Lift device

Abstract

SOLUTION: To provide a lift device 10 equipped with a columnar body 12 and an annular elastic body 54, where the body comprises, at an end part in an axial direction, a flat surface 16 for holding a work-piece, and the elastic body is arranged at an outer periphery of the flat surface of the body and comprises an annular protruding part 58 protruding in the axial direction of the body more than the flat surface of the body, where the annular protruding part has a cross section in a circular arc-shape and air which is supplied to the body flows along the flat surface of the body and the annular protruding part of the elastic body.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a lift device that sucks and holds a workpiece by negative pressure generated by the Bernoulli effect.

Background Art

[0002] Conventionally, a non-contact transfer device that utilizes the Bernoulli effect generated by flowing air at high speed to hold and transfer a workpiece in a non-contact state is known.

[0003] For example, Patent Document 1 describes a non-contact suction gripping device that lifts a flat object (workpiece) such as glass. This suction gripping device is composed of a housing part and a nozzle part and utilizes the Bernoulli effect. The document also describes an embodiment in which a curved surface part is formed in the housing part to prevent the vibration phenomenon of a thin flat object. The flow of the injected air is changed by the Coandă effect in a direction away from the flat object by this curved surface part.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in a non-contact transfer device that utilizes the Bernoulli effect, when lifting the workpiece at a stage before stably holding the workpiece, the workpiece may collide with the device main body and a collision sound may occur. Also, scars due to the collision may remain on the workpiece.

[0006] The housing part of the suction gripping device in Patent Document 1 has a flat part facing the workpiece, and the curved surface part extending from the outer peripheral end of the flat part is bent in a direction away from the workpiece. Therefore, it is difficult to hold a workpiece curved upward.

[0007] An object of the present invention is to solve the above-described problems.

Means for Solving the Problems

[0008] The lift device according to the present invention includes a columnar body and an annular elastic body. The body has a flat surface for holding a workpiece at an axial end. The elastic body is disposed on the outer periphery of the flat surface of the body and has an annular protruding portion that protrudes in the axial direction of the body more than the flat surface of the body. The annular protruding portion has an arcuate cross section. The air supplied to the body flows along the flat surface of the body and the annular protruding portion of the elastic body.

Effects of the Invention

[0009] According to the lift device of the present invention, even when the workpiece collides with the elastic body during lifting of the workpiece, the impact sound is suppressed to be small by the elastic force of the elastic body, and no scar remains on the workpiece. Further, since the annular protruding portion of the elastic body protrudes below the first flat surface of the body, a wide negative pressure space exists on the inner peripheral side of the elastic body, and even a workpiece having a curved shape can be easily sucked and held.

[0010] Further, the air flowing along the annular protruding portion of the elastic body is discharged in the direction opposite to the workpiece due to the Coandă effect, so there is no risk of blowing away other workpieces placed close to the workpiece. Further, the workpiece comes into contact with the elastic body only during lifting and does not come into contact with the elastic body in the sucked and held state, so the adsorption marks due to contact with the elastic body can be minimized.

Brief Description of the Drawings

[0011]

Figure 1

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Figure 10

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Figure 12

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Figure 16

Figure 17

Embodiments for Carrying Out the Invention

[0012] In the following description, when terms related to up and down are used, they mean the up and down directions in the drawings excluding the exploded perspective views (Figs. 3, 9, 11, 13, 15, 17).

[0013] (First Embodiment) The lift device 10 according to the first embodiment of the present invention will be described with reference to Figs. 1 to 4. The lift device 10 is composed of a body 12, a deflector 38, and an elastic body 54.

[0014] As shown in Fig. 1, the columnar body 12 has an axis X in the vertical direction. The body 12 has a hole 14 at the center for attaching the deflector 38, and the hole 14 opens to the lower surface of the body 12. The axis of the hole 14 coincides with the axis X of the body 12. The lower surface of the body 12 is provided with an annular first flat surface 16 in a region near its outer periphery. The first flat surface 16 is perpendicular to the axis X of the body 12 and constitutes a work holding surface facing the work with a minute gap therebetween.

