JPH0873178A - Steel lifting device - Google Patents

Abstract

PURPOSE: To quickly attract and detach an attractive object by providing a magnetic member on the surface of a main permanent magnet member via a non-magnetic material, regarding the system where attraction and release modes are selected via the rotation of a built-in permanent magnet on the operation of a permanent magnet type lifting device. CONSTITUTION: When an attraction object 30 is attracted to yokes 7a and 7b, a main magnet member 10 and a sub-magnet member 14 have S-polarity at the side of the yoke 7a and N-polarity at the side of the yoke 7b, respectively. Thus, the magnetic fluxes 20d and 20e of the member 10 also flow in the same magnetic path as the magnetic fluxes 20a to 20c of the member 14, and an attractive force is thereby produced. Also, when the object 30 is detached, the member 10 is rotated by 180 degrees to form a close circuit in a magnetism circuit 1. In this case, the member 10 is formed out of a rotating permanent magnet 11, a non-magnetic plate 12 and a magnetic member 13 fitted thereto and, therefore, a magnetic force balance can be provided via a magnetic shortcircuit and the object 30 can be easily detached.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a permanent magnet type hoisting device used for adsorbing, hoisting, and transporting a magnetic material such as steel, and more particularly to a device for switching attachment / detachment by rotating a built-in permanent magnet. It is a thing.

[0002]

2. Description of the Related Art Conventionally, a hoisting device of this type has a main magnet rotating in a yoke and an auxiliary magnet fixed to the yoke, as described in, for example, Japanese Utility Model Publication No. 62-39020. More specifically, as shown in FIGS. 3 (a) and 3 (b), the lifting device supports the magnetic circuit part via the magnetic circuit part 1 and the magnetic blocking plate 2 made of a non-magnetic material, and attaches the hanging metal part 4 to it. Substrate 3 having
And they are integrally assembled by bolts 5. The magnetic circuit portion 1 has attraction surfaces 6a and 6b, respectively, and has a pair of yokes 7a and 7b made of a ferromagnetic material and non-magnetic spacers 8a and 8b interposed therebetween, and between the spacers 8a and 8b. It has a cylindrical hole 9 formed in. In the hole 9, a columnar main magnet 10 magnetized in a radial direction and magnetized in a single pole in the axial direction (Y direction) is rotatably arranged. The sub magnet 14 magnetized in the X direction is fixed to one of the lower portion of the non-magnetic spacer 8b and the upper portion of the non-magnetic spacer 8a.

With the above structure, when the main magnet 10 is rotated to the N-pole and S-pole positions (the polarities of the main magnet 10 and the auxiliary magnet 14 are the same) shown in FIG. It is excited so that the attraction surface 6a as the end portion has an N pole, and the attraction surface 6b as the end portion of the yoke 7b has an S pole, whereby a steel piece or a steel product can be attracted and lifted. Next, when the main magnet 10 is rotated by 180 ° and the polarities of the main magnet 10 and the sub magnet 14 are at different polarities (not shown), the demagnetization occurs, and the attraction surfaces 6a and 6b are de-excited and lose the attraction force. .

[0004]

In the above-described steel material hoisting device, the material and shape of the magnet are set so that the magnetic force of the main magnet and the magnetic force of the sub magnet are balanced and the attractive force disappears in the non-excited state. It However, when magnets are actually manufactured on a mass production basis, there is some variation in magnetic characteristics between magnets due to differences in composition between lots or within the same lot and differences in manufacturing conditions (such as heat treatment temperature). In some cases, variations in the dimensional tolerance that occur during machining are added, and the expected magnetic force balance cannot be obtained, which may interfere with the work of attaching and detaching the object to be adsorbed. Further, it is conceivable to use a magnetic short-circuit plate to balance the magnetic force of the main magnet and the magnetic force of the sub-magnet, but since a bypass circuit that passes through the magnetic short-circuit plate is formed even in the state where the object to be attracted is attracted, There is a problem that the magnetic force is lost and the adsorption force is reduced. Therefore, it is an object of the present invention to solve the problems existing in the above-mentioned prior art, and to provide a steel material hoisting device that can easily perform the work of desorbing an object to be adsorbed without lowering the adsorption force.

