phase &#x3b8;msi_cmd based on the vector &#x3b8;s with a sliding mode control algorithm, and controls the variable intake valve actuation assembly according to the target auxiliary intake cam phase &#x3b8;msi_cmd.

Intake air amount control system for internal combustion engine and control system

An engine valve operating system is provided that includes a variable valve lift mechanism in which, when there is a possibility that the rotational speed of the engine might increase beyond an allowed rotational speed due to a downshift error in a manual transmission, etc., the amount of valve lift is decreased without changing the opening angle of the valve (). By so doing, the curvature at the top of the curve of lift of the valve () is reduced, the inertial force applied to the valve () is reduced, and improper movement of the valve () can be prevented. Moreover, it is possible to prevent any increase in the intake air volume due to a decrease in the amount of lift of the valve (), and prevent the effectiveness of engine braking from being degraded, thus enabling the rotational speed of the engine to be decreased and thereby preventing improper movement of the valve () from being promoted.

Valve moving device for engine

A lift-variable valve-operating system for an internal combustion engine, comprising: subsidiary cams which are swingably supported on a movable support shaft capable of being displaced within a plane perpendicular to a rotational axis of a valve-operating cam, and which are swung following the valve-operating cam; and rocker arms each operatively connected to an engine valve and operated following the subsidiary cams, operating characteristics including a lift amount of the engine valve being changed by displacing the movable support shaft, wherein the system further includes a control arm carried in an engine body to be capable of turning about a turning axis parallel to a rotational axis of the valve-operating cam, wherein the movable support shaft having an axis parallel to the turning axis of the control arm is retained on the control arm at a location offset from the turning axis, wherein a hydraulic tappet is mounted in the control arm to support one end of each of the rocker arms, and wherein a valve abutment portion provided at the other end of each of the rocker arms is in abutment against an upper end of a stem of the engine valve. Thus, it is possible to enhance the control accuracy in a state in which the lift amount of the engine valve is controlled to be low.

Lift-variable valve-operating system for internal combustion engine

First and second connecting portionsandare arranged in parallel and relatively turnably connected to a rocker armand a movable support portionof a second link armis placed nearer to an engine valvethan a fixed support portionof a first link arm. This makes it possible to decrease the size of a valve operating system and ensure the follow-up ability of the opening/closing operation as well as to vary a lift amount of the engine valve continuously while maintaining the reliability and durability of drive means.

A valve timing control system for an internal combustion engine, which is capable of accurately and delicately controlling an amount of intake air, and thereby maintaining excellent combustion state and reduced exhaust emissions. The valve timing control system variably controls the valve-closing timing of an intake valve with respect to valve-opening timing of the same as desired via a variable intake valve actuation assembly. The ECU of the engine determined a basic value of a target auxiliary intake cam phase according to the demanded drive torque of the engine. The ECU calculates a control input to the variable intake valve actuation assembly such that the cylinder intake air amount converges to a target intake air amount and at the same time the auxiliary intake cam phase is constrained to the basic value of the target auxiliary intake cam phase.

Growing community of inventors

Wako, Japan

Akiyuki Yonekawa