ELECTRO-TECHNOLOGIES

Below are selected highlights in the development of three candidate electro-technologies, confirming why magnetostrictive transducers are the electro-technology of the future for diesel fuel injection control.   In sum;

• Magnetostrictive alloys offer speed, programmability, and the durability to survive on an engine cylinder head.
  
  
• Piezoelectric ceramics offer speed and programmability, but are susceptible to performance degradation.
  
  
• Solenoids offer durability, but are unsuitable for programming.

In context here, Alexander Graham Bell's invention of the telephone deserves special mention.   Bell leapfrogged intensely creative attempts to use the solenoid-operated telegraph to re-create intelligible speech.   Key features of his telephone included the ability of the earphone diaphragm to quickly and proportionally follow the undulating analog signal input, exactly the same feature required of a programmable diesel fuel injector.

Candidate 1: Magnetostrictive Alloys   Key feature:   mechanical expansion is proportional to current.   Magnetostrictive force and displacement are analogous to thermal expansion except electrically controllable and much, much faster.   Magnetostrictive alloys can be used to reproduce intelligible speech or to rate shape injected fuel, without a durability limit because this quantum mechanical effect is indestructible.

1. 2007.   United States Patent 7,255,290.   Magnetostrictive diesel fuel injector, uses power density capability to raise speed well past the two earlier patents below.   "Very high speed rate shaping fuel injector" increases control over the rate of heat release (fuel economy) and in-cylinder formation of emissions.

• Reduces time at temperature needed for NOx formation through fast (much less than 100 µs to fully open or close) needle lift control.
  
  
• Gets nearer to ideal combustion at constant temperature through infinitely adjustable needle lift control.

2. 2001.   US Patent 6,298,829.   Magnetostrictive natural gas fuel injector, tested in race across desert.
   
   
3. 2001.   US Patent 6,279,842.   Magnetostrictive diesel fuel injector, bench tested.
   
   
4. 1990s-2000s.   Durability, speed, and mechanical power output of terbium alloy established by test.   Mechanical power output, required for speed, can be greater than PZT piezoelectric ceramic without degradation since the effect is inherent and not artificial.
   
   
5. 1960s-1970s.   US Navy develops magnetostrictive alloy of terbium, dysprosium, and iron for ( ( ( sonar ) ) ).
   
   
6. World War II.   Using magnetostrictive nickel transducers, US Navy advances the art of ( ( ( sonar ) ) ) to detect submarines.   Rugged nickel transducers remain in production for industrial process equipment.   (Click on fifth button down on left side, labeled "Transducers.").
   
   
7. 1841.   James Prescott Joule was the first systematic investigator of this proportional growth of iron in a magnetic field, determining that magnetostriction of iron was too small to be a motor.
   
   
8. 1837.   Charles Grafton Page heard galvanic music emanating from iron near a coil.   The music fleetingly appeared at the moment of contact or disconnection of a battery to the coil.

Candidate 2: Piezo-electric Ceramics   Key feature:   mechanical expansion is proportional to voltage.   Piezoelectric force and displacement are analogous to thermal expansion except electrically controllable and much, much faster.   Piezoelectric ceramics can be used to reproduce intelligible speech or to rate shape injected fuel, for a while.   When lightly loaded, they can offer a telegraph-style ON-OFF speed improvement over solenoids, enabling the multiple pulse injections currently being used to reduce diesel emissions.

1. 2000s.   Much publicity heralding piezoelectric diesel fuel injectors as an improvement over solenoid injectors.
   
   
2. 1999.   Degradation of Piezoelectric Materials.   British report describing why it is difficult to apply these materials to a programmable diesel fuel injector.   Specifically, refer to the conclusions on pages 17 and 38 that describe sensitivity to both mechanical cycling and to extended loading.   (Tech note:   "soft" piezoelectric ceramics sacrifice force for more displacement while "hard" ceramics sacrifice displacement for more force.)
   
   
3. 1977.   US Patent 4,022,166.   Piezoelectric fuel injector.
   
   
4. 1970.   US Navy codifies PZT performance degradation in MIL-STD-1376.   In a fuel injector application, PZT degradation is accelerated by higher voltage, stress, strain, and temperature, all of which are present on an internal combustion engine.
   
   
5. Post-WWII.   ( ( ( Sonar ) ) ) power output increased using lead zirconate / lead titanate (PZT) ceramics.   Piezoelectric effect in PZT must be artificially induced as it is not inherent.
   
   
6. World War I.   French physicist Paul Langevin, a student of Pierre Curie, employed quartz to detect another kind of lurking menace, German submarines, then decimating British shipping.   After raiding the available supply of large natural quartz crystals from opticians, Langevin demonstrated the power of ( ( ( sonar ) ) ) in 1917 by killing a lot of fish.
   
   
7. 1912.   When the Titanic struck an iceberg at night and sank, the loss of life strongly motivated the search for ways of using the new electro-technologies to detect submerged objects.
   
   
8. 1880.   Pierre and Jacques Curie discover "pressure electricity."   An electric charge could be made to appear by compressing a piezoelectric crystal, in this case quartz.   The reverse effect of charging a piezoelectric crystal and measuring its displacement was promptly predicted and discovered.

Candidate 3: Solenoids   Key feature:   bang-bang mechanical motion can never be proportional to electrical input and is only suitable for telegraphs and doorbells, not "electronic" fuel injectors.   While durable and reliable, neither intelligible speech nor fuel injector rate shaping can be reproduced by the bang-bang solenoid.

1. 2008.   US Patent 7,334,741.   Late model solenoid fuel injector, well into the piezo era.
   
   
2. 1913.   US Patent 1,059,604.   Early solenoid fuel injector.
   
   
3. 1831.   Joseph Henry discovered the basic principals enabling the telegraph (and doorbell) solenoid   --   strong enough magnetic flux crosses an air gap, causing the two poles to accelerate toward each other until, eventually, they impact each other and bounce back.
   
   
4. 1819.   Hans Christian Ørsted discovers that the needle of a compass is deflected by a nearby electric current.