[0015] The opening edge of the hole 14 is continuous with the first flat surface 16 through a second flat surface 18, a first curved surface 20, and a second curved surface 22. The second flat surface 18 is perpendicular to the axis X of the body 12. The first curved surface 20 is a curved surface concave upward, and the second curved surface 22 is a curved surface bulging downward. The boundary between the first curved surface 20 and the second curved surface 22 is an inflection point in terms of the cross-sectional shape.

[0016] The body 12 includes a first port 24, a second port 26, and a third port 28. The first port 24 and the third port 28 open to the side surface of the body 12, and the second port 26 opens to the upper surface of the body 12. The first port 24 is a port for generating a negative pressure in the space in contact with the lower surface of the body 12, and air from an air supply source (not shown) is introduced into the body 12 through the first port 24. The first port 24 is used when it is desired to supply air from the air supply source to the body 12 from the side surface.

[0017] The second port 26, like the first port 24, is a port for generating a negative pressure in the space in contact with the lower surface of the body 12. The second port 26 is used when it is desired to supply air from an air supply source from the upper surface of the body 12. FIG. 1 shows a usage mode in which air from an air supply source is supplied from the side surface of the body 12, and the second port 26 is blocked by the first plug 30.

[0018] The third port 28 is used to measure the pressure in the space below the body 12 and to confirm the presence of a workpiece. Also, the third port 28 is used to generate a positive pressure in the space below the body 12 and to destroy a negative pressure (vacuum pressure). The third port 28 is located on the side opposite to the first port 24 with the axis X of the body 12 in between. In the usage mode shown in FIG. 1, since the third port 28 is not used, the third port 28 is blocked by the second plug 32. When the third port 28 is used, a pressure sensor (not shown) is attached to the pipe connected to the third port 28. Also, air from an air supply source is introduced into the body 12 through the third port 28.

[0019] The columnar deflector 38 includes a main body portion 40 fitted into the hole portion 14 of the body 12 and a flange portion 42 extending radially outward from the lower portion of the main body portion 40. The deflector 38 is fixed to the body 12 by screwing a bolt (not shown) inserted from the upper surface of the body 12 into the main body portion 40. The upper and lower surfaces of the flange portion 42 are perpendicular to the axis X of the body 12, and the lower surface of the flange portion 42 is located slightly above the first flat surface 16 of the body 12.

[0020] The side surface of the main body portion 40 of the deflector 38 has an annular groove 44 continuous with the upper surface of the flange portion 42. The annular groove 44 of the deflector 38 communicates with the first port 24 and the second port 26 at a predetermined location in the circumferential direction. The annular groove 44 of the deflector 38 cooperates with the wall surface of the hole portion 14 of the body 12 to form a flow path for the air supplied from the first port 24 or the second port 26.

[0021] The upper surface of the flange portion 42 abuts against the second flat surface 18 of the body 12 and has a plurality of nozzle grooves 46 extending radially. The plurality of nozzle grooves 46 communicate with the annular groove 44 and constitute a flow path for air supplied from the first port 24 or the second port 26. The total flow area of the plurality of nozzle grooves 46 is smaller than the flow area of the annular groove 44, and the nozzle grooves 46 function to increase the flow velocity of the air. The air supplied from the first port 24 or the second port 26 passes through the annular groove 44 of the main body portion 40 and the nozzle grooves 46 of the flange portion 42, and is radially ejected while increasing the flow velocity. The air ejected from the nozzle grooves 46 flows along the first curved surface 20, the second curved surface 22, and the first flat surface 16 of the body 12.

[0022] The deflector 38 has a vertical passage 48 penetrating in the vertical direction, and the body 12 has a horizontal passage 36. One end of the horizontal passage 36 of the body 12 communicates with the third port 28, and the other end of the horizontal passage 36 of the body 12 communicates with the vertical passage 48 of the deflector 38. The air supplied from the third port 28 flows downward from the deflector 38 through the horizontal passage 36 of the body 12 and the vertical passage 48 of the deflector 38. The main body portion 40 of the deflector 38 is equipped with a first seal 50 and a second seal 52 for sealing between the annular groove 44 and the vertical passage 48.

