JPH0117339B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a method for manufacturing a flywheel used in a rotor of a magnet generator installed in an internal combustion engine, etc., and particularly relates to a method for manufacturing a flywheel used in a rotor of a magnet generator installed in an internal combustion engine, etc., and particularly for small-sized internal combustion engines such as agricultural machinery. The present invention relates to a method for manufacturing a flywheel used in a magnet rotor suitable for installation in an engine.

[Prior art]

2. Description of the Related Art In small-sized internal combustion engines for use in agricultural machinery, etc., it is necessary to reduce the weight of a magnet generator mounted thereon by making the magnet generator smaller. In response to this request, conventionally,
This was addressed by reducing the shape and dimensions of the existing magnet generator. However, there is a limit to the miniaturization and weight reduction of existing magnet generators, and miniaturization also has the disadvantage of increasing costs due to poor assembly workability. Therefore, in order to solve these drawbacks, the present applicant first formed a flywheel into a substantially disk shape, provided a notch on the outer periphery of the flywheel, and permanently installed a magnet mounting pedestal provided in the notch. We are proposing a flywheel magnet rotor that has fixed magnets and is smaller and lighter.

1 and 2 show an embodiment of a flywheel magnet rotor previously proposed by the present applicant. In this embodiment, the flywheel magnet rotor 1 is a circular ring made of magnetic metal such as iron. It is equipped with a plate-shaped flywheel 2. A tapered rotary shaft fitting hole 3 having a keyway 3a is formed in the center of the flywheel 2. A boss portion 4 is integrally formed around the opening end of the rotary shaft fitting hole 3 by bulging a portion of the thick portion of the flywheel outward. A U-shaped notch 5 is formed on the outer periphery of the flywheel 2, and a magnet fixing pedestal 6 is integrally formed at the bottom 5a of the notch 5 (the part on the rotating shaft fitting hole 3 side). ing. The pedestal portion 6 has a magnet fixing surface 6a oriented perpendicularly to the plate surface of the flywheel 2, and a permanent magnet 7 magnetized in the radial direction of the flywheel is arranged on this magnet fixing surface. A magnetic pole piece 8 is disposed on the end surface of the permanent magnet 7 opposite to the fixed surface 6a, and the magnet 7 is attached to the base portion 6.
Furthermore, the magnetic pole pieces 8 are each fixed to the magnet 7 by suitable means such as adhesive or screw fixing. In addition, when these are fixed by screws, both are fixed to the pedestal part at the same time by screws penetrating the magnetic pole piece 8 and the magnet 7. With the magnet 7 and the magnetic pole piece 8 fixed to the pedestal 6 in this manner, the outer surface of the magnetic pole piece 8 is positioned on the cylindrical surface that is substantially the same as the outer peripheral surface of the flywheel 2, and the magnetic pole piece 8 and the flywheel outer peripheral surface 2a on both sides of the notch 5 constitute rotor magnetic poles. The reference numeral 9 indicated by a dashed line is a stator consisting of a U-shaped iron core 9a and a power generating coil 9b wound around the iron core.

In processing the magnet fixing pedestal 6 of the flywheel 2, a steel plate is punched out into a substantially disc shape, and two notched recesses are formed to form a tongue piece 2'' in a part of the material. Attempts have been made to form a tongue piece 2' by sandwiching it between gripping dies 10A and 10B as shown in FIG. 3, and compressing the tongue part 2'' with a punch 11.

[Problem to be solved by the invention]

However, in order to form the magnet fixing pedestal by compressing the tongue, it is necessary to increase the force required to compress the tongue, which has the drawback of increasing the size of the press machine. Furthermore, when compression processing is applied to the tongue portion 2'', the flow of material in the tongue portion becomes uneven due to buckling, etc., and as shown in Fig. 4a, the pedestal portion 6 protrudes from the plate surface of the material. The overhanging parts 6a and 6b have unequal lengths, and the magnet fixed to the pedestal part cannot be placed at a predetermined position relative to the stator 9 as a generator, resulting in a decrease in performance. It was hot.
Furthermore, when the tongue piece 2'' is compressed to form the pedestal part 6, the planar shape of the pedestal part 6 becomes an oval shape as shown in FIG. 4b. It had the disadvantage that only a small magnet could be attached to it despite its large area.Also, in order to make the area of the pedestal sufficiently large, only the tongue part was enlarged and this tongue part was compressed. Even if this was done, buckling occurred in the tongue portion, making it impossible to form the desired pedestal portion.Furthermore, in order to solve the above-mentioned drawback, predetermined pedestal portions were attached to the dies 12A and 12B as shown in FIG. Molding surface 13A, 1
3B and by upsetting the tongue portion 2'', it is possible to make the projecting portions of the pedestal portion 6 the same length or to make the planar shape of the pedestal portion 6 rectangular.
In this case, the size of the press machine was unavoidable, the die became complicated, and the molding surface of the die was severely worn, which shortened the life of the die.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for manufacturing a flywheel for a magnet rotor, which eliminates the problems of the conventional methods described above.

