Extensible pumping unit for internal combustion engine of motor car, has reducing agent connected to metering valve, work membranes operating expansion material elements, and pressure chamber accommodated in buffer

摘要

The unit (12) has a reducing agent (22) connected to a metering valve (16). Work membranes operate an expansion material element (32), and a pressure chamber (38) is accommodated in a buffer (24). A memory membrane (25) is pre-tensioned by a diaphragm spring (26), where the memory membrane is made of a metal material or plastic material. A pressure sensor (28) is equipped in the buffer, and a throttle element (30) is provided at an outlet side of the reducing agent. An inlet valve is equipped in a suction side of an extension valve.