TRIPLE-VALVE MAXARET ANTI-SKID

Details are given of the new system, called MDR, which has a triple-valve designed specifically for semi-trailers to take account of the differing braking requirements of individual axles in a multi-axle bogie. Braking of all the wheels is kept closer to their adhesion limit using much less air in doing so, meeting the limits set by European legislation. As with most anti-lock systems, a solenoid operated valve shuts off the air supply and exhausts air already in brake chambers when imminent wheel locking is sensed electronically. The microprocessor programming includes a self checking procedure and speed sensors are only needed on the wheels of one axle. However, the three-mode pneumatic valve adds a hold condition to the earlier pressure release and reapply functions. A pair of independently-controlled shut-off valves have been interposed between the basic valve and the brake actuators, each of these valves controlling one or more axles. Pressure can be controlled more finely to individual axles than was the case with just one main valve. Thus, when an uncompensated suspension varies the loading on each axle of a bogie during braking, the MDR system can release the brakes on the potentially locking lighter-loaded axles whilst clamping the pressure and retaining effective braking on the heavier-loaded axle. (TRRL)

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• Corporate Authors:

  Institute of Road Transport Engineeers

  1 Cromwell Place
  London SW1 25F,   England 
• Publication Date: 1984-2

Media Info

• Features: Figures;
• Pagination: p. 34
• Serial:
  • TRANSPORT ENGINEER
  • Publisher: Institute of Road Transport Engineeers
  • ISSN: 0020-3122

Subject/Index Terms

• TRT Terms: Adhesion; Antilock brake systems; Axles; Braking; Electronics; Machine valves; Microprocessors; Numbers; Skid resistance; Tractor trailer combinations; Trailers; Ultimate load design
• Old TRIS Terms: Antiskid device
• ITRD Terms: 5942: Adhesion; 1461: Anti locking device; 1322: Axle; 1874: Braking; 6965: Electronics; 6452: Limit; 8643: Microprocessor; 6432: Number; 1203: Trailer
• Subject Areas: Highways; Motor Carriers; Vehicles and Equipment; I91: Vehicle Design and Safety;

Filing Info

• Accession Number: 00386077
• Record Type: Publication
• Source Agency: Transport Research Laboratory
• Files: ITRD, TRIS
• Created Date: Jul 30 1984 12:00AM