Device for improving electro magnetic compatibility (EMC) performance of non-metal universal terminal of servo driver

Abstract

The utility model provides a device for improving the EMC performance of a non-metal universal terminal of a servo driver, a shielding box body comprises a cover body and a bottom plate, the cover body and the bottom plate are spliced to form a relatively closed shielding chamber, the top end face of the cover body is provided with a first through hole, a first interface terminal passes through the first through hole, and a second interface terminal passes through the second through hole. One end of the second interface terminal is electrically connected with the first end face of the circuit board, the other end of the second interface terminal is electrically connected with an external cable, a second through hole is formed in the end face of the bottom plate, the second interface terminal penetrates through the second through hole, one end of the second interface terminal is electrically connected with the second end face of the circuit board, and the other end of the second interface terminal is electrically connected with a universal terminal of the servo driver; the shielding box body is used for conducting the first interface terminal and the second interface terminal, and the outer edge of the bottom end face of the shielding box body is further provided with a surrounding closed shielding gasket used for improving the sealing effect between the shielding box body and the connecting face of the servo driver. According to the utility model, the electromagnetic compatibility of the non-metal universal terminal of the servo driver can be effectively improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of electromagnetic compatibility, and in particular relates to a device for improving the EMC performance of a non-metallic universal terminal of a servo driver. Background Art

[0002] During the operation of the servo drive, the voltage and current flowing through the internal circuit and various components will change. In particular, when the drive performs switching operations or the load changes, these current and voltage changes will generate corresponding electromagnetic fields, thereby generating electromagnetic interference. At the same time, parasitic capacitance may exist between the circuits and components of the servo drive. The parasitic capacitance will cause electromagnetic coupling, allowing the electromagnetic interference to propagate and amplify. The shells of existing servo drives often adopt special designs to achieve electromagnetic shielding effects, but the universal terminals directly connected to external devices are often made of non-metallic materials, resulting in insufficient electromagnetic shielding functions of the universal terminals, causing the electromagnetic waves of the servo drive to leak outward through the external cables of the universal terminals, thereby causing electromagnetic interference to external devices. At the same time, the electromagnetic radiation overflowed from the external device can also leak into the external space through the interface of the universal terminal, or interfere with the normal operation of the servo drive.

[0003] At present, the market is increasingly strict with the CE mark certification of electrical products. For example, before the release of servo drive products, EMC electromagnetic compatibility testing must be completed. Electromagnetic compatibility testing is a comprehensive assessment of the interference size (EMI) and anti-interference ability (EMS) of electronic products in the electromagnetic field. It is one of the important indicators of product quality. It can effectively measure whether electrical or electronic products can withstand possible electromagnetic interference in the external space and will not generate electromagnetic interference to the external space, thereby avoiding affecting the correct operation of other electrical products.

[0004] Under the existing technology, in order to improve the electromagnetic compatibility performance of the universal terminal of the servo drive, if the structure of the non-metallic universal terminal of the servo drive is improved, since the universal terminal of the drive needs to be connected to the cables of different devices, changing the structure of a single universal terminal requires synchronous changes of multiple connection devices of different brands and manufacturers, which is difficult to implement and costly. If the internal circuit of the servo drive is optimized to reduce the overall electromagnetic interference of the servo drive and improve the overall electromagnetic anti-interference ability of the servo drive, the overall R&D time cycle is long, the R&D difficulty is high, and the investment cost is high, which greatly increases the production cost of the enterprise. Utility Model Content

[0005] The utility model aims to provide a device for improving the EMC performance of a non-metallic universal terminal of a servo drive, so as to solve the technical problems that the non-metallic universal terminal of the existing servo drive is prone to electromagnetic wave leakage and has weak electromagnetic wave shielding performance for external space.

