JP3882395B2 - Eddy current reducer - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a disk-type eddy current reduction device that assists a friction brake of a large vehicle, and more particularly to a eddy current reduction device that is small in size and excellent in heat dissipation.
[0002]
[Prior art]
For example, in the eddy current reduction device disclosed in Japanese Patent Application No. 10-106963 and the like, a guide cylinder that accommodates a magnet support cylinder is accommodated in the brake drum, so that heat generated in the brake drum during braking is dissipated. Is not sufficient, and there is a problem that the braking ability is remarkably lowered when the brake drum is overheated.
[0003]
[Problems to be solved by the invention]
In view of the above problems, an object of the present invention is to provide an eddy current reduction device that is small in size, excellent in heat dissipation, and high in braking ability.
[0004]
[Means for Solving the Problems]
In order to solve the above problems, the configuration of the present invention includes a brake disc coupled to a rotating shaft, a guide cylinder made of a non-magnetic material that is disposed on a non-rotating portion of the vehicle body so as to face a side surface of the brake disc, A magnet support wheel supported in the inner space of the guide cylinder so as to be rotatable forward and backward, a large number of magnets coupled to the magnet support wheel at equal intervals in the circumferential direction, and a ferromagnetic coupled to both circumferential ends of the magnets A magnetic pole member comprising a body, and a ferromagnetic plate provided on an end wall of the guide cylinder facing the brake disc so as to face a side surface of each magnetic pole member, and the magnet support wheel, the magnet, and the magnet Each side surface with the magnetic pole member is formed so as to form a flat continuous surface parallel to the side surface of the braking disk, and the braking disk is caused to generate a braking force based on an eddy current due to a magnetic field from the magnet. Features.
Further, the configuration of the present invention includes a pair of brake discs coupled to a rotating shaft, and a non-magnetic body installed between the pair of brake discs on a non-rotating portion of the vehicle body so as to face a side surface of the brake disc. A guide cylinder comprising: a magnet support wheel supported in an inner space of the guide cylinder so as to be capable of forward and reverse rotation; a number of magnets coupled to the magnet support ring at equal intervals in the circumferential direction; and the circumferential direction of each magnet A magnetic pole member made of a ferromagnetic material coupled to both ends, and a ferromagnetic plate provided on both end walls of the guide tube so as to face both side surfaces of the magnetic pole member, the magnet support ring, the magnet, and the magnet Each side surface with the magnetic pole member is formed so as to form a flat continuous surface parallel to the side surface of the braking disk, and a braking force based on an eddy current due to a magnetic field from the magnet is generated on the front braking disk. It is characterized by.
[0005]
DETAILED DESCRIPTION OF THE INVENTION
In the present invention, a guide cylinder made of a non-magnetic material is installed on the non-rotating portion of the vehicle body so as to face the side surface of the brake disc coupled to the rotating shaft. A large number of magnets are coupled at equal intervals in the circumferential direction to a magnet support wheel supported in the inner space of the guide cylinder so as to be able to rotate forward and backward. Side surfaces of a magnetic pole member made of a ferromagnetic material coupled to both ends in the circumferential direction of each magnet are made to face a ferromagnetic plate (pole piece) provided on an end wall facing the brake disk of the guide tube. The rotating braking disk generates a braking force based on an eddy current caused by a magnetic field from the magnet. During non-braking, the magnet support wheel is rotated so that the side surface of the magnetic pole member does not face the ferromagnetic plate.
