JPS6165740A - Permanent electromagnetic type attractive mounting device - Google Patents

Abstract

PURPOSE:To eliminate the necessity for high accurate control of an electric current applied to a device, hold its attractive force to a high level and reduce a leak of magnetic flux to zero in the device when it is not in operation, by forming the device such that magnets of small and large coercive force are magnetized in an equal direction when a magnetic material is attractively mounted while in a reverse direction when the magnetic material is not attractively mounted. CONSTITUTION:When a magnetic material 6 is attractively mounted, a DC electric current is applied to an excitation coil 2, and if a magnetizing direction of an alnico magnet 1 is equalized to that of a ferrite magnet 3, a device, forming a magnetic path M1, magnet 1 magnetic pole piece 4 magnetic material 6 yoke cup 5 magnet 1, and a magnetic path M2, magnet 3 magnetic pole piece 4 magnetic material 6 cup 5 magnet 3, strongly attracts the magnetic material 6 to be mounted, maintaining the magnetic path even if electrification is interrupted. Next, a DC electric current in a reverse direction is applied to the coil 2 by switching a selector switch 9, and if the magnetizing direction of the magnet 1 is reversed to that of the magnet 3 while the magnetic force of the set of magnets 1, 3 is equalized, the device, rendering no service to the magnetic material 6 by the magnetic force of the magnets 1, 3 of two kinds and easily maintaining a magnetic path M3 by the magnetic material 6, completely prevents magnetic flux from leaking to the outside.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Application This invention relates to an improvement in a permanent electromagnetic attracting device that has a permanent magnet and an excitation coil and performs magnetic attracting and releasing.

BACKGROUND ART In general, lifting magnets, brakes, clutches, chucks, etc. that utilize magnetic attraction and attraction are widely used.Today, due to the need to save power, torpedoes rely only on the magnetic force of permanent magnets to maintain the attraction state. Mold adsorption device (hereinafter referred to as
(simply referred to as an adsorption device) has been put into practical use.

Such an adsorption device consists of a permanent magnet, an excitation coil, a magnetic pole piece, and a yoke. To explain this using the example of a typical lifting magnet, the excitation coil is locally attached to an alnico permanent magnet, and the excitation coil is attached to one end of the permanent magnet. A magnetic pole piece is attached, and a yoke cup is attached to the other end of the permanent magnet, and the magnetic material is magnetically attracted to the open end surface of the 141 pole piece and the yoke cup,
A DC current is applied to the excitation coil to magnetize the permanent magnet at the same time as magnetic attraction, and when the magnetic material is released, a DC current in the opposite direction to that during attraction is applied to the excitation coil to almost demagnetize the permanent magnet. Keep it in that state.

In addition, in the same configuration as above, a permanent magnet with a high coercive force such as a ferrite magnet that has been magnetized in advance is used, and an excitation coil is arranged around the magnetic pole piece, so that the magnetic body is brought close to the magnetic pole piece and attracted. When released, the excitation coil is energized to temporarily cancel out the magnetic attraction force of the permanent magnet.

In this way, in the above-mentioned conventional configuration, the DC current applied at the time of release is applied to a very narrow channel in order to demagnetize the permanent magnet or temporarily cancel the magnetic attraction force of the permanent magnet to prevent the magnetic material from re-adsorbing. The current must be controlled within a certain range, and in the non-operating state, the former is not necessarily in a completely demagnetized state, and in the latter case, the magnetic flux always leaks to the outside, and both create unnecessary adsorption force. There was a problem that could lead to an unexpected attack.

Therefore, in view of the current state of the adsorption device, the applicant has proposed a system that does not require high precision in controlling the current applied to the excitation coil.
We proposed an easy-to-handle torpedo magnetic type adsorption device that has strong magnetic attraction and adsorption force, and has no Φ leakage magnetic flux when not in operation.
No. 8-238648).

That is, in the above proposed invention, on the other side of the magnetic pole piece, one side of which is the attracting surface, the remaining permanent magnet and at least the low coercive force magnet are centered on either a high coercive force magnet or a low coercive force magnet. An excitation coil capable of exerting a magnetic flux on the magnet is arranged in parallel or around the magnet, the magnetic pole piece is covered with a yoke cup so that its attracting surface is exposed, and the inner surface of the yoke cup is connected to at least the other end of the permanent magnet. This is a torpedo magnetic type attraction device in which a low coercive force magnet is magnetized in the same direction as a high coercive force magnet when a magnetic material is attracted, and a low coercive force magnet is magnetized in the opposite direction to a high coercive force magnet when a magnetic material is not attracted. be.

