Abstract: An internal combustion engine is provided with a ratchet one-way clutch between an output shaft of a starting motor and a crankshaft. The one-way clutch includes a claw piece which rotates integrally with the crankshaft, and an engagement part which rotates integrally with the starting motor and with which the claw piece engages. An electronic control device performs control for driving the starting motor when the engine is stopped to reduce the difference between the rotation speed of the engine and the rotation speed of the starting motor, that is, the difference between the rotation speed of the claw piece and the rotation speed of the engagement part.

Abstract: A variable valve apparatus of an internal combustion engine includes a first rocker arm that contacts a cam, a low lift cam provided coaxially with the cam, and a second rocker arm capable of contacting the low lift cam. The apparatus also includes a switching mechanism capable of connecting the first rocker arm and the second rocker arm to each other through pins, valves that open by being pressed by the second rocker arms via hydraulic lash adjusters arranged in the second rocker arms, and an oil supply path formed inside the second rocker arms that supplies oil to the hydraulic lash adjusters. A radius of a base circle of the low lift cam is smaller than a radius of a base circle of the cam.

Abstract: An internal combustion engine is provided with a ratchet one-way clutch between an output shaft of a starting motor and a crankshaft. The one-way clutch includes a claw piece which rotates integrally with the crankshaft, and an engagement part which rotates integrally with the starting motor and with which the claw piece engages. An electronic control device performs control for driving the starting motor when the engine is stopped to reduce the difference between the rotation speed of the engine and the rotation speed of the starting motor, that is, the difference between the rotation speed of the claw piece and the rotation speed of the engagement part.

Abstract: An object of the present invention is to decrease the size of rocker arms and reduce friction in a variable valve apparatus of an internal combustion engine having a hydraulic lash adjuster arranged in rocker arms. A variable valve apparatus of an internal combustion engine of the present invention includes a first rocker arm that contacts a cam, a zero lift cam (low lift cam) provided coaxially with the cam, second rocker arms capable of contacting the zero lift cam, a switching mechanism capable of connecting the first rocker arm and the second rocker arm to each other through a pin, valves that open by being pressed by the second rocker arms via hydraulic lash adjusters arranged in the second rocker arms, and an oil supply path formed inside the second rocker arms that supplies oil to the hydraulic lash adjusters. A radius of a base circle of the zero lift cam is smaller than a radius of a base circle of the cam.

Abstract: In a variable valve mechanism, a control shaft is associated with an advance oil passage such that the same passage is closed by the control shaft when a maximum valve lift amount of an intake valve is equal to or larger than a reference lift amount. The control shaft is associated with the advance oil passage such that a range in which the control shaft displaces is limited to a range between a minimum value of the maximum valve lift amount and a lift amount just before the reference lift amount when an advance angle of the intake valve is equal to or larger than a reference advance angle.

Abstract: In a variable valve mechanism, a control shaft is associated with an advance oil passage such that the same passage is closed by the control shaft when a maximum valve lift amount of an intake valve is equal to or larger than a reference lift amount. The control shaft is associated with the advance oil passage such that a range in which the control shaft displaces is limited to a range between a minimum value of the maximum valve lift amount and a lift amount just before the reference lift amount when an advance angle of the intake valve is equal to or larger than a reference advance angle.

Abstract: A variable valve mechanism of an internal combustion engine capable of changing at least one of two valve physical quantities, i.e., valve operation angle and valve lift, has a valve lift adjustment mechanism that adjusts the at least one valve physical quantity with a higher precision in a region where the at least one valve physical quantity is relatively small than in a region where the at least one valve physical quantity is relatively large. Therefore, a size increase of the variable valve mechanism can be avoided, and the mechanism can easily be incorporated into the engine.

Abstract: A variable valve mechanism of an internal combustion engine capable of changing at least one of two valve physical quantities, i.e., valve operation angle and valve lift, has a valve lift adjustment mechanism that adjusts the at least one valve physical quantity with a higher precision in a region where the at least one valve physical quantity is relatively small than in a region where the at least one valve physical quantity is relatively large. Therefore, a size increase of the variable valve mechanism can be avoided, and the mechanism can easily be incorporated into the engine.

