JPS6246252B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a laminated core for electrical equipment, which is formed by laminating a plurality of electromagnetic steel sheets.

Conventionally, the method of bundling multiple thin electromagnetic steel sheets together to form a laminated core for electrical equipment has often been by tightening them with rivets or clamps, but each method requires auxiliary materials and extra processing man-hours. need.

Welding is also widely used, but it has drawbacks such as the laminated core being distorted by heat and the need for welding equipment.

As a conventional method for forming local parts of an electromagnetic steel sheet and fitting the parts together, there is a method in which a circular half-cutting protrusion 2 and a half-cutting recess 3 are fitted together, as shown in FIGS. 1 and 2. , has the disadvantage of weak binding strength. As another method, as shown in FIGS. 3 to 5, there is a method in which they are connected to each other using trapezoidal protrusions whose apexes form a flat portion 4 surrounded by two parallel lines. In this method, the effective contact area 5 is small and the acting force 6 of the connection is applied in only two directions, as shown by the arrows. Also, as shown in an enlarged view in FIG. It has the disadvantage that strong bonding force cannot be obtained due to factors such as latent component forces. Furthermore, as shown in FIGS. 6 to 8, this protrusion forming punch requires re-sharpening of the three cutting edge surfaces 8 into accurate chevron shapes every time it wears out, and the difficulty of precision control is also a drawback. .

An object of the present invention is to provide a laminated iron core for an electrical device, which is formed by forming a protrusion that provides a strong bonding force by press working and bundling electromagnetic steel plates having the protrusion.

An embodiment of the present invention will be described below with reference to FIGS. 9 to 17. Figure 9 is a plan view of the stator core of a rotating electrical machine bound by six half-open protrusions (slots are omitted in the figure), and Figure 10 is a
FIG. 11 is an enlarged plan view of the projection, FIG. 12 is a side view of FIG. 11, FIG. 13a is a front view of FIG. 11, and FIG. 13b is a front view of the stacked state. Figure 14 is a front view of the punch.
15 is a sectional view taken along the arrow line in FIG. 14, FIG. 16 is a plan view of the die, and FIG. 17 is a sectional view taken along the arrow line in FIG. 16.

First, the punching die will be explained. The cross section of the cutting edge 13 of the punch for punching has a substantially concave lens shape as shown in FIG. 15, and this substantially concave lens shape is formed up to the axial center of the punch as shown in FIG. 14. Since the cutting edge 13 has a substantially concave lens cross-sectional shape, the depression angles of the four corners of the cutting edge 13 are acute angles with respect to the circular shape of the punch diameter. On the other hand, the die has a cylindrical shape as shown in FIG.

The electromagnetic steel sheet 1a is inserted between these punches and the die, and a plurality of half-cut protrusions 9 in the shape of a seamed ball are bored at regular intervals near the outer periphery of the electromagnetic steel sheet 1a. As shown in FIG. 11, this protrusion 9 is first cut into a shallow circular shape.
Next, a part of the circumference is punched out using both edges of the cutting edge 13, and a plurality of notches 10 (two in the figure) are provided in each of the circumferences. By forming this notch portion 10, a notch hole 10a is bored in the electromagnetic steel sheet 1a.

At the same time, a substantially concave lens-shaped stepped convex portion 16 is formed in a half-opened state. Both end surfaces of this stepped convex portion 16 are notched portions 10, and both body portions are provided with the stepped convex portion 1.
There is a connecting band 17 in the shape of a convex lens along the step line 15 along the line of the substantially concave lens shape due to the protrusion of 6;
The stepped convex portion 16 is connected to the electromagnetic steel plate 1a via this connecting band 17.

On the other hand, on the back side of the stepped convex part 16 due to the protrusion of this protrusion part 9, the back side of this stepped convex part 16 and the connecting band 1
A recess 12 is formed in a circle with the notch hole 10a of No.7.
(see FIG. 13a) is formed.

In the above punching process, the cutting edge 13 has a substantially concave lens cross-sectional shape and the four corners of the cutting edge 13 are formed at acute angles with respect to the circular shape of the punch diameter. Edges 11 cut at an acute angle with respect to the circumference of the protrusion 9 along the line of cut 15 are formed near the side surfaces. or,
At the same time, edges 11a are formed in the vicinity of the four corner sides of the back surface of the stepped convex portion 16 (=the back surface of the connecting band 17) corresponding to the edges 11.

