Floating Unit

Abstract

To provide a floating unit capable of reducing the size of the entire system for operating the floating unit. [Solution] The floating unit 1 is a floating unit including a fixed block, a vertically movable block configured to be slidable in the vertical direction, and a horizontally movable block at least a portion of which is made of a magnetic material and configured to be slidable in the horizontal direction. The vertically movable block has a permanent electromagnetic holder configured to be able to attract an object to be attracted when in an attraction ON state, and to be able to detach the attracted object when in an attraction OFF state. When the permanent electromagnetic holder is in an attraction ON state, the vertically movable block is attracted to the horizontally movable block and stops the horizontally movable block, and when the permanent electromagnetic holder is in an attraction OFF state, the vertically movable block is separated from the horizontally movable block, and the horizontally movable block is in a movable state.

Description

[Technical field]

[0001] The present invention relates to a floating unit, and in particular to a floating unit that is connected between a robot hand and a chuck to correct any misalignment between the central axis of the hole in the part and the central axis of the workpiece, for example when inserting or pressing a workpiece such as a shaft member into a hole in a part having a hole formed therein, in order to reliably insert or press-fit the workpiece into the hole in the part. [Background technology]

[0002] 2. Description of the Related Art Conventionally, a floating unit for reliably inserting or press-fitting a workpiece into a hole in a component is known from the perspective of the floating unit described in Patent Document 1.

[0003] The floating unit described in Patent Document 1 includes a fixed block to which a fluid is supplied from the outside and in which a first space is formed inside, an intermediate block which is partially housed in the first space and configured to be slidable in the direction in which the bottom surface extends and in which a second space is formed inside, and a movable block which is partially housed in the second space and configured to be movable toward and away from the fixed block (hereinafter, the intermediate block and the movable block are collectively referred to as the "horizontally movable block.") The floating unit is configured to restrain the horizontally movable block by utilizing the pressure of the fluid supplied from the outside.

[0004] Incidentally, Patent Document 2 discloses a permanent electromagnetic holder that has an attraction surface for an object to be attracted, is configured to be able to attract the object to be attracted when the attraction is in an ON state, and is configured to be able to detach the attracted object when the attraction is in an OFF state, and includes a first magnet, a second magnet, and a coil, and the operation of switching the attraction ON / OFF state is performed by instantaneously passing electricity through the coil when switching the attraction ON / OFF state to switch the magnetization direction of the first magnet. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2019-217572 A [Patent Document 2] International Publication No. 2021 / 206074 Summary of the Invention [Problem to be solved by the invention]

[0006] The floating unit described in Patent Document 1 requires the connection of a pipe for the fluid to flow in from the outside and a pipe for the fluid to flow out to the outside, and also requires a separate device to pressurize the fluid, which creates the problem that the entire system for operating the floating unit becomes large-scale.

[0007] Therefore, the present invention has been devised in consideration of the above problems, and has an object to provide a floating unit that can reduce the size of the entire system for operating the floating unit. [Means for solving the problem]

[0008] The inventors of the present application have developed a floating unit that uses the permanent electromagnetic holder described in Patent Document 2 to switch the horizontally movable block between a movable state and a restrained state using electricity.

[0009] The specific configuration of the invention relating to the floating unit is as follows.

[0010] The floating unit according to the present invention is a floating unit comprising: a fixed block having a bottom surface and an accommodation space formed therein, a vertically movable block accommodated in the accommodation space of the fixed block and configured to be slidable in the vertical direction, and a horizontally movable block having a top surface, at least a portion of which is accommodated in the accommodation space of the fixed block, disposed on the opposite side of the bottom surface from the vertically movable block, at least a portion of which is made of a magnetic material and configured to be slidable in the horizontal direction, the circumferential direction, or both. The vertically movable block has a permanent electromagnetic holder having an attraction surface for an object to be attracted, configured to be able to attract the object to be attracted in an attraction ON state and to be able to detach the attracted object to be attracted in an attraction OFF state, the permanent electromagnetic holder comprising a first magnet, a second magnet, and a coil, and the attraction ON / OFF state switching operation is performed by instantaneously passing current through the coil to switch the magnetization direction of the first magnet when switching the attraction ON / OFF state. Then, when current is instantaneously applied to the permanent electromagnetic holder, which is in the suction OFF state, and the permanent electromagnetic holder changes to the suction ON state, the vertical movable block is attracted to the horizontally movable block and stops the horizontally movable block, and when current is instantaneously applied to the permanent electromagnetic holder, which is in the suction ON state, and the permanent electromagnetic holder changes to the suction OFF state, the vertical movable block separates from the horizontally movable block and the horizontally movable block becomes movable.

[0011] According to the floating unit of the present invention, the horizontally movable block's restrained state and movable state are switched by a permanent electromagnetic holder that is housed inside the floating unit (inside the storage space of the fixed block) and driven by electricity, so there is no need to connect pipes to the outside of the floating unit or to provide a separate device for pressurizing the fluid, and the entire system for operating the floating unit can be made smaller.

[0012] The floating unit of the present invention may be configured such that, in addition to the permanent electromagnetic holder, the vertical movable block has a accommodating piston that accommodates the permanent electromagnetic holder with the suction surface of the permanent electromagnetic holder exposed on the opposite side of the bottom surface, and the horizontally movable block has an suction plate made of a magnetic material that can be attracted to the permanent electromagnetic holder, and a ball contact plate that is arranged on the opposite side of the bottom surface from the suction plate, is integrally connected to the suction plate, and is supported on the fixed block so as to be slidable in the horizontal direction, the circumferential direction, or both.

[0013] According to the floating unit of the present invention, the suction surface of the permanent electromagnetic holder of the upper and lower movable blocks is exposed on the opposite side of the bottom surface of the accommodating piston, so that the suction surface of the permanent electromagnetic holder can be adsorbed so as to come into surface contact with the suction plate, thereby more reliably restraining the horizontally movable block.

[0014] The floating unit of the present invention may be configured such that the horizontally movable block further has a center pin protruding from the suction plate toward the bottom surface, and the vertically movable block further has a center guide having a tapered recess that increases in diameter toward the opposite side of the bottom surface, and when the vertically movable block is adsorbed to the horizontally movable block, the tip of the center pin is guided by the tapered shape of the recess of the center guide, thereby correcting any positional deviation in the horizontal or circumferential direction or both of the directions of the axis of the horizontally movable block relative to the axis of the fixed block.

[0015] According to the floating unit of the present invention, the attraction force of the permanent electromagnetic holder can be utilized to correct the positional deviation of the axis of the horizontally movable block relative to the axis of the fixed block in the horizontal direction, the circumferential direction, or both.

[0016] The floating unit of the present invention may be configured such that the horizontally movable block further has an auxiliary pin protruding toward the bottom side from the suction plate, and the vertically movable block further has an auxiliary pin guide having a recess into which the tip of the auxiliary pin can fit, and when the vertically movable block is adsorbed to the horizontally movable block, the tip of the auxiliary pin fits into the recess of the auxiliary pin guide.

[0017] According to the floating unit of the present invention, in addition to the holding force of the horizontally movable block due to the frictional force generated when the suction surface of the permanent electromagnetic holder is attracted to the suction plate, a further holding force of the horizontally movable block is generated by the tip of the auxiliary pin fitting into the auxiliary pin guide, so that the horizontally movable block can be more reliably restrained. Effect of the Invention

[0018] Therefore, according to the floating unit of the present invention, the entire system for operating the floating unit can be made smaller. [Brief description of the drawings]

