JPH0624166B2 - Permanent magnet magnetizing device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a permanent magnet manufacturing apparatus in which N poles and S poles are alternately continuous, and particularly preferably used as an armature or field of an electric motor and between the poles. The present invention relates to a permanent magnet manufacturing apparatus having a non-magnetic flux region or a weak magnetic flux region.

(Prior Art) Conventionally, there is an electric motor as a typical row of devices having permanent magnets in which N poles and S poles are alternately continuous. For example, in a DC electric motor, a cylindrical or disk-shaped permanent magnet is used as a field or armature. Is used. In this case, for example, assuming that the number of poles is 4, the magnetic poles of the cylindrical and disc-shaped permanent magnets are distributed as shown in FIGS. 1 (a) and (b), and the magnetic field along the circumferential direction is The strength is as shown in FIG.

As is clear from FIG. 2, it is difficult to improve the efficiency and characteristics of the electric motor because there is no magnetic flux region or weak magnetic flux region between adjacent magnetic poles.

FIG. 3 (a) is a diagram showing a typical example (for 4 poles) of a magnetizing device for producing the conventional permanent magnet shown in FIG. 1 (a), and FIG.
(b) is a figure which shows the effect. 2 in FIG. 3 (a)
Reference numeral 0 denotes a magnetizing yoke, which is preferably made of a ferromagnetic material, and 22 denotes a magnetizing coil, which is connected to a DC power supply 26 via a switch 28. Reference numeral 24 is a magnetic material, for example, a cylindrical magnetized object. A coil 22 is wound around each of the protrusions 20a to 20d of the magnetizing yoke 20, and a DC current is momentarily applied to the coil 22 to remove the magnetized object 24 from the protrusion 20b as shown in FIG. 3 (b). Since the magnetic flux flows into the convex portion 20a through it, the S pole and the
An N pole is generated and magnetized, and the strength distribution of the magnetic field due to it is as shown in FIG. 3 (c), and there is no non-magnetic flux or weak magnetic flux region.

Therefore, conventionally, a plurality of divided permanent magnets of each pole for fixing a weak magnetic flux region between the poles are fixed to each other through an adhesive or a fixing metal fitting, for example, as shown in FIGS. 4 to 6. Is known as.

These constitute an armature of an electric motor. Fig. 4 shows an armature in which a permanent magnet is fixed by a holding metal fitting, and a front sectional view (a) is taken along the line AA in the side view (b). A cross section is shown, in which the permanent magnets 2 are fixed to the yoke 8 by pressing metal fittings 4 including screws. In the figure, 6 is a rotating shaft.
In this case, the pressing metal part is in a weak magnetic flux region, but the work of fixing the permanent magnet with the pressing metal is troublesome, resulting in poor work efficiency and high cost. 5 and 6 show an armature in which a permanent magnet is fixed by a bind wire and a thin stainless steel tube, respectively, and a side sectional view (b) is a sectional view taken along line AA of the front view (a). FIG. 5 and FIG. 6 respectively show the permanent magnet 2 fixed to the yoke 8 with, for example, a stainless bind wire 10 and a thin-walled stainless steel cylinder 12, and the stainless portion between the magnets is a weak magnet area, but the fixing work is troublesome. Therefore, the magnetic force of the permanent magnet decreases due to the binding wire and the cylinder, and the thickness increases the distance between the armature and the field, which further decreases the magnetic force, and the performance as an electric motor is reduced. However, there is a high risk of causing problems such as deterioration of the adhesive portion due to aging, or loosening of the fixing portion due to vibration and the permanent magnet coming off.

(Problems to be Solved by the Invention) An object of the present invention is to eliminate the above-mentioned drawbacks of the conventional magnetizing device for a permanent magnet, in which the S pole and the N pole are alternately arranged through a non-magnetic flux region or a weak magnetic flux region. It is to provide a magnetizing device for producing a permanent magnet that is continuous, has high performance and high reliability, and has high assembly work efficiency.

(Means for Solving the Problems) In order to achieve such an object, the magnetizing device for a permanent magnet of the present invention is made of a magnetic material integrally provided on one surface of a magnetic material piece and alternately arranged in a row. A plurality of first and second protrusions, and the first and second protrusions between adjacent first and second protrusions
A plurality of third protrusions made of a magnetic material integrally provided on one surface of the magnetic material piece so as to be arranged alternately with the protrusions, and connected to a DC power source via a switch, First above
And a plurality of short-circuit coils each wound around each of the third protrusions, and a coil means continuously wound in series around the second protrusion. The winding directions of the coil means in the projecting portion are opposite to each other, and the magnetized piece is opposed to the one surface of the magnetic material piece to momentarily close the switch, thereby instantaneously closing the switch. One of the N pole and the S pole is located in the region of the magnetized piece facing the first protrusion, the other of the N pole and the S pole is located in the region facing the second protrusion, and the third protrusion is formed. A non-magnetic flux region or a weak magnetic flux region is formed in a region facing to each other so that the magnetized piece is a permanent magnet. That is, one magnetic flux of the N pole or the S pole is generated in the first protruding portion, the other magnetic flux of the N pole or the S pole is generated in the second protruding portion, and these magnetic fluxes pass through the magnetic pieces to be adhered. At the same time, a part of the magnetic flux passes through the third protrusion, and when the short-circuit coil of the third protrusion generates a magnetic flux that cancels these magnetic fluxes, there is a phase delay of about 90 ° with respect to the current of the coil means. An electric current flows. Therefore, the magnetic fluxes passing through the third protrusions cancel each other out, resulting in a small amount of magnetic flux passing therethrough.
Therefore, the magnetizing device having such a simple structure can magnetize the magnetized piece alternately so that the N pole non-magnetic flux (or weak magnetic flux) region and the S pole are continuous, and the permanent magnet has a complicated structure. (EN) Provided is a permanent magnet which can be manufactured easily and inexpensively without requiring an assembling work and which has high reliability and high performance.