[0023] As shown in FIGS. 2 and 3, the annular elastic body 54 is disposed on the outer periphery of the first flat surface 16 of the body 12 and is attached to the outer periphery of the lower end portion of the body 12. The elastic body 54 is made of an elastomer such as rubber or polyurethane resin. The upper portion of the elastic body 54 is provided with an annular convex portion 56 protruding radially inward. The elastic body 54 is attached to the body 12 by fitting the convex portion 56 of the elastic body 54 into the annular mounting groove 34 provided on the outer periphery of the lower end portion of the body 12.

[0024] The lower part of the elastic body 54 is provided with an annular protruding portion 58 that protrudes downward from the first flat surface 16 of the body 12. The annular protruding portion 58 has a semi-circular (arc-shaped) cross-section and protrudes downward by a predetermined height H1 from the first flat surface 16 of the body 12 over the entire circumference of the elastic body 54. As described above, the air supplied from the first port 24 or the second port 26 is radially injected through the annular groove 44 and the nozzle groove 46 of the deflector 38 and flows along the first curved surface 20, the second curved surface 22, and the first flat surface 16 of the body 12. The air that has flowed along the first flat surface 16 further flows along the surface shape of the annular protruding portion 58 of the elastic body 54. The air that has flowed along the annular protruding portion 58 of the elastic body 54 is discharged outward upward or obliquely upward due to the Coanda effect. In FIG. 2, the air flow is indicated by dotted arrows.

[0025] Next, the operation when the work W is sucked and held by the lift device 10 will be described. The lift device 10 is attached to, for example, the arm of a transfer device. The work W is placed at a predetermined location such as the floor surface. Here, as the shape of the work W, a curved shape that bulges upward is assumed (see FIG. 4).

[0026] The transfer device is driven, and the lift device 10 approaches the work W from above the work W. At the same time, air from the air supply source is supplied to the first port 24 of the lift device 10. The air supplied to the first port 24 passes through the annular groove 44 and the nozzle groove 46 of the deflector 38 and then flows along the first curved surface 20, the second curved surface 22, and the first flat surface 16 of the body 12. The air that has flowed along the first flat surface 16 flows along the annular protruding portion 58 of the elastic body 54 due to the Coanda effect.

[0027] When the distance between the lifting device 10 and the workpiece W becomes within a predetermined range, the air flow velocity becomes extremely high. Therefore, due to the Bernoulli effect, negative pressure is generated in the space S on the inner circumferential side of the annular protruding portion 58 of the elastic body 54, causing the workpiece W to lift and be sucked by the lifting device 10. The lifted workpiece W abuts against the annular protruding portion 58 of the elastic body 54 by its momentum and then separates from the elastic body 54 due to the reaction. Thereafter, the workpiece W is sucked by the lifting device 10 again due to the negative pressure existing in the space S on the inner circumferential side of the annular protruding portion 58 of the elastic body 54.

[0028] If it is assumed that the workpiece W abuts against the entire circumference of the elastic body 54, the air flow is blocked and the Bernoulli effect disappears, and the suction holding force of the workpiece W becomes zero. Therefore, the workpiece W settles in a state where a minute gap corresponding to the weight of the workpiece W is secured between the workpiece W and the annular protruding portion 58 of the elastic body 54 and is sucked and held by the lifting device 10. At this time, as shown in FIG. 4, a part of the workpiece W enters the space S on the inner circumferential side of the annular protruding portion 58 of the elastic body 54. Thereafter, the conveying device is driven, and the workpiece W is conveyed to a predetermined location while being held in a stable posture. Here, the case of sucking and holding the curved workpiece W has been assumed, but the non-curved workpiece W can also be sucked and held in the same manner.

