JPH11196563A - Magnetizing device of magnet for eddy current generated retarder and magnetizing method using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To magnetize non-magnetized magnet materials while they are fixed to a support ring. SOLUTION: A magnetizing device of a magnet for an eddy current generated retarder has a magnetizing coil 13 having a plurality of cores 13a protruding from the inner side of a cylindrical unit toward the center of the cylindrical unit and conductors 13b wound on the respective cores so as to make the inner surfaces of the adjacent cores have different polarities; a cylindrical yoke 14 provided in the magnetizing coil concentrically; and a space 15 into which a plurality of non-magnetized magnet materials can be inserted and which are formed between the magnetizing coil 13 and the yoke 14. The plurality of non-magnetized magnet materials are fixed to the circumferential part of a cylindrical support ring and inserted into the space 15. A current is applied to the magnetizing coil so as to make the adjacent polarities opposite to each other, and the plurality of magnet materials are magnetized simultaneously.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a permanent magnet magnetizing device incorporated in an eddy current type speed reducer provided as an automobile braking device, and a method of magnetizing a magnet material using the device.

[0002]

2. Description of the Related Art A braking device for an automobile is used to prevent a foot brake as a main brake, an exhaust brake as an auxiliary brake, a stable deceleration when descending a long hill, etc., and to prevent the burn of the foot brake. An eddy current type reduction gear (hereinafter referred to as "retarder") is used. Some of the retarders use permanent magnets as magnets, while others use electromagnets. Several examples of the structure of the retarder using the permanent magnet have already been proposed by the present applicant (for example, see Japanese Patent Application Laid-Open
JP 1-234043, JP-A 1-234045, JP 1-2989
No. 48, etc.).

FIG. 5 is a longitudinal sectional view showing an example of a retarder using a permanent magnet.

The rotor R includes a cylindrical portion 3, spokes 2, and a disk 1, and is attached to one end of the rotating shaft 10 via a bracket 10a. The end of the cylindrical portion 3 is joined to the tip of the spoke 2 in a cantilever manner, and a stator S containing a permanent magnet is provided therein.

The stator S includes a permanent magnet 5, a support ring 6, and a pole piece 7, and is housed in a casing 12. The pole piece 7 is in the shape of a strip, as shown in FIG.
As shown in the figure, a casing cover 12a is provided around the inside of the cylindrical portion 3.

FIG. 6 is a perspective view showing a state where a permanent magnet is fixed to a support ring.

The permanent magnet 5 is provided on the outer circumference of the support ring 6,
The polarities of the adjacent surfaces are opposite to each other and are fixed at equal intervals by the mounting bracket 6a and the mounting bolt 6b. As shown in FIG. 5, the permanent magnet 5 and the support ring 6
It is supported by a guide rod 11 fixed to a casing, and reciprocates in the axial direction by a piston rod 8 of a driving device 9.

The state where the permanent magnet 5 is inserted to the position of the pole piece 7 by the reciprocating movement, that is, the position where the permanent magnet 5 is magnetically opposed to the cylindrical portion 3 (the state shown in the upper half of the figure) is brake-on. Conversely, a state in which the permanent magnet 5 is away from the pole piece 7 (a state shown in the lower half of the figure) is braking off. In the brake-on state, the cylindrical portion 3 rotates across the magnetic flux generated from the permanent magnet 5, so that an eddy current flows near the inner wall surface of the cylindrical portion. Due to the interaction between the eddy current and the magnetic flux, a braking torque is generated in the rotor R.

[0009]

Generally, the work of incorporating a permanent magnet into a device is performed after the magnet is magnetized. This operation can be easily performed if the magnetic force is small. However, when a permanent magnet having a large shape and a high performance (strong) such as a nuclear magnetic resonance apparatus (MRI) is incorporated, the magnetic flux distribution is measured and adjusted. The installation is done manually, which is a difficult task.

The retarder proposed by the present applicant uses, for example, a permanent magnet containing a rare earth element, has a strong magnetic force, and has a large amount of incorporation (for example, from 12 to 32). (For example, 4-1335
No. 28). This device requires a lot of time for assembling since the permanent magnets are held one by one by a suction block and fixed to a support ring.

It is an object of the present invention to provide an apparatus capable of magnetizing a magnet material which has not been magnetized after the magnet material has been incorporated into a support ring, and a method of magnetizing using the apparatus.

