WO2022169029A1 - Magnet holder and magnetic drill comprising same - Google Patents

Abstract

The present invention provides a magnet holder which can be moved easily even after release. Provided in one embodiment is the magnet holder comprising: a fixed-type permanent magnet extended in one direction; a rotating-type permanent magnet extended in the one direction and having both ends rotatably fixed; a first yoke and a second yoke covering both lateral surfaces of the fixed-type permanent magnet and the rotating-type permanent magnet, and extended in the vertical direction; and coils which are respectively wound around the first and second yokes. On a cross-section perpendicular to the one direction, the first yoke comes into contact with the N pole of the fixed-type permanent magnet, the second yoke comes into contact with the S pole of the fixed-type permanent magnet, and the coils, the rotating-type permanent magnet and the fixed-type permanent magnet are positioned consecutively along the first and second yokes from an attachment surface of an object to be attached to which the first and second yokes are attached.

Description

Magnetic holder and magnetic drill including same

The present invention relates to a magnetic holder and a magnetic drill including the same.

A magnetic holder is a device for attaching an attachment target made of a magnetic material using magnetic force, and is used in various holding devices, machine tools, and the like.

This magnetic holder basically attaches a magnetic object to an attachment by using the strong magnetic force of a permanent magnet. do.

Patent Document 1 discloses a magnetic drill to which such a magnetic holder is applied. In the case of a magnetic drill including a magnetic holder as in Patent Document 1, it is a manual type and has the advantage that no power is required to fix the drill, but it is inconvenient to use, and in particular, even when released, force must be applied due to residual magnetization. There is a problem of falling from the attachment target.

Patent Document 1

US 9,452,521 B2 (2016.9.27 Announcement)

The present invention is to solve the problems of the prior art as described above, and an object of the present invention is to provide a magnetic holder that is easy to fasten and release, and which is easy to move even after release, and a magnetic drill including the same.

The present invention provides a magnetic holder and a portable magnetic drill as follows in order to achieve the above object.

The present invention in one embodiment a fixed permanent magnet extending in one direction; a rotatable permanent magnet extending in the one direction and having both ends rotatably fixed; first and second yokes covering both sides of the fixed permanent magnet and the rotating permanent magnet and extending in the vertical direction; and a coil wound around the first and second yokes, in a cross-section perpendicular to the one direction, the first yoke is in contact with the N pole of the fixed permanent magnet, and the second yoke is the fixed permanent magnet. Provided is a magnetic holder in contact with the S pole and in which a coil, a rotating permanent magnet and a fixed permanent magnet are sequentially disposed along the first and second yokes from an attachment surface to which the first and second yokes are attached to an attachment object. .

In one embodiment, the first yoke and the second yoke include a groove to which the fixed permanent magnet is in close contact and a cover part surrounding the rotatable permanent magnet, and the rotatable permanent magnet includes a curved part and a straight part. The cover portion may include a curved surface having a radius of curvature greater than a radius of the curved portion of the rotatable permanent magnet.

In one embodiment, the radius of curvature of the curved surface of the cover is 0.1 to 0.6 mm larger than the maximum radius of the rotatable permanent magnet, and the radius of the radius of curvature of the curved surface of the cover is the same as the rotational center of the rotatable permanent magnet. can

In one embodiment, it may include an additional permanent magnet disposed at a position corresponding to the fixed permanent magnet or the rotating permanent magnet on the outer surface of each of the first and second yokes.

In one embodiment, the thickness of the additional permanent magnet may be less than or equal to the winding thickness of the coil.

In one embodiment, the first and second yokes include a permanent magnet yoke corresponding to the fixed permanent magnet and the rotating permanent magnet, and a coil unit yoke including an attachment surface from a portion on which the coil is wound, the permanent magnet The magnet yoke and the coil unit yoke may have a separable structure. In this case, the coil unit yoke may be configured to be separated and mounted to the permanent magnet yoke by a bolt fastened in a direction perpendicular to the attachment surface.

In one embodiment, the rotational permanent magnet is disposed at positions corresponding to both end surfaces in the one direction, further comprising a bracket fixed to the first and second yokes, the bracket having a shaft mounted thereon, A groove is formed in the typical permanent magnet, so that the rotating permanent magnet can be rotatably fixed to the shaft of the bracket.

