Magnet damper for suction pad

Abstract

SOLUTION: An outer circumferential surface 18a and an inner circumferential surface 18b of a fixed magnet 18, which is attached to a body 12, comprise cylindrical surfaces each having a uniform diameter. An outer circumferential surface 34a of a movable magnet 34, which constitutes a movable part 22, comprises a cylindrical surface having a uniform diameter. The inner circumferential surface 34b of the movable magnet comprises a conical curved surface. The fixed magnet and the movable magnet are magnetized in the axial direction, and the axial polarity of the fixed magnet is the same as the axial polarity of the movable magnet.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a magnetic damper for an adsorption pad that relaxes the pressure when the adsorption pad contacts a workpiece.

Background Art

[0002] Generally, in the process of adsorbing a workpiece, an operation of pressing an adsorption pad against the workpiece is required. In order to relieve the pressure applied to the workpiece at this time, an adsorption device provided with a magnetic damper has been conventionally known.

[0003] For example, Patent Document 1 describes an adsorption pad holder including a cylindrical fixed shaft and a cylindrical movable shaft inserted inside the fixed shaft, with magnets arranged on the outer peripheral surface of the movable shaft and the inner peripheral surface of the fixed shaft. The magnets of the movable shaft and the fixed shaft are each divided in the circumferential direction and arranged such that different magnetic poles face each other.

[0004] According to Patent Document 1, when the magnets of the movable shaft and the fixed shaft are displaced in the axial direction, the magnetic field lines generated at the axially overlapping portion of the two magnets do not exert a force in the axial direction, and only the axial component of the oblique magnetic field lines generated at the ends of the two magnets exerts a force in the axial direction. Therefore, even if there is a variation in the stroke when pressing the adsorption pad against the workpiece, it is said that it can be pressed with a constant force.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, it is considered that the axial component of the oblique magnetic field lines generated at the ends of the magnet on the movable shaft and the magnet on the fixed shaft can be regarded as almost constant only within a very limited stroke range.

[0007] If a magnet divided in the circumferential direction is used as in the adsorption pad holder of Patent Document 1, the deviation in the rotational direction between the magnet on the movable shaft and the magnet on the fixed shaft can be suppressed. In order to prevent rotation even when an excessive force acts, it is necessary to provide a mechanical anti-rotation mechanism. When a mechanical anti-rotation mechanism is provided in the adsorption pad holder of Patent Document 1, since the movable shaft moves in the axial direction in a state where a contact pressure is applied in the rotational direction, there is a risk of generating a large sliding resistance.

[0008] An object of the present invention is to solve the above-described problems.

Means for Solving the Problems

[0009] The magnetic damper for an adsorption pad according to the present invention includes a cylindrical body and a movable part supported by the body so as to be displaceable in the axial direction of the body, and relaxes the pressure when the adsorption pad contacts the work by the magnetic force acting between a cylindrical fixed magnet attached to the body and a cylindrical movable magnet constituting the movable part. The outer peripheral surface and the inner peripheral surface of the fixed magnet are composed of cylindrical surfaces having a uniform diameter, the outer peripheral surface of the movable magnet is composed of a cylindrical surface having a uniform diameter, and the inner peripheral surface of the movable magnet is composed of a conical curved surface. The fixed magnet and the movable magnet are magnetized in the axial direction, and the axial polarity of the fixed magnet is the same as the axial polarity of the movable magnet.

Effects of the Invention

[0010] According to the above-described magnet damper for the suction pad, a fixed magnet having a cylindrical surface with a uniform diameter on the outer peripheral surface and the inner peripheral surface and magnetized in the axial direction, and an outer peripheral surface consisting of a cylindrical surface having a uniform diameter, and an inner peripheral surface consisting of a conical curved surface, and a movable magnet magnetized in the axial direction are combined. For this reason, regardless of the displacement amount of the movable part, the axial magnetic force acting between the fixed magnet and the movable magnet can be set to a constant value. Moreover, since no circumferential magnetic force acts between the fixed magnet and the movable magnet, a mechanical anti-rotation mechanism can be provided between the body and the movable part without increasing the sliding resistance of the movable part.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

Figure 3

Figure 4

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Figure 10

DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, a plurality of preferred embodiments of the magnet damper for the suction pad according to the present invention will be described with reference to the accompanying drawings. In the following description, when words related to the vertical direction are used, for convenience, they refer to the directions in the drawings and do not limit the actual arrangement of members and the like.