(Example) Hereinafter, an example of a magnetizing device for a permanent magnet according to the present invention will be described in detail with reference to the accompanying drawings.

7A and 7B show typical examples of permanent magnets produced by the magnetizing device of the present invention. FIG. 7A shows a cylindrical shape, and FIG. 7B shows a disk shape. N pole 30a, 40a, weak magnetic flux or non-magnetic flux region 30b, 40b,
The S poles 30c and 40c are preferably alternately arranged in series and are preferably armatures of electric motors or permanent magnets for a field, which is an example of four poles. The magnetic field strength distribution of such a permanent magnet is shown in FIG. 8 and has a no magnetic flux or weak magnetic flux region 30b between the N pole and the S pole. As described above, the permanent magnet formed by the magnetizing device according to the present invention clearly has no magnetic flux or a weak magnetic flux region. Therefore, when this permanent magnet is used as a field or armature of an electric motor, The efficiency and characteristics are improved, and since it is formed from one piece of magnetic material, assembly work is unnecessary, work efficiency is high, and a permanent magnet that is strong against vibration during use and highly reliable is provided.

Next, a method and apparatus for magnetizing a permanent magnet according to the present invention for manufacturing such a permanent magnet will be described. Fig. 9
FIG. 9A is a top view of a typical example of a magnetizing device for producing the permanent magnet shown in FIG. 7A, and FIG. 9B is a perspective view of the magnetizing device. In the figure, the same symbols as those in FIG. 3 have the same functions.

As is apparent from the figure, the magnetizing yoke 20 has the convex portions 20a, 20
Short-circuiting yokes (projections) 21a, 21b, 21c, 21d are provided between b, 20c, and 20d, respectively.
1a to 21d include short-circuit coils 50a, 50b, 50
c and 50d are wound. Shorting coils 54a-50
Each d is a short-circuit coil having a plurality of turns (preferably one or two turns).

A magnetizing method using the magnetizing device shown in FIG. 9 will be described with reference to FIGS. 9 and 10. FIG. 10 (a) is a partially enlarged view of the top view of the magnetizing device. First, when the switch 28 is momentarily closed and a current is applied to the magnetizing coil 22, the magnetic flux F is applied to the magnetizing yokes 20a and 20b, respectively. Part of the generated magnetic flux F1 passes through the short-circuiting yoke 21b in opposite directions. Since the currents flowing through the short-circuit coil 50b due to the magnetic flux F1 flow in directions canceling each other out, ideally the magnetic flux F2 is not generated from the short-circuit coil 50b. However, in practice, the magnetizing yokes 20a and 20b and the magnetic material 3
Variations in the gap between the 0, the magnetic flux density of both the magnetic flux F1 through the shorting yoke 21b by variations in these materials are not equal, therefore a short circuit coil 50b magnetic flux F ₂ to cancel the difference between the two magnetic flux F1 Coil 22 to generate
The current flows with a phase delay of about 90 ° with respect to the current inside.
Therefore, in the short-circuiting yoke 21b, the magnetic fluxes F ₁ and F ₂ cancel each other out, resulting in a small amount of magnetic flux passing through the short-circuiting yoke. Thus, as shown in the respective magnetic field strength distributions of (a), (b), and (c) of FIG. 8, the weak magnetic flux (or no magnetic flux) region 30b is provided in the portion facing the short-circuiting yokes 21a to 21d. . As is clear from FIG. 8, the magnetic field distribution in this non-magnetic flux region is symmetrical from the center point to the north pole and south pole directions. Therefore, when it is used as an armature or a field of an electric motor, the efficiency is improved.

By the way, the maximum magnetic field strength Hm and its width W in the non-magnetic flux (weak magnetic flux) range are the resistance value of the short-circuit coil 50, the width Y _W of the short-circuiting yoke 21b (FIG. 10 (b)), the top of the short-circuiting yoke. And the gap value Y _G between the top of the convex portion of the magnetizing yoke (10th
(B)) etc.

