JPS62163548A - Rotor for magneto generator - Google Patents

Abstract

PURPOSE:To simply prevent a high speed rotating region from swelling or deforming by forming a groove on the opening end of a yoke. CONSTITUTION:The rotor of a flywheel magnet has a yoke 11 in conjunction with a flywheel, a plurality of magnets 12 arranged on the inner periphery of the yoke 11, a case 13 for fixedly positioning the magnets 12, a cover 14 for protecting the magnets 12, and a retainer ring 15. A winding calking margin 19 is formed on the upper end of the yoke 11 by cutting the outer periphery, and groove 20 of approximately semicircular section is formed on the root of the margin 19 in a series of annular state. The groove 20 suppresses the outward swelling or deformation at the yoke opening due to a centrifugal force.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a rotor for a magnet generator, and particularly relates to an improvement in a type in which the rotor is also used as a flywheel.
For example, the present invention relates to a rotor of a flywheel magnet used in a relatively high-speed rotation region such as a small vehicle such as a motorcycle or a special vehicle such as a racing car or buggy.

[Conventional technology]

As a conventional flywheel magneto, a rotor, in which a plurality of magnets are arranged and fixed in an annular manner on the inner circumferential surface of a yoke formed in a substantially bottomed cylindrical shape, is arranged at the generator station. Some generators are configured so that the rotor is driven by the engine and rotates around the generator, thereby inducing an electromotive force in each magnetic pole coil of the generator.

[Problem that the invention seeks to solve]

In the rotor of such a flywheel magneto, the yoke receives the resultant force of the centrifugal force due to its own weight and the centrifugal force due to the weight of the magnet during rotation, but the bottomed side of the yoke is affected by the bottom wall. While the yoke is supported to ensure sufficient centrifugal strength, the open end of the yoke is unsupported, and as the rotation speed increases, the yoke bulges outward due to centrifugal force and becomes more deformed than the bottomed end. The inventor of the present invention has discovered that there is a problem.

An object of the present invention is to provide a rotor for a magnet generator that can prevent bulging deformation in a high-speed rotation region without requiring major modification.

[Means for solving problems]

The rotor of the magnet generator according to the present invention is characterized in that grooves are recessed in the open end surface of the yoke.

[Effect]

The groove recessed in the open end surface of the yoke reduces the weight of the open end of the yoke and increases the surface area of the open end surface, thereby effectively dispersing centrifugal force. By forming a hollow part that is not directly affected, it is thought that the yoke exerts effects such as increasing the resistance to the outward bulging deformation, and these effects and the synergistic effect of these effects reduce the resistance to centrifugal force. The outward bulging deformation of the yoke opening is effectively suppressed.

〔Example〕

Fig. 1 is a longitudinal cross-sectional view showing a rotor of a flywheel magneto according to an embodiment of the present invention, Fig. 2 is a partially omitted partially cutaway plan view, and Fig. 3 is an enlarged portion of the section ■ in Fig. 1. Cross-sectional view, Fig. 4 fal [bl (cl and Fig. 5 fatfbl
(cl is each bulging deformation degree diagram showing the rotation test results for explaining the effect, and FIG. 6 is a radius change amount diagram as well.

In this embodiment, the rotor of the flywheel magneto includes a yoke 11 that also serves as a flywheel, a plurality of magnets 12 arranged on the inner circumference of the yoke 11, and a case 13 for positioning and fixing the magnets 12. It includes a cover 14 for protecting the magnet 12 and a holding ring 15.

The yoke 11 is integrally formed into a substantially cylindrical shape with an open top and a closed bottom by a suitable means such as forging using a magnetic material such as structural steel. At the center is a shaft hole 16 for inserting a boss (not shown) directly connected to the rotor, and a plurality of holes 17 are drilled at outer positions of the shaft hole 16 for connecting the rotor to the boss. has been done. For mounting, a plurality of protrusions 18 for preventing rotation of the case 13 are provided at positions outside the hole 17 by pushing up the lower closing wall from the outside. are arranged circumferentially at arbitrary angles. A winding caulking margin 19 is formed at the upper end of the yoke 11 by cutting the outer periphery, and the upper end surface of the yoke 11 has a substantially semicircular cross section. l
520 is disposed at the base of the winding and caulking portion 19 and is recessed in a series of annular shapes. The width and depth of the groove 20 are the same as those of the yoke 1.
The thickness is set to about 1/3 of the thickness of the cylinder wall portion of No. 1.

The magnet 12 has a height less than or equal to the depth of the yoke 11,
It is integrally molded into a substantially rectangular parallelepiped having an arcuate shape curved along the inner periphery of the yoke 11 in the width direction.

