JP2608002B2 - Magnet chuck - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic chuck for fixing a soft magnetic material using magnetic attraction.

[0002]

2. Description of the Related Art FIGS. 11 and 12 are schematic end views of a conventional rotary operation type magnetic chuck. FIG. 11 shows a suction state and FIG. 12 shows a non-suction state. Reference numeral 1 denotes a material to be adsorbed by a soft magnetic material, and a through hole is formed at the center of a pair of soft magnetic materials yokes 4 opposed to each other with a non-magnetic material 3 having a magnetic insulating ability interposed therebetween.
The magnet chuck M formed by rotatably inserting the permanent magnet 2 can be in close contact with the attraction surfaces 40 and 41. FIG. 11 shows the attracted state, in which the magnetic flux from the N pole flows through the soft magnetic material 4, the attracting surface 40, the material to be attracted 1, the attracting surface 41, the soft magnetic material 4, and the S pole to form a closed magnetic path. Therefore, the adsorption surfaces 40 and 41 and the adsorption target material 1 are adsorbed. FIG. 12 shows a non-adsorbed state, in which the magnet 2 is rotated by 90 ° with respect to FIG. The magnetic flux from the N pole flows through the soft magnetic material 4 and the S pole. Therefore, the magnetic flux does not substantially flow through the attraction surfaces 40 and 41, and no attraction effect occurs. In FIG. 11, the other surfaces 42 and 43 of the soft magnetic material 4 form a closed magnetic path similarly to the above when the material 1 to be adsorbed is brought into close contact, and similarly exhibit an attracting action. By the way, the other surfaces 44 and 45 of the soft magnetic material cannot form a closed magnetic path and have substantially no adsorptivity.

[0003]

However, only two attracting surfaces can be used in such a rotating magnet configuration. Therefore, it has been difficult to perform operations such as in the case of a machine that requires multiple suction surfaces such as four or six surfaces. In addition, the attaching and detaching operation requires the rotation of the magnet, and the operation mechanism becomes complicated when incorporated in the automation of machinery and equipment. Accordingly, it is an object of the present invention to provide a magnet chuck that can be attracted on multiple sides and has a simple operation mechanism.

[0004]

According to the present invention, there is provided a rod-shaped permanent magnet having a plurality of magnetic poles having different magnetization directions at a constant pitch in an axial direction, and a soft magnetic material yoke. A chuck body having a magnetic material, which is magnetically cut off at predetermined intervals in an axial direction, into which a rod-shaped permanent magnet is inserted, and which has a through-hole which is closely surrounded around the rod-shaped permanent magnet; A magnet chuck characterized in that the magnetic field strength of a magnetic circuit closed loop formed between the divided soft magnetic material yokes by an axial relative movement with respect to the main body is adjustable.

[0005]

According to the above construction, a rod-shaped permanent magnet having a plurality of magnetic poles having different magnetization directions at a constant pitch in the axial direction is magnetically cut off and divided at a constant interval in the axial direction by a non-magnetic material. When the magnetic flux flowing from the N pole of the bar-shaped permanent magnet to the adjacent S pole flows from the opposing soft magnetic yoke to the adjacent soft magnetic yoke and reaches the adjacent S pole due to the relative position with respect to the soft magnetic material yoke. When the magnetic attracting force acts on the material to be adsorbed located on the outer surface of the yoke, but the magnetic flux from the N pole flows to the adjacent S pole via the same soft magnetic material yoke, the magnetic attracting force is not exerted on the outer surface of the yoke. Will be. Therefore,
The magnetic attraction on the outer surface of the yoke can be adjusted by the relative movement between the bar-shaped permanent magnet and the soft magnetic material yoke. Further, since the soft magnetic material yoke surrounds the bar-shaped permanent magnet, it can be formed as an attraction surface all around the yoke main body in the axial direction, and the number of attraction surfaces is not limited. Further, since the operation of attaching and detaching the material to be adsorbed by the magnetic attraction force is a relative operation in the axial direction,
It can be operated by a simple external input, for example, an air cylinder or an electric input, and can be easily incorporated into an automatic machine.

