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CN-224218201-U - Electromagnetic actuator

CN224218201UCN 224218201 UCN224218201 UCN 224218201UCN-224218201-U

Abstract

The present utility model relates to an electromagnetic actuator. The electromagnetic actuator comprises an electromagnetic field generator, a permanent magnet, an armature, a front magnetic pole and a rear magnetic pole, wherein the front magnetic pole and the rear magnetic pole are respectively positioned at two axial ends of the electromagnetic field generator, the armature is arranged on the radial inner side of the electromagnetic field generator and can be driven by electromagnetic force of the electromagnetic field generator to axially move between a first limit position and a second limit position, the armature is abutted against the front magnetic pole at the first limit position and abutted against the rear magnetic pole at the second limit position, the front magnetic pole and the rear magnetic pole can be magnetized by the permanent magnet respectively to generate magnetic attraction for attracting the armature, and the electromagnetic actuator further comprises a front elastic buffer piece and/or a rear elastic buffer piece. The electromagnetic actuator of the present utility model has an improved structure.

Inventors

  • LIU XIAONA

Assignees

  • 舍弗勒技术股份两合公司

Dates

Publication Date
20260508
Application Date
20250328

Claims (9)

  1. 1. An electromagnetic actuator comprising an electromagnetic field generator, a permanent magnet (40), an armature (50), a front magnetic pole (70 a), a rear magnetic pole (70 b), the electromagnetic field generator and the permanent magnet (40) being coaxially arranged, the front magnetic pole (70 a) and the rear magnetic pole (70 b) being located at the axial ends of the electromagnetic field generator, respectively, the armature (50) being mounted radially inside the electromagnetic field generator and being axially movable relative to the electromagnetic field generator between a first extreme position and a second extreme position by electromagnetic force of the electromagnetic field generator, the armature (50) abutting the front magnetic pole (70 a) in the first extreme position and the rear magnetic pole (70 b) in the second extreme position, the front magnetic pole (70 a) and the rear magnetic pole (70 b) being respectively magnetizable by the permanent magnet (40) to generate a magnetic attraction force that attracts the armature (50), The electromagnetic actuator further comprises a front elastic buffer (80 a) and/or a rear elastic buffer (80 b), the front elastic buffer (80 a) being arranged between the armature (50) and the axial direction of the front magnetic pole (70 a) such that the armature (50) and the front magnetic pole (70 a) axially compress the front elastic buffer (80 a) when the armature (50) is in the first extreme position, the rear elastic buffer (80 b) being arranged between the armature (50) and the axial direction of the rear magnetic pole (70 b) such that the armature (50) and the rear magnetic pole (70 b) axially compress the rear elastic buffer (80 b) when the armature (50) is in the second extreme position.
  2. 2. The electromagnetic actuator of claim 1, wherein the front spring buffer (80 a) is positioned on one of the armature (50) and the front pole (70 a) and/or the rear spring buffer (80 b) is positioned on one of the armature (50) and the rear pole (70 b).
  3. 3. The electromagnetic actuator according to claim 1, characterized in that the front elastic buffer (80 a) and the rear elastic buffer (80 b) are each formed as a wave spring arranged around an axial direction.
  4. 4. The electromagnetic actuator according to claim 3, further comprising a push rod (60), the push rod (60) being fixed radially inside the armature (50) and passing axially through the armature (50), the front elastic buffer (80 a) and the rear elastic buffer (80 b) surrounding radially outside the push rod (60), respectively.
  5. 5. The electromagnetic actuator according to claim 4, characterized in that the push rod (60) radially constrains the front elastic buffer (80 a) and/or the rear elastic buffer (80 b).
  6. 6. The electromagnetic actuator according to claim 4, wherein the front magnetic pole (70 a) includes a front protruding portion (71 a) protruding axially toward the armature (50), the rear magnetic pole (70 b) includes a rear protruding portion (71 b) protruding axially toward the armature (50), the armature (50) includes a front protruding portion (51 a) recessed axially from an axial end face toward the front magnetic pole (70 a) and a rear protruding portion (51 b) recessed axially from an axial end face toward the rear magnetic pole (70 b), the push rod (60) passes through the front protruding portion (51 a) and the rear protruding portion (51 b), respectively, the front elastic buffer member (80 a) is mounted in the front protruding portion (51 a), the rear elastic buffer member (80 b) is mounted in the rear protruding portion (51 b), the front protruding portion (71 a) is inserted into the front protruding portion (51 a) in the first limit position, the front elastic buffer member (80 a) is inserted between the front protruding portion (51 a) and the rear protruding portion (71 b), and the rear elastic buffer member (80 b) is inserted between the front protruding portion and the rear protruding portion (51 b) in the first limit position.
  7. 7. The electromagnetic actuator according to claim 6, characterized in that in the first extreme position the armature (50) abuts the front pole (70 a) by being directed towards an axial end face of the front pole (70 a), and in the second extreme position the armature (50) abuts the rear pole (70 b) by being directed towards an axial end face of the rear pole (70 b).
  8. 8. The electromagnetic actuator according to claim 6, characterized in that the front recess (51 a) radially constrains the front elastic buffer (80 a) and/or the rear recess (51 b) radially constrains the rear elastic buffer (80 b).
  9. 9. The electromagnetic actuator according to any one of claims 1 to 8, characterized in that the range of movement of the armature (50) between the first and second extreme positions is divided into a first end section, which adjoins the first extreme position, a second end section, which adjoins the second extreme position, and an intermediate section, which is connected between the first and second end sections, the front and rear elastic buffers (80 a, 80 b) being uncompressed when the armature (50) is in the intermediate section.