The present invention is a drill unit; the magnetic holder described above; and a power supply unit for providing power to the drill unit and the magnetic holder, wherein the power supply unit may include a rechargeable battery.

The present invention can provide a magnetic holder that is easy to fasten and disengage, and which is easy to move even after release, and a magnetic drill including the same.

1 is a schematic diagram of a magnetic drill according to an embodiment of the present invention.

2 is a conceptual diagram of a magnetic holder according to an embodiment of the present invention.

3 is a perspective view of a magnetic holder according to an embodiment of the present invention.

4 is a cross-sectional view of a magnetic holder according to an embodiment of the present invention.

Fig. 5 is a schematic diagram showing the formation of a magnetic field in the magnetic holder of Fig. 4;

6 is a cross-sectional view of a rotating permanent magnet of a magnetic holder according to an embodiment of the present invention.

7 is a cross-sectional view of a first yoke of a magnetic holder according to an embodiment of the present invention.

8 is a cross-sectional view of a magnetic holder according to an embodiment of the present invention.

Fig. 9 is a schematic diagram showing the formation of a magnetic field in the magnetic holder of Fig. 8;

10 is a cross-sectional view of a magnetic holder according to an embodiment of the present invention.

Hereinafter, a specific embodiment of the present invention will be mainly described with reference to the accompanying drawings.

1 is a schematic diagram of a magnetic drill according to an embodiment of the present invention is shown.

As shown in Figure 1, the magnetic drill (1) is a body with a handle; a drill part 10 connected to one side of the main body and provided with a motor for driving a drill, a gear, etc.; It includes a power supply unit 20 for providing power to the drill unit 10 and a magnetic holder 30 for fixing the main body to an attachment target.

In the case of the drill unit 10 , since there is no difference from the conventional magnetic drill 1 , a detailed description is omitted, and the power supply unit 20 may include a rechargeable battery.

The magnetic holder 30 includes a fixed permanent magnet 31 , a rotating permanent magnet 32 , and a coil 35 (refer to FIG. 2 ) connected to the power supply unit 20 , and power supplied to the coil 35 . Depending on the direction, the magnetic holder 30 may or may not be operated. The configuration of the magnetic holder 30 will be described again in detail with reference to FIGS. 2 to 10 .

In this embodiment, the magnetic holder 30 is switched on/off by electricity supply without the need for a person to rotate the handle. Therefore, the user's force is not required and the operation is easy. In addition, power consumption can be reduced by switching operation/non-operation with an instantaneous current of about 0.3 to 0.5 seconds, so that the power supply unit 20 of limited capacity shared by the drill unit 10 and the magnetic holder 30 is used. It can be used more in the drill part 10, which can lead to an increase in the use time until charging.

In addition, since it uses a simple structure and a structure that is easy to disassemble and assemble, it is easy to repair or assemble, and it is possible to make the magnetic drill 1 compact because the space it occupies is small.

Furthermore, when the magnetic holder 30 does not operate, there is no residual magnetism, so that the user can use the magnetic force due to the magnetic force in addition to the weight of the magnetic drill 1 or the weight of the attachment object when the magnetic drill 1 is moved or the attachment object is removed. This addition may not be necessary, which may reduce the user's workload.

2 is a conceptual diagram of a magnetic holder 30 according to an embodiment of the present invention.

Figure 2 (a) shows a state when the magnetic holder 30 does not operate. In the case of the magnetic holder 30 of the present invention, a fixed permanent magnet 31 extending in one direction; a rotatable permanent magnet extending in the one direction and having both ends rotatably fixed; first and second yokes (33, 34) covering both sides of the fixed permanent magnet (31) and the rotating type permanent magnet (32) and extending in the vertical direction; and a coil (35) wound around the first and second yokes (33, 34), wherein, in a cross section perpendicular to the one direction, the first yoke (33) is the N pole of the fixed permanent magnet (31). In contact with, the second yoke 34 is in contact with the S pole of the fixed permanent magnet 31, and the first and second yokes 33 and 34 are attached to the attachment surface (O) 37), a coil 35, a rotating permanent magnet 32 and a stationary permanent magnet 31 are arranged one after another along the first and second yokes 33, 34.