In this configuration, when the magnetic material is not attracted, the magnetization directions of the low coercive force magnet and the high coercive force magnet are reversed to form a magnetic path between the pair of magnets, thereby reducing the leakage magnetic flux density to the outside of the attracting device. It becomes possible to eliminate. However, in order to completely reduce the leakage magnetic flux to zero, it is necessary to make the magnetic forces of the low coercive force magnet and the high coercive force magnet the same, and to make the magnetic fluxes generated from both magnets equal.

In practical terms, the magnetic properties, shape,
Due to variations in dimensions and current applied to the excitation coil, etc.
Adjusting the magnetic fluxes of the pair of magnets to be equal has many manufacturing problems. For example, it is necessary to take into account that the magnetic properties of the magnets vary by about 10% even if the dimensions are exactly the same.

Therefore, in the above-mentioned adsorption device, even a small amount of leakage magnetic flux from the device when not adsorbing causes unnecessary magnetic material to be adsorbed to the adsorption surface, and when the adsorption device is in operation, the unnecessary magnetic material is mixed with the adsorbed object. This means that there is a possibility that the particles may be interposed between the particles, forming substantial voids, significantly reducing the adsorption force, and causing safety problems.

Purpose of the Invention The present invention provides a torpedo magnetic attraction device that has a strong magnetic attraction force without requiring high precision in controlling the current applied to the excitation coil, and substantially reduces leakage magnetic flux when not in operation. The aim is to create a torpedo magnetic adsorption device that is zero, easy to maintain, and has excellent safety.

Structure and Effects of the Invention The present invention provides a magnetic pole piece on the other side of which one side is an attraction surface.
The remaining permanent magnet and an excitation coil capable of exerting magnetic flux at least on the low coercive force magnet are arranged in parallel or around one of the 8 coercive force magnets and the low coercive force magnet. A power supply circuit which is enclosed in a yoke cup so that its attraction surface is exposed, and which connects the inner surface of the yoke cup to at least the other end of the permanent magnet, and further has an excitation direction changeover switch between the excitation coil and the DC power source. The power supply circuit when a magnetic material is not attracted has a configuration in which a resistance is provided to make the magnetic forces of the low coercive force magnet and the high coercive force magnet equal to each other when they are magnetized in at least mutually opposite directions. This is a torpedo magnetic attraction device in which a magnetic force magnet is magnetized in the same direction as a high coercive force magnet, and a low coercive force magnet is magnetized in the opposite direction to the high coercive force magnet when not attracted.

In this invention, the high coercive force magnet and the low coercive force magnet include single permanent magnets such as cylindrical, prismatic, or ring-shaped permanent magnets, as well as a plurality of magnets combined into the above shape or small-sized magnets. A low coercive force magnet is a magnet with a coercive force whose direction of magnetization can be easily reversed by magnetizing an excitation coil, and for example, alnico permanent magnets are often used. ,Also,
The high coercive force magnet is preferably a ferrite permanent magnet N'+a rare earth permanent magnet that is not affected by the magnetization of the excitation coil.

Also, the difference in coercive force between a high coercive force magnet and a low coercive force magnet is that when the low coercive force magnet reverses its magnetization direction, it is affected by the magnetic field of the excitation coil, resulting in a high coercive force of 1! 'h It is necessary that the magnetic force of the magnet does not decrease, and the high coercive force magnet is preferably 3 times or more that of the low coercive force magnet, and in particular, by making it 5 times or more, the advantage is that the permissible range of the current value applied to the excitation coil is expanded. There is.

In this invention, the island coercive force magnet, low coercive force magnet, and excitation coil are arranged by arranging rectangular parallelepiped block magnets in parallel around one of the permanent magnets, or by arranging the excitation coil around a cylindrical or prismatic magnet. Depending on the shape and weight of the object to be attracted, two types of magnets are available, such as arranging coils and magnets in a ring shape, or arranging multiple prismatic magnets at regular intervals around a central permanent magnet. Arrangement configuration of permanent magnets and excitation coils, magnetic properties and shape dimensions of permanent magnets, magnetizing force of excitation coils,
The shape of the yoke cup and the magnetic pole piece may be selected as appropriate.