Further, when the division pitch of the soft magnetic material yoke divided in the axial direction by the non-magnetic material corresponds to or substantially corresponds to the magnetic pole pitch of the rod-shaped permanent magnet, the axial direction of the rod-shaped permanent magnet and the chuck body is changed. Due to the relative movement, different magnetic poles can be distributed and located in the adjacent soft magnetic material yoke area. As a result, the magnetic flux flowing from the N pole to the adjacent S pole can effectively flow to the adjacent yoke, On the other hand, when a different magnetic pole is located in the same soft magnetic material yoke area, a closed loop of a magnetic circuit is formed in the soft magnetic material yoke, and a strong magnetic attraction force is generated on the outer surface of the yoke (see FIG. 3). The magnetic attraction force can be made substantially zero (see FIG. 4).

According to the magnet chuck of the present invention, the magnetic attraction force can be generated on the entire surface, but the magnetic attraction force on each surface can be controlled independently. That is, the chuck main body is formed into an external polygonal prism or a cylindrical body, for example, a quadrangular prism, and is magnetically cut off and divided at a plane including a diagonal line of the chuck main body. It is preferable that a plurality of magnet chucks be integrated by inserting a rod-shaped permanent magnet having a plurality of magnetic poles having different magnetization directions at a constant pitch in the axial direction through each one (FIG. 1).
0 (a)). When two or more rod-shaped permanent magnets are inserted into each divided column to increase the magnetic flux density on the outer surface of the yoke, for example, as shown in FIG. It is necessary to consider the insertion position of each bar-shaped magnet so that the magnet flows easily and the magnetic flux density inside the yoke is made uniform. FIG. 10 (c)
In the case where the chuck body is an octagonal prism as shown in FIG. 10 and in the case where the chuck body is a cylinder as shown in FIG. 10 (d), the chuck body is divided into eight or four in the longitudinal direction at the surface 33 toward the center. The rod-shaped permanent magnet 2 is inserted into the hole 4 through the through hole 10. Here, a mounting hole 11 is formed in the center of the chuck body, and is mounted at a predetermined position via a rotating shaft (not shown) made of a non-magnetic material. Also, a through hole extending in the axial direction is formed at the center of the outer polygonal column, the rod-shaped permanent magnet is inserted, and a magnetic shielding plate extending in the axial direction from the through hole to the outer periphery of the chuck body is formed at a predetermined angle around the through hole. If a plurality of pieces are arranged and divided, the magnetic attraction force corresponding to the division angle can be generated and erased on each of the divided chuck body surfaces (see FIG. 9).

On the other hand, according to the present invention, a bar-shaped permanent magnet having a plurality of magnetic poles having different magnetization directions at a constant pitch in the axial direction, and a soft magnetic material yoke which is surrounded in close proximity to the bar-shaped permanent magnet And a chuck body composed of a non-magnetic material and a chuck body which is magnetically cut off and divided at predetermined intervals in the axial direction, and connected in parallel to form a wide magnetic attraction surface (see FIG. 5). As shown in FIG. 10 (e), the composite chuck bodies connected in parallel can be arranged so as to form each side surface of a quadrangular prism, thereby forming a composite chuck body having a wide magnetic attraction surface. In one of these composite chuck bodies, if one movable magnet is fixed, it is possible to increase the magnitude of the magnetic attraction force by strengthening and canceling the superposition and cancellation of the magnetic flux of the fixed rod magnet and the movable rod magnet (see FIG. 6). That is, an even number of rod-shaped permanent magnets are formed by forming a plurality of magnetic poles having different magnetization directions at a constant pitch in the magnetic flux canceling axial direction, and the rod-shaped permanent magnets are inserted therein, and the through holes extending in the axial direction surround in close proximity thereto. And a half of the chuck body, which is made by magnetically interrupting and dividing the soft magnetic material yoke at predetermined intervals in the axial direction with a non-magnetic material, faces the soft magnetic material yoke through the through hole. It is fixed to the integrated structure, the other half is slidably inserted as a movable magnet, and this movable magnet is moved in the axial direction with a magnetic pole pitch, and the same pole of each bar-shaped permanent magnet is connected by a soft magnetic material yoke to generate an attractive force. Further, it is preferable that the movable magnet be moved in the direction of the magnetic pole in the direction opposite to the movable direction to form a closed loop of the magnetic circuit via the soft magnetic material yoke so that the attraction force becomes substantially zero.

