Self-adhesive rivet-free iron core and production process therefor

Abstract

The present invention relates to the technical field of iron core production, and in particular to a self-adhesive rivet-free iron core and a production process therefor, the production process comprising the following steps: pre-determining the positions of silicon steel sheets on a steel strip having a self-adhesive coating; stamping the outer sides of the silicon steel sheets to form silicon steel sheets and two frames; performing half-shear stamping on the joints between the silicon steel sheets and the frames, so that the silicon steel sheets are displaced from the frames by a certain distance; performing shaping, so that the silicon steel sheets and the frames are located on a same plane; cutting off the steel strip, so that the silicon steel sheets and the frames form separate pieces; stacking the plurality of pieces together, punching clinching points on the frames, and caulking the pieces into a whole by means of the clinching points; heating the plurality of pieces to melt the self-adhesive coating, cooling the pieces, and curing the self-adhesive coating to fix the plurality of stacked silicon steel sheets together; fixing the silicon steel sheets, and separating the frames from the silicon steel sheets to obtain iron core subunits; and arranging the plurality of iron core subunits in the circumferential direction, and snap-fitting adjacent iron core subunits to form a complete iron core.

Description

A self-adhesive rivetless iron core and its manufacturing process Technical Field

[0001] This invention relates to the field of tooling technology, and in particular to a self-adhesive rivetless iron core and its manufacturing process. Background Technology

[0002] The iron core is the central part of the motor, composed of multiple stamped silicon steel sheets stacked together. Common connection methods for iron core products include snap-fit, welding, riveting, and adhesive bonding. Snap-fit ​​and riveting methods compromise the integrity of the product design, thus affecting performance. While welding does not compromise integrity, it typically involves assembling individual sheets and then welding them together; product quality is limited by the precision of the sheet-arranging tooling, and it is inefficient. Adhesive bonding also ensures product integrity, but the adhesive itself is not a mature technology and is expensive, making it unsuitable for long-term mass production.

[0003] To address this, a method of injection molding on the outside of silicon steel sheets was designed to achieve a rivetless core. However, in order not to affect the subsequent assembly and use of the core, injection molding could only be performed on a portion of the sidewall of the silicon steel sheets, which resulted in insufficient connection strength between the silicon steel sheets inside the plastic. Summary of the Invention

[0004] The technical problem to be solved by the present invention is: in order to solve the technical problems in the prior art, the present invention provides a self-adhesive rivetless iron core production process.

[0005] The technical solution adopted by this invention to solve its technical problem is: a self-adhesive rivetless iron core production process, comprising the following steps:

[0006] S1. Use a steel strip with a self-adhesive coating and pre-determine the position of the silicon steel sheet on the steel strip;

[0007] S2. Stamping is performed on the outside of the silicon steel sheet to remove some of the waste material, exposing part of the outer contour of the silicon steel sheet. The remaining waste material on the steel strip forms two frames that connect the silicon steel sheets, with the two frames located on both sides of the silicon steel sheet.

[0008] S3. Perform half-shear punching at the connection between the silicon steel sheet and the frame, so that the silicon steel sheet is punched out of the frame a certain distance.

[0009] S4. Shape the silicon steel sheet so that it is on the same plane as the frame;

[0010] S5. Cut the steel strip to form separate sheets of silicon steel and frame;

[0011] S6. Stack multiple pieces together, punch out fastening points on the frame, and rivet them together into a whole through the fastening points;

[0012] S7. Heat multiple sheets to melt the self-adhesive coating, and use the melted self-adhesive coating material to connect adjacent silicon steel sheets. Then cool the sheets to solidify the self-adhesive coating, and finally connect the silicon steel sheets into one piece.

[0013] S8. Separate the silicon steel sheet from the frame to obtain the iron core sub-unit;

[0014] S9. Arrange multiple core sub-units along the circumferential direction, and interlock adjacent core sub-units to form a complete core.