In addition, the excitation coil may be placed around the low coercive force magnet so that its magnetic flux can act on at least the low coercive force magnet, and may be placed directly around the low coercive force magnet, or may be placed around the outermost periphery of the low coercive force magnet. , or may be arranged around a part of the back of the axial height of the permanent magnet.

In addition, the yoke cup has two types of permanent magnets and an excitation coil arranged on the plane of the magnetic pole piece, and is encapsulated so that at least the other surface of the permanent magnet and the inner surface of the yoke cup are connected to form a magnetic path. For example, in addition to the one that covers the whole part, there are various shapes such as a yoke cup with a structure in which a cross-shaped member is bent so that each tip is lined up as a leg part on the same plane as the attracting surface of the magnetic pole piece. Available.

In the adsorption device according to the present invention, for adsorption and release, it is only necessary to apply current to the excitation coil at the time of starting the device, and there is no need to maintain the application.Two types of permanent magnets are also involved in the magnetic force at the time of adsorption, so the adsorption force is is strong, and there is no leakage magnetic flux after release, making release easy.

The current applied to the excitation coil during attraction should be sufficient to magnetize the low coercive force magnet in the same direction as the high coercive force magnet. In particular, by completely magnetizing the low coercive force magnet, Magnetic force can be used effectively.

In addition, the current applied to the excitation coil at the time of release is determined by the need to equalize the magnetic force of the low coercive force magnet and the high coercive force magnet.
In order to magnetize the low coercive force magnet and the high coercive force magnet to the same magnetic force, a resistor is installed (for example, a variable It is necessary to set the required resistance directly in advance with a resistor.In other words, this resistor ensures that even if more current than necessary is supplied from the power supply, a constant amount of current is applied to the excitation coil, and the low coercive force is maintained. The amount of magnetization of the magnet is also constant. Therefore, in this invention, the magnetic force of the high coercive force magnet is
It is desirable to set the magnetic force slightly lower than the magnetic force of a low coercive force magnet when it is completely magnetized.

In addition, the resistor is designed so that its resistance value can be easily set.
A variable resistor is preferable, and in addition to setting the resistance value according to variations in the magnetic force of the magnet, it is also possible to select a fixed resistor with a resistance value according to variations in magnetic force, etc. during the final adjustment of the adsorption device after manufacturing is completed. good.

Further, the adsorption device according to the present invention can be used not only as a lifting magnet but also as a brake, a clutch, a chuck, and the like.

EXAMPLES Below, an adsorption device according to the present invention will be explained based on the drawings. Here, an example of a lifting magnet using a ferrite magnet as a high coercive force magnet and an alnico magnet as a low coercive force magnet will be described. FIGS. 1 and 2 are longitudinal sectional views of a torpedo magnetic type adsorption device according to the present invention.

In the example shown in Fig. 1, an excitation coil (2) is arranged around a cylindrical alnico magnet (1) that is a low coercive force magnet, and a ring-shaped ferrite magnet that is a high coercive force magnet is placed around the outer periphery of the coil (21). (3) is placed on the flat surface of the disk-shaped magnetic pole piece (4) having a ring protrusion, and the magnet is placed.

It consists of a cup-shaped yoke cup (5) connected to the other end of the coil.

Furthermore, a power supply circuit including an excitation coil (2) and a DC Ti source (power and an excitation direction switch (9)) is attached, and the power supply circuit, which is open when not attracted, is connected to an alnico magnet (1) and a ferrite magnet ( 3) A variable resistor (8) is connected in parallel to make the magnetic force equal to the magnetization.

When attracting the magnetic material (6), apply direct current to the excitation coil ('2J) to completely magnetize the alnico magnet (1), and change the magnetization direction of the alnico magnet (1) to the ferrite magnet (3). , as shown in Figure 1A, Alnico magnet (1) → magnetic pole piece (4) → magnetic body (6) → yoke cup (
5) → Magnetic path (M+) of alnico magnet (1) and ferrite magnet (3) → magnetic pole piece (4) → magnetic body (6) → yoke cup (5) → magnetic path of ferrite magnet (3) (M2)
Two magnetic paths are formed to strongly attract the magnetic material (6). Furthermore, even if the excitation coil (2) is de-energized, the magnetic path is maintained.

