ELECTROMAGNETIC ACTUATOR HAVING PERMANENT MAGNETS PLACED IN THE FORM OF A V IN AN ELECTROMAGNETICALLY OPTIMIZED ARRANGEMENT

• US 20100271157A1
• Filed: 01/08/2007
• Published: 10/28/2010
• Est. Priority Date: 01/12/2006
• Status: Active Grant

• Current Assignee: Valeo Systemes De Controle Moteur (Valeo SE)
• Original Assignee: Valeo Systemes De Controle Moteur (Valeo SE)
• Inventors: Talon, Emmanuel
• Granted Patent: US 8,169,284 B2
• Time in Patent Office: Days
• US Class Current: 335/229
• CPC Class Codes: F01L 9/20 by electric means
• CPC Class Codes: H01F 7/1646 Armatures or stationary parts of magnetic circuit having permanent magnet

Abstract

The invention relates to an electromagnetic actuator including an actuating member associated with an armature and able to move under the action of at least one electromagnet, a coil, and a core suitable for channeling a flux of the coil so that the flux closes within the armature, where the core includes a base from which branches extend, including a central branch around which the coil extends, and two permanent magnets which are associated with the core. The two permanent magnets are placed in the central branch of the core in order to form a V, which separates the central branch into two parts so that any section of the core or the armature through which the flux from one or the other of the permanent magnets can pass, has an area large enough to prevent saturation by this flux.

Claims

1. An electromagnetic actuator, having an actuating member associated with an armature and capable of moving under the action of at least one electromagnet, comprising:

a coil;

a core designed to channel the flux of the coil so as to form a return path in the armature, the core having a base from which branches extend, including a central branch around which the coil extends; and

two permanent magnets which are associated with the core so that the latter channels the flux of the permanent magnets so as to form a return path in the armature, the flux of the coil passing through the magnets,

wherein the two permanent magnets are placed in the central branch of the core so as to form a V, which separates the central branch into a support part, which supports the permanent magnets and is integral with the base, and an end part lying above the permanent magnets, so that any section of the core or of the armature through which the flux of one or other of the permanent magnets can pass has an area large enough to avoid saturation of said section by this flux.

2. The electromagnetic actuator as claimed in claim 1, wherein each of said sections of the core is shaped so as to have a ratio between an area of a surface for contact with the core of the permanent magnet, the flux of which passes through said section, and an area of said section which is less than or equal to:

3.2 for a core or armature made of silicon-iron;

3.75 for a core or armature made of 17/18% cobalt-iron; and

4.15 for a core or armature made of 48/50% cobalt-iron.

3. The electromagnetic actuator as claimed in claim 2, wherein, for each of said sections, the ratio is greater than or equal to 2.

4. The electromagnetic actuator as claimed in claim 1, wherein at least one of the parts of the core terminates in a point at one end of one of the permanent magnets, the V formed by the permanent magnets having an apex half-angle sufficient to avoid, in said part, saturation of a section taken at an opposite end of said permanent magnet.

5. The electromagnetic actuator as claimed in claim 2, wherein the apex half-angle of the V formed by the permanent magnets is greater than or equal to 10°

.

6. The electromagnetic actuator as claimed in claim 5, wherein the apex half-angle of the V is greater than or equal to:

17°

for a core made of silicon-iron;

13.5°

for a core made of 17/18% cobalt-iron; and

12°

for a core made of 48/50% cobalt-iron.

7. The electromagnetic actuator as claimed in claim 4, in which the apex half-angle of the V formed by the permanent magnets is less than or equal to 25°

.

8. The electromagnetic actuator as claimed in claim 1, in which the V formed by the magnets has a downwardly facing point, the end part having a wedge shape.