TWI685395B - Magnet chuck - Google Patents

Abstract

A magnet chuck (10) includes, for example, four permanent magnets of a first permanent magnet (56a) through a fourth permanent magnet (56d), serving as an attracting and retaining member for attracting and retaining a workpiece (12). In the first permanent magnet (56a) and the third permanent magnet (56c), the magnetic polarity of a workpiece magnetic attracting surface facing the workpiece (12) is of an N-polarity. on the other hand, in the second permanent magnet (56b) and the fourth permanent magnet (56d), the magnetic polarity of a workpiece magnetic attracting surface is of an S-polarity. More specifically, in this case, combinations of the N-pole and the S-pole on the workpiece magnet attracting surface are formed in two pairs, and the N-pole and the S-pole, which are of different polarities, are adjacent to one another.

Description

Magnetic chuck

The invention relates to a magnetic chuck for attracting and holding a workpiece with the magnetic force of a permanent magnet.

The magnetic chuck contains an electromagnet or one of permanent magnets. In the case of an electromagnet, the magnetic force is generated by starting to supply current to the electromagnet (ie, energized), and the workpiece is attracted and held by the magnetic force. In addition, when the current supply is stopped, the magnetic force disappears, and as a result, the workpiece is released.

On the other hand, in the case of permanent magnets, for example, as disclosed in Japanese Early Patent Publication 55-078505, there is a configuration for attracting and holding and switching to release the workpiece by rotating the permanent magnet. However, more generally, a configuration is known in which a permanent magnet is connected to a piston, and the permanent magnet is displaced together with the piston (for example, refer to Japanese Early New Publication 51-102174). The magnetic chuck disclosed in the Japanese early new publication 51-102174, after displacement with the piston that has received the pressure fluid, causes the permanent magnet to be close to the workpiece, and then uses it to attract and hold the workpiece. In addition, when the permanent magnet and piston are displaced in the direction away from the workpiece, the workpiece is released.

Such a magnetic chuck, for example, is installed on the remote arm of the robot, and along with the robot performing a predetermined operation, the workpiece attracted and held will be transported to a predetermined position.

When attracting a workpiece with a large weight, it is considered that, as far as the permanent magnet is concerned, the one with a large magnetic force should be selected. In this case, it is expected to generate a large suction force. However, in particular, in the case where the workpiece is a thin plate, since magnetic saturation occurs in the interior of the workpiece, it is not easy to generate a large suction force.

The main object of the present invention is to provide a magnetic chuck that can express a large suction force to a workpiece.

According to a specific embodiment of the present invention, a magnetic chuck for attracting and holding a workpiece by a magnetic attraction surface of the workpiece facing the workpiece by the magnetic force of a plurality of permanent magnets is provided. The magnetic chuck includes a cylinder tube (cylinder tube) ) Within a piston. The plurality of permanent magnets are configured to be displaced in the same direction as the displacement direction of the piston when the piston is displaced due to a pressing force from a pressure fluid, and the plurality of permanent magnets are configured to As a result, there is one or more pairs of N-pole and S-pole combinations on the magnetic attraction surface of the workpiece.

The permanent magnet may be a separate magnet. More specifically, according to another embodiment of the present invention, there is provided a magnetic chuck that attracts and holds a workpiece by the magnetic force of the workpiece facing the workpiece by the magnetic force of a permanent magnet. The magnetic chuck includes a housing A piston in the cylinder tube. The permanent magnet is configured to be in the same direction as the displacement direction of the piston when the piston receives a pressing force from a pressurized fluid and thereby displaces Shift, and the permanent magnet is assembled to be magnetized to cause one or more pairs of N and S poles to exist on the magnetic attraction surface of the workpiece.

In each of the above configurations, the magnetic flux generated by the exposed N pole on the magnetic attraction surface of the workpiece points to the exposed S pole on the magnetic attraction surface of the same workpiece. Therefore, compared to the case where the magnetic polarity of the magnetic attraction surface of the workpiece is one of N pole or S pole, that is, compared to the prior art magnetic chuck having one pole, the magnetic circuit in the workpiece can be made (The number of magnetic currents) is large. More specifically, regarding the magnetic saturation point appearing inside the workpiece, although the same as the prior art, compared with the prior art, the present invention can greatly increase the magnetic flux through the workpiece. As a result, a large suction force will be revealed for the workpiece. This feature is particularly noticeable when different magnetic poles (N pole and S pole) are arranged adjacently.

From the fact that the suction force is made larger in the above manner, even in the case where the workpiece is a thin-walled member (for example, a thin steel plate) and magnetic saturation is likely to occur inside it, it can still effectively attract and fully hold the workpiece with magnetic force . In other words, the present invention is particularly effective when the thickness of the workpiece is small.

As can be understood from the above, assuming that the materials and characteristics of the permanent magnets are the same as those of the prior art magnetic chucks, when their sizes are the same, the present invention can increase the suction force to the workpiece. On the other hand, since the suction force is the same as that of the prior art permanent magnet, a permanent magnet with a smaller size can be made, and the magnetic chuck can be scaled down (miniaturized).

In the case of using a plurality of individual permanent magnets, the permanent magnet may be a permanent magnet whose magnetization direction is perpendicular to the magnetic attraction surface of the workpiece. In this case, the magnetic polarities of the permanent magnets on the magnetic attraction surface of the workpiece (the surface facing the workpiece) and the back surface are different. As a result, multiple individual permanent magnets are used Iron can form one or more pairs of N pole and S pole on the magnetic attraction surface of the workpiece.

In addition, with this configuration, the magnetic current generated by the exposed N pole on the magnetic attraction surface of the workpiece is directed to the exposed S pole on the magnetic attraction surface of the workpiece and the exposed S pole on the back surface of the magnetic attraction surface of the workpiece. More specifically, the magnetic circuit (the number of magnetic currents) can be further increased. The suction force coupled with it can be further enhanced.

In the above configuration, it is sufficient if the N pole and the S pole reside on the magnetic attraction surface of the workpiece to become one pole (in other words, the combination of the N pole and the S pole is a pair). However, when the N pole and the S pole each reside as two poles (in other words, the combination of the N pole and the S pole is two pairs), the suction force becomes larger, which is preferable.

The permanent magnet of the above configuration can be supported on the piston through the yoke. In this case, the presence of the yoke makes the suction more powerful. As a result, the workpiece can be attracted and held more effectively.

As for the permanent magnets, at least three individual permanent magnets arranged in a Halbach array can be used. More specifically, the Halbach array is formed by: two permanent magnets whose magnetization direction is perpendicular to the magnetic attraction surface of the workpiece, and at least one permanent magnet disposed between the two permanent magnets and whose magnetization direction is parallel to the magnetic attraction surface of the workpiece magnet. In addition, the N pole of one of the two permanent magnets whose magnetization direction is perpendicular to the magnetic attraction surface of the workpiece, and the S pole of the other of the two permanent magnets can be exposed on the magnetic attraction surface of the workpiece.