The relative movement of the rod-shaped magnet can be operated by an air cylinder or an electric input. An electromagnetic plunger having at least a part of the rod-shaped magnet as a movable element of the electromagnetic plunger is connected to the magnet chuck to form an integral body. With this structure, the rod-shaped permanent magnet can be movably operated in the axial direction by an electric operation input (see FIG. 7). At this time, if a stopper is provided on at least one end of the magnetic chuck and the stopper is formed of a soft magnetic material or a permanent magnet (see FIG. 8), the operation state can be stored, so that it can be easily incorporated into an automatic machine tool. Becomes

[0010]

FIG. 1 is a partial cutaway view of the present invention. 2 is a bar-shaped permanent magnet provided with a plurality of magnetic poles in the axial direction, and 7 is a bar for operating the magnet 2, which is integrated with the magnet. Reference numeral 4 denotes a square soft magnetic yoke provided at magnetic pole pitch intervals, and reference numeral 3 denotes a nonmagnetic material provided between the soft magnetic yokes 4. The soft magnetic yoke 4 and the nonmagnetic material 3 have an integral structure. (Through hole) 10 is provided. At both ends of the integrated structure, stoppers 5 and 6 for determining the movable range of the magnet 2 are provided.

FIG. 2 shows a rod-shaped permanent magnet 2, which is mainly composed of Mn-Al-C.
Since it has such a property that the easy magnetization axes are aligned in the extrusion direction, a rod-shaped permanent magnet integrally formed with a plurality of magnetic poles having different magnetization directions at a constant pitch in the axial direction can be obtained. Its axial characteristic is a residual magnetic flux density of 0.55T (55
00 Gauss), coercive force 200 KA / m (2500 Oersted), and radial characteristics are residual magnetic flux density 0.27T.
(2700 gauss), coercive force 144 KA / m (1800
Oersted). A rod-shaped permanent magnet can be formed by joining ordinary ferrite magnets. At that time, it is necessary to provide a structure in which a non-magnetic material or a soft magnetic material is interposed at the joint between the magnets so that the magnetic flux in the axial direction flows out to the outer peripheral surface.

FIG. 2A shows a change in surface magnetic flux density when the bar-shaped magnet 2 is a column and the magnetic poles are magnetized in a ring shape, and FIG. 2B shows the inside and outside of the magnet 2 at that time. Shows the state of the magnetic flux flowing through. Here, the interval at which the maximum amplitude of the surface magnetic flux occurs is called a magnetic pole pitch. Thus, the rod-shaped M
In order to complete the magnetized state shown in FIG. 2 using the n-Al-C material, as shown in FIG. Magnetizer 5 composed of coils 52, 52 wound with a magnetic pole pitch
Magnetization is performed at 0. In the magnetizer 50, since the direction of the magnetizing current is set so that the magnetization direction is reversed at the magnetic pole pitch interval, the lines of magnetic force flow from the inside of the magnet to the outer peripheral surface of the magnet as shown by the lines of magnetic force 53 shown in the figure. Therefore, the characteristics of the magnet material in the axial direction and the radial direction can be sufficiently utilized, and the magnetic flux can be converged on the outer peripheral surface.

