JPS6366407B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for punching magnetic iron plates, and in particular,
The present invention relates to a method for punching magnetic iron plates that is optimal for punching magnetic iron plates having a shape that has a notch when producing an iron core of an electromagnet or the like by laminating magnetic iron plates.

Conventionally, when punching a magnetic iron plate with a shape that has a notch, it is not possible to obtain the required precision by punching once due to the residual stress in the iron plate, so first, the precision is loosened with a rough punching die and the magnetic iron plate is roughened. After this rough punching, residual stress has been released by the rough punching, so finishing punching is performed using a finishing die to achieve exact precision, so-called double punching.

FIG. 1 shows an example of a conventional cutting die 1, and FIG. 2 shows a state in which a magnetic iron plate is punched using this cutting die 1. Punching is performed by placing the above-mentioned cutting die 1 on a long magnetic iron plate 2, and this process is performed continuously in the longitudinal direction to obtain a magnetic iron plate. Normally, each sheet is punched twice in order to remove residual stress caused by punching.

However, with conventional punching methods,
Since it is necessary to repeat the same operation twice, although the machining accuracy is improved, there is a drawback that the work efficiency is poor.

The present invention has been made in view of the above-mentioned points, and its object is to provide a method for punching out magnetic iron plates that can reduce the number of punches while maintaining processing accuracy.

The present invention focuses on the fact that the deformation that occurs when punching an iron plate is caused by residual stress in the iron plate, and in order to remove this residual stress, during one punching process of a magnetic iron plate, the punching process of the iron plate is performed. The position corresponding to the notch of the adjacent punched part, i.e. the punched iron plate (product)
A slit-shaped punching process is simultaneously performed to form a slit in a portion (magnetic iron plate) corresponding to the closed magnetic circuit portion of the magnetic circuit, so that a predetermined accuracy can be achieved with only one punching process.

The present invention will be described below based on embodiments shown in the drawings.

FIG. 3 schematically shows a punching die 11 used in the punching method of the present invention. As shown in the figure, the cutting die 11 in this embodiment has a cutting die surface 11b in the shape of a magnetic iron plate for an electromagnet having a notch 11C, and a slit-shaped cutting die surface 11a arranged in parallel with this. are doing. The slit-shaped cutting die surface 11a has a shape that almost fits inside the cutout 11C of the cutting die surface 11b, and the cutout 11C and the slit (cutting die surface 1
1a) is the distance between the two notches 1 of the punched iron plate.
It is the same as the mutual spacing L of 1C.

FIG. 4 and FIG. 5 are explanatory views of the punching method.

Using the cutting die 11 shown in Fig. 3, punch out a long magnetic iron plate (the shaded area in Fig. 4a and Fig. 5). , the first punched iron plate 100 (Fig. 4a
blank space) is punched out (the punched iron plate is
At this time, at the same time, the notch 100C (as shown in FIG.
No slits are formed in this area during the initial punching. ) A slit 100S is punched out at the punching position where the second steel plate is punched out, spaced by L from the second steel plate (indicated by a solid line in FIG. 4a). Next, in the same manner, the cutting die 11 is positioned so that the cutting die surface 11b is located at the position where the second steel plate is to be punched out (indicated by the dotted line in FIG. 4a), and the second sheet is punched out as shown in FIG. iron plate 20
0 (blank area in Figure 5) is punched out. At the same time, make a slit 20 at the notch position of the third iron plate.
0S is punched out. Thereafter, this operation is repeated one after another to sequentially form slits in the punched iron plate and the long magnetic iron plate. Of course, no slits remain in the punched iron plate, and slits remain in the long magnetic iron plates from which the second and subsequent punched iron plates are punched. 2
At the time when the first punched iron plate 200 is punched,
Residual stress is released due to the slit 100S punched out earlier. In other words, the magnetic iron plate is
The steel plate is rolled during manufacturing, and as a result, residual stress exists in the steel plate, but Slit 100S
By inserting a
Stress concentration occurs at both ends of the 0S (strain due to stress release at the slit is concentrated), but this part is not a problem as it has nothing to do with accuracy)). Therefore, there is no possibility of affecting the punching accuracy, and there is no need to punch twice as in the conventional method, and a predetermined accuracy can be obtained by punching only once. That is, as a means for releasing residual stress, the core punching die is provided with a function of slitting a notch in the shape of the core to be punched next.

According to the above-described method for punching a magnetic iron plate of the present invention, when the magnetic iron plate of a predetermined shape having a notch is punched once, the magnetic iron plate of the predetermined shape is punched out and adjacent to the punching process. At the same time, a slit-shaped punching process is performed in which a slit is formed at a position corresponding to the notch that forms a part of the magnetic circuit of the processed part, and this process is continuously repeated in the longitudinal direction of a long magnetic iron plate to form a magnetic iron plate. Since it is designed to be punched, it is possible to simultaneously process a magnetic iron plate with a predetermined shape with a notch and to create a slit at a position corresponding to the notch in the adjacent punched part, all in one punch. The processing accuracy can be achieved without punching twice to obtain a magnetic iron plate, and the required accuracy can be obtained by punching once, so work efficiency can be dramatically improved, especially when continuous production is required for mass production. It has a remarkable effect on punching.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram of a conventional punching die, Fig. 2 is a plan view showing the appearance of an iron plate after punching by the conventional punching method, and Fig. 3 is a schematic diagram of a punching die adopted in the method of the present invention. 4a is a diagram for explaining how the first magnetic iron plate is punched by the method of the present invention, and FIG. 4b is a schematic diagram of the magnetic iron plate punched by the method of the present invention. FIG. 5 is a diagram for explaining how a second magnetic iron plate is punched out by the punching method of the present invention. 11... Cutting die, 11a... Slit-shaped cutting die surface, 11b... Cutting die surface having the shape of a magnetic iron plate, 11C... Notch, 100, 200... Punching iron plate, 100C, C... Notch ,100S,2
00S...Slit.

Claims (1)

[Claims] 1. When obtaining a magnetic iron plate forming a laminated core having a notch, a method for punching a magnetic iron plate in which a long magnetic iron plate is continuously punched in the longitudinal direction using a cutting die, a predetermined shape having a notch is used. During one punching process of the magnetic iron plate, a slit is formed at a position corresponding to the notch part forming a part of the magnetic circuit in the punching part adjacent to the process of punching out the magnetic iron plate having a predetermined shape. A method for punching a magnetic iron plate, characterized in that a slit-like punching process is performed at the same time, and this process is continuously repeated in the longitudinal direction of a long magnetic iron plate to punch out the magnetic iron plate.