Operating Characteristics and Performance
SPEED CHANGE CHARACTERISTICSECVT Speed Change Characteristics:
Speed change characteristic is not linear like that of manual transmission vehicles, but is expressed as the region bounded by the maximum pulley ratio and minimum pulley ratio. In the graph, the MAX line shows the relationship between vehicle speed and engine speed at full acceleration and the MIN line shows the same relationship when accelerating slowly.
When running on a flat road at a constant speed, the engine speed changes on the MIN line and responds quickly to operation of the accelerator in the region enclosed in the bold lines.
In the full acceleration range, that is, between the speed change start point (A) and speed change end point (B) of the high engine speed range, an engine speed gradual increase versus vehicle speed change characteristic is obtained.
SELECTOR POSITION FUNCTION
ECVT Selector Position Function:
"D" POSITION. This is the normal cruising position.
Gradual acceleration - When the accelerator pedal is pressed, the vehicle starts from low range. When the engine speed reaches about 1,600 rpm, speed change begins and the vehicle speed rises on the MIN line.
Fast acceleration - The vehicle remains in low range until the engine speed reaches 4,000 rpm and displays maximum acceleration power. When the engine speed exceeds 4,000 rpm, speed change begins gradually and maximum speed is reached on the MAX line while displaying maximum engine output.
From rapid acceleration to cruising - When the pressure on the acceleration pedal is reduced after the desired speed is reached by fast acceleration, the pulley ratio that was on the MAX line shifts to normal cruising on the MIN line. As soon as the engine speed is decreased, the transmission enters overdrive and economy operation begins smoothly.
From cruising to acceleration - When the accelerator pedal is pressed while cruising on the MIN line, the pulley ratio shifts to the low side (MAX line side) automatically and the vehicle speed rises quickly.
"Ds" POSITION. Slope and sporty drive use.
"Ds" Position:
The speed change range in the "Ds" position is limited to the high engine speed zone of the overall speed change range in the "D" position. While running, the engine speed remains above 3,000 rpm (over the "Ds" MIN line) and the engine power and torque can be used to the full. As a result, whereas the "L" position of conventional automatic transmission is limited to the low speed range, the "Ds" position can be used over the entire speed range, from starting to maximum speed, and quick response and a strong engine braking effect are obtained.
"R" POSITION. In the reverse position, the continuously variable speed mechanism is locked in the highest pulley ratio position (low side) and speed change is not performed.
"P" POSITION. In the "P" position, the drive shaft inside the transmission is locked mechanically.
"N" POSITION. In the "N" position, the forward and reverse switching mechanism is placed into the neutral state.
DRIVE POWER PERFORMANCE
ECVT Drive Power Performance Chart:
Since the speed is continuously variable from low speed to high speed, the maximum drive power curve is a single continuous curve, and is different from the maximum drive power curve of conventional transmissions.
The maximum drive power curves for an ECVT and a 3-speed automatic transmission installed in J series model are shown in the figure. This figure shows that the ECVT drive power is superior to that of the 3-speed automatic transmission only in the hatched line region.
In the "Ds" position, the high output range (3,000 rpm and above) of the engine can be used continuously up to high speed by accelerator operation only and the surplus drive power of the ECVT is amply displayed.