Next, FIG. 3, which is a cut section of FIG.
The structure and operation of the magnet chuck will be described in detail with reference to FIG. FIG. 3 shows the attracted state, in which the adsorbed material 1 is in close contact with the outer surface of the magnet chuck. The magnetic flux emitted from the N-pole forms a closed magnetic path flowing from the soft magnetic material yoke 4 which is close to and opposed to the adsorbent 1 which is in close contact with the outside, and then from the adjacent soft magnetic yoke 4 which is close to and opposed to the S-pole. create. Therefore, the material to be adsorbed 1 is adsorbed by the soft magnetic material yoke 4. Reference numeral 9 denotes a magnetic pole pitch (see FIG. 2A), and reference numeral 8 denotes an air gap which is half the magnetic pitch. In this state, the magnet 2 is in contact with one of the stoppers 6. FIG. 4 shows a non-adsorbed state, in which the magnet 2 is in contact with one of the stoppers 5 and is movable by half the magnetic pole pitch. The magnetic flux from the N pole flows from the same soft magnetic material yoke 4 to the S pole. Therefore, the outer surface of the soft magnetic material yoke 4 has a substantially zero attractive force. In the embodiment, four suction surfaces are used, but the outer surface may be a polyhedron or a column.

FIG. 5 shows an embodiment in which two bar-shaped permanent magnets are provided. Although not shown, two bar-shaped permanent magnets 2 provided with an operating rod 7 are provided. As a result, the magnetic flux to the outer surface increases, and the attraction force also increases. Note that a plurality of holes may be provided to provide a plurality of bar-shaped permanent magnets 2.

FIG. 6 shows an embodiment in which two bar-shaped permanent magnets are provided and the attaching / detaching operation is performed by one bar-shaped magnet. The bar-shaped permanent magnet 2 a is fixed to stoppers 5 and 6. One rod-shaped permanent magnet 2b has an operation rod 7 attached thereto. FIG.
1 shows an attracted state, and the material 1 to be adsorbed is not shown, but the same poles of two rod-shaped magnets 2a and 2b are magnetically connected by a soft magnetic yoke 4. There is a gap 9 between the end of the magnet 2b and the stopper 5 which is equal to the magnetic pole pitch. Although the non-adsorbed state is not shown, when the gap 9 is zero, that is, when the magnet 2b is in contact with the stopper 5, the magnets 2a and 2b form a closed magnetic path via the soft magnetic material yoke 4, and The suction force on the side surface becomes zero. Note that a plurality of magnets 2a and 2b may be provided in pairs.

FIG. 7 shows an embodiment in which an external operation is performed by an electric input. Also, a closed structure is possible as shown by the configuration. Reference numeral 20 denotes an electromagnetic plunger integrated with the non-magnetic material 3. Reference numeral 21 denotes a drive coil, and reference numeral 22 denotes an electric input lead wire. 23 integrated with the stopper 5 is made of a soft magnet or a permanent magnet, and has a function of storing a state.

FIGS. 8A and 8B illustrate the operation of the electromagnetic plunger. FIG. 8A shows a state in which the electromagnetic plunger is attracted, and the electromagnetic plunger 20 and each pole of the magnet 2 are in the attracted state. In this state, even if the excitation input is set to zero, the magnet 2 is attracted to the iron core of the electromagnetic plunger 20 and maintains the state.
(B) The figure shows the repulsion state of the electromagnetic plunger.
Each pole of the electromagnetic plunger 20 and the magnet 2 repels, and the magnet 2
Will be in contact with 23. In this state, even if the excitation input is set to zero, the magnet 2 and the stopper 23 are attracted and the state is maintained.

FIG. 9 is a sectional view of the front surface of the yoke for adjusting the attraction force of the outer surface of the soft magnetic material yoke.
The soft magnetic material yoke 4 is divided by the non-magnetic material 33 and has an integral structure. The magnetic flux from the bar-shaped permanent magnet 2 is supplied to the outer surface of each soft magnetic material yoke at the illustrated angle, and the attraction force is adjusted independently for each surface according to the amount. In addition,
Adjustment by division other than implementation is also possible.

FIG. 10 is a front sectional view showing an embodiment in which the attaching / detaching operation of the outer surface of the soft magnetic material yoke 4 is performed independently for each surface. Numeral 33 indicates that each outer surface and the soft magnetic material yoke 4 are magnetically divided and have an integral structure. Accordingly, the bar-shaped permanent magnets 2a, 2b, 2c, and 2d are not magnetically coupled, and independent attachment / detachment operations of each attraction surface are possible.

