Laminated iron core stamping in-die rotary manufacturing method

Abstract

The invention discloses a laminated iron core stamping in-mold rotation manufacturing method, which belongs to the field of iron core manufacturing, and comprises the steps of lamination stamping, blanking, mold rotation, pressurization, electrified curing, molding and the like, and lamination is heated by electrifying, so that the processes of lamination heating and lamination curing are synchronous, and no time difference exists; in the lamination stacking process, the mold rotates, so that the mass distribution of the manufactured iron core is uniform; the protrusions on the inner circles of the laminations form spiral contact surfaces, friction force between the iron core and the rotating shaft is enhanced, and heat dissipation efficiency is improved through the spiral cooling channels.

Description

Technical Field

[0001] The invention relates to the field of iron core manufacturing, and in particular to a method for manufacturing a laminated iron core by rotation in a stamping die. Background Art

[0002] The stator and rotor core of the motor includes the stator core and the rotor core, both of which are made of stacked silicon steel sheets (punching sheets). Common methods of fixing the laminated structure of the core punching sheets are stacking riveting and welding. The core punching sheets of the stacking riveting fixation method are stamped with stacking rivets. When stacked, the two adjacent core punching sheets are connected to each other through the stacking rivets on them. The core punching sheets of the welding fixation method have no stacking rivets. When stacked, the two adjacent motor stator core punching sheets are welded together.

[0003] Due to the existence of overlapping rivets and the manufacturing process, there may be a certain gap between the adjacent punching sheets of the motor stator core after overlapping rivets, which will affect the magnetic properties of the core. Since the overlapping rivets are omitted in the welding fixed core punching, the gap between the adjacent punching sheets is reduced, but the inward welding of the core during welding will affect the magnetic circuit of the core, thereby affecting the electromagnetic properties of the core, and thus reducing the efficiency of the produced motor, thereby increasing the energy consumption of the motor.

[0004] Gluing fixation can avoid riveting gaps and affect the core magnetic circuit during welding, but the glue fixing process requires heating and curing the laminates in the mold. However, during heating, the heat in the mold is transferred from the outside to the inside, resulting in the laminate curing process. The outside is cured first and the inside is cured later, resulting in a time difference, resulting in tiny gaps and surface flatness that does not meet the requirements. In addition, the uneven thickness of the laminated sheet will also lead to uneven quality distribution of the core product and unsatisfactory surface flatness. Summary of the invention

[0005] In order to overcome the deficiencies of the prior art, one of the objectives of the present invention is to provide a method for manufacturing a laminated core by rotating in a stamping die, wherein the laminates are solidified simultaneously and the core mass is evenly distributed.

[0006] One of the purposes of the present invention is achieved by the following technical solution:

[0007] A method for manufacturing a laminated core by internal rotation in a stamping die, comprising the following steps:

[0008] Laminate stamping: a plate is stamped to form a plurality of laminates, each of which has a plurality of protrusions on its inner circle, the plurality of protrusions are evenly spaced and distributed on the inner circle of the laminate, and the end of each protrusion is a curved surface;

[0009] Blanking: The laminate formed by stamping falls into the mold. During the falling process of the laminate, the laminate is sprayed so that the self-adhesive powder covers the laminate;

[0010] Mold rotation: When two adjacent laminates fall into the mold, the mold drives the laminate that has fallen into the mold to rotate. The angle of each rotation is A. The angle of mold rotation is 0-B+N*C, where B is the angle formed by the end of the protrusion and the center of the laminate, N is an integer, and C is the angle between two adjacent arc surfaces, so that the protrusion ends of the two adjacent laminates falling into the mold are staggered and continuous;

[0011] Pressurization: When the stacked laminations in the die reach a preset height, a punch is used to contact the stacked laminations to compress the stacked laminations;

[0012] Power-on curing: Power is applied to the mold to heat up the pressed laminates, so that the self-adhesive powder on the laminates melts and solidifies, thereby fixing and connecting two adjacent laminates;

[0013] Molding: The power to the mold is turned off, and the stacked laminations form an iron core. The inner circles of the multiple laminations form through holes, and multiple spiral contact surfaces are formed on the inner walls of the through holes, and a spiral cooling channel is formed between two adjacent contact surfaces.