[0006] To solve the above problems, the technical solution of the utility model is: a device for improving the EMC performance of non-metallic universal terminals of servo drives, comprising: a shielding box body made of metal material, a first interface terminal, a second interface terminal and a circuit board;

[0007] The shielding box body is wrapped and covered on one side of the electrical connection end surface of the servo drive universal terminal, and is used to improve the electromagnetic compatibility of the servo drive universal terminal. The shielding box body includes a cover body and a bottom plate, and the cover body and the bottom plate are spliced ​​and fixed to form a relatively closed shielding chamber, and the circuit board is arranged in the shielding chamber;

[0008] A first through hole is provided on the top end surface of the cover body, the first interface terminal is passed through the first through hole, and the second end of the first interface terminal is electrically connected to the first end surface of the circuit board, and the first end of the first interface terminal is used to be electrically connected to an external cable; a second through hole is provided on the end surface of the bottom plate, the second interface terminal is passed through the second through hole, and the first end of the second interface terminal is electrically connected to the second end surface of the circuit board, and the second end of the second interface terminal is used to be electrically connected to the universal terminal of the servo drive; the first end surface and the second end surface of the circuit board are respectively engraved with circuits that conduct from the first end surface to the second end surface, and the circuit board is used to conduct the first interface terminal and the second interface terminal, thereby achieving electrical connection between the external cable and the universal terminal of the servo drive;

[0009] A surrounding and closed shielding gasket is also provided on the outer edge of the bottom end surface of the shielding box body that fits the servo driver. The shielding gasket is used to improve the sealing effect between the connecting surface of the shielding box body and the servo driver.

[0010] Preferably, the shielding box body is made of electrolytic galvanized steel material.

[0011] Preferably, the housing of the first interface terminal is made of metal material, and the housing of the second interface terminal is made of non-metal material.

[0012] Preferably, the first interface terminal is a DSUB-25 connector.

[0013] Preferably, the shielding pad is made of conductive foam material.

[0014] Preferably, the thickness of the shielding gasket is limited to be slightly larger than the distance between the bottom end surface of the shielding box body and the opposite end surface of the servo driver.

[0015] Preferably, an extending mounting plate is provided laterally at the bottom of the shielding box body, the mounting plate is attached to the end face of the servo driver, a first fixing hole is opened in the mounting plate, a screw is passed through the first fixing hole and is threadedly connected to the servo driver for fixing and installing the shielding box body.

[0016] Preferably, a second fixing hole is opened in the bottom plate, and a screw is passed through the second fixing hole and is threadedly connected to the cover body to fix the cover body and the bottom plate.

[0017] Preferably, the first through hole and the second through hole are asymmetrically designed in the vertical direction of the shielding box body, so as to be used for staggered arrangement of the first interface terminal and the second interface terminal.

[0018] Preferably, the first interface terminal and the second interface terminal are fixedly connected to the conducting circuits of the first end surface and the second end surface of the circuit board respectively by welding.

[0019] Due to the adoption of the above technical solution, the utility model has the following advantages and positive effects compared with the prior art:

[0020] (1) The utility model provides a device for improving the EMC performance of a non-metallic universal terminal of a servo drive. The device is in the form of a box structure as a whole, and a first interface terminal and a second interface terminal are arranged inside the device. The first interface terminal and the second interface terminal are electrically connected at opposite ends in the shielding box through a circuit board. The other end of the first interface terminal can be electrically connected to an external cable, and the other end of the second interface terminal can be electrically connected to a universal terminal of the servo drive. That is, on the premise that the universal terminal of the servo drive can be normally connected to the cable of an external device, the electrical connection end surface of the universal terminal of the servo drive is externally wrapped and covered with a shielding box. The shielding box is made of metal material to form a Faraday cage structure, which can shield the electromagnetic radiation leaked from the universal terminal of the servo drive. At the same time, it can also prevent the electromagnetic radiation leaked from the external device from having an adverse effect on the servo drive through the universal terminal.

[0021] (2) In a device for improving the EMC performance of a non-metallic universal terminal of a servo drive provided by the utility model, a surrounding and closed shielding pad is provided on the outer edge of the bottom end surface where the shielding box body and the servo drive are in contact. The shielding pad is made of a conductive foam material. The conductive foam material has a certain elasticity and is used to fill the gap between the connecting surface of the shielding box body and the servo drive, so that the outer edges of the connecting surfaces of the two are more closely fitted. The interaction effect between the internal conductive fiber and the external metal shielding material is utilized to realize the absorption of internal electromagnetic waves and the shielding function of external electromagnetic waves, thereby further improving the electromagnetic compatibility performance of the utility model. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A schematic diagram of a cross-sectional connection structure of a device for improving the EMC performance of a non-metallic universal terminal of a servo drive provided by the utility model;

[0023] Figure 2 The utility model provides a three-dimensional structural schematic diagram of a device for improving the EMC performance of a non-metallic universal terminal of a servo drive.