[0029] According to the lifting device 10, the following operational effects are achieved. First, the air flowing along the annular protruding portion 58 of the elastic body 54 is discharged outward upward or obliquely upward due to the Coanda effect, so there is no risk of blowing away other workpieces W placed on the floor surface or the like. Second, even if the workpiece W collides with the elastic body 54 during the lifting of the workpiece W, the elastic force of the elastic body 54 suppresses the collision sound to a small level, and no scar remains on the workpiece W.

[0030] Third, since the annular protruding portion 58 of the elastic body 54 protrudes below the first flat surface 16 of the body 12, a wide negative pressure space exists on the inner peripheral side of the elastic body 54, and a work piece W having a curved shape bulging upward can also be sucked and held. Fourth, the work piece W contacts the elastic body 54 only during lifting and does not contact the elastic body 54 in the sucked and held state, so that adsorption marks due to contact with the elastic body 54 can be minimized as much as possible. Fifth, when the work piece W is in a thin plate shape, vibration of the work piece W due to air discharge is suppressed by the elastic body 54.

[0031] (Second Embodiment) Next, a lift device according to a second embodiment of the present invention will be described with reference to FIG. 5. The lift device according to the second embodiment is different from the lift device 10 according to the first embodiment in the shape of the elastic body 70 and the configuration for attaching the elastic body 70. Hereinafter, the description will focus on matters related to this difference. In the following description, when the same reference numerals as those in the first embodiment are used, it means that the members and the like are equivalent to the members and the like in the first embodiment. The same applies to the third to eighth embodiments.

[0032] The annular elastic body 70 is disposed on the outer periphery of the first flat surface 16 of the body 12 and attached to the outer periphery of the lower end portion of the body 12. The elastic body 70 has a circular cross section and is made of an elastomer such as rubber or polyurethane resin. The outer periphery of the lower end portion of the body 12 is provided with an annular mounting groove 74 whose width becomes narrower as it approaches the inlet. When the elastic body 70 is pushed into the mounting groove 74 of the body 12 while being deformed, the elastic body 70 is held in the mounting groove 74 by its restoring force. Thereby, the elastic body 70 is attached to the body 12.

[0033] The elastic body 70 projects downward by a predetermined height H2 from the first flat surface 16 of the body 12 over its entire circumference. In other words, the elastic body 70 has an annular protruding portion 72 that protrudes below the first flat surface 16 of the body 12, and the annular protruding portion 72 has an arcuate cross section. The air jetted radially from the nozzle groove 46 of the deflector 38 flows along the first curved surface 20, the second curved surface 22, and the first flat surface 16 of the body 12. The air flowing along the first flat surface 16 flows along the surface shape of the annular protruding portion 72 of the elastic body 70 due to the Coandă effect and is discharged to the outside.

[0034] According to the lift device according to the second embodiment, since the elastic body 70 having a circular cross section is used, the elastic body 70 can be easily manufactured or obtained.

[0035] (Third Embodiment) Next, a lift device according to the third embodiment of the present invention will be described with reference to FIGS. 6 and 7. The lift device according to the third embodiment is different from the lift device 10 according to the first embodiment in the configuration of the elastic body 80. Hereinafter, the description will focus on matters related to this difference.

[0036] The annular elastic body 80 is disposed on the outer periphery of the first flat surface 16 of the body 12 and is attached to the outer periphery of the lower end portion of the body 12. The elastic body 80 is made of an elastomer such as rubber or polyurethane resin. The elastic body 80 includes a main body portion 82 facing the workpiece, a fixing portion 86 attached to the body 12, and a bellows-shaped connecting portion 90 connecting the main body portion 82 to the fixing portion 86.

[0037] The fixing portion 86 of the elastic body 80 includes an annular convex portion 88 protruding radially inward. The elastic body 80 is attached to the body 12 by fitting the convex portion 88 of the fixing portion 86 into an annular mounting groove 92 provided on the outer periphery of the lower end portion of the body 12. The connecting portion 90 of the elastic body 80 is bendable and allows the vertical displacement of the main body portion 82. FIG. 7 shows a state where the main body portion 82 is displaced upward.