[0014] Furthermore, the laminated core in-die rotation manufacturing method also includes a thickness measurement step and a height measurement step. The thickness measurement step is located before the laminate stamping step. The thickness measurement is specifically: multi-point measurement of the laminate stamping area of ​​the plate, measuring the thickness of the plate at different positions in the stamping area, so as to obtain the thickness of the laminates at different positions that are about to fall after being stamped. The height measurement step is specifically: measuring the real-time heights of the laminates at different positions stacked in the die, and determining the value of N according to the real-time heights of the laminates at different positions stacked in the die and the thicknesses of the laminates at different positions that are about to fall.

[0015] Furthermore, the goal of selecting the value of N is to make the quality of the stacked sheets uniform.

[0016] Furthermore, multi-point measurement of the stamping area includes multi-point measurement of circumferential thickness and multi-point measurement of radial thickness, and the real-time height of different positions of the stacked laminations in the mold includes multi-point measurement of circumferential height and multi-point measurement of radial height, and the circumferential quality uniformity takes precedence over radial quality uniformity in the goal of taking the value of N.

[0017] Furthermore, in the pressurizing step, when the punch falls to contact the stacked laminations, the punch falls twice, and the first falling speed of the punch is lower than the second falling speed.

[0018] Furthermore, in the pressurizing step, the contact surface between the punch and the laminate is a conical surface.

[0019] Furthermore, in the mold rotating step, L is the length of the arc surface, and R is the radius of the arc surface.

[0020] Furthermore, in the blanking step, the self-adhesive powder is epoxy resin powder.

[0021] Furthermore, in the forming step, the protrusions on the same contact surface form a stepped structure along the height direction.

[0022] Furthermore, in the electrical curing step, alternating current is used to energize the mold.

[0023] Compared with the prior art, the laminated core stamping die inner rotation manufacturing method of the present invention includes the steps of laminate stamping, blanking, die rotation, pressurization, power-on curing and molding, and adopts power-on heating of the laminate to make the laminate itself generate heat, and the laminate curing process is synchronized without time difference; during the laminate stacking process, the die rotates to make the mass distribution of the manufactured core uniform; the protrusions on the inner circle of the laminate form a spiral contact surface, which enhances the friction between the core and the rotating shaft, and the spiral cooling channel improves the heat dissipation efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a flow chart of the laminated core stamping die internal rotation manufacturing method of the present invention;

[0025] Figure 2 is a schematic diagram of the lamination;

[0026] Figure 3 It is a schematic diagram of the local structure of the iron core.

[0027] In the figure: 10, lamination; 11, protrusion; 20, contact surface; 30, cooling channel. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] It should be noted that when a component is referred to as being "fixed to" another component, it may be directly on the other component or there may be another intermediate component through which it is fixed. When a component is considered to be "connected to" another component, it may be directly connected to the other component or there may be another intermediate component at the same time. When a component is considered to be "set on" another component, it may be directly set on the other component or there may be another intermediate component at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only.

[0030] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0031] See also Figures 1 to 3 , a laminated core stamping die internal rotation manufacturing method, comprising the following steps:

[0032] Stamping of the laminate 10: a plate is stamped to form a plurality of laminates 10, each of which has a plurality of protrusions 11 on its inner circle, the plurality of protrusions 11 being evenly spaced and distributed on the inner circle of the laminate 10, and an end of each protrusion 11 being a curved surface;

[0033] Blanking: The laminate 10 formed by stamping falls into the mold. During the falling process of the laminate 10, the laminate 10 is sprayed so that the self-adhesive powder covers the laminate 10;

[0034] Mold rotation: When two adjacent laminates 10 fall into the mold, the mold drives the laminate 10 that has fallen into the mold to rotate. The angle of each rotation is A. The angle of mold rotation is 0-B+N*C, where B is the angle formed by the end of the protrusion 11 and the center of the laminate 10, N is an integer, and C is the angle between two adjacent arc surfaces, so that the ends of the protrusions 11 of the two adjacent laminates 10 that fall into the mold are staggered and continuous;

[0035] Pressurization: When the stacked laminations 10 in the die reach a preset height, a punch is used to contact the stacked laminations 10 so that the stacked laminations 10 are pressed tightly;

[0036] Power-on curing: Power is applied to the mold to heat up the compressed laminate 10, so that the self-adhesive powder on the laminate 10 melts and solidifies, so that two adjacent laminates 10 are fixedly connected;

[0037] Molding: The power to the mold is turned off, and the stacked laminations 10 form an iron core. The inner circles of the multiple laminations 10 form through holes, and multiple spiral contact surfaces 20 are formed on the inner walls of the through holes. A spiral cooling channel 30 is formed between two adjacent contact surfaces 20.

