JPS6151502B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a method for manufacturing a laminated iron core.

The laminated iron core of the stator or rotor of an electric motor is manufactured by punching strip iron plates made by longitudinally slitting wide iron plates into a predetermined shape in one or more rows, and then stacking and fixing the punched iron plates one after another. Ru. The cross-sectional shape of this wide steel plate in the width direction is not uniform over the entire width of the plate due to the deflection of the rolling roller when rolling the wide steel plate, but is approximately trapezoidal as shown in FIG. Therefore, a band-shaped iron plate slit to a predetermined width from this wide iron plate 1 also has a trapezoidal cross-sectional shape. In particular, for strip-shaped steel plates that are slit from the parts close to both sides of the steel plate PLa and PLb, the difference in thickness between the left and right sides is δ.
is extremely large, and this deviation increases as the plate width increases. Therefore, when a rotor or stator iron core is laminated using such strip-shaped iron plates, the cross-sectional shape of the rotor or stator of this laminated iron core also has a trapezoidal cross-sectional shape (Fig. 2). Become something. In particular, the cross section of the laminated stator must be a precise square, which poses an unacceptable problem. In particular, the thicker the stack of iron cores and the larger the outer diameter, the larger the lateral deviation, which has a very negative effect on the tilting of the slot and the perpendicularity of the shaft hole. By the way, the left and right deviation of the iron core plate thickness is 0.02
m/m, the left and right deviation of the stator core formed by laminating 70 sheets is 1.4 m/m, and the state of lamination caulking also deteriorates.

In order to solve the above-mentioned problem, the lower mold part of the station for punching out the outer shape of the laminated iron core pieces and caulking them is heated by 180 mm every time the laminated iron core pieces reach a predetermined number.
Recently, a method of manufacturing a laminated iron core has been proposed in which the laminated iron core is rotated by degrees to offset deviations in plate thickness and then fixed in a laminated manner.

However, in this method of manufacturing a laminated iron core, the lower mold part must be rotated 180 degrees at a time during the period when the lower mold part is rotatable, that is, during the period when the crank angle of the press is within a predetermined angular range. It won't happen. Therefore, in order to accurately rotate the lower mold part by 180 degrees, the rotation angle is large, so there are problems in terms of rotational positioning accuracy and in the mechanical strength and driving force of the mechanism that rotates the lower mold part. At that time, restrictions were placed on the press speed, which was limited to 200 to 300 strokes per minute at most.

The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to provide a method for manufacturing a laminated iron core that can improve the precision of the laminated iron core and increase the press speed.

According to this invention, a plurality of punching stations for punching laminated iron core pieces from a band-shaped iron core plate are provided at a plurality of locations in the feeding direction of the band-shaped iron core plate, and the laminated iron core pieces are arranged at each punching station and punched by each punching station. Rotate each blanking die by 180°/(number of punching stations) for each press stroke, and push down the punch of each punching station to the blanking state every press stroke number equal to the number of punching stations. The laminated iron core pieces are punched and caulked at a punching station.

Hereinafter, the present invention will be explained in detail based on the embodiments shown in the accompanying drawings.

FIG. 3 is a plan view of a case where two punching stations are provided in the strip feeding direction for punching out the outer shape and caulking of core pieces for stator cores in a progressive die device for manufacturing laminated iron cores, and FIG. 3 is a sectional view taken along line AA in FIG. 3. FIG. The cylindrical lower mold part (blanking die) in these stations
1 and 1' are rotatable through the interposition of bearings 2, 2', 3 and 3', and sprockets 4 and 4' are attached to their outer peripheries. The link chain 5 suspended on the sprockets 4 and 4' passes through grooves 6a and 6b provided in the mold, and is suspended on the sprocket 8 attached to the output shaft of the indexing means 7 installed outside the mold. ing. The indexing means 7 consists of a roller cam indexing device 9 and a transmission 10, as shown in FIG.

The rotation of the crankshaft of the press is transmitted to the input shaft 9a of the roller cam indexing device 9. That is, as shown in FIG. 5, a pulley 12 is attached to the end 11 of the crankshaft of the press, and the rotation of the crankshaft is controlled by the pulley 12, belt 13, pulley 14,
15, a belt 16, a pulley 17, and a universal joint 18, it is transmitted one-to-one to the input end 9a of the roller cam indexing device 9. Pulleys 12, 14, 15, and 17 have the same diameter, and pulley 1
4 and 15 are coaxial. The reference numeral 19 is a bearing device, 20 is a lower die device, 21 is an upper die device, and 22 is a press slide.