[0019] [Figure 1] 1 is a top view of a floating unit according to an embodiment of the present invention; [Diagram 2] 1 is a bottom view of a floating unit according to an embodiment of the present invention; [Diagram 3] 3 is a cross-sectional view taken along line III-III in FIG. 1, showing a state in which the vertically movable block is not attached to the horizontally movable block and the horizontally movable block slides horizontally relative to the fixed block. FIG. [Figure 4] 3 is a cross-sectional view taken along line III-III in FIG. 1, showing a state in which the positional deviation of the axis of the horizontally movable block relative to the axis of the fixed block is corrected as a result of the vertically movable block being attached to the horizontally movable block. [Diagram 5] 2 is a cross-sectional view taken along line VV in FIG. 1, showing a state in which the vertically movable block is not attached to the horizontally movable block. FIG. [Figure 6] 1, showing a state in which the auxiliary pin fits into a recess of the auxiliary pin guide as a result of the vertical movable block being attracted to the horizontally movable block. FIG. [Figure 7] 5 is a schematic cross-sectional view showing a rotation restriction pin and the like of the floating unit according to the embodiment of the present invention. FIG. [Figure 8] 5 is a schematic cross-sectional view showing an accommodation space formed by a fixed block of the floating unit according to the embodiment of the present invention. FIG. [Figure 9] 1 is a top view of a lock cylinder of a fixed block of a floating unit according to an embodiment of the present invention. FIG. [Figure 10] 1 is a bottom view of a lock cylinder of a fixed block of a floating unit according to an embodiment of the present invention. FIG. [Figure 11] 10 is a cross-sectional view taken along line XI-XI of FIG. 9. [Figure 12] 10 is a cross-sectional view taken along line XII-XII in FIG. 9. [Figure 13] 10 is a cross-sectional view taken along line XIII-XIII in FIG. 9. [Figure 14] FIG. 4 is a top view of a piston guide of a fixed block of the floating unit according to the embodiment of the present invention. [Figure 15] 15 is a cross-sectional view taken along line XV-XV of FIG. 14. [Figure 16] 16 is a cross-sectional view taken along line XVI-XVI in FIG. 14. [Figure 17] 1 is a top view of a main body of a fixed block of a floating unit according to an embodiment of the present invention; FIG. [Figure 18] 1 is a bottom view of a main body of a fixed block of a floating unit according to an embodiment of the present invention. FIG. [Figure 19] 19 is a cross-sectional view taken along line XIX-XIX in FIG. 17. [Figure 20] 18 is a cross-sectional view taken along line XX-XX in FIG. 17. [Figure 21] 18 is a cross-sectional view taken along line XXI-XXI of FIG. 17. [Figure 22]5 is a vertical cross-sectional view showing a rotation restriction pin of a fixed block of the floating unit according to the embodiment of the present invention. FIG. [Figure 23] 2A and 2B are diagrams showing the ball contact plate (upper) of the fixed block of the floating unit in the embodiment of the present invention, where (a) is a diagram seen from above and (b) is a cross-sectional view taken along line XXIII-XXIII in (a). [Figure 24] 4 is a vertical cross-sectional view showing a ball contact plate (lower) of a fixed block of a floating unit according to an embodiment of the present invention. FIG. [Diagram 25] 2A and 2B are diagrams showing a ball retainer of a fixed block of a floating unit according to an embodiment of the present invention, where (a) is a diagram seen from above, and (b) is a cross-sectional view taken along line XXV-XXV of (a). [Figure 26] 1 is a top view of a housing piston of a vertically movable block of a floating unit according to an embodiment of the present invention; FIG. [Figure 27] 1 is a bottom view of a housing piston of a vertically movable block of a floating unit according to an embodiment of the present invention; FIG. [Figure 28] 27 is a cross-sectional view taken along line XXVIII-XXVIII in FIG. 26. [Figure 29] 29 is a cross-sectional view taken along line XXIX-XXIX in FIG. 26. [Diagram 30] This is a cross-sectional view taken along line XXX-XXX in Figure 26. [Diagram 31] 5 is a vertical cross-sectional view of a center guide of a vertically movable block of the floating unit according to the embodiment of the present invention. FIG. [Diagram 32] 5 is a vertical cross-sectional view of an auxiliary pin guide of a vertically movable block of the floating unit according to the embodiment of the present invention. FIG. [Diagram 33] 13 is a top view of the ball contact plate (center) of the horizontally movable block of the floating unit according to the embodiment of the present invention. FIG. [Diagram 34] This is a cross-sectional view taken along line XXXIV-XXXIV in Figure 33. [Diagram 35] This is a cross-sectional view taken along line XXXV-XXXV in Figure 33. [Diagram 36] This is a cross-sectional view taken along line XXXVI-XXXVI in Figure 33. [Figure 37] 1 is a top view of an adsorption plate of a horizontally movable block of a floating unit according to an embodiment of the present invention; FIG. [Figure 38] This is a cross-sectional view taken along line XXXVIII-XXXVIII in Figure 37. [Figure 39] This is a cross-sectional view taken along line XXXIX-XXXIX in Figure 37. [Diagram 40] 38 is a cross-sectional view taken along the line XL-XL of FIG. 37. [Diagram 41] 5 is a vertical cross-sectional view of a center pin of a horizontally movable block of the floating unit according to the embodiment of the present invention. FIG. [Diagram 42] 5 is a vertical cross-sectional view of an auxiliary pin of a horizontally movable block of the floating unit according to the embodiment of the present invention. FIG. [Diagram 43] 1 is a top view of a top plate of a horizontally movable block of a floating unit according to an embodiment of the present invention; FIG. [Diagram 44] 1 is a bottom view of a top plate of a horizontally movable block of a floating unit according to an embodiment of the present invention. FIG. [Diagram 45] 44 is a cross-sectional view taken along line XLV-XLV of FIG. 43. [Figure 46] This is a cross-sectional view taken along line XLVI-XLVI in Figure 43. [Figure 47] This is a cross-sectional view taken along line XLVII-XLVII in Figure 44. [Figure 48] FIG. 11 is a schematic cross-sectional view of a floating unit according to a modified example of the present invention, showing a state in which the vertically movable block is not adsorbed to the horizontally movable block and the horizontally movable block slides horizontally relative to the fixed block. [Figure 49] FIG. 11 is a schematic cross-sectional view of a floating unit according to a modified example of the present invention, showing a state in which the vertically movable block is adsorbed to the horizontally movable block while the horizontally movable block slides horizontally relative to the fixed block; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] Hereinafter, a floating unit according to an embodiment of the present invention will be described in detail with reference to the drawings. The terms and directions used in the following description are defined as follows. The term "robot hand" corresponds to the arm of an industrial robot. The term "workpiece" refers to a part that is transferred to the robot hand and inserted or pressed into a hole in a target part. The term "chuck" refers to a part that grips or holds the workpiece. The term "bottom surface" refers to a surface where the floating unit is connected to the robot hand. The term "top surface" refers to a surface where the floating unit is connected to the chuck. In all drawings, the bottom surface is illustrated as the upper side and the top surface is illustrated as the lower side, and the bottom surface direction (towards the bottom surface) is referred to as "upward" or "upward", and the top surface direction (the direction opposite to the bottom surface) is referred to as "downward" or "downward". That is, in all drawings, the top plate of the floating unit is illustrated facing downward. In addition, the radially outer side as viewed from the center of the bottom surface of the floating unit is referred to as the "outer side", and the radially inner side is referred to as the "inner side". In addition, the circumferential direction as viewed from the center of the bottom surface of the floating unit may be referred to as the "θ direction". In this specification, "insertion" includes inserting a member into a hole with almost no resistance and pressing a member into a hole by applying pressure while receiving frictional resistance. Note that the embodiment shown below is an example of the present invention and does not limit the technical scope of the present invention.

[0021] The floating unit 1 is connected between a robot hand (not shown) and a chuck (not shown) to correct a deviation between the central axis of the hole of the component and the central axis of the workpiece when, for example, inserting a workpiece such as an axial member into a hole of a component having a hole formed therein, and to reliably insert the workpiece into the hole of the component. The floating unit 1 is formed so that its outer shape is substantially cylindrical. The floating unit 1 is used with its bottom and top surfaces facing in the vertical direction. The configuration and operation of the floating unit 1 will be described below.

[0022] As shown in Figures 3 to 7 (hereinafter referred to as "Figure 3 etc."), the floating unit 1 includes a fixed block 100 connected to a robot hand via a flange (not shown) and fixed to the robot hand, a vertically movable block 400 housed in the fixed block 100, and a horizontally movable block 700 arranged on the side farther from the robot hand than the vertically movable block 400 (the opposite side to the bottom surface 110p). The fixed block 100, the vertically movable block 400, and the horizontally movable block 700 are stacked to form a substantially cylindrical floating unit 1. Each component will be described in detail below.

[0023] (Fixed Block) The fixed block 100 is located on the robot hand side of the floating unit 1, i.e., on the upper side in Fig. 3 etc., forms an accommodation space SS (shown in Fig. 8) inside, accommodates the vertically movable block 400 and a part of the horizontally movable block 700 in the accommodation space SS, and is a block formed by combining a plurality of members. The fixed block 100 has a bottom surface 110p which becomes the bottom surface of the floating unit 1, and the bottom surface 110p (a surface parallel to the paper surface in Fig. 1, the upper surface of the floating unit 1 in Fig. 3 etc.) is a surface which is connected to the robot hand via a flange when the floating unit 1 is used. The axis of the fixed block 100 is referred to as axis AX1.

[0024] As shown in Figure 3 etc., the fixed block 100 has a lock cylinder 120, a piston guide 140, a main body 160, a rotation restriction pin 180 (shown in Figure 7), a ball contact plate (upper) 200, a ball contact plate (lower) 220, a ball 240, a ball retainer (upper) 260, a ball retainer (lower) 280, a accommodating piston rotation stop pin 300 (shown in Figures 5 and 6), a accommodating piston support spring member 320, a magnet 340 (shown in Figures 5 and 6), and a fixed block fixing bolt 360 (shown in Figures 3 and 4).

[0025] As shown in Fig. 3 etc. and Figs. 9 to 13, the lock cylinder 120 is a substantially bottomed cylindrical member that is closed at the top and open at the bottom. The lock cylinder 120 has a bottom surface 110p (the upper surface of the floating unit 1 in this embodiment) for connecting the floating unit 1 to a robot hand. The lock cylinder 120 is disposed on the uppermost side of the floating unit 1 and connects to the robot hand to support the entire floating unit 1. At the same time, the lock cylinder 120 forms the outer shape of the upper side of the fixed block 100. As shown in Figs. 9 to 13, the lock cylinder 120 has a tubular portion 122 and an enlarged diameter portion 124.

[0026] The cylindrical portion 122 is formed in a substantially bottomed cylindrical shape. The inner peripheral surface of the cylindrical portion 122 is composed of a large diameter inner peripheral surface 122i1 and a small diameter inner peripheral surface 122i2 located above the large diameter inner peripheral surface 122i1 and having a smaller diameter than the large diameter inner peripheral surface 122i1. The space inside the large diameter inner peripheral surface 122i1 and the small diameter inner peripheral surface 122i2 forms a part of the storage space SS (shown in FIG. 8). The large diameter inner peripheral surface 122i1 and the small diameter inner peripheral surface 122i2 are formed smoothly so as to be slidable with the storage piston 420 described later. That is, the diameter of the large diameter inner peripheral surface 122i1 is set to be equal to the outer diameter of the flange portion 430 (shown in FIG. 28) of the storage piston 420. The diameter of the small diameter inner circumferential surface 122i2 is set to be equal to the outer diameter of the small diameter cylindrical portion 422 (shown in FIG. 28) of the accommodating piston 420. In addition, the height (length in the vertical direction) of the small diameter inner circumferential surface 122i2 coincides with the height of the small diameter cylindrical portion 422 of the accommodating piston 420.