[0024] Explanation of the reference numerals: 1: shielding box body; 2: first interface terminal; 3: second interface terminal; 4: circuit board; 5: shielding pad; 6: servo drive universal terminal; 7: servo drive; 8: cable. DETAILED DESCRIPTION

[0025] The following is a further detailed description of a device for improving the EMC performance of a non-metallic universal terminal of a servo drive proposed by the present invention in conjunction with the accompanying drawings and specific embodiments. The advantages and features of the present invention will become more apparent from the following description and claims.

[0026] See also Figure 1 to Figure 2 , this embodiment provides a device for improving the EMC performance of non-metallic universal terminals of servo drives, including a shielding box body 1 made of metal material, a first interface terminal 2, a second interface terminal 3 and a circuit board 4. Among them, the shielding box body 1 is wrapped and covered on one side of the electrical connection end face of the servo drive universal terminal 6, and the shielding box body 1 is in contact with the end face of the servo drive 7. Since the servo drive 7 generates certain electromagnetic radiation during operation, in this embodiment, the servo drive universal terminal 6 is made of non-metallic material, and the electromagnetic radiation will leak through the non-metallic universal terminal with insufficient electromagnetic shielding function, which is easy to cause electromagnetic interference to other devices. At the same time, other devices will also generate electromagnetic radiation, which will leak to the external space at the universal terminal interface, causing RE radiation to exceed the standard, or further leak to the inside of the servo drive 7 through the servo drive universal terminal 6, affecting the normal operation of the servo drive 7 itself, so the shielding box body 1 is provided to improve the electromagnetic compatibility performance of the servo drive universal terminal 6.

[0027] Specifically, the shielding box body 1 includes a cover body and a bottom plate. The cover body is a box-shaped structure with only one side open. The bottom plate is arranged on the open side of the cover body. A plurality of second fixing holes are arranged on the bottom plate. After the bottom plate and the cover body are combined, the second fixing holes are screwed through by screws and the internal threads inside the cover body are threadedly connected, that is, the bottom plate and the cover body are fixed, and then a relatively closed shielding chamber is constructed inside the shielding box body 1. The shielding chamber is provided with a circuit board 4, a first interface terminal 2 and a second interface terminal 3. The shielding box body 1 made of all-metal materials will form a Faraday cage structure. When the shielding box body 1 is completely closed, the shielding box body 1 will form an equipotential body, that is, the internal potential difference is zero. Based on the effect of the electrostatic field, when the electromagnetic wave passes through the metal, it will be subjected to the reaction force generated by the charge distribution of the metal itself, causing the electromagnetic wave to be reflected and consumed inside the metal, thereby achieving electromagnetic absorption and shielding effects.

[0028] Among them, a first through hole is provided on the top end surface of the cover body, the first interface terminal 2 is provided with the first through hole, and the second end of the first interface terminal 2 is electrically connected to the first end surface of the circuit board 4, and the first end of the first interface terminal 2 is used to electrically connect to the external cable 8. A second through hole is provided on the end surface of the bottom plate, the second interface terminal 3 is provided with the second through hole, and the first end of the second interface terminal 3 is electrically connected to the second end surface of the circuit board 4, and the second end of the second interface terminal 3 is used to electrically connect to the universal terminal of the servo driver 7. The first end surface and the second end surface of the circuit board 4 are respectively engraved with a circuit that conducts from the first end surface to the second end surface, that is, the first interface terminal 2 and the second interface terminal 3 can be electrically connected through the circuit board 4, so that the servo driver universal terminal 6 does not affect the normal electrical connection function of the external cable 8 and the servo driver universal terminal 6 when the shielding box body 1 is assembled externally. Specifically, the first interface terminal 2 and the second interface terminal 3 can be fixed and electrically connected to the first end surface and the second end surface of the circuit board 4 respectively by welding.

