Electromagnetic Fuel Injector With Two Independent Coils and Related Control Method

Patent metadata

Field	Value
Publication number	US-2025020096-A1
Application number	US-202418767031-A
Country	US
Kind code	A1
Filing date	Jul 9, 2024
Priority date	Jul 10, 2023
Publication date	Jan 16, 2025
Grant date	—

Abstract

An electromagnetic fuel injector having: a tubular support body; an injection nozzle arranged at an end of the support body; an injection valve coupled to the injection nozzle; a plunger, which is movable, so as to adjust the fuel flow through the injection nozzle, between a closed position and an open position of the injection valve; an electromagnetic actuator provided with a main electromagnet configured, when it is activated, to apply a force to the plunger, which pushes the plunger towards the open position of the injection valve and with a secondary electromagnet configured, when it is activated, to apply a force to the plunger, which pushes the plunger towards the closed position of the injection valve; and a closing spring configured to push the plunger towards the closed position of the injection valve.

First claim

1 ) An electromagnetic fuel injector ( 1 ) comprising:
a tubular support body ( 4 ); an injection nozzle ( 3 ) arranged at an end of the support body ( 4 ); an injection valve ( 7 ) coupled to the injection nozzle ( 3 ); a plunger ( 8 ), which is movable, so as to adjust the fuel flow through the injection nozzle ( 3 ), between a closed position and an open position of the injection valve ( 7 ); an electromagnetic actuator ( 6 ) provided with a main electromagnet ( 11 ) configured, when it is activated, to apply a force to the plunger ( 8 ), which pushes the plunger ( 8 ) towards the open position of the injection valve ( 7 ) and provided with a secondary electromagnet ( 12 ) configured, when it is activated, to apply a force to the plunger ( 8 ), which pushes the plunger ( 8 ) towards the closed position of the injection valve ( 7 ); a closing spring ( 10 ) configured to push the plunger ( 8 ) towards the closed position of the injection valve ( 7 ); and a control unit ( 20 ) configured, so as to open the injection valve ( 7 ), to activate the main electromagnet ( 11 ) so that the main electromagnet ( 11 ) generates a magnetic force moving the plunger ( 8 ) towards the open position, overcoming the elastic force of the closing spring ( 10 ); wherein the control unit ( 20 ) is configured to activate, during the opening of the injection valve ( 7 ) and when the plunger ( 8 ) is close to the open position, also the secondary electromagnet ( 12 ) so that the secondary electromagnet ( 12 ) generates a magnetic force slowing down the movement of the plunger ( 8 ) towards the open position.

2 ) The electromagnetic injector ( 1 ) according to claim 1 , wherein the electromagnetic actuator ( 6 ) comprises one single armature ( 19 ), which is movable, is integral with the plunger ( 8 ) and is shared by both electromagnets ( 11 , 12 ), since it is subjected to the magnetic forces generated by both electromagnets ( 11 , 12 ).

3 ) The electromagnetic injector ( 1 ) according to claim 2 , wherein:
the main electromagnet ( 11 ) comprises a main armature ( 14 ), which is integral with the support body ( 4 ), and a main coil ( 13 ), which is arranged in the area of the main armature ( 14 ); the secondary electromagnet ( 12 ) comprises a secondary armature ( 17 ), which is integral with the support body ( 4 ), and a secondary coil ( 16 ), which is arranged in the area of the secondary armature ( 17 ); and the armature ( 19 ) is arranged between the main armature ( 14 ) and the secondary armature ( 17 ).

4 ) The electromagnetic injector ( 1 ) according to claim 3 , wherein:
the closed position of the injection valve ( 7 ) is determined by a contact of a shutter ( 9 ) of the plunger ( 8 ) against a valve seat of the injection valve ( 7 ); and the open position of the injection valve ( 7 ) is determined by a contact of the movable armature ( 19 ) against the main armature ( 14 ).

5 ) The electromagnetic injector ( 1 ) according to claim 3 , wherein:
the two coils ( 13 , 16 ) of the two electromagnets ( 11 , 12 ) are not connected to each other in series or in parallel; and the control unit ( 20 ) is configured to electrically power the two coils ( 13 , 16 ) of the two electromagnets ( 11 , 12 ) independently of each other.

6 ) The electromagnetic injector ( 1 ) according to claim 3 , wherein the control unit ( 20 ) is configured, so as to open the injection valve ( 7 ), to:
activate the main electromagnet ( 11 ) so that the main electromagnet ( 11 ) generates a magnetic force attracting the armature ( 19 ) towards the main armature ( 14 ), overcoming the elastic force of the closing spring ( 10 ), thus moving the armature ( 19 ) towards the open position; and also activate, when the armature ( 19 ) is close to the open position, the secondary electromagnet ( 12 ), so that the secondary electromagnet ( 12 ) generates a magnetic force attracting the armature ( 19 ) towards the secondary armature ( 17 ), consequently slowing down the movement of the armature ( 19 ) towards the open position.