[0013] (First Embodiment) The magnet damper 10 for the suction pad according to the first embodiment of the present invention will be described with reference to FIGS. 1 to 4.

[0014] As shown in FIGS. 1 and 2, the magnet damper 10 for the suction pad includes a cylindrical body 12 and a movable part 22 supported by the body 12 so as to be displaceable in the axial direction of the body 12. The body 12 is supported by a robot arm or a conveying device (not shown). The movable part 22 includes a piston 24, a movable magnet 34, a pad adapter 36, and a piston tube 38.

[0015] The piston 24 is made of a paramagnetic material such as an aluminum alloy and is slidably disposed inside the body 12. The piston 24 has a hole 26 penetrating axially through the center of the piston 24. The piston 24 has a flange portion 28 protruding radially outward and a shaft portion 30 extending downward from the flange portion 28. The outer shape of the piston 24 when the flange portion 28 of the piston 24 is cut by a plane perpendicular to the axis of the piston 24 is a hexagonal shape with each side curved inward. The cross-section of the flange portion 28 in this embodiment is hexagonal, but any polygonal shape may be used. The flange portion 28 of the piston 24 constitutes a part of a mechanical anti-rotation mechanism described later.

[0016] The movable magnet 34 is disposed below the piston 24 and connected to the piston 24 via the piston tube 38. The movable magnet 34 is configured in a cylindrical shape with a length L1. The movable magnet 34 is magnetized in the axial direction (vertical direction). The outer peripheral surface 34a of the movable magnet 34 consists of a cylindrical surface having a uniform diameter, and the inner peripheral surface 34b of the movable magnet 34 consists of a conical curved surface whose diameter gradually increases from top to bottom. The wall thickness of the movable magnet 34 gradually becomes thinner from top to bottom.

[0017] The pad adapter 36 is configured in a cylindrical shape from a paramagnetic material such as an aluminum alloy. The pad adapter 36 is disposed in contact with the lower end of the movable magnet 34 and connected to the piston 24 via the piston tube 38 together with the movable magnet 34. The pad adapter 36 protrudes downward from the body 12. The protruding amount of the pad adapter 36 changes according to the displacement of the movable part 22. A suction pad (not shown) is attached to the lower end of the pad adapter 36.

[0018] The piston tube 38 is configured in a thin-walled cylindrical shape from a non-magnetic material of austenitic stainless steel. The shaft portion 30 of the piston 24 is press-fitted inside the upper part of the piston tube 38, the movable magnet 34 is press-fitted inside the piston tube 38 over the entire length of the movable magnet 34, and the upper part of the pad adapter 36 is press-fitted inside the lower part of the piston tube 38. Thereby, a vacuum passage 40 for generating a vacuum pressure is formed inside the movable part 22.

[0019] The upper inner surface of the body 12 has a piston guide surface 14 that guides the flange portion 28 of the piston 24. The piston guide surface 14 has recesses 14a that receive convex portions 28a corresponding to the vertices of the polygonal cross-section of the flange portion 28, and together with the flange portion 28, constitutes a mechanical anti-rotation mechanism. The mechanical anti-rotation mechanism composed of the flange portion 28 of the piston 24 and the piston guide surface 14 of the body 12 suppresses the rotation of the movable part 22 around the axis of the body 12.

