1. Field of the Invention
The present invention relates to a vehicle transmission including a main shaft to which power from an engine can be transmitted. A counter shaft connected to drive wheels. A plurality of change gear stages of gear trains are provided between the main shaft and the counter shaft. Shifters are relatively non-rotatably and slidably borne on the main shaft or the counter shaft so as to change over the establishment conditions of the gear trains. A shift drum is provided at its outer periphery with lead grooves for engagement with shift forks rotatably holding the shifters. A shift drum center is turned together with the shift drum. An intermittent feed mechanism intermittently turningly drives the shift drum center. The transmission of power from the engine to the main shaft is interrupted when the shifters are slid so as to change over the establishment conditions of the plurality of change gear stages of the gear trains.
2. Background of the Invention
A vehicle transmission, wherein the establishment conditions of a plurality of change gear stage of gear trains are changed over by intermittently turningly driving a shift drum center turned together with a shift drum, has been known as described, for example, in Japanese Patent Laid-open No. Hei 7-317881.
However, the intermittent feed mechanism in the vehicle transmission disclosed in Japanese Patent Laid-open No. Hei 7-317881 is so configured that the drum shifters are turningly driven at the same turning speed by a predetermined angle at the time of changing over the establishment conditions of the plurality of change gear stages of gear trains. Therefore, when the shifters are slid so as to change over the establishment conditions of the gear trains, the difference in speed between the shifter and the gear to be engaged with the shifter would be comparatively large, so that the engaging sound would be large. Particularly, in that type of a vehicle with the change gear stage changed over according to shift-up and shift-down operations in which a preliminary speed change is conducted during running at a change gear stage, a large engaging sound that is not in conjunction with the driver's operation would be generated, making the driver feel a sense of incompatibility.