Abstract: The cam face of an intake cam has a main lift portion, which causes an intake valve to execute a basic lift operation, and a sub lift portion, which assists the action of the main lift portion. The main lift portion and the sub lift portion continuously change in an axial direction of the intake cam. An axial movement mechanism moves the intake cam in the axial direction to adjust the axial position of the cam face that drives the intake valve. The axial movement of the intake cam results in the valve being given a variety of valve lift characteristics in the form of a combination of a cam lift pattern realized by the main lift portion and a cam lift pattern realized by the sub lift portion. Therefore, various engine performances required according to the running conditions of the engine can be fully satisfied by the valve characteristics.

Abstract: A three-dimensional cam has a cam profile surface shape that changes along a rotating axis of the cam, and is produced by net-shape-sintering. The sintered density of a sintering material at the time of net-shape-sintering is set to 7 to 7.4 g/cm3 to achieve a hole rate of the cam profile surface within the range of 5 to 10%. The three-dimensional cam has an improved durability, while securing high productivity.

Abstract: A valve train for an internal combustion engine has a variable valve performance mechanism for changing the valve open angle of at least one set of intake valves and exhaust valves. The valve train further includes an electronic control unit (ECU) for controlling the variable valve performance mechanism and a sensor for detecting the running state of the engine. The ECU judges whether there is a malfunction in the engine based on detection signals from the sensor. If there is a malfunction in the engine, the ECU actuates the variable valve performance mechanism to decrease the valve overlap thereby performing a failsafe. The ECU also advances the closing timing of the intake valves. Alternatively, the ECU retards the opening timing of the exhaust valves.

Abstract: A variable valve apparatus of an internal combustion engine is capable of realizing more precise valve characteristic control by reducing the error in-detection of the amount of movement of a camshaft caused by a difference in the rate of thermal expansion. The variable valve apparatus has a camshaft that is supported so as to be rotatable and slidable in a direction of an axis thereof and that has three-dimensional cams whose cam profile continuously changes in the direction of the axis. The apparatus also has an actuator for moving the camshaft in the direction of its axis. The apparatus further has a camshaft position sensor provided in a cylinder head, a detected portion provided in the camshaft, and a camshaft movement amount detection portion for detecting the amount of movement of the camshaft in the direction of the axis. The camshaft movement amount detection portion is provided near a camshaft reference position.

Abstract: Variable valve characteristic control apparatuses realize a change in a valve characteristic in accordance with a requirement of an internal combustion engine and a three-dimensional cam for use in the variable valve characteristic control apparatus. In the case of an intake valve, two lift patterns and continuously varying lift patterns between the two lift patterns are realized by the three-dimensional cam through the driving of the variable valve characteristic control apparatus. The two lift patterns provide different amounts of lift in the delay side of a peak within a valve operation angle, but provide equal amounts of lift in the delay side of the peak. Since the intake cam has the two lift patterns, it is possible to select a phase where the two lift patterns provide equal amounts of lift and provide different amounts of lift in phases other than the equal-lift phase so as to accord to the characteristics of the internal combustion engine.

Abstract: Variable valve characteristic control apparatuses realize a change in a valve characteristic in accordance with a requirement of an internal combustion engine and a three-dimensional cam for use in the variable valve characteristic control apparatus. In the case of an intake valve, two lift patterns and continuously varying lift patterns between the two lift patterns are realized by the three-dimensional cam through the driving of the variable valve characteristic control apparatus. The two lift patterns provide different amounts of lift in the delay side of a peak within a valve operation angle, but provide equal amounts of lift in the delay side of the peak. Since the intake cam has the two lift patterns, it is possible to select a phase where the two lift patterns provide equal amounts of lift and provide different amounts of lift in phases other than the equal-lift phase so as to accord to the characteristics of the internal combustion engine.

