JSAE Automotive Engineering Exposition 2014: new OEM powertrain technologies

Next-generation Honda NSX, Nissan Skyline hybrid system, Mazda RE range extender

2014/06/11

Summary

JSAE Automotive Engineering Exposition 2014 This report introduces exhibits by Japanese OEMs at the 2014 Automotive Engineering Exposition held in Yokohama, Japan on May 21 to 23, 2014 (hosted by the Society of Automotive Engineers of Japan). This year, a record of 491 companies, including OEMs and parts suppliers, participated in this exposition. The number of visitors also marked a record high of about 88,000, making the exhibition a huge success exceeding the last year.

 Exhibits by OEMs represented their stronger commitment than before. Toyota unveiled a new power semiconductor that helps improve fuel efficiency of  hybrid vehicles (HV). Toyota also exhibited a fuel cell vehicle bare chassis, which had been premiered at the 2013 Tokyo Motor Show.

 Many powertrain technologies including hybrid systems were showcased by OEMs, and attracted considerable attention. Nissan exhibited the hybrid system and steer-by-wire technology that were mounted on the new Skyline. The company also introduced the Smart Rearview Mirror for the first time in Japan, following its global debut at the 2014 Geneva Motor Show. Meanwhile, Honda captured visitors' interests with the next-generation NSX powertrain, which had not been displayed at the Tokyo Motor Show.

 This Part 1 report summarizes these cutting-edge powertrain technologies from OEMs. Part 2 will be posted shortly, to introduce other latest technologies for mini and commercial vehicles as well as safety driving assistance systems. The featured systems include the Smart Rearview Mirror from Nissan and the EyeSight from Fuji Heavy Industries (FHI: maker of Subaru automobiles).

Related Reports: JSAE Automotive Engineering Exposition 2013
  Toyota, Nissan, Honda, and Subaru exhibit new hybrid vehicles and a variety of safety features
  Several EV/HV and start/stop technologies exhibited
  Various equipment and technologies improve fuel efficiency



Hybrid powertrains of next-generation Honda NSX & Nissan Skyline

 

Honda next-generation NSX hybrid system
Next-generation Honda NSX hybrid system

Engine and transmission in the next-generation NSX hybrid system
Engine and transmission in the next-generation NSX hybrid system

Honda

NSX Concept's powertrain Honda exhibited the hybrid system of the NSX super sports car to be launched in North America in 2015. This is an upgraded version of the Sport Hybrid SH-AWD (described below) and drives the front wheels with two motors and the rear wheels with a newly developed longitudinal twin-turbo V6 engine and a dual-clutch transmission (DCT) (the company declined to comment on the engine displacement and the number of gear steps).
Sport Hybrid SH-AWD Honda's three-motor hybrid system for large and midsize passenger cars. The front wheels are driven by a traverse 3.5-liter V6 engine and a 7-speed DCT fitted with one motor, while the rear wheels are driven by two motors. Compared to the NSX, the layout is opposite front to rear and the engine layout also differs between longitudinal and transverse. The system is designed to use the two rear wheel motors (maximum output of 27kW each) at starting and to use the engine during normal driving. As a result, the motor output is smaller than that for the i-MMD two-motor hybrid system (maximum motor output of 124kW), which mainly uses the motors for driving.
The two rear wheel motors generate torque independently. The cornering performance has been improved as the motors can generate a large torque to the outside wheel and a small or negative torque to the inside wheel.
Honda was planning to launch the Acura RLX featuring this Sport Hybrid SH-AWD in the U.S. in spring 2014, but the model has not been released yet as of the end of May 2014. The fuel economy ratings are 28/32/30mpg (city/hwy/combined) in EPA standard.

 

Honda's hybrid systems

i-DCD one-motor hybrid system
i-DCD one-motor hybrid system installed on the Honda Fit/Jazz and other HVs
For details, please refer to the disassembly report.
i-MMD two-motor hybrid system
i-MMD two-motor hybrid system installed on the Honda Accord
For details, please refer to the disassembly report.

 

Nissan

Skyline The 13th-generation Skyline launched in Japan at the end of February 2014 (only hybrid models are available for the time being). The front grille carries the emblem of "Infiniti", instead of "Nissan." Outside Japan, this Skyline was released earlier as the Infiniti Q50. The "Direct Adaptive Steering" steer-by-wire technology is used on the new Skyline for the first time in the world. In Japan, about 5,300 orders have been received in two months after the launch (against the monthly target of 200 units).
On May 26, 2014, Nissan announced the release of a new Skyline model equipped with a 2.0-liter turbo engine in Japan in June 2014. The turbo engine will be supplied from the company's German partner, Daimler.
Hybrid system used on the Skyline The hybrid system used on the 13th-generation Skyline has been upgraded from the one-motor, two-clutch hybrid system used on the Fuga. The hardware has not been changed but the acceleration performance has been improved by 0.4 seconds to 4.9 seconds in 0 to 60 mph acceleration. The fuel economy has also been improved by increasing the time running in EV mode (up 10% in JC08 mode).
In addition, a more precise temperature control has enhanced the maximum motor torque from 270Nm to 290Nm and the maximum (instantaneous) battery output from 60kW to 75kW. Improvements have also been made in the responsiveness and control of the clutch that connects the transmission built-in motor to the engine. An Atkinson cycle is utilized on the engine.
13th-generation Skyline
13th-generation Skyline
Hybrid system used in the Skyline
Hybrid system used on the Skyline