[0015] The self-adhesive rivetless iron core production process of the present invention uses steel strips with self-adhesive coatings. After stacking multiple sheets, the sheets are heated to melt the self-adhesive coating, and then cooled to solidify the self-adhesive coating again. This allows adjacent silicon steel sheets to be connected together. Compared with injection molding, the bonding area between silicon steel sheets connected by the self-adhesive coating is larger and the fit is tighter, resulting in a more reliable connection strength.

[0016] Furthermore, in S7, the tablet is heated and cooled by a downstream device. The downstream device first places the tablet in an environment of 180-220 degrees Celsius and puts the tablet under pressure. After maintaining this state for one cycle, the tablet is then placed in an environment of 0 degrees Celsius and kept under pressure for another cycle.

[0017] Furthermore, one cycle is 1-3 minutes.

[0018] Furthermore, in S7, the tablets are heated in an oven and placed inside the oven at a temperature of 100 to 180 degrees Celsius for 1 hour.

[0019] Furthermore, in step S8, the silicon steel sheets are first injection molded to form a whole, and then the silicon steel sheets are separated from the frame to obtain the iron core sub-unit.

[0020] Furthermore, the downstream equipment includes an upper mold frame and a lower mold frame. The lower mold frame is equipped with a heating component and a cooling component, and the upper mold frame is equipped with a pressing component. The pressing component has two pressure rods that extend into the heating component and the cooling component respectively to press the silicon steel sheet.

[0021] Furthermore, the heating assembly includes a concave mold and a heating coil. The concave mold is mounted on a lower mold frame, and a heating groove for accommodating the sheet is provided inside the concave mold. The heating coil is arranged around the side wall of the heating groove.

[0022] Furthermore, the cooling assembly includes a cooling tray and a cooling side plate. The cooling tray is mounted on the lower mold frame and is used to place the sheet. The cooling side plate is mounted on the cooling tray and is arranged around the cooling tray in the circumference to form a cooling groove for accommodating the sheet.

[0023] Furthermore, the lower mold frame is provided with a first limiting post, and the upper mold frame is provided with a second limiting post. When the upper mold frame and the lower mold frame are closed, the first limiting post and the second limiting post abut against each other.

[0024] Furthermore, the lower mold frame is provided with two ejector rods, which are located below the heating tank and the cooling tank respectively, so as to lift the sheet body. The two ejector rods are connected to the same linkage plate, and the ejector rods are threadedly connected to the linkage plate.

[0025] The beneficial effects of this invention are:

[0026] 1. By using steel strips with self-adhesive coating, multiple sheets are stacked and heated to melt the self-adhesive coating. Then, the sheets are cooled to solidify the self-adhesive coating again, thereby connecting adjacent silicon steel sheets together. Compared with injection molding, the bonding area between silicon steel sheets connected by self-adhesive coating is larger and the fit is tighter, resulting in more reliable connection strength.

[0027] 2. By keeping multiple silicon steel sheets under pressure during heating and cooling, the tightness of the bonding between adjacent silicon steel sheets and the connection strength between adjacent silicon steel sheets can be guaranteed.

[0028] 3. The linkage plate and ejector rod make it easy to eject the plates in the heating and cooling tanks at the same time, saving costs. At the same time, the ejector rod is threaded to the linkage plate, making it easy to adjust the height of the ejector rod. Attached Figure Description

[0029] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0030] Figure 1 is a schematic diagram of the structure of the sheet formed by the frame and the silicon steel sheet in this invention.

[0031] Figure 2 is a schematic diagram illustrating the silicon steel sheet in this invention.

[0032] Figure 3 is a schematic diagram illustrating the framework in this invention.

[0033] Figure 4 is a schematic diagram illustrating the downstream equipment in this invention.

[0034] Figure 5 is a schematic diagram illustrating the upper and lower pressure plates in this invention.

[0035] Figure 6 is a schematic diagram illustrating the internal heating plate in this invention.