Each of the plurality of permanent magnets may be a U-shaped magnet. In this U-shaped magnet, one of the two distal ends is the N pole, and the other of the two distal ends is the S pole. As a result, by making each U-shaped magnet The two poles face the workpiece, and two or more pairs of N and S poles can be exposed on the magnetic surface of the workpiece.

On the other hand, in the case where the number of the permanent magnets is a single individual magnet, for example, a magnetized U-shaped magnet can be used as the permanent magnet. In this case, both the N pole and the S pole are exposed on the magnetic attraction surface of the workpiece. This permanent magnet can be manufactured by bringing a U-shaped magnet close to one end face and magnetizing it.

Alternatively, the magnetization direction of the permanent magnet may be perpendicular to the magnetic attraction surface of the workpiece. More specifically, both the N pole and the S pole are exposed on the magnetic attraction surface of the workpiece, and both the N pole and the S pole are also exposed on the back surface thereof. This permanent magnet can be manufactured by bringing a U-shaped magnet close to one end face, another U-shaped magnet close to its back face, and magnetizing it.

In the above configuration, when the permanent magnet rotates, the magnetic current density in the vicinity of the automatic switch changes, and as a result, it is considered that it may cause an erroneous operation of the automatic switch. Therefore, in the cylinder tube, it is preferable to provide a rotation prevention member to prevent the permanent magnet from rotating. Due to this feature, the fear of causing the above situation can be eliminated.

When the anti-rotation member is provided, the anti-rotation member is preferably made of a ferromagnetic metal, and is disposed on the boundary between the N pole and the S pole adjacent to the magnetic attraction surface of the workpiece. With this configuration, it becomes the most difficult for the permanent magnet rotator, instead of setting the anti-rotation member at another position.

The anti-rotation member is preferably a connecting member for connecting the cylinder tube and a head cover. In this case, since the connecting member used to assemble the magnetic chuck is used as the anti-rotation member, it is not necessary to use External independent anti-rotation member. Therefore, by avoiding an increase in the number of parts, it is possible to make a magnetic chuck with a more compact size. This configuration is also cost-effective.

In addition, it is preferable to provide a sealing member on a side wall of the piston, and a portion between the piston and the cylinder tube can be sealed with the sealing member. In this case, at any time when the permanent magnet advances or retracts, the piston receives a pressing force from the pressure fluid. The pressure receiving area of the piston when the permanent magnet advances is approximately equal to the pressure receiving area of the piston when the permanent magnet is retracted, and therefore, the thrust during advancement and retraction is substantially equivalent. As a result, for example, the reaction speed when the workpiece is attracted by magnetic force and when the workpiece is released can be made substantially equivalent.

A magnet cover that is attached to the cylinder tube and covers the permanent magnet, and a buffer member that buffers when the permanent magnet attracts the workpiece can be detachably mounted on the magnet cover. In this configuration, when the permanent magnet attracts the workpiece, the buffer member is brought into contact with and intervened in the workpiece. As a result, the stress acting on the magnetic chuck can be reduced. More specifically, the buffer member performs a buffer function. Therefore, the vibration of the magnetic chuck can be suppressed.

At the same time, the buffer member acts as a non-slip device. More specifically, friction resistance occurs between the buffer member and the magnetically attracted work. Therefore, since it is difficult for the workpiece to experience sliding against the buffer member, it is possible to effectively prevent the workpiece from separating or falling off from the magnetic chuck.

In this configuration, it is preferable to install a plurality of buffer members, and the thickness of the buffer members protruding from the magnet cover is different from each other. In this case, the suction force to the workpiece can be changed by replacing the buffer member. Buffer structure The area where the piece is protruded by the magnet cover intervenes in the workpiece. Therefore, as the thickness of the buffer member protruding from the magnet cover becomes larger, the distance between the permanent magnet and the workpiece also increases. As a result, the influence of the magnetic force acting on the workpiece by the permanent magnet becomes more difficult.

The above and other objects, features, and advantages of the present invention can be more clearly understood from the following description in conjunction with the accompanying drawings, in which preferred specific embodiments of the present invention are shown with explanatory examples.

10‧‧‧Magnetic chuck

12‧‧‧Workpiece

14‧‧‧Cylinder tube

16‧‧‧Magnet cover

18‧‧‧hood

20‧‧‧Housing

22‧‧‧ First glide hole

23‧‧‧Lower chamber

24‧‧‧First middle chamber

25‧‧‧Hollow cylindrical column

26, 112, 118, 120 ‧‧‧ First annular groove

28, 28A to 28C, 110, 114, 116, 122

29a, 29c, 66‧‧‧ flange

29b, 29bA to 29bC

37‧‧‧ First port

38‧‧‧Second sliding hole

40‧‧‧Thin-walled part

42‧‧‧Plate

50‧‧‧Second port

54a to 54d

54a‧‧‧First tie bar

54b‧‧‧second tie bar

54c‧‧‧third tie rod

54d‧‧‧4th tie bar

56a‧‧‧First permanent magnet

56b‧‧‧Second Permanent Magnet

56c‧‧‧third permanent magnet

56d‧‧‧The fourth permanent magnet

58‧‧‧piston

60‧‧‧Second middle chamber

62‧‧‧ Upper chamber

64‧‧‧Yoke

68‧‧‧shaft

74‧‧‧Connecting bolt

78‧‧‧Insert hole

84‧‧‧ First shock absorber

85‧‧‧Connecting groove

90‧‧‧The third sealing member

94‧‧‧Second shock absorber

Figure 1 is a schematic perspective view of main components of a magnetic chuck according to an embodiment of the present invention; Figure 2 is a plan view seen from the direction of arrow A in Figure 1; Figure 3 is along the edge of Figure 2 The cross-sectional view drawn along line III-III; the general vertical cross-sectional view of FIG. 4 shows the situation when the piston, yoke, and first to fourth permanent magnets are displaced downward from the state shown in FIG. 3; Figures 5A and 5B are respectively a schematic side view of the magnetic flux when the number of poles on the magnetic attraction surface of the workpiece is one and a schematic plan view showing the magnetic saturation region; Figures 6A and 6B are respectively magnetic attraction on the workpiece The schematic side view of the magnetic current when the number of poles on the surface is two (the N pole and the S pole are combined into a pair) and the schematic plan view showing the magnetic saturation region; Figure 7 is the number of poles shown on the magnetic attraction surface of the workpiece Is a schematic side view of the magnetic saturation region when four (N pole and S pole are combined into two pairs); the graph in Figure 8 shows the number of magnetic poles (the number of N pole and S pole combined) on the magnetic attraction surface of the workpiece Relationship with generating suction; FIGS. 9A to 9C are cross-sectional views of the main components, which illustrate the case where different numbers of buffer members protruding from the magnet cover are attached; the graph of FIG. 10 is shown in the attached diagram at 9A Change of suction force to the workpiece when the cushioning member from FIG. 9C to FIG. 9; the general perspective view of FIG. 11 illustrates the case where the magnetic attraction surface of the workpiece is formed by the assembly of three U-shaped permanent magnets; the general bottom view of FIG. 12 Shows the case where the magnetic attraction surface of the workpiece is formed by the assembly of two U-shaped permanent magnets; the summary front view of Figure 13 shows the formation of the Haierbeck array with several rod-shaped magnets, and a Group N pole and S pole combination; the general overall perspective view of Figure 14 shows a permanent magnet obtained by magnetizing a cylinder so that the direction of the magnetic pole in it is U-shaped; the general overall perspective view of Figure 15 is shown by The permanent magnet obtained from the magnetized cylinder is such that the direction of the magnetic pole in it is perpendicular to the magnetic attraction surface of the workpiece; the general cross-sectional view of the main components in Figure 16 shows the attachment of a buffer member with a different shape; the general cross-section of the main components in Figure 17 The figure shows the attachment of another buffer member with a different shape; the general sectional view of the main components of FIG. 18 shows the attachment of yet another buffer member with a different shape; and the general sectional view of the main components of FIG. 19 shows the attachment of a more Buffer members with different shapes.

