Sensor end cover and sensor

Abstract

The utility model discloses a sensor end cover and a sensor, the sensor comprises a stator and a rotor, the stator is provided with a stator skeleton, the stator skeleton is wound with a coil winding, and the stator skeleton comprises a metal skeleton and a plastic layer wrapping the metal skeleton; the metal framework comprises a bottom and a surrounding side wall, the side wall is used for covering the extending part of the coil winding, a fixing part is arranged on the inner surface of the side wall, and when the metal framework covers the end part of the sensor, the metal framework can be fixed on the stator framework through the fixing part. According to the utility model, the defect that the sensor is susceptible to external strong magnetic interference due to weak working signals is overcome, and the metal framework is wrapped by the plastic layer, so that the insulating and rust-proof functions of the framework are realized. After the sensor is provided with the electromagnetic interference protection end cover, the anti-electromagnetic interference capability can be enhanced, and the electromagnetic environment applicability of the sensor is enhanced.

Description

Technical Field

[0001] The utility model relates to the technical field of sensors, in particular to a sensor end cover and a sensor. Background Art

[0002] Nowadays, position and angle sensors such as magnetoresistive resolvers, transformer resolvers, and angular displacement sensors are widely used in electromechanical drive scenarios. However, these sensors are all electromagnetic principle-based sensors with a very weak working magnetic field, generally 1-10 mT, and are easily interfered by the electromagnetic fields emitted by external frequency converters or motor permanent magnets; this causes distortion of the output voltage signal of the sensor, ultimately increasing the electrical error of the sensor and even making it unable to work properly.

[0003] Conventional methods for sensors to resist electromagnetic interference include: increasing the installation distance of the sensor to increase the magnetic resistance of electromagnetic field transmission, which undoubtedly increases the installation space and limits the installation space for using the sensor; or adding a metal shielding cover for protection, which will increase the volume, weight, and cost of the sensor. Summary of the Utility Model

[0004] The purpose of the utility model is to solve the technical problem that existing sensors cannot be applied to strong magnetic interference environments, and to propose a sensor end cover and a sensor.

[0005] The technical problem of the utility model is solved by the following technical solutions:

[0006] A sensor end cover, the sensor includes a stator and a rotor, a stator skeleton is arranged on the stator, and a coil winding is wound on the stator skeleton, including: a metal skeleton and a plastic layer covering the metal skeleton;

[0007] The metal skeleton includes a bottom and a surrounding side wall, a through hole is arranged at the center of the bottom, the diameter of the through hole is larger than the outer diameter of the rotor, the side wall is used to cover the extended part of the coil winding, and a fixing part is arranged on the inner surface of the side wall. When the metal skeleton covers the end of the sensor, the metal skeleton can be fixed on the stator skeleton through the fixing part.

[0008] In some embodiments, the fixing part includes a buckle, and a buckle groove corresponding to the buckle is arranged on the stator skeleton, and the buckle can be buckled with the buckle groove to fix the metal skeleton on the stator skeleton.

[0009] In some embodiments, the plastic layer covers the metal skeleton by injection molding or spraying.

[0010] In some embodiments, the metal skeleton is made of silicon steel sheets.

[0011] In some embodiments, the thickness of the silicon steel sheet is 0.3 mm - 1 mm.

[0012] In some embodiments, at least a part of the connection between the bottom and the side wall is provided with a convex structure for controlling the pressing depth.

[0013] The present utility model also provides a sensor, including a stator and a rotor. A stator skeleton is arranged on the stator, and the sensor end cover as described above is fixedly covered on at least one end.

[0014] The beneficial effects of the present utility model compared with the prior art include:

[0015] A sensor end cover and a sensor of the present utility model solve the problem that the working signal of the sensor is weak and vulnerable to strong external magnetic interference through a sensor electromagnetic interference protection end cover with a metal skeleton. In addition, after the metal skeleton is wrapped with a plastic layer, the insulation and rust prevention functions of the skeleton are realized. After the sensor is installed with the electromagnetic interference protection end cover, the anti-electromagnetic interference ability can be enhanced, and the electromagnetic environment applicability of the sensor is enhanced. Description of the Drawings

[0016] Figure 1 is a schematic structural diagram of the sensor end cover from an angle in an embodiment of the present utility model;