[0020] A fixed magnet 18 is attached to the lower inner surface of the body 12 via a bush 16. The fixed magnet 18 is configured in a cylindrical shape with a length L2. Both the outer peripheral surface 18a and the inner peripheral surface 18b of the fixed magnet 18 are formed of cylindrical surfaces having a uniform diameter. The fixed magnet 18 is magnetized in the axial direction (vertical direction). The axial polarity of the fixed magnet 18 is the same as the axial polarity of the movable magnet 34. In the present embodiment, the upper portions of the fixed magnet 18 and the movable magnet 34 are N poles, and the lower portions of the fixed magnet 18 and the movable magnet 34 are S poles. The length L2 of the fixed magnet 18 is substantially the same as the length L1 of the movable magnet 34.

[0021] The piston tube 38 is inserted inside the fixed magnet 18. A ring-shaped stopper 20 is attached to the inner surface at the axial center of the body 12 via a groove. When the flange portion 28 of the piston 24 abuts against the stopper 20, the downward displacement of the movable portion 22 is restricted. When the flange portion 28 of the piston 24 abuts against the stopper 20, the protruding amount of the pad adapter 36 becomes maximum. At this time, the length by which the fixed magnet 18 and the movable magnet 34 overlap each other in the axial direction is minimum.

[0022] A pipe adapter 42 is attached to the upper portion of the body 12. The pipe adapter 42 includes a main body portion 44 and an elongated tube-shaped vacuum introduction portion 46 extending downward from the main body portion 44. A pipe (not shown) extending from a vacuum generating device (not shown) is connected to the main body portion 44 of the pipe adapter 42. The vacuum introduction portion 46 of the pipe adapter 42 is inserted into the hole portion 26 of the piston 24. An O-ring 32 attached to the hole portion 26 of the piston 24 is in sliding contact with the vacuum introduction portion 46 of the pipe adapter 42. The vacuum pressure is introduced into the vacuum passage 40 of the movable portion 22 through the pipe adapter 42, and it becomes possible to adsorb a workpiece by an adsorption pad attached to the pad adapter 36.

[0023] As shown in FIG. 3, when the flange portion 28 of the piston 24 abuts against the main body portion 44 of the pipe adapter 42, the upward displacement of the movable portion 22 is restricted. When the flange portion 28 of the piston 24 abuts against the pipe adapter 42, the protruding amount of the pad adapter 36 becomes minimum. At this time, the length by which the fixed magnet 18 and the movable magnet 34 overlap each other in the axial direction is maximum. The movable portion 22 can be displaced between the position where the flange portion 28 of the piston 24 abuts against the stopper 20 and the position where the flange portion 28 of the piston 24 abuts against the pipe adapter 42.

[0024] The side surface of the main body portion 44 of the pipe adapter 42 has a groove portion 44a for discharging pressure. The pressure in the back pressure chamber 48 partitioned by the body 12, the pipe adapter 42, and the flange portion 28 of the piston 24 is always kept at atmospheric pressure by the action of the groove portion 44a of the pipe adapter 42. Therefore, even if the movable portion 22 is displaced, the pressure in the back pressure chamber 48 does not affect the movement of the movable portion 22.

[0025] When a vacuum pressure is introduced into the vacuum passage 40 of the movable portion 22, the balance of the vertical forces due to the atmospheric pressure acting on the movable portion 22 is broken, and the movable portion 22 may be displaced upward unintentionally. To address this problem, the outer diameter of the vacuum introduction portion 46 of the pipe adapter 42 is set to a relatively small value. In the present embodiment, the outer diameter of the vacuum introduction portion 46 is about one-fifth of the outer diameter of the body 12.

[0026] The movable magnet 34 is biased downward by the magnetic force acting axially between the movable magnet 34 and the fixed magnet 18. When no external force acts on the pad adapter 36, the piston 24 abuts against the stopper 20. The magnetic force acting axially between the fixed magnet 18 and the movable magnet 34 appears as a force that tries to separate the upper end of the movable magnet 34 from the upper end of the fixed magnet 18 and a force that tries to bring the upper end of the movable magnet 34 closer to the lower end of the fixed magnet 18.

