JPS645977Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a flywheel magnet rotor used in a magnet generator attached to an internal combustion engine or the like.

BACKGROUND ART A flywheel magnet rotor is used as a rotor for a magnet generator attached to an internally twisted engine, etc., in which a permanent magnet is attached to the inner periphery of a substantially cup-shaped flywheel by adhesive. In this case, since fragile ferrite magnets are used as permanent magnets, if an object hits the magnets when the rotor is installed in an engine or the like, the magnets may break. Therefore, the fourth
As shown in Figure A, an end surface 3a of a permanent magnet 3 fixed to the inner circumference of the flywheel 1 with adhesive 2
It has been proposed that a protective film 4 is formed by applying an adhesive to the surface. However, in this magnet rotor, the thickness of the protective film 4 becomes thinner near the corners 3b of the magnets 3, so the corners of the magnets 3 cannot be sufficiently protected.
If something hits the corner of the magnet 3, there is a risk that the magnet will break. Furthermore, when the thickness of the protective film 4 is increased,
The protective film 4 sometimes cracked due to the difference in thermal expansion coefficient between the magnet and the adhesive, and the protective film 4 sometimes fell off.

In addition, as shown in FIG. 4B, the end surface 3 of the magnet 3
A non-magnetic metal annular protective cover 5 covering the inner peripheral surface 3c is placed over the magnet 3, and an annular spacer 6 is placed on the end surface of this protective cover.
A flywheel magnet rotor is known in which a protective cover 5 is fixed via a spacer 6 by a seaming portion 7 that is applied over the entire circumference of the end portion of the peripheral wall portion 1a. In this magnet rotor, the magnets 3 are completely covered by the metal protective cover 5, so
Although the magnet 3 can be completely protected, if the inner circumference of the magnet 3 is covered with the protective cover in this way, the effective air gap between the magnet 3 and the magnetic poles of the stator (not shown) is covered by the protective cover 5. Since the thickness increased by the amount of thickness, there was a drawback that the output of the generator decreased. Furthermore, this magnetic rotor has disadvantages in that the protective case is large, so a large amount of non-magnetic metal is used, and the cost is high due to the large number of parts and the number of processing steps.

Purpose of the invention The purpose of the invention is to provide a flywheel magnet rotor that sufficiently protects the magnets, does not increase the air gap between it and the stator, and reduces manufacturing costs. Our goal is to provide the following.

Structure of the invention In the present invention, an annular protection plate is provided to cover the end face of a permanent magnet that is adhered to the inner periphery of a flywheel formed in a substantially cup shape, and this protection plate is fitted onto the inner periphery of the flywheel. and adhere it to the end face of the permanent magnet. The protection plate has an inner diameter approximately equal to the inner diameter of the permanent magnet, and a portion of the protection plate closer to the inner circumference is formed to form an annular groove that opens toward the end surface of the permanent magnet. .

With this configuration, the magnet can be protected by simply using a small protective plate that covers the end face of the permanent magnet, and the protective plate simply fits into the inner circumference of the flywheel and adheres to the end face of the magnet. Since it can be installed at any time, there will be no increase in cost.
The excess adhesive generated when bonding the protective plate to the end face of the magnet is stored in the space between the annular groove formed near the inner circumference of the protective plate and the end face of the magnet, so that It is possible to prevent the adhesive from flowing down onto the inner peripheral surface. Furthermore, since the inner portion of the protective plate is formed to form an annular groove, the inner portion of the protective plate that covers the corner of the magnet has elasticity to buffer external forces. This allows the corners of the magnet to be sufficiently protected.

Embodiments Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 to 3.

1 and 2 show an embodiment of the present invention, and in these figures, reference numeral 10 indicates a cup-shaped flywheel. A hole 10b is formed in the center of the bottom wall 10a of the flywheel 10, and a boss 11 for attaching a rotating shaft is fitted into this hole. The boss 11 has a flange 11a at one end, and this flange 11a is fixed to the flywheel 10 by a rivet 12. Boss 11
can also be formed integrally with the flywheel. A plurality of arc-shaped permanent magnets 13 are arranged in a ring shape on the inner periphery of the peripheral wall 10c of the flywheel 10. These magnets are positioned in the axial direction of the flywheel 10 by protrusions 10d formed on the peripheral wall 10c at appropriate intervals, and are fixed to the peripheral wall 10c with an adhesive 14. Predetermined regions of the permanent magnets 13, 13, . . . are magnetized in the radial direction so that magnetic poles of different polarities are alternately arranged in the circumferential direction of the rotor. An annular protection plate 15 made of non-magnetic metal such as aluminum, weakly magnetic metal such as stainless steel, plastic, etc. is fitted on the inner periphery of the peripheral wall 10c of the flywheel near the open end to protect the end surface of the permanent magnet 13. is glued to. The inner diameter of the protection plate 15 is set approximately equal to the inner diameter of the permanent magnet arranged in a ring shape, and the inner diameter portion of the protection plate 15 has an opening of the flywheel 10, as shown in FIG. 3A. The permanent magnets 13, 13, . . . are formed into a shape having a substantially semicircular cross section so as to form an annular groove 15a opening toward the end surface 13a of the permanent magnets 13, 13, . Further, a portion of the protection plate 15 closer to the outer periphery than the annular groove 15a is formed into a flat plate shape, and this flat plate portion 15b is bonded to the end surface 13a of the permanent magnets 13, 13, .
The outer diameter of the protection plate 15 is set to be slightly larger than the inner diameter of the flywheel 10, and the protection plate 15 is lightly press-fitted into the peripheral wall of the flywheel.