[0017] Figure 2 is a schematic structural diagram of the sensor end cover from another angle in an embodiment of the present utility model;

[0018] Figure 3 is a schematic structural diagram of the sensor end cover from another angle in an embodiment of the present utility model;

[0019] Figure 4 is a schematic structural diagram of the sensor from an angle in an embodiment of the present utility model;

[0020] Figure 5 is a sectional view of the sensor in an embodiment of the present utility model;

[0021] Figure 6 is Figure 5 a partial sectional view of the sensor end cover at circle A in

[0022] The reference numerals are as follows:

[0023] 1 - metal skeleton, 11 - bottom, 111 - through hole, 12 - side wall, 121 - buckle, 13 - convex structure, 2 - plastic layer, 3 - sensor skeleton, 4 - sensor body. Detailed Embodiments

[0024] The present utility model will be further described below with reference to the accompanying drawings and in conjunction with preferred embodiments. It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments may be combined with each other.

[0025] It should be noted that the orientation terms such as left, right, up, down, top, bottom, etc. in this embodiment are only relative concepts to each other or are referenced based on the normal use state of the product, and should not be considered restrictive.

[0026] In order to solve the disadvantages that the working signal of the sensor is weak and vulnerable to strong external magnetic interference, the embodiment of the present utility model designs a sensor end cover. Referring to Figures 1-6 , the sensor in the sensor end cover of the embodiment of the present utility model includes a stator and a rotor. A stator skeleton 3 is arranged on the stator, and a coil winding is wound around the stator skeleton 3. The sensor end cover of the embodiment of the present utility model includes: a metal skeleton 1 and a plastic layer 2 covering the metal skeleton 1;

[0027] Referring to Figures 1-2 , the metal skeleton 1 includes a bottom 11 and an enclosing side wall 12. A through hole 111 is arranged at the center of the bottom 11. The diameter of the through hole 111 is larger than the outer diameter of the rotor (because the center position of the resolver is the rotor and there is a rotating shaft passing through, so the diameter of the through hole 111 is slightly larger than the outer diameter of the rotor). The side wall 12 is used to cover the extended part of the coil winding. A fixing part is arranged on the inner surface of the side wall 12. When the metal skeleton 1 covers the end of the sensor, the metal skeleton 1 can be fixed to the stator skeleton 3 through the fixing part.

[0028] In this embodiment, the fixing part includes a buckle 121. A buckle groove corresponding to the buckle 121 is arranged on the stator skeleton 3. The buckle 121 can be buckled with the buckle groove to fix the metal skeleton 1 to the stator skeleton 3. The plastic layer 2 covers the metal skeleton 1 by spraying a non-metallic material or by injection molding to form an insulator. After the metal skeleton 1 is plastic-wrapped, the insulation and rust prevention functions of the metal skeleton 1 are realized, and at the same time, the winding is protected from damage. The metal skeleton 1 is made of silicon steel sheets with a thickness of 0.5 mm. In some embodiments, the material of the metal skeleton 1 is a soft magnetic material with high magnetic permeability and low resistivity. According to the principle of electromagnetic induction, a magnetic field induces a voltage field, voltage / resistance = current. When the resistance is small, the current is large, and the magnetic field energy can be effectively consumed.

[0029] The sensor protective end cover of this embodiment can be applied to position and angle sensors such as magnetoresistive resolvers, transformer resolvers, and angular displacement sensors to play an anti-electromagnetic interference protection role. These sensors are composed of a stator and a rotor, and a double-sided plastic skeleton is arranged on the stator by injection molding. The sensor end cover is installed on the plastic skeleton of the sensor. A groove (snap groove) structure is arranged on the plastic skeleton, and a protrusion (snap part 121) structure is arranged on the sensor end cover. The two form a snap pair and are connected and fixed to the plastic skeleton through the snap structure. Five snap parts 121 are circumferentially arranged on the inner surface of the side wall 12. The structure of the sensor end cover of this embodiment is a circular bowl-shaped structure, which can effectively wrap the winding extension parts at both ends of the stator. In this embodiment, a protrusion structure 13 is arranged at the connection between a part of the bottom 11 and the side wall 12. The protrusion structure 13 is used to control the pressing depth and make way for the groove on the skeleton at the vacant position below the snap part 121. In a specific embodiment of the present invention, the sensor anti-electromagnetic interference sensor end cover structure takes the sensor end cover of a multi-pole magnetoresistive resolver with an outer diameter of 37 mm as an example. The material of the metal skeleton 1 of the sensor end cover structure is 50W470, and it is processed into a bowl-shaped structure by metal sheet metalworking. The thickness of the metal skeleton 1 is 0.5 mm, and the outer diameter of the metal skeleton 1 is 32 mm. The metal skeleton 1 is wrapped with a sprayed nylon plastic material on the outer layer to form an insulator; the sensor end cover is insulated from the sensor stator core.