The following is a detailed description of preferred embodiments of the magnetic chuck of the present invention with reference to the drawings. In the following description, the terms "upward" and "downward" correspond to the upward and downward directions of Figures 1, 3, and 4. In addition, in this specific embodiment, a case where compressed air is used as a working fluid is exemplified.

FIGS. 1 to 3 are respectively a schematic perspective view illustrating the main components of the magnetic chuck 10 according to an embodiment of the present invention, a plan view seen from the direction of arrow A in FIG. 1, and along the second The cross-sectional view drawn by line III-III in the figure. The magnetic chuck 10 attracts and holds the workpiece 12 shown in FIG. 3. Of course, the work piece 12 is composed of a ferromagnetic material, and a thin steel plate can be exemplified as its detailed embodiment. The thickness T1 of the workpiece 12 is about 0.5 to 2 mm, and usually about 0.6 mm.

The magnetic chuck 10 includes a housing 20 configured by attaching the magnet cover 16 and the head cover 18 to the cylinder tube 14. Hereinafter, referring mainly to FIG. 3, initially, the magnet cover 16 is made of a hollow body in which the first glide hole 22 is formed to extend in the longitudinal direction of each other. In the first glide hole 22, the lower chamber 23 and the first intermediate chamber 24 are defined by a flange 66 (holding member) and a plate 42 (partition member) of the yoke 64 described later. More specifically, the lower chamber 23 is a space between the bottom wall of the magnet cover 16 and the lower end surface of the flange 66. In addition, the first intermediate chamber 24 is a space between the upper end surface of the flange 66 and the lower end surface of the plate 42.

A hollow cylindrical column 25 protruding from the lower end surface of the magnet cover 16 is formed, and a first annular groove 26 surrounding the first glide hole 22 (lower chamber 23) is formed in the hollow cylindrical column 25. In the first annular groove 26, construct one The buffer member 28, and the flange 29a into which it is inserted, have a slightly larger diameter and protrude radially outward. After the flange 29a has been received in the first annular groove 26, it returns to its original shape by its elasticity, preventing the flange 29a from falling out of the first annular groove 26. As a result, the cushion member 28 is prevented from falling off from the magnet cover 16.

By elastically deforming the buffer member 28, the flange 29a can be easily inserted into and separated from the first annular groove 26. In other words, the buffer member 28 is detachably attached to the magnet cover 16.

The cylindrical portion 29b of the buffer member 28 having a smaller diameter than the flange 29a covers the hollow cylindrical column 25. In addition, one end of the cylindrical portion 29b is projected into a ring shape by the hollow cylindrical column 25 (magnet cover 16). In addition, a plurality of individual slits 29 are formed in the buffer member 28 (refer to FIG. 2).

The buffer member 28 constructed in the foregoing manner is preferably made of a suitable oil resistant material. As an example of this preferred material, fluororubber, silicone rubber, neoprene rubber, nitrile rubber, acrylic rubber, or the like can be cited. The material of the buffer member 28 may be resin.

Preferably, a plurality of buffer members 28 are prepared. In this case, as for the plurality of individual buffer members 28, the number D of the cylindrical portions 29b protruding from the hollow cylindrical column 25 may be selected to be different from each other. This will be discussed in more detail below.

The shape of the middle flank portion 30 (refer to FIG. 3) of the magnet cover 16 is substantially in the form of a rectangular parallelepiped, and the upper end portion 32 is formed into a substantially cylindrical shape. Based on these different shapes, the middle side wing portion 30 and the upper end portion 32 on the magnet cover 16 form a step Stepped part 34. The first sealing member 36 is disposed on a side wall of the upper end 32.

In addition, a first port 37 is formed in one side of the middle side wing portion 30. The first port 37 communicates with the lower chamber 23.

A second glide hole 38 extending in the longitudinal direction of the cylinder tube 14 is formed. The cross section of the second sliding hole 38 perpendicular to the longitudinal direction is a substantially perfect circle. In addition, the second glide hole 38 opens at the upper and lower ends of the cylinder tube 14. More specifically, the cylinder tube 14 is a hollow body whose outer shape is formed into a substantially rectangular parallelepiped.

The thin-walled portion 40 is formed near the opening of the lower end side of the second glide hole 38 by recessing its inner wall toward the outer wall side. In this way, the thickness of the thin-walled portion 40 that is smaller than the other areas is set. The lower end surface of the thin-walled portion 40 abuts the stepped portion 34 of the magnet cover 16. In addition, the upper end portion 32 of the magnet cover 16 is inserted through the second sliding hole 38 and fits into the thin-walled portion 40 together. The portion between the thin portion 40 and the upper end 32 of the magnet cover 16 is sealed by the first sealing member 36.

The outer edge of the plate 42 is sandwiched between the upper end surface of the magnet cover 16 and the ceiling surface of the thin-walled portion 40. In other words, the plate 42 is sandwiched between the magnet cover 16 and the cylinder tube 14. The details about the board 42 will be described below.

The opening on the upper end surface of the cylinder tube 14 is closed with a head cover 18. An entry member 44 shaped as a substantially tubular column is formed to protrude from the lower end surface of the head cover 18. By allowing the entry member 44 to enter the inside of the cylinder tube 14, the head cover 18 can be fitted into the cylinder tube 14. The second sealing member 46 is provided on a side wall of the entry member 44, whereby the second sealing member 46 It is sealed at a portion between the cylinder tube 14 and the head cover 18.

A second port 50 is formed in one side of the head cover 18. The second port 50 is located on the same side on which the first port 37 is formed. A supply and exhaust mechanism (not shown) is connected to the first port 37 and the second port 50.