[0027] The expanded diameter portion 124 is a portion that expands in diameter outward from a lower portion of the outer circumferential surface 122u of the cylindrical portion 122. As shown in Figs. 9 and 10, the expanded diameter portion 124 is formed in a substantially rectangular shape with rounded corners when viewed from above, and has four rounded corners 124j.

[0028] 9, 10, and 11, a bolt hole 126 penetrating in the up-down direction is formed in each of the four rounded corners 124j of the enlarged diameter portion 124. The bolt hole 126 is a through hole through which a fixing block fixing bolt 360 (shown in FIGS. 3 and 4) is inserted.

[0029] As shown in FIGS. 9, 10 and 13, the cylindrical portion 122 has four bolt holes 125, two holes 127, two holes 128, and a hole 129 formed therein.

[0030] As shown in Fig. 9 and Fig. 11, the four bolt holes 125 are formed between the small-diameter inner peripheral surface 122i2 and the outer peripheral surface 122u of the cylindrical portion 122 by drilling downward from the upper surface (bottom surface 110p). The four bolt holes 125 are formed spaced apart from one another by 90 degrees in the circumferential direction. The four bolt holes 125 are blind holes into which bolts (not shown) are screwed for connecting the floating unit 1 to a robot hand via a flange. The bolt holes 125 are formed with female screw threads.

[0031] As shown in Figures 10 and 12, the two holes 127 are formed by drilling upward in the peripheral wall between the small diameter inner peripheral surface 122i2 and the large diameter inner peripheral surface 122i1 of the cylindrical portion 122. The two holes 127 are blind holes for receiving and fixing the piston rotation restricting pin 300 (shown in Figures 5 and 6). The inner diameter of the hole 127 is set to be equal to the outer diameter of the piston rotation restricting pin 300. The two holes 127 are formed 180 degrees apart from each other in the circumferential direction.

[0032] 9 and 13, there are two holes 128 drilled downward on the upper surface of the cylindrical portion 122, i.e., the bottom surface 110p. The holes 128 are blind holes for improving the accuracy of alignment when performing an operation of attaching the floating unit 1 to the tip of a robot hand while aligning it. In other words, the holes 128 are blind holes for alignment with the robot hand. The two holes 128 are formed 180 degrees apart from each other in the circumferential direction.

[0033] 13, a hole 129 is formed in the cylindrical portion 122, penetrating between the small-diameter inner circumferential surface 122i2 and the outer circumferential surface 122u. The hole 129 is a through-hole for passing a wiring (power supply line) 442 (shown in FIG. 7) of a permanent electromagnetic holder 440 described later to the outside of the floating unit 1.

[0034] The piston guide 140 is a substantially annular member as shown in Figures 14 to 16. The piston guide 140 is disposed below the lock cylinder 120 as shown in Figure 3 etc. The piston guide 140 is formed so that the outer shape when viewed from above matches the outer shape of the enlarged diameter portion 124 of the lock cylinder 120 when viewed from above.

[0035] The piston guide 140 has an inner peripheral surface 142i. The inner peripheral surface 142i is formed smoothly so as to be slidable over a later-described housed piston 420 (shown in FIG. 3 and the like and FIG. 28). That is, the diameter of the inner peripheral surface 142i is set to be equal to the outer diameter of the large diameter cylindrical portion 426 of the housed piston 420. The space inside the inner peripheral surface 142i of the piston guide 140 forms a part of the housing space SS (shown in FIG. 8).

[0036] As shown in FIG. 14, the piston guide 140 has four bolt holes 143 and ten holes 144 formed therein.

[0037] As shown in Figures 14 and 15, the four bolt holes 143 are formed in portions that form rounded corners of the piston guide 140 when viewed from above. The bolt holes 143 are through holes through which fixed block fixing bolts 360 (shown in Figures 3 and 4) are inserted. The four bolt holes 143 are formed at positions corresponding to the positions of the four bolt holes 126 (shown in Figures 9 and 10) of the lock cylinder 120.

[0038] As shown in Figures 14 and 16, the ten holes 144 are formed by drilling downward from the upper surface slightly outside the inner peripheral surface 142i of the piston guide 140. The holes 144 are non-through holes that accommodate and support the accommodated piston support spring members 320 (shown in Figure 3, etc.) described later. The ten holes 144 are formed to be aligned at equal intervals in the circumferential direction.

[0039] 17 to 21, the main body 160 is a substantially bottomed cylindrical member with a partially open lower side. The main body 160 is disposed below the piston guide 140 as shown in Fig. 3 etc. The main body 160 is formed so that the outer shape when viewed from above matches the outer shape of the piston guide 140 when viewed from above. The main body 160 has a substantially cylindrical tubular portion 162 and a bottom plate portion 164 disposed below the tubular portion 162 and extending inward beyond the outer shape of the tubular portion 162.

[0040] As shown in Figs. 19 to 21, the cylindrical portion 162 has an inner peripheral surface 162i. The inner peripheral surface 162i has a female screw portion 162im on whose upper portion a female screw thread is formed. An outer peripheral surface 202 (described later, shown in Fig. 23) of a ball contact plate (upper) 200 is screwed into the female screw portion 162im. The inner diameter of the female screw portion 162im is set to be equal to the diameter of the outer peripheral surface 202 of the ball contact plate (upper) 200. The inner diameter of the inner peripheral surface 162i is set to be equal to the outer diameter of the ball contact plate (lower) 220 (shown in Fig. 24). A space formed inward by a part of the inner peripheral surface 162i forms a part of the accommodation space SS (shown in Fig. 8).

[0041] As shown in Figures 17 and 19, four bolt holes 166 are formed at 90 degrees apart from one another in the circumferential direction in a portion that forms a rounded corner of the peripheral wall of the cylindrical portion 162. The four bolt holes 166 are formed at positions corresponding to the positions of the four bolt holes 143 (shown in Figure 14) of the piston guide 140. The bolt holes 166 are blind holes formed by drilling downward from the upper surface of the peripheral wall of the cylindrical portion 162, and are formed with female screw threads. The bolt holes 166 are holes that can be screwed into the tip ends of the fixing block fixing bolts 360 (shown in Figures 3 and 4).

[0042] As shown in FIGS. 17 and 18, the bottom plate portion 164 is formed with a circular opening 165, four holes 167, and four holes 168.

[0043] 17 to 21, a circular opening 165 is formed in the bottom plate portion 164. The opening 165 is a portion into which a main body portion 842 (shown in FIG. 45) of a top plate 840, which will be described later, fits. The inner diameter of the opening 165 is set to be larger than the outer diameter of the main body portion 842 of the top plate 840. The length corresponding to this difference in diameter corresponds to the horizontal movable range of the top plate 840 (horizontally movable block 700). The space formed inside by the opening 165 forms part of the storage space SS (shown in FIG. 8).

[0044] As shown in Figures 17, 18 and 21, the four holes 167 are formed to penetrate the bottom plate portion 164 in the up-down direction. The four holes 167 are formed spaced 90 degrees apart from one another in the circumferential direction. The holes 167 are holes for receiving and fixing the rotation restriction pin 180 (shown in Figures 7 and 22). The holes 167 are composed of a large diameter hole 167d and a small diameter hole 167s disposed below the large diameter hole 167d.

[0045] The four holes 168 are blind holes formed by drilling from the lower surface upward in the bottom plate portion 164, as shown in Figures 17, 18, and 20. The four holes 168 are formed spaced apart from one another at 90 degrees in the circumferential direction. Hole 168 is adjacent to hole 167 in the circumferential direction, and adjacent holes 168 and 167 are spaced apart from one another at 45 degrees in the circumferential direction. Hole 168 is a hole for accommodating and fixing magnet 340 (shown in Figures 5 and 6), which will be described later.

[0046] As shown in FIG. 7, the rotation restriction pin 180 has its tip inserted into a rotation restriction pin hole 852 (shown in FIG. 46) of the top plate 840 described later, allowing movement of the top plate 840 in the θ direction within the range of the size of the rotation restriction pin hole 852 and restricting further rotation in the θ direction. The rotation restriction pin 180 is inserted downward into a hole 167 (shown in FIG. 21) of the main body 160 and fixed. As shown in FIG. 22, the rotation restriction pin 180 has a large diameter portion 182 and a small diameter portion 184 having a diameter smaller than that of the large diameter portion 182. The large diameter portion 182 fits into a large diameter hole 167d of the hole 167 of the main body 160. The small diameter portion 184 fits into a small diameter hole 167s of the hole 167. The tip of the small diameter portion 184 protrudes downward from the small diameter hole 167s and is inserted into the rotation restriction pin hole 852 of the top plate 840.

[0047] As shown in FIG. 3 and other figures, the ball contact plate (upper) 200 is disposed so as to fit into an upper portion of the inner peripheral surface 162i (shown in FIG. 19) of the main body 160, and supports the balls 240 held in a ball retainer (upper) 260 (described later) from above so as to be able to roll. The ball contact plate (upper) 200 is an annular member as shown in FIGS. 23(a) and (b). A male screw thread is formed on the outer peripheral surface 202 of the ball contact plate (upper) 200. This allows the ball contact plate (upper) 200 to be screwed into the female screw portion 162im of the inner peripheral surface 162i of the main body 160.

[0048] Two holes 206 are drilled downward on the upper surface 204 of the ball contact plate (upper) 200. The two holes 206 are holes into which a tool is inserted when the ball contact plate (upper) is rotated to screw into the female screw portion 162im of the main body 160. The two holes 206 are formed 180 degrees apart in the circumferential direction so as to face each other. The holes 206 are non-through holes.

