10/7/2003

     Three Yanmar engines in the 19kW<=P<37kW range have been approved under the Tier 2 exhaust emission regulations of the U.S. Environmental Protection Agency due to be enforced on January 1, 2004.
     The engines belong to the TNV Series, which incorporates new technologies and is based on Yanmar’s compact industrial-use TNE Series of diesel engines. The TNV engines have already satisfied the EPA Tier 2, European Tier 2, Japanese special vehicular use and other such regulations.
     These compact industrial engines are supplied to the makers of many work machine types all over the globe, so production and shipment of the TNV series has started in advance of the new regulations.
     Approval for the other TNV series engines is anticipated in due course.

Date of Certification: 12 September, 2003
Certified Engines: 3TNV82A, 3TNV76, 4TNV84T

4TNV

• Reference

The Compact Industrial-use TNV Series of Diesel Engines

     The TNE engine has been one of Yanmar’s main products for the eight years since its release in 1993. The engines are installed on a broad range of work machines, including agricultural, light construction and power generation equipment.
     The just-certified TNV series inherits the C&S (Clean & Silent) concept of the TNE Series. It was developed as an engine that can
satisfy the latest exhaust emission regulations throughout the world.


1. Development Aims
 (1)Satisfaction of all emissions regulations
   •EPA Tier 2 (USA)
   •European Tier 2
   •Japanese special vehicle
   •Construction machinery, etc.
 (2)Satisfaction of the market demand for ultra-quiet operation


2. Engine Features
 (1)Indirect Combustion with Up to 1.2 Liter Cylinder Capacity

1. A bigger cylinder capacity than in the TNE Series gives room to spare in satisfying the emissions regulations and improves reliability, too.


2. Yanmar’s own compact in-line fuel injection pump is used and a strainer is added to the fuel injection valve, raising reliability and making servicing easier, too.


3. Careful analysis has achieved the best structures for the cylinder blocks and other major engine components, the spacing of parts such as the pistons, liners, crankshaft and bearings has been
   adjusted, and gears have been reduced by direct driving of the crank shaft by the lubrication oil pump. The combined result is a roughly 2 to 3 decibel drop in sound compared with the previous engines.

1. The cylinder capacity and external dimensions are the same as for the TNE Series, making replacement easy on existing work machines.


2. The new fuel injection pump retains the in-line reliability, durability and high-performance rotary form, and is fitted with a new timer for precise injection control in response to starting, rpm, load etc.


3. A strainer, micro-suction and double cone valve are used for the fuel injection valve, both reducing emissions and enhancing reliability.


4. Uneven injection of the fuel mist from the different inlets is counteracted by adjusting the angle of attachment of the fuel injection valve, while the new combustion chamber shape, use of high pressure injection for a fine fuel mist, etc., achieve an even fuel mix throughout the chamber, raising efficiency and reducing emissions.


5. The greater noise of high pressure injection is counteracted by the use of stronger engine parts, direct driving of the crankshaft axle by the lubrication oil pump, improvements to the exhaust muffler, etc., keeping noise within the level of the existing series.


6. Four valves (2 inlet, 2 exhaust) are used in engines with a cylinder capacity of over 3.1 liters, achieving both high output and low emissions.