[0029] Furthermore, a shielding pad 5 is provided around the outer edge of the bottom end surface where the shielding box body 1 fits the servo driver 7. The shielding pad 5 is made of a conductive foam material. Conductive fibers are provided inside the conductive foam, which can be used to absorb electromagnetic radiation generated inside. Metal shielding material is provided outside the conductive foam, which can reflect external electromagnetic radiation. At the same time, during the plugging process between the second interface terminal 3 and the servo driver universal terminal 6, a certain gap is often left between the bottom end surface of the shielding box body 1 and the corresponding end surface of the servo driver 7, which is used for the smooth plugging and unplugging between the second interface terminal 3 and the servo driver universal terminal 6. In order to prevent the electromagnetic radiation leaked from the servo driver universal terminal 6 from leaking again through the gap at the bottom of the shielding box body 1, a shielding pad 5 is provided in this embodiment, and the thickness of the shielding pad 5 is limited to be slightly larger than the spacing between the bottom end surface of the shielding box body 1 and the corresponding end surface of the servo driver 7. The shielding pad 5 itself has a certain elasticity. By providing the shielding pad 5, the bottom end surface of the shielding box body 1 and the corresponding end surface of the servo driver 7 are tightly fitted to achieve a sealing effect, which can further effectively prevent electromagnetic radiation from overflowing, and enhance the shielding effect against electromagnetic radiation in external space.

[0030] A device for improving the EMC performance of the non-metallic universal terminal of a servo drive provided in this embodiment greatly improves the electromagnetic compatibility performance of the universal terminal 6 of the servo drive without affecting the normal electrical connection between the universal terminal 6 of the servo drive and external equipment. Through the cooperation of the shielding box body 1 and the shielding gasket 5, based on the Faraday cage principle, the electromagnetic radiation generated by the servo drive 7 can be effectively blocked from leaking through the universal terminal and causing electromagnetic interference to other external equipment. At the same time, the electromagnetic radiation generated by other external equipment can also be effectively blocked from leaking to the external space through the universal terminal, or leaking into the inside of the servo drive 7.

[0031] Preferably, the shielding box body 1 provided in this embodiment is made of SECC electrolytic galvanized steel material. The electrolytic galvanized steel material has excellent conductivity and corrosion resistance, which can effectively ensure the stable conductivity of the shielding box body 1, realize electromagnetic wave reflection, and provide material support for the construction of the Faraday cage, thereby achieving the electromagnetic shielding effect.

[0032] Preferably, in this embodiment, the shell of the first interface terminal 2 is made of metal material, and the shell of the first interface terminal 2 and the shielding box body 1 are made of the same metal material, ensuring that a complete all-metal Faraday cage structure can be constructed to achieve an overall efficient electromagnetic shielding effect. Specifically, the first interface terminal 2 in this embodiment adopts a DSUB-25 connector, which has good versatility and can achieve quick connection with cables 8 of various types of external devices. At the same time, the DSUB-25 connector adopts a metal shell and an internal shielding structure, which can further effectively isolate and reduce electromagnetic interference. The shell of the second interface terminal 3 is made of non-metallic material to maintain plug-in compatibility with the non-metallic servo drive universal terminal 6.

[0033] Preferably, an extended mounting plate is provided laterally at the bottom of the shielding box body 1. After the shielding box body 1 is connected to the servo driver universal terminal 6, the mounting plate is affixed to the end face of the servo driver 7. A first fixing hole is provided in the mounting plate, and a screw is provided to pass through the first fixing hole and is threadedly connected to the internal threaded hole provided on the servo driver 7, thereby realizing fixed installation of the shielding box body 1, improving the installation stability of the shielding box body 1, and reducing the shear force on the servo driver universal terminal 6 and the second interface terminal 3.

[0034] Preferably, the first through hole and the second through hole are asymmetrically designed in the vertical direction of the shielding box body 1, that is, the first interface terminal 2 and the second interface terminal 3 are staggered. The specific staggered distance is not specifically limited here. The staggered distance can be further flexibly adjusted according to the actual size of the servo drive 7 and the actual position of the servo drive universal terminal 6, thereby improving the assembly flexibility of the servo drive 7 and the installation flexibility of the shielding box body 1.