[0038] In order to make the core mass evenly distributed, the laminated core stamping die internal rotation manufacturing method also includes a thickness measurement step and a height measurement step, and the thickness measurement step is located before the stamping step of the laminate 10. The thickness measurement is specifically: multi-point measurement is performed on the stamping area of ​​the laminate 10 of the plate, and the multiple test points are evenly distributed along the circumferential direction or radial direction. The thickness of the plate at different positions in the stamping area is measured, so as to obtain the thickness of the laminate 10 formed by stamping at different positions.

[0039] The height measurement step is specifically as follows: measuring the real-time height of different positions of the stacked laminations 10 in the mold, with multiple test points evenly distributed circumferentially or radially, and determining the value of N according to the real-time height of different positions of the stacked laminations 10 in the mold and the thickness of different positions of the laminations 10 to be dropped. The goal of the value of N is to make the quality of the stacked laminations 10 uniform. The multi-point measurement of the stamping area includes multi-point measurement of the circumferential thickness and multi-point measurement of the radial thickness. The real-time height of different positions of the stacked laminations 10 in the mold includes multi-point measurement of the circumferential height and multi-point measurement of the radial height. The goal of the value of N is uniform circumferential quality over uniform radial quality. Therefore, the angle of rotation of the mold must first meet the staggered and continuous ends of the protrusions 11 of the two adjacent laminations 10 falling into the mold to form multiple spiral contact surfaces 20, enhance the friction between the iron core and the rotating shaft, and the spiral cooling channel 30 improves the heat dissipation efficiency. In the process of rotating the laminations 10 to form the spiral contact surface 20, it plays a certain role in the uniform distribution of the quality of the iron core. However, in the process of rotating the laminations 10 to form the spiral contact surface 20, there are multiple options for the rotation angle, that is, there are multiple values ​​of N. The value of N is determined according to the real-time heights at different positions and the thicknesses at different positions of the laminations 10 that are about to fall, which can further make the quality of the manufactured iron core uniform.

[0040] Specifically, in the blanking step, the self-adhesive powder is epoxy resin powder.

[0041] In the pressurizing step, when the punch falls and contacts the stacked laminations 10, the punch falls twice, and the first falling speed of the punch is lower than the second falling speed. That is, the initial pressing is performed at a speed of 1-3mm / s, and then the rapid pressing is performed at a speed of 10-20mm / s, to ensure that the pressing process is both accurate and efficient. Start slowly and then fast. At the beginning, in order to make the combination of the punch and the lamination more reasonable and accurate, a certain amount of deformation is left for the lamination. First, each lamination is deformed partially, and then quickly solidified by electric current, so as to ensure that the top lamination will not run out and that it is evenly stressed. The contact surface between the punch and the lamination 10 is a conical surface, which further prevents the top lamination from moving.

[0042] In the mold rotation step, B=L / R, L is the arc length, and R is the arc radius.

[0043] In the energized curing step, alternating current is applied to the mold.

[0044] In the forming step, the protrusions 11 on the same contact surface 20 form a stepped structure in the height direction.

[0045] Compared with the prior art, the lamination 10 iron core stamping die inner rotation manufacturing method of the present invention adopts the steps of lamination 10 stamping, blanking, die rotation, pressurization, power-on curing and molding, and adopts power-on heating of the lamination 10 to make the lamination 10 itself heat up, and the curing process of the lamination 10 is synchronized without time difference; during the stacking process of the lamination 10, the die rotates to make the mass distribution of the manufactured iron core uniform; the protrusion 11 on the inner circle of the lamination 10 forms a spiral contact surface 20, which enhances the friction between the iron core and the rotating shaft, and the spiral cooling channel 30 improves the heat dissipation efficiency. Specifically, when the rotating shaft extends into the through hole of the iron core, the spiral contact surface 13 conflicts with the outer wall of the rotating shaft, and the groove and the outer wall of the rotating shaft form a cooling channel 30, and the cooling channel 30 is spiral. Since the contact surface is spiral, the contact surface of the iron core and the outer wall of the rotating shaft is staggered in the axial direction and distributed on the entire periphery, which increases the friction between the rotating shaft and the rotor iron core. Due to the existence of the cooling channel 30, the heat generated when the shaft drives the iron core to rotate can be dissipated from the cooling channel 30, and the cooling channel 30 is spiral-shaped, and has higher heat dissipation efficiency than the linear cooling channel in the prior art.