[0036] In the diagram: 1. Frame; 12. First snap-fit ​​surface; 121. Connecting groove; 16. Fastening point; 2. Silicon steel sheet; 23. First connecting surface; 231. Connecting protrusion; 3. Upper mold frame; 31. Pressure rod; 311. Upper pressure plate; 312. Lower pressure plate; 313. Adjusting bolt; 314. Compression spring; 315. Countersunk hole; 32. Second limiting post; 4. Lower mold frame; 41. Heating assembly; 411. Die; 412. Heating coil; 413. Heating groove; 414. Inner heating plate; 42. Cooling assembly; 421. Cooling tray; 422. Cooling side plate; 423. Cooling groove; 424. Cooling pipe; 43. First limiting post; 44. Ejector rod; 45. Linkage plate. Detailed Implementation

[0037] The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams, illustrating only the basic structure of the invention, and therefore only show the components relevant to the invention.

[0038] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, features defined with "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more. In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly, for example, as a fixed connection, a detachable connection, or an integral connection; as a mechanical connection or an electrical connection; as a direct connection or an indirect connection through an intermediate medium; or as a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0039] This invention discloses a manufacturing process for a self-adhesive, rivetless iron core.

[0040] Referring to Figures 1 and 2, a manufacturing process for a self-adhesive rivetless iron core includes the following steps:

[0041] S1. Use a steel strip with a self-adhesive coating, and pre-determine the position of the silicon steel sheet 2 on the steel strip. The steel strip can be made of Shanghai Baosteel steel, and the model can be B25A230Z, B35A300Z, or B20.

[0042] S2. A stamping process is performed on the outer side of the silicon steel sheet 2 to remove some waste material, exposing a portion of the outer contour of the silicon steel sheet 2. The remaining waste material on the steel strip forms two frames 1 connecting the silicon steel sheets 2, located on both sides of the silicon steel sheet 2. Referring to Figures 1 to 3, each side of the silicon steel sheet 2 has a first snap-fit ​​surface 12, and the two frames 1 have a first connecting surface 23 that mates with the first snap-fit ​​surface 12. The first connecting surface 23 has a connecting groove 121, and the first snap-fit ​​surface 12 has a connecting protrusion 231 that mates with the connecting groove 121. Multiple silicon steel sheets 2 are provided along the length of the frames 1; in this embodiment, there are three.

[0043] S3. Perform a half-shear punching at the connection between the silicon steel sheet 2 and the frame 1, so that the silicon steel sheet 2 is punched out of the frame 1 by a certain distance.

[0044] S4. Shape the silicon steel sheet 2 so that it is on the same plane as the frame 1.

[0045] S5. Cut the steel strip to form the silicon steel sheet 2 and the frame 1 into separate sheets.

[0046] S6. Stack multiple pieces together, punch out snap points 16 on frame 1, and rivet them together into a whole through snap points 16.

[0047] S7. Multiple sheets are heated to melt the self-adhesive coating. The molten coating connects adjacent silicon steel sheets 2. The sheets are then cooled to solidify the self-adhesive coating, ultimately bonding the silicon steel sheets 2 together. During heating, the sheets are heated and cooled using a downstream device. The downstream device first places the stacked sheets in an environment of 180-220 degrees Celsius and keeps them under pressure for one cycle. Then, the sheets are placed in an environment of 0 degrees Celsius, maintaining the pressure for another cycle. One cycle is 1-3 minutes; in this embodiment, it is 1 minute. Keeping the sheets under pressure during both heating and cooling facilitates control of the product's behavior tolerances during the curing process.

[0048] In another embodiment, the tablet is not under pressure when heated; it is only under pressure when cooled.

