Vehicle transmission

A vehicle transmission comprising:

• a main transmission configured to output rotational drive force generated by a power source at a predetermined gear ratio by selecting a main transmission gear position among a plurality of speed-changing gear pairs, the main transmission being an automatic transmission configured to perform gear shifting according to a gear shift map selected between a first gear shift map and a second gear shift map in accordance with a throttle opening degree and a vehicle speed;
• a sub-transmission configured to change rotational speed of the rotational drive force output from the main transmission by manually selecting a sub-transmission gear position between a drive position and a low position having a reduction ratio larger than a reduction ratio of the drive position, the first gear shift map corresponding to the drive position, the second gear shift map corresponding to the low position;
• a sub-transmission shift position sensor configured to sense the sub-transmission gear position of the sub-transmission;
• and
• a map switching device configured to perform switching between the first gear shift map and the second gear shift map in accordance with sensing signals from the sub-transmission shift position sensor.

A vehicle transmission comprising:

• a main transmission configured to output rotational drive force generated by a power source at a predetermined gear ratio by selecting a main transmission gear position among a plurality of speed-changing gear pairs, the main transmission being an automatic transmission configured to perform gear shifting according to a gear shift map selected between a first gear shift map and a second gear shift map, the gear shift map being selected in accordance with throttle opening degree and a vehicle speed;
• a sub-transmission configured to change rotational speed of the rotational drive force output from the main transmission by manually selecting a sub-transmission gear position between a drive position and a low position having a reduction ratio larger than a reduction ratio of the drive position, the first gear shift map corresponding to the drive position, the second gear shift map corresponding to the low position;
• sub-transmission shift position sensing means for sensing the sub-transmission gear position of the sub-transmission;
• and
• map switching means for performing switching between the first gear shift map and the second gear shift map in accordance with sensing signals from the sub-transmission shift position sensing means.