Honda Giken Kogyo Kabushiki Kaisha

Honda Motor Co., Ltd.

Sei Watanabe

Shohei Kono

Takao Nishida

Keita Ito

Yoshikazu Yamada

Yasuhiro Shimizu

Gaku Naoe

Toru Kawai

Yoshikazu Sato

Hayato Matsuda

Kazuyuki Shiomi

Mashu Kurata

Akihisa Shinoda

In a premixed compression self-ignition engine which is compact but capable of exerting a high output, an intermediate portion of a trigonal link is rotatably supported on a crankpin, a large end portion of a connecting rod is connected to one end portion of the trigonal link, and a swing link swingably supported on a fulcrum shaft is connected to another end portion of the trigonal link. The engine includes: an intake port open to a crank chamber; a reed valve mounted in the intake port; a scavenging port configured to guide fresh air from the crank chamber into a cylinder bore in a downward stroke of a piston; an exhaust port provided in a cylinder head and open to a top portion of the cylinder bore; and an exhaust valve configured to be opened before the piston opens the scavenging port in the downward stroke of the piston.

Premixed compression self-ignition engine

In a link type variable stroke engine in which a piston, a crankshaft and an eccentric shaft are linked by a linking mechanism, a counterweight part which is provided so that in a projection view on a plane orthogonal to an axis of a rotary shaft, a center of gravity of the counterweight part is located on an opposite side of the axis of the rotary shaft from an axis of the eccentric shaft rotates together with the rotary shaft. Accordingly, it is possible to effectively suppress and lessen half-order inertial exciting force occurring at the eccentric shaft.

Link type variable stroke engine

In a link type variable stroke engine in which a piston, a crankshaft and an eccentric shaft are linked by a linking mechanism, counterweights are provided on the crankshaft so that in a projection view on a plane orthogonal to a rotation axis of the crankshaft, centers of gravity of the counterweights are located on a straight line extending from the rotation axis of the crankshaft in an opposite direction to a direction of a total inertial exciting force when the total inertial exciting force becomes maximum, the total inertial exciting force being obtained by adding inertial exciting forces occurring respectively in movable components of the linking mechanism. Accordingly, it is possible to effectively suppress and lessen inertial exciting force.

In a link type variable stroke engine in which: a crankshaft and a rotary shaft having an eccentric shaft are each rotatably supported on a case main body formed integrally with a cylinder block and opened at one side to form a part of a crankcase, and a support plate fastened to an opened end of the case main body at a plurality of positions; and a piston, the crankshaft and the eccentric shaft are linked by a linking mechanism, in a projection view on a plane orthogonal to axes of the crankshaft and the rotary shaft, two of the plurality of fastening positions at which the support plate is fastened to the opened end of the case main body are disposed on a straight line passing the axes of the rotary shaft and the crankshaft. This configuration can increase the rigidity between the crankshaft and the rotary shaft enough to prevent change of the distance between the crankshaft and the rotary shaft.

A variable stroke engine includes an end portion of a connecting rod, which is connected at one end portion thereof to a piston by a piston pin, and an end portion of a control rod, which is connected at one end portion thereof to an eccentric shaft, and which are linked to each other by a link member rotatably supported on a crankshaft. A rotative power of the crankshaft is transmitted to the camshaft. The camshaft is disposed at such a position that part of a trajectory drawn by the intake-side and exhaust-side cams overlaps a trajectory drawn by the link member in a projection on a plane perpendicular to an axis of the crankshaft, and a rotational phase of the camshaft is set so that the interference, of the intake-side and exhaust-side cams with an end portion, on the camshaft side, of the link member, is avoided.

Variable stroke engine

A variable stroke engine has a crankshaft, a camshaft, and a rotational shaft, having an eccentric shaft, which are rotatably supported in a crankcase so as to have axes parallel to one another. A connecting rod is connected, at one end portion thereof, to a piston by a piston pin, and a control rod is connected, at one end portion thereof, to the eccentric shaft. The other end portion of the connecting rod and the other end portion of the control rod are linked to each other by a link member rotatably supported on the crankshaft. A rotative power of the crankshaft is transmitted to the camshaft and the rotational shaft, respectively. A timing driving wheel transmitting the rotative power to the camshaft side is mounted on the crankshaft, and a timing driven wheel driven by the timing driving wheel is mounted on the rotational shaft.

In a stroke-variable engine, the position of a center of gravity of a subsidiary connecting rod is determined so that a distance between the position of the center of gravity of the subsidiary connecting rod and an axis of a crankpin is smaller than a distance between a point of connection of a main connecting rod to the subsidiary connecting rod and the position of the center of gravity as well as a distance between a point of connection of a control rod to the subsidiary connecting rod and the position of the center of gravity. Thus, 0.5-order vibration generated in the subsidiary connecting rod is lowered, engine vibration is suppressed, and noise generated with the vibration is suppressed.