[0049] The space inside the inner circumferential surface 201 of the ball contact plate (upper) 200 forms a part of the accommodation space SS (shown in FIG. 8).

[0050] As shown in Fig. 3 etc., the ball contact plate (lower) 220 is disposed so as to fit into a lower portion of the inner circumferential surface 162i (shown in Fig. 19) of the main body 160, and supports, from below, the balls 240 held in a ball retainer (lower) 280 (described below) so as to be able to roll. The ball contact plate (lower) 220 is an annular member, although not shown in Fig. 24. The space inside the inner circumferential surface 221 of the ball contact plate (lower) 220 forms part of the accommodation space SS (shown in Fig. 8).

[0051] As shown in Figure 3 etc., the ball retainer (top) 260 is disposed between the ball retaining plate (top) 200 and the ball retaining plate (middle) 720 (described later) of the horizontally movable block 700, and holds the ball 240 in a rollable manner, thereby enabling the ball retaining plate (middle) 720 to slide horizontally or in the θ direction, or in both directions.

[0052] The ball retainer (upper) 260 is an annular member as shown in Figs. 25(a) and (b). The ball retainer (upper) 260 has a plurality of ball retaining holes 262 formed therein so as to be arranged at equal intervals in the circumferential direction. The balls 240 are rotatably retained in the ball retaining holes 262. The thickness of the ball retainer (upper) 260 in the vertical direction is smaller than the diameter of the balls 240. As a result, the upper and lower parts of the balls 240 are exposed from the upper and lower surfaces of the ball retainer (upper) 260. The outer diameter of the ball retainer (upper) 260 is set smaller than the diameter of the inner peripheral surface 162i of the main body 160. As a result, the ball retainer (upper) 260 is slidable inward from the inner peripheral surface 162i of the main body 160 in the horizontal direction, the θ direction, or both directions.

[0053] The space inside an inner circumferential surface 264 of the ball retainer (upper) 260 forms a part of the accommodation space SS (shown in FIG. 8).

[0054] As shown in Fig. 3 etc., the ball retainer (lower) 280 is disposed between the ball retaining plate (lower) 220 and the ball retaining plate (middle) 720 of the horizontally movable block 700, and holds the balls 240 rotatably, thereby enabling the ball retaining plate (middle) 720 to slide in the horizontal direction or the θ direction, or in both directions. The configuration of the ball retainer (lower) 280 is the same as the configuration of the ball retainer (upper) 260. The space inside the inner circumferential surface of the ball retainer (lower) 280 forms part of the accommodation space SS (shown in Fig. 8).

[0055] As shown in Figures 5 and 6, the accommodating piston rotation stop pin 300 is accommodated and fixed in the hole 127 (shown in Figure 12) of the lock cylinder 120, and is also accommodated in the hole 429 (shown in Figure 29) of the accommodating piston 420 (described later) of the upper and lower movable block 400 to prevent the accommodating piston 420 and the permanent electromagnetic holder 440 from rotating in the θ direction.

[0056] As shown in FIG. 3 and the like, the accommodating piston support spring member 320 is accommodated in the hole 144 (shown in FIG. 16) of the piston guide 140 and supports the accommodating piston 420 of the vertically movable block 400 while biasing it upward. As described later, when the permanent electromagnetic holder 440 is in the adsorption ON state, the accommodating piston 420 moves downward together with the permanent electromagnetic holder 440. Even if the permanent electromagnetic holder 440 is in the adsorption OFF state, the accommodating piston 420 tries to remain positioned downward due to its own weight and the weight of the permanent electromagnetic holder 440. However, when the permanent electromagnetic holder 440 is in the adsorption OFF state, the horizontally movable block 700 does not become movable unless the permanent electromagnetic holder 440 is separated from the adsorption plate 740, so it is necessary to move the accommodating piston 420 that accommodates and holds the permanent electromagnetic holder 440 upward. At this time, the accommodating piston support spring member 320 moves the accommodating piston 420 that accommodates and holds the permanent electromagnetic holder 440 upward. Therefore, the elastic force of the accommodating piston support spring member 320 is set to be smaller than the adhesive force of the permanent electromagnetic holder 440 in the adsorption ON state, and is set to be larger than the adhesive force caused by gravity due to the weights of the accommodating piston 420 and the permanent electromagnetic holder 440 plus the residual magnetic force of the permanent electromagnetic holder 440 in the adsorption OFF state.

[0057] 5 and 6, the magnet 340 is accommodated in and fixed to a hole 168 (shown in FIG. 20) of the main body 160. The magnet 340 attracts a magnet 880 (shown in FIGS. 5 and 6) accommodated in and fixed to a magnet hole 854 (shown in FIG. 45) of a top plate 840 of a horizontally movable block 700 (described later), thereby correcting positional deviation of the top plate 840 in the horizontal direction or the θ direction, or in both directions.

[0058] As shown in Figures 3 and 4, the fixed block fixing bolt 360 is inserted through the bolt hole 126 (shown in Figure 11) of the lock cylinder 120, the bolt hole 143 (shown in Figure 15) of the piston guide 140, and the bolt hole 166 (shown in Figure 19) of the main body 160, thereby fixing the lock cylinder 120, the piston guide 140 and the main body 160 together.

[0059] (Up and down movable block) As shown in Figure 3 etc., the vertically movable block 400 is accommodated in the upper part of the storage space SS (shown in Figure 8) formed by the fixed block 100 of the floating unit 1, and is configured so as to be able to slide vertically within the storage space SS, and is a block formed by combining multiple components.

[0060] As shown in Figure 3 etc., the upper and lower movable block 400 has a accommodating piston 420, a permanent electromagnetic holder 440, a permanent electromagnetic holder holding bolt 460 (shown in Figures 5 and 6), a center guide 480 (shown in Figures 3 and 4), and an auxiliary pin guide 500 (shown in Figures 5 and 6).

[0061] The accommodating piston 420 is a generally cylindrical member with a top that is closed and a bottom that is open, as shown in Fig. 3 and other figures and Fig. 26 to Fig. 30. The accommodating piston 420 is a member for accommodating and holding the permanent electromagnetic holder 440 in a state in which the adsorption surface 441 of the permanent electromagnetic holder 440 is exposed downward (the opposite side to the bottom surface 110p) and for allowing the permanent electromagnetic holder 440 to move in the vertical direction, as shown in Fig. 3 and other figures. The accommodating piston 420 has a small diameter cylindrical portion 422, a large diameter cylindrical portion 426 disposed below the small diameter cylindrical portion 422, and a flange portion 430 extending outward from the large diameter cylindrical portion 426.

[0062] As shown in FIGS. 26 to 30, the small diameter cylinder portion 422 is formed in a generally cylindrical shape with a top, and has an inner circumferential surface 422i, an outer circumferential surface 422u, and a ceiling portion 424 disposed on the upper side.

[0063] The inner circumferential surface 422i forms a space therein for accommodating and holding the permanent electromagnetic holder 440. Therefore, the diameter of the inner circumferential surface 422i is set to be equal to the outer diameter of the permanent electromagnetic holder 440.

[0064] The outer peripheral surface 422u is formed smoothly so as to come into contact with the small-diameter inner peripheral surface 122i2 (shown in FIG. 11) of the lock cylinder 120 and to be slidable relative to the small-diameter inner peripheral surface 122i2. This allows the containing piston 420 to slide vertically relative to the lock cylinder 120.

[0065] 30, a hole 423 penetrating between an inner circumferential surface 422i and an outer circumferential surface 422u is formed in the small diameter cylindrical portion 422. The hole 423 is a hole for passing a wiring (power supply line) 442 (shown in FIG. 7) of the permanent electromagnetic holder 440 to the outside of the floating unit 1.

[0066] 26, 27, and 29, a bolt hole 425 is formed in the ceiling portion 424. The bolt hole 425 is composed of a large diameter hole 425d and a small diameter hole 425s disposed below the large diameter hole 425d.

[0067] As shown in FIGS. 27 to 30, the large diameter cylindrical portion 426 is formed in a generally cylindrical shape having an outer diameter larger than the outer diameter of the small diameter cylindrical portion 422, and has an inner peripheral surface 426i and an outer peripheral surface 426u.

[0068] The inner circumferential surface 426i is formed continuously in the up-down direction on the inner circumferential surface 422i of the small diameter cylindrical portion 422, and the inner circumferential surface 422i and the inner circumferential surface 426i form a cylindrical space therein. The permanent electromagnetic holder 440 is accommodated and held in this space. Therefore, the diameter of the inner circumferential surface 426i is set to be equal to the outer diameter of the permanent electromagnetic holder 440. The height (length in the up-down direction) of the inner circumferential surface 422i and the inner circumferential surface 426i is set to be equal to the height of the permanent electromagnetic holder 440.

[0069] The outer circumferential surface 426u is configured to be able to slide up and down in contact with the inner circumferential surface 142i (shown in FIG. 15) of the piston guide 140. In other words, the outer circumferential surface 426u is formed smoothly.

[0070] As shown in FIGS. 27 to 29, the large diameter cylindrical portion 426 has four holes 427, two holes 428, and two holes 429 formed therein.

[0071] As shown in Figs. 26, 27 and 28, the four holes 427 are formed in the large diameter cylindrical portion 426 between the inner peripheral surface 426i and the outer peripheral surface 426u by drilling from the lower surface upward. The four holes 427 are non-through holes formed at 90 degrees intervals from each other in the circumferential direction. The holes 427 accommodate and fix the center guide 480. Therefore, the inner diameter of the hole 427 is set to be equal to the outer diameter of the center guide 480. The depth (vertical length) of the hole 427 is set to be approximately equal to the height (vertical length) of the center guide 480.