[0027] By combining the fixed magnet 18 and the movable magnet 34 having the above-described shapes, the magnetic force acting axially between the fixed magnet 18 and the movable magnet 34 can be made a constant value regardless of the displacement amount of the movable part 22. This constant value is set to a magnitude that does not damage the workpiece. Also, since the magnetic force is constant, the load applied to the workpiece does not fluctuate.

[0028] FIG. 4 is a graph showing the magnetic force acting axially between the fixed magnet 18 and the movable magnet 34, compared with the case where the movable magnet 34 is configured in a cylindrical shape. The horizontal axis represents the displacement amount of the movable part 22. Specifically, with the position of the movable part 22 when the protruding amount of the pad adapter 36 is maximum as a reference position, it represents the amount by which the movable part 22 is displaced upward from the reference position. The vertical axis represents the magnetic force acting axially between the fixed magnet 18 and the movable magnet 34. The solid line indicates the magnetic force in this embodiment, and the dotted line indicates the magnetic force in the case where the movable magnet 34 is configured in a cylindrical shape.

[0029] As understood from FIG. 4, when the movable magnet 34 is configured in a cylindrical shape, the magnetic force acting axially between the fixed magnet 18 and the movable magnet 34 is not constant, and particularly in the region where the displacement of the movable part 22 is large, there is a tendency to increase as the displacement amount of the movable part 22 increases. For this reason, when the displacement of the movable part 22 becomes large, the force with which the movable magnet 34 is biased downward becomes large. In contrast, in this embodiment, in all displacement regions of the movable part 22, the magnetic force acting axially between the fixed magnet 18 and the movable magnet 34 is a constant value.

[0030] Next, the operation when the workpiece is adsorbed by the adsorption pad magnet damper 10 will be described. When a command to adsorb the workpiece is issued, the robot arm or the transfer device is driven, and the adsorption pad magnet damper 10 to which the adsorption pad is attached approaches the workpiece.

[0031] The robot arm or the transfer device is driven and controlled so that the magnet damper 10 for the suction pad reaches the target position. In this case, the target position of the magnet damper 10 for the suction pad is set such that while the suction pad is in contact with the workpiece, the protruding amount of the pad adapter 36 is set to a size intermediate between the maximum value and the minimum value. After the suction pad comes into contact with the workpiece and the magnet damper 10 for the suction pad is displaced to the target position, a vacuum pressure is introduced into the vacuum passage 40. Thereby, the force for pressing the workpiece can be set to the above-described constant value. After the vacuum pressure introduced into the vacuum passage 40 acts on the workpiece and the suction holding state of the workpiece is ensured, the force for pressing the workpiece is released, and the magnet damper 10 for the suction pad that has suction-held the workpiece moves to a predetermined location.

[0032] Even if the accuracy of the control for causing the magnet damper 10 for the suction pad to reach the target position is low, and even if there are variations in the size of the workpiece, there is no variation in the magnitude of the force for pressing the workpiece, and the workpiece can be pressed with a stable force.

[0033] In the present embodiment, a mechanical anti-rotation mechanism is constituted by the flange portion 28 of the piston 24 and the piston guide surface 14 of the body 12, and the piston guide surface 14 has recesses 14a for receiving convex portions 28a corresponding to the respective vertices of the polygonal cross-section of the flange portion 28. However, the mechanical anti-rotation mechanism is not limited to such a configuration.

[0034] According to the present embodiment, regardless of the displacement amount of the movable portion 22, the axial magnetic force acting between the fixed magnet 18 and the movable magnet 34 can be set to a constant value. Moreover, a mechanical anti-rotation mechanism can be provided between the body 12 and the movable portion 22 without increasing the sliding resistance of the movable portion 22.

[0035] (Second Embodiment) The magnetic damper 50 for the suction pad according to the second embodiment of the present invention will be described with reference to FIGS. 5 to 7. In addition, the same or equivalent components as those of the magnetic damper 10 for the suction pad according to the first embodiment are denoted by the same reference numerals, and detailed descriptions may be omitted.