As described above, the notch 10, the edge 11, the stepped convex part 16, the connecting band 17, etc. have a substantially seamed ball shape when viewed from the front, and protrude into a weight shape when viewed in cross section (see Figure 12). A half-open protrusion 9 is formed.

Next, the function of this protrusion 9 will be explained. The electromagnetic steel sheets 1a punched out with the protrusions 9 by press work are stacked in a prescribed number of sheets while the protrusions 9 are press-tightly fitted into the recesses 12 of the next electromagnetic steel sheet 1a to be overlapped, resulting in an electrical device as shown in FIG. A stator core for a rotating electric machine is formed. This press-tight fit between the protrusion 9 and the recess 12 is achieved through the cutout hole 1 of the recess 12 formed in the other electromagnetic steel sheet 1a, which overlaps with the notch 10 at both ends of the protrusion 9 formed in the electromagnetic steel sheet 1a.
Another electrical steel sheet 1 in which the electrical steel sheet 1a is press-tightly fitted and the stepped convex portions 16 formed on the electrical steel sheet 1a overlap.
The back surface of the stepped convex portion 16 (connection band 17
(same as the back surface between). In particular, the four corners of the stepped convex portion 16 are curved and widened because the stepped convex portion 16 has a substantially concave lens shape, and the vicinity of the four corners are opened by press punching, and the repulsive force due to the punching is as shown by the solid line arrows in Fig. 11. A strong acting force 6a that expands to the left and right in the circumferential direction
Work as. On the other hand, the stepped convex portion 1 forming the concave portion 12
The back surface of the stepped convex portion 16 into which the connector 6 is tightly fitted is also the back surface of the convex lens-shaped connecting band 17, and the four corners of this connecting band 17 are also subjected to forces that expand left and right in the circumferential direction.
This is because the acting force 6b acts as if the stepped convex portion 16 is contracted in the left and right directions in the circumferential direction as shown by the dotted arrows near the four corners of the stepped convex portion 16. Then, the stepped convex portion 16 and the connecting band 1
Edges 11 and 11a are formed on the four corner sides of the back surface of 7, respectively. For this reason, the recess 12 is
A tight fit cannot be achieved unless the stepped convex portion 16 is pushed onto the edge 11a of the connecting band 17 while forcing the edge 11a into the edge 11. After the close fit, the acting forces 6a and 6b form a curved line. Since they work together near the four corners of the wide-end shape, they are strongly fixed. The locking force of this embodiment is stronger than the conventional one due to the interaction of the acting forces 6a and 6b and the press-tight fit between the edges 11 and 11a.

In order to investigate the cohesive force caused by this bond, when testing was carried out under the severe conditions of lifting the stator core with the stacking direction up and down, the peeling force acts in the vertical straight direction, so the conventional method shown in Figure 3 was used. In the case of a protrusion in which the binding point is a direct shape, only the acting force 6 in the linear direction is applied, so the binding force is weak and peeling occurs. On the other hand, in this embodiment, the acting force 6 acting on the binding portion in the range indicated by the dashed line A in FIG.
The interaction force of a and 6b and the edge 11, both of which have a curved part and the edge 11 has an acute angle, so the peeling force acts on the binding part as a component force, so it can be easily removed due to the strong binding force. Does not peel off.
Incidentally, the results of the cohesive force test showed that the cohesive force of this embodiment was about 7.5 times that of Conventional Example 1.

Therefore, the circular diameter of the protrusion 9 can be reduced, and when this is used in a stator core, the magnetic flux flow is less inhibited, resulting in a small stator core with less loss. This prevents the electromagnetic steel sheets 1a from peeling off from the laminated core as a single unit or as a laminate due to vibration or shock due to insufficient binding force during binding or transportation work in the manufacturing process of the stator core, or during transportation to the next process. In addition to improving the reliability of the stator core's vibration resistance and impact, the product price will be reduced due to fewer accidental repairs. Furthermore, when incorporated into an electric motor as a stator core, the binding force is strong against electromagnetic and mechanical vibrations of the electric motor, so there is no resonance, and the vibration and noise of the electric motor are reduced.