Bottomed rod holes 52 extending from the head cover 18 through the cylinder tube 14 and near the lower end of the middle-side wing portion 30 of the magnet cover 16 are formed in each of the four corners of the housing 20. The threaded portions of the first to fourth tie rods 54a to 54d (connecting members) inserted through the rod holes 52 are screw-engaged with the threaded portions engraved near the bottom of the rod hole 52. In addition, its head stops in an annular stepped portion 55 provided in the hood 18. With the threaded engagement of the first to fourth tie rods 54a to 54d, the head cover 18, the cylinder tube 14, and the magnet cover 16 are fastened together and connected, thereby forming the housing 20.

In the above structure, the head cover 18, the cylinder tube 14, and the magnet cover 16, for example, are made of paramagnetic metal, such as aluminum alloy or the like. On the other hand, the first to fourth tie bars 54a to 54d are made of ferromagnetic metal, such as cast iron (for example, corresponding to the material of SS400 subject to Japanese industrial standards), and as described below, as anti-rotation members, That is, a so-called rotation stop prevents rotation of the first to fourth permanent magnets 56a to 56d used as suction and holding members.

In the interior of the housing 20, the first glide hole 22 and the second glide hole 38 are separated by a plate 42. In addition, the second glide hole 38 is divided into a second intermediate chamber 60 and an upper chamber 62 by the piston 58 and the head cover 18.

On the other hand, the upper chamber 62 is formed on the piston 58 and the head cover 18 between the entry members 44. The second port 50 communicates with the upper chamber 62.

The magnetic chuck 10 includes first to fourth permanent magnets 56a to 56d for attracting and holding the workpiece 12 (refer to FIG. 3). Each of the first to fourth permanent magnets 56a to 56d is held in the yoke 64 by its own magnetic force through a connecting member, such as a retaining bolt or the like.

As shown in FIG. 2, the first to fourth permanent magnets 56a to 56d are each substantially fan-shaped, and the center angle is substantially 90° when viewed in plan. Due to the circular configuration of this cylinder, a tubular cylindrical permanent magnet is roughly constructed. More specifically, the first permanent magnet 56a contacts the second permanent magnet 56b and the fourth permanent magnet 56d adjacent to the first permanent magnet 56a contacts and faces the third permanent magnet 56c.

For example, the radius values of the first to fourth permanent magnets 56a to 56d may be set to about 10 to 30 mm. A typical embodiment of the radius is about 15 mm, and in this case, the diameter of the permanent magnets is about 30 mm as a whole.

In addition, a typical embodiment of the height (distance from the lower end surface to the upper end surface) of the first to fourth permanent magnets 56a to 56d is about 10 mm.

For ease of understanding, the bottom wall portion of the magnet cover 16 is omitted in FIG. 2. However, actually, the first to fourth permanent magnets 56a to 56d are partially covered by the bottom wall of the magnet cover 16 (refer to FIG. 3).

When the first to fourth permanent magnets 56a to 56d are uniformly displaced together with the yoke 64 and the piston 58 toward the workpiece 12, the drawing is attracted to Figure 3 Workpiece 12. More specifically, in the first to fourth permanent magnets 56a to 56d, their surfaces facing the workpiece 12 are used as magnetic attraction surfaces (attracting and holding surfaces) of the workpiece.

The magnetic polarity of the magnetic attraction surface of the workpiece of both the first permanent magnet 56a and the third permanent magnet 56c is N polarity. In contrast, the magnetic polarity of the magnetic attraction surface of the workpiece of both the second permanent magnet 56b and the fourth permanent magnet 56d is S polarity. As a result, the polarities of the magnetic attraction surfaces of the workpieces form the N pole (first permanent magnet 56a), S pole (second permanent magnet 56b), N pole (third permanent magnet 56c), and S pole ( The fourth permanent magnet 56d). More specifically, in this case, two pairs of N-pole and S-pole combinations are formed on the magnetic attraction surface of the workpiece, and the N-pole and S-pole facing the magnetic pole exposed to them with different polarities may be adjacent to each other.

On the side of the holding surface held by the yoke 64, opposite to the above, along the clockwise direction, they are sequentially arranged side by side into S pole (first permanent magnet 56a), N pole (second permanent magnet 56b) , S pole (third permanent magnet 56c), and N pole (fourth permanent magnet 56d).

The first tie bar 54a is located on the outer periphery of the boundary between the first permanent magnet 56a and the second permanent magnet 56b, or in other words, on the N pole (first permanent magnet 56a) and S pole (second On the outer periphery of the boundary of the permanent magnet 56b). Similarly, the second tie bar 54b, the third tie bar 54c, and the fourth tie bar 54d are each located on the outer periphery of the boundary between the second permanent magnet 56b and the third permanent magnet 56c, and are located on the third permanent magnet 56c and the fourth permanent magnet The outer periphery of the boundary between the magnet 56d and the outer periphery of the boundary between the fourth permanent magnet 56d and the first permanent magnet 56a. Finally, The first to fourth tie rods 54a to 54d are disposed on the boundary between adjacent magnetic poles on the magnetic attraction surface of the workpiece.

Since the first to fourth tie bars 54a to 54d are made of ferromagnetic metal, the magnetic force from the first to fourth permanent magnets 56a to 56d is also exerted on the first to fourth tie bars 54a to 54d. More specifically, suction force is generated between the first to fourth permanent magnets 56a to 56d and the first to fourth tie bars 54a to 54d.

As described above, since mutual attraction occurs between the first to fourth permanent magnets 56a to 56d and the first to fourth tie bars 54a to 54, the first to fourth permanent magnets 56a to 56d can be prevented from rotating. Finally, the first to fourth permanent magnets 56a to 56d are used to prevent the piston 58 and the yoke 64 from rotating. In this way, the rotation torque of the first to fourth permanent magnets 56a to 56d can be substantially zero with the first to fourth tie bars 54a to 54d used to form the housing 20.

When the first to fourth tie bars 54a to 54d are placed as described above, the rotational torque generated in the first to fourth permanent magnets 56a to 56d is reduced to a minimum. In other words, rotation prevention can be performed more effectively.

As described above, the first to fourth permanent magnets 56a to 56d are held by the yoke 64 (refer to FIG. 3). More specifically, the yoke 64 includes a large-diameter flange 66 and a small-diameter shaft 68. Each of the first to fourth permanent magnets 56a to 56d is held on the flange 66 by its own magnetic force or by a connecting member (for example, a bolt or the like). The flange 66 and the shaft 68 are integrally formed in the yoke 64 (by the same member). Furthermore, since the yoke 64 is formed of ferromagnetic metal, such as cast iron (corresponding to the material of SS400), the first to fourth permanent magnets The irons 56a to 56d become likely to be magnetically attracted to the flange 66.

For example, the flange 66 is set to have a thickness of approximately 10 mm. The flange 66 serves as an auxiliary yoke. In addition, a wear ring 70 is provided on one side wall of the flange 66. By the action of the wear ring 70, the center of the flange 66 can be prevented from shifting or sliding relative to the center of the first glide hole 22, and by extending the yoke 64, the flange 66 can be guided along the first glide hole 22 internal.

On the other hand, an annular recess 72 recessed toward the lower end surface side is formed on the upper end surface of the flange 66. In addition, a bolt hole 76 for screwing the connecting bolt 74 therein is formed on the upper end of the shaft 68.