[0036] As shown in FIGS. 5 and 6, the magnetic damper 50 for the suction pad includes a cylindrical body 12 and a movable part 22 supported by the body 12 so as to be displaceable in the axial direction of the body 12. The movable part 22 includes a piston 54, a movable magnet 34, a pad adapter 36, and a piston tube 38.

[0037] The movable magnet 34 is magnetized in the axial direction. The outer peripheral surface 34a of the movable magnet 34 is a cylindrical surface having a uniform diameter, and the inner peripheral surface 34b of the movable magnet 34 is a conical curved surface whose diameter gradually increases from top to bottom. The fixed magnet 18 attached to the body 12 is magnetized in the axial direction. Both the outer peripheral surface 18a and the inner peripheral surface 18b of the fixed magnet 18 are cylindrical surfaces having a uniform diameter. The axial polarity of the fixed magnet 18 is the same as the axial polarity of the movable magnet 34.

[0038] The piston 54 has a hole 56 penetrating through the center of the piston 54 in the axial direction. The piston 54 has a flange portion 58 protruding radially outward, a lower shaft portion 60 extending downward from the flange portion 58, and an upper shaft portion 62 extending upward from the flange portion 58. The outer shape when the flange portion 58 of the piston 54 is cut by a plane perpendicular to the axis of the piston 54 is a hexagonal shape with each side curved inward. The upper inner surface of the body 12 has a piston guide surface 14 for guiding the flange portion 58 of the piston 54. The piston guide surface 14 has recesses 14a for receiving convex portions 58a corresponding to the vertices of the polygonal cross-section of the flange portion 58, and together with the flange portion 58, constitutes a mechanical anti-rotation mechanism.

[0039] A ring-shaped guide bush 64 is attached to the upper end of the body 12. The upper shaft portion 62 of the piston 54 is inserted through the guide bush 64, and a part of the upper shaft portion 62 protrudes upward from the guide bush 64. A pipe (not shown) extending from a vacuum generating device (not shown) is connected to the upper shaft portion 62 of the piston 54. The protruding amount of the upper shaft portion 62 of the piston 54 changes according to the displacement of the movable portion 22. The pipe is displaced integrally with the movable portion 22.

[0040] The lower shaft portion 60 of the piston 54 is press-fitted inside the upper part of the piston tube 38, the movable magnet 34 is press-fitted inside the piston tube 38 over the entire length of the movable magnet 34, and the upper part of the pad adapter 36 is press-fitted inside the lower part of the piston tube 38. Thereby, a vacuum passage 66 for generating a vacuum pressure is formed inside the movable portion 22. The vacuum pressure from a vacuum generating device (not shown) is introduced into the vacuum passage 66 of the movable portion 22.

[0041] As shown in FIG. 5, when the flange portion 58 of the piston 54 abuts against the stopper 20, the protruding amount of the pad adapter 36 becomes maximum. As shown in FIG. 7, when the flange portion 58 of the piston 54 abuts against the guide bush 64, the protruding amount of the pad adapter 36 becomes minimum.

[0042] (Third Embodiment) The magnetic damper 70 for an adsorption pad according to the third embodiment of the present invention will be described with reference to FIGS. 8 to 10. In addition, the same reference numerals are given to the same or equivalent components as those of the magnetic damper 10 for an adsorption pad according to the first embodiment, and detailed description may be omitted.

[0043] As shown in FIGS. 8 and 9, the magnetic damper 70 for an adsorption pad includes a cylindrical body 72 and a movable portion 22 supported by the body 72 so as to be displaceable in the axial direction of the body 72. The movable portion 22 includes a piston 78, a movable magnet 34, a pad adapter 36, and a piston tube 38.

