JPS6043743B2 - Manufacturing method of rotor with flywheel in internal rotating magnet type generator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a rotor with a flywheel in an internal rotary magnet type generator installed in a gasoline engine or the like.

A so-called internal rotating magnet type generator, which has a rotor that rotates inside the armature, has a small moment of inertia because the rotor cannot be made large due to its structure.If the engine specifications require a large moment of inertia, Generally, a flywheel is attached to the rotor, and especially when a flywheel is attached to a rotor that is integrally molded from a non-magnetic material such as aluminum, when it is integrally molded by die-casting etc. Instead of using a flywheel, the structure was such that the flywheel was fixed to the boss by screwing or caulking after the rotor was completed.

However, as mentioned above, when fixing the flywheel to the boss by tightening screws or culling, if the flywheel becomes large, the screws may loosen, shearing of the screws may occur, or the taper of the boss may occur due to caulking. There were drawbacks such as distortion occurring in the rotor and the rotor becoming more likely to fall off after being installed in the engine.

In order to solve the above-mentioned drawbacks, the present invention is based on forming the boss and the flywheel part integrally when the boss is a single unit, and then casting this with a non-magnetic material by die-casting or the like together with a magnet. This method improves the positioning method of the boss and magnet during casting. A through hole for supporting the magnet is provided in the flywheel section, and the support pin passed through this hole is inserted into the opposite side, that is, the anti-fly of the magnet. The boss and flywheel are integrated by holding the magnet with a support pin placed on the wheel side, and casting the magnet with a non-magnetic material while positioning the magnet in the axial direction relative to the boss. The object of the present invention is to provide a very useful manufacturing method that can improve the strength of the rotor and completely prevent distortion of the boss during manufacturing.

Embodiments of the invention shown in the drawings will be described below.

In FIGS. 1 and 2, reference numeral 1 denotes a cylindrical boss with a tapered hole that is keyed to the crankshaft of the engine, and a disc-shaped flywheel portion 1a is integrally formed at one end in the axial direction. There is a keyway lb and a screw l for pulling out the boss.
c is provided. A star-shaped magnet 2 is fitted into the boss 1 and has a plurality of radial magnetic pole parts 2a.

3 is a magnetic pole piece ring, which is made of a magnetic plate and extends radially from the magnetic pole piece ring.
It has the same number of magnetic pole pieces 3a.

The magnetic pole piece ring 3 is fitted into the stepped portion 1d of the boss 1 by press-fitting or welding, and each magnetic pole piece 3a is arranged at the tip of each magnetic pole portion 2a of the magnet 2. Reference numeral 4 denotes a non-magnetic material, such as a light alloy such as an aluminum alloy or resin, which surrounds the boss 1, magnet 2, and magnetic pole piece ring 3 and fixes these members together. Cast using a molding method such as an injection mold.

As shown in FIG. 3, the mold used in this molding means mainly consists of three molds 5, 6, and 7, and the details of the related structure between this mold and the above-mentioned parts will be supplementarily explained below. The mold has a first tapered support pin 5a in the first mold 5.
The second mold 6 is provided with a second cylindrical support pin 6a, the third mold 7 is provided with an appropriate number of third long cylindrical support pins 7a, and a tapered extraction pin 7b indicated by a broken line. .

On the other hand, a suitable number of three types of holes 8, 9, and 10 are provided in the flywheel portion 1a of the boss 1.

The hole 8 is a through hole through which the first support pin 5a passes,
One end has an inner diameter slightly larger than the maximum diameter (external diameter of the root part) of the support pin 5a, and the other end has a large diameter hole 8a that is sufficiently larger in diameter than the one end. This is because if the inner diameter of the hole 8 and the outer diameter of the support pin 5a are made almost the same, the non-magnetic material 4 will enter the gap between them like a burr, and this burr will easily peel off. Therefore, the hot water cycle of non-magnetic material 4.
The hole 8 is formed into a stepped hole as described above in order to improve the bonding strength and actively increase the strength of engagement between the non-magnetic material 4 and the flywheel portion 1a. Hole 9 is a through hole after all, and because the flywheel part 1a was added to boss 1, boss 1 rattled in the mold! In order to prevent molding defects,
This is for positioning the entire boss 1 with respect to the mold by inserting the second support pin 6a. Both through holes 8,
9 may be used as a reference hole for determining the relative positional relationship between the boss 1, the magnet 2, and the magnetic pole piece ring 3.
It has the advantage that it can also be used as a machining reference hole for drilling.

