Honda Motor Co., Ltd.

Honda Giken Kogyo Kabushiki Kaisha

Other

Katsunori Nakamura

Noriaki Fujii

Akiyuki Yonekawa

Keiko Yoshida

Tomoya Fujimoto

Hiroo Shimada

Hisao Sakai

Shigeru Aoki

Kazuhiro Ueda

Atsushi Kato

Toshiyuki Nishida

Masakatsu Miyao

Ryuichi Noseyama

Kenichiro Ishibashi

Narutoshi Sugita

Kazuo Inoue

Noriyuki Kishi

Osamu Suzuki

Tsuneo Konno

Hiroshi Sono

Yoshikazu Oshima

Kenichi Nagahiro

Seiichi Hosogai

Shigeo Hidai

Mitsuru Ikeo

Masaki Nagakura

Hiroshi Matsuzaki

Hiroshi Kubota

Akira Murakami

Tadaharu Shoji

Eisaku Gosho

Hiroyuki Fujita

Nobuo Arai

Tetsuo Gotou

Kazunari Kaneshima

Yasunori Ogita

Motohiro Maruyama

Hirotsugu Maeda

Harumi Taketomi

Yousuke Kohara

Yoshikazu Ohshima

Ryou Horiuchi

Mineko Nakamura

Teppei Ookawa

Keiji Suzuki

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 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 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

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 hydraulic tappet including: a bottomed cylindrical body; a plunger slidably fitted in the body; a check valve mounted at one end of the plunger so that the check valve is interposed between a high-pressure chamber and an oil chamber, the high-pressure chamber being formed between a closed end of the body and one end of the plunger, the oil chamber being formed within the plunger; and a return spring mounted between the body and the plunger to bias the plunger in a direction to increase the volume of the high-pressure chamber. The return spring is disposed outwardly of the body. Thus, it is possible to decrease the volume of the high-pressure chamber to provide a reduction in size of the hydraulic tappet.

Hydraulic tappet

In an internal combustion engine including a valve actuating mechanism, a vibration control member made of vibration control alloy is interposed in a path of vibration transmission between a camshaft and a cylinder head. The vibration control alloy has a vibration isolation capability comparable to that of rubber, but provides a durability and a resistance to degradation comparable to those of metal and alloy that are typically used in internal combustion engines. Therefore, a desired vibration control can be achieved while ensuring a required reliability, durability and resistance to degradation. The present invention is particularly useful when the valve actuating mechanism is provided with a variable lift, variable timing or variable compression mechanism because such a variable mechanism increases the stress to the engine, and tends to cause more vibrations than a more conventional non-variable valve actuating mechanism.

Vibration control arrangement for internal combustion engines

To allow both the valve lift and valve timing for an engine valve to be varied in a continuous manner, the variable valve actuating device () comprises a camshaft () rotatably supported by a fixed part of the engine and provided with a cam (), a first rocker arm () pivotally supported by a fixed part of the engine, the first rocker arm being provided with a first point () engaging a stem of an engine valve (), a drum () rotatably supported by a fixed part of the engine and at least partly surrounding the cam, a second rocker arm () having a first point () pivotally supported by the drum, a second point () adapted to engage the cam and a surface engaged by a second point () of the first rocker arm, and a control member () for selectively turning the drum over a prescribed angular range.

Variable valve actuating device

An oxygen sensor is disposed downstream from a catalyst for purifying exhaust gas from an internal combustion engine and which can suppress an influence of unburnt hydrocarbon on an output voltage. After forming a platinum thin film on the outer periphery of a zirconia ceramic body, only a detection electrode of the ceramic body is dipped in a silver nitrate aqueous solution of 0.1 mol/l, and the silver nitrate is pyrolyzed through a heat treatment. Subsequently, a platinum reference electrode is formed on the inner periphery of the ceramic body. To protect the silver-doped detection electrode, a protective layer is formed on the surface of the detection electrode. By the exposure to combustion gas and through aging, a detection element is formed, and set into a metal case together with a cylindrical heater, to complete an oxygen sensor to be disposed downstream from a CNG engine catalyst.

Oxygen sensor

Supply of fuel is stopped when fuel pressure sensed by a pressure sensor provided upstream of a regulator is at a predetermined value or less to avoid abnormal combustion caused by improper adjustment of air/fuel ratio. Even slight variation of the fuel pressure is sensed by monitoring the fuel pressure in an interval after closing a fuel shut-off valve once opened to re-opening of it. In addition, an abnormal state in the fuel system is detected by comparing an accumulated value of amount of injected fuel and an estimated value of fuel consumption in the tank. Furthermore, the peak current value of the fuel injection valve is controlled so that, when the engine at a low temperature is started, lift load of the injection valve is larger than sticking force of the injection valve, thereby preventing such situation where the injection valve is frozen so that it cannot supply fuel to the engine. In this case, the engine can be smoothly started by simultaneously controlling the valve open time. Furthermore, the temperature of the regulator is properly maintained so that optimum function can be exhibited by controlling the flow rate of cooling water flowing through a water passage provided in the regulator for regulating the fuel gas pressure.

Gas fuel supply system for vehicle

A fuel supply mechanism for a gas combustion engine has a tank filled with a gas fuel, a fuel injector having a fuel injection valve mounted on the gas combustion engine, a pipe for supplying the gas fuel from the tank to the fuel injector, a gas fuel cutoff valve in the pipe for cutting off the gas fuel flowing through the pipe, a gas fuel state detector for detecting a state of the gas fuel, and a control unit responsive to a detected signal from the gas fuel state detector for controlling the gas fuel cutoff valve and the fuel injection valve.

Gas fuel supply mechanism for gas combustion engine

An intake system for an internal combustion engine includes first and second intake valve bores provided to face a combustion chamber and to be independently opened and closed by first and second intake valves, and first and second intake ports which are connected to the corresponding intake valve bores with a partition wall interposed therebetween and which communicate with a common intake passage. In a particular operation range of the engine, an imbalance is produced in the concentration of the air-fuel mixture flowing through the first and second intake valve bores into the combustion chamber on the basis of a difference between the amounts of fresh air flowing into the first and second intake ports. The intake system further includes a communication hole provided in the partition wall for putting the first and second intake ports into communication with each other. This provides for improvements in the lean combustibility and in the nature of the exhaust gas.

Intake system for internal combustion engine

Growing community of inventors

Wako, Japan

Katsunori Nakamura