JSAE Automotive Engineering Exposition 2012: OEMs

Toyota's compact HV system for Prius c; Mitsubishi's PHV system for new Outlander

2012/07/12

Summary

 Reported below is an outline of exhibits by Japanese OEMs at the 2012 Automotive Engineering Exposition held in Yokohama on May 23-25.

 Concerning hybrid vehicles, Toyota exhibited cutaway models of the Aqua (Prius c) compact HV, which enjoys strong sales, and of the Prius PHV. Mitsubishi unveiled a plug-in hybrid EV system that will be used in the Outlander PHEV, which will be launched in 2013. Mitsubishi Fuso showcased a hybrid system that is in combination with a dual clutch transmission; the system is used in the Canter Eco Hybrid, which was remodeled in May 2012.

 Honda exhibited its new engine and CVT for mini vehicles, which are used in the N BOX mini passenger car, while Mazda showcased the New CX-5, of which the diesel model accounted for more than 80% of the sales, and SKYACTIV-D diesel engine. Suzuki unveiled its newly-developed lightweight axle housing while Subaru exhibited a chassis model of the BRZ sports car and a new direct-injection turbo engine.

Related Reports: JSAE Automotive Engineering Exposition 2012: parts suppliers

  EV/HV/PHV and start/stop system technologies
  Technologies for weight reduction, fuel efficiency and safety



Toyota: cutaway models of the Aqua (Prius c) and the Prius PHV


The Aqua's engine room

Under the rear seat of the Aqua
The Aqua's engine room: The engine and the transaxle (left) and the power control unit (right) (Enlarge) Under the rear seat of the Aqua: The gasoline tank in the rear part of the body (on the left of the photo) and the HV battery (upper side), and auxiliary battery (lower side). (Enlarge)

Transaxle of the Aqua

The Aqua's HV battery
Transaxle of the Aqua: The winding wires of the motor and the generator are square for downsizing. (Enlarge) The Aqua's HV battery (Enlarge)

 

Aqua/Prius c  The Aqua is a compact HV launched in Japan in December 2011, which boasts a low fuel consumption of 35.4km/L (JC08 mode). Toyota developed a new compact hybrid system for installation in the Aqua's compact body, which is equivalent to that of the Vitz. The Aqua enjoys strong sales; the accumulated total sales in Japan were 104,000 units by May 2012.
Engine  Toyota upgraded 70% of the components of the 1.5-liter 1NZ-FXE engine, which is used in the second-generation Prius. The engine newly adopts EGR cooler and an electric water pump. The engine radiator is integrated with the inverter radiator to reduce weight
Transaxle  The winding wire of the motor is shifted from round to square and is made 21mm shorter in overall length than that of the third-generation Prius; the weight is reduced by 8kg. Toyota plans to use this technology for downsizing and weight-saving in the next-generation Prius.
HV battery  The HV battery is made 148mm shorter and 11kg lighter than that of the third-generation Prius. The number of modules is reduced from 28 to 20 units and the wiring technique is devised. With this downsizing, the HV battery can be mounted under the rear seat, which helps widen the cargo space.
Prius PHV  The Prius PHV is a plug-in hybrid car of the Prius; which comes with a Li-ion battery that can be recharged from an external power supply. The model was launched in January 2012. The cruising range in EV mode is up to 26.4km. The fuel economy of the plug-in hybrid model is 61km/L (JC08 mode). Compared with the lease model launched earlier, the battery is made lighter and through the improvement of the system, the battery capacity is reduced from 5.2kWh to 4.4 kWh, thereby the vehicle is made lighter and the cargo space larger.

 


A Li-ion battery mounted in the cargo space of the Prius PHV and an on-board charger under the battery.

A Li-ion battery of the Prius PHV
A Li-ion battery mounted in the cargo space of the Prius PHV and an on-board charger under the battery. (Enlarge) A Li-ion battery of the Prius PHV (rear view). Total voltage: 207.2V, total capacity: 4.4 kWh, and number of sells: 56. (Enlarge)

A Li-ion battery of the Prius PHV
A Li-ion battery of the Prius PHV (front view). (Enlarge)

 

 



Mitsubishi plug-in hybrid EV system that will be launched in 2013


Mitsubishi plug-in hybrid EV system

Configuration diagram of Mitsubishi plug-in hybrid EV system
Mitsubishi plug-in hybrid EV system (Enlarge) Configuration diagram of Mitsubishi plug-in hybrid EV system (Enlarge)

 

 Mitsubishi exhibited its plug-in hybrid EV system that it plans to launch in 2013. The engine, one drive motor, and the generator are mounted in the front wheel part and another drive motor in the rear wheel part; the drive battery is mounted under the floor. From an AC outlet in the vehicle, the hybrid EV system can supply electricity that is equivalent to one day's entire energy for an ordinary household. Even when remaining battery charge is not sufficient, the engine generates electricity to supply it.
 The targeted performance (JC08 mode) is an electric range of more than 50km, an entire cruising range of more than 800km, and a combined fuel economy of more than 60km/L. The company will unveil the Outlander PHEV that comes with the system at the Paris Motor Show to be held in September 2012 and is scheduled to start marketing it in Europe in 2013. The following drive modes are available.
EV drive mode  Drive only on the motor. Low-speed, low-load drive including city drive is assumed.
Series drive mode  Drive only on the motor. The engine generates electricity. Acceleration and drive on the mountain road are assumed.
Parallel drive mode  Drive on the motor and the engine. High-speed drive is assumed.
Battery charging mode  While driving, the drive battery is actively recharged. This mode assumes that a good state of charge is secured in order to drive in EV drive mode in the vicinity of the destination.