The case 13 is integrally molded using a non-magnetic material having appropriate elasticity, such as resin, and has a generally cylindrical shape that fits inside the yoke 11 as a whole. A plurality of storage chambers 31 are formed in the cylindrical wall 30 of the case 13 and arranged in the circumferential direction with substantially equal phase differences.

The storage chamber 31 has a height less than or equal to the height of the magnet 12,
It is formed in a hollow chamber having a width slightly larger than the width of the magnet 12, and the hollow portions of the ceiling wall, rear wall, and abdominal wall are open. The floor wall portions 32 of each storage chamber 31 are adjacent to each other to form a series of rings 33 . A plurality of recesses 34 are sunk in the lower surface of the ring 33, and each recess 34 is formed to fit into the projection 18 of the yoke 11. Adjacent containment room 3
1.31, a partition wall portion 35 is formed to stand up in a columnar shape, and a holding portion 3 is formed on the partition wall portion 35.
6 are disposed on both sides in the circumferential direction, and are formed to protrude in a substantially tangential direction (perpendicular direction to the normal line passing through the circumferential center of the partition wall portion).

The cover 14 is integrally formed by drawing press using a magnetic metal material such as a thin iron plate, and has a generally cylindrical shape that fits inside the case 13 as a whole. The presser ring 15 is integrally molded using the same material as the case 13 and has a substantially same circular ring shape as the case 13.

Then, the case 13 is fitted into the yoke 11, and the concave portions 34 on the lower surface of the case 13 are fitted into the convex portions 18 raised on the bottom wall of the yoke 11, respectively. By fitting the convex portion 18 and the concave portion 34, the case 13 is prevented from rotating integrally with the yoke 11.

Subsequently, the magnets 12 are press-fitted into each housing chamber 31 of the case 13 from above. When the magnet 12 is strongly pushed into the storage chamber 31, the presser portion 36 protruding from the side surface of the partition wall portion 35 is pressed so strongly that it is crushed by the side surface of the magnet 12, as shown in FIG. Pressed. In this crushed state, the holding part 36 is compressed and deformed by the magnet 7) 12 and is strongly resilient. They will be pushed together.

Thereafter, a cylindrical shape having an outer diameter approximately equal to the diameter of the circular inner circumferential surface of the 12 groups of magnets is formed inside the 12 groups of magnets that are housed and fixed in each housing chamber 31 of the case 13 and arranged in an annular shape. The cover 14 is press-fitted. Next, the cover 1 covering the upper end surface of the case 13
A presser ring 15 is placed on the upper flange of the yoke 11, and a winding caulking process is applied to the winding caulking margin 19 at the upper end of the yoke 11 to push it inward. This results in
Yoke 11, magnet 12, case 13, cover 14
The holding ring 15 is then crimped and integrated. That is, in this rotor, each magnet 12 is accommodated in each accommodation chamber 31 in the case 13 fitted into the yoke 11 and positioned on the inner circumference of the yoke 11, and the holding part 36 is located between the partition parts 35 and 35. It is clamped and fixed by.

Next, the effect will be explained.

When the rotor is rotated at high speed, the yoke 11 receives a resultant force of the centrifugal force due to its own weight and the centrifugal force due to the weight of the magnet 12. As a result, the cylindrical wall of the yoke 11 is locally subjected to a strong centrifugal force at the position where the magnet is arranged, and therefore tends to bulge outward at that position. Incidentally, the centrifugal force due to ff1l of the case is sufficiently smaller than that of the magnet 12.

At this time, the lower part of the cylindrical wall of the yoke (the part on the closed wall side) is increased in rigidity because the closed wall acts like a lip.
Sufficient centrifugal force resistance is ensured.

As a result, local bulging deformation of the lower portion of the cylindrical wall portion of the yoke is prevented.

On the other hand, the upper part (opening side part) of the cylinder wall of the yoke
Since it is open, its centrifugal strength is weaker than that of the lower part.

As a result, when the upper part of the cylindrical wall of the yoke is locally strongly subjected to centrifugal force at the position where the magnet is disposed, it bulges outward and deforms.

In other words, the cylindrical wall of the yoke bulges outward in the vicinity of its opening, as shown by the imaginary line in FIG. The peak is at the center of the magnet in the circumferential direction, as shown in FIG. The amount of deformation is approximately proportional to the rotation speed of the rotor.

However, like the rotor according to the above configuration, the yoke 1
Research by the present inventors has revealed that when 'tR20 is recessed in the upper end surface of No. 1, bulging deformation is suppressed compared to when no groove is recessed.