Description

Electromagnetic actuator Technical Field The utility model relates to the technical field of actuators. In particular, the utility model relates to an electromagnetic actuator having a buffer structure. Background An electromagnetic actuator is a component for generating an actuation force. For some applications, the armature of the electromagnetic actuator needs to be held in an extreme position (i.e., in an extended or retracted state) at either end of the interior cavity without energizing, while the switching of the position of the armature is accomplished solely by the electromagnetic force generated upon energizing. This is typically accomplished by generating magnetic attraction forces by magnetizing the front and rear poles with permanent magnets. Such electromagnetic actuators are commonly referred to as bi-stable electromagnetic actuators. For example, with the development of drive-by-wire chassis and electro-mechanical brake (EMB) technology, some current electro-mechanical brake systems employ bistable electromagnetic actuators to achieve a parking lock function. When the vehicle is running normally, the electromagnetic actuator is in a retracted state, and the armature and the rear magnetic pole are kept in abutting contact under the action of magnetic attraction force due to the existence of the permanent magnet. When the armature is propped against the front magnetic pole, the power supply is closed, and the armature and the front magnetic pole are kept propped against each other under the action of the magnetic attraction force due to the existence of the permanent magnet. When the unlocking is needed, reverse current is introduced into the electromagnetic coil, the armature moves towards the rear magnetic pole under the action of reverse electromagnetic force, and after the power supply is turned off, the armature and the rear magnetic pole are kept in abutting connection under the action of magnetic attraction. In the prior art, when such an electromagnetic actuator is switched in state, the armature strikes the front and rear poles, thereby generating significant noise. This has an adverse effect on the user experience of the product. Disclosure of utility model Accordingly, the present utility model has been made to solve the above-mentioned problems occurring in the prior art, and an electromagnetic actuator capable of reducing impact noise is provided. The above technical problem is solved by an electromagnetic actuator according to the present utility model. The electromagnetic actuator comprises an electromagnetic field generator, a permanent magnet, an armature, a front magnetic pole and a rear magnetic pole, wherein the electromagnetic field generator and the permanent magnet are coaxially arranged, the front magnetic pole and the rear magnetic pole are respectively positioned at two axial ends of the electromagnetic field generator, the armature is arranged on the radial inner side of the electromagnetic field generator and can be driven by electromagnetic force of the electromagnetic field generator to axially move relative to the electromagnetic field generator between a first limit position and a second limit position, the armature is abutted against the front magnetic pole at the first limit position and abutted against the rear magnetic pole at the second limit position, the front magnetic pole and the rear magnetic pole can be magnetized by the permanent magnet to generate magnetic attraction force for attracting the armature, and the electromagnetic actuator further comprises a front elastic buffer piece and/or a rear elastic buffer piece, wherein the front elastic buffer piece is arranged between the axial directions of the armature and the front magnetic pole, the front elastic buffer piece is axially compressed, and the rear elastic buffer piece is arranged between the axial directions of the armature and the rear magnetic pole, and the rear elastic buffer piece is axially compressed when the armature is positioned at the second limit position. When the armature moves to abut the front or rear pole, the respective spring buffers disposed therebetween are compressed, thereby generating a spring force against the opposing movement of the two. The impact force of the armature on the magnetic pole can be effectively buffered through the elastic deformation of the two elastic buffer pieces at the abutting moment, so that impact noise is reduced. According to a preferred embodiment of the present utility model, the front elastic buffer may be positioned on one of the armature and the front magnetic pole, and/or the rear elastic buffer may be positioned on one of the armature and the rear magnetic pole. In particular, the elastic buffer can be constrained in the radial direction by an armature or a pole. According to another preferred embodiment of the present utility model, the front elastic cushion and the rear elastic cushion may be formed as wave springs arranged around the