[0005]

In order to achieve the above object, according to the present invention, a cylinder is formed in a substantially central portion of a pair of yokes facing each other with a spacer made of a non-magnetic material and each having an attracting surface. A yoke member having a circular hole, a main permanent magnet member rotatably arranged in the hole and having a magnetic pole in the radial direction, and a magnetic pole corresponding to the polarity of the main permanent magnet member in the thickness direction. In a steel material suspension device having a magnetic circuit structure composed of magnetized and fixed sub-magnet members, a magnetic member is provided on the surface of the main permanent magnet member via a non-magnetic material, and the yoke and the magnet We adopted the technical means of forming a magnetic short circuit by the members and obtaining the magnetic force balance of both magnets.

Further, in the present invention, it is more preferable that the direction of the cylindrical hole is made into N and S alternating multipoles. Furthermore, in the present invention, a plurality of the magnetic circuit structures may be provided.

[0007]

According to the above construction, even when an unbalanced magnetic force is generated between the main magnet member and the sub magnet member during non-excitation,
Since the short circuit is formed by the magnetic member provided on the main magnet member, it is possible to prevent undesired magnetic flux from flowing to the attracted object, and thus to quickly remove the attracted object.

The magnetic attraction force F and the magnetic circuit have a relationship of F∝B ² × S, where B is the magnetic flux density of the magnetic attraction surface and S is the area. When it is increased, the suction force F is increased by its square. On the other hand, the magnetic flux density B is determined by the demagnetization curve of the permanent magnet and the operating point Pc of the permanent magnet.
Since the magnetic flux density Bd is proportional to the effective magnetic flux density Bd determined by the intersection point P with, the operating point Pc of the permanent magnet must be increased in order to improve the magnetic flux density B, as shown in FIG.
The operating point Pc of the permanent magnet has an anisotropic length Lm,
If the area orthogonal to the anisotropic direction is Am, then Pc∝Lm
Therefore, if the length Lm in the anisotropic direction is constant, the operating point Pc can be reduced by decreasing the area Am.
Can be higher. That is, the operating point Pc is improved, the effective magnetic flux density Bd is improved, the magnetic flux density B on the magnetic attraction surface is improved, and the attraction force F can be increased by increasing the number of poles of the permanent magnet as in the above-described configuration. .

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention is shown in FIGS. The steel material hoisting device in each figure has a magnetic circuit part 1 and a substrate 3 that supports the magnetic circuit part 1 via a magnetic blocking plate 2 made of a non-magnetic material and has a hanging metal part 4, which are It is integrally assembled by the bolt 5 (shown in FIG. 3). The magnetic circuit unit 1 has a pair of yokes 7a and 7b made of a ferromagnetic material (iron, steel, etc.) having attraction surfaces 6a and 6b, respectively.
And non-magnetic spacers 8a, 8 installed between them
b, the yokes 7a and 7b, and the spacer 8
In a hole 9 formed between a and 8b, a permanent magnet 11 for rotation, a non-magnetic plate 12 mounted parallel to the magnetizing direction of the magnet, and a magnetic member 13 mounted on the non-magnetic plate. The main magnet member 10 is formed. A sub-magnet member 14 composed of a block-shaped permanent magnet magnetized in the left-right direction of the paper is installed above the non-magnetic spacer 8a.

FIG. 1 shows a state in which the object to be attracted 30 is attracted to the yokes 7a and 7b. The main magnet member 10 and the sub magnet member 14 are in the state of the S pole on the yoke 7a side and the N pole on the yoke 7b side, respectively. . The magnetic fluxes 20a, 20b, 20c generated by the sub-magnet member 14 pass through the object to be attracted 30 via the yoke 7b and the attracting surface 6b, and then the attracting surface 6a and the yoke 7a.
After that, it returns to the sub-magnet member 14. Since the main magnet member 10 has the same magnetization direction as the sub magnet member 14, the main magnet member 1
The magnetic fluxes 20d and 20e generated by the
Since it flows through the same magnetic path as the magnetic flux generated by, the main magnet member 10 in FIG. 1 functions to increase the attractive force.
At this time, as shown in FIG. 1, the magnetic member 13 is the non-magnetic plate 1.
2 and the non-magnetic spacer 8b, the width (w) of which is narrower than that of the non-magnetic spacer 8b.
Since it does not contact with a and 7b and is not involved in the magnetic circuit, magnetic force loss (decrease in adsorption force) does not occur.

