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CN-224204990-U - Filter for controlling electromagnetic interference resistance of motor

CN224204990UCN 224204990 UCN224204990 UCN 224204990UCN-224204990-U

Abstract

The utility model discloses a filter for controlling electromagnetic interference resistance of a motor, which belongs to the technical field of filters for controlling electromagnetic interference resistance of motors, and specifically comprises a metal shell, a circuit board and a metal cover plate, wherein the metal shell is provided with a containing cavity, the circuit board is arranged in the containing cavity, five guide pins are arranged at the bottom of the circuit board, wherein four guide pins extend out of the bottom of the metal shell and are isolated from the bottom of the metal shell by adopting glass insulators, the four guide pins are respectively an input positive end, an input negative end, an output positive end and an output negative end, and a fifth guide pin is a grounding end and is fixedly connected to the bottom of the metal shell; after the circuit board is installed in the accommodating cavity, filling is performed by using pouring sealant, and the bottom of the metal shell is connected to a grounding pad on the circuit board. The filter of the utility model realizes the formation of a multistage LC filter circuit in a small enough space, provides high inhibition capability, and simultaneously, the filter is made of metal packaging and can resist interference.

Inventors

  • PAN HUI

Assignees

  • 贵阳顺络迅达电子有限公司

Dates

Publication Date
20260505
Application Date
20250530

Claims (7)

  1. 1. The utility model provides a wave filter for motor control anti-electromagnetic interference, a serial communication port, including metal casing, circuit board and metal cover plate, metal casing is provided with the holding chamber of upper end opening, hold the intracavity and install the circuit components and parts of filter on the circuit board, the circuit board bottom sets up five guide pins, wherein, four guide pins stretch out metal casing bottom and adopt glass insulator to keep apart with metal casing bottom, four guide pins are respectively input positive terminal, input negative terminal, output positive terminal and output negative terminal, the fifth guide pin is the earthing terminal, its fixed connection is in metal casing bottom, the metal cover plate lid closes in metal casing's opening part, adopt the casting glue to fill up after holding the chamber installation circuit board, metal casing bottom is connected to the ground pad on the circuit board through the internal earthing guide pin.
  2. 2. The filter for controlling electromagnetic interference resistance of claim 1, wherein the bottom of the accommodating cavity is provided with a groove, four guide pin fixing seats are arranged at four corners of the groove, a resin plate is arranged at the bottom of the groove, a circuit board supporting step is arranged at the periphery of the bottom of the accommodating cavity, the circuit board supporting step is higher than the guide pin fixing seats, the bottom surface of the circuit board contacts the circuit board supporting step, and four guide pins are arranged on the guide pin fixing seats.
  3. 3. The filter for controlling electromagnetic interference resistance of claim 1, wherein the two ends of the bottom plate of the metal casing are extended outwards to form an extension part, a mounting through hole is arranged in the middle of the extension part, the side wall of the metal casing opposite to the mounting through hole is provided with an inward convex arc structure, and the arc structure is coaxial with the mounting through hole.
  4. 4. The filter for controlling electromagnetic interference resistance of claim 1, wherein the top of the metal housing is provided with an inner sinking step, the metal cover plate is embedded into the step to seal and the top surface of the metal housing is kept flush with the top surface of the metal housing, the bottom of the metal cover plate is provided with a boss, the boss is embedded into the side wall of the metal housing, and the bottom of the boss is provided with an insulating film layer.
  5. 5. The filter for controlling electromagnetic interference resistance of a motor according to claim 4, wherein the top surface and the peripheral side surfaces of the metal cover plate are copper-plated with nickel.
  6. 6. A filter for controlling electromagnetic interference resistance of a motor according to claim 2, wherein the circuit structure of the filter comprises a differential mode inductor L1, a differential mode inductor L2, a common mode inductor L3 and a common mode inductor L4, wherein one input end of the differential mode inductor L1 and one input end of the differential mode inductor L2 are respectively connected with an input positive terminal P and an input negative terminal N, the other end of the differential mode inductor L1 is connected with one input end of the common mode inductor L3 and one end of the capacitor C1, the other end of the differential mode inductor L2 is respectively connected with one input end of the common mode inductor L3 and the other end of the capacitor C1, one output end of the common mode inductor L3 is connected with one input end of the capacitor C2, one end of the capacitor C5 and one input end of the common mode inductor L4, the other end of the capacitor C3 and the other end of the common mode inductor L6 are respectively connected with the ground terminal, one output end of the common mode inductor L4 is connected with one end of the capacitor C4 and the other end of the output positive segment P ', and the common mode inductor L4 is connected with the output end of the positive segment N' of the common mode inductor L4.
  7. 7. A filter for controlling electromagnetic interference resistance of a motor according to claim 6, wherein the common mode inductance L3 and the common mode inductance L4 are symmetrically arranged at the input side and the output side of the circuit board.