 

 



Toyota displays high-efficiency power semiconductor and FCV bare chassis

 

SiC transistors and SiC diodes
Newly developed SiC transistors (left) and SiC diodes (right)
Scale models of PCUs
Scale models of PCUs that use conventional silicon power semiconductors (left) and SiC power semiconductors (right)

 

High-efficiency power semiconductor Toyota premiered a high-efficiency power semiconductor that uses a new material, SiC (*note), which had been developed in collaboration with Denso and Toyota Central R&D Labs. It is estimated that about 20% of the total electrical power loss in a hybrid model is associated with power semiconductors. Toyota intends to improve fuel economy by improving the efficiency of these power semiconductors.
The company plans to start test driving on public roads within a year. Compared with the current silicon power semiconductor, Toyota aims to improve the hybrid efficiency by 10% and reduce the power control unit (PCU) size to one-fifth in the future.
FCV bare chassis The bare chassis of a sedan-type fuel cell vehicle (FCV) to be launched in 2015. A PCU and a motor are mounted on the front, while a fuel cell and a boost converter are located below the front seat. The chassis was unveiled at the Tokyo Motor Show 2013.
Noah hybrid cutaway Toyota exhibited a cutaway model of the Noah hybrid minivan released in January 2014. A roomy interior has been ensured by using a newly-developed low-floor package. While the overall height was lowered by 25mm from previous models, the cabin height was increased by 60mm higher, thanks to an 85mm lower floor height. The nickel metal hydride battery for driving the hybrid system is located below the front seat to enhance the comfort of the cabin space.
The fuel tank, which is fitted below the floor, was made thinner to lower the floor surface. Thin fuel tanks may cause the fuel pump and gauge not to soak in the fuel when the vehicle tilts, leading to malfunction. To prevent this problem, the fuel pump and gauge are located in a tub with a slit so that the two devices can function properly with the fuel stored in the tub.

Note: Silicon carbide, a compound of silicon and carbon.

 

Toyota FCV bare chassis
Toyota FCV bare chassis


Toyota FCV bare chassis
Front view of the Toyota FCV bare chassis. There are three radiators for cooling the fuel cell, secondary battery, and PCU, respectively. The motor is assumed to be cooled by another method.
Noah hybrid cutaway model
Noah hybrid cutaway model


Noah hybrid fuel tank
Noah hybrid fuel tank, in which the fuel gauge is located at the center and the fuel pump on the right.The upper left of the picture shows the nickel metal hydride battery located under the front seat.

 

 



Mazda: Rotary engine-based range extender

 

Rotary engine-based range extender
Rotary engine-based range extender
Main rotary engine parts
Main rotary engine parts.
The lowers are parts of the 330cc rotary engine developed for the range extender and the uppers are those of the conventional rotary engine.

 

Rotary engine range extender Mazda has developed a power generator (range extender) fitted with a rotary engine, which can be installed on all EVs. A rotary engine is used for the following reasons: 1) Significant noise reduction. 2) Horizontal single-rotor arrangement can reduce the height of the overall system, which can be installed below the rear floor of existing EVs without taking up the cargo space.
The Demio EV equipped with this range extender has increased the EV cruising range from 200km to 380km (in JC08 mode).
The rotary engine has newly been developed and the displacement has been reduced almost by half from the conventional type to 330cc, due to the design for power generation. Mazda has prototyped only one Demio EV equipped with this extender and has yet to decide the future development.
Axela hybrid This third-generation Axela is a hybrid small car developed by fully adopting Mazda's "Soul of Motion" design and "Skyactiv Technology". The model, which was released in November 2013, is built on the Skyactiv -Hybrid system and combines Toyota's hybrid technologies and Mazda's 2.0-liter gasoline engine (Skyactiv-G 2.0) (fuel economy of 30.8km/liter in JC08 mode).