[0038] The main body portion 82 of the elastic body 80 includes an annular protruding portion 84 that protrudes downward from the first flat surface 16 of the body 12. The annular protruding portion 84 has a semi-circular (arc-shaped) cross-section. As shown in FIG. 6, when no vertical force is applied to the connecting portion 90, the annular protruding portion 84 protrudes downward from the first flat surface 16 of the body 12 by a predetermined height H3 over the entire circumference of the elastic body 80. The air jetted radially from the nozzle groove 46 of the deflector 38 flows along the first curved surface 20, the second curved surface 22, and the first flat surface 16 of the body 12. The air flowing along the first flat surface 16 flows along the surface shape of the annular protruding portion 84 of the elastic body 80 due to the Coanda effect and is discharged to the outside.

[0039] According to the lift device according to the third embodiment, since the elastic body 80 includes the bellows-shaped connecting portion 90, the collision sound when the workpiece collides with the elastic body 80 can be further reduced, and it is possible to reliably prevent the workpiece from leaving scars.

[0040] (Fourth Embodiment) Next, the lift device 100 according to the fourth embodiment of the present invention will be described with reference to FIGS. 8 and 9. The lift device 100 is different from the lift device 10 according to the first embodiment in the configuration for attaching the elastic body 102. Hereinafter, the matters related to this difference will be mainly described.

[0041] The lift device 100 includes a cylindrical holder 108 that holds the elastic body 102. The annular elastic body 102 is disposed on the outer periphery of the first flat surface 16 of the body 12 and is attached to the body 12 via the holder 108. The elastic body 102 is made of an elastomer such as rubber or polyurethane resin. The upper portion of the elastic body 102 includes an annular convex portion 104 that protrudes radially outward. The elastic body 102 is attached to the holder 108 by fitting the convex portion 104 of the elastic body 102 into an annular mounting groove 110 provided on the inner periphery of the lower end portion of the holder 108.

[0042] The holding member 108 has a plurality of bolt insertion holes 112 penetrating in the radial direction. The outer peripheral portion of the body 12 has screw holes 114 at positions corresponding to the bolt insertion holes 112 of the holding member 108. The holding member 108 is attached to the body 12 by screwing bolts 116 inserted through the bolt insertion holes 112 of the holding member 108 into the screw holes 114 of the body 12.

[0043] The lower part of the elastic body 102 is provided with an annular protruding portion 106 that protrudes below the first flat surface 16 of the body 12. The annular protruding portion 106 has a semi-circular (arc-shaped) cross-section and protrudes downward from the first flat surface 16 of the body 12 by a predetermined height H4 over the entire circumference of the elastic body 102. The air jetted radially from the nozzle groove 46 of the deflector 38 flows along the first curved surface 20, the second curved surface 22, and the first flat surface 16 of the body 12. The air flowing along the first flat surface 16 flows along the surface shape of the annular protruding portion 106 of the elastic body 102 due to the Coanda effect and is discharged to the outside.

[0044] According to the lift device 100, since the elastic body 102 is attached to the body 12 via the holding member 108, the attachment of the elastic body 102 is easy. Note that, as will be described later, the engagement hole indicated by reference numeral 192 is an engagement hole used in the seventh embodiment. The body 12 having the screw holes 114 and the engagement holes 192 can be commonly used in the fifth to eighth embodiments.

[0045] (Fifth Embodiment) Next, the lift device 120 according to the fifth embodiment of the present invention will be described with reference to FIGS. 10 and 11. The lift device 120 is different from the lift device 10 according to the first embodiment in the shape of the elastic body 122 and the configuration for attaching the elastic body 122. Hereinafter, the description will focus on the matters related to this difference.

[0046] The lift device 120 includes a cylindrical holder 126 that holds the elastic body 122. The annular elastic body 122 is disposed on the outer periphery of the first flat surface 16 of the body 12 and is attached to the body 12 via the holder 126. The elastic body 122 has a circular cross-section and is made of an elastomer such as rubber or polyurethane resin. The holder 126 is provided with a mounting groove 128 having a semi-circular cross-section. The elastic body 122 is attached to the body 12 by being sandwiched between the inner surface of the mounting groove 128 and the side surface 132 of the body 12.