In manufacturing the flywheel magnet rotor of the above embodiment, in order to attach a permanent magnet and a protection plate to the flywheel, first, the peripheral wall 1 of the flywheel 10 is
Adhesive 14 is applied to the inner periphery of 0c, and permanent magnets 13, 13, . . . are pressed against the inner periphery of the peripheral wall and fixed. At this time, the excess adhesive is attached to the permanent magnets 13 and 1.
It is extruded onto the end surface 13a of 3, . Next, the protection plate 15 is lightly press-fitted into the inner circumference of the flywheel 10, and this protection plate is attached to the permanent magnet 13,
13,... is pressed against the end surface 13a. At this time, the excess adhesive tends to flow toward the inner circumferential side of the permanent magnet 13, but this excess adhesive flows into the annular groove 1 of the protection plate 15.
Since it is accommodated in the space formed between 5a and the end surface of the permanent magnet 13, it does not flow out onto the inner circumferential surface of the permanent magnet. After the protective plate 15 is disposed in this manner, the entire assembly is placed in a heating furnace and heated to heat and harden the adhesive 14, thereby completing the flywheel magnet rotor.

If the protective plate 15 is fitted to the inner circumference of the flywheel by light press-fitting as in the above embodiment, each part can be temporarily fixed in place without using a jig until the adhesive hardens. Although the workability can be improved, the present invention is not limited to the case where the protection plate 15 is press-fitted to the inner periphery of the flywheel in this way, but it is also possible to fit the protection plate 15 loosely into the inner periphery of the flywheel. The present invention also includes the case of temporary fixing using a jig.

Further, as the protection plate 15, for example, as shown in FIG. 3B, one having a peripheral wall portion 15c on the outer circumference side that fits into the inner circumference of the flywheel may be used. When the peripheral wall portion 15c is provided on the outer periphery of the protection plate in this manner, the elasticity of the peripheral wall portion can be used to smoothly press fit the protection plate into the inner periphery of the flywheel.

In the above embodiment, the permanent magnets are arranged in a ring shape around the inner circumference of the flywheel, but in some cases, multiple arc-shaped permanent magnets may be installed at intervals in the circumferential direction, or a single ring-shaped permanent magnet may be installed. The present invention can also be applied when fitting onto the inner periphery of a flywheel.

The flywheel magnet rotor described above is attached to the engine by fitting the boss portion 11 onto the crankshaft of the internally twisted engine, for example. A stator with a power generation coil wound around an armature core is arranged inside the flywheel magnet rotor, and this stator is fixed to a base plate provided on the engine case or cover, etc. and a stator constitute a magnet generator.

Effects of the invention As described above, according to the invention, the magnet can be protected by simply using a small protection plate that covers the end face of the permanent magnet, and the protection plate fits into the inner circumference of the flywheel. Since the flywheel magnet rotor can be attached by simply gluing it to the end face of the magnet, it is possible to obtain a flywheel magnet rotor that prevents damage to the permanent magnets without increasing costs. Furthermore, since the inner circumferential surface of the permanent magnet is not covered with a protective plate, the effective air gap with the stator magnetic poles can be reduced, and the output of the generator can be increased. In addition, an annular groove that opens on the end face of the permanent magnet is provided on the inner circumference of the protective plate to form a cavity for storing excess adhesive, so that the adhesive flows out onto the inner circumference of the magnet and It is possible to prevent the inner circumferential surface from being soiled by the adhesive. Furthermore, since external force can be buffered by the annular groove-formed portion of the protection plate, the inner peripheral corner of the magnet, which is most likely to be damaged, can be effectively protected.

[Brief explanation of the drawing]

Figures 1 and 2 show an embodiment of the present invention, with Figure 1 being a front view before the protection plate is attached, Figure 2 being a longitudinal sectional view with the protection plate attached, Figures 3A and 3B are perspective views showing parts of different examples of the protective plate used in the present invention, and Figure 4A
and B are sectional views showing essential parts of different conventional examples. 10...Flywheel, 13...Permanent magnet,
13a... End face of a permanent magnet located on the open end side of the flywheel, 14... Adhesive, 15... Protective plate, 15a... Annular groove.

Claims (1)

[Scope of utility model registration request] In a flywheel magnet rotor in which permanent magnets are bonded to the inner periphery of a flywheel formed in a substantially cup shape, an annular protection plate that covers an end surface of the permanent magnet located on the open end side of the flywheel is provided. The protection plate is fitted onto the inner periphery of the flywheel and bonded to the end face of the permanent magnet, and the protection plate has an inner diameter approximately equal to the inner diameter of the permanent magnet, and a portion of the protection plate closer to the inner periphery is attached to the permanent magnet. A flywheel magnet rotor characterized in that the rotor is shaped to form an annular groove opening on the end face side of the magnet.