Description

Filter for controlling electromagnetic interference resistance of motor Technical Field The utility model relates to a filter for controlling electromagnetic interference resistance of a motor, and belongs to the technical field of filters. Background When the brushless motor is started, the voltage overshoots at the moment of power-on, the magnetic field instantaneously changes to generate very strong current and electromagnetic field, sparks are easy to be caused, in addition, weak contact or friction is often generated and sparks are also good to be generated due to the fact that precision between a rotor and a stator of the brushless motor is insufficient and the magnetic field is repeatedly switched in the running process, when the motor rotates at high speed, conferences are conducted to a motor control system along with a power circuit of the brushless motor, and interference formed by conducting and switching of MOS (metal oxide semiconductor) tubes and diodes of the motor control system is coupled together and conducted out through a power interface of the motor control system, so that normal running of other equipment is interfered. By combining the running characteristics of the brushless motor and the interference conduction path, the electromagnetic interference and frequency multiplication electromagnetic interference of the brushless motor at the rotating speed of up to 20kHz-75kHz are restrained by installing a filter with high restraining capability in front of a power interface of a motor control system, so that the normal operation of other equipment is not influenced, and the problem is thoroughly solved on the conduction path by utilizing the filter. In general, the space of a motor control system module is limited, the space for installing a filter is very limited, and only a filter with the size of 51mmx31mm or smaller can be installed, however, the smaller filter often needs to consider the space utilization rate and the circuit layout, the available suppression capability is poor, the problem cannot be solved only by one filter, two or even three filters with little difference in volume are usually required to be connected in series, and the space required by the motor control system is far exceeded, so that the motor control system cannot be realized. Disclosure of utility model The utility model aims to solve the technical problem of providing a filter for controlling electromagnetic interference resistance of a motor, which provides high inhibition capability, and meanwhile, the filter is manufactured by adopting metal packaging and can resist interference. The utility model adopts the technical scheme that the filter for controlling the electromagnetic interference resistance of the motor comprises a metal shell, a circuit board and a metal cover plate, wherein the metal shell is provided with a containing cavity with an opening at the upper end, the circuit board is arranged in the containing cavity, circuit components of the filter are arranged on the circuit board, five guide pins are arranged at the bottom of the circuit board, wherein the four guide pins extend out of the bottom of the metal shell and are isolated from the bottom of the metal shell by adopting glass insulators, the four guide pins are respectively an input positive end, an input negative end, an output positive end and an output negative end, the fifth guide pin is a grounding end and is fixedly connected to the bottom of the metal shell, the metal cover plate is covered at the opening of the metal shell, the containing cavity is filled with potting adhesive, and the bottom of the metal shell is connected to a grounding pad on the circuit board through an internal grounding guide pin. Further, the bottom of the accommodating cavity is provided with a groove, four guide pin fixing seats are arranged at four corners of the groove, a fully paved resin plate is arranged at the bottom of the groove, a circuit board supporting step is arranged at the periphery of the bottom of the accommodating cavity and is higher than the guide pin fixing seats, the bottom surface of the circuit board contacts the circuit board supporting step, and four guide pins are positioned on the guide pin fixing seats. Further, two ends of the metal shell bottom plate outwards extend to form an extension part, the middle of the extension part is provided with a mounting through hole, the side wall of the metal shell opposite to the mounting through hole is provided with an inward convex arc-shaped structure, and the arc-shaped structure is coaxial with the mounting through hole. Further, the top of the metal shell is provided with an inner sunken step, the metal cover plate is embedded into the step to be sealed, the top surface of the metal cover plate is kept flush with the top surface of the metal shell, the bottom of the metal cover plate is provided with a boss, the boss is embedded into the side wall of the metal shell, and the bot