[0044] The body 72 has a first groove portion 72a, a pair of second groove portions 72b and 72c, and a third groove portion 72d. The first groove portion 72a, the pair of second groove portions 72b and 72c, and the third groove portion 72d surround the outer peripheral surface of the body 72. One of the second groove portions 72b is formed above the first groove portion 72a, and the other second groove portion 72c is formed below the first groove portion 72a. The third groove portion 72d is formed below the other second groove portion 72c. The body 72 has a pair of vacuum introduction holes 74 that extend from the inner peripheral surface of the body 72 to the bottom surface of the first groove portion 72a.

[0045] A pipe (not shown) extending from a vacuum generating device (not shown) is connected to the vacuum introduction holes 74. Seal rings 94 are mounted in the second groove portions 72b and 72c. The seal rings 94 prevent a decrease in the vacuum pressure when the vacuum pressure is supplied from the vacuum generating device to the vacuum introduction holes 74. The body 72 is supported by a robot arm or a transfer device (not shown) using a set screw (not shown) that engages with the third groove portion 72d.

[0046] The movable magnet 34 is magnetized in the axial direction. The outer peripheral surface 34a of the movable magnet 34 consists of a cylindrical surface having a uniform diameter, and the inner peripheral surface 34b of the movable magnet 34 consists of a conical curved surface whose diameter gradually increases from top to bottom. The fixed magnet 18 attached to the body 72 is magnetized in the axial direction. Both the outer peripheral surface 18a and the inner peripheral surface 18b of the fixed magnet 18 consist of cylindrical surfaces having a uniform diameter. The axial polarity of the fixed magnet 18 is the same as the axial polarity of the movable magnet 34.

[0047] The piston 78 has a flange portion 80 that protrudes radially outward, a lower shaft portion 82 that extends downward from the flange portion 80, and an upper shaft portion 84 that extends upward from the flange portion 80. When the flange portion 80 of the piston 78 is cut by a plane perpendicular to the axis of the piston 78, the outer shape is a hexagonal shape with each side curved inward. The inner surface of the body 72 has a piston guide surface 76 that guides the flange portion 80 of the piston 78. The piston guide surface 76 has recesses 76a that receive convex portions 80a corresponding to the vertices of the polygonal cross-section of the flange portion 80, and together with the flange portion 80, constitutes a mechanical anti-rotation mechanism.

[0048] The piston 78 has a bottomed vertical hole 86 that opens to the lower surface of the piston 78 and a pair of horizontal holes 88 that open to the side surface of the flange portion 80 of the piston 78. The vertical hole 86 of the piston 78 is connected to the horizontal hole 88 of the piston 78. The horizontal hole 88 of the piston 78 communicates with the vacuum introduction hole 74 of the body 72 through the gap between the body 72 and the piston 78. A ring-shaped guide bush 90 is attached to the upper end of the body 72. The upper shaft portion 84 of the piston 78 is inserted through the guide bush 90, and a part of the upper shaft portion 84 protrudes upward from the guide bush 90.

[0049] The lower shaft portion 82 of the piston 78 is press-fitted inside the upper part of the piston tube 38, the movable magnet 34 is press-fitted inside the piston tube 38 over the entire length of the movable magnet 34, and the upper part of the pad adapter 36 is press-fitted inside the lower part of the piston tube 38. A vacuum passage 92 including the vertical hole 86 and the horizontal hole 88 of the piston 78 is formed inside the movable part 22. The vacuum pressure from a vacuum generating device (not shown) is introduced into the vacuum passage 92 of the movable part 22 through the vacuum introduction hole 74 of the body 72.

[0050] As shown in FIG. 8, when the flange portion 80 of the piston 78 abuts against the stopper 20, the protruding amount of the pad adapter 36 becomes maximum. As shown in FIG. 10, when the flange portion 80 of the piston 78 abuts against the guide bush 90, the protruding amount of the pad adapter 36 becomes minimum.

[0051] In the third embodiment, the body 72 includes a third groove portion 72d for supporting a robot arm or a transfer device. However, a groove portion similar to this may be formed in the body 12 in the first embodiment.