[0047] The holder 126 has a plurality of bolt insertion holes 130 that penetrate in the radial direction. The outer peripheral portion of the body 12 has screw holes 114 at positions corresponding to the bolt insertion holes 130 of the holder 126. The holder 126 is attached to the body 12 by screwing bolts 116 inserted through the bolt insertion holes 130 of the holder 126 into the screw holes 114 of the body 12.

[0048] The elastic body 122 protrudes downward by a predetermined height H5 from the first flat surface 16 of the body 12 over its entire circumference. In other words, the elastic body 122 includes an annular protruding portion 124 that protrudes below the first flat surface 16 of the body 12, and the annular protruding portion 124 has an arcuate cross-section. The air jetted radially from the nozzle groove 46 of the deflector 38 flows along the first curved surface 20, the second curved surface 22, and the first flat surface 16 of the body 12. The air flowing along the first flat surface 16 flows along the surface shape of the annular protruding portion 124 of the elastic body 122 due to the Coandă effect and is discharged to the outside.

[0049] According to the lift device 120, since the elastic body 122 is attached to the body 12 using the holder 126, the attachment of the elastic body 122 is easy. Also, since the elastic body 122 having a circular cross-section is used, the manufacturing or acquisition of the elastic body 122 is easy.

[0050] (Sixth Embodiment) Next, the lift device 140 according to the sixth embodiment of the present invention will be described with reference to FIGS. 12 and 13. The lift device 140 is different from the lift device 10 according to the first embodiment in the configuration for attaching the elastic body 142. Further, the lift device 140 is different from the lift device 10 in the configuration for guiding the discharged air. Hereinafter, the matters related to these differences will be mainly described.

[0051] The lift device 140 includes a cylindrical holder 148 that holds the elastic body 142. The annular elastic body 142 is disposed on the outer periphery of the first flat surface 16 of the body 12 and is attached to the body 12 via the holder 148. The elastic body 142 is made of an elastomer such as rubber or polyurethane resin. The upper part of the elastic body 142 is provided with an annular convex portion 144 that protrudes radially outward. The elastic body 142 is attached to the holder 148 by fitting the convex portion 144 of the elastic body 142 into an annular mounting groove 150 provided on the inner periphery of the lower end portion of the holder 148.

[0052] The holder 148 has a plurality of bolt insertion holes 152 that penetrate in the radial direction. The outer peripheral portion of the body 12 has screw holes 114 at positions corresponding to the bolt insertion holes 152 of the holder 148. The holder 148 is attached to the body 12 by screwing bolts 116 inserted through the bolt insertion holes 152 of the holder 148 into the screw holes 114 of the body 12.

[0053] Further, the lift device 140 includes a cylindrical cover body 158 that guides the discharged air upward above the lift device 140. The cover body 158 is composed of a thin cylindrical portion 160 and a thin disk portion 162. The disk portion 162 is connected to the upper end of the cylindrical portion 160 via a plurality of connection pieces 164 extending from its outer periphery. A first gap 166 serving as an air flow path is formed between the outer peripheral surface of the holder 148 and the inner peripheral surface of the cylindrical portion 160. Further, a second gap 168 serving as an air flow path is formed between adjacent connection pieces 164. The cover body 158 is attached to the holder 148 using bolts (not shown). Reference numeral 156 indicates a hole through which the bolts are inserted.

[0054] The lower part of the elastic body 142 is provided with an annular protruding portion 146 that protrudes downward from the first flat surface 16 of the body 12. The annular protruding portion 146 has a semi-circular (arc-shaped) cross-section and protrudes downward from the first flat surface 16 of the body 12 by a predetermined height H6 across the entire circumference of the elastic body 142. The air jetted radially from the nozzle groove 46 of the deflector 38 flows along the first curved surface 20, the second curved surface 22, and the first flat surface 16 of the body 12. The air flowing along the first flat surface 16 flows along the surface shape of the annular protruding portion 146 of the elastic body 142 due to the Coanda effect.