Stroke-variable engine

A stroke-variable engine includes a pivot shaft which is rotatably supported in a crankcase so as to be rotatable about an eccentric axis parallel to a crankshaft and which is connected to a control rod so that a rotational power reduced at a reduction ratio of 1/2 is transmitted from the crankshaft to the pivot shaft. A camshaft of a valve-operating mechanism mounted at an upper portion of an engine body and the pivot shaft are operatively connected to each other. Thus, it is possible to decrease the number of parts of the valve-operating mechanism, increase a rotational speed, and further reduce mechanical noise.

A variable stroke engine includes a connecting rod having one end thereof connected to a piston via a piston pin. A sub-rod is connected to a crankshaft via a crankpin and to the other end of the connecting rod. A control rod has one end thereof connected to the sub-rod at a position distal from the position where the sub-rod is connected to the connecting rod. An eccentric shaft is connected to the other end of the control rod. The eccentric shaft is provided at a position eccentric relative to a rotating shaft to which power is transmitted from the crankshaft at a reduction ratio of &#xbd;. Intake and exhaust cams form a part of a valve operating mechanism and are provided on the rotating shaft.

An engine with a variable compression ratio includes a connecting rod connected to a piston, a first arm turnably connected to the connecting rod and to a crankshaft through a crankpin, a second arm integrally connected to the first arm, a control rod turnably connected to the second arm, and a displaceable support shaft for supporting the other end of the control rod for turning movement. In the engine, a displacement Vhpivand a compression ratio &#x3b5;pivat the time when the support shaft is in any first position and a displacement Vhpivand a compression ratio &#x3b5;pivat the time when the support shaft is in a second position displaced from the first position are determined, and a relation, Vhpiv&#x3e;Vhpivis satisfied when &#x3b5;piv&#x3c;&#x3b5;piv, and a relation, Vhpiv&#x3c;Vhpivis satisfied when &#x3b5;piv&#x3e;&#x3b5;piv

Engine with variable compression ratio

The present invention relates to an engine in which the stroke of a piston at an expansion stroke is larger than that at a compression stroke. In order to ensure that a top dead center at each of intake and exhaust strokes and a top dead center at the compression stroke are at the same level, the following dimensions are determined according to an equation representing a level of a piston pin, so that the top dead center at each of the intake and exhaust strokes and the top dead center at the compression stroke are congruous with each other: a length of a second arm; a length of a first arm; a length of a control rod; a length of a connecting rod; a length from an axis of a crankshaft to axes of rotary shafts in a direction of a y-axis; a length from the axis of the crankshaft to the axes of the rotary shafts in a direction of an x-axis; an amount of offsetting of a cylinder axis from the axis of the crankshaft in the direction of the y-axis; an angle formed by the first and second arms; a length between the axis of the crankshaft and the crankpin; a length of a straight line connecting the axes of the rotary shafts; and an axis of a movable eccentric shaft and an angle when a crank angle is &ldquo;0&rdquo;.

Engine

A variable compression ratio engine includes a support shaft positioned eccentrically relative to rotating shafts. A restricting projection is provided at one location in the circumferential direction on the rotating shafts so as to project outward in the radial direction. A rocker member has a pair of engagement portions with respective phases displaced from each other and which engage the restricting projection. The rocker member is spring-biased in a direction in which one of the two engagement portions engages the restricting projection and is mounted on a shaft member so as to be able to rock around the axis of the shaft member. An actuator is driven by the engine negative pressure and is connected to the rocker member so as to swing the rocker member in a direction opposite to the spring-bias direction.

Variable compression ratio engine

A throttle system for a general-purpose engine, having an actuator (motor) connected to a throttle valve to open or close it so as to regulate amount of intake air. An output transmission mechanism constituted as a link mechanism or a gear mechanism is provided between the actuator and the throttle valve to transmit an output of the actuator to the throttle value such that an output of the mechanism relative to the output of the actuator when the throttle valve is fully closed, is smaller than that when the throttle value is not fully closed. With this, the system can finely open and close the throttle valve when its opening is small and can open and close it at high speed when its opening is large, while preventing throttle valve seizing.

Throttle system for general-purpose engine

In a handheld type OHV engine, an oil tank is provided so as to be connected to one side wall running the length of a crankcase and a cylinder block, the oil tank houses oil mist generation means to and a rotational movement section of a valve operation mechanism, and the oil mist generated in the oil tank is supplied from a crank chamber to a valve operation chamber of a cylinder head housing a reciprocating movement section of the valve operation mechanism, and is returned to the oil tank by utilizing the pressure pulsations of the crank chamber and a one-way valve. It is thus possible to lubricate the inside of the crank chamber and the valve operation mechanism reliably regardless of the operational position of the handheld type OHV engine while reducing the overall height of the engine.

Handheld type four-cycle engine

In an oil mist generation system, an oil slinger is disposed in an oil tank and is rotated by a crankshaft, the oil slinger scattering oil store in the oil tank by the rotation of the oil slinger so as to generate an oil mist. The oil mist generation system includes a drive gear provided on the crankshaft, and at least three oil slingers supported on three support shafts and simultaneously driven by the drive gear, the three support shafts being arranged around the drive gear. Therefore, besides a circular shape, various shapes can be imparted to the peripheral wall of the oil tank.

Growing community of inventors

Wako, Japan

Sei Watanabe