As described above, according to the present invention, a plurality of magnetic poles N and S having different magnetization directions are provided alternately in the axial direction.
Preferably, a plurality of bar-shaped permanent magnets, in which all or most of the constituent magnetic poles have the same magnetic pole pitch, and a soft magnetic material yoke which is close to and surrounds the permanent magnet and is slightly shorter than the magnetic pole pitch in the axial direction, at a magnetic pole pitch interval. A non-magnetic material is provided between the soft magnetic material yokes to form an integral structure, and the permanent magnet is moved half a pitch of the magnetic pole pitch in the axial direction with respect to the chuck body, and the soft magnetic material yoke is opposed to the magnetic pole. An attractive force is generated on the surface of the magnetic material yoke that is not opposed to the permanent magnet, and the magnetic pole is short-circuited magnetically by the soft magnetic material yoke by moving the magnetic pole half pitch in a direction opposite to the above-mentioned movable direction. , Because the adsorption power was set to substantially zero,
The entire outer periphery of the magnet chuck can be a suction surface, and the number of suction surfaces is not limited. In addition, the attachment / detachment operation can be performed in the axial direction, and can be operated by a simple external input, for example, an air cylinder or an electric input, and can be easily incorporated into an automatic machine.

[Brief description of the drawings]

FIG. 1 is a partial sectional perspective view of a magnet chuck according to an embodiment of the present invention;

FIG. 2 is a graph (a) and a schematic diagram (b) showing a magnetized state of the bar-shaped permanent magnet shown in FIG. 1, a sectional view showing a magnetizing step,

FIG. 3 is an operation explanatory view of the magnet chuck shown in FIG. 1, showing a suction state.

FIG. 4 is an operation explanatory view similar to FIG. 3, showing a non-sucking state.

FIG. 5 is a perspective view of a composite magnet chuck according to another embodiment of the present invention;

FIG. 6 is a sectional view of another embodiment of the composite magnet chuck of the present invention;

FIG. 7 is a partial cross-sectional perspective view of another embodiment for explaining the driving operation of the magnet chuck of the present invention.

FIG. 8 is a sectional view for explaining the operation of the magnet chuck of FIG. 7;

FIG. 9 is an end view of a magnet chuck capable of performing surface suction force control according to the present invention;

FIG. 10 is a diagram illustrating the suction force control of each side independently according to the present invention .
In the end view of another composite magnet chuck that can
The case where the lock body is a quadrangular prism is shown.

FIG. 11 is a diagram illustrating the suction force control of each side independently according to the present invention .
In the end view of another composite magnet chuck that can
The main body is a quadrangular prism, and multiple rod-shaped permanent magnets are inserted into each divided column.
Indicates the case where it is entered.

FIG. 12 is a diagram illustrating the independent control of the suction force of each side according to the present invention .
In the end view of another composite magnet chuck that can
The case where the lock body is an octagonal prism is shown.

FIG. 13 is a diagram illustrating the independent control of the suction force on each side according to the present invention.
In the end view of another composite magnet chuck that can
The case where the lock body is a cylinder is shown.

FIG. 14 is a control of the suction force of each side independently according to the present invention.
Other that can In the end view of the composite magnet chuck of
This shows a case where each surface of the lock body is formed of a composite.

FIG. 15 is an end view for explaining the operation of the conventional rotary operation type magnet chuck, and shows a suction state.

FIG. 16 is an end view for explaining the operation of the same magnet chuck as that of FIG . 15 and shows a non-sucking state;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Adsorbed material 2 Permanent magnet 3 Non-magnetic material 4 Soft magnetic yoke 5, 6 Stopper 7 Operation rod 10 Through hole 20 Electromagnetic plunger

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor: Sachi Nakanishi 1006 Kazuma Kadoma, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. Address Sanyo Special Steel Co., Ltd.