[0012]

The gist of the present invention resides in a magnetizing apparatus for a non-magnetized magnet material shown in FIGS. 1 and 2 and a magnetizing method shown below using the apparatus.

A plurality of magnetic cores 13a projecting in the center direction are formed inside the cylindrical body, and a conductive wire 13b is wound around each of the magnetic cores 13a so that the tip surfaces of adjacent magnetic cores 13a have different polarities. A magnetizing coil 13 and a cylindrical yoke 14 provided concentrically inside the magnetizing coil are provided on a coil base 19 and magnetized between the magnetizing coil 13 and the yoke 14. A magnetizing device for a magnet for an eddy current type reduction gear provided with a space portion 15 where a magnetic material to be placed is provided (see FIG. 1).

At the center of the cylindrical yoke 14, an elevating device 17 which holds a support ring on which a magnet material to be magnetized is fixed and which can be inserted into the space 15 is desirably provided. (See FIG. 2).

[0015] A plurality of magnet materials to be magnetized are fixed to a circumferential portion of a cylindrical support ring, and a plurality of magnetizing coils are provided at positions on an outer peripheral portion opposed to the respective magnet materials.
A concentric yoke is provided at the center of the support ring, and an electric current is applied to the magnetizing coil so that adjacent magnets have opposite polarities, and the plurality of magnet materials are magnetized simultaneously. How to magnetize permanent magnets.

The magnet material is preferably an Nb-Fe-B permanent magnet material.

[0017]

1 is a partial view showing an example of a magnetizing device for a permanent magnet for a retarder according to the present invention, wherein (a) is a plan view and (b) is a view taken along the line AA of (a). It is a longitudinal cross-sectional view.

The magnetizing device for a permanent magnet for a retarder according to the present invention comprises a cylindrical magnetizing coil 13 and a cylindrical yoke.
14, and a space 15 is formed between the magnetizing coil 13 and the yoke 14.

The magnetizing coil 13 is formed by winding a conducting wire 13b around a plurality of magnetic cores 13a formed by projecting radially inward of a cylinder made of a laminated body of magnetic steel sheets. The conductor is wound or the direction of the current is adjusted so that the magnetic poles at the tip of the core are opposite on the adjacent surface.

The yoke 14 has a cylindrical shape made of a ferromagnetic material, is provided concentrically inside the magnetizing coil, and has a space 15 between itself and the magnetizing coil 13. The yoke shown in FIG. 1 is a cylindrical body, but may be a cylindrical body. In addition, since the yoke is provided to form a magnetic path for passing magnetism, the thickness of a support ring for fixing a magnet material to be magnetized (hereinafter simply referred to as “magnet material”) is large. Need not be provided. However, recently, in order to reduce the weight of the retarder, it is desirable to provide a yoke with a small thickness of the support ring.

FIG. 2 is a diagram showing a magnetizing device having a lifting device provided at the center of the yoke, wherein (a) is a plan view seen from above,
(b) is a partial longitudinal sectional view. This figure shows a state in which the elevating device 17 is pushed up by the hydraulic device 18, and a support ring to which the magnet material is fixed is attached at this position.

The magnetizing coil 13 and the yoke 14 are provided with a space 15 as shown in FIG.
And a lifting device 17 is provided at the center of the yoke 14.

The elevating device 17 comprises an elevating shaft 21 supported by a bush 20 fixed to a coil base 19 and a hydraulic device 18 fixed to an underframe 22.

At the upper end of the elevating shaft 21, there is provided a mounting table 23 for mounting a holder for holding a support ring to which a magnetic material described later is fixed, and at the lower end of the elevating shaft, an elevating table 24 is provided. Then, the lifting shaft 21 is raised and lowered by the hydraulic device 18 provided below the lifting table 24. The hydraulic device 18 is fixed via a bracket 26 attached to a guide rod 25 hanging down from the underframe 22. The guide bar 25 slides a guide bush 27 provided on the lifting platform 24 to vertically move the lifting shaft 21 vertically. A stopper 28 is provided on the bracket 26 to align the magnet material and the magnetizing coil 13 in the height direction when the elevating shaft 21 is lowered.

A method of magnetizing the magnet material 5A using the magnetizing device of the present invention will be described.