Next, when releasing, switch the changeover switch (9) and
Apply a direct current in the opposite direction to the excitation coil +2 to change the magnetization direction of the alnico magnet (1) to the ferrite magnet (3).
) and make the magnetic forces of the pair of magnets (1) and (3) the same, the alnico magnet (
1) → Yoke cup (5) → Ferrite magnet (3) → Pole piece (4) → Alnico magnet (1) A magnetic path (M3) is formed, and the magnetic force of the two types of magnets (1) and (3) is a magnetic material (6)
The magnetic material (6) is easily released without making any contribution to the magnetic field.

Furthermore, even if the excitation coil (2) is de-energized, the above magnetic path (M3) is maintained, leakage magnetic flux to the outside is completely eliminated, and unnecessary attraction force is not generated.

By the way, alnico magnets and ferrite magnets are used in the configuration shown in Figure 1 above, and the excitation coil has a magnetomotive force of 1000 (
A-T> was placed, the resistance was set to the optimum value, and the magnetic material was attracted and released. Strong adsorption and easy and smooth release were obtained, and leakage of magnetic flux to the outside was prevented. There wasn't any.

In the example shown in Figure 2, a ring-shaped alnico magnet (1) is arranged around a cylindrical ferrite magnet (3), an excitation coil (2) is arranged around the outer periphery, and a disc-shaped magnet with a ring projection is arranged. Pole piece (4) Place the magnet on a flat surface.

It consists of a cup-shaped yoke cup (5) connected to the other end of the coil, and the central ferrite magnet (3) is lower than the surrounding alnico magnets (1), and the yoke cup is lower by the lower part. (5) A protrusion is provided in the center.

In addition, a power supply circuit is attached to the excitation coil (a) and a DC power supply (power), which has an excitation direction switch (9).
A variable resistor (8) for maintaining the same magnetic force of the alnico magnet (1) and the ferrite magnet (3) is connected in parallel to the power supply circuit that is open when not attracted.

In the above configuration, the action and operation of attracting and releasing the magnetic body (6) are exactly the same as those described in FIG. The effects such as easy and simple release and no leakage magnetic flux after release are the same.

[Brief explanation of the drawing]

FIGS. 1 and 2 are longitudinal sectional views of a torpedo magnetic type adsorption device according to the present invention. 1... Al, Nico magnet, 2... Excitation coil, 3...
- Ferrite magnet, 4... Magnetic pole piece, 5... Yoke cup, 6... Magnetic material, 7... DC power supply, 8... Variable resistor, 9... Changeover switch. Figure 1 Figure 2

Claims (1)

[Claims] 1. On the other side of the magnetic pole piece, one side of which is an attractive surface, a low coercive force magnet and an excitation coil capable of exerting magnetic flux at least on the low coercive force magnet are arranged in parallel with the high coercive force magnet at the center. A power source that connects at least the other end of the permanent magnet to the inner surface of a yoke cup that is arranged or arranged around the magnetic pole piece so that its attracting surface is exposed, and that has an excitation direction changeover switch between the excitation coil and the DC power source. When the circuit is not attracted, the power supply circuit has a configuration in which a resistance is provided to make the magnetic force of the low coercive force magnet and the high coercive force magnet the same when they are magnetized at least in mutually opposite directions. A permanent electromagnetic attraction device in which a coercive force magnet is magnetized in the same direction as a high coercive force magnet, and a low coercive force magnet is magnetized in the opposite direction to the high coercive force magnet when not attracted. 2. On the other surface of the magnetic pole piece, one surface of which is an attractive surface, a high coercive force magnet and an excitation coil that exerts magnetic flux on the low coercive force magnet are arranged in parallel or around the low coercive force magnet,
A power source for a power supply circuit when not attracted, which connects at least the other end of the permanent magnet to the inner surface of a yoke cup enclosing a magnetic pole piece so that its attraction surface is exposed, and has an excitation direction switching switch between an excitation coil and a DC power source. The circuit has a configuration in which a resistance is provided in the circuit to make the magnetic force the same when a low coercive force magnet and a high coercive force magnet are magnetized at least in mutually opposite directions. A permanent electromagnetic attraction device that is magnetized in the same direction as the magnet, and when not attracted, a low coercive force magnet is magnetized in the opposite direction to a high coercive force magnet.