[0072] As shown in Figs. 27 and 29, the two holes 428 are formed in the large diameter cylindrical portion 426 between the inner peripheral surface 426i and the outer peripheral surface 426u by drilling from the lower surface upward. The two holes 428 are non-through holes formed 180 degrees apart from each other in the circumferential direction. The hole 428 accommodates and holds the auxiliary pin guide 500 (shown in Figs. 5, 6 and 32). Therefore, the inner diameter of the hole 428 is set to be equal to the outer diameter of the auxiliary pin guide 500. The depth (vertical length) of the hole 428 is set to be approximately equal to the height (vertical length) of the auxiliary pin guide 500.

[0073] As shown in Figs. 26 and 29, the two holes 429 are formed in the large diameter cylindrical portion 426 between the inner peripheral surface 426i and the outer peripheral surface 426u by drilling from the upper surface downward. The two holes 429 are non-through holes formed 180 degrees apart from each other in the circumferential direction. The hole 429 is a hole into which the piston rotation stopping pin 300 shown in Figs. 5 and 6 is inserted. The hole 429 is formed at a position corresponding to the position of the hole 127 (shown in Fig. 12) of the lock cylinder 120. The hole 429 is configured to allow the piston rotation stopping pin 300 to move up and down relative to the piston 420 as the piston 420 moves up and down. That is, the surface forming the hole 429 is formed smoothly, and the inner diameter of the hole 429 is set to be approximately equal to the outer diameter of the piston rotation stopping pin 300.

[0074] 28 to 30, the flange portion 430 is formed to extend outward from an upper portion of the large-diameter cylindrical portion 426. An outer peripheral surface 430u of the flange portion 430 is configured to be in contact with the large-diameter inner peripheral surface 122i1 (shown in FIG. 11) of the lock cylinder 120 and to be slidable in the up-down direction. In other words, the outer peripheral surface 430u is formed smoothly.

[0075] The permanent electromagnetic holder 440 is a permanent electromagnetic holder described in Patent Document 1. Specifically, the permanent electromagnetic holder 440 has an adsorption surface 441 (illustrated in FIG. 3 to FIG. 6) that is adsorbed to an object to be attracted (in this embodiment, an adsorption plate 740), and is configured to be able to attract the object to be attracted in an adsorption ON state, and is configured to be able to detach the attracted object to be attracted in an adsorption OFF state. The permanent electromagnetic holder 440 includes a first magnet, a second magnet, and a coil, which are not shown. The adsorption ON / OFF state of the permanent electromagnetic holder 440 is switched by momentarily energizing the coil when switching the adsorption ON / OFF state, thereby switching the magnetization direction of the first magnet. Once the permanent electromagnetic holder 440 is in the adsorption ON state, it maintains the adsorption ON state until it is momentarily energized again. Similarly, once the permanent electromagnetic holder 440 is in the adsorption OFF state, it maintains the adsorption OFF state until it is momentarily energized again. 7, the permanent magnet holder 440 further includes a wiring (power line) 442. The coil is energized through the wiring (power line) 442. The residual magnetic force of the permanent magnet holder 440 in the attraction OFF state is 1% or less of the magnetic force of the permanent magnet holder 440 in the attraction ON state. The permanent magnet holder 440 can be operated by power from, for example, a 24-volt mobile battery.

[0076] 5 and 6, the permanent electromagnetic holder holding bolt 460 is inserted through a bolt hole 425 (shown in FIG. 29) in the ceiling portion 424 of the accommodating piston 420 and screwed into a bolt hole (not shown) formed in the upper surface of the permanent electromagnetic holder 440 to hold the permanent electromagnetic holder 440 in a state accommodated in the accommodating piston 420. The head of the permanent electromagnetic holder holding bolt 460 fits into the large diameter hole 425d of the bolt hole 425, and the shaft of the permanent electromagnetic holder holding bolt 460 is inserted through the small diameter hole 425s of the bolt hole 425.

[0077] 3 and 4, the center guide 480 faces a center pin 780 (described later) of the horizontally movable block 700 in the vertical direction, and comes into contact with the center pin 780 when the vertically movable block 400 is attracted to the horizontally movable block 700, thereby correcting a positional deviation in the horizontal direction or the θ direction, or both directions, of an axis AX2 (described later) of the horizontally movable block 700 relative to an axis AX1 of the fixed block 100. The center guide 480 is a substantially columnar member as shown in FIG. 31, and has a recess 482 formed in a tapered shape whose diameter increases downward. Four center guides 480 are provided on the vertically movable block 400, and are accommodated and held in four holes 427 (shown in FIG. 28) of the accommodation piston 420, respectively.

[0078] As shown in Figs. 5 and 6, the auxiliary pin guide 500 faces an auxiliary pin 800 (described later) of the horizontally movable block 700 in the vertical direction, and holds the horizontally movable block 700 so as to fit into the tip of the auxiliary pin 800 and stop the horizontally movable block 700 from sliding in the horizontal direction, the θ direction, or both directions when the vertically movable block 400 is attracted to the horizontally movable block 700. As shown in Fig. 32, the auxiliary pin guide 500 is a substantially columnar member, and has a recess 502 that opens downward. The recess 502 is a recess into which the tip of the auxiliary pin 800 can fit. Two auxiliary pin guides 500 are provided on the vertically movable block 400, and are accommodated and held in two holes 428 (shown in Fig. 29) of the accommodation piston 420, respectively.

[0079] (Horizontal movable block) As shown in Fig. 3 etc., the horizontally movable block 700 is disposed below the vertically movable block 400, is accommodated in the lower portion of the accommodation space SS (shown in Fig. 8) formed by the fixed block 100, and is configured to be able to slide in the horizontal direction, the θ direction, or both directions within the accommodation space SS, and is a block configured by combining a plurality of members. The horizontally movable block 700 has a top surface 841p. The axis of the horizontally movable block 700 is referred to as axis AX2.

[0080] As shown in Figure 3 etc., the horizontally movable block 700 has a ball contact plate (middle) 720, an attraction plate 740, an attraction plate mounting bolt 760 (shown in Figure 7), a center pin 780 (shown in Figures 3 and 4), an auxiliary pin 800 (shown in Figures 5 and 6), an auxiliary pin support spring member 820 (shown in Figures 5 and 6), a top plate 840, a top plate mounting bolt 860 (shown in Figures 5 to 7), and a magnet 880 (shown in Figures 5 and 6).

[0081] As shown in Fig. 3 etc., the ball contact plate (middle) 720 is disposed between the ball retainer (upper) 260 and the ball retainer (lower) 280, and is supported by the balls 240 held by the ball retainer (upper) 260 and the balls 240 held by the ball retainer (lower) 280, i.e., a part of the fixed block 100, so as to be slidable in the horizontal direction or the θ direction, or in both directions. As a result, the ball contact plate (middle) 720 supports the entire horizontally movable block 700 so as to be slidable in the horizontal direction or the θ direction, or in both directions. As shown in Figs. 33 to 36, the ball contact plate (middle) 720 has a substantially disc-shaped main body 722 and a flange 730 extending outward from a lower part of the main body 722.

[0082] 3 and other drawings, the main body portion 722 is disposed inwardly of the ball retainer (upper) 260. As a result, the outer diameter of the main body portion 722 is set to be smaller than the diameter of the inner circumferential surface 264 (shown in FIG. 25) of the ball retainer (upper) 260.

[0083] 33 to 36, main body portion 722 is formed with four bolt holes 723, four center pin holes 724, two auxiliary pin holes 725, and two bolt holes 726. Furthermore, main body portion 722 has a large diameter recess 727 formed by drilling from the lower surface upward.

[0084] Each of the four bolt holes 723 is a hole that passes through the main body 722 in the up-down direction, and is a hole for inserting a top plate mounting bolt 860. The four bolt holes 723 are formed at 90 degrees intervals from one another in the circumferential direction, as shown in FIG.

[0085] Each of the four center pin holes 724 is a hole that penetrates the main body portion 722 in the vertical direction and is a hole for accommodating and holding a large diameter portion 782 (shown in FIG. 41) described later of the center pin 780. As shown in FIG. 33, the four center pin holes 724 are formed circumferentially spaced apart from one another by 90 degrees, and are formed outward of the four bolt holes 723.

[0086] Each of the two auxiliary pin holes 725 is a hole that penetrates the main body portion 722 in the vertical direction and receives a large diameter cylindrical portion 802 (shown in FIG. 42) of the auxiliary pin 800, which will be described later, so as to be slidable in the vertical direction. The two auxiliary pin holes 725 are formed 180 degrees apart from each other in the circumferential direction, as shown in FIG. 33, and are formed outside the four bolt holes 723.

[0087] Each of the two bolt holes 726 is a hole that passes through the main body 722 in the up-down direction, and is a hole into which the shaft of the suction plate mounting bolt 760 is screwed. That is, a female screw thread is formed in the bolt hole 726. The two bolt holes 726 are formed 180 degrees apart from each other in the circumferential direction, as shown in Fig. 33, and are formed outside the four bolt holes 723.

[0088] The large diameter recess 727 is a recess into which the tip of a main body 842 (shown in FIG. 45) of the top plate 840 fits. The inner diameter of the large diameter recess 727 is set to be equal to the outer diameter of the main body 842 of the top plate 840.