On the other hand, in the case of this embodiment, during the punching operation with the punch shown in FIGS. 14 and 15, the cutting edge 13 of the punch
Even when the punch is worn out, the cross section of the punch is approximately concave lens-shaped, and the cutting edge 13 is flat and not in the shape of a mountain as in the conventional case, so the polishing work is simple as flat polishing, and dimensional control is also easy. Further, the die is a simple cylindrical die, and the cutting edge 14 can be easily reground by flat surface polishing.

The size, number, and arrangement of the bundling protrusions are determined by the size of the product, the amount of stacking, electrical characteristics, etc., and the space where the protrusions are provided. There are various shapes of the protrusions, such as rectangles and polygons, but a circular shape is extremely advantageous because of ease of application, ease of manufacturing the protrusion forming jig, ease of repolishing, and repair. Figure 18 shows the shape of a protrusion in a modified example of the present invention, which is formed by a circular punch with a groove provided in the axial direction and a circular die, resulting in a wide contact surface and several edges. Can be strongly bonded.

As described above, according to the present invention, there is provided a substantially seamed ball-shaped half-opening protrusion having a substantially concave lens shape having a circular notch at both ends and an edged stepped protrusion; By tightly extruding the recesses formed by the protruding parts, a laminated core can be obtained with stronger binding between adjacent electromagnetic steel plates than conventional protrusion binding, making the binding stable and easy to apply to large products. There is a certain effect. Other advantages include ease of manufacturing and maintenance of processing jigs.

[Brief explanation of the drawing]

Fig. 1 is a plan view of a conventional half-cut protrusion, Fig. 2 is a sectional view taken along the - line of Fig. 1, Fig. 3 is a plan view of a conventional chevron-shaped protrusion, and Fig. 4 is a - of Fig. 3. 5 is an enlarged sectional view of FIG. 4, FIG. 6 is a front view of a conventional chevron protrusion forming punch, FIG. 7 is a side view of FIG. 6, and FIG. 8 is a side view of FIG. 6 is a bottom view, FIG. 9 is a plan view of a laminated iron core for electrical equipment showing one embodiment of the present invention, FIG. 10 is a side view of FIG. 9, and FIG. 11 is a protrusion according to one embodiment of the present invention. Fig. 12 is a side view of Fig. 11, Fig. 13a is a plan view of
is a front view of FIG. 11, FIG. 13b is a front view showing a laminated state, FIG. 14 is a front view of a protrusion forming punch showing an embodiment of the present invention, and FIG. 15 is a front view of the - line in FIG. FIG. 16 is a plan view of a protrusion forming die showing an embodiment of the present invention, and FIG.
Figure 7 is a sectional view taken along the - line in Figure 16;
FIG. 18 is a plan view of a modified example of the protrusion shape. 1, 1a...Electromagnetic steel plate, 9...Protrusion, 10...
...Notch portion, 10a...Notch hole, 11, 11a
...edge, 12 ... recess, 15 ... step line, 1
6...Stepped convex portion, 17...Connection band.

Claims (1)

[Claims] 1. In a laminated core for an electrical device in which a part of each laminated electromagnetic steel sheet protrudes from the surface of the electromagnetic steel sheet and is fitted into a recess in another overlapping electromagnetic steel sheet to be laminated and fixed, the outer periphery of the electromagnetic steel sheet Nearby, a substantially concave lens-shaped stepped convex portion having a circular notch at both ends with a notch cut out a part of the circumference along the circumference is protruded, and a stepped convex portion protruding from the circumference near the four corner sides of this stepped convex portion is provided. A plurality of half-opened protrusions with an approximately seamed ball shape formed by an acute-angled edge and a connecting band connected to the body of the stepped protrusion, and the protrusion of these protrusions form a circular shape. a notch hole drilled corresponding to the notch formed in the step, a back surface of the stepped convex portion, an edge formed on a side surface of this back surface corresponding to the edge, and a back surface of the connecting band. a concave portion,
By pressing the protrusion into the recess of another electromagnetic steel plate to be superposed, the stepped protrusion is stacked onto the back surface of the other electromagnetic steel sheet by fitting the respective edges, notches, and holes into each other. Laminated cores for electrical equipment.