[0006]
【Example】
As shown in FIG. 1, the eddy current reduction device faces a side surface of a brake disc 3 coupled to a rotating shaft 2, and a guide cylinder 4 made of a nonmagnetic material is supported on a non-rotating part such as a vehicle body. The guide cylinder 4 includes an inner cavity portion 10 having a rectangular cross section surrounded by an outer cylinder portion 4a, an inner cylinder portion 4b, an outer end wall 4c, and an inner end wall 4d, and an inner end facing the side surface of the brake disc 3 A large number of ferromagnetic plates (pole pieces) 8 are provided on the wall 4d at equal intervals in the circumferential direction. Preferably, the ferromagnetic plate 8 is cast when the guide tube 4 is cast from a nonmagnetic material such as aluminum. A magnet support wheel 5 made of a non-magnetic material is supported in the inner space 12 of the guide tube 4 so as to be able to rotate forward and backward. For example, the magnet support wheel 5 is engaged with a gear of the main shaft of the electric motor provided in the guide cylinder 4 by meshing a gear provided on a shaft portion that protrudes outside through a slit of the outer end wall 4 c of the guide cylinder 4. It is configured to be able to rotate forward and backward. A large number of block-shaped magnets 7 are supported on the magnet support wheel 5 at equal intervals in the circumferential direction, and magnetic pole members 6 made of a ferromagnetic material are coupled to both end surfaces of the magnet 7 in the circumferential direction. The side surface of the tip of the magnetic pole member 6 is opposed to the ferromagnetic plate 8. The magnet 7 and the magnetic pole member 6 are cast when the magnet support wheel 5 is cast. In the illustrated embodiment, since the circumferential dimension t of the magnet 7, the magnetic pole member 6, and the ferromagnetic plate 8 is substantially the same, the magnet 7 is disposed on the magnet support wheel 5 at every arrangement interval 4t.
[0007]
In the above eddy current reduction device, during braking, as shown in FIG. 2, the magnetic pole members 6 coupled to both ends in the circumferential direction of the magnet 7 are opposed to the ferromagnetic plates 8 on the inner end wall 4d, and the magnet 7 generates a magnetic field. It exerts on the brake disk 3 through the magnetic pole member 6 and the ferromagnetic plate 8. When the rotating braking disk 3 crosses the magnetic field, a braking torque based on eddy current is generated inside the braking disk 3. At this time, a magnetic circuit z is formed between the magnet 7 and the brake disc 3.
[0008]
As shown in FIG. 3, when releasing the braking, the magnet support wheel 5 is rotated by a quarter of the arrangement pitch of the magnet 7 (half arrangement pitch of the ferromagnetic plate 8). 8, a short-circuit magnetic circuit w is formed between the magnetic pole member 6 and the ferromagnetic plate 8, and no magnetic field is applied to the brake disc 3.
[0009]
As shown in FIG. 4, if the ferromagnetic plate 9 is disposed on the inner surface of the outer end wall 4 c of the guide tube 4 so that the ferromagnetic plate 9 faces the magnet 7 during non-braking, the magnetic member 7 extends from the magnet 7. 6, a magnetic circuit w is generated in the ferromagnetic plate 9 and the magnetic pole member 6 on the opposite side, and a leakage magnetic field from the magnet 7 to the braking disk 3 can be suppressed.
[0010]
As shown in FIG. 5, instead of disposing the ferromagnetic plate 9 on the outer end wall 4c, the ferromagnetic plate 9a is opposed to the magnet 7 on the inner surface of the inner cylindrical portion 4b (or outer cylindrical portion 4a) and 1 You may arrange | position so that a pair of magnetic pole member 6 may be straddled.
[0011]
In the embodiment shown in FIG. 6, a guide cylinder 4 made of a non-magnetic material is disposed between a pair of left and right brake discs 3 made of a conductor coupled to the rotating shaft 2, and a large number of both end walls 4 d of the guide cylinder 4 are provided. The ferromagnetic plates 8 are arranged at equal intervals in the circumferential direction. A magnet support wheel 5 made of a nonmagnetic material is supported in the inner space 10 of the guide tube 4 so as to be able to rotate forward and backward. A large number of block-shaped magnets 7 are coupled to the magnet support wheel 5 at equal intervals in the circumferential direction, and a pair of block-shaped magnetic pole members 6 are coupled to the circumferential ends of the magnets 7. In addition, a ferromagnetic plate 9 a that faces the non-braking magnet 7 and straddles the pair of magnetic pole members 6 is disposed on the inner surface of the inner cylinder portion 4 b of the guide cylinder 4.
[0012]
The eddy current reduction device shown in FIG. 6 also rotates the magnet support ring 5 forward and backward by the 1/4 arrangement pitch of the magnet 7 (half arrangement pitch of the ferromagnetic plate 8), similarly to those shown in FIGS. Thus, the braking position where the side surface of the magnetic pole member 6 extending from the circumferential end of the magnet 7 faces the ferromagnetic plate 8 of the end wall 4 d of the guide cylinder 4, and the side surface of the magnetic pole member 6 does not face the ferromagnetic plate 8. Switch to the non-braking position.