[0089] The flange portion 730 is sandwiched between the ball 240 held by the ball retainer (upper) 260 and the ball 240 held by the ball retainer (lower) 280, and is supported slidably. The outer diameter of the flange portion 730 is set to be smaller than the outer diameter of the ball retainer (upper) 260 and the outer diameter of the ball retainer (lower) 280, and is set to be larger than the inner diameter (diameter of the inner circumferential surface 264) of the ball retainer (upper) 260 and the inner diameter of the ball retainer (lower) 280.

[0090] As shown in FIG. 3 and other figures, the attraction plate 740 is placed on the upper surface (surface facing the bottom surface) of the main body 722 of the ball retainer (middle) 720, and is integrally connected to the ball retainer (middle) 720 by an attraction plate mounting bolt 760 (shown in FIG. 7). The attraction plate 740 is made of a magnetic material that can be attracted to the permanent electromagnetic holder 440, such as SS400 steel. That is, at least a part of the vertically movable block 400 is made of a magnetic material. The outer diameter of the attraction plate 740 is set to be equal to the outer diameter of the main body 722 of the ball contact plate (middle) 720.

[0091] As shown in Figures 37 to 40, the attraction plate 740 is formed with four bolt holes 743, four center pin holes 744, two auxiliary pin holes 745, and two bolt holes 746.

[0092] Each of the four bolt holes 743 is a hole that passes through the attraction plate 740 in the vertical direction, and is a hole into which a top plate mounting bolt 860 is screwed. A female screw thread is formed in each of the four bolt holes 743. As shown in FIG. 37 , the four bolt holes 743 are formed at intervals of 90 degrees from one another in the circumferential direction, and are formed at positions corresponding to the positions of the four bolt holes 723 of the ball contact plate (middle) 720.

[0093] Each of the four center pin holes 744 is a hole that penetrates the suction plate 740 in the vertical direction and is a hole for accommodating and holding a small diameter portion 784 (shown in FIG. 41 ) described later of the center pin 780. As shown in FIGS. 37 and 38 , the four center pin holes 744 are formed 90 degrees apart from one another in the circumferential direction, are formed outside the four bolt holes 743, and are formed at positions corresponding to the positions of the four center pin holes 724 of the ball contact plate (middle) 720.

[0094] Each of the two auxiliary pin holes 745 is a hole that penetrates the suction plate 740 in the vertical direction and receives an upper portion of a large diameter cylinder portion 802 (shown in FIG. 42) of the auxiliary pin 800 and a small diameter column portion 804, which will be described later, so as to be slidable in the vertical direction. As shown in FIG. 39, the auxiliary pin hole 745 is composed of a large diameter hole 745d and a small diameter hole 745s disposed above the large diameter hole 745d. As shown in FIG. 37, the two auxiliary pin holes 745 are formed 180 degrees apart from each other in the circumferential direction, are formed outside the four bolt holes 743, and are formed at positions corresponding to the positions of the two auxiliary pin holes 725 of the ball contact plate (middle) 720.

[0095] The large diameter hole 745d of the auxiliary pin hole 745 receives a large diameter cylinder portion 802 (described later) of the auxiliary pin 800 so as to be slidable in the vertical direction. The small diameter hole 745s receives a small diameter column portion 804 (described later) of the auxiliary pin 800 so as to be slidable in the vertical direction. The inner diameter of the large diameter hole 745d is set to be equal to the outer diameter of the large diameter cylinder portion 802 of the auxiliary pin 800. The inner diameter of the small diameter hole 745s is set to be equal to the outer diameter of the small diameter column portion 804 of the auxiliary pin 800. The inner surfaces of the large diameter hole 745d and the small diameter hole 745s are formed smoothly.

[0096] Each of the two bolt holes 746 is a hole that penetrates the suction plate 740 in the vertical direction, and is a hole through which the head and shaft of the suction plate mounting bolt 760 (shown in FIG. 7) is inserted. As shown in FIG. 40, the bolt hole 746 is composed of a large diameter hole 746d and a small diameter hole 746s disposed below the large diameter hole 746d. The large diameter hole 746d is a hole through which the head of the suction plate mounting bolt 760 is inserted. The small diameter hole 746s is a hole through which the shaft of the suction plate mounting bolt 760 is inserted. As shown in FIG. 37, the two bolt holes 746 are formed 180 degrees apart from each other in the circumferential direction, are formed outside the four bolt holes 743, and are formed at positions corresponding to the positions of the two bolt holes 726 of the ball contact plate (middle) 720.

[0097] 7, the suction plate mounting bolt 760 is inserted downward through the bolt hole 746 (shown in FIG. 40) of the suction plate 740 placed on the ball contact plate (middle) 720 and the bolt hole 726 (shown in FIG. 34) of the ball contact plate (middle) 720, thereby integrally connecting the suction plate 740 to the ball contact plate (middle) 720. The shaft of the suction plate mounting bolt 760 is screwed into the bolt hole 726 of the ball contact plate (middle) 720.

[0098] 3 and 4, the center pin 780 is inserted upward and fitted into the center pin hole 724 (shown in FIG. 34) of the ball contact plate (middle) 720 to which the suction plate 740 is integrally connected, and the center pin hole 744 (shown in FIG. 38) of the suction plate 740. A tip portion 786 of the center pin 780 protrudes upward from the suction plate 740. The center pin 780 has a large diameter portion 782, a small diameter portion 784 disposed above the large diameter portion 782, and a tip portion 786 disposed above the small diameter portion 784, as shown in FIG.

[0099] The vertical length of the large diameter portion 782 is set to be equal to the thickness of the main body portion 722 of the ball contact plate (middle) 720. The vertical length of the small diameter portion 784 is set to be greater than the thickness of the suction plate 740. The tip portion 786 is formed in a semispherical shape. The tip portion 786 protruding upward from the suction plate 740 contacts the tapered recessed portion 502 of the center guide 480 of the vertical movable block 400, and can be guided to the horizontal center position of the recessed portion 502. The position of the center pin 780 is set so that when the horizontal center position of the tip portion 786 of the center pin 780 and the horizontal center position of the recessed portion 502 of the center guide 480 overlap, the axis AX2 of the horizontally movable block 700 and the axis AX1 of the fixed block 100 overlap.

[0100] 5 and 6, the auxiliary pin 800 is inserted upward through the auxiliary pin hole 725 (shown in FIG. 35) of the ball contact plate (middle) 720 to which the suction plate 740 is integrally connected, and the auxiliary pin hole 745 (shown in FIG. 39) of the suction plate 740, and is fitted so as to be slidable in the up-down direction. The tip of the auxiliary pin 800 protrudes upward from the suction plate 740. The auxiliary pin 800 has a large diameter cylindrical portion 802 and a small diameter pillar portion 804 disposed above the large diameter cylindrical portion 802, as shown in FIG.

[0101] The large diameter cylindrical portion 802 is formed in a cylindrical shape with a top that is open at the bottom and closed at the top. The large diameter cylindrical portion 802 has a recess 803 that is open downward. The recess 803 houses the auxiliary pin support spring member 820, and receives the upward biasing force of the auxiliary pin support spring member 820 at the ceiling of the recess 803. The vertical length of the large diameter cylindrical portion 802 is set to be equal to or slightly smaller than the thickness of the ball contact plate (middle) 720.

[0102] As shown in Fig. 42, the small diameter pillar portion 804 is a portion that extends upward in a pillar shape from the ceiling portion of the large diameter cylinder portion 802. The vertical length of the small diameter pillar portion 804 is set to be longer than the vertical length of the small diameter hole 745s (shown in Fig. 39) of the auxiliary pin hole 745 of the attraction plate 740. As a result, when the auxiliary pin 800 is located upward by the biasing force of the auxiliary pin support spring member 820, the tip portion of the small diameter pillar portion 804 is in a form that protrudes upward from the upper surface of the attraction plate 740.

[0103] 5 and 6, the auxiliary pin support spring member 820 is housed in a recess 803 (shown in FIG. 42) of the large diameter cylindrical portion 802 of the auxiliary pin 800, and is also housed in an auxiliary pin hole 725 (shown in FIG. 35) of the main body portion 722 of the ball contact plate (middle) 720 to urge and support the auxiliary pin 800 upward. An upper end of the auxiliary pin support spring member 820 abuts against a ceiling portion of the recess 803 of the large diameter cylindrical portion 802 of the auxiliary pin 800. A lower end of the auxiliary pin support spring member 820 abuts against an upper surface of a main body portion 842 (shown in FIG. 45) of the top plate 840, which will be described later.

[0104] 3 and other figures, the top plate 840 is disposed at the bottom of the floating unit 1 and is connected to a chuck that grips a workpiece. The top plate 840 has a top surface 841p (the lower surface of the floating unit 1 in this embodiment) for connection to the chuck.

[0105] As shown in FIGS. 43 to 47, the top plate 840 has a substantially cylindrical main body portion 842 and an expanded diameter portion 850 that expands in diameter outward from the lower portion of the main body portion 842.

[0106] As shown in Figs. 43, 44, and 45, four bolt holes 844 are formed in the main body 842. The bolt holes 844 are holes that penetrate the main body 842 in the up-down direction, and are holes through which the top plate mounting bolts 860 are inserted. As shown in Figs. 43 and 44, the four bolt holes 844 are formed at 90 degrees apart from each other in the circumferential direction, and are formed at positions corresponding to the positions of the four bolt holes 723 of the ball contact plate (middle) 720. As shown in Fig. 45, the bolt holes 844 are composed of a large diameter hole 844d and a small diameter hole 844s disposed above the large diameter hole 844d. The large diameter hole 844d is a hole through which the head of the top plate mounting bolt 860 is inserted, and the small diameter hole 844s is a hole through which the shaft of the top plate mounting bolt 860 is inserted.