 

Rotary engine extender specifications

Displacement 330cc single-rotor rotary engine
Maximum engine output 22kW at 4500rpm
Generator Maximum rating: 20kW
Fuel tank capacity Approx. 9 liters
Demio EV
Demio EV equipped with the rotary engine extender
The rotary engine extender
The rotary engine extender is located below the rear floor.
Axela hybrid
Axela hybrid

 

 



Mitsubishi Motors' plug-in hybrid system

 

Outlander PHEV
Outlander PHEV
Components in the Outlander PHEV
Components in the Outlander PHEV engine room: Front motor (upper right), generator (lower center), and hydraulic cooling pumps (lower left)

 

Outlander PHEV Outlander's plug-in hybrid EV (PHEV) version launched in Japan in January 2013. The model is based on the "Twin Motor 4WD" system, which uses independent motors for the front and rear wheels. The engine is mainly used for power generation and transmits driving force to the wheels during high-speed driving. The combined fuel economy is 67.0km/liter (in JC08 mode). In May 2014, the interior and exterior were partially redesigned.
Motor and generator system In order to draw attention to Outlander PHEV technologies, Mitsubishi exhibited several systems including the motor and generator on the front wheel part. This front wheel drive motor is cooled by oil, while the rear wheel drive motor is cooled by water, as with the i-MiEV mini EV. Oil cooling was adopted because the system was downsized to be located next to the engine. In addition, the temperature of the engine room becomes very high and extremely hard to cool down by water. The oil also functions as lubricant for the motor bearing.
Drive battery module
Drive battery module mounted on the Outlander PHEV
on-board charger and DC/DC converter
Outlander PHEV's on-board charger and DC/DC converter

 

 



Cutting-edge powertrain technologies from FHI, Suzuki, and Nissan

FHI: Levorg and downsized direct injection turbo engine

Levorg A new sports tourer to be released on June 20, 2014. Two engine types will be available: Horizontally opposed 1.6-liter and 2.0-liter direct injection turbo engines. The advanced driver assistance system, EyeSight (ver.3), will be used for the first time. The new Eyesight improved viewing angle and colored images of the cameras. The release date has been postponed by one month from the original schedule in order to ensure the production quality of EyeSight (ver.3) units.
As of May 2014, FHI has received 12,000 pre-orders. Out of the total, the 1.6-liter model accounts for 70% and the 2.0-liter model for 30%, and 99% will be equipped with the EyeSight.
Horizontally opposed 1.6-liter turbocharged engine A down-sized direct injection turbo engine newly developed for the Levorg. The fuel efficiency is 17.4km/liter, with the maximum output of 125kW and the maximum torque of 250Nm .
In order to improve fuel efficiency, a start-stop system is used for the first time on a FHI turbocharged vehicle. Other new developments include a tumble generator valve (TGV) for enhancing tumble flow and an exhaust gas recirculation (EGR) cooler that can increase the EGR gas amount.
New Levorg
New Levorg
horizontally opposed 1.6-liter turbocharged engine
Newly developed, horizontally opposed 1.6-liter turbocharged engine

Suzuki: 1.2-liter dual jet engine and 5-speed AMT

1.2-liter dual jet engine This engine has been developed to achieve both high fuel economy and pleasant driving without using costly systems such as hybrid, direct injection, and supercharging systems, but by improving thermal efficiency. In July 2013, a grade fitted with this engine was newly added to the Swift compact car (maximum output of 67kW, maximum torque of 118Nm, fuel economy of 26.4km/liter in JC08 mode).
1) Dual jet system: The two injectors per cylinder are fitted on right and left ports, respectively. The two cylinders allows for more flexible injection targets and improves knock suppression and fuel efficiency. 2) Improved combustion: Thermal efficiency has been improved by using a spherical combustion chamber and strengthening the flow in the cylinder. 3) Knock suppression: A water-cooled EGR system is used for the first time by Suzuki. 4) Mechanical loss reduction: Timing chain and pistons have been modified to reduce frictional resistance.
5-speed AMT Auto Gear Shift A new 5-speed MT is mated with an electro-hydraulic actuator that automatically operates clutch and gearshift. The transmission was unveiled at the Delhi Auto Expo held in February 2014. The transmission is already in the Indian market, and mounted on locally produced new Celerio compact cars. The release in Europe is also scheduled.
1.2-liter dual jet engine
1.2-liter dual jet engine
5-speed AMT Auto Gear Shift
5-speed AMT Auto Gear Shift

 

Nissan: Mirror bore coating

A technology that sprays molten iron onto the bore of an aluminum engine cylinder to form a thin layer and mirror-finish it, instead of inserting a cast iron cylinder liner. This technology is effective in reducing weight and improving cooling efficiency as well as in reducing friction with the piston. Nissan plans to apply this technology to engines for mass-market vehicles globally.
Cylinder treated with mirror bore coating
Cylinder treated with mirror bore coating
Cylinder with a conventional iron cast liner inserted
Cylinder with a conventional iron cast liner inserted

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