Motor signal magnetic ring and processing method thereof

Abstract

The invention discloses a motor signal magnetic ring and a processing method thereof, and belongs to the technical field of motor sensors, the motor signal magnetic ring comprises a magnetic ring support installed on a motor rotor shaft, and the periphery of the magnetic ring support is in positioning connection with a magnetic ring body through an injection molding filling layer. The potential safety hazard of cracks in the magnetic ring caused by inconsistent shrinkage rate during injection molding of the signal magnetic ring can be reduced, and the reliability and the service life of the product are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of motor sensor, in particular to a motor signal magnetic ring and a processing method thereof. BACKGROUND

[0002] With the continuous development of motor manufacturing level and process, permanent magnet motor is widely used in aerospace, robots, household appliances, medical equipment and factory automation, etc. At present, motor sensors mostly use photoelectric encoder, resolver and magnetic resistance chip. The magnetic resistance chip can be integrated on PCBA due to its low cost, and has been widely used in recent years. At present, the signal excitation of the magnetic resistance chip needs to use a permanent magnet to provide a changing magnetic field. The commonly used application scene is to provide a pair of magnetic fields for the bottom shaft. In some special application scenes, the signal magnetic steel cannot be installed on the bottom shaft and needs to avoid the internal mechanism, so a ring-shaped magnetic ring is needed to provide a signal magnetic field on the magnetic ring.

[0003] The disadvantages of the existing technology are: (1) the magnetic ring is relatively fragile and cannot be used for interference press-fit assembly. The process is complex and the glue will fall off after long-term use; (2) when the support is embedded and injection molded with the magnetic ring, due to the inconsistency of shrinkage and expansion coefficient, there will be a certain proportion of cracks; (3) when the support is pressed into other parts, the magnetic ring will be broken due to stress; (4) some useless process structures also need to be filled with injection molding magnets, which wastes materials and has high cost.

[0004] Patent No. CN202405883U discloses an injection molded magnetic ring with reliable assembly and high fitting precision, which comprises a magnetic ring body, an inlaid part is arranged on the inner ring of the magnetic ring body, and the inlaid part is provided with a fitting part for assembly with a main shaft. The patent combines the inlaid part with the magnetic ring for injection molding. Due to the inconsistency of shrinkage and expansion coefficient, there will be a certain proportion of cracks. Moreover, when the magnetic ring is pressed into the rotor shaft, the magnetic ring may be broken due to stress. SUMMARY

[0005] In order to solve the above technical problems, the present application provides a motor signal magnetic ring and a processing method thereof. The signal magnetic ring has simple structure and low processing cost, can reduce the safety hazard of cracks in the magnetic ring caused by the inconsistency of shrinkage rate during injection molding of the signal magnetic ring, and improves the reliability and service life of the product.

[0006] To achieve the above purpose, the technical scheme adopted by the present application to solve its technical problems is: the motor signal magnetic ring comprises a magnetic ring support mounted on a motor rotor shaft, and the outer periphery of the magnetic ring support is connected with a magnetic ring body through an injection filling layer.

[0007] The magnetic ring support is a stamping stretch-formed annular metal support, comprising a magnetic ring mounting section matched with the magnetic ring body and an interference fit section interference fit with the motor rotor shaft.

[0008] An axial positioning portion is arranged on the magnetic ring mounting section, and the axial positioning portion comprises a positioning flange and a positioning stopper respectively arranged at both ends of the magnetic ring mounting section in the circumferential direction.

[0009] The positioning flange at the outer end of the magnetic ring support is connected to the magnetic ring mounting section in a smooth transition, and the positioning stopper at the middle of the magnetic ring support is connected to the magnetic ring mounting section and the interference fit section in a smooth transition.

[0010] A plurality of anti-rotation grooves I are arranged on the magnetic ring mounting section in the circumferential direction, and the anti-rotation grooves I are arranged in the axial direction of the magnetic ring mounting section, and both ends of the anti-rotation grooves I extend to the positioning flange and the positioning stopper respectively.

[0011] A plurality of anti-rotation grooves II are arranged on the inner side of both ends of the magnetic ring body in the circumferential direction, and the injection filling layer is filled in the anti-rotation grooves II.