[0035] The above is a detailed description of the embodiments of the present invention in conjunction with the accompanying drawings, but the present invention is not limited to the above embodiments. Even if various changes are made to the present invention, if these changes fall within the scope of the claims of the present invention and their equivalents, they still fall within the protection scope of the present invention.

Claims

1. A device for improving the EMC performance of non-metallic universal terminals of servo drives, characterized in that: include: A shielding box body made of metal material, a first interface terminal, a second interface terminal and a circuit board; The shielding box body is wrapped and covered on one side of the electrical connection end surface of the servo drive universal terminal, and is used to improve the electromagnetic compatibility of the servo drive universal terminal. The shielding box body includes a cover body and a bottom plate, and the cover body and the bottom plate are spliced ​​and fixed to form a relatively closed shielding chamber, and the circuit board is arranged in the shielding chamber; A first through hole is provided on the top end surface of the cover body, the first interface terminal is passed through the first through hole, and the second end of the first interface terminal is electrically connected to the first end surface of the circuit board, and the first end of the first interface terminal is used to be electrically connected to an external cable; a second through hole is provided on the end surface of the bottom plate, the second interface terminal is passed through the second through hole, and the first end of the second interface terminal is electrically connected to the second end surface of the circuit board, and the second end of the second interface terminal is used to be electrically connected to the universal terminal of the servo drive; the first end surface and the second end surface of the circuit board are respectively engraved with circuits that conduct from the first end surface to the second end surface, and the circuit board is used to conduct the first interface terminal and the second interface terminal, thereby achieving electrical connection between the external cable and the universal terminal of the servo drive; A surrounding and closed shielding gasket is also provided on the outer edge of the bottom end surface of the shielding box body that fits the servo driver. The shielding gasket is used to improve the sealing effect between the connecting surface of the shielding box body and the servo driver.

2. The device for improving the EMC performance of non-metallic universal terminals of servo drives according to claim 1, characterized in that: The shielding box body is made of electrolytic galvanized steel material.

3. The device for improving the EMC performance of non-metallic universal terminals of servo drives according to claim 1, characterized in that: The shell of the first interface terminal is made of metal material, and the shell of the second interface terminal is made of non-metal material.

4. The device for improving the EMC performance of non-metallic universal terminals of servo drives according to claim 3, characterized in that: The first interface terminal is a DSUB-25 connector.

5. The device for improving the EMC performance of non-metallic universal terminals of servo drives according to claim 1, characterized in that: The shielding pad is made of conductive foam material.

6. The device for improving the EMC performance of the non-metallic universal terminal of a servo drive according to claim 5, characterized in that: The thickness of the shielding pad is limited to be slightly larger than the distance between the bottom end surface of the shielding box body and the opposite end surface of the servo driver.

7. The device for improving the EMC performance of non-metallic universal terminals of servo drives according to claim 1, characterized in that: An extended mounting plate is provided laterally at the bottom of the shielding box body, and the mounting plate is attached to the end face of the servo driver. A first fixing hole is opened in the mounting plate, and a screw is provided to pass through the first fixing hole and be threadedly connected to the servo driver for fixing and installing the shielding box body.

8. The device for improving the EMC performance of non-metallic universal terminals of servo drives according to claim 1, characterized in that: A second fixing hole is provided in the bottom plate, and a screw is provided through the second fixing hole to be threadedly connected with the cover body to fix the cover body and the bottom plate.

9. The device for improving the EMC performance of non-metallic universal terminals of servo drives according to claim 1, characterized in that: The first through hole and the second through hole are asymmetrically designed in the vertical direction of the shielding box body, and are used for staggered arrangement of the first interface terminal and the second interface terminal.

10. The device for improving the EMC performance of non-metallic universal terminals of servo drives according to claim 1, characterized in that: The first interface terminal and the second interface terminal are fixedly connected to the conducting circuits of the first end surface and the second end surface of the circuit board respectively by welding.

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