 


An engine and a motor of Mitsubishi's PHV system

The engine of Mitsubishi's PHV system
An engine (right) and a motor (left) that are mounted in the front wheel part of Mitsubishi's PHV system (Enlarge) The engine of Mitsubishi's PHV system in the middle of the photo (diagonally forward) (Enlarge)

 

 



Mitsubishi Fuso's powertrain of the New Canter Eco Hybrid


A dual-clutch transmission and a motor that are used in the New Canter Eco Hybrid

A 3-liter in-line 4-cylinder diesel engine, the 4P10
A dual-clutch transmission and a motor that are used in the New Canter Eco Hybrid (Enlarge) A 3-liter in-line 4-cylinder diesel engine, the 4P10, which is used in the New Canter Eco Hybrid (Enlarge)

 

Canter Eco Hybrid  The Canter Eco Hybrid is a fully-remodeled hybrid light-duty truck that was launched in May 2012. Daimler group's Global Hybrid Center, which is in Mitsubishi Fuso, developed the model. The fuel economy of the model with a payload in the 2-ton class is 12.8km/L (heavy vehicle mode), which is about 20% better than that of a diesel model in the same class.
 The model adopts the world's first hybrid system (according to Mitsubishi Fuso) that combines a dual-clutch transmission and a motor. The motor is directly connected to the even numbered (outer) gear shaft. The Canter Eco Hybrid can be started and backed only on the motor.
 The model comes with a newly-developed 3-liter in-line 4-cylinder diesel engine, the 4P10. It is jointly developed by Daimler's commercial vehicle division and Fiat Powertrain Technologies.
 The hybrid system adopts a Li-ion battery; the capacity is 7.5 Ah, which is improved by 36% from the former model.

 

 



Honda: lightweight, compact engine and CVT that it uses in the N BOX


New engine for mini vehicles and CVT that Honda uses in the N BOX

Variable valve system for new engines for mini vehicles
New engine for mini vehicles and CVT that Honda uses in the N BOX (Enlarge) Variable valve system for new engines for mini vehicles (Enlarge)

Honda's new CVT for mini vehicles
Honda's new CVT for mini vehicles (Enlarge)

 

New engine for
mini vehicles
 The new engine is a 3-cylinder 660cc engine for mini vehicles, which adopts Honda's next-generation technology - Earth Dreams Technology. The maximum output is 43 kW. The maximum torque is 65Nm. The fuel economy is 22.2km/L (JC08 mode). The weight is reduced by 13% from the former engine; the overall length in the front-rear direction is made 13mm shorter.
Improvement of fuel
economy/output/torque
* Improvement of heat efficiency through DOHC, VTC, and long stroke
* Adoption of hydraulic lash adjuster
* Featuring a start-stop system
* Adoption of drive-by-wire to make coordinated control with CVT possible
Weight-reduction/
downsizing
* By shortening the bore pitch (from 80mm to 76mm), the cylinder block is made thinner
* Adoption of cam chain
* Weight reduction of accessories
New CVT for
mini vehicles
 Since the CVT efficiency is increased when the input torque to the pulley is high and the rotation speed is low, a primary parallel shaft reduction gear is adopted. The parallel shaft gear has a higher reduction gear ratio and can set the optimal ratio for both the naturally-aspirated engine and turbo engine. The pulley is also more freely positioned.
Weight-reduction/
downsizing
* The pulley is positioned higher and the control system of the CVT is mounted under the pulley, thus the overall length in the front-rear direction is made shorter.
* Transmission case is made into two-piece structure in order to reduce weight.
* Parking gear is forged on the back of the pulley.