[0012] The injection filling layer is arranged between the two sides and the bottom of the magnetic ring body and the outer side of the magnetic ring mounting section.

[0013] The magnetic ring body is arranged to be radially magnetized or axially magnetized.

[0014] A processing method of the motor signal magnetic ring, comprising the following steps:

[0015] Step 1: stamping stretch-forming the magnetic ring support, and pre-processing and forming the magnetic ring body;

[0016] Step 2: positioning the magnetic ring support and the magnetic ring body as inserts into an injection mold;

[0017] Step 3: forming an injection filling layer by injection filling between the magnetic ring support and the magnetic ring body.

[0018] Step 4: cooling and shaping out of the mold.

[0019] The beneficial effects of the present application are:

[0020] 1. The present application provides a signal magnetic ring comprising a magnetic ring support and a magnetic ring body, and the magnetic ring support and the magnetic ring body are integrally injection molded as inserts, an injection filling layer is formed between the magnetic ring support and the magnetic ring body, which can reduce the safety hazard of cracks in the magnetic ring caused by inconsistent shrinkage during injection molding, and also reduces the amount of magnetic material, and when the magnetic ring support is pressed and assembled into the rotor shaft, the injection filling layer can share part of the axial pressure, which can prevent the magnetic ring body from being broken by the direct force, thereby improving the reliability and service life of the product.

[0021] 2、The application is characterized in that the anti-rotation grooves are arranged on the magnetic ring body and the magnetic ring support in the circumferential direction, and the axial positioning part including the positioning flange and the positioning stop is arranged on the magnetic ring support, so that the strength and stability of the connection of the magnetic ring body, the magnetic ring support and the injection filling layer are improved, the shaking of the magnetic ring body in the axial and radial directions is avoided, and the anti-vibration and impact performance of the product is improved.

[0022] 3、The magnetic ring support in the application is formed by stamping and drawing, which reduces the manufacturing cost compared with the traditional machining forming mode; the anti-rotation grooves arranged on the magnetic ring support in the circumferential direction not only play the role of anti-rotation, but also can be used for positioning during manufacturing and magnetization, thereby improving the consistency of the product; the multi-pole magnetization mode is adopted, the accuracy of the sensor is improved, and the control accuracy of the control system is improved. BRIEF DESCRIPTION OF DRAWINGS

[0023] The content expressed by each drawing in the specification of the application and the marks in the drawings are briefly described as follows:

[0024] Figure 1 is the axonometric view of the motor signal magnetic ring of the application;

[0025] Figure 2 is the full cross-sectional view of the motor signal magnetic ring of the application;

[0026] Figure 3 is the axonometric view of the magnetic ring support in the application;

[0027] Figure 4 is the axonometric view of the magnetic ring body in the application;

[0028] The marks in the above drawings are as follows: 1. magnetic ring support, 11. magnetic ring mounting section, 12. interference fit section, 13. positioning flange, 14. positioning stop, 15. anti-rotation groove I, 2. injection filling layer, 3. magnetic ring body, 31. anti-rotation groove II. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical scheme and advantages of the embodiments of the application more clear, the technical scheme in the embodiments will be clearly and completely described below with reference to the drawings in the embodiments of the application. The following embodiments are used to illustrate the application, but are not used to limit the scope of the application.

[0030] In the description of the present application, it should be noted that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0031] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integral connection; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through intermediate medium. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0032] As shown in Figures 1-4 The present application provides a motor signal magnetic ring, which comprises a magnetic ring support 1 mounted on a motor rotor shaft, and the outer periphery of the magnetic ring support 1 is connected to the magnetic ring body 3 through an injection filling layer 2. The magnetic ring support 1 and the magnetic ring body 3 are integrally injection molded as inserts, and the injection filling layer 2 is injection molded between the magnetic ring support 1 and the magnetic ring body 3. This can reduce the safety hazard of cracks in the magnetic ring caused by inconsistent shrinkage during injection molding, and also reduce the amount of magnetic material used. In addition, when the magnetic ring support 1 is pressed into the rotor shaft, the injection filling layer 2 can share part of the axial pressure, preventing the magnetic ring body 3 from being directly affected by the force and breaking, thereby improving the reliability and service life of the product.

