JPH0612936B2 - Method for manufacturing stator core for electric motor - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a stator core in a comparatively small induction motor, and more particularly to reversing a stack after punching an iron plate within the same punching plane. The present invention relates to a method for manufacturing a stator core for an electric motor.

[Background of the Invention]

In a relatively small capacity induction motor, it is common to form a stator core by laminating a predetermined number of ring-shaped stator iron plates punched from electromagnetic steel plates.

At this time, in order to improve the yield of the material and to enable continuous punching with a press machine, the outer shape of the stator iron plate 2 as shown in FIG. A method is widely used in which a substantially square shape is used, and a strip-shaped electromagnetic steel sheet 1 having a width W equal to the length of the side of the square is used as a raw material and continuously punched from the material. In FIG. 1, 3 is a bolt hole for assembling the electric motor, which is provided in the stator iron plate 2. Further, since the strip-shaped electromagnetic steel sheet 1 is supplied as a wound body, it is usually simply called a coil.

By the way, such a steel plate 1 necessarily has a plate thickness deviation in the rolling process along the width direction W thereof, and it can be said that it is impossible to avoid it in terms of cost.

On the other hand, the iron core of the electric motor is composed of a laminated body of the iron plates 2 punched from the steel plate 1 as described above, and the number of stacked sheets ranges from several tens to several hundreds.

As a result, when the iron plates 2 punched out as shown in FIG. 1 are laminated as they are to form an iron core, the above-mentioned plate thickness deviations are accumulated, and the dimension of the iron core in the stacking direction greatly differs between one side and the other side. There is a risk of becoming.

Therefore, as shown in FIG. 2, the iron plates 2 are stacked to form the iron core 4
When forming a sheet, half of the product thickness is turned upside down and stacked, so that the so-called inside-out reversal method is adopted so that the plate thickness deviation of the iron plate 2 is averaged and does not appear in the deviation of the iron core product thickness dimension. It was In FIG. 2, 4a represents a forward product part in which the iron plates 2 are stacked as it is, and 4b represents an inverted product part in which the iron plates 2 are turned upside down.

In recent years, so-called in-die lamination, in which the iron plates 2 punched from the steel plate 1 are laminated as they are in a female die for punching and integrated to continuously form an iron core, has become widely used. At this time, a so-called caulking integrated method has been mainly used in which caulking by the extrusion protrusions 5 as shown in FIG. 3 is used and the laminated iron plates 2 are alternately fixed.

The caulking state by the protrusion 5 will be described with reference to FIG.
Figure (a) is an enlarged cross section taken along the line A-A in Figure 3, and Figure 4 (b) is an enlarged cross section taken along the line BB in Figure 3, which is apparent from these figures. As described above, the protrusions 5 of the iron plate 2 stacked on top of each other are sequentially pushed into the cut portions that pushed out the protrusions 5 of the iron plate 2 on the lower side, and the fixation is performed.

However, as a result, when such in-die stacking is adopted, the above-mentioned inside-out reversal method cannot be applied, and the iron plate 2 is rotated 180 degrees as it is without turning it over so that the left and right sides are interchanged. There is no choice but to apply 180 degree inversion. The reason is that it is technically difficult to turn the iron plate 2 inside the mold, and if the steel plate 2 is turned inside-out, the crimping by the extrusion protrusions 5 becomes impossible at the turned-over portion.

On the other hand, applying such an in-plane 180 degree inversion causes another problem. That is, as is clear from FIGS. 1 to 4, in this type of iron core, three bolts are required for assembly.
This is often used, and therefore three bolt holes 3 are provided for that purpose. Therefore, when the in-plane 180 degree inversion is performed, as shown in FIG.
Then, the bolt holes 3 of the iron plate rotated 180 degrees do not match. In other words, at this time, in-plane 18
It is impossible to invert 0 degree. If the problem is simply the matching of bolt holes, as shown in Fig. 6,
It may be rotated 120 degrees in the plane. However, in this method, the width W direction of the strip-shaped steel plate 1 (first
The original effect of the reversal product, which is the offset of the thickness deviation existing in the figure), is considerably reduced, and, as is clear from FIG. 6, the outer peripheral shape of the iron plate 2 becomes uneven, and the position of the extrusion protrusion 5 does not match. This method is also practically impossible to employ, as it would result.

The reason why 3 is mainly adopted as the number of assembling bolts as described above is as follows. That is, most of these motors are three-phase induction motors,
Therefore, considering the balance between the phases of the magnetic circuit, it is desirable to set the number of assembled bolts to a multiple of three. However, considering the required strength and the like, it is not necessary to use six bolts, but only a factor of cost up is made. Therefore, when the performance of the electric motor is emphasized, generally three assembly bolts are used.

