The lowly damper (a.k.a. shock absorber) is the unsung hero of any car’s suspension system. Ride and handling specialists sweat untold hours over them, and engineers have painstakingly improved shocks with friction-reducing seals, gas pressurization, electronic valving, and even magnetic fields. While it’s hard to argue with a 3-series BMW’s poise or the comfort strides Ferrari has achieved of late, the damper’s best days may lie ahead. Credit Australian Chris Heyring for inventing a superior means of controlling wheel and body motion and Tenneco for developing that technology into its Kinetic suspension system.
Conventional shocks use calibrated orifices restricting the oil flow through a moving piston to produce damping effects that manage some very complicated, often contradictory forces—wheel impacts (the so-called bump force) want a soft response; body heaves (roll) demand a stiffer one. The Kinetic setup keeps the piston stroking in sync with wheel motion inside an oil-filled cylinder at each corner just as in a conventional shock, but it adds some embellishments. To diminish the usual trade-offs between ride and handling, the creation and manipulation of damping forces are moved outside these hydraulic units in a manner far beyond the electronic valves and remote reservoirs employed before. A network of hoses connects all four units to two hydraulic accumulators (sealed devices containing pressurized nitrogen and oil separated by a membrane). In the most exotic version of the Kinetic system, there’s also a pump to adjust the pressure inside the accumulators.
Heyring’s brainstorm was a scheme for interconnecting the eight chambers inside the four suspension units. The top chambers on one side of the vehicle are hydraulically linked to the opposite side’s bottom chambers, and vice versa [see schematic above].
When a one-wheel bump is encountered, the resulting suspension motion pumps oil into one chamber and out the other side of the piston at that corner of the car. To minimize the disturbance at the other corners, both accumulators regulate this flow. Damping forces are produced as the oil passes through calibrated restrictions (orifices) built into the hydraulic hose attachments.
When the car negotiates a corner, the cross-plumbing arrangement yields a response dramatically different from the one-wheel reaction. Now the outbound flow of oil from all four hydraulic units rushes into just one accumulator. The contained nitrogen acts as a spring to resist that flow. As a result, there’s no need for anti-roll bars or stiff suspension coils to keep the body from listing excessively in a bend.
Because the bump and roll modes act independently, the Kinetic system can be tuned to provide a controlled response over potholes, supple ride motions over dips, and firm resistance to body lean in sweeping bends. Adding electronically adjustable orifices allows the damping to be keyed to car velocity and the driver’s moods. Pumping extra oil into the hydraulic veins raises the accumulator pressure—and roll stiffness—to provide a handy track-day setting.
2011年4月5日星期二
Kaman Awarded $19.8 Million Joint Programmable Fuze Order Raising Program Backlog to $159 Million
Kaman Corporation announced today that its Aerospace segment has been awarded a contract modification in the amount of $19.8 million for the procurement of Joint Programmable Fuzes (JPF). The award is a follow-on order under Option 8 of Kaman's JPF contract with the U.S. Air Force (USAF). Delivery of these fuzes is anticipated to occur in 2013.
"This award raises orders under Option 8 to $43.8 million and total JPF orders since March 2010 to $170 million. Additionally, it secures our JPF backlog of $159 million further into 2013. The JPF is an important program to the U.S. and allied militaries around the world due to the high reliability and operational flexibility that it provides," commented Greg Steiner, President of Kaman Aerospace Group.
Kaman is the sole provider of the JPF, an electro-mechanical bomb safing and arming device, to the USAF and eighteen other nations. The JPF allows the settings of a weapon to be programmed in flight and is the current bomb fuze of choice of the USAF. The JPF is used with a number of weapons including general purpose bombs, and guided bombs that use JDAM or Paveway kits, on U.S. aircraft such as F-15, F-16, F-22, A-10, B-1, B-2, B-52 and the MQ-9 UAV as well as on international aircraft such as Mirage 3 and Gripen. Kaman's regular production schedule is more than 2,000 JPFs per month from facilities in Orlando, Florida and Middletown, Connecticut.
About Kaman Corporation
Kaman Corporation, founded in 1945 by aviation pioneer Charles H. Kaman, and headquartered in Bloomfield, Connecticut conducts business in the aerospace and industrial distribution markets. The company produces and/or markets widely used proprietary aircraft bearings and components; complex metallic and composite aerostructures for commercial, military and general aviation fixed and rotary wing aircraft; aerostructure engineering design analysis and FAA certification services; safe and arm solutions for missile and bomb systems for the U.S. and allied militaries; subcontract helicopter work; and support for the company's SH-2G Super Seasprite maritime helicopters and K-MAX medium-to-heavy lift helicopters. The company is a leading distributor of industrial parts, and operates more than 200 customer service centers and five distribution centers across North America. Kaman offers more than four million items including bearings, mechanical power transmission, electrical, material handling, motion control, fluid power, automation and MRO supplies to customers in virtually every industry. Additionally, Kaman provides engineering, design and support for automation, electrical, linear, hydraulic and pneumatic systems as well as belting and rubber fabrication, customized mechanical services, hose assemblies, repair, fluid analysis and motor management.
"This award raises orders under Option 8 to $43.8 million and total JPF orders since March 2010 to $170 million. Additionally, it secures our JPF backlog of $159 million further into 2013. The JPF is an important program to the U.S. and allied militaries around the world due to the high reliability and operational flexibility that it provides," commented Greg Steiner, President of Kaman Aerospace Group.
Kaman is the sole provider of the JPF, an electro-mechanical bomb safing and arming device, to the USAF and eighteen other nations. The JPF allows the settings of a weapon to be programmed in flight and is the current bomb fuze of choice of the USAF. The JPF is used with a number of weapons including general purpose bombs, and guided bombs that use JDAM or Paveway kits, on U.S. aircraft such as F-15, F-16, F-22, A-10, B-1, B-2, B-52 and the MQ-9 UAV as well as on international aircraft such as Mirage 3 and Gripen. Kaman's regular production schedule is more than 2,000 JPFs per month from facilities in Orlando, Florida and Middletown, Connecticut.
About Kaman Corporation
Kaman Corporation, founded in 1945 by aviation pioneer Charles H. Kaman, and headquartered in Bloomfield, Connecticut conducts business in the aerospace and industrial distribution markets. The company produces and/or markets widely used proprietary aircraft bearings and components; complex metallic and composite aerostructures for commercial, military and general aviation fixed and rotary wing aircraft; aerostructure engineering design analysis and FAA certification services; safe and arm solutions for missile and bomb systems for the U.S. and allied militaries; subcontract helicopter work; and support for the company's SH-2G Super Seasprite maritime helicopters and K-MAX medium-to-heavy lift helicopters. The company is a leading distributor of industrial parts, and operates more than 200 customer service centers and five distribution centers across North America. Kaman offers more than four million items including bearings, mechanical power transmission, electrical, material handling, motion control, fluid power, automation and MRO supplies to customers in virtually every industry. Additionally, Kaman provides engineering, design and support for automation, electrical, linear, hydraulic and pneumatic systems as well as belting and rubber fabrication, customized mechanical services, hose assemblies, repair, fluid analysis and motor management.
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