[0107] The outer diameter of the expanded diameter portion 850 is set to be equal to the minimum diameter when viewed from below the main body 160 (shown in FIG. 2) of the fixed block 100. The expanded diameter portion 850 is formed in an annular shape, which differs from the shape of the main body 160. As shown in FIGS. 43, 45, and 46, the expanded diameter portion 850 is formed with four rotation restriction pin holes 852 and four magnet holes 854.

[0108] As shown in Fig. 43 and Fig. 46, the four rotation restriction pin holes 852 are non-through holes formed by drilling downward from the upper surface of the enlarged diameter portion 850, and are formed at 90 degrees apart from each other in the circumferential direction. As shown in Fig. 7, each of the four rotation restriction pin holes 852 is a hole that receives the small diameter portion 184 (shown in Fig. 22) of the rotation restriction pin 180 protruding downward from the main body 160, and defines the rotation range in the θ direction of the top plate 840 of the horizontally movable block 700 that is rotatable in the θ direction. In other words, the top plate 840 (horizontally movable block 700) is rotatable in the θ direction within a range in which the rotation restriction pin 180 does not come into contact with the circumferential surface that forms the rotation restriction pin holes 852.

[0109] 43 and 45, the four magnet holes 854 are blind holes formed by drilling downward from the upper surface of the enlarged diameter portion 850, and are formed spaced 90 degrees apart from one another in the circumferential direction. Each of the four magnet holes 854 is a hole that accommodates and holds a magnet 880 (shown in FIGS. 5 and 6).

[0110] As shown in FIGS. 43, 44, 46 and 47, two holes 856 and four screw holes 858 are formed at a position spanning the main body portion 842 and the enlarged diameter portion 850.

[0111] The two holes 856 are formed by drilling upward from the lower surface (top surface 841p) of the top plate 840. The two holes 856 are blind holes for improving the accuracy of alignment when performing an operation of attaching the chuck while aligning it to the top plate 840. In other words, the holes 856 are holes for alignment with the chuck. The two holes 856 are formed 180 degrees apart from each other in the circumferential direction.

[0112] The four screw holes 858 are formed so as to penetrate from the lower surface (top surface 841p) of the top plate 840 to the upper surface of the enlarged diameter portion 850. The screw holes 858 are holes into which bolts (not shown) are screwed to attach the chuck to the top plate 840. The four screw holes 858 are formed at 90° intervals from one another in the circumferential direction.

[0113] As shown in Figures 5 and 6, the top plate mounting bolt 860 is a bolt for attaching the top plate 840 to the ball contact plate (middle) 720 and the suction plate 740 by inserting it through the bolt hole 844 (shown in Figure 45) of the top plate 840 and the bolt hole 723 (shown in Figure 35) of the ball contact plate (middle) 720 and screwing it into the bolt hole 743 (shown in Figure 39) of the suction plate 740.

[0114] As shown in Figs. 5 and 6, the magnet 880 is accommodated and held in the magnet hole 854 (shown in Fig. 45) of the top plate 840. The magnet 880 is disposed at a position substantially opposite the magnet 340 of the fixed block 100. The magnets 880 and 340 act to attract each other. As a result, even if the horizontally movable block 700 (top plate 840) slides in the horizontal direction or the θ direction, or in both directions, it tends to return to its original position. In other words, even if the axis AX2 of the horizontally movable block 700 is misaligned with the axis AX1 of the fixed block 100, the horizontally movable block 700 in the movable state moves horizontally due to the action of the magnet 880 and the magnet 340 so that the axis AX1 and the axis AX2 overlap.

[0115] (Movement of the floating unit) Next, we will explain how the floating unit 1 connected between the robot hand and the chuck moves before and after the process of inserting or pressing (hereinafter referred to as "pressing") the workpiece held by the chuck into the target hole in accordance with the movement of the robot hand.

[0116] First, in a stage before press-fitting (for example, a stage in which the chuck grips the workpiece), the floating unit 1 functions as if the horizontally movable block 700 is in a restrained state.

[0117] That is, at this stage, the permanent electromagnetic holder 440 of the vertical movable block 400 is in the suction ON state, and the vertical movable block 400 (the permanent electromagnetic holder 440 housed in the housing piston 420) is adsorbed to the horizontally movable block 700 (the suction plate 740), thereby preventing the horizontally movable block 700 from sliding in the horizontal direction, the θ direction, or both.

[0118] In the next process, immediately before the press-fitting, a control device (not shown) of the system for operating the floating unit 1 instantaneously energizes the permanent electromagnetic holder 440 to switch the suction ON state of the permanent electromagnetic holder 440 to the suction OFF state. As a result, the urging force of the accommodation piston support spring member 320 separates the vertically movable block 400 (permanent electromagnetic holder 440) from the horizontally movable block 700 (suction plate 740), and the horizontally movable block 700 becomes slidable in the horizontal direction or the θ direction or in both directions (movable state).

[0119] In the next step, when the workpiece is pressed into the hole of the target part, the floating unit 1 functions to correct the misalignment between the central axis of the hole of the part and the central axis of the workpiece by sliding the horizontally movable block 700 of the floating unit 1 horizontally or in the θ direction, or in both directions, relative to the fixed block 100.

[0120] In the next step, after the workpiece has been pressed into the workpiece, the chuck releases the workpiece, and the floating unit 1 stops the movement of the horizontally movable block 700.

[0121] At this time, axis AX2 of horizontally movable block 700 is misaligned with axis AX1 of fixed block 100 (state in FIG. 3). Here, magnet 880 of horizontally movable block 700 and magnet 340 of fixed block 100 attract each other to correct the misalignment of axis AX2 with respect to axis AX1, but there are cases where the misalignment cannot be corrected sufficiently. However, even in such cases, floating unit 1 can correct the misalignment, and the movement of floating unit 1 will be further explained below.

[0122] When the permanent electromagnetic holder 440 is momentarily energized in the suction OFF state and the permanent electromagnetic holder 440 is put into the suction ON state, the vertically movable block 400 tries to be attracted to the horizontally movable block 700 .

[0123] As the vertically movable block 400 (permanent electromagnetic holder 440 housed in the housing piston 420) tries to be attracted to the horizontally movable block 700 (attraction plate 740), the vertically movable block 400 moves downward, and the center guide 480 of the vertically movable block 400 and the tip 786 of the center pin 780 of the horizontally movable block 700 approach each other. As they approach each other, the tip 786 of the center pin 780 is guided by the tapered shape of the recess 482 of the center guide 480, and the positional deviation of the axis AX2 of the horizontally movable block 700 relative to the axis AX1 of the fixed block 100 in the horizontal direction, the θ direction, or both is corrected.

[0124] In this manner, by the vertically movable block 400 being attracted to the horizontally movable block 700, the axis AX2 of the horizontally movable block 700 and the axis AX1 of the fixed block 100 are brought into overlapping relation (the state shown in FIG. 4), and the horizontally movable block 700 returns to the position it was in before it slid (hereinafter referred to as "the horizontally movable block 700 returning to the origin").

[0125] Then, the lower surface of the vertically movable block 400 (the attraction surface 441 of the permanent electromagnetic holder 440) comes into contact with the upper surface of the horizontally movable block 700, and the horizontally movable block 700 is stopped by frictional force.

[0126] Furthermore, in a state where the axis AX2 of the horizontally movable block 700 and the axis AX1 of the fixed block 100 overlap (the state in FIG. 5), when the vertically movable block 400 tries to adhere to the horizontally movable block 700, the auxiliary pin guide 500 of the vertically movable block 400 and the auxiliary pin 800 of the horizontally movable block 700 approach each other. As they approach each other, the tip of the small diameter column part 804 of the auxiliary pin 800 fits into the recess 502 of the auxiliary pin guide 500, and the horizontally movable block 700 is held by the vertically movable block 400 in the horizontal direction or the θ direction or both directions (the state in FIG. 6). That is, the fitting of the auxiliary pin 800 into the auxiliary pin guide 500 makes the restraining state of the horizontally movable block 700 more reliable.

[0127] Here, when the axis AX2 of the horizontally movable block 700 and the axis AX1 of the fixed block 100 do not overlap, i.e., when the horizontally movable block 700 is sliding, when the vertically movable block 400 (permanent electromagnetic holder 440) tries to adhere to the horizontally movable block 700 (attraction plate 740), it is thought that the auxiliary pin 800 protruding upward from the attraction plate 740 may interfere with the lower surface of the vertically movable block 400 (e.g., the attraction surface 441 of the permanent electromagnetic holder 440), hindering the return of the horizontally movable block 700 to the origin. However, the auxiliary pin 800 is not fixed in the horizontally movable block 700, but is supported by the auxiliary pin support spring member 820 while being biased upward, so that it is pushed downward by the lower surface of the vertically movable block 400 and does not protrude upward from the attraction plate 740. Therefore, even if the axis AX2 of the horizontally movable block 700 and the axis AX1 of the fixed block 100 do not overlap at the stage when the vertically movable block 400 is about to be attracted to the horizontally movable block 700, the auxiliary pin 800 does not hinder the horizontally movable block 700 from returning to the origin.

[0128] (Action and effect) According to the floating unit 1, the horizontally movable block 700 can be switched between a restrained state and a movable state by a permanent electromagnetic holder 440 housed inside the floating unit 1 (inside the storage space SS of the fixed block 100) and driven by electricity, so there is no need to connect a pipe to the outside of the floating unit 1 or to provide a separate device for pressurizing the fluid, and the entire system for operating the floating unit 1 can be made smaller.