[0049] Referring to Figures 4 to 6, the downstream equipment includes an upper mold frame 3 and a lower mold frame 4. The lower mold frame 4 is equipped with a heating component 41 and a cooling component 42. The upper mold frame 3 is equipped with a pressing component. The pressing component can be in two sets or in one set. When there are two sets of pressing components, the two sets of pressing components correspond to the heating component 41 and the cooling component 42, respectively. When there is only one set of pressing components, it only corresponds to the cooling component 42. The pressing component includes a pressure rod 31 and a pressing member connected to the pressure rod 31. The pressing member is used to extend into the cooling component 42 and press the silicon steel sheet 2. The top of the pressure rod 31 is fixedly connected to the upper mold frame 3 so as to move synchronously with the upper mold frame 3.

[0050] The pressing component includes an upper pressure plate 311, an elastic element, and a lower pressure plate 312. The upper pressure plate 311 is fixedly connected to the bottom of the pressure rod 31. The elastic element is located between the upper pressure plate 311 and the lower pressure plate 312. The upper pressure plate 311 and the lower pressure plate 312 are connected by an adjusting bolt 313. The head of the adjusting bolt 313 passes through the upper pressure plate 311 and is threadedly connected to the lower pressure plate 312, so that the adjusting bolt 313 can not only connect the upper pressure plate 311 and the lower pressure plate 312, but also adjust the distance between the upper pressure plate 311 and the lower pressure plate 312. The elastic element can be a compression spring 314, which is sleeved on the adjusting bolt 313. The bottom of the upper pressure plate 311 has a countersunk hole 315 to accommodate the compression spring 314. The lower pressure plate 312 is used to contact the top surface of the tablet. When the pressing rod is pressed down, the lower pressure plate 312 first contacts the top surface of the tablet. At this time, the pressing rod continues to press down, causing the compression spring 314 to be compressed until the upper pressure plate 311 contacts the lower pressure plate 312. That is, the pressure applied to the tablet is provided by the compression spring 314, thereby providing a stable and controllable pressure to the tablet. At the same time, the distance between the upper pressure plate 311 and the lower pressure plate 312 can be adjusted by adjusting the adjusting bolt 313, thereby adjusting the pressure applied to the tablet by the lower pressure plate 312.

[0051] Specifically, the heating assembly 41 includes a concave mold 411 and a heating coil 412. The concave mold 411 is mounted on the lower mold frame 4. The concave mold 411 has a heating groove 413 for accommodating the sheet. The heating coil 412 is arranged around the side wall of the concave mold 411 to uniformly heat the sheet. A spiral groove is provided vertically on the side wall of the concave mold 411. The heating coil 412 is at least partially located within the spiral groove and is in contact with the groove wall to increase the contact area between the heating coil 412 and the concave mold 411, thereby improving heat transfer. Using the heating coil 412 for heating improves the heating effect and facilitates the installation of a temperature sensor in the heating groove 413, allowing for precise temperature control of the heating groove 413 via the built-in temperature control system. The heating of the sheet requires strict control; overheating may cause adhesive overflow, while insufficient temperature or time may result in insufficient bonding strength between adjacent silicon steel sheets 2.

[0052] In another embodiment, an inner heating plate 414 is connected to the bottom surface of the heating groove 413. The inner heating plate 414 is inserted into the sheet body, thereby facilitating an increase in the heating effect on the silicon steel sheet. The shape of the inner heating plate 414 can conform to the inner side of the outer surface and the outer side of the silicon steel sheet.

[0053] More specifically, the cooling assembly 42 includes a cooling tray 421 and a cooling side plate 422. The cooling tray 421 is mounted on the lower mold frame 4 and is used to place the sheet. The cooling side plate 422 is mounted on the cooling tray 421 and is arranged around the circumference of the cooling tray to form a cooling groove 423 for accommodating the sheet. A cooling pipe 424 is spirally wound on the side wall of the cooling side plate 422. The cooling pipe 424 is connected to a cooling device, which provides cooling water to the cooling pipe to achieve circulating cooling, thereby facilitating the control of the cooling temperature. The cooling device can be a refrigerator, and the cooling pipe 424 can be a flat copper pipe. Compared with a round copper pipe, the flat copper pipe has a larger contact area with the cooling side plate 422, resulting in a better cooling effect.