7 ) The electromagnetic injector ( 1 ) according to claim 6 , wherein the control unit ( 20 ) is configured to deactivate the secondary electromagnet ( 12 ) before the armature ( 19 ) reaches the open position.

8 ) The electromagnetic injector ( 1 ) according to claim 6 , wherein the control unit ( 20 ) is configured, so as to close the injection valve ( 7 ), to:
turn the main electromagnet ( 11 ) off, so that the armature ( 19 ) is pushed towards the closed position by the elastic force generated by the closing spring ( 10 ); and activate, when the armature ( 19 ) is close to the closed position, the main electromagnet ( 11 ), so that the main electromagnet ( 11 ) generates a magnetic force attracting the armature ( 19 ) towards the main armature ( 14 ), consequently slowing down the movement of the armature ( 19 ) towards the closed position.

9 ) The electromagnetic injector ( 1 ) according to claim 8 , wherein the control unit ( 20 ) is configured to deactivate the main electromagnet ( 11 ) before the armature ( 19 ) reaches the closed position.

10 ) The electromagnetic injector ( 1 ) according to claim 1 , wherein the control unit ( 20 ) is configured to deactivate the secondary electromagnet ( 12 ) before the plunger ( 8 ) reaches the open position.

11 ) The electromagnetic injector ( 1 ) according to claim 1 , wherein the control unit ( 20 ) is configured, so as to close the injection valve ( 7 ), to
turn the main electromagnet ( 11 ) off, so that the plunger ( 8 ) is pushed towards the closed position by the elastic force generated by the closing spring ( 10 ); and activate, when the plunger ( 8 ) is close to the closed position, the main electromagnet ( 11 ), so that the main electromagnet ( 11 ) slows down the movement of the plunger ( 8 ) towards the closed position.

12 ) The electromagnetic injector ( 1 ) according to claim 11 , wherein the control unit ( 20 ) is configured to deactivate the main electromagnet ( 11 ) before the plunger ( 8 ) reaches the closed position.

13 ) A control method to control an electromagnetic fuel injector ( 1 ) comprising:
a tubular support body ( 4 ); an injection nozzle ( 3 ) arranged at an end of the support body ( 4 ); an injection valve ( 7 ) coupled to the injection nozzle ( 3 ); a plunger ( 8 ), which is movable, so as to adjust the fuel flow through the injection nozzle ( 3 ), between a closed position and an open position of the injection valve ( 7 ); an electromagnetic actuator ( 6 ) provided with a main electromagnet ( 11 ) configured, when it is activated, to apply a force to the plunger ( 8 ), which pushes the plunger ( 8 ) towards the open position of the injection valve ( 7 ) and provided with a secondary electromagnet ( 12 ) configured, when it is activated, to apply a force to the plunger ( 8 ), which pushes the plunger ( 8 ) towards the closed position of the injection valve ( 7 ); and a closing spring ( 10 ) configured to push the plunger ( 8 ) towards the closed position of the injection valve ( 7 ); the control method, so as to open the injection valve ( 7 ), comprises the steps of: activating the main electromagnet ( 11 ) so that the main electromagnet ( 11 ) generates a magnetic force moving the plunger ( 8 ) towards the open position, overcoming the elastic force of the closing spring ( 10 ); and activating, during the opening of the injection valve ( 7 ) and when the plunger ( 8 ) is close to the open position, also the secondary electromagnet ( 12 ), so that the secondary electromagnet ( 12 ) generates a magnetic force slowing down the movement of the plunger ( 8 ) towards the

Assignees

• Marelli Europe Spa

Inventors

• Signorelli Giorgio
• Petrone Michele
• Petrecchia Stefano
• Mattioli Massimo
• La Malfa Martina
• Zampolli Francesco
• Mundo Nicola
• Mancini Luca

Classifications

• F02M63/0017

  using electromagnetic operating means · CPC title

• F02M61/10

  Other injectors with elongated valve bodies, i.e. of needle-valve type · CPC title

• F02M61/18 Primary

  Injection nozzles, e.g. having valve seats; {Details of valve member seated ends, not otherwise provided for} · CPC title

• F02M63/0056

  Throttling valves, e.g. having variable opening positions throttling the flow · CPC title

• F02M61/20

  Closing valves mechanically, e.g. arrangements of springs or weights {or permanent magnets; Damping of valve lift} · CPC title