First, the magnet material 5A is, for example, a strip-shaped non-magnetic magnet material containing a rare earth element. As shown in FIG. 6, a metal fitting 6A made of a non-magnetic material and a bolt 6b are formed on the outer peripheral surface of the support ring 6 as shown in FIG. Are fixed at equal intervals. Since the magnetic material has no magnetic force, it can be easily attached to the support ring by human power.

FIG. 3 is a view for explaining a situation in which a magnet material is magnetized using the magnetizing device of the present invention. The support ring 6 to which the magnet material 5A is fixed as described above is inserted into the space 15 between the magnetizing coil 13 and the yoke 14, and the outer peripheral surface of the magnet material 5A and the inner peripheral surface of the magnetizing coil 13 have a radius. It is installed at the position facing in the direction. When a current is passed through the magnetizing coil in this state,
As shown in the figure, a magnetic field 16 is generated in the adjacent magnetic core 13a, and the plurality of magnet materials 5A are simultaneously vertically magnetized, so that the adjacent outer peripheral surfaces become permanent magnets having different polarities.

Next, the step of magnetizing using the magnetizing device shown in FIG. 2 will be described.

FIG. 4 is a view for explaining a step of attaching a magnet material to the magnetizing device of the present invention. FIG. 4 (a) shows a holder (a left half) and a holder (holding a support ring to which the magnet material is fixed). (B) is a vertical cross-sectional view of a holder holding a support ring to which the magnet material is fixed, (c) is a vertical cross-sectional view of a mounting table provided at the tip of the elevating shaft, (d) ) Is a longitudinal sectional view showing a state where the holder is attached to the mounting table,
(e) is a plan view of (d).

As shown in FIG. 3B, the support ring 6 having the above-described magnet material 5A fixed to the outer peripheral surface is concentrically attached to the lower surface of the holder 29 by bolts B1.

The holder 29 has a circular hole 29a, a bolt hole 29b, and a hole 29c for wedging therein, and is preferably made of a non-magnetic material such as aluminum.

The mount 23 of the elevating device 17 has a step 23a and a wedge stopper ring 23b, and is attached to the tip of the elevating shaft 21 by a bolt B2, as shown in FIG. Holder 2 with magnet material 5A and support ring 6 attached as shown in FIG.
9 is placed on the mount 23 from above, the step 23a of the mount and the hole 29a of the holder are fitted, and the holder is placed and fixed concentrically. As shown in FIG.
The wedge retaining ring 23b provided in 9 is put through the wedge hole 29c of the holder and placed, and the wedge K is driven into the wedge retaining ring 23b and fixed. This fixing operation is performed in the state of the magnetizing device shown in FIG. 2 (b).

Since the support ring 6 on which the magnet material 5A is disposed is fixed to the lower part of the holder 29 in a state of being suspended therefrom, the lifting device 17 is hydraulically moved as shown by arrows at both ends in FIG. When lowered by the device 18, the magnetizing coil 13 and the yoke 14
Is inserted into the space 15 between the two. It is necessary to insert the magnetizing coil and the magnet material at positions facing each other in the radial direction. However, since the elevating shaft 21 does not rotate, the bolt holes 29 of the holder 29 are not rotated.
It depends on the position of b and the wedge hole 29c. When a current is applied to the magnetizing coil 13 in this state, the surface of the adjacent outer peripheral portion of the magnet material 5A is magnetized to a different polarity.

[0034]

[Example] 16 magnet materials containing a rare earth element having a length of 27 mm, a width of 57 mm, and a thickness of 9.5 mm, an inner diameter of 342 mm and an outer diameter of 365
mm, prepare a support ring made of ferromagnetic material with a width of 31 mm,
The magnet material was fixed to the outer peripheral surface of the support ring at regular intervals by using a non-magnetic material mounting bracket and a bolt.

The support ring on which the magnet material was fixed was set in the magnetizing device shown in FIG. 2 in the process shown in FIG. 4, and the magnetizing test was performed by changing the power supply voltage of the magnetizing coil from 300 V to 750 V. .

As a comparative example, an already magnetized permanent magnet was fixed to a support ring using the apparatus disclosed in Japanese Utility Model Laid-Open No. 4-33528.

The magnetic field strength of these permanent magnets was measured with a flux meter, and the relationship between the power supply voltage and the magnetic field strength is shown in FIG.

