Siemens Automotive Corporation

Siemens-bendix Automotive Electronics Limited

Thomas A Davenport

Gary Michael Everingham

EGR is controlled by a valve whose actuator is a moving electromagnetic coil through which control current representing the desired degree of valve opening is conducted. The coil is disposed in an air gap of a magnetic circuit such that the magnetic flux passes radially through the coil. A coil spring biases the valve closed when there is no current flow through the coil. When control current is conducted through the coil, there is an interaction with the magnetic flux causing the exertion of an electromagnetic force on the coil against the spring force. Relative pressure acting on opposite sides of the valve will assist the coil motion. As a result the coil moves in a direction to increasingly compress the spring until the spring force balances the electromagnetic force. Consequently the valve is opened in an amount proportional to the control current. The motion of the coil is also electromagnetically damped, and a position sensor provides a feedback signal of the valve position.

Engine exhaust gas recirculation (EGR)

A magnetically biased velocity change sensor that is designed for mass-production fabrication and ensuing usage in supplemental inflatable restraint systems of automotive vehicles. The sensor is of the type having a metal sphere that is magnetically biased to one axial end of a tube. When the sensor is subjected to a velocity change of suitable magnitude and duration, the sphere travels to the opposite end of the tube to actuate a switch. Damping of the sphere travel is accomplished by sizing the tube to be of just slightly larger inside diameter than the diameter of the sphere. The invention enhances the manufacturability of the sensor by making dimensioning requirements for the tube and sphere less strict and by enabling different models of sensors to be fabricated from commonly dimensioned tubes and spheres. The invention involves manufacturing the sphere as a sintered iron mass and using a mixture of gases within the tube.

Growing community of inventors

Chatham, Canada

Thomas A Davenport