Integrated Motor Assist
Encyclopedia
Honda
is a Japanese public multinational corporation primarily known as a manufacturer of automobiles and motorcycles.Honda has been the world's largest motorcycle manufacturer since 1959, as well as the world's largest manufacturer of internal combustion engines measured by volume, producing more than...
's hybrid car technology, introduced in 1999 on the Insight
Honda Insight
The Honda Insight is a hybrid electric vehicle manufactured by Honda and the first production vehicle to feature Honda's Integrated Motor Assist system. The first-generation Insight was produced from 1999 to 2006 as a three-door hatchback...
.
It is a specific implementation of a parallel hybrid. It uses an electric motor
Electric motor
An electric motor converts electrical energy into mechanical energy.Most electric motors operate through the interaction of magnetic fields and current-carrying conductors to generate force...
mounted between the internal combustion engine
Internal combustion engine
The internal combustion engine is an engine in which the combustion of a fuel occurs with an oxidizer in a combustion chamber. In an internal combustion engine, the expansion of the high-temperature and high -pressure gases produced by combustion apply direct force to some component of the engine...
and transmission
Transmission (mechanics)
A machine consists of a power source and a power transmission system, which provides controlled application of the power. Merriam-Webster defines transmission as: an assembly of parts including the speed-changing gears and the propeller shaft by which the power is transmitted from an engine to a...
to act as a starter motor, engine balancer
Balance shaft
In piston engine engineering, a balance shaft is an eccentric weighted shaft which offsets vibrations in engine designs that are not inherently balanced...
, and assist traction motor
Traction motor
Traction motor refers to an electric motor providing the primary rotational torque of a machine, usually for conversion into linear motion ....
. In its first generation, IMA could not power the car on electricity alone, and could only use the motor to assist or start the engine. The 2006 Civic Hybrid
Honda Civic Hybrid
The Civic hybrid, based on the seventh generation Civic, was first introduced to the Japanese market in December 2001. Honda claimed it was the most fuel efficient 5-passenger gasoline-powered production vehicle in the world at the time. It was introduced to the U.S. in spring 2002 as a 2003 model...
, however, can activate the electric motor while the vehicle is coasting without turning the internal combustion engine on, though in contrast to Toyota's Hybrid Synergy Drive
Hybrid Synergy Drive
Hybrid Synergy Drive is a set of hybrid car technologies developed by Toyota and used in the company's Auris, Prius, Highlander Hybrid, Camry Hybrid, Estima, Alphard, Lexus CT, Lexus RX 400h/RX 450h, Lexus GS 450h, Lexus LS 600h/LS 600hL, and Lexus HS 250h automobiles. Toyota also licenses its HSD...
(HSD) or General Motors
General Motors
General Motors Company , commonly known as GM, formerly incorporated as General Motors Corporation, is an American multinational automotive corporation headquartered in Detroit, Michigan and the world's second-largest automaker in 2010...
and DaimlerChrysler
DaimlerChrysler
Daimler AG is a German car corporation. By unit sales, it is the thirteenth-largest car manufacturer and second-largest truck manufacturer in the world. In addition to automobiles, Daimler manufactures buses and provides financial services through its Daimler Financial Services arm...
's Global Hybrid Cooperation
Global Hybrid Cooperation
Global Hybrid Cooperation is a set of hybrid vehicle technologies jointly developed by General Motors, Daimler, and Chrysler LLC, with BMW joining in 2005...
, the IMA has a less powerful motor/generator which allows the car to slow or stop its rate of deceleration to a lesser extent; it cannot operate without turning over the engine which is directly coupled to its electric motor.
The theory behind IMA is to use regenerative braking
Regenerative brake
A regenerative brake is an energy recovery mechanism which slows a vehicle or object down by converting its kinetic energy into another form, which can be either used immediately or stored until needed...
to recapture some of the energy lost through deceleration, and reuse that energy later on to help accelerate the vehicle. This has two effects: it increases the rate of acceleration, and it reduces the work required of the petrol engine
Petrol engine
A petrol engine is an internal combustion engine with spark-ignition, designed to run on petrol and similar volatile fuels....
. The acceleration boost is important as it allows the engine to be scaled down to a smaller but more fuel-efficient variant without rendering the vehicle overly slow or weak. This smaller engine is the primary reason cars equipped with IMA get better highway mileage than their more conventional counterparts.
Additionally, vehicles equipped with IMA can shut off their engine when the vehicle stops and use the electric motor to rapidly spin it back up when the driver releases the brake pedal. They also have a conventional starter as a backup, making it the only production hybrid system which can operate with its high voltage electric system disabled, using only its engine like a traditional vehicle. However, since the IMA also acts as the vehicle's alternator, eventually the 12 volt accessory battery would require an external charge.
Honda powered their Dualnote
Honda Dualnote
The Honda Dualnote is a hybrid sports car concept that was initially unveiled at Japan's Tokyo Motor Show in 2001....
with a 3.5 litres (213.4 cu in) double overhead camshaft (DOHC) i-VTEC
VTEC
VTEC is a valvetrain system developed by Honda to improve the volumetric efficiency of a four-stroke internal combustion engine. The VTEC system uses two camshaft profiles and electronically selects between the profiles. It was invented by Honda R&D engineer Ikuo Kajitani, and was the first system...
V6
V6 engine
A V6 engine is a V engine with six cylinders mounted on the crankcase in two banks of three cylinders, usually set at either a right angle or an acute angle to each other, with all six pistons driving a common crankshaft...
concept engine featuring IMA. Honda claimed the vehicle to produce 400 hp while still being capable of fuel efficiency
Fuel economy in automobiles
Fuel usage in automobiles refers to the fuel efficiency relationship between distance traveled by an automobile and the amount of fuel consumed....
of approximately 18 kilometres per litre (42.3 mpgU.S.).
Other names
- ISG: Integrated Starter Generator
- ISA: Integrated Starter Alternator
- ISAD: Integrated Starter Alternator Damper
- CAS: Combined Alternator Starter
- CSA: Crankshaft Starter Alternator or Combined Starter Alternator
- CISG: Crank-mounted Integrated Starter Generator
List of vehicles using IMA
- Honda J-VXHonda J-VXThe Honda J-VX was the first hybrid sports car concept to employ Honda's Integrated Motor Assist electric hybrid system and was initially unveiled at the Tokyo Motor Show in October, 1997...
(1997 concept car) - Honda InsightHonda InsightThe Honda Insight is a hybrid electric vehicle manufactured by Honda and the first production vehicle to feature Honda's Integrated Motor Assist system. The first-generation Insight was produced from 1999 to 2006 as a three-door hatchback...
(1999-2006, 2010-present) - Honda DualnoteHonda DualnoteThe Honda Dualnote is a hybrid sports car concept that was initially unveiled at Japan's Tokyo Motor Show in 2001....
(2001 concept car) - Honda Civic HybridHonda Civic HybridThe Civic hybrid, based on the seventh generation Civic, was first introduced to the Japanese market in December 2001. Honda claimed it was the most fuel efficient 5-passenger gasoline-powered production vehicle in the world at the time. It was introduced to the U.S. in spring 2002 as a 2003 model...
(2003-present) - Honda Accord Hybrid (2005-2007)
- Honda CR-ZHonda CR-ZThe Honda CR-Z is a compact hybrid electric automobile manufactured by Honda and marketed as a "sport hybrid coupe." The CR-Z combines a hybrid gasoline-electric powertrain with traditional sports car elements...
(2010-present)