The plate member 42 is disposed between the piston 58 and the first to fourth permanent magnets 56a to 56d (the flange 66 of the yoke 64). For this purpose, an insertion hole 78 that substantially penetrates the center of the plate 42 is formed so as to allow the shaft 68 of the yoke 64 to pass therethrough. Of course, the inner diameter of the insertion hole 78 is smaller than the outer diameter of the piston 58.

In addition, on the lower end surface of the plate member 42, a disc-shaped protrusion 80 protruding toward the flange 66 is formed. When the piston 58, the yoke 64, and the first to fourth permanent magnets 56a to 56d are located at a top dead center point (refer to FIG. 3) that is a displacement end point, the disc-shaped protrusion 80 enters and forms An annular recess 72 in the flange 66 of the yoke 64.

A wide second annular groove 82 is formed in the upper end surface of the plate 42. The ring-shaped first shock absorber 84 is accommodated in the second ring-shaped groove 82. The lower end surface of the piston 58 abuts the first shock absorber 84 when it reaches the bottom dead center point which is another displacement end point (refer to FIG. 4).

In addition, a connection is formed on the plate 42 near the insertion hole 78 The through groove 85 is used to enable communication between the first intermediate chamber 24 and the second intermediate chamber 60. Through the communication groove 85, the compressed air in the first intermediate chamber 24 may move into the second intermediate chamber 60, or the compressed air in the second intermediate chamber 60 may move into the first intermediate chamber 24.

The upper end surface of the shaft 68 inserted through the insertion hole 78 of the plate member 42 is inserted into the insertion hole 86 formed in the lower end surface of the piston 58. A bolt stopping hole 88 is formed in the piston 58 from the upper end face side to the insertion hole 86, and a connecting bolt 74 stopped in the bolt stopping hole 88 is screwed into the bolt hole 76. Due to this feature, the piston 58 and the yoke 64 are connected to each other, and the first to fourth permanent magnets 56 a to 56 d are indirectly held on the piston 58 through the yoke 64.

A third sealing member 90 is provided on one side wall of the piston 58. A portion between the piston 58 and the cylinder tube 14 is sealed by the third sealing member 90. More specifically, the compressed air in the upper chamber 62 is prevented from leaking into the second intermediate chamber 60 from between the side wall of the piston 58 and the inner wall of the second glide hole 38 of the cylinder tube 14. Similarly, the air in the second intermediate chamber 60 can be prevented from leaking into the upper chamber 62.

A wide third annular groove 92 is formed on the upper end surface of the piston 58. The annular second shock absorber 94 is accommodated in the third annular groove 92. When the piston 58 reaches top dead center, the second shock absorber 94 abuts the lower end surface of the entry member 44 of the joint cover 18 (refer to FIG. 3 ).

The magnetic chuck 10 according to the present specific embodiment is basically constructed in the above-described manner. Next, actions related to the operation of the magnetic chuck 10 and its advantageous effects are described.

The magnetic chuck 10 is provided, for example, on the remote arm of the robot (not shown). In addition, the robot performs a predetermined operation, as shown in FIG. 3, so that the magnetic attraction surfaces of the first to fourth permanent magnets 56 a to 56 d face the workpiece 12. At this time, the piston 58, the yoke 64, and the first to fourth permanent magnets 56a to 56d are all at the top dead center, and therefore, at this time, the magnetic force of the first to fourth permanent magnets 56a to 56d is not applied于WORK12.

Next, pressurized air is supplied by the intake and exhaust mechanism through the second port 50 to the upper chamber 62. The pressurized air presses the piston 58 from the upper end surface side. At the same time, under the action of the intake and exhaust mechanism, pressurized air is discharged from the lower chamber 23 through the first port 37. The pressurized air in the second intermediate chamber 60 moves into the first intermediate chamber 24 through the communication groove 85, and in addition, the pressurized air in the first intermediate chamber 24 is guided by the side wall of the flange 66 and the first glide hole The inner walls of 22 pass between and move into the lower chamber 23. After that, the pressurized air is also discharged through the first port 37.

The piston 58 that has received the pressure from the compressed air in the upper chamber 62 will be displaced (dropped) in the direction of approaching the plate 42. Since the lower chamber 23, the first intermediate chamber 24, and the second intermediate chamber 60 are all under negative pressure, the piston 58 is easily displaced.

Simultaneously with the lowering of the piston 58, the yoke 64 connected to the piston 58 and the first to fourth permanent magnets 56a to 56d connected to the yoke 64 also fall. As a result, the first to fourth permanent magnets 56a to 56d The workpiece 12 approaches. Finally, the piston 58, the yoke 64, and the first to fourth permanent magnets 56a to 56d reach the bottom dead center, thus causing the situation shown in FIG. 4 condition.

When the piston 58 reaches the bottom dead center, the piston 58 abuts the first shock absorber 84 provided on the plate 42. The vibration or collision that occurs at the time of contact is buffered by the first shock absorber 84, and therefore, the vibration of the magnetic chuck 10 can be sufficiently suppressed. In addition, since the damage to the piston 58 or the plate 42 is avoided, the durability of the magnetic chuck 10 can be improved.

When the first to fourth permanent magnets 56a to 56d reach the bottom dead center, since their respective workpiece magnetic attraction surfaces are sufficiently close to the workpiece 12, their magnetic force will be applied to the workpiece 12. More specifically, the work 12 is attracted by the magnetic force of the first to fourth permanent magnets 56a to 56d, and through the bottom wall portion of the magnet cover 16, the first to fourth permanent magnets 56a to 56d attract and hold the work 12. In addition, since the flange 66 of the yoke 64 is used as an auxiliary yoke, the workpiece 12 is more properly attracted and held.

Since the magnet cover 16 is made of paramagnetic metal, the magnet cover 16 cannot be used as a yoke. More specifically, the yoke does not intervene between the first to fourth permanent magnets 56a to 56d and the workpiece 12. Therefore, it is possible to avoid affecting the magnetic circuit formed between the first to fourth permanent magnets 56a to 56d and the workpiece 12.

Furthermore, since the rubber buffer member 28 is provided on the lower end surface of the magnet cover 16, when the work 12 is magnetically attracted to the bottom wall of the magnet cover 16, the buffer member 28 intervenes in the abutment of the work 12. Due to this intervention, and by lengthening the magnetic chuck 10, the stress acting on the magnet cover 16 can be reduced. More specifically, the buffer member 28 performs a buffer function. As a result, it is possible to sufficiently suppress the vibration of the magnetic chuck 10 and avoid damage to the magnet cover 16 or the first to fourth permanent Long magnets 56a to 56d.

There is frictional resistance between the buffer member 28 and the magnetically attracted work 12. Therefore, since the workpiece 12 is difficult to experience sliding against the buffer member 28, the workpiece 10 and the magnetic chuck 10 can be effectively prevented from separating or falling off. In this way, along with this cushioning effect, the cushioning member 28 also performs a non-slip effect. In other words, the cushioning member 28 serves as a non-slip device.