[0129] Furthermore, according to the floating unit 1, the suction surface 441 of the permanent electromagnetic holder 440 of the vertically movable block 400 is exposed downward (to the opposite side of the bottom surface 110p) on the accommodating piston 420, so that the suction surface 441 of the permanent electromagnetic holder 440 can be adsorbed so as to come into surface contact with the suction plate 740, thereby more reliably restraining the horizontally movable block 700.

[0130] Furthermore, according to the floating unit 1, the attraction force of the permanent electromagnetic holder 440 can be utilized to correct positional deviation of the axis AX2 of the horizontally movable block 700 relative to the axis AX1 of the fixed block 100 in the horizontal direction or the θ direction, or in both directions.

[0131] Furthermore, according to the floating unit 1, in addition to the holding force of the horizontally movable block 700 due to the frictional force generated when the suction surface 441 of the permanent electromagnetic holder 440 is attracted to the suction plate 740, a further holding force of the horizontally movable block 700 is generated by the tip of the auxiliary pin 800 engaging with the auxiliary pin guide 500, so that the horizontally movable block 700 can be more reliably restrained.

[0132] Furthermore, according to the floating unit 1, for example, the floating unit can be used in an AGV (Automatic Guided Vehicle) by using a built-in power source for operating the AGV, without using a fluid supply device such as an air compressor.

[0133] (Modification) This invention is not limited to the above-described embodiment, and various modifications can be made based on the concept of this invention. Modifications of the present invention will be described below. In the description of the modifications, the same components as those of the floating unit 1 according to the above-described embodiment will be given the same reference numerals, and the description will be omitted. The following description will focus mainly on the different configurations.

[0134] As shown in FIGS. 48 and 49, a floating unit 1A according to a modified example includes a fixed block 100, a vertically movable block 400A, and a horizontally movable block 700A.

[0135] The vertically movable block 400A has a permanent electromagnetic holder 440A. The permanent electromagnetic holder 440A generates a larger attraction force than the permanent electromagnetic holder 440 of the floating unit 1 according to the above embodiment.

[0136] Moreover, the vertically movable block 400A does not have the center guide 480 and the auxiliary pin guide 500 that the vertically movable block 400 of the floating unit 1 of the above embodiment has.

[0137] Furthermore, the horizontally movable block 700A does not have the center pin 780 and the auxiliary pin 800 that the horizontally movable block 700 of the floating unit 1 of the above embodiment has.

[0138] According to the floating unit 1A, the vertical movable block 400A does not have a center guide 480, and the horizontally movable block 700A does not have a center pin 780. Therefore, even if the vertical movable block 400A (permanent electromagnetic holder 440A) is attracted to the horizontally movable block 700A, the positional deviation of the axis AX2 of the horizontally movable block 700A relative to the axis AX1 of the fixed block 100 is not corrected. That is, as shown in Fig. 49, the vertical movable block 400A can be attracted to the horizontally movable block 700A while the axis AX2 of the horizontally movable block 700A remains misaligned relative to the axis AX1 of the fixed block 100. As a result, according to the floating unit 1A, even if the horizontally movable block 700A is located in any position, the vertical movable block 400A is attracted to the horizontally movable block 700A, so that the horizontally movable block 700A can be stopped at that position.

[0139] In addition, the floating unit 1 according to the embodiment and the floating unit 1A according to the modified example have been described on the assumption that they are used with the top plate 840 (top surface 841p) facing downward, but they may be used with the top plate 840 (top surface 841p) facing upward. In other words, the top and bottom are not limited when using the floating unit 1 according to the embodiment and the floating unit 1A according to the modified example.

[0140] In addition, in the floating unit 1 according to the above embodiment, only the attraction plate 740 of the horizontally movable block 700 is made of a magnetic material, but the entire horizontally movable block 700 may be made of a magnetic material.

[0141] As described above, the embodiment of the present invention has been disclosed in the above description, but the present invention is not limited thereto. In other words, various modifications can be made to the above-described embodiments in terms of mechanism, shape, material, quantity, position, arrangement, etc., without departing from the scope of the technical idea and purpose of the present invention, and these are included in the present invention. [Explanation of symbols]

[0142] 1,1A floating unit 100 fixed blocks 110p bottom 120 Lock cylinder 122 Cylindrical part 122i1 Large diameter inner surface 122i2 Small diameter inner surface 122u outer surface 124 Expanded diameter part 124j Round corner 125 bolt holes 126 Bolt hole 127 holes 128 holes 129 holes 140 Piston guide 142i Inner surface 143 Bolt hole 144 holes 160 Body 162 Cylindrical part 162i Inner surface 162im female thread 164 Bottom plate part 165 Opening 166 Bolt holes 167 holes 167d Large diameter hole 167s small diameter hole 168 holes 180 Rotation control pin 182 Large diameter section 184 Small diameter section 200 Ball support plate (upper) 201 Inner surface 202 Outer surface 204 Top surface 206 holes 220 Ball support plate (lower) 221 Inner surface 240 Ball 260 Ball Cage (upper) 262 Ball Retaining Hole 264 Inner surface 280 Ball Cage (Lower) 300 Receptacle piston rotation stop pin 320 Storage piston support spring member 340 Magnet 360 Fixing block fixing bolt 400,400A Up and Down Movable Block 420 Containing Piston 422 Small diameter cylinder part 422i Inner surface 422u outer surface 423 holes 424 Ceiling 425 Bolt Hole 425d Large diameter hole 425s small diameter hole 426 Large diameter cylinder 426i Inner surface 426u outer surface 427 hole 428 holes 429 hole 430 Flange 430u outer surface 440,440A Permanent electromagnetic holder 441 Adsorption surface 442 Wiring (power line) 460 Permanent electromagnetic holder retaining bolt 480 Center Guide 482 Recess 500 Auxiliary Pin Guide 502 Recess 700,700A Horizontal Movable Block 720 Ball Support Plate (Medium) 722 Main body 723 Bolt hole 724 Center pin hole 725 Auxiliary pin hole 726 Bolt hole 727 Large diameter recess 730 Flange 740 Adsorption plate 743 Bolt hole 744 Center pin hole 745 Auxiliary pin hole 745d Large diameter hole 745s small diameter hole 746 Bolt hole 746d Large diameter hole 746s small diameter hole 760 Adsorption plate mounting bolt 780 Center Pin 782 Large diameter section 784 Small diameter section 786 Tip 800 Auxiliary Pin 802 Large diameter cylinder 803 Recess 804 Small diameter column 820 Auxiliary pin support spring member 840 Tabletop 841p Top 842 Main body 844 Bolt holes 844d Large diameter hole 844s small diameter hole 850 Expanded diameter part 852 Rotation control pin hole 854 Magnet hole 856 holes 858 screw hole 860 Top plate mounting bolt 880 Magnet SS Storage Space AX1 Axis of fixed block AX2 Axis of horizontal movable block

Claims

1. a fixed block having a bottom surface and an accommodation space formed therein; a vertically movable block that is accommodated in the accommodation space of the fixed block and configured to be slidable in the vertical direction; a horizontally movable block having a top surface, at least a portion of which is accommodated in the accommodation space of the fixed block, is disposed on the opposite side of the bottom surface from the vertically movable block, is at least a portion of which is made of a magnetic material and is configured to be slidable in a horizontal direction, a circumferential direction, or both; A floating unit comprising: the vertically movable block has an attraction surface for an object to be attracted, is configured to be able to attract the object to be attracted in an attraction ON state, and is configured to be able to detach the attracted object to be attracted in an attraction OFF state, the permanent electromagnetic holder having a first magnet, a second magnet, and a coil, and the operation of switching the attraction ON / OFF state is performed by instantaneously passing electricity through the coil to switch the magnetization direction of the first magnet when switching the attraction ON / OFF state; When the permanent electromagnetic holder is in an attraction-OFF state and is instantaneously energized to turn the permanent electromagnetic holder into an attraction-ON state, the vertically movable block is attracted to the horizontally movable block and stops the horizontally movable block; When the permanent electromagnetic holder in the suction ON state is momentarily energized and the permanent electromagnetic holder is turned to the suction OFF state, the vertical movable block separates from the horizontal movable block, and the horizontal movable block becomes movable. Floating unit.

2. The vertically movable block has, in addition to the permanent electromagnetic holder, a housing piston that houses the permanent electromagnetic holder with the adsorption surface of the permanent electromagnetic holder exposed in a direction opposite to the bottom surface, The horizontally movable block is An attraction plate made of a magnetic material capable of being attracted to the permanent electromagnetic holder; a ball contact plate disposed on the opposite side of the bottom surface from the suction plate, integrally connected to the suction plate, and supported on the fixed block so as to be slidable in a horizontal direction, a circumferential direction, or both; having 2. The floating unit according to claim 1.

3. the horizontally movable block further includes a center pin protruding from the suction plate toward the bottom surface side, The vertically movable block further includes a center guide having a recess formed in a tapered shape whose diameter increases toward the opposite side of the bottom surface, When the vertically movable block is attracted to the horizontally movable block, the tip of the center pin is guided by the tapered shape of the recess of the center guide, and a positional deviation of the axis of the horizontally movable block relative to the axis of the fixed block in the horizontal direction, the circumferential direction, or both directions is corrected.

3. The floating unit according to claim 2.

4. the horizontally movable block further includes an auxiliary pin protruding from the suction plate toward the bottom surface side, the vertically movable block further includes an auxiliary pin guide having a recess into which a tip end of the auxiliary pin can be fitted, When the vertically movable block is attracted to the horizontally movable block, a tip end of the auxiliary pin fits into a recess of the auxiliary pin guide. The floating unit according to claim 3.

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