[0033] Specifically, the magnetic ring support 1 is a stamped and stretched annular metal support, which reduces the manufacturing cost compared to the traditional machining forming method. The magnetic ring support 1 includes a magnetic ring mounting section 11 matched with the magnetic ring body 3 and an interference fit section 12 interference fit with the motor rotor shaft. The inner diameter of the magnetic ring mounting section 11 is smaller than that of the interference fit section 12, and a positioning stop 14 is formed at the connection between the magnetic ring mounting section 11 and the interference fit section 12, which can limit the positioning of the entire signal magnetic ring. Moreover, since the installation of the signal magnetic ring is only through the interference fit section 12 matched with the rotor shaft, the magnetic ring body 3 mounted on the magnetic ring mounting section 11 is basically not affected by the radial force, and the injection filling layer 2 can share part of the axial pressure, further avoiding the breakage of the magnetic ring body 3 during installation of the signal magnetic ring.

[0034] The axial positioning part is arranged on the magnetic ring mounting section 11, the axial positioning part comprises a positioning flange 13 and a positioning stop 14 which are respectively arranged on the two ends of the magnetic ring mounting section 11 in the circumferential direction, and the injection molding filling layer 2 and the magnetic ring body 3 are arranged between the positioning flange 13 and the positioning stop 14, so that the magnetic ring body 3 can be axially positioned. The positioning flange 13 at the outer end of the magnetic ring support 1 is connected to the magnetic ring mounting section 11 in a smooth transition, and the positioning stop 14 at the middle part of the magnetic ring support 1 is connected to the magnetic ring mounting section 11 and the interference fit section 12 in a smooth transition, thereby avoiding the problem of stress concentration at the positioning flange 13 and the positioning stop 14.

[0035] The magnetic ring mounting section 11 is provided with a plurality of anti-rotation grooves I 15 which are arranged at intervals in the circumferential direction, the anti-rotation grooves I 15 are arranged in the axial direction of the magnetic ring mounting section 11, and the two ends of the anti-rotation grooves I 15 extend to the positioning flange 13 and the positioning stop 14, respectively. The anti-rotation grooves I 15 are axially protruding towards the injection molding filling layer 2, and the plurality of anti-rotation grooves I 15 extend into the injection molding filling layer 2, so that the magnetic ring support 1 is firmly connected to the injection molding filling layer 2, thereby avoiding the problem of relative rotation between them. The anti-rotation grooves I 15 can not only play a role in anti-rotation positioning of the magnetic ring support 1 when the signal magnetic ring is injection molded, but also can be used for positioning during manufacturing and magnetization, thereby improving the consistency of the product.

[0036] Specifically, the two ends of the magnetic ring body 3 are respectively provided with a plurality of anti-rotation grooves II 31 which are arranged at intervals in the circumferential direction, and the plurality of anti-rotation grooves II 31 at the two ends of the magnetic ring body 3 can be arranged relatively or staggered, and the injection molding filling layer 2 fills in the anti-rotation grooves II 31, thereby avoiding the problem of relative rotation between the magnetic ring body 3 and the injection molding filling layer 2.

[0037] The anti-rotation grooves are arranged in the circumferential direction on the magnetic ring body 3 and the magnetic ring support 1, and the axial positioning part comprising the positioning flange 13 and the positioning stop 14 is arranged on the magnetic ring support 1, so that after the magnetic ring body 3, the magnetic ring support 1 and the injection molding filling layer 2 are connected, the strength and stability of the connection are improved, the magnetic ring body 3 is prevented from shaking in the axial and radial directions, and the anti-vibration impact performance of the product is improved.

[0038] Specifically, the injection molding filling layer 2 is an injection molding plastic body, the plastic body has good ductility and high connection strength after cooling, and can share part of the axial pressure. The injection molding filling layer 2 is arranged between the two sides and the bottom of the magnetic ring body 3 and the outer side of the magnetic ring mounting section 11, thereby further ensuring the connection strength and stability between the magnetic ring body 3 and the magnetic ring support 1.

[0039] In addition, the magnetic ring body 3 is arranged to be radially magnetized or axially magnetized, and a multi-pole magnetization mode is adopted, thereby improving the accuracy of the sensor and the control accuracy of the control system.