In FIG. 5A and FIG. 5B, the schematic diagram shows the magnetic current that occurs in the conventional technology in which the magnetic attraction surface of the workpiece has only one of the N poles and the area where magnetic saturation occurs. In this case, the magnetic current starting from the N pole constituting the magnetic attraction surface of the workpiece passes through the inside of the workpiece 12 and is directed to the S pole on the back surface. The area where magnetic saturation has occurred is substantially circular.

On the other hand, FIG. 6A and FIG. 6B are schematic diagrams showing the magnetic currents generated when the N pole and the S pole are combined into a pair on the magnetic attraction surface of the workpiece and the area where magnetic saturation occurs. With this configuration, the magnetic current starting from the N pole constituting the magnetic attraction surface of the workpiece passes through the inside of the workpiece 12, and the S pole directed toward the adjacent attraction surface of the workpiece, and the S pole on the back surface thereof. In addition, the magnetic current starting from the N pole on the back surface of the magnetic attraction surface of the workpiece passes through the interior of the workpiece 12 and the S pole pointing to the attraction surface of the workpiece, and passes through the interior of the yoke 64 and is directed to the magnetic attraction surface of the workpiece S pole on the back. As a result, the magnetic saturation occurs with the position in the diameter together with the circle.

Fig. 7 is a schematic diagram showing the magnetic currents generated when the N pole and the S pole are combined into two pairs on the magnetic attraction surface of the workpiece, and the areas where magnetic saturation occurs. In this case, magnetic saturation also occurs at the positions on the two diameters together with the circles. Compared to the previously mentioned configuration, when the N pole and S pole When the combination is formed, it goes without saying that the amount of magnetic current passing through the interior of the workpiece 12 will become larger.

The graph in Figure 8 shows the relationship between the outer diameter of the permanent magnet and the suction force produced thereby, which shows the use of a single permanent magnet and a magnetic chuck on the magnetic attraction surface of the workpiece. A single N-pole formed on it (■ (black square) diagram), using two permanent magnets and a magnetic chuck with a N-pole and an S-pole on the magnetic attraction surface of the workpiece, where the N-pole and S-pole are combined on it Formed as a pair (◆ (black diamond) diagram), and the four permanent magnets using the first to fourth permanent magnets 56a to 56d and the magnetic attraction surface of the work piece are combined to form two pairs of N pole and S pole The magnetic chuck 10 of this specific embodiment (▲ (black triangle) diagram). Needless to say, the materials and holding force of the permanent magnets in each magnetic chuck, and the overall dimensions of the permanent magnets are the same as each other.

It can also be seen from Figure 8 that as the number of magnetic poles on the magnetic attraction surface of the workpiece increases, the attraction force becomes greater. In particular, when the outer diameter of the permanent magnet substantially exceeds 20 mm, or when the thickness of the workpiece 12 becomes small, the difference in suction force becomes significant. From this fact, it is clear that by forming the combination of the N pole and the S pole on the magnetic attraction surface of the workpiece into one or more pairs, and two or more pairs are better, it can exhibit sufficient suction force, thereby even attracting And hold the workpiece 12 made of thin steel plate and being a bulky object. This is because, as described above, due to the combination of the N pole and the S pole on the magnetic attraction surface of the workpiece, the amount of magnetic current passing through the interior of the workpiece 12 becomes larger.

As described above, by forming the combination of the N pole and the S pole on the magnetic attraction surface of the workpiece, the attraction force to the workpiece 12 becomes larger. In particular, according to this tool In an embodiment, the N pole and the S pole are combined into two pairs on the magnetic attraction surface of the workpiece, and therefore, exhibit sufficient suction force.

As a result, according to the present embodiment, assuming that the materials and characteristics of the permanent magnets are the same, when the outer diameters are the same, the attraction force to the workpiece 12 can be increased. This means that even heavier workpieces 12 can be attracted and held.

Alternatively, if the suction force is equivalent, the permanent magnets may be set to a relatively small diameter. In other words, a magnetic chuck 10 with a compact size and scale can be made.

By modifying the number D of protrusions of the cylindrical portion 29b constituting the buffer member 28 from the hollow cylindrical column 25 (magnet cover 16), the suction force to the workpiece 12 can also be adjusted. This point will be explained with reference to FIGS. 9A to 9C and FIG. 10. To facilitate the description, the cushioning members illustrated in FIGS. 9A to 9C are respectively indicated by element symbols 28A, 28B, and 28C.

The cushion members 28A, 28B, and 28C each include the cylindrical portions 29bA, 29bB, and 29bC. In addition, as can be understood from the comparison difference of FIGS. 9A to 9C, the number of protrusions D1, D2, and D3 of the cylindrical portions 29bA, 29bB, and 29bC protruding from the hollow cylindrical column 25 increases in this order. More specifically, among the number of protrusions D1 to D3, the relationship D1<D2<D3 is satisfied.

As described above, when the work 12 is magnetically attracted to the bottom wall of the magnet cover 16, the buffer members 28A to 28C intervene in the work 12. As a result, the distance between the workpiece 12 and the first to fourth permanent magnets 56a to 56d that has reached the bottom dead center becomes larger in the order of the cushion members 28A, 28B, and 28C. This is because, when the workpiece 12 abuts the cylindrical portions 29bA, 29bB, and 29bC protruding from the hollow cylindrical column 25, the workpiece 12 exceeds the suppressed amount and becomes closer to the first One to fourth permanent magnets 56a to 56d.

The graph of FIG. 10 illustrates the relationship between the separation distance between the workpiece 12 and the first to fourth permanent magnets 56a to 56d, and the change in the suction force of the first to fourth permanent magnets 56a to 56d against the workpiece 12. In FIG. 10, the separation distance when the number of protrusions is D1, D2, or D3 is shown as D1, D2, and D3 on the horizontal axis.

It can be understood from Figure 10 that as the separation distance increases, the suction force becomes smaller. The reason is that as the separation distance becomes larger, the attracting forces of the first to fourth permanent magnets 56a to 56d become more difficult to apply to the workpiece 12.

For the reasons described above, for example, by replacing the buffer members 28 having different protrusion numbers D, the suction force to the workpiece 12 can be adjusted appropriately. As a result, for example, when the work piece 12 is an object having a large weight, the suction force can be increased, and the fall of the work piece 12 during transportation can be made more difficult to occur. On the contrary, when the work piece 12 is a light-weight object, in addition to preventing the work piece 12 from falling, the suction force can be made so small that the work piece 12 can be easily released by the magnetic attraction force of the first to fourth permanent magnets 56a to 56d after being transported.

More specifically, when the buffer members 28 are prepared, a plurality of such members protruding from the hollow cylindrical column 25 with a different number of protrusions D are prepared, and diversity is improved, for example, by exchanging the light weight or heavy weight essence, etc. The buffer member 28 of the workpiece 12 to be transported is appropriately matched.

