Electromagnetic actuator assembly for a fluid injection valve and method for operating a fluid injection valve

A method for operating a fluid injection valve including a valve needles closing an injection nozzle in a closing position, an armature mechanically coupled to the valve needle, an electromagnetic actuator assembly having a first coil and a second coil configured to move the armature and thereby move the valve needle away from the closing position for dispensing a fluid, and an electrical connection circuit connecting the first and second coils to a power supply, and a first external electrical connection and a second external electrical connection connecting the electrical connection circuit to the power supply, wherein the electrical connection circuit energizes the first coil without energizing the second coil when a direct current flows from the first external connection to the second external connection and energizes both the first coil and the second coil when a direct current flows from the second external electrical connection to the first external electrical connection, the method comprising:

• determining a property of a fluid to be dispensed by the fluid injection valve,
• comparing the determined fluid property with a predetermined threshold,
• based on the results of the comparison, switching an operation of the fluid injection valve between a first operating mode and a second operating mode to generate a magnetic force on the armature and thereby move the valve to dispense the fluid from the fluid injection valve, wherein switching the operating mode comprises:
• when the determined fluid property is smaller than the predetermined threshold according to the comparison, operating the fluid injection valve in the first operating mode by feeding the operating current to the electrical connection circuit via the first and second external electrical connections such that the operating current flows from the first to the second external electrical connection to generate the magnetic force on the armature solely using the first coil, and
• when the determined fluid property is larger than the predetermined threshold according to the comparison, operating the fluid injection valve in the second operating mode by feeding the operating current to the electrical connection circuit via the first and second external electrical connections such that the operating current flows from the second to the first external electrical connection to generate the magnetic force on the armature using both the first coil and the second coil.

A fluid injection valve, comprising:

• an armature;
• a valve needle mechanically coupled to the armature;
• and
• an electromagnetic actuator assembly comprising:
• a first coil and a second coil concentrically mounted in a housing and configured to move the armature to thereby move the valve needle,
• an electrical connection circuit configured to connects the first and second coils to a power supply, and
• a first external electrical connection and a second external electrical connection that are configured to connect the electrical connection circuit to the power supply,
• wherein the actuator assembly is switchable between:
• a first operating mode in which a direct current flows from the first to the second external electrical connection, and
• a second operating mode in which a direct current flows from the second to the first external electrical connection, and
• wherein the electrical connection circuit is configured to:
• energize the first coil without energizing the second coil in the first operating mode of the actuator assembly, and
• energize both the first coil and the second coil in the second operating mode of the actuator assembly.