Robert Boschgmbh

Walter Schlott

Heinrich Knapp

Klaus-Jurgen Peters

Klaus Riel

Reinhardt Schwartz

There is proposed a pressure regulating valve for a fuel injection system which serves to regulate the heating-up fuel amount for an explosion, external auto-ignition, internal combustion engine. The pressure regulating valve comprises a movable valve component which is urged in the closing direction by a pressure spring which during the heating-up phase acts against a temperature responsive element which in turn acts with a force that can be influenced by another temperature responsive electrically heatable element so that during the heating-up phase the air-fuel mixture can be proportioned in accordance with the requirements of each internal combustion engine.

Pressure regulating valve for fuel injection systems

The control pressure valve assembly for a fuel injection system of an internal combustion engine provides variable fluid pressure which provides a restoring force against the fuel control plunger to alter the fuel-air ratio in dependence on engine and environmental variables. In particular, the fluid pressure is regulated by a spring loaded diaphragm valve which is also subjected to a variable closing force provided by an air pressure cell and by a first temperature sensitive element which opposes the forces of the spring and of the air pressure cell to provide decreased fluid pressure at low engine temperature and a second temperature-sensitive element to oppose the force of the air pressure cell only below a predetermined temperature.

Pressure control valve assembly

A diaphragm-controlled pressure control valve assembly is provided, especially for fuel injection systems in internal combustion engines, in which a measuring member, disposed within the suction tube, is moved by aspirated air against a resetting force. The resetting force is supplied by a pressurized fluid, delivered through a pressure line, which continually acts upon the measuring member. The pressure, which is normally constant, can be arbitrarily changed by pressure control valves. At least one of the pressure-control valves is embodied as a flat-seat valve in which the pre-load of its movable valve member can be changed in dependence on parameters. The movable valve member is constituted by a first diaphragm on whose side pointing away from a fixed valve seat there is disposed a second diaphragm in positive contact with the first diaphragm. The second diaphragm is preferably provided with a relief bore. In a preferred embodiment, two pressure-control valves of similar construction are provided, each including two diaphragms.

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Rommelshausen, Germany

Walter Schlott