[Object of the Invention]

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a stator for an electric motor, in which caulking and unifying of an iron plate by in-plane inversion product is performed at the final stage of the punching process of the iron plate. It is an object of the present invention to provide a method for enabling in-plane 180 ° inversion in a method for manufacturing an iron core.

[Outline of Invention]

In order to achieve this object, the present invention provides a jig for laminating punched iron plates, which is installed in the lower part of a press female die used in the outer shape punching process of iron plates, and a driving means for rotating the jig by 180 degrees. By using and to perform in-plane lamination in this jig,
The feature is that an in-plane 180 ° inversion product is obtained.

Example of Invention

Hereinafter, a method for manufacturing a stator core for an electric motor according to the present invention will be described in detail with reference to the illustrated embodiments.

FIG. 7 shows an embodiment of the present invention. In the figure, S1, S2 and S3 represent punching stages of a press machine, and 6 and 7 are switching actuators.

In the manufacture of such an iron core, a so-called multi-stage pressing machine is used, and the strip-shaped steel plate 1 is sequentially transferred by a predetermined feed pitch P in the arrow A direction,
As a result, the steel plates 2 are passed through the female molds of the respective stages arranged in a straight line, and the necessary portions are sequentially pressed, and the iron plate 2 is obtained by pulling out at the last stage. And the stages S1 to S of FIG.
3 represents the stage of such a press, in particular stage S3 represents the last withdrawal stage.

The actuators 6 and 7 are composed of, for example, air cylinders, and have a function of enabling or disabling the male operation in each of the stages S1 and S2. That is, when the actuators 6 and 7 enable the male operation at that stage, the press working scheduled at that stage is performed in the operating cycle of the press machine.
For example, press working at the stage such as drilling is performed, but when the actuators 6, 7 disable the male die operation at that stage, there is no machining at that stage even in the operation cycle of the press machine. After the corresponding portion of the steel sheet 1 is stopped at that stage without being performed, the press working at that stage is sent to the next stage without performing anything.

Next, the operation will be described.

As described above, the strip-shaped steel plate 1 shown in FIG.
Has been pressed in several stages before reaching the stage S1, and the punching of the iron plate for the rotor of the electric motor and the processing of the slot for the winding have been completed.

Therefore, the stage S1 is provided with a press die capable of punching the bolt holes 3 and extruding the caulking projections 5 shown by the solid line in FIG. A bolt die 3 shown by a broken line in FIG. 5 and a press die for machining the caulking projection 5 which is the same as the stage S1 are installed.

Then, a press die for punching the outer diameter of the iron plate 2 is installed on the stage S3.

On the other hand, a jig 8 for stacking as shown in FIG. 8 is provided below the female die of the stage S3, and the iron plates 2 punched out by the outer diameter at the stage S3 are sequentially stored and stacked in the iron plate 2. I'm getting caught up in it.

In FIG. 8, 9 and 10 are bearings, 11 is a base, 12 is a toothed pulley, and the stacking jig 8 is rotatably held in the base 11 by the bearings 9 and 10, A belt (not shown) hung on the attached pulley 12 is configured to be rotatable as indicated by an arrow B in the figure.

Therefore, it is assumed that the actuators 6 and 7 are controlled to start the press machine operation so that the press work on the stage S1 is performed and the press work on the stage S2 is not performed.

Then, the steel plate 1 is pulled out as the iron plate 2 at the stage S3 without being processed at the stage S2, and is stacked in the jig 8. Therefore, at this time, the iron plate stacked in the jig 8 is the iron plate 2 having the bolt holes 3 shown in FIG.

Next, if the actuators 6 and 7 are controlled so that the processing on the stage S1 is stopped and the processing on the stage S2 is performed and the operation of the press machine is started, the stacking is performed in the jig 8 this time. The iron plate to be removed becomes the iron plate 2'having the bolt holes 3'shown in FIG.

Here, in FIG. 1, FIG. 3, and FIG. 7 and FIG. 7, the side end of the strip-shaped steel plate 1 is marked, and the right end is moved toward the transfer direction (direction of arrow A in FIG. 7) during press working. Assuming that R and the left end are L, they are as shown in FIGS. 9 and 10.

Therefore, by utilizing the stage S1 and operating the press machine with the stage S2 being killed, the iron plate 2 having the shape shown in FIG.
The operation of the pressing machine is continued until a predetermined number of sheets are stacked and stored in the jig 8, and the stacked iron plates 2 are dropped from the jig 8 as indicated by arrow C.

Next, the actuators 6 and 7 are controlled, this time the stage S1 is killed, the stage S2 is utilized, and the press machine is operated. Similarly, a predetermined number of iron plates are stacked and housed in the jig 8. However, since the iron plate 2'having the shape shown in FIG. 10 is stored in the jig 8 this time, the jig 8 is rotated 180 degrees by the belt, and then the iron plate 2'is stored therein. The laminated body of 2'is dropped as shown by an arrow C, and is stacked on the already laminated iron plate 2.

