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A shift control apparatus of an automatic transmission of a motor vehicle to which torque is transmitted from an engine via a fluid coupling device is provided. In the automatic transmission including a plurality of hydraulically operated friction elements, a clutch-to-clutch downshift is carried ou

A shift control apparatus of an automatic transmission of a motor vehicle to which torque is transmitted from an engine via a fluid coupling device is provided. In the automatic transmission including a plurality of hydraulically operated friction elements, a clutch-to-clutch downshift is carried out during coasting of the vehicle by releasing one of the friction elements and engaging another friction element. A controller of the shift control apparatus detects a difference between input and output rotation speeds of the fluid coupling device, and increases an engine speed by a controlled amount based on the difference between the input and output rotation speeds when the clutch-to-clutch downshift is carried out during coasting of the vehicle, so that the vehicle is brought into a minimal driving state in which the engine speed is slightly higher than the output rotation speed of the fluid coupling device.

대표청구항 ▼

A shift control apparatus of an automatic transmission of a motor vehicle to which torque is transmitted from an engine via a fluid coupling device is provided. In the automatic transmission including a plurality of hydraulically operated friction elements, a clutch-to-clutch downshift is carried ou

A shift control apparatus of an automatic transmission of a motor vehicle to which torque is transmitted from an engine via a fluid coupling device is provided. In the automatic transmission including a plurality of hydraulically operated friction elements, a clutch-to-clutch downshift is carried out during coasting of the vehicle by releasing one of the friction elements and engaging another friction element. A controller of the shift control apparatus detects a difference between input and output rotation speeds of the fluid coupling device, and increases an engine speed by a controlled amount based on the difference between the input and output rotation speeds when the clutch-to-clutch downshift is carried out during coasting of the vehicle, so that the vehicle is brought into a minimal driving state in which the engine speed is slightly higher than the output rotation speed of the fluid coupling device. of a bottom surface of the water muffler.8. The exhaust system for a boat according to claim 2, wherein the water muffler includes a communication hole between the expansion chamber and the resonator chamber for allowing said cooling water to flow between the expansion chamber and the resonator chamber.9. The exhaust system for a boat according to claim 2, wherein a downstream end of the water lock pipe is connected to a resonator through a tail pipe.10. An exhaust system for a boat comprising: a tube-shaped water muffler having an axis aligned parallel to a length of the boat, the water muffler being disposed between two sections of an exhaust pipe and rearwardly from an engine provided in a hull of the boat; and a water lock pipe having an inverted U-shape extending upward from a middle portion of said water muffler for discharging exhaust gas out of the boat, wherein a resonator chamber for attenuating resonance of the water lock pipe is provided in the water muffler. 11. The exhaust system for a boat according to claim 10, further comprising an expansion chamber in the water muffler, wherein the expansion chamber and the resonator chamber are able to communicate with each other by a communication pipe, said communication pipe being disposed above an upper surface of cooling water in the water muffler.12. The exhaust system for a boat according to claim 11, wherein the water lock pipe includes an inlet port having an opening at