As shown in Fig. 2 (a), the magnetic flow is formed through the first and second yokes 33 and 34 in the stationary permanent magnet 31 and the rotating permanent magnet 32 during non-operation. Since no current flows in the coil 35 , the rotating permanent magnet 32 is rotated so that the S pole faces the first yoke 33 and the N pole faces the second yoke 34 .

It is possible to rotate the rotating permanent magnet 32 by applying a current to the coil 35 in the non-operational state. The rotational permanent magnet 32 rotates by applying a current to the coil so that the upper portion of the coil 35 of the first yoke 33 becomes the S pole and the upper portion of the coil 35 of the second yoke 34 becomes the N pole. When applied as large as possible, the rotating permanent magnet 32 rotates, and when current application is blocked in this state, the magnetic field flow is formed to pass through the attachment surface 37 as shown in FIG. 2(b). The N poles of the fixed permanent magnet 31 and the rotating permanent magnet 32 are disposed toward the first yoke 33 , and the fixed permanent magnet 31 and the rotating permanent magnet 32 are directed toward the second yoke 34 . ) of the S pole is arranged.

Since the magnetic holder 1 is sufficient to use power only momentarily, it is possible to improve user convenience without burdening the rechargeable battery.

In particular, in the case of the magnetic drill (1), the user manually rotated the rotating magnet of the permanent magnet to fix it after moving it, but it was difficult to use an external power source, so a mechanical structure was used as in the prior art, It is effective to use power only momentarily when passing through the coil 35 , and it is also useful in that it does not require a separate user's effort for rotation.

In addition, the curvature of the curved surfaces formed in the first and second yokes 33 and 34 is greater than the maximum radius of the rotating permanent magnet 32 so that the rotational permanent magnet 32 can rotate smoothly due to the coil 35 . By forming a larger radius, a gap is formed between the rotating permanent magnet 32 and the curved surface. In the magnetic force transmission, since the gap acts as a resistance element in the magnetic force transmission, the gap is preferably in the range of 0.1 to 0.6 mm.

3 is a perspective view of a magnetic holder 30 according to an embodiment of the present invention.

As shown in FIG. 3 , the magnetic holder 30 has a first yoke 33 and a second yoke 34 disposed on the side thereof, and a permanent magnet 31 fixed to the first yoke 33 and the second yoke 34 . ) are arranged consecutively in a plurality along the longitudinal direction or arranged as one piece. A rotating permanent magnet 32 is disposed directly below the fixed permanent magnet 31 . The rotating permanent magnet 32 is formed in one piece.

Brackets 36 for rotatably supporting the rotatable permanent magnet 32 are disposed at both ends of the rotatable permanent magnet 32 in the longitudinal direction. The bracket 36 is bolted to the first and second yokes 33 and 34 , and a groove 36a and a bearing 36b are disposed at positions corresponding to the rotational axis of the rotating permanent magnet 32 . A rotating shaft may be inserted into the center of both ends of the rotating permanent magnet 32 , and the rotating shaft is inserted into the bearing 36b so that the rotating permanent magnet 32 is disposed between the first and second yokes 33 and 34 . can be rotated. The fixed permanent magnet 31 and the rotating permanent magnet 32 are arranged adjacent to each other, and are arranged close to each other within the limit not interfering with the rotation of the rotating permanent magnet 32 .

The coil 35 is disposed below the rotating permanent magnet 32 . The first yoke 33 and the second yoke 34 are not formed as a single piece, but may be configured separately from a portion on which the coil 35 is wound, as shown in FIG. 7 to be described later.

4 is a cross-sectional view of a magnetic holder according to an embodiment of the present invention is disclosed, FIG. 5 is a schematic diagram showing the formation of a magnetic field of the magnetic holder of FIG. 4, and FIG. 6 is a cross-sectional view of a rotating permanent magnet is shown.

4 and 6, the fixed permanent magnet 31 has a rectangular parallelepiped shape, and the rotating permanent magnet 32 is positioned between a pair of curved portions 32a having a constant radius of curvature and the coplanar portion 32a. It includes a flat portion (32b), and is provided with a rotation groove (32c) into which the rotation shaft is inserted at both ends. In the case of the rotating groove (32c), it is possible to be provided at both ends, and it is also possible to be composed of a single groove that completely penetrates the rotating permanent magnet (32).