That is, the smaller the resistance value of the short-circuit coil 50, the higher the density of the generated magnetic flux F ₂ , and therefore the magnetic flux F ₁ is strongly canceled and the maximum magnetic field strength Hm (A / m) becomes weaker. That is, the smaller the number of turns of the coil 50 and the smaller the resistivity of the material of the coil 50, the smaller Hm becomes. For this reason, a single-turn coil (copper plate) preferably made of copper as shown in FIG. 11 is used as the short-circuit coil.

Further, the wider the width YW of the short-circuiting yoke, the larger the width _W of the non-magnetic flux (weak magnetic flux) region.

Further, the larger the gap Y _G , the more the magnetic flux passing through the short-circuiting yoke is diffused, and the width W becomes narrower. Therefore preferably the gap Y _G is 1~2mm For permanent magnet such as small electric motors.

Therefore, in FIG. 8, (a) is the case where the resistance of the short-circuit coil is larger than that of (b), and (c) is the width Y _W compared to (b).
Is large or the gap Y _G is small.

The permanent magnet magnetizing device of the present invention may be used not only for the armature of an electric motor as in the above-mentioned embodiment but also for creating a magnetic field, and further, for a linear motor such as a permanent magnet for a linear motor, a linear field or electric machine. It may be used for making a child, and the magnetizing device in that case is as shown in FIG.

The permanent magnet magnetizing device of the present invention is not limited to an electric motor or a linear motor, and it is required that the S poles and the N poles are alternately continuous through a non-magnetic flux (or weak magnetic flux) region. It can be applied to all permanent magnets.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of a conventional permanent magnet, FIG. 2 is a diagram showing a magnetic field strength distribution of the permanent magnet of FIG. 1, and FIG. 3 is a diagram showing a typical example of a conventional permanent magnet magnetizing device. 4 to 6 are views for explaining a conventional permanent magnet fixing method having a weak magnetic flux region, and FIG. 7 is a view of a typical example of a permanent magnet produced by the magnetizing device according to the present invention. 8 is a diagram showing the magnetic field strength distribution of the permanent magnet of FIG. 7, FIG. 9 is an example of the magnetizing device of the present invention, and FIG. 10 is a diagram for explaining the principle of the magnetizing device of FIG. FIG. 11 is a diagram showing an example of a short-circuit coil, and FIG. 12 is a diagram showing another example of the magnetizing device according to the present invention.

Claims (8)

[Claims] 1. A plurality of first and second protrusions made of a magnetic material, which are integrally and alternately provided in a row on one surface of a magnetic material piece, and adjacent first and second protrusions. Between the first and second
A plurality of third magnetic materials integrally provided on the one surface of the magnetic material piece so as to be alternately arranged with the protrusions.
Connected to the DC power supply via the switch and all the above-mentioned first
And a coil means continuously wound in series on the second protrusion, and a plurality of short-circuit coils wound on the respective third protrusions in an electrically isolated state. The winding directions of the coil means in the first and second protrusions are opposite to each other, and the magnetized piece is opposed to the one surface of the magnetic material piece to momentarily close the switch. Accordingly, one of the N pole and the S pole is located in the region of the magnetized piece facing the first protrusion, the other of the N pole and the S pole is located in the region facing the second protrusion, and the third pole is formed. A magnetizing device for a permanent magnet that forms a non-magnetic flux region or a weak magnetic flux region in a region facing the protrusion. 2. The heights of the tops of the first and second protrusions are substantially equal to each other, and the heights of the tops of the third protrusions are the first and second heights. A magnetizing device for a permanent magnet, which is lower than the top of the protrusion. 3. The magnetizing device for a permanent magnet according to claim 1, wherein the short-circuit coil is a one-turn coil. 4. The magnetizing device for a permanent magnet according to claim 3, wherein the short-circuit coil is made of a copper plate. 5. The magnetizing of a permanent magnet according to claim 1, wherein the magnetic material piece has a cylindrical shape and the first, second, and third protrusions are provided on an inner surface thereof. apparatus. 6. The magnetizing device for a permanent magnet according to claim 1, wherein the magnetic material piece has a rectangular parallelepiped shape. 7. A first magnetic flux generating means for generating a magnetic flux of an N pole provided on one surface of the magnetic material piece, and a magnetic flux for an S pole provided on the one surface adjacent to the first magnetic flux generating means. And a second magnetic flux generating means that is provided on the one surface between the first and second magnetic flux generating means, passes a part of the magnetic flux generated by the first and second magnetic flux generating means, and strikes them. A permanent magnet magnetizing device comprising: a third magnetic flux generating means having a short-circuit coil for generating a magnetic flux to be erased. 8. A plurality of first magnetic flux generating means for generating magnetic fluxes of N poles arranged in a line on one surface of a magnetic material piece, and S arranged alternately on the one surface with the plurality of first magnetic flux generating means. A plurality of second magnetic flux generating means for generating magnetic flux of a pole, and a plurality of third magnetic flux generating means alternately arranged between the first and second magnetic flux generating means on the one surface. Magnetic flux generating means, and each of the third magnetic flux generating means includes the first and second magnetic flux generating means.
A permanent magnet magnetizing device having a short-circuit coil for passing a part of the magnetic flux generated by the magnetic flux generating means and generating a magnetic flux that cancels the magnetic flux.