 

 



Suzuki: Engine used in the Alto Eco and a single-piece lightweight axle housing


An upgraded R06A engine that is used in the Suzuki Alto Eco
An upgraded R06A engine that is used in the Suzuki Alto Eco
(Enlarge)

 

Upgraded
R06A engine
 The upgraded R06A engine is a 3-cylinder 660cc engine that is used in the Alto eco, which was launched in November 2011. In order to improve the fuel economy of vehicles with CVT, the high efficiency area is expanded through a low to high load in low rotation speed. The friction of the cam shaft, crank shaft, and oil pump is reduced.
Lightweight
axle housing
(under development)
 Suzuki is currently developing a single-piece lightweight axle housing that is made of one steel pipe. Currently, seven parts are welded, but a new hydroforming method is applied. By forming it from one part, welded parts are eliminated; while the axle housing maintains similar strength with a 10% weight reduction. Suzuki's next challenge is to develop the technology for volume-production (jointly develops with Nippon Steel).
Current
hydroforming method
 The current hydroforming method is a method in which water is run through a steel pipe in the die; the water pressure is increased to press the steel pipe to the die to form the axle housing. Compared to the original steel pipe, the circumferential length of the inflated part is made up to 1.2-fold longer.
New hydroforming method  The new hydroforming method is a method in which a special movable die is used; the mold process is separated into three processes, which makes it possible to make the circumferential length of the original steel pipe up to 3-times longer. By adjusting the thickness of the inflated part of the steel pipe in the movable die, a longer circumferential length is achieved. Among the three processes, the circumferential length is made 2.4-times longer in the first process.

 


Single-piece light-weight axle housing that is molded using a new hydroforming method

Presentation panel for light-weight axle housing
Single-piece lightweight axle housing that is molded using a new hydroforming method (Enlarge) Presentation panel for lightweight axle housing (Enlarge)

 

 



Mazda: CX-5, which enjoys strong sales, and SKYACTIV-D clean diesel engine


Mazda's New CX-5, which enjoys strong sales

SKYACTIV-D 2.2 engine
Mazda's New CX-5, which enjoys strong sales SKYACTIV-D 2.2 engine: 2-stage turbo charger and cooled EGR (Enlarge)

Electric double layer capacitor of the i-Eloop
Electric double layer capacitor of the i-Eloop, which is Mazda's regenerative braking system (Enlarge)

 

CX-5  The CX-5 is a crossover SUV that Mazda launched in February 2012. The model has adopted Mazda's entire SKYACTIV technology. The accumulated total number of orders in Japan is about 23,000 units during the first four months after its launch, which are about twice the planned annual sales volume. The model with SKYACTIV-D 2.2 clean-diesel engine accounts for about 80% of the sales.
SKYACTIV-D  The SKYACTIV-D is a clean-diesel engine that has achieved the low-compression ratio of 14.0 and a weight reduction. The engine meets emission standards in Japan, the US, and Europe without an after-treatment system. It was used in the CX-5 for the first time. It will also be used in the New Atenza (scheduled to be launched in the second half of 2012), which is based on the concept car TAKERI. "Combustion timing" and "mechanical resistance" are mainly improved.
Reduction of
resistance
 The entire resistance of the engine is reduced by about 20% (from that of the current engine) through the improvement of the water-flow resistance of the head block, and of the vacuum pump, crank shaft, piston, piston ring, connecting rod, and the variable oil pump.
Weight saving  By reducing the compression ratio to 14.0, the engine block is made of aluminum and the weight of the piston and connecting rod is reduced. The entire weight of the engine is reduced by 10% of the current engine.
2-stage
turbo charger
 Improvement of low-speed, high-speed torque, reduction of soot.
Cooled EGR  Reduction of NOx
Exhaust VVL
(Variable Valve
Lift Mechanism)
 Improvement of combustion stability in a cold start.
i-ELOOP  The i-ELOOP is a regenerative braking system that is made up of a variable-voltage generator, an electric double layer capacitor, and a DC/DC converter. In order to regenerate braking energy efficiently, a variable-voltage generator (maximum voltage: 25V) is used for power generation. It takes only a few seconds to fully charge the capacitor and the charged electricity can be consumed in about one minute. Therefore, frequent charging is possible, and it is expected to improve fuel efficiency by up to 10% in city driving. Mazda plans to use the i-ELOOP in the New Atenza.

 

 



Subaru: a chassis model of the BRZ and a new 2.0-liter boxer direct-injection turbo engine


BRZ's engine and front wheels

BRX's engine and transmission
BRZ's engine and front wheels (Enlarge) BRZ's engine and transmission (Enlarge)

Subaru's 2.0-liter boxer direct-injection turbo engine
Subaru's 2.0-liter boxer direct-injection turbo engine (Enlarge)

 

FR chassis model  The FR chassis model is a skeleton model of the powertrain/suspension of the BRZ/86 FR sports car, which is jointly developed with Toyota. The engine is mounted as low as possible to achieve a centre of gravity height of 460mm (measured by Subaru).
2.0-liter boxer
direct-injection
turbo engine
 This is a direct-injection turbo engine in the new horizontally-opposed engine series that Subaru put onto the market in 2011. The engine is available with the Legacy, which underwent a facelift in May 2012. It adopts a twin scroll turbo. The maximum output is 221kW/5600rpm; the maximum torque is 400Nm/2000-4800rpm. The 1.6-liter direct-injection turbo engine that was unveiled at the Tokyo Motor Show is currently being developed.

<Automotive Industry Portal MarkLines>