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Deep Dive Into Denso

Japanese auto parts supplier focuses on environmentally-friendly technology.

In 1949 Nippondenso Co. Ltd. was spun off from Toyota Motor Co. Ltd. with a modest capital base of ¥15 million, something less than $150,000 at today’s exchange rate. In late October of this year, the company now known as Denso Corporation was projecting record sales of $22 billion for its fiscal year ending in March 2004, putting it comfortably among the top five OE automotive suppliers in the world.

Denso growth very much parallels Toyota’s success. In the years from 1988 to 2000, Denso total sales actually doubled. Though separated from Toyota more than 50 years ago, nearly 50 percent of Denso’s sales are still accounted for by Toyota.

Conversely, however, that means some $11 billion in sales is to other automakers and engine builders of the world, and Denso is certainly out to win more. It consistently wins accolades from its customers. General Motors, for example, has named Denso supplier of the year for 10 consecutive years.

The chart above shows the regeneration of the Diesel Particulate Filter.
Denso’s engine products are its largest product sector, representing 37 percent of its business, with climate control at 30 percent, computer related products at 14 percent, with information and communication systems, instruments and small motors accounting for the balance. Information Technology Systems (ITS) are expected to be the largest area of growth in years ahead. The use of pre-crash safety systems and adaptive front lighting systems are also evolving rapidly.

Japan accounts for 57 percent of Denso’s sales volume, the Americas for 23 percent, Europe for 12 percent, with the balance going to Asia, Oceania, and other lands.

Following the 2003 Tokyo Motor Show, I joined with several other journalists for an extensive tour of Denso’s R&D center, several engineering and production facilities, and to interview key executives and engineering managers about Denso developments and directions.

Our deep dive into Denso revealed a richly textured organization of 90,000 employees all seemingly moving in the same direction to produce world class quality products at lowest cost with the least possible environmental impact.

In the lab, piezo-based injectors  have reached pilot injection intervals of 0.1 milliseconds.
“Denso considers environmental protection in all of its activities,” said Koichi Fukaya, president and CEO, “including planning, development design, manufacturing, marketing and services. We are developing technologies that will reduce the environmental burden of vehicles.

“We’re also tackling higher fuel efficiency, exhaust gas purification and automotive air conditioning systems that have minimal impact on global warming.”

Denso’s immediate strategy is to maintain its global leadership position in automotive air conditioning, achieve the leadership position in engine and powertrain products and to further develop its ITS and telematics products, prominently including navigation systems. According to Hiroshi Uchiyama, senior managing director of Denso, the company is very focused on making ITS the third pillar of Denso’s product portfolio.

Denso’s efforts are backed by a strong commitment to research and development. The company R&D budget is typically in the range of 8 percent of net sales. The development work is organized into three areas: safety, environment and information—matching up generally with the three product areas.

Specific product development, however, is separate from pure R&D and is also budgeted separately. Some 70 percent of the corporate R&D would be classified as basic research in fields such as materials technology, semiconductors, nano technology, telecommunications, energy conversion and biotechnology.

While most of this activity supports Denso’s automotive related product, the company indicates it will push into new fields if that’s where its research takes it. Denso already does some business in factory automation, luminescent displays, bar code scanners, heat pumps, residential and office air conditioning. And while the company is committed to growing these businesses, automotive systems remain at the base of its core competency.

Denso automotive developments are both frequent and far ranging. This year it introduced a novel new fuel pump, called the model GH, which is half the size of a conventional fuel pump and uses 25 percent less power. It is driven by a very compact DC motor with a high density winding. A highly optimized impeller on the pump helps achieve smooth fuel flow and efficiency.

On the diesel side, Denso has recently introduced an 1800 bar common rail system, which meets EURO4 emission regulations without a particulate filter. It is widely applied in Europe by Mazda, Toyota, and Nissan. Ford will adopt the new system in 2005. The system is currently being manufactured in Hungary and will also go into production in Thailand next year.

Denso claims to be the first fuel injection manufacturer to go into production with a common rail diesel injection system. That was in 1995. And this new system is currently the only one in production at the 1800 bar range. A 2000 bar system is being developed and it will use piezo electric technology. That should see production in 2005.

