Device for regulating the idling speed of an internal combustion engine

Claim 2

In a device for regulating the idling speed of an internal combustion engine by varying a flow of fluid fed into the engine, the device including an electromechanical actuator which has electromagnetic means comprising a solenoid incorporating at least one coil; said actuator further comprising ferromagnetic parts conducting magnetic flux, at least one core moveable in response to the flux, and a connecting element driven by movement of the core for adjusting a valve element against a return force; said device further comprising means for maintaining the valve element in a position of a medium rate of air flow upon an interruption in a supply of current to the coil, the improvement wherein said electromechanical actuator comprises two coils responsive to coil currents in opposite directions for acting on the connecting element by imparting a movement to said at least one core, the coil currents being present simultaneously to produce forces in opposite directions, said coils being electromagnetically decoupled to allow said coil currents to be generated independently of each other, a ratio of the magnitudes of the currents establishing the amount of force exerted by magnetic fields of the two coils upon the connecting element and a resultant displacement of the valve element; said device further comprising means for producing the return force, said force producing means being responsive to the coil currents in such a manner that when the coils are without current the valve element is set in a position of medium rate of flow of air, said force producing means including first and a second spring located at opposite ends of said connecting element for counteracting forces induced by said magnetic flux, said force producing means including a third spring means located between said first and said second spring means for isolating said valve element from a pulsation in movement of said connecting element resulting from a pulsation in a coil current.

Claim 3

The device according to claim 1, wherein said connecting element is a push rod and wherein said means which produces the return force acts on said push rod.

Claim 4

The device according to claim 2, wherein said first spring is connected with the valve element on a side thereof opposite the push rod, and said second spring is an adjustment spring which acts in case of a disturbance on the push rod to set a medium rate of flow of air.

Claim 5

The device according to claim 2, wherein in said force producing means said third spring is positioned between one end of said push rod and said valve element, and wherein one of said first and second springs is an opposing spring which acts against said third spring.

Claim 6

The device according to claim 1, further comprising a common return sleeve which is preferably developed symmetrically to a central cross sectional plane of said actuator; and wherein said two coils are arranged in said common return sleeve; there being two cores of ferromagnetic material in alignment with each of said coils, respectively, and wherein said two cores are separated by a gap of low permeability.

Claim 7

The device according to claim 5, wherein said connecting element comprises a push rod made of non-magnetic material, and wherein both of said cores are disposed on said push rod.

Claim 8

The device according to claim 1, further comprising two return sleeves separated by an air gap around a cross sectional plane of said device, there being only one core common to both of said sleeves, which sleeves surround said common core, and wherein a coil is arranged in each of said sleeves.

Claim 9

The device according to claim 5, wherein said connecting element is a push rod; and said push rod is supported in one outer end of each of the two return sleeves.

Claim 10

The device according to claim 2, wherein said device further comprises at least one sleeve enclosing said connecting element, said first and second springs being located one each in outer ends of the return sleeve(s).

Claim 11

The device according to claim 7, wherein said springs are located one each in outer ends of said sleeve(s).

Claim 12

In a device for regulating the idling speed of an internal combustion engine by varying a flow of fluid fed into the engine, the device including an electromechanical actuator which has electromagnetic means comprising a solenoid incorporating at least one coil; said actuator further comprising ferromagnetic parts conducting magnetic flux, at least one core moveable in response to the flux, and a connecting element driven by movement of the core for adjusting a valve element against a return force; said device further comprising means for maintaining the valve element in a position of a medium rate of air flow upon an interruption in a supply of current to the coil, the improvement wherein said electromechanical actuator comprises two coils responsive to coil currents in opposite directions for acting on the connecting element by imparting a movement to said at least one core, the coil currents being present simultaneously to produce forces in opposite directions, a ratio of the magnitudes of the currents establishing the amount of force exerted by magnetic fields of the two coils upon the connecting element and a resultant displacement of the valve element; said device further comprising means for producing the return force, said force producing means being responsive to the coil currents in such a manner that when the coils are without current the valve element is set in a position of medium rate of flow of air, and wherein said ferromagnetic parts are configured for decoupling said coils inductively to permit independent generation of said coil currents free of mutual inductance, said connecting element being free to vibrate in response to pulses of said coil currents, said actuator further comprising means connecting between said connecting element and valve element for decoupling vibrations of said connecting element from said valve element; and wherein said force producing means and said vibration decoupling means include a first and a second spring means, respectively, which are mechanically coupled together at one end of said connecting element.

Claim 13

In a device for regulating the idling speed of an internal combustion engine by varying a flow of fluid fed into the engine, the device including an electromechanical actuator which has electromagnetic means comprising a solenoid incorporating at least one coil; said actuator further comprising ferromagnetic parts conducting magnetic flux, at least one core moveable in response to the flux, and a connecting element driven by movement of the core for adjusting a valve element against a return force; said device further comprising means for maintaining the valve element in a position of a medium rate of air flow upon an interruption in a supply of current to the coil, the improvement wherein said electromechanical actuator comprises two coils responsive to coil currents in opposite directions for acting on the connecting element by imparting a movement to said at least one core, the coil currents being present simultaneously to produce forces in opposite directions, a ratio of the magnitudes of the currents establishing the amount of force exerted by magnetic fields of the two coils upon the connecting element and a resultant displacement of the valve element; said device further comprising means for producing the return force, said force producing means being responsive to the coil currents in such a manner that when the coils are without current the valve element is set in a position of medium rate of flow of air, and wherein said ferromagnetic parts are configured for decoupling said coils inductively to permit independent generation of said coil currents free of mutual inductance, said connecting element being free to vibrate in response to pulses of said coil currents, said actuator further comprising means connecting between said connecting element and valve element for decoupling vibrations of said connecting element from said valve element; and wherein said force producing means and said vibration decoupling means include a first and a second spring means, respectively, which are mechanically coupled together at one end of said connecting element.