FIGS. 4 and 5 show a rotor according to this embodiment and a rotor without grooves in the yoke (hereinafter referred to as a conventional rotor).
and are each line diagram proportionally showing the bulge deformation when rotated at high speed under the same conditions, and both figures f
al (bl (cl has a rotational speed of 2400 Orpm,
The cases of 26,000 rpm and 28,000 rpm are shown, respectively. By the way, in Figures 3 and 4,
Each peak portion of the bulging deformation approximately corresponds to a position where the magnet is placed.

FIG. 5 is a diagram showing the relationship between the rotational speed (horizontal axis) and the amount of change in radius at the bulging deformation peak location (!1 axis). B shows the case of a conventional rotor.

As is clear from the comparison between FIG. 3 and FIG. 4, and the comparison between curves A and B in FIG. be done. This is considered to be due to the following effects of the grooves and their synergistic effects.

The groove reduces the weight of the open end of the yoke.
It relieves that centrifugal force. The groove increases the surface area of the upper end surface of the yoke, thereby dispersing the centrifugal force that acts strongly locally at the opening over the whole. By forming a hollow part in the opening of the yoke, the groove forms a space that is not directly subjected to centrifugal force, thereby canceling out the tensile force and compressive force that act during bulging deformation. The groove increases the overall moment of inertia and section modulus at the yoke opening.

According to this embodiment, by recessing the grooves in the opening end face of the yoke, it is possible to suppress outward bulging deformation of the yoke opening during high-speed rotation, thereby increasing the rotor's high-speed rotation resistance. can be improved and its safety can be increased.

In other words, repeated bulging deformation of the yoke due to high-speed rotation means an increased risk of metal fatigue, but if bulging deformation is suppressed and the high-speed rotation region where it occurs becomes higher, The risk of fatigue is significantly reduced.

In this way the rotor's high speed mouth! By enabling use in the 2-region, the performance of flywheel magnetos can be significantly improved.

Moreover, in this embodiment, it is only necessary to recess the groove in the opening end face of the yoke, so it is extremely economical, easy to mate with the generator, and has great practicality. In other words, as a structure to increase the rotation resistance of the yoke opening, it is generally considered that a flange is provided at the yoke opening, but this structure complicates the machining and also ensures rotational balance. This makes it difficult and uneconomical, and it also reduces compatibility with the generator, making it impractical.

Note that the present invention is not limited to the above embodiments,
It goes without saying that various changes can be made without departing from the gist of the invention.

For example, the grooves may not necessarily be formed in a series of annular shapes, but may be formed intermittently.

The cross-sectional shape of the groove is not limited to a semicircle, but may be U-shaped or the like.

The grooves are not limited to being formed by plastic working such as cold or hot forging, but may also be formed by cutting or the like.

The width, depth, shape, continuity, discontinuity, number of grooves, etc. of the grooves are determined by appropriate means such as experiments and computer analysis.
It is desirable to find the optimum value according to various conditions such as usage, maximum rotation speed, yoke diameter, wall thickness, magnet size, weight, etc.

Further, the specific structure such as the structure for fixing the magnet in the rotor is not limited to the above embodiment.

〔Effect of the invention〕

As described above, according to the present invention, by recessing the groove in the opening end face of the yoke, it is possible to suppress outward bulging deformation of the opening during high-speed rotation.

[Brief explanation of drawings]

FIG. 1 shows a flywheel mag 7 which is an embodiment of the present invention.
FIG. 2 is a partially omitted partially cutaway plan view, FIG. 3 is an enlarged partial sectional view of the first drawing, and FIG. 4 fa) (b) +(ri and Figure 5 (alTol
(C1 is each bulge deformation degree diagram showing the rotation test results for explaining the effect, and FIG. 6 is the same radius change amount diagram. 11...Yoke, 12...McNet, 13...・・・
Case, 14... Cover "-115... Holder ring, 16... Shaft hole, 17... Mounting hole, 18...
Convex portion, 19... Winding caulking allowance, 20... Groove, 30
...Cylinder wall, 31...Accommodation chamber, 32...Bottom wall part,
33... Ring, 34... Concave portion, 35... Partition wall portion, 36... Holding portion. Agent Patent Attorney Tatsuya Kajihara Figure 1

Claims (4)

[Claims] (1) In a rotor of a magnet generator in which a plurality of magnets are arranged and fixed in an annular manner on the inner peripheral surface of a yoke formed in a substantially bottomed cylindrical shape, a groove is sunk in the open end surface of the yoke. A rotor of a magnet generator characterized by: (2) A rotor for a magnet generator according to claim 1, wherein the groove is formed in a series of annular shapes. (3) A rotor for a magnet generator according to claim 1, wherein the grooves are formed intermittently in an annular shape. (4) A rotor for a magnet generator according to claim 1, wherein the groove is formed so that its cross-sectional shape is approximately semicircular.