The roller cam indexing device 9 calculates a phase angle within a predetermined phase angle range within one revolution of the input shaft 9a (that is, one revolution of the crankshaft), for example, the top dead center within one revolution (one stroke) of the crankshaft as shown in FIG. The rotational driving force is transmitted to the transmission 10. Gearbox 1
0 means the rotation angle of sprockets 4 and 4' is exactly 90
This is for adjusting the rotation angle of 90 degrees, and converts the rotation transmitted from the roller cam indexing device 9 into the rotation angle of 90 degrees. This provides a rotation angle of 90 DEG to the sprocket 8 mounted on the output shaft of the transmission 10, and the lower mold parts 1, 1' are each rotated by 90 DEG.

Incidentally, a band-shaped iron core plate (strip) 28 is intermittently transferred to the lower mold portions 1, 1' at predetermined pitches. The strip 28 reaching the station of the lower mold part 1, 1' follows the imaginary line 2 as shown in FIG.
A caulking protrusion 26 and a stroke 27 are machined at a point symmetrical position with respect to the center of the laminated iron core piece 30 shown at 9 in the station in front of the station.

On the other hand, the upper die device 21 has punches 23, 23'
, a counter (not shown) for counting the number of press strokes, cams 24, 24' and solenoid 2.
5, 25' cam device. This cam device alternately energizes the solenoids 25, 25' in accordance with the count value of the counter, and alternately pushes down the punches 23, 23' in contact with the cam device to the punched state.

Therefore, the strip 28 reaching the station of the lower mold part 1, 1' is connected to the punches 23, 23' (the eighth
The laminated iron core pieces 30 punched into the lower mold parts 1 and 1' are alternately punched into the lower mold parts 1 and 1' in the shape shown by the imaginary line 29 in FIG. (not shown) punches 23, 23'
It is caulked on a pedestal 31 which is designed to be pushed up with a pressing force slightly smaller than the pressing force of . In addition,
The cylinder is configured so that each time a predetermined number of laminated iron core pieces constituting one laminated iron core are punched out and caulked, the pedestal 31 is lowered and the product laminated iron core is taken out. As is well known, a predetermined number of cut and raised protrusions 26 are punched out, and the product laminated iron cores are separated one by one by not being caulked with the previously punched laminated iron core pieces.

90 including top dead center in one press stroke
In the range of 90°, the link chain 5 is driven by an amount corresponding to a rotation angle of 90°, and the cylindrical lower die portions 1, 1' are rotated by 90° together with the sprockets 4, 4'. The laminated iron core pieces 30, which have already been punched into the lower mold part 1 and caulked together, are attached to the lower mold part 1,
Since it is in close contact with the inner circumference of 1', the lower mold part 1,
1' are rotated together. Therefore, press 2
Immediately before the punch punches out the strip alternately with each stroke, the forced rotation has already finished, and the newly punched laminated iron core piece and the uppermost laminated iron core piece that has already been punched into the lower mold part 1 are removed. 30
There is a phase shift of 180° between them. As a result, the laminated iron core piece newly punched into the lower mold part 1 is caulked to the already punched laminated iron core piece. In this way, by alternately stacking the plates with a phase shift of 180 degrees, deviations in plate thickness are canceled out, and as shown in Figure 9, the laminated iron core stator 4
The cross-sectional shape of 0 can be formed into an accurate rectangular shape.

Figure 10 shows an example in which two rows of progressive molds are used in one press. Lower mold parts 1A, 1'A and 1B, 1'B are provided at the station where each row is to be punched and crimped. These lower mold parts 1A, 1'
Sprockets 4A, 4'A and 4B, 4'B are attached to A, 1B, 1'B in the same manner as the sprocket 4 described above. And these sprockets 4A, 4'A and 4B, 4'B
A link chain 5' is hung on the sprocket 8 of the indexing means 7, and one indexing means 7 moves an angle of 90 degrees per stroke of the press.
A rotation of ° is given. Punching and caulking can be performed by one indexing means 7 not only in two rows but also in a plurality of rows of progressive molds.