In the first yoke 33, the permanent magnet yoke 33a is a surface facing the second yoke 34, and a groove 33c into which the fixed permanent magnet is fitted is formed, and the curved surface of the rotating permanent magnet 32 is formed underneath it. and a cover portion 33d covering the portion 32a. The upper and lower edges of the cover part 33d protrude from the groove 33c, and the central part is located further inside the groove 33c. The cover portion 33d is formed with a curved surface 33e between upper and lower edges, and the curved surface 33e has a greater radius of curvature R than the radius r of the curved portion 32a of the rotating permanent magnet 32 . ), the radius of curvature R of the cover portion 33d may be 0.1 to 0.6 mm greater than the radius r of the rotating permanent magnet 32 . The center of the radius r of the rotating permanent magnet 32 and the center of the radius of curvature R of the cover part 33d coincide with each other.

As shown in FIG. 5 , in the magnetic holder 30 when not in operation, the magnetic field formed by the rotating permanent magnet 32 and the fixed permanent magnet 31 hardly flows to the object.

7 is a cross-sectional view of the first yoke 33 of the magnetic holder 30 according to an embodiment of the present invention.

As shown in FIG. 7 , that is, the first yoke 33 includes a permanent magnet yoke 33a and a coil unit yoke 33b. The permanent magnet yoke 33a and the coil unit yoke 33b have a structure that can be coupled/separated by the bolt 35a, which facilitates disassembly and assembly during manufacturing and repair. In particular, there is no room for failure in the case of the permanent magnet, but in the case of the coil 35, problems such as disconnection may occur depending on use. According to the present invention, by arranging the coil 35 in the first and second yokes 33 and 34 at a position adjacent to the attachment surface 37, and applying a separable structure, workability is improved.

As shown in FIG. 7 , guide plates 35b may be disposed on the coil part yoke 33b and above/under the coil 35 on which the coil 35 is wound.

On the other hand, as shown in area A of FIG. 5 , some residual magnetism is transferred to the attachment target, which causes inconvenience in moving the machine after the operation is finished. In particular, it is very important to further reduce such residual magnetism in devices that require repeated fast and precise attachment and detachment, for example, a magnetic drill.

5, the magnetic holder 30 includes a fixed permanent magnet 31, a rotating permanent magnet 32, first and second yokes 33 and 34, and a rotating permanent magnet 32 and first and second yokes. (33, 34) is made by a complex correlation such as an air gap, it is difficult to analyze which configuration and how to combine in order to reduce the residual magnetism, and it is very difficult to further reduce the residual magnetism.

The inventor of the present invention has developed a method of attaching an additional permanent magnet to further reduce residual magnetism, and Figs. 8 and 9 schematically show a cross-sectional view of the magnetic holder and a magnetic field formed in the magnetic holder.

As shown in FIG. 8, the structure of the fixed permanent magnet 31, the rotating permanent magnet 32, the first yoke 33, the second yoke 34 and the coil 35 in the magnetic holder 30 of FIG. is the same as the structure of the magnetic holder 30 of FIG. 4, and thus a detailed description thereof will be omitted.

However, in the magnetic holder 30 of FIG. 8 , additional permanent magnets 36 are respectively disposed at a height corresponding to the rotational permanent magnets 32 on the outer surfaces of the first and second yokes 34 . The additional permanent magnets 36 have a thinner thickness than the fixed permanent magnets 31 , and each of the additional permanent magnets 36 is disposed to face the same polarity as the fixed permanent magnets 31 in a plan view. That is, the additional permanent magnets 36 are disposed to face the poles different from those of the rotational permanent magnets 32 .

As shown in FIG. 9 by the additional permanent magnet 36, the residual magnetism is not transmitted to the attachment target, so the user does not have any difficulty in moving the machine after the operation is finished, and the magnetic need to repeat fast and precise attachment and detachment. It is more useful in drilling equipment.

