Speed change control device for automatic transmission and control method thereof

A speed change control method for an automatic transmission, including a manual speed change mode in which switching between a plurality of gear positions is performed in accordance with a driver operation, the method comprising:

• upshifting a gear position when a rotation speed of an input shaft of the transmission exceeds a predetermined high rotation speed;
• determining a request to downshift the gear position of the transmission exists during traveling in the manual speed change mode;
• calculating the input shaft rotation speed of the transmission following a downshift based on the downshift request;
• determining the calculated rotation speed is higher than a rotation speed limit value set on a lower rotation side than the predetermined high rotation speed;
• and
• performing a downshift to a gear position at which the input shaft rotation speed of the transmission is lower than the calculated rotation speed when it is determined that the calculated rotation speed is higher than the rotation speed limit value,
• wherein the performing a downshift performs a downshift to a gear position at which the input shaft rotation speed of the transmission is lower than the rotation speed limit value when it is determined that the calculated rotation speed is higher than the rotation speed limit value.

A speed change control device for an automatic transmission, including a manual speed change mode in which switching between a plurality of gear positions is performed in accordance with a driver operation, the device comprising:

• auto upshift means for upshifting a gear position when a rotation speed of an input shaft of the transmission exceeds a predetermined high rotation speed;
• downshift request determining means for determining a request to downshift the gear position of the transmission exists during traveling in the manual speed change mode;
• rotation speed determining means for calculating the input shaft rotation speed of the transmission following a downshift based on the downshift request, and determining the calculated rotation speed is higher than a rotation speed limit value set on a lower rotation side than the predetermined high rotation speed;
• and
• downshift control means for performing a downshift to a gear position at which the input shaft rotation speed of the transmission is lower than the calculated rotation speed when it is determined that the calculated rotation speed is higher than the rotation speed limit value;
• wherein the downshift control means is for performing a downshift to a gear position at which the input shaft rotation speed of the transmission is lower than the rotation speed limit value when it is determined that the calculated rotation speed is higher than the rotation speed limit value.