Claims (8)

(57) [Claims] 1. A bar-shaped permanent magnet formed by forming a plurality of magnetic poles having different magnetization directions at a constant pitch in an axial direction, and a soft magnetic material yoke which is magnetically cut off and divided by a non-magnetic material at a constant interval in an axial direction. And a chuck main body having a through hole which is inserted in the vicinity of the rod-shaped permanent magnet and surrounds the perimeter of the rod-shaped permanent magnet, and which is divided by the axial relative movement of the rod-shaped permanent magnet and the chuck main body. A magnetic chuck, wherein the magnetic field strength of a magnetic circuit closed loop formed between magnetic material yokes is adjustable. 2. A pitch of the soft magnetic material yoke divided in the axial direction by the non-magnetic material corresponds to or substantially corresponds to a magnetic pole pitch of the rod-shaped permanent magnet, and an axial relative distance between the rod-shaped permanent magnet and the chuck body. Movement causes different magnetic poles to be distributed and located in adjacent soft magnetic material yoke areas, forming a closed magnetic circuit across adjacent yokes to generate a strong magnetic attraction force on the outer surface of the yoke, while using different magnetic poles of the same soft magnetic material. 2. The magnet chuck according to claim 1, wherein the magnet chuck is located in a yoke area, wherein a closed loop of a magnetic circuit is formed in the soft magnetic material yoke so that a magnetic attraction force on an outer surface of the yoke is substantially zero. 3. A through hole formed in the longitudinal direction of each of the chuck bodies in the form of a polygonal cylindrical body or a cylindrical body having a shape facing the center thereof, which is magnetically cut off and divided at a surface facing the center thereof. A plurality of magnet chucks are integrated by inserting one or more of the above-mentioned bar-shaped permanent magnets, and the magnetic attraction force of each divided outer surface of the chuck body is independently generated by sliding each of the bar-shaped permanent magnets. 3. The composite magnet chuck according to claim 1, wherein the composite magnet chuck is configured to perform the following. 4. The chuck body has a polygonal cylindrical body or a cylindrical body having an outer shape. The rod-shaped permanent magnet is inserted into the center of the chuck body, and the chuck body has an axially extending through hole close to and surrounding the permanent magnet. A plurality of magnetic shielding plates extending in the axial direction extending to the outer periphery of the chuck body are arranged at predetermined angles around the through holes, and the chuck body divided by sliding the rod-shaped permanent magnet to a magnetic attraction force corresponding to the division angle. 3. The composite magnet chuck according to claim 1, wherein generation and erasure control is performed on the surface. 5. A bar-shaped permanent magnet formed by forming a plurality of magnetic poles having different magnetization directions at a constant pitch in the axial direction, and a soft magnetic material yoke surrounding and surrounding the bar-shaped permanent magnet by a non-magnetic material. 3. The composite magnet chuck according to claim 1, wherein magnet chucks each comprising a chuck body magnetically interrupted and divided at predetermined intervals in an axial direction are connected in parallel to form a wide magnetic attraction surface. 6. An even number of rod-shaped permanent magnets each having a plurality of magnetic poles having different magnetization directions at a constant pitch in an axial direction,
The bar-shaped permanent magnet is inserted, has a plurality of axially extending through holes surrounding the permanent magnet in close proximity thereto, and the soft magnetic material yoke is magnetically cut off at regular intervals in the axial direction using a non-magnetic material. One half of the chuck body is opposed to the soft magnetic material yoke through the through hole and fixed to the integral structure, and the other half is slidably inserted as a movable magnet. The same poles of the bar-shaped permanent magnets are connected by a soft magnetic material yoke to generate an attraction force, and the movable magnet is moved at a magnetic pole pitch in a direction opposite to the above movable direction to form a closed loop of a magnetic circuit through the soft magnetic material yoke. A magnet chuck configured to make the suction force substantially zero. 7. An electromagnetic plunger, wherein at least a part of the rod-shaped magnet is configured as a movable element of the electromagnetic plunger,
The magnet chuck according to any one of claims 1 to 6, wherein the rod-shaped permanent magnet is movable in the axial direction by an electric operation input. 8. The magnet chuck according to claim 1, wherein a soft magnetic material or a permanent magnet is provided at at least one end of the magnet chuck to serve as a stopper so that an operation state can be stored.