The thickness of the additional permanent magnet 36 may be formed to correspond to or thinner than the winding thickness of the coil 35, which increases the volume due to the additional permanent magnet 36 when the case 37 is covered. may not bring

The additional permanent magnet (36) is a first of a magnetic holder (30) having a stationary permanent magnet (31), a rotating permanent magnet (32), a first yoke (33), a second yoke (34) and a coil (35). And since it can be attached to the outside of the structure of the second yoke (33, 34), it is possible to design the maximum magnetic force by the basic structure except for the additional permanent magnet (36), and to remove the residual magnetism with the additional permanent magnet (36) do.

FIG. 10 shows a modified example of the magnetic holder of the embodiment of FIG. 8 . In FIG. 10, the structures of the fixed permanent magnet 31, the rotating permanent magnet 32, the first yoke 33, the second yoke 34 and the coil 35 are shown in FIG. 8 and the magnetic holder 30 of FIG. is substantially the same as the structure of

In FIG. 10, the first yoke 33 and the second yoke 34 have a separate coil winding part, which is the same as the embodiment of FIG. 7, and the positions of the additional permanent magnets 36 are the first and second yokes ( Additional permanent magnets 36 are respectively disposed at a height corresponding to the fixed permanent magnets 31 on the outer surface of the 34 . As in FIG. 8 , the additional permanent magnets 36 have a thinner thickness than the fixed permanent magnets 31 , and the additional permanent magnets 36 have the same polarity as the fixed permanent magnets 31 and are disposed to face each other.

Even in the case of FIG. 10 , the same magnetic flow as in FIG. 8 is exhibited, so that residual magnetism is not transmitted to the attachment target.

Example 1

The first and second yokes 33 and 34 having the same cross section as in FIG. 7 , the rotating permanent magnet 32 having the same cross section as the cross section of FIG. 6 and having a volume of about 43,000 mm 3 , and about 36,000 mm 3 . An experiment was conducted with a magnetic holder 30 having a fixed permanent magnet 31 having a volume of . In this magnetic holder 30, the difference in the attraction force due to the gap between the curved surface portion 32a of the rotating permanent magnet 32 and the curved surface 33e of the cover portion 33d is summarized in Table 1, Rotational torque due to the gap, magnetic force, torque reduction rate, and magnetic force reduction rate are summarized. The above experimental results, ie, rotational torque and magnetic force, may be changed according to the size/shape of the yoke and permanent magnet to be tested, but the tendency of the torque reduction rate and magnetic force reduction rate according to the interval is maintained.

Thickness (mm)	Adsorption force (N)
	movement	non-moving
0.1	9256	38.5
0.2	9150	34.8
0.4	9023	28.8
0.6	8992	23.6
0.8	8785	21.0
1.0	8556	18.1

Thickness (mm)	Rotational torque (Nm)	torque ratio (Measured rotational torque / rotational torque when the interval is 0mm)	Magnetic force (N)	magnetic force ratio (Measured magnetic force / magnetic force when the distance is 0mm)
0	45.8	1.0	9,718	1.00
0.1	36.2	0.79	9,256	0.95
0.2	34.8	0.76	9,150	0.94
0.4	33.6	0.73	9,023	0.93
0.6	32.5	0.71	8,992	0.93
0.8	31.3	0.68	8,785	0.90
1.0	30.2	0.66	8,556	0.88

As shown in Tables 1 and 2, when the gap is small, the adsorption force is strong, but the torque for the rotation of the rotating permanent magnet 32 is increased, so that a large current is required, so that a lot of power supply 30 of the magnetic drill 1 It was unsuitable by giving a load, and 0.1 mm or more was preferable for smooth rotation. If it exceeds 0.6 mm, the adsorption force during operation is weakened, which is insufficient to fix the magnetic drill (1). In the case of a magnetic drill, since a compact structure is essential, there is a limitation that a large-sized electromagnet coil cannot be used to generate excessive rotational torque.

On the other hand, the magnetic force was 8,992N when there was an upper and lower edge protruding from the groove 33c in the cover part 33d having an interval of 0.6mm, but 8,362N when there was no upper and lower edge, 7% when the edge was missing A degree of magnetic force reduction occurred.