The 1800 bar system makes splitting a second like pealing an onion. Injectors can inject fuel in 0.4 milliseconds intervals as precisely as one cubic millimeter per injection. Five multiple injections can be made each combustion stroke, and it may go to seven in the future, one engineer told me.

The system also uses a software compensation method that compensates each injector individually for its manufacturing variance. Each injector has a two dimensional code that is read by the engine ECU and the system automatically compensates each injector by 0.5 cubic millimeters or less during injection. Compared with Denso’s conventional system, the new system increases engine output by approximately 24 percent, engine torque by 35 percent and cut low idle noise by 6.5 db(A) on a 2.0 liter diesel, according to Denso. On the piezo based injectors, the company has experimentally confirmed pilot injection intervals of 0.1 milliseconds with improved rate characteristics with still lower emissions and noise.

The CO2 air-conditioning system on the Toyota FCHV has refrigerant pressures between 9-12 MPa on the high side and 3.5-4.5 MPa on the low pressure side under normal thermal load.
Another new product in the diesel area is a diesel particulate filter (DPF). This traps particulate matter (PM) and causes the system catalyst to burn the PM. Unburned fuel and exhaust gas react with the catalyst and raise temperature (over 600 oC) to burn the PM. The DPF is made of a cordierite ceramic which lowers the material costs and is also easy to manufacture.

Sensors in the system measure the pressure and temperature drop before and after the DPF to determine the amount of PM accumulated and then control the DPF temperature accordingly.

As a key supplier to Toyota, Denso is deeply involved in such high profile vehicles as the new Prius and Toyota’s fuel cell hybrid vehicle (FCHV). For the Prius it developed a novel scroll type compressor with an integral DC brushless motor and inverter.

Since the heat engine in the Prius is turned off at various points in the operating cycle, the air conditioning compressor had to be electric drive and not mechanical.

Denso’s compressor is said to be 40 percent smaller and 50 percent lighter than a conventional electric compressor. This was achieved with highly optimized structures and control methods for the motor and inverter. Even more exciting, however, is the new CO2 air conditioning system the Denso supplies on Toyota’s FCHV, a world first. Everyone in the automotive HVAC field is working on such systems, but this one is in operation.

Air conditioning systems using CO2 as refrigerant are the odds on favorite to replace hydrofluorocarbon 134a (HFC-134a) systems and lessen the impact of AC on global warming. CO2 has a global warming potential that is 1/1300th of HFC-134a and while it,s not the only possibility, it does seem to have the strongest case.

The CO2 cycle can as readily be applied as a combination air conditioner and heat pump, which can be important when there is no internal combustion engine to supply heat. Even modern small diesels do not supply an adequate heat source so CO2 is looking very attractive at the moment. CO2 systems perform dehumidification as well.

The so called Coefficient of Performance (COP) of CO2 systems is somewhat lower than HFC-134a systems, but not significant. And system pressure is considerably higher (7 to 10 times) than for HFC-134a and will required heavier gauge tubing and better fittings and connections, but still manageable.

Denso’s system on the Toyota FCHV has refrigerant pressures between 9-12 MPa on the high side and 3.5-4.5 MPa on the low pressure side under normal thermal load. Pressure varies, of course, with the operating cycle of the system. The compressor for the system is driven by a powerful 3.5 kW DC electric motor that is integral with the compressor. The compressor displacement is a mere 3.8 cc in displacement, about 1/6th the size of a comparable HFC-134a compressor.

Denso sees rapid growth in the crash-avoidance electronics.
Denso claims to be the market leader in automotive air conditioning and is doing all it can to increase market penetration. Taking a leadership role in CO2 cycle systems underscores its dedication.

Actually, Denso claims top market share for 18 different automotive products and one nonautomotive product—that being small industrial robots for loads less than 20 kg. Automotive products run the gamut from starters and alternators to variable camshaft timing components and high intensity discharge lamps (see Table). It has marked out other target areas for holding the number one position.

Boiling Denso down to a simple mission statement, Koichi Fukaya stated, “providing new values far beyond the expectations of customers and society.” That says it well.

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