From these results, the power supply voltage was changed from 300 V to 7
It can be seen that when the voltage is changed to 50 V, the magnetic field intensity changes from 2450 Mx to 2570 Mx. The saturation magnetization (full magnetization) of this magnet material is 2570Mx, which is equivalent to a magnetized permanent magnet fixed to a support ring. That is, if a voltage of 675 V or more is applied, a magnetic field intensity equivalent to that of the related art can be obtained.

When the magnetizing device of the present invention is used, a magnet material having no magnetic force can be fixed to the support ring, so that the work becomes easy and the work time is reduced from 11 minutes in the comparative example to 5 minutes. be able to.

[0040]

According to the magnetizing apparatus of the present invention, a magnet material having no magnetism can be magnetized to an arbitrary magnetic field strength after the magnet material is incorporated into the support ring. It has become possible to shorten the magnetizing time, simplify the magnet assembling work, or automate the magnet assembling work that has been difficult so far.

[Brief description of the drawings]

FIG. 1 is a view showing an example of a magnetizing device for a permanent magnet for a retarder according to the present invention, wherein (a) is a plan view and (b) is a longitudinal sectional view taken along the line AA of (a).

FIGS. 2A and 2B are diagrams showing a magnetizing device provided with a lifting device at the center of a yoke, wherein FIG. 2A is a plan view as viewed from above, and FIG.

FIG. 3 is a diagram illustrating a situation in which a magnet material is magnetized using the magnetizing device of the present invention.

4A and 4B are diagrams illustrating a process of attaching a magnet material to the magnetizing device of the present invention, and FIG. 4A illustrates a holder (right half) holding a mounting base (left half) and a support ring to which the magnet material is fixed. (B) is a vertical cross-sectional view of a holder holding a support ring to which a magnet material is fixed, (c) is a vertical cross-sectional view of a mounting table provided at the tip of a lifting shaft, and (d) is a holding section. FIG. 6 is a vertical cross-sectional view showing a state where the tool is mounted on a mounting table, and FIG.

FIG. 5 is a longitudinal sectional view showing an example of a retarder using a permanent magnet.

FIG. 6 is a perspective view showing a state where a permanent magnet is fixed to a support ring.

FIG. 7 is a diagram showing a relationship between a power supply voltage and a magnetic field strength.

[Brief description of reference numerals]

 R. Rotor S. Stator 1. Disk 2. Spokes 3. Cylindrical part 4. Fins 5. Permanent magnet 5A. Magnet material 6. Support ring 7. Pole piece Piston rod9. Drive device 10. Rotary axis 10a. Bracket 11. Guide rod 12． Casing 12a. Casing cover 13. Magnetizing coil 14． York 15． Spatial part 16. Magnetic field 17. Lifting device 18． Hydraulic equipment 19. Coil base 20. Bush 21. Elevating shaft 22. Underframe 23. Mounting stand 23a. Step 23b. Wedge retaining ring 24. Elevator 25. Guide bar 26. Bracket 27. Guide bush 28. Stopper 29. Holder 29a. Circular hole 29b. Bolt hole 29c. Wedge hole

Claims (3)

[Claims] A plurality of magnetic cores protruding in the center direction are formed inside a cylindrical body, and a lead wire is wound around each of the magnetic cores so that the tip surfaces of adjacent magnetic cores have different polarities. A space in which a magnet coil and a cylindrical yoke provided concentrically inside the magnetizing coil are provided on a coil base, and a magnet material to be magnetized is placed between the magnetizing coil and the yoke. A magnetizing device for a magnet for an eddy current type speed reducer, wherein a magnet is provided. 2. The apparatus according to claim 1, wherein said yoke is provided at a center thereof with a lifting device which holds a support ring on which a magnetic material to be magnetized is fixed and which can be inserted into said space. 3. A magnetizing device for a magnet for an eddy current type speed reducer according to claim 1. 3. A plurality of magnet materials to be magnetized are fixed to an outer circumferential portion of a cylindrical support ring, and a plurality of magnetizing coils are provided at a position of an outer circumferential portion facing each magnet material. Provided,
A yoke is disposed concentrically at the center of the support ring, and a current is applied to the magnetizing coil so that adjacent polarities are opposite to magnetize the plurality of magnet materials simultaneously. Method for magnetizing permanent magnets for eddy current type reduction gears.