What's new about Daihatsu "Rocky" and Toyota "Rise"? Developers explain the new 1.2-liter engine and hybrid system

The hybrid system adopts a simple and compact series system

In addition to the 1.0-liter turbo, the new Rocky/Rise powertrain includes a 1.2-liter hybrid and a 1.2-liter naturally aspirated engine. By adopting it, the powertrain lineup has been strengthened to three types. The hybrid model is recommended for users who are looking for environmental friendliness, fuel efficiency, and a sense of innovation. The 1.2-liter naturally aspirated model is recommended for those who mainly ride in the city and place importance on price. , and the power train can be selected according to the usage of each user.

Each engine spec is a 1.2-liter naturally aspirated engine with a maximum output of 64 kW (87 PS) / 6000 rpm and a maximum torque of 113 Nm (11.5 kgfm) / 4500 rpm. 1.2-liter hybrid engine with maximum output of 60kW (82PS)/5600rpm, maximum torque of 105Nm (10.7kgfm)/3200-5200rpm, motor with maximum output of 78kW (106PS)/4372-6329rpm, maximum torque of 170Nm (17.3kgfm)/0- 4372 rpm. The 1.0-liter turbo engine has a maximum output of 72 kW (98 PS) / 6000 rpm and a maximum torque of 140 Nm (14.3 kgfm) / 2400-4000 rpm.

Three powertrains installed in the new Rocky/Rise

The newly developed e-SMART HYBRID combines the "e" of electricity with the word "SMART," which means smart and agile. A series that has strength in the low and medium speed range, which is also a characteristic of the motor, and is an optimal system for small cars with light bodies that are often driven in low and medium speeds. adopted the method. Unlike the series parallel system, which uses the engine for both power generation and driving, and the parallel system such as mild hybrids, which use the motor as an assist, the structure is simple and compact.

In addition, because it is a lightweight Daihatsu vehicle and because it is mainly used for city driving, there was no need to increase the output of the motor so much, so a parallel system using a mechanism such as a planetary gear was used. Compared to the hybrid, it seems that it will be more compact, so we chose the series hybrid system this time.

For this e-SMART HYBRID, Toyota provides motor generators and battery stacks. The basic framework of the PCU (power control unit) is the same, but the control has been developed exclusively for the series system.

The name "e-SMART HYBRID" is derived from the three types of hybrid systems. Among the three types of hybrid systems, the series system, which runs on a 100% motor exclusively for power generation, is adopted.

The engine is a newly developed 3-cylinder 1.2-liter engine optimized for hybrid use. A maximum thermal efficiency of 40% is secured, contributing to improved fuel efficiency. The transaxle has two motors for power generation and drive in parallel. A lightweight and compact design was achieved by minimizing the number of gears.

The battery adopts a lithium-ion battery with high energy density. With a compact capacity of 4.3Ah, it balances performance and cost in order to meet the needs of users who often drive around town. By placing the battery under the rear seat cushion, the hybrid system is achieved while ensuring a spacious interior and cargo space.

Layout image of the hybrid system Newly developed 3-cylinder 1.2-liter engine optimized exclusively for power generation. Specializing in power generation ensures a maximum thermal efficiency of 40%. Two motor generators are arranged in parallel and the number of gears is minimized to achieve compactness. The use of lithium-ion batteries with high energy density reduces weight. contribution. Balancing performance and cost with a compact capacity of 4.3Ah

Mr. Nakayasu said, "We will further evolve the system suitable for small cars, and will quickly expand it to light cars. 100% motor driving. We will internalize the electric drive control by using this technology and connect it to future BEV development.”