When a plurality of buffer members 28 are used in the above-described manner, members having different protrusion numbers D may each have different colors. More specifically, in the above-described embodiment, there are the buffer member 28A with the protruding number D1, the buffer member 28B with the protruding number D2, and the buffer member 28C with the protruding number D3 It is best to have different colors. Therefore, based on the color of the cushioning member 28, it is possible to quickly confirm the number of cushioning members 28 to be projected. As a result, erroneous attachment of the buffer member 28 can be avoided.

In order to make the colors different, the members for facilitating the identification or confirmation of the buffer members 28 having different protruding numbers D are not particularly limited. For example, any suitable identifier, such as a mark or the like, may be provided so that the appearance of the respective cushion members 28 are different from each other.

As described above, by the robot performing a predetermined operation, after the workpiece 12 has been attracted (magnetically attracted), the distal arm and the magnetic chuck 10 are moved to an appropriate position. The work pieces 12 also move with them.

Next, under the action of the intake and exhaust mechanism, pressurized air is discharged from the upper chamber 62 through the second port 50. At the same time, pressurized air is supplied to the lower chamber 23 by the intake and exhaust mechanism through the first port 37. A part of the pressurized air enters the first intermediate chamber 24 between the flange 66 and the side wall of the first glide hole 22, and further passes through the communication groove 85 and enters the second intermediate chamber 60. Therefore, along with the flange 66 of the yoke 64 receiving the compressed air from the lower chamber 23, the piston 58 also receives the compressed air from the first intermediate chamber 24. Coupled with the negative pressure of the upper chamber 62, the piston 58 will be displaced (raised) away from the plate 42 alone.

According to the present specific embodiment, the third sealing member 90 is provided on the side wall of the piston 58. More specifically, the sealing member is not provided between the yoke 64 and the inner wall of the second intermediate chamber 60. Therefore, in the above process, the member that receives the pressing force of the pressurized air supplied to the upper chamber 62 and the gas pressing force that has moved into the second intermediate chamber 60, in both cases Below, both are piston 58. In addition, although there is an area covered by the shaft 68 on the lower end surface of the piston 58, the flange 66 receives compression from compressed air. More specifically, the pressure receiving area when the piston 58 is descending is substantially the same as the pressure receiving area when the piston 58 is rising. As a result, the reduction in thrust required to raise the piston can be avoided.

With the piston 58 being raised, the yoke 64 and the first to fourth permanent magnets 56a to 56d are raised as a whole. More specifically, the first to fourth permanent magnets 56a to 56d are physically separated from the workpiece 12, and as a result, the magnetic force of the first to fourth permanent magnets 56a to 56d is not applied to the workpiece 12. As a result, the work piece 12 can be released from the magnetic force of the first to fourth permanent magnets 56a to 56d.

The piston 58, the yoke 64, and the first to fourth permanent magnets 56a to 56d finally reach top dead center. In other words, the situation shown in FIG. 3 is restored.

When the piston 58 reaches top dead center, the disk-shaped protrusion 80 of the plate 42 enters the annular recess 72 formed in the flange 66 of the yoke 64. In addition, the second shock absorber 94 provided on the piston 58 abuts the entry member 44 of the joint cover 18. The vibration or collision that occurs at the time of contact is buffered by the second shock absorber 94, and therefore, the vibration of the magnetic chuck 10 can be sufficiently suppressed. In addition, since damage to the piston 58 or the head cover 18 is avoided, the durability of the magnetic chuck 10 can be improved.

In addition, during the progress of the above process, the rotation of the first to fourth permanent magnets 56a to 56d is prevented. This is because, as described above, the first to fourth tie bars 54a to 54d are arranged near the first to fourth permanent magnets 56a to 56d. Since the first to fourth permanent magnets 56a are restricted in this way The rotation to 56d, for example, avoids changing the magnetic flux density near the automatic switch. As a result, it is also possible to prevent such a change in the magnetic current density from causing an automatic switching error operation.

The first to fourth tie rods 54a to 54d serve as members for tightly fastening the head cover 18, the cylinder tube 14 and the magnet cover 16 together, and forming the housing 20. More specifically, since the rotation of the first to fourth permanent magnets 56a to 56d is prevented, there is no need to use other members separate from them. Therefore, the increase in the number of parts can be avoided, and the magnetic chuck 10 can be made more compact, which is also advantageous in terms of cost.

The present invention is not particularly limited to the above specific embodiments, and various modifications can be adopted without departing from the gist and scope of the present invention.

For example, as shown in FIG. 11, two or more U-shaped permanent magnets 100 (three shown in FIG. 11) can be combined, and two or more N poles and two or more S poles can be combined. Resides on the magnetic surface of the workpiece. In addition to this combination, U-shaped permanent magnets 100 (two shown in FIG. 12) may be combined so that their magnetic pole faces are arranged as shown in the bottom view of FIG.

In addition, as shown in FIG. 13, a combination of three or more rod-shaped magnets 102 (three shown in FIG. 13) can form a so-called Halbach array, and a group of N poles and S poles. The combination can be set on the suction surface of the workpiece.

Although in the above specific embodiments, a plurality of permanent magnets are used, a single permanent magnet manufactured by magnetization may be used so that there are two or more pairs of N poles and S poles arranged on the magnetic attraction surface of the workpiece.

As an example of this permanent magnet, as shown in Figure 14 As shown, the magnetization of a predetermined object, such as the cylinder 98, makes the orientation of the magnetic poles U-shaped. This permanent magnet is manufactured by bringing a U-shaped magnet close to a bottom surface of the cylinder 98, thereby forming an N pole and an S pole on the bottom surface. More specifically, the one bottom surface becomes the magnetic surface of the workpiece, and the magnetic pole is not formed on the remaining part of the other bottom surface.

Furthermore, in addition to making the U-shaped permanent magnet close to a bottom surface of the cylinder 98 or the like, by making another U-shaped permanent magnet close to the other bottom surface, as shown in FIG. 15, a permanent magnet is made, in which An N pole and an S pole are formed on a bottom surface used as a magnetic attraction surface of the workpiece, and an S pole and an N pole are formed on the back surface of each other. More specifically, in this case, the magnetization is performed so that the magnetic pole is directed vertically toward the workpiece suction surface.

Furthermore, the first shock absorber 84 may be provided on the lower end surface of the piston 58. On the other hand, the second shock absorber 94 may be provided on the lower end surface of the entrance member 44 of the head cover 18.

In addition, one of the first shock absorber 84 or the second shock absorber 94 may be omitted.

In addition, the buffer member is not particularly limited to the above-mentioned buffer members 28, and 28A to 28C. For example, as shown in FIG. 16, a cushion member 110 including a flange 29c protruding in a radially inward direction may be provided. In this case, on the hollow cylindrical column 25, a first annular groove 112 that is recessed in a radially inward direction is formed, and the flange 29c can be press-fitted to the first annular groove Groove 112.