[0054] The lower mold frame 4 is connected to a first limiting post 43, and the upper mold frame 3 is connected to a second limiting post 32. When the upper mold frame 3 and the lower mold frame 4 are closed, the first limiting post 43 and the second limiting post 32 abut against each other, which facilitates the control of the distance between the upper mold frame 3 and the lower mold frame 4.

[0055] To facilitate the ejection of the sheet, two ejector rods 44 are vertically inserted inside the lower mold frame 4. The two ejector rods 44 are located below the heating tank 413 and the cooling tank 423, respectively, to lift the sheet. The bottom of the two ejector rods 44 is connected to the same linkage plate 45, allowing the linkage plate to simultaneously drive both ejector rods 44. The two ejector rods 44 are threadedly connected to the linkage plate 45 to adjust their height.

[0056] It should be noted that when the inner heating plate 414 is connected to the bottom surface of the heating tank 413, the ejector rod 44 is set as a hollow rod structure to avoid interference with the inner heating plate 414.

[0057] During operation, by controlling the heating coil 412 and the cooling device, the heating and cooling times for the sheet are made the same, allowing the heating assembly 41 and the cooling assembly 42 to share a single press. This also enables synchronous feeding and discharging, saving costs and improving efficiency. After the two sets of sheets are placed into the heating tank 413 and the cooling tank 423 respectively, the upper mold frame 3 moves downward, causing the two pressure rods 31 to extend into the heating tank 413 and the cooling tank 423 respectively, pressing the two sets of sheets under pressure.

[0058] In another embodiment, the film can also be heated in an oven by placing the film inside the oven and maintaining the temperature at 100 to 180 degrees Celsius for 1 hour. The advantage is that a regular oven can be used without additional modification, resulting in lower costs; however, a regular oven has poor heating effect on the film, making it difficult to keep multiple films under pressure, and also requires the addition of a separate cooling component 42.

[0059] S8. Separate the silicon steel sheet 2 from the frame 1 to obtain the iron core subunit. After the silicon steel sheet 2 is bonded by the self-adhesive coating, the strength of the silicon steel sheet 2 is sufficient, so it can be further injection molded, or injection molding can be stopped. If injection molding is required, after the self-adhesive coating has cured, the silicon steel sheet 2 is first injection molded so that multiple silicon steel sheets 2 form a whole injection molded part, and then the silicon steel sheet 2 is separated from the frame 1 to obtain the iron core subunit.

[0060] In addition, the self-adhesive coating method is simpler and less expensive than injection molding.

[0061] S9. Arrange multiple core sub-units along the circumferential direction, and interlock adjacent core sub-units to form a complete core.

[0062] Working principle: By using steel strips with self-adhesive coating, multiple sheets are stacked and heated to melt the self-adhesive coating. Then, the sheets are cooled to solidify the self-adhesive coating again, thereby connecting adjacent silicon steel sheets 2 together. Compared with injection molding, the bonding area between silicon steel sheets 2 connected by self-adhesive coating is larger and the fit is tighter, so the connection strength is more reliable.