The remaining holes 10 are blind holes that open only inward, and are used to increase the strength of engagement between the non-magnetic material 4 and the flywheel portion 1a. On the other hand, the first support pin 5a and the third
The support pin 7a of the magnet 2 is brought into contact with both end surfaces of the magnet 2.
However, strictly speaking, these pins 5a and 7a do not necessarily have to come into contact with the end face of the magnet 2, and some axial clearance is allowed as shown in the figure.

Since the magnet 2 itself has large dimensional tolerances, it may be necessary to proactively provide this clearance in order to allow this tolerance. The tapered removal pin 7b is provided opposite to the first support pin 5a in order to balance the phenomenon of non-magnetic material 4 biting into the mold, and prevents the rotor from separating from the mold after molding. are doing.

In addition, in Fig. 1 and Fig. 2, 5a'', 77a''
, 7b'' are holes formed after removing the support pins 5a, 7a, 7b. In the above configuration, the boss 1 integrally provided with the flywheel portion 1a has a stepped portion 1d.
The magnetic pole piece ring 3 is fitted in advance, and the boss 1, the magnetic pole piece ring 3, and further the magnet 2 are arranged in the molds 5, 6, and 7 as shown in the third figure.

That is, the first holes 8 and 9 of the flywheel portion 1a are respectively
, insert the second support pins 5a and 6a, position the magnet 2 in the axial direction by sandwiching the magnet 2 between the first support pin 5a and the third support pin 7a, and remove the removal pin. 7b
is positioned between the magnetic pole parts 2a of the magnet 2. Next, the nonmagnetic material 4 is injected into the molds 5, 6, and 7 to obtain the finished product shown in FIGS. 1 and 2. In the above embodiment, the number of support pins 5a, 6a, 7a and the holes 8, 9, 10 in the flywheel portion 1a are selected as appropriate, and the number of holes 8, 9, 10 in the flywheel portion 1a is selected appropriately. The removal pin 7b can be omitted.

Further, the hole 8 may be a uniform hole with the inner diameter of the large diameter hole 8a, and instead of the magnetic pole piece ring 3, a single magnetic pole piece may be provided at the tip of each magnetic pole portion 2a of the magnet 2. As described above, in the present invention, the flywheel portion is integrally formed with the boss in advance, and the star-shaped magnet is positioned in the axial direction with respect to the boss by the support pins arranged on both sides of the flywheel portion. Since the flywheel is cast with a non-magnetic material, it is less likely that the flywheel will separate from the rotor during high-speed rotation, or that the flywheel will stick to the boss when installed. On the other hand, there are no accidents such as abnormalities such as distortion, and there is an excellent effect that a high-quality and high-performance rotor with a flywheel can be provided.

Furthermore, the axial positioning of the magnets can be determined by each support pin provided in the mold, and therefore it is necessary to prepare separate parts such as spacers for each rotor in order to position the magnets in the axial direction. This not only reduces the number of parts and assembly man-hours, but also allows the support pins provided on the mold placed on the flywheel side to position the magnets through the axial through-holes of the flywheel. Therefore, this support pin has the excellent effect of positioning the flywheel portion with respect to the mold and suppressing wobbling of the flywheel portion within the mold.

[Brief explanation of the drawing]

FIG. 1 is a front view showing an example of a rotor with a flywheel manufactured by the method of the present invention, FIG. 2 is a cross-sectional view taken along line A-A shown in FIG. 1 of the molds used
It is a sectional view showing an example. 1...Boss, 1a...Flywheel part, 2...Star-shaped magnet, 2a...Magnetic pole part,
4...Non-magnetic material, 5a, 7a...Support pin.

Claims (1)

[Claims] 1 A cylindrical flywheel part is integrally formed in advance at one end in the axial direction of the cylindrical boss, and a through hole in the axial direction is provided in the flywheel part, and the cylindrical flywheel part is fitted into the boss and has a radial magnetic pole part. A star-shaped magnet is provided with respect to the boss through a support pin provided on a mold disposed on a side of the flywheel portion of the magnet through the through hole, and a support pin provided on a mold disposed on a side of the magnet opposite to the flywheel portion. A method for manufacturing a rotor with a flywheel for an internally rotating magnetic generator, characterized in that the rotor is cast with a non-magnetic material while being positioned in the axial direction by a support pin.