In addition, as shown in FIGS. 17 and 18, a buffer member 114 or a buffer member having a tapered cross section in the thickness direction may be used 116. In this case, the first annular groove 118 or the first annular groove 120 may be formed on the end surface of the hollow cylindrical column 25 (refer to FIG. 17), or alternatively, may be formed on the side wall (refer to 18 Figure). In both cases, due to the tapered shape, the buffer members 114, 116 can be prevented from being pulled out of the first annular grooves 118, 120.

There is also no limitation to the attachment of the magnet cover 16 that the flange 29a is to be press-fitted into the first annular groove 26 or the like. More specifically, as shown in FIG. 19, the buffer member 122 may be attached to the magnet cover 16 with screws 124. In this case, it is not necessary to form the buffer member 122 in a ring shape, and a plurality of arc-shaped buffer members 122 may be attached.

10‧‧‧Magnetic chuck

22‧‧‧ First glide hole

23‧‧‧Lower chamber

24‧‧‧First middle chamber

26‧‧‧First annular groove

28‧‧‧buffer member

29‧‧‧Slit

29b‧‧‧Cylinder

30‧‧‧Middle flanks

54a to 54d

56a‧‧‧First permanent magnet

56b‧‧‧Second Permanent Magnet

56c‧‧‧third permanent magnet

56d‧‧‧The fourth permanent magnet

Claims (20)

A magnetic chuck (10) which attracts and holds a work piece (12) by a magnetic attraction surface of a work piece (12) by the magnetic force of a plurality of permanent magnets (56a to 56d). 10) comprising: a piston (58) housed in a cylinder tube (14); wherein: the plurality of permanent magnets (56a to 56d) are assembled so that the piston (58) receives a pressure fluid from a When it is displaced by the pressing force, it is displaced in the same direction as the displacement direction of the piston (58); and the plurality of permanent magnets (56a to 56d) are configured to cause a pair of magnetic attraction surfaces on the workpiece Or more pairs of N poles and S poles; an anti-rotation member (54a to 54d) configured to prevent the rotation of the permanent magnets (56a to 56d) is arranged in the cylinder tube (14); the N The pole and the S pole are arranged in contact with each other. The magnetic chuck (10) as described in item 1 of the patent application scope, wherein each of the plurality of permanent magnets (56a to 56d) is assembled so that its magnetization direction is perpendicular to the magnetic attraction surface of the workpiece. The magnetic chuck (10) as described in item 2 of the patent application scope, wherein the N pole and the S pole reside on the magnetic attraction surface of the workpiece to become one pole. The magnetic chuck (10) as described in item 2 of the patent application scope, wherein the N pole and the S pole reside on the magnetic attraction surface of the workpiece as two poles. The magnetic chuck (10) as described in item 2 of the patent application scope, wherein the permanent magnets (56a to 56d) are supported on the piston (58) by a yoke (64). The magnetic chuck (10) as described in item 1 of the patent application scope includes at least Three permanent magnets (102) are arranged as a Haierbeck array containing two permanent magnets (102) whose magnetization direction is perpendicular to the magnetic attraction surface of the workpiece, wherein the N pole of one of the two permanent magnets The S pole of the other of the two permanent magnets is configured to be exposed on the magnetic attraction surface of the workpiece. The magnetic chuck (10) as described in item 1 of the patent application scope, wherein the permanent magnets are composed of U-shaped magnets (100), and the N pole and S pole of each of the U-shaped magnets (100) It is arranged to be exposed on the magnetic attraction surface of the workpiece. The magnetic chuck (10) as described in item 1 of the patent application range, wherein the anti-rotation member (54a to 54d) is made of a ferromagnetic material, and is provided on the magnetic attraction surface of the workpiece adjacent to each other The boundary between the N pole and the S pole. The magnetic chuck (10) as described in item 1 of the patent scope, wherein the anti-rotation member (54a to 54d) is a connecting member assembled to connect the cylinder tube (14) and a head cover (18) (54a to 54d). The magnetic chuck (10) as described in item 1 of the patent scope, wherein a sealing member (90) is provided on a side wall of the piston (58), and between the piston (58) and the cylinder tube (14) A part in between is assembled to be sealed by the sealing member (90). The magnetic chuck (10) as described in item 1 of the patent application scope further includes a magnet cover attached to the cylinder tube (14) and assembled to cover the permanent magnets (56a to 56d) ( 16), wherein a buffer member (28) configured to perform buffering when the permanent magnets (56a to 56d) attract the workpiece (12) is detachably Installed on the magnet cover (16). The magnetic chuck (10) as described in item 11 of the patent application scope, wherein the suction force for the workpiece (12) is configured to be replaced in the buffer member (28) with a difference protruding from the magnet cover (16) The thickness of the other buffer member (28) is changed. A magnetic chuck (10), which attracts and holds the workpiece (12) by a magnetic attraction surface of a workpiece (12) by the magnetic force of a permanent magnet (98), the magnetic chuck (10) includes : A piston (58) housed in a cylinder tube (14); wherein: the permanent magnet (98) is configured such that when the piston (58) receives a pressing force from a pressure fluid and thereby displaces, Displacement in the same direction as the displacement direction of the piston (58); and the permanent magnet (98) is configured to be magnetized to cause one or more pairs of N and S poles to exist on the magnetic attraction surface of the workpiece; An anti-rotation member (54a to 54d) configured to prevent the permanent magnet (98) from rotating is provided in the cylinder tube (14); the N pole and the S pole are arranged in contact with each other. The magnetic chuck (10) as described in item 13 of the patent application scope, wherein the permanent magnet (98) is assembled to be magnetized into a U-shape, and the N pole and the S pole are assembled in the The workpiece is exposed on the magnetic surface. The magnetic chuck (10) as described in item 13 of the patent application scope, wherein the permanent magnet (98) is assembled so that its magnetization direction is perpendicular to the magnetic attraction surface of the workpiece. The magnetic chuck (10) as described in item 13 of the patent application scope, where The anti-rotation members (54a to 54d) are made of a ferromagnetic material, and are provided on the boundary between the N pole and the S pole adjacent to each other on the magnetic attraction surface of the workpiece. The magnetic chuck (10) as described in item 13 of the patent application scope, wherein the anti-rotation member (54a to 54d) is a connecting member assembled to connect the cylinder tube (14) and a head cover (18) (54a to 54d). The magnetic chuck (10) as described in item 13 of the patent application scope, wherein a sealing member (90) is provided on a side wall of the piston (58), and between the piston (58) and the cylinder tube (14) A part in between is assembled to be sealed by the sealing member (90). The magnetic chuck (10) as described in item 13 of the patent application scope further includes a magnet cover (16) attached to the cylinder tube (14) and assembled to cover the permanent magnet (98), A buffer member (28) configured to buffer when the permanent magnet (98) attracts the workpiece (12) is detachably mounted on the magnet cover (16). The magnetic chuck (10) as described in item 19 of the patent application scope, wherein the suction force for the workpiece (12) is configured to be replaced in the buffer member (28) with a difference protruding from the magnet cover (16) The thickness of the other buffer member (28) is changed.

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