[0063] Based on the above-described preferred embodiments of the present invention, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A manufacturing process for a self-adhesive, rivetless iron core, characterized in that, Includes the following steps: S1. Use a steel strip with a self-adhesive coating and pre-determine the position of the silicon steel sheet (2) on the steel strip; S2. Stamping is performed on the outside of the silicon steel sheet (2) to remove some of the waste material, so that a part of the outer contour of the silicon steel sheet (2) is exposed. The remaining waste material on the steel strip forms two frames (1) connecting the silicon steel sheet (2), and the two frames (1) are located on both sides of the silicon steel sheet (2). S3. Perform half-shear punching on the connection between the silicon steel sheet (2) and the frame (1) to punch the silicon steel sheet (2) out of the frame (1) by a certain distance. S4. Shape the silicon steel sheet (2) so that it is on the same plane as the frame (1); S5. Cut the steel strip to form a separate sheet from the silicon steel sheet (2) and the frame (1); S6. Stack multiple pieces together, punch out buckle points (16) on the frame (1), and rivet them together into a whole through the buckle points (16); S7. Heat multiple sheets to melt the self-adhesive coating, and use the melted self-adhesive coating material to connect adjacent silicon steel sheets (2). Then cool the sheets to solidify the self-adhesive coating, and finally connect the silicon steel sheets (2) into one piece. The tablet is heated and cooled by a downstream device. The tablet is first placed in an environment of 180 to 220 degrees Celsius and maintained for one cycle. Then the tablet is placed in an environment of 0 degrees Celsius and kept under pressure for another cycle. One cycle is 1 to 3 minutes. The downstream equipment includes an upper mold frame (3) and a lower mold frame (4). The lower mold frame (4) is provided with a heating component (41) and a cooling component (42). The upper mold frame (3) is provided with a pressing component. The pressing component includes a pressing rod (31) and a pressing member connected to the pressing rod (31). The pressing member is used to extend into the cooling component (42) and press the silicon steel sheet (2). The top of the pressing rod (31) is fixedly connected to the upper mold frame (3) so as to move synchronously with the upper mold frame (3). The pressing component includes an upper pressing plate (311), an elastic element, and a lower pressing plate (312). The upper pressing plate (311) is connected to the bottom of the pressing rod (31). The elastic element is located between the upper pressing plate (311) and the lower pressing plate (312). The upper pressing plate (311) and the lower pressing plate (312) are connected by an adjusting bolt (313). The head of the adjusting bolt (313) passes through the upper pressing plate (311) and is threadedly connected to the lower pressing plate (312), so that the adjusting bolt (313) can not only connect the upper pressing plate (311) and the lower pressing plate (312), but also adjust the distance between the upper pressing plate (311) and the lower pressing plate (312). S8. Separate the silicon steel sheet (2) from the frame (1) to obtain the iron core subunit; S9. Arrange multiple core sub-units along the circumferential direction, and interlock adjacent core sub-units to form a complete core.

2. The self-adhesive rivetless iron core production process according to claim 1, characterized in that, In S7, the tablets are heated in an oven and placed inside the oven at a temperature of 100 to 180 degrees Celsius for 1 hour.

3. The self-adhesive rivetless iron core production process as described in claim 1, characterized in that, In step S8, the silicon steel sheet (2) is first injection molded so that multiple silicon steel sheets (2) form a whole, and then the silicon steel sheet (2) is separated from the frame (1) to obtain the iron core sub-unit.

4. The self-adhesive rivetless iron core production process as described in claim 1, characterized in that, The heating assembly (41) includes a concave mold (411) and a heating coil (412). The concave mold (411) is mounted on the lower mold frame (4). The concave mold (411) is provided with a heating groove (413) for accommodating the sheet. The heating coil (412) is arranged around the side wall of the heating groove (413).

5. The self-adhesive rivetless iron core production process as described in claim 4, characterized in that, The cooling assembly (42) includes a cooling tray (421) and a cooling side plate (422). The cooling tray (421) is mounted on the lower mold frame (4) and is used to place the sheet. The cooling side plate (422) is mounted on the cooling tray (421) and is arranged around the cooling tray in the circumference to form a cooling groove (423) for accommodating the sheet.

6. The self-adhesive rivetless iron core production process as described in claim 5, characterized in that, The lower mold frame (4) is provided with a first limiting post (43), and the upper mold frame (3) is provided with a second limiting post (32). When the upper mold frame (3) and the lower mold frame (4) are closed, the first limiting post (43) and the second limiting post (32) abut against each other.

7. The self-adhesive rivetless iron core production process as described in claim 6, characterized in that, The lower mold frame (4) is provided with two ejector rods (44), which are located below the heating tank (413) and the cooling tank (423) respectively, so as to lift the sheet. The two ejector rods (44) are connected to the same linkage plate (45), and the ejector rods (44) are threadedly connected to the linkage plate (45).

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