[Means to solve the problem]

In view of the above-mentioned drawbacks, the present invention provides a pedestal for fixing a magnet by dividing the tongue into two parts in the thickness direction without compressing the tongue part, and then bending each of the two divided tongue parts. form a section.

〔Example〕

The manufacturing method of the present invention will be explained in detail below with reference to the drawings.

6 to 8 are explanatory diagrams for explaining the manufacturing method of the present invention. FIG. 6 is a front view showing a material formed by punching a magnetic metal plate such as an iron plate, and FIG. 7 is a pedestal part forming process. It is a process explanatory drawing which shows the 1st process.
In these figures, 20 is a blank or material formed by punching a magnetic metal plate such as an iron plate.
Two notch recesses 21, 21 are formed, and a tongue piece portion 22 is formed between these notch recesses. In the method of the present invention, as shown in FIG. 7, this material 20 is gripped with dies 23A, 23B with the tongue portion 22 protruding upward from the dies 23A, 23B, and a wedge-shaped punch 24 is used to grip the tongue portion 22. Divide 22 into two in the thickness direction. This operation is the first step of the pedestal part forming process. Next, as shown in FIG. 8, the material 2 held by the gripping dies 23A, 23B
The second step of the pedestal forming step is performed in which the tongue portions 22', 22' divided into two parts of 0 are bent by the punch 25 to project the projecting portions 26A, 26B at right angles from the plate surface of the material 20. The magnet fixing pedestal 27 formed in this way is formed by bending the material without being crushed.
The projecting lengths of the projecting portions 26A and 26B projecting perpendicularly from the plate surface can be made equal, and the planar shape of the magnet fixing pedestal can be made substantially rectangular.

In the above manufacturing method, the material 20 is held by the same gripping dies 23A, 23B in both the first step and the second step in the pedestal forming step. It is also possible to use different gripping dies for holding the material 20 during the process. If it is necessary to enlarge the magnet fixing pedestal, the tongue portion may be enlarged in advance as shown by the two-dot chain line in FIG. 6 when punching out the iron plate. In this case, the tongue part is bent, so
Buckling does not occur as with conventional compression processing. Furthermore, when molding the material 20, the notch recesses (two locations) may not be formed at the same time as punching out the disk-shaped portion, but first a disk may be punched out from the material, and then the notch recesses may be formed.

〔Effect of the invention〕

As described above, according to the present invention, the pedestal part forming process includes the first process of dividing the tongue part into two in the thickness direction;
The second step is bending each of the divided tongue portions so as to overhang both sides in the thickness direction of the material, so that the overhang length of the overhang of the pedestal portion that overhangs from the plate surface of the material can be reduced. The heights of the base portions can be made equal, and the planar shape of the pedestal portion can be formed into a substantially rectangular shape. Therefore, a large magnet can be fixed by effectively utilizing the surface of the magnet fixing pedestal, and the positioning accuracy of the magnet with respect to the stator can be improved. In addition, the pedestal part is not formed by compression processing as in the past, but the tongue part is 2 parts in the thickness direction.
Forming is done by dividing the press into parts and bending each tongue into two, so the pressure load from the press machine can be reduced, and punches, dies, etc. can be used for low loads, and the press machine can be made smaller. This has the advantage of reducing equipment costs.

[Brief explanation of drawings]

Fig. 1 is a front view of a flywheel magnet rotor to which the manufacturing method of the present invention is applied, Fig. 2 is a sectional view taken along the - line in Fig. 1, and Figs. 3 and 5 are main points of the conventional manufacturing process. Part process explanatory diagram, Figure 4 a and b
6 is a longitudinal cross-sectional view and a plan view showing a magnet fixing pedestal formed by a conventional manufacturing method, respectively. FIG. 6 is a front view showing a punched material formed by punching a magnetic metal plate. FIG. FIG. 2 is a process explanatory diagram showing the first step of the manufacturing method of the invention. FIG. 8 is a process explanatory diagram showing the second step of the manufacturing method of the present invention. 2...Flywheel, 6, 27...Pedestal for fixing magnet, 20...Material, 21...Notch recess, 2
2, 22'...Tang piece part, 23A, 23B...Grabbing die, 24, 25...Punch, 26A, 26B
...Overhang.

Claims (1)

[Claims] 1. A material forming step in which a magnetic metal plate is punched out to form a substantially disc-shaped material, and two notch recesses are formed in a part of the material to form a tongue portion; A pedestal forming step in which a magnet fixing pedestal is formed by forming the material so as to protrude perpendicularly to the plate surface of the material, and a fitting hole forming step in which a rotary shaft fitting hole is formed in the material. In the method for manufacturing a flywheel for a magnet rotor, the pedestal portion forming step includes a first step of dividing the tongue portion into two in the thickness direction, and dividing the tongue into two in the first step. A method for manufacturing a flywheel for a magnet rotor, comprising: a second step of bending each of the tongue pieces so as to protrude on both sides in the thickness direction of the material.