In this example, two punching stations are used for punching out the outer shape and caulking of the iron core piece for the stator core in the progressive metal electrode apparatus for manufacturing the laminated iron core.
Although we have provided two locations, you are not limited to these and may provide multiple locations.
In this case, the blanking die is 180°/number of punching stations for each stroke of the press)
All you have to do is rotate it one by one. Furthermore, it goes without saying that this method can be used not only for stators but also for rotors.

As explained above, according to the present invention, when manufacturing a laminated iron core with high dimensional accuracy by canceling out the plate thickness deviation of each laminated iron core piece by rotating the laminated iron core pieces by 180 degrees and stacking them, This was achieved by rotating the blanking die in the station for punching and caulking each laminated iron core piece using the rotation of the press crankshaft. The laminating function can be easily incorporated into a progressive die device for manufacturing laminated iron cores.

In particular, a plurality of punching stations having the above-mentioned blanking dies are provided in the feeding direction of the strip iron core plate, and each blanking die is rotated by 180°/(number of punching stations) for each press stroke, while the punch of each punching station is Since the blanking die is pressed down to the blanking state every press stroke number equal to the number of punching stations, the rotation angle at which each blanking die is rotated for every press stroke can be reduced. This reduces the influence of the means of rotating the blanking die when increasing the press speed.
A product laminated iron core, which is made by inverting the laminated core pieces one by one by 180 degrees and laminating and fixing them, can be manufactured with almost the same production efficiency as conventional product laminated iron cores.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a wide steel plate for a laminated iron core, FIG. 2 is a sectional view of a laminated iron core formed using one side of the iron plate shown in FIG. 1, and FIG. 3 is a sectional view of a laminated iron core according to the present invention. FIG. 4 is a plan view showing an embodiment of a mold device used in the iron core manufacturing method, showing the lower mold part; FIG. 4 is a cross-sectional view taken along line A-A in FIG. FIG. 5 is a perspective view showing the external appearance of a press device to which this invention is applied, centering on the index means in the above embodiment, and FIG.
The figure is a graph showing an example of the phase angle range in which the roller cam indexing device used in the indexing means operates for indexing in one stroke of the press slide. A plan view showing an example, FIG. 8 is an enlarged cross-sectional view showing a state where outline cutting and caulking are being performed by pressing down with a punch, and FIG. 9 is a laminated layer formed by the manufacturing method of the present invention. FIG. 10 is a cross-sectional view of the iron core, and a plan view showing an embodiment of a two-row progressive mold device. 1, 1', 1A, 1'A, 1B, 1'B...lower mold,
2, 3...Bearing, 4, 4A, 4'A, 4B,
4'B, 8... Sprocket, 5, 5'... Link chain, 6a, 6b... Groove, 7... Index means,
9...Roller cam index device, 10...Reduction device, 11...End of press crankshaft, 1
2, 14, 15, 17... Pulley, 13, 16... Belt, 18... Universal joint, 19... Bearing device, 20... Lower die device, 21... Upper die device, 22
...Slide, 23...Punch, 24, 24'...Cam, 25, 25'...Solenoid, 26...Cut and raised projection, 28...Strip, 30...Laminated iron core piece, 31
...cradle.

Claims (1)

[Claims] 1. A method for manufacturing a laminated iron core in which laminated iron core pieces of a predetermined shape are punched out of a strip-shaped iron core plate, and the laminated iron core pieces are successively laminated and fixed, wherein at least one pair of laminated iron core pieces are formed at point-symmetrical positions with respect to the center of the laminated iron core pieces. A plurality of punching stations for punching laminated iron core pieces having cut and raised protrusions for caulking from the band-shaped iron core plate are provided at a plurality of locations in the feeding direction of the band-shaped iron core plate, and the punching stations are arranged at each punching station so that the laminated iron core pieces having cut and raised protrusions for caulking are punched out at each punching station. Each blanking die that caulks the laminated iron core pieces is engaged with the indexing device and rotated by 180°/(number of punching stations) for each press stroke, and the punches of each punching station are rotated by the same number of presses as the number of punching stations. A method for manufacturing a laminated iron core, characterized in that the laminated iron core pieces are punched and caulked at a plurality of punching stations by pressing down into a punched state at each stroke number.