Abstract: A valve train for an internal combustion engine has a variable valve performance mechanism for changing the valve open angle of at least one set of intake valves and exhaust valves. The valve train further includes an electronic control unit (ECU) for controlling the variable valve performance mechanism and a sensor for detecting the running state of the engine. The ECU judges whether there is a malfunction in the engine based on detection signals from the sensor. if there is a malfunction in the engine, the ECU actuates the variable valve performance mechanism to decrease the valve overlap thereby performing a failsafe. The ECU also advances the closing timing of the intake valves. Alternatively, the ECU retards the opening timing of the exhaust valves.

Abstract: Variable valve characteristic control apparatuses realize a change in a valve characteristic in accordance with a requirement of an internal combustion engine and a three-dimensional cam for use in the variable valve characteristic control apparatus. In the case of an intake valve, two lift patterns and continuously varying lift patterns between the two lift patterns are realized by the three-dimensional cam through the driving of the variable valve characteristic control apparatus. The two lift patterns provide different amounts of lift in the delay side of a peak within a valve operation angle, but provide equal amounts of lift in the delay side of the peak. Since the intake cam has the two lift patterns, it is possible to select a phase where the two lift patterns provide equal amounts of lift and provide different amounts of lift in phases other than the equal-lift phase so as to accord to the characteristics of the internal combustion engine.

Abstract: A valve train for an internal combustion engine has a variable valve performance mechanism for changing the valve open angle of at least one set of intake valves and exhaust valves. The valve train further includes an electronic control unit (ECU) for controlling the variable valve performance mechanism and a sensor for detecting the running state of the engine. The ECU judges whether there is a malfunction in the engine based on detection signals from the sensor. If there is a malfunction in the engine, the ECU actuates the variable valve performance mechanism to decrease the valve overlap thereby performing a failsafe. The ECU also advances the closing timing of the intake valves. Alternatively, the ECU retards the opening timing of the exhaust valve.

Abstract: A valve lifter for a three-dimensional cam and a variable valve operating apparatus have enhanced flexibility in the design of a detent mechanism of the valve lifter for the three-dimensional cam, as well as enhanced durability. It is possible to form a thick wall portion which is sufficiently thick without increasing the weight by providing an offset between an outer peripheral surface and an inner peripheral surface of the valve lifter. Therefore, a sufficiently large projection can be mounted without deforming the valve lifter. This structure makes it possible to increase an area contacting a detent groove, reduce the surface pressure, and enhance the durability. The thick wall portion exists longer in an axial direction of the valve lifter, so the detent mechanism can be formed on the outer peripheral surface instead of a top surface. Therefore, the flexibility of design of the detent mechanism can be enhanced.

Abstract: A rocking follower mechanism for a three-dimensional cam is provided. The rocking follower mechanism prevents a hit sound without generating excessive abrasion on a cam follower or a cam surface of the three-dimensional cam, while providing a wide portion for the cam follower. The cam follower is restricted from moving in the axial direction. The wide portion of the cam follower is formed at a position so as not to be brought into contact with the cam surface of the intake cam. As a result, collision of the cam surface against an angular portion defined by a thrust surface and an end surface of the wide portion, i.e., direct abutment against the end surface, can be avoided. Therefore, it is possible to prevent the hit sound without generating excessive abrasion on the cam surface of the intake cam or the cam follower itself. Accordingly, excellent riding comfort of the vehicle can be maintained.

Abstract: A cam follower mechanism for transmitting the movement of a three-dimensional cam to an intake valve. The cam operates a valve through a cam follower mechanism. A valve lifter includes a guide groove having an arcuate cross section. A cam follower is received in the guide groove and engages the cam. The cam follower can pivot about a pivoting axis. The cam follower has an arcuate cross section. The follower includes tapered surfaces, which are inclined less than ninety degrees with respect to the pivoting axis. Contact between the tapered surfaces and the guide groove prevents the cam follower from moving in the direction of the pivoting axis.