[0052] The magnet damper for the suction pad according to the present invention is not limited to the above-described embodiments, and various configurations can be adopted without departing from the gist of the present invention.

Explanation of Reference Numerals

[0053] 10, 50, 70... Magnet damper for suction pad 12, 72... Body 14, 76... Piston guide surface 14a, 76a... Concave portion 18... Fixed magnet 20... Stopper 22... Movable part 24, 54, 78... Piston 26... Hole 28, 58, 80... Flange portion 28a, 58a, 80a... Protrusion 32... O-ring 34... Movable magnet 36... Pad adapter 38... Piston tube 40, 66, 92... Vacuum passage 42... Pipe adapter 44... Main body portion 44a... Groove 46... Vacuum introduction portion 48... Back pressure chamber 62... Upper shaft portion (shaft portion) 64... Guide bush 74... Vacuum introduction hole 86... Vertical hole 88... Horizontal hole

Claims

1. An adsorption pad magnetic damper that includes a cylindrical body and a movable part supported by the body so as to be displaceable in the axial direction of the body, and that mitigates the pressure when the adsorption pad contacts the workpiece by the magnetic force acting between a cylindrical fixed magnet attached to the body and a cylindrical movable magnet that constitutes the movable part, wherein the outer peripheral surface and the inner peripheral surface of the fixed magnet are each composed of a cylindrical surface having a uniform diameter, the outer peripheral surface of the movable magnet is composed of a cylindrical surface having a uniform diameter, the inner peripheral surface of the movable magnet is composed of a conical curved surface, the fixed magnet and the movable magnet are magnetized in the axial direction, and the axial polarity of the fixed magnet is the same as the axial polarity of the movable magnet.

2. The adsorption pad magnetic damper according to claim 1, wherein the magnetic force acting axially between the fixed magnet and the movable magnet is constant regardless of the displacement of the movable part.

3. The adsorption pad magnetic damper according to claim 1, which includes a mechanical anti-rotation mechanism that suppresses rotation of the movable part around the axis of the body.

4. The adsorption pad magnetic damper according to claim 3, wherein the movable part includes a piston having a flange portion, the cross section of the flange portion is polygonal, the piston guide surface of the body has recesses that receive convex portions corresponding to the respective vertices of the polygonal cross section of the flange portion, and the mechanical anti-rotation mechanism is composed of the flange portion and the piston guide surface.

5. The adsorption pad magnetic damper according to claim 1, wherein the movable part includes a piston and a pad adapter, the pad adapter protrudes from the body, and the displacement of the movable part in the direction in which the protruding amount of the pad adapter increases is restricted by the piston abutting against a stopper attached to the body.

6. The adsorption pad magnetic damper according to claim 1, The movable part includes a piston, a pad adapter, and a piston tube. The movable magnet and the pad adapter are connected to the piston via the piston tube, and a vacuum passage is formed inside the movable part for the magnet damper of the suction pad.

7. In the magnet damper for a suction pad according to Claim 1, the movable part includes a piston, a pipe adapter is attached to the body, and the pipe adapter includes a main body part to which a pipe is attached and a vacuum introduction part inserted into the hole of the piston via an O-ring for the magnet damper of the suction pad.

8. In the magnet damper for a suction pad according to Claim 7, the pipe adapter has a groove part for releasing the pressure of a back pressure chamber partitioned by the body, the pipe adapter, and the piston for the magnet damper of the suction pad.

9. In the magnet damper for a suction pad according to Claim 1, the movable part includes a piston, a guide bush is attached to the body, the piston includes a shaft part to which a pipe is connected, and the shaft part is inserted into the guide bush for the magnet damper of the suction pad.

10. In the magnet damper for a suction pad according to Claim 1, the movable part includes a piston, the piston has a bottomed vertical hole and a horizontal hole opening on the side surface of the piston, the vertical hole is connected to the horizontal hole, the body has a vacuum introduction hole, and the horizontal hole communicates with the vacuum introduction hole for the magnet damper of the suction pad.

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