Continuously variable transmission and method of controlling the same

A continuously variable transmission comprising:

• a variator which can continuously change a speed ratio;
• a sub transmission mechanism arranged in series with respect to the variator and including a first gear position and a second gear position whose speed ratio is smaller than the first gear position as gear positions:
• a synchronization shift unit configured to shift the variator in a direction opposite to a speed ratio change direction of the sub transmission mechanism when shifting the sub transmission mechanism;
• and
• a non-synchronization unit configured to prohibit synchronization shift, and shift only the sub transmission mechanism from the second gear position to the first gear position when the gear position of the sub transmission mechanism is at the second gear position and an output increase request of a power source is made.

A control method of a continuously variable transmission, wherein the continuously variable transmission comprises:

• a variator which can continuously change a speed ratio;
• and
• a sub transmission mechanism which is arranged in series with respect to the variator and which includes a first gear position and a second gear position whose speed ratio is smaller than the first gear position as gear positions, and wherein the control method comprises:
• a synchronization shift step of shifting the variator in a direction opposite to a speed ratio change direction of the sub transmission mechanism when shifting the sub transmission mechanism;
• and
• a non-synchronization shift step of, when the gear position of the sub transmission mechanism is at the second gear position and a driver makes an acceleration request, prohibiting synchronization shift, and shifting only the sub transmission mechanism from the second gear position to the first gear position.

A continuously variable transmission comprising:

• a variator which can continuously change a speed ratio;
• a sub transmission mechanism arranged in series with respect to the variator and including a first gear position and a second gear position whose speed ratio is smaller than the first gear position as gear positions;
• synchronization shift means for shifting the variator in a direction opposite to a speed ratio change direction of the sub transmission mechanism when shifting the sub transmission mechanism;
• and
• non-synchronization shift means for prohibiting synchronization shift, and shifting only the sub transmission mechanism from the second gear position to the first gear position when the gear position of the sub transmission mechanism is at the second gear position and an output increase request of a power source is made.