Then, as shown in FIG. 11, the iron core 4 is obtained by stacking the R end of the upper half and the L end of the lower half and reversing the product so that the thickness deviation is offset.

In this case, as shown in FIG. 5, there is no possibility that the bolt holes 3 are misaligned due to the inversion product, or the protrusions 5 and the outer diameters are not aligned as shown in FIG.

By the way, in the above description, the processing of the iron plates 2 and 2'by the stages S1 and S2 is continuously performed by half each of the number of laminated layers required for the iron core 4, and as shown in FIG. Although it is inverted in a lump of half the stack thickness, the actuators 6 and 7 are controlled so that the stages S1 and S2 are simultaneously utilized or killed, and the steel plate 1
The press work by the stages S1 and S2 is performed at the same time only once every two transfers of 1 pitch, and the jig 8 is rotated by 180 degrees each time punching is performed on the stage S3. By doing so, it is possible to obtain the iron core 4 in which the iron plates 2 and 2'are alternately inverted and stacked one by one.

Therefore, according to this embodiment, an in-plane 180 ° inversion product can be obtained by rotating the jig 8, and it is not necessary to rotate a press die such as a female die of the stage S3 to which a large force is applied, so that the configuration is simple. , You can get high precision easily.

Further, in the above embodiment, the two stages S1 and S2 are used for processing the iron plates 2 and 2 ', and the respective stages are independently performed. However, only one stage, for example, S1 is used, The female type and the male type may be simultaneously switched to those for the iron plate 2 and those for the iron plate 2 '. At this time, the female type can be made common by using one having holes corresponding to both the bolt holes 3 and 3 '.

Further, in the case of performing the inversion product for each group, it is needless to say that the inversion product is not limited to the inversion by the two groups as shown in FIG.

〔The invention's effect〕

As described above, according to the present invention, it is possible to average the product thickness deviation due to the inversion product even when the same inner lamination is performed, and the inversion product can be performed without disturbing the balance of the magnetic circuit, and at low cost. It is possible to easily provide a manufacturing method of a stator core that is useful for obtaining a high-performance electric motor.

[Brief description of drawings]

Fig. 1 is a plan view showing the shape of the material and the iron plate punched from it, Fig. 2 is a perspective view showing the appearance of the laminated core, Fig. 3 is a plan view of the in-die laminating iron plate, and Fig. 4 is caulking. FIGS. 5 and 6 are explanatory views of problems caused by in-plane inversion, and FIG. 7 is an explanatory view showing an embodiment of a method for manufacturing a stator core for an electric motor according to the present invention. FIG. 8 is a sectional view of the jig, FIG. 9 and FIG. 10 are explanatory views for understanding the operation of one embodiment of the present invention, and FIG. 11 is an illustration of an iron core according to one embodiment of the present invention. It is a perspective view. 1 ... band-shaped silicon steel plate, 2, 2 '... stator iron plate, 3, 3' ... bolt hole, 4 ... iron core, 5 ... caulking projection, 6, 7 ... actuator, 8: Stacking jig.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hironobu Takeda 7-1, 1-1 Higashi Narashino, Narashino City, Chiba Prefecture Hitachi Narashino Factory (72) Inventor Masayuki Sekiyama 7-1, Higashi Narashino, Narashino City, Chiba Prefecture Narashino Factory, Hitachi, Ltd. (56) References Japanese Unexamined Patent Publication No. 51-53204 (JP, A) No. 54-14302 (JP, U)

Claims (4)

[Claims] 1. A method for manufacturing a stator core for an electric motor, wherein the stator iron plate is crimped and integrated by in-plane inversion product in the outer die punching process of the iron plate. Direction and a control means for switching to different directions by 180 degrees in the same punching surface, and a jig for laminating punched iron plates installed at the lower part of the press female die used in the external punching process of the iron plates. A tool and a driving means for rotating the jig by 180 degrees are provided, and the in-plane inversion product of the punched iron plate is performed in the jig by the cooperative operation of the control means and the driving means. A method of manufacturing a stator core for an electric motor, comprising: 2. The electric motor according to claim 1, wherein the control means comprises a plurality of punching stages and a control device for operating only one of the plurality of punching stages. For manufacturing stator core for automobile. 3. An electric motor according to any one of claims 1 and 2, wherein the in-plane inversion product is alternately performed for each punched iron plate. Stator core manufacturing method. 4. An electric motor according to any one of claims 1 and 2, characterized in that the in-plane inversion product is configured to be performed in units of a group consisting of a plurality of iron plates. Stator core manufacturing method.