[0013]
【The invention's effect】
As described above, the present invention provides a brake disc coupled to the rotating shaft, a guide cylinder made of a non-magnetic material disposed on a non-rotating portion of the vehicle body so as to face the side surface of the brake disc, A magnetic pole member comprising a magnet support ring supported in the hollow portion so as to be able to rotate forward and backward, a large number of magnets coupled to the magnet support ring at equal intervals in the circumferential direction, and a ferromagnetic material coupled to both circumferential ends of each magnet. And a ferromagnetic plate provided on the end wall of the guide cylinder facing the brake disc so as to face the side surface of each magnetic pole member, and each of the magnet support wheel, the magnet, and the magnetic pole member The side surface is formed so as to form a flat continuous surface parallel to the side surface of the braking disk, and generates a braking force based on an eddy current due to a magnetic field from the magnet on the braking disk. The outer cylinder part and the inner cylinder part are exposed to the outside air, and the outside air easily enters the gap between the brake disc and the guide cylinder. , Heat generated brake disc during braking is efficiently released. Therefore, a decrease in braking ability due to heat during braking can be suppressed.
[0014]
In particular, since the outside air is easily taken in between the guide cylinder and the brake disc, the thermal distortion of the brake disc can be minimized. This eliminates the need for structural measures against heat, simplifying the structure and reducing manufacturing costs.
[0015]
The structural space of the switching mechanism for switching between non-braking and braking position is reduced, and the entire apparatus can be miniaturized.
[Brief description of the drawings]
FIG. 1 is a front sectional view of an eddy current reduction device according to the present invention.
FIG. 2 is a plan sectional view showing the braking state of the eddy current reduction device developed in the circumferential direction.
FIG. 3 is a plan sectional view showing the unbraking state of the eddy current reduction device developed in the circumferential direction.
FIG. 4 is a plan sectional view showing an eddy current reduction device according to a partially modified embodiment of the present invention developed in the circumferential direction.
FIG. 5 is a cross-sectional plan view showing an eddy current reduction device according to a partially modified embodiment of the present invention developed in the circumferential direction.
FIG. 6 is a front sectional view of an eddy current reduction device according to a second embodiment of the present invention.
[Explanation of symbols]
2: Rotating shaft 3: Braking disc 4: Guide tube 4a: Outer tube portion 4b: Inner tube portion 4c: Outer end wall 4d: Inner end wall 5: Magnet support ring 6: Magnetic pole member 7: Magnet 8: Ferromagnetic plate 9: Ferromagnetic plate 9a: Ferromagnetic plate 10: Inner space

Claims (2)

A brake disc coupled to the rotating shaft, a guide cylinder made of a non-magnetic material installed in a non-rotating portion of the vehicle body facing the side surface of the brake disc, and a forward / reverse rotation in the inner space of the guide cylinder A magnet support wheel supported on the magnet, a large number of magnets coupled to the magnet support ring at equal intervals in the circumferential direction, a magnetic pole member composed of a ferromagnetic material coupled to both circumferential ends of each magnet, and the braking of the guide cylinder A ferromagnetic plate provided on an end wall facing the disc so as to face a side surface of each magnetic pole member, and each side surface of the magnet support wheel, the magnet, and the magnetic pole member is formed of the brake disc. An eddy current reduction device, wherein the eddy current reduction device is formed so as to form a flat continuous surface parallel to a side surface and generates a braking force based on an eddy current caused by a magnetic field from the magnet on the braking disk. A pair of brake discs coupled to a rotating shaft, a guide cylinder made of a non-magnetic material installed in a non-rotating portion of the vehicle body so as to face a side surface of the brake disc between the pair of brake discs, A magnet support wheel supported in the inner space of the guide cylinder so as to be able to rotate forward and backward, a large number of magnets coupled to the magnet support ring at equal intervals in the circumferential direction, and a ferromagnetic material coupled to both circumferential ends of each magnet And a ferromagnetic plate provided on both end walls of the guide cylinder so as to face both side surfaces of the magnetic pole member, and the side surfaces of the magnet support ring, the magnet, and the magnetic pole member are An eddy current deceleration characterized by forming a flat continuous surface parallel to the side surface of the braking disk and generating a braking force based on an eddy current due to a magnetic field from the magnet on the front braking disk apparatus.

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