[0030] Reference Figures 4-5 , this embodiment also discloses a sensor, including a stator and a rotor (sensor body 4). A stator skeleton 3 is arranged on the stator, and the above-mentioned sensor end cover is fixedly covered on at least one end. In this embodiment, the sensor end cover is installed in pairs on both sides of the magnetoresistive resolver. The sensor end cover can be installed on one side or in pairs on both sides of the sensor. The sensor is installed on products such as motors by relying on the rear cover side. If the rear cover is made of steel, single-sided protection is sufficient. If the rear cover is made of non-magnetic and conductive materials such as aluminum, double-sided installation is required. The sensor end cover is insulated from the sensor stator core because if the two are not insulated, the magnetic field will be transmitted to the product along the sensor end cover, which will instead cause the interference to intensify.

[0031] The embodiment of the utility model can improve the electromagnetic interference resistance of the sensor without increasing the volume, weight and cost of the sensor. This is because the central part of the electromagnetic interference protection end cover structure of the sensor is the metal skeleton 1. When the electromagnetic field passes through the metal skeleton 1, since the metal skeleton 1 is a conductive soft magnetic material with high magnetic permeability and low resistivity, eddy currents will be excited in the metal skeleton 1, and heat loss will be generated in the metal skeleton 1 by the eddy currents; the magnetic field energy will be consumed, resulting in a sharp attenuation of the magnetic field passing through the metal skeleton 1 and reaching the inside of the skeleton, achieving the purpose of electromagnetic shielding protection. This simple electromagnetic protection structure does not increase the number of parts of the product, and the cost does not increase significantly, which has great practical value.

[0032] The above content is a further detailed description of the utility model in combination with specific preferred embodiments, and it cannot be determined that the specific implementation of the utility model is only limited to these descriptions. For those skilled in the technical field to which the utility model belongs, without departing from the concept of the utility model, several equivalent substitutions or obvious modifications can be made, and as long as the performance or use is the same, it should be regarded as belonging to the protection scope of the utility model.

Claims

1. A sensor end cover, the sensor comprising a stator and a rotor, the stator being provided with a stator frame, the stator frame being wound with a coil winding, characterized in that: include: A metal frame and a plastic layer covering the metal frame; The metal skeleton includes a bottom and surrounding side walls, a through hole is arranged at the center of the bottom, the diameter of the through hole is larger than the outer diameter of the rotor, the side wall is used to cover the protruding part of the coil winding, and a fixing part is arranged on the inner surface of the side wall. When the metal skeleton covers the end of the sensor, the metal skeleton can be fixed to the stator skeleton through the fixing part.

2. The sensor end cap according to claim 1, characterized in that: The fixing portion comprises a buckle, and a buckle groove corresponding to the buckle is arranged on the stator frame. The buckle can be buckled with the buckle groove to fix the metal frame on the stator frame.

3. The sensor end cap according to claim 1, characterized in that: The plastic layer covers the metal frame by injection molding or spraying.

4. The sensor end cap according to claim 1, characterized in that: The metal skeleton is made of silicon steel sheets.

5. The sensor end cap according to claim 4, characterized in that: The thickness of the silicon steel sheet is 0.3mm-1mm.

6. The sensor end cap according to claim 1, characterized in that: At least a portion of the bottom portion connected to the side wall is provided with a protruding structure, and the protruding structure is used to control the pressing depth.

7. A sensor, comprising a stator and a rotor, wherein a stator frame is provided on the stator, characterized in that: At least one end of the fixed cover has a sensor end cover as described in any one of claims 1-6.

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