[0040] The processing method of the motor signal magnetic ring comprises the following steps:

[0041] Step 1: stamping and drawing of the magnetic ring support 1, while the magnetic ring body 3 is pre-processed.

[0042] The method of stamping and drawing of the magnetic ring support 1 is to place the annular metal piece on the stamping and drawing machine for stamping and drawing to form the magnetic ring mounting section 11 and the interference fit section 12.

[0043] The method of pre-processing of the magnetic ring body 3 is the existing processing method, which is not described here.

[0044] Step 2: position the magnetic ring support 1 and the magnetic ring body 3 as inserts into the injection mold.

[0045] The shape of the injection mold needs to ensure that after the magnetic ring support 1 and the magnetic ring body 3 are placed in it, the mold and the magnetic ring support 1 and the magnetic ring body 3 form a mold cavity space that is the shape of the injection filling layer 2, i.e. wrapped between the two sides of the magnetic ring body 3 and the bottom and the outside of the magnetic ring mounting section 11.

[0046] Step 3: form the injection filling layer 2 between the magnetic ring support 1 and the magnetic ring body 3 by injection filling, i.e. inject plastic material into the mold cavity of the mold under certain pressure and temperature to form the injection filling layer 2.

[0047] Step 4: cooling and setting out of the mold to form the signal magnetic ring with the above structure.

[0048] In summary, the signal magnetic ring of the present application has a simple structure and low processing cost, which can reduce the safety hazard of cracks in the magnetic ring caused by inconsistent shrinkage during injection molding of the signal magnetic ring, and improve the reliability and service life of the product.

[0049] The above is only to illustrate some principles of the present application with diagrams, and this specification is not intended to limit the present application to the specific structure and application range shown and described, so all possible modifications and equivalents are within the scope of the patent application.

Claims

1. A motor signal magnetic ring, characterized in that, It includes a magnetic ring bracket mounted on the rotor shaft of a motor, wherein the outer periphery of the magnetic ring bracket is positioned and connected to the magnetic ring body through an injection-molded filler layer.

2. The motor signal magnetic ring according to claim 1, characterized in that: The magnetic ring bracket is configured as a ring-shaped metal bracket formed by stamping and stretching, including a magnetic ring mounting section that mates with the magnetic ring body and an interference fit section that is interference fit with the motor rotor shaft.

3. The motor signal magnetic ring according to claim 2, characterized in that: The magnetic ring mounting section is provided with an axial positioning part, which includes a positioning flange and a positioning stop respectively provided at both ends of the magnetic ring mounting section along the circumferential direction.

4. The motor signal magnetic ring according to claim 3, characterized in that: The positioning flange at the outer end of the magnetic ring bracket is smoothly connected to the magnetic ring mounting section, and the positioning stop in the middle of the magnetic ring bracket is smoothly connected to the magnetic ring mounting section and the interference fit section.

5. The motor signal magnetic ring according to claim 3, characterized in that: Multiple anti-rotation grooves I are spaced apart along the circumference of the magnetic ring mounting section. The anti-rotation grooves I are arranged along the axial direction of the magnetic ring mounting section, and the two ends of the anti-rotation grooves I extend to the positioning flange and the positioning stop, respectively.

6. The motor signal magnetic ring according to claim 5, characterized in that: Multiple anti-rotation grooves II are provided at intervals along the circumference on the inner sides of both ends of the magnetic ring body, and the injection-molded filling layer is filled in the anti-rotation grooves II.

7. The motor signal magnetic ring according to claim 1, characterized in that: The injection-molded filler layer is disposed between the two sides and the bottom of the magnetic ring body and the outer side of the magnetic ring mounting section.

8. The motor signal magnetic ring according to claim 1, characterized in that: The magnetic ring body is configured to be radially magnetized or axially magnetized.

9. A method for processing a motor signal magnetic ring as described in any one of claims 1 to 8, characterized in that, Includes the following steps: Step 1: The magnetic ring bracket is stamped and stretched into shape, while the magnetic ring body is pre-processed and formed at the same time; Step 2: Position the magnetic ring bracket and the magnetic ring body as inserts into the injection mold; Step 3: An injection-molded filler layer is formed between the magnetic ring support and the magnetic ring body by injection molding. Step 4: Cool and set before demolding.

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