摘要:
A variable compression ratio internal combustion engine includes a control shaft (13) rotatably supported by an engine body, a variable compression ratio mechanism (10) for changing an engine compression ratio in accordance with a rotational position of the control shaft (13), an actuator (21) that rotatively drives the control shaft (13), and a speed reducing mechanism (22) for reducing a rotational power of the actuator (21) and for transmitting the speed-reduced power to the control shaft (13). The speed reducing mechanism (22) has a rotation shaft (24) rotatably supported in a housing (26) fixed to the engine body and a lever (25) that connects the rotation shaft (24) and the control shaft (13). Located in the engine body is a first regulation part (42) for mechanically regulating the control shaft (13) to a position of maximum rotation on one side of a low compression ratio side and a high compression ratio side. Also located in the housing (26) is a second regulation part (41) for mechanically regulating the rotation shaft (24) to a position of maximum rotation on the other side of the low compression ratio side and the high compression ratio side.
摘要:
Disclosed is a variable compression ration mechanism (5) in which a control shaft (10) is rotated and driven by an electric motor (21) through a wave gear reducer (22). The wave gear reducer (22) includes: a first internal gear member (31); an external gear member (32) arranged concentrically inside the internal gear member (31); a wave generator (33) having an oval outer shape and arranged inside the external gear member (32); and a second internal gear member (34), wherein a ratio of the number of teeth of a fixed gear portion (35) of the first internal gear member (31) to the number of teeth of a first gear portion (37) of the external gear member (32) is set greater than a ratio of the number of teeth of an output-side gear portion (42) of the second internal gear member (34) to the number of teeth of a second gear portion (38) of the external gear member (32).
摘要:
There is provided a link mechanism (22) which connects a variable compression ratio mechanism (10) arranged to vary an engine compression ratio in accordance with a rotation position of a first control shaft (13), and an actuator (20), which includes a lever (25) connecting a first control shaft (13) and a second control shaft (24), a combustion load acted to the first control shaft (13) being transmitted through the lever (25) to the second control shaft (24). There are provided: a first link pin (28) connecting a tip end of the first arm portion (27) extending from the first control shaft (13) in a radially outward direction, and one end of the lever (25) so that the first arm portion and the lever are rotated relative to each other; and a second link pin (30) connecting a tip end of the second arm portion (29) extending from the second control shaft (24) in a radially outward direction, and the other end of the lever (25) so that the second control shaft and the lever are rotated relative to each other. A diameter (D1) of the first link pin (28) is set to be greater than a diameter (D2) of the second link pin (30).
摘要:
An internal combustion engine (1) that has a variable-compression-ratio mechanism (2) has variable valve mechanisms (7, 8) for an intake valve (4) and an exhaust valve (5), respectively. If a malfunction in the variable-compression-ratio mechanism (2), which controls a mechanical compression ratio via an electric motor (31), is detected from the amplitude of variations in an actual compression ratio, then if the fuel supply to the engine is cut, a throttle valve (14) is opened wider than would be the case if the variable-compression-ratio mechanism (2) were not malfunctioning, thereby reducing in-cylinder negative pressure during the intake stroke. Also, the timing with which the intake valve is closed is advanced and the timing with which the exhaust valve is opened is retarded, increasing the in-cylinder positive pressure during the compression and power strokes. This prevents the variable-compression-ratio mechanism (2) from increasing the compression ratio when control is lost.
摘要:
Disclosed is a variable compression ration mechanism (5) in which a control shaft (10) is rotated and driven by an electric motor (21) through a wave gear reducer (22). The wave gear reducer (22) includes: a first internal gear member (31); an external gear member (32) arranged concentrically inside the internal gear member (31); a wave generator (33) arranged inside the external gear member (32); and a second internal gear member (34), wherein a ratio of the number of teeth of a fixed gear portion (35) of the first internal gear member (31) to the number of teeth of a first gear portion (37) of the external gear member (32) is set lower than a ratio of the number of teeth of an output-side gear portion (42) of the second internal gear member (34) to the number of teeth of a second gear portion (38) of the external gear member (32). Thus, the tooth depth of the output-side gear portion (42) of the second internal gear member (34) is made relatively large so as to attain a higher ratcheting torque and prevent ratcheting.
摘要:
The present invention is equipped with a variable compression ratio mechanism (10) that changes an engine compression ratio depending on the rotational position of a first control shaft (14), and an actuator that changes and holds the rotational position of the first control shaft (14). A linking mechanism linking the actuator and the first control shaft (14) has a lever (24) linked to the first control shaft (14). The tip of an arm part (25) extending radially outward from the center of the first control shaft (14) and one end of the lever (24) are rotatably linked by a first connecting pin (26). At least when having been set to the highest compression ratio, the first connecting pin (26) is submerged below an oil level (±1) of the oil pan (5).
摘要:
A variable compression ratio internal combustion engine includes a control shaft (13) rotatably supported by an engine body, a variable compression ratio mechanism (10) for changing an engine compression ratio in accordance with a rotational position of the control shaft (13), an actuator (21) that rotatively drives the control shaft (13), and a speed reducing mechanism (22) for reducing a rotational power of the actuator (21) and for transmitting the speed-reduced power to the control shaft (13). The speed reducing mechanism (22) has a rotation shaft (24) rotatably supported in a housing (26) fixed to the engine body and a lever (25) that connects the rotation shaft (24) and the control shaft (13). Located in the engine body is a first regulation part (42) for mechanically regulating the control shaft (13) to a position of maximum rotation on one side of a low compression ratio side and a high compression ratio side. Also located in the housing (26) is a second regulation part (41) for mechanically regulating the rotation shaft (24) to a position of maximum rotation on the other side of the low compression ratio side and the high compression ratio side.
摘要:
It has variable compression ratio mechanism (10) that changes engine compression ratio depending on the rotational position of first control shaft (14). First control shaft (14) and second control shaft, which is connected to a motor, are coupled together by lever (24) of coupling mechanism (20). First arm portion (25) of first control shaft (14) and one end of lever (24) are rotatably coupled together by first coupling pin (26). When viewed in the axial direction of this first coupling pin (26), at least at a given compression ratio position, first coupling pin (26) is arranged at a position away from bearing cap (30) that is for rotatably supporting first control shaft (14).
摘要:
A control device for a variable compression ratio internal combustion engine is equipped with a variable compression ratio device capable of changing an engine compression ratio of the internal combustion engine. The control device detects or estimates the temperature of an exhaust component (B11), and sets a target exhaust gas temperature based on the temperature of the exhaust component (B12). A mixing ratio and compression ratio set section (B13) sets a fuel mixing ratio and the engine compression ratio within such a range as not to exceed the target exhaust gas temperature such that energy loss becomes minimum.