[0046] The above embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, which are equivalent modifications and improvements made to the above embodiments based on the essential technology of the present invention, and all of them belong to the protection scope of the present invention.

Claims

1. A method for manufacturing a laminated core by rotating in a stamping die, characterized in that: The following steps are involved: Laminate stamping: a plate is stamped to form a plurality of laminates, each of which has a plurality of protrusions on its inner circle, the plurality of protrusions are evenly spaced and distributed on the inner circle of the laminate, and the end of each protrusion is a curved surface; Blanking: The laminate formed by stamping falls into the mold. During the falling process of the laminate, the laminate is sprayed so that the self-adhesive powder covers the laminate; Mold rotation: When two adjacent laminates fall into the mold, the mold drives the laminate that has fallen into the mold to rotate. The angle of each rotation is A. The angle of mold rotation is 0-B+N*C, where B is the angle formed by the end of the protrusion and the center of the laminate, N is an integer, and C is the angle between two adjacent arc surfaces, so that the protrusion ends of the two adjacent laminates falling into the mold are staggered and continuous; Pressurization: When the stacked laminations in the die reach a preset height, a punch is used to contact the stacked laminations to compress the stacked laminations; Power-on curing: Power is applied to the mold to heat up the pressed laminates, so that the self-adhesive powder on the laminates melts and solidifies, thereby fixing and connecting two adjacent laminates; Molding: The power to the mold is turned off, and the stacked laminations form an iron core. The inner circles of the multiple laminations form through holes, and multiple spiral contact surfaces are formed on the inner walls of the through holes, and a spiral cooling channel is formed between two adjacent contact surfaces.

2. The laminated core stamping die internal rotation manufacturing method according to claim 1, characterized in that: The laminated core in-die rotation manufacturing method also includes a thickness measurement step and a height measurement step. The thickness measurement step is located before the laminate stamping step. The thickness measurement is specifically: multi-point measurement is performed on the laminate stamping area of ​​the plate, and the thickness of the plate at different positions in the stamping area is measured, so as to obtain the thickness of the laminates at different positions that are about to fall after being stamped. The height measurement step is specifically: measuring the real-time heights of the laminates at different positions stacked in the die, and determining the value of N according to the real-time heights of the laminates at different positions stacked in the die and the thicknesses of the laminates at different positions that are about to fall.

3. The laminated core stamping die internal rotation manufacturing method according to claim 2, characterized in that: The goal of selecting the value of N is to make the quality of the stacked sheets uniform.

4. The laminated core stamping die internal rotation manufacturing method according to claim 3, characterized in that: The multi-point measurement of the stamping area includes multi-point measurement of the circumferential thickness and multi-point measurement of the radial thickness. The real-time height of different positions of the stacked laminations in the mold includes multi-point measurement of the circumferential height and multi-point measurement of the radial height. Among the objectives of the N value, circumferential quality uniformity takes precedence over radial quality uniformity.

5. The laminated core stamping die internal rotation manufacturing method according to claim 1, characterized in that: In the pressurizing step, when the punch falls to contact the stacked laminations, the punch falls twice, and the first falling speed of the punch is lower than the second falling speed.

6. The laminated core stamping die internal rotation manufacturing method according to claim 1, characterized in that: In the pressurizing step, the contact surface between the punch and the laminate is a conical surface.

7. The laminated core stamping die internal rotation manufacturing method according to claim 1, characterized in that: In the mold rotating step, L is the length of the arc surface, and R is the radius of the arc surface.

8. The laminated core stamping die internal rotation manufacturing method according to claim 1, characterized in that: In the blanking step, the self-adhesive powder is epoxy resin powder.

9. The laminated core stamping die internal rotation manufacturing method according to claim 1, characterized in that: In the forming step, the protrusions on the same contact surface form a stepped structure along the height direction.

10. The laminated core stamping die internal rotation manufacturing method according to claim 1, characterized in that: In the electrical curing step, alternating current is used to energize the mold.

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