Example 2

The first and second yokes 33 and 34 having the same cross section as in FIG. 7 , the rotating permanent magnet 32 having the same cross section as the cross section of FIG. 6 and having a volume of about 48,000 mm 3 , and about 44,000 mm 3 . An additional permanent magnet 36 was attached to the magnetic holder 30 having a fixed permanent magnet 31 having a volume of , and the thickness of the additional permanent magnet 36 was changed. The magnet grades of the stationary permanent magnet 31, the rotating permanent magnet 32 and the additional permanent magnet 36 were the same as Nd50. The additional permanent magnets 36 were 13.5 mm wide and 50 mm long, and were attached two each on each side, and the experiment was conducted while only changing the thickness.

additional magnet thickness	1mm	2mm	3mm	4mm	5mm	doesn't exist
residual magnetism	4.2N	1.5N	0.95N	2.66N	6.45N	9.15N

As can be seen in Table 3, by adjusting the thickness of the additional permanent magnet 36, the residual magnetism can be reduced, so that the yokes 33 and 34 and the permanent magnet ( 31, 32) is easy to design. In particular, it is expected to be more advantageous for actual products in that it can respond to changes in magnetic force due to manufacturing tolerances.

Although the above description has been focused on the embodiments of the present invention, the present invention is not limited thereto and may be implemented with various modifications.

Claims (10)

1. Fixed permanent magnets extending in one direction;

   a rotatable permanent magnet extending in the one direction and having both ends rotatably fixed;

   first and second yokes covering both sides of the fixed permanent magnet and the rotating permanent magnet and extending in the vertical direction; and

   and a coil wound around the first and second yokes,

   In a cross section perpendicular to the one direction, the first yoke is in contact with the N pole of the fixed permanent magnet, and the second yoke is in contact with the S pole of the fixed permanent magnet,

   A magnetic holder in which a coil, a rotating permanent magnet and a fixed permanent magnet are sequentially disposed along the first and second yokes from an attachment surface to which the first and second yokes are attached to an attachment object.
2. The method of claim 1,

   The first yoke and the second yoke are

   a groove to which the fixed permanent magnet is in close contact; and

   It includes a cover part surrounding the rotating permanent magnet,

   The rotating permanent magnet includes a curved portion and a straight portion.

   and the cover portion includes a curved surface having a radius of curvature greater than a radius of the curved portion of the rotating permanent magnet.
3. 3. The method of claim 2,

   The radius of curvature of the curved surface of the cover is 0.1 to 0.6 mm larger than the radius of the rotating permanent magnet,

   The magnetic holder, characterized in that the radius center of the radius of curvature of the curved surface of the cover is the same as the radius center of the rotating permanent magnet.
4. 4. The method of claim 3,

   In the cross section perpendicular to the one direction, edges protruding from the groove are formed on upper and lower sides of the curved surface of the cover part.
5. The method of claim 1,

   and an additional permanent magnet disposed on an outer surface of each of the first and second yokes at positions corresponding to the fixed permanent magnets or the rotational permanent magnets.
6. 6. The method of claim 5,

   The thickness of the additional permanent magnet is a magnetic holder, characterized in that less than the winding thickness of the coil.
7. The method of claim 1,

   The first and second yokes include a permanent magnet yoke corresponding to the fixed permanent magnet and the rotating permanent magnet, and a coil unit yoke including an attachment surface from a portion on which the coil is wound,

   The magnetic holder, characterized in that the permanent magnet yoke and the coil unit yoke is a separable structure.
8. 8. The method of claim 7,

   The magnetic holder, characterized in that the coil unit yoke is configured to be separated and mounted on the permanent magnet yoke by a bolt fastened in a direction perpendicular to the attachment surface.
9. The method of claim 1,

   and a bracket disposed at positions corresponding to both end surfaces of the rotatable permanent magnet in one direction and fixed to the first and second yokes,

   and a shaft is mounted to the bracket, and a groove is formed in the rotatable permanent magnet, so that the rotatable permanent magnet is rotatably fixed to the shaft of the bracket.
10. drill unit;

    10. A magnetic holder according to any one of claims 1 to 9; and

    Includes; a power supply for providing power to the drill unit and the magnetic holder,

    The power supply is a portable magnetic drill including a rechargeable battery.

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