Next, when removing the object to be attracted 30, the main magnet member 10 is rotated by 180 ° by a lever (not shown) interlocking with the main magnet member 10. That is, as shown in FIG. 2, the main magnet member 10 is rotated 180 ° from the state of FIG.
The magnetic flux generated by the auxiliary magnet member 14 and the main magnet member 10 forms a closed circuit in the magnetic circuit 1 with the side being the S pole. However, if the magnetic force balance between the main magnet member 10 and the sub magnet member 14 is biased, a part of the magnetic flux will be absorbed by the object 3 to be attracted.
Since it passes 0, it is not possible to easily remove the object 30 to be adsorbed.

Therefore, in the present invention, when there is a magnetic force difference between the main magnet member 10 and the sub magnet member 14 during non-excitation, the difference forms a magnetic short circuit by the yokes 7a and 7b and the magnetic member 13. The magnetic circuit structure is such that magnetic force balance can be obtained and the object to be attracted 30 can be easily removed. FIG. 2 shows an example in which the magnetic force of the sub magnet member 14 is larger than that of the main magnet member 10, and the difference between the sub magnet member 14 and the main magnet member 10 represents a state in which the magnetic circuit structure 20c is formed and the magnetic force is balanced.

Further, by increasing the number of poles in the main magnet member 10 in the axial direction, the attracting force can be increased, and in any of the above-mentioned embodiments, a plurality of similar magnetic circuit structures are provided (not shown). , The adsorption power is remarkably increased, and a better effect is obtained.

[0014]

As described above, according to the present invention, a magnetic member is provided on the surface along the magnetization direction of the main magnet member, and a short circuit is formed by the yoke and the magnetic member. It is possible to obtain a mutual magnetic force balance, and therefore, the magnetic flux generated by the magnetic force difference between the main magnet member and the sub magnet member does not pass through the attracted object during non-excitation, which facilitates the removal work of the attracted object. Can be done.

[Brief description of drawings]

FIG. 1 is a front view of a lifting device according to an embodiment of the present invention, showing a suction state.

FIG. 2 is a front view of the lifting device according to the embodiment of the present invention, showing a non-adsorption state.

FIG. 3 is a front view (a) and a cross-sectional view (b) taken along the line AA of the conventional lifting device.

FIG. 4 is a diagram showing a demagnetization curve of a permanent magnet.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Magnetic circuit part, 2 ... Magnetic blocking plate, 3 ... Substrate, 4 ... Hanging metal fitting part, 5 ... Bolt, 6a, 6b ... Adsorption surface, 7a, 7b ...
Yoke, 8a, 8b ... Non-magnetic spacer, 9 ... Hole, 10
... Main magnet member, 11 ... Permanent magnet for rotation, 11a, 11b
... Part of the surface of the permanent magnet for rotation, 12 ... Nonmagnetic plate, 13
... Magnetic member, 14 ... Sub-magnet member, 20a, 20b, 20
c, 20d, 20e ... magnetic flux, 30 ... object to be adsorbed

Claims (3)

[Claims] 1. A yoke member having a cylindrical hole at approximately the center of a pair of yokes facing each other with a spacer made of a non-magnetic material and each having an attracting surface, and rotatably disposed in the hole. Steel material having a magnetic circuit structure composed of a main permanent magnet member having a magnetic pole in the radial direction and a sub magnet member having a magnetic pole corresponding to the polarity of the main permanent magnet member and magnetized and fixed in the thickness direction. In the hoisting device, a magnetic member may be provided on the surface of the main permanent magnet member via a non-magnetic body, and a magnetic short circuit may be formed by the yoke and the magnetic member during non-excitation to obtain a magnetic force balance between both magnets. A steel material lifting device characterized by being able to do so. 2. The steel material hoisting device according to claim 1, wherein the cylindrical hole direction is multipolar with N and S alternating. 3. A steel material hoisting device comprising a plurality of magnetic circuit structures according to claim 1 or 2.