[0055] The air flowing along the annular protruding portion 146 of the elastic body 142 flows upward or obliquely upward due to the Coanda effect, and then is guided to the first gap 166 between the outer peripheral surface of the holder 148 and the inner peripheral surface of the cylindrical portion 160, and further discharged to the outside through the second gap 168 between the adjacent connecting pieces 164. In FIG. 12, the air flow is indicated by dotted arrows. An exhaust pipe (not shown) can be connected to the outlet of the second gap 168.

[0056] According to the lift device 140, since the elastic body 142 is attached to the body 12 via the holder 148, the attachment of the elastic body 142 is easy. Further, since it is provided with a cover body 158 that guides the discharged air upward of the lift device 140, it is possible to collect and discharge the air at one location.

[0057] (Seventh Embodiment) Next, the lift device 170 according to the seventh embodiment of the present invention will be described with reference to FIGS. 14 and 15. The lift device 170 is different from the lift device 10 according to the first embodiment in that it includes an attachment member 172 suitable for sucking a flexible sheet-like workpiece. Further, the lift device 170 is different from the lift device 10 in the configuration of attaching the elastic body 186. Hereinafter, the description will focus on the matters related to these differences.

[0058] The attachment member 172 is composed of an annular ring portion 174 facing the lower surface of the deflector 38, a plurality of cross-bridge portions 176 extending radially from the outer periphery of the ring portion 174, and a cylindrical cover wall 178 connected to the outer ends of the plurality of cross-bridge portions 176. The plurality of cross-bridge portions 176 are arranged at equal angles in the circumferential direction. When sucking a flexible workpiece, for example, a sheet-like workpiece, the plurality of cross-bridge portions 176 suppress the intrusion of the workpiece into the body 12 and prevent the vibration or flutter of the workpiece.

[0059] The cover wall 178 of the attachment member 172 is provided with a plurality of claw portions 180 formed by being notched in the vertical direction. Each claw portion 180 has elasticity and is provided with a convex portion 182 protruding radially inward at the tip. The outer peripheral portion of the body 12 has an engagement hole 192 at a position corresponding to the convex portion 182 of each claw portion 180. When the convex portion 182 of the claw portion 180 engages with the engagement hole 192 of the body 12, the attachment member 172 is attached to the body 12. The cross-bridge portion 176 of the attachment member 172 abuts against the first flat surface 16 of the body 12, but the flow of air along the first flat surface 16 is not obstructed by the cross-bridge portion 176.

[0060] The annular elastic body 186 is disposed on the outer periphery of the first flat surface 16 of the body 12 and is attached to the body 12 via the attachment member 172. The elastic body 186 is composed of an elastomer such as rubber or polyurethane resin. The upper portion of the elastic body 186 is provided with a plurality of elongated convex portions 188 protruding radially inward. The cover wall 178 of the attachment member 172 has an elongated engagement hole 184 at a position corresponding to the convex portion 188 of the elastic body 186. When the convex portion 188 of the elastic body 186 engages with the engagement hole 184 of the cover wall 178, the elastic body 186 is attached to the attachment member 172.

[0061] The lower part of the elastic body 186 is provided with an annular protruding portion 190 that protrudes below the first flat surface 16 of the body 12. The annular protruding portion 190 has a semi-circular (arc-shaped) cross-section and protrudes downward by a predetermined height H7 from the first flat surface 16 of the body 12 across the entire circumference of the elastic body 186. The air jetted radially from the nozzle groove 46 of the deflector 38 flows along the first curved surface 20, the second curved surface 22, and the first flat surface 16 of the body 12. The air flowing along the first flat surface 16 flows along the surface shape of the annular protruding portion 190 of the elastic body 186 due to the Coanda effect and is discharged to the outside.

[0062] According to the lift device 170, since the attachment member 172 having the cross-linked portion 176 is attached, it is possible to prevent the vibration of the flexible workpiece. Further, since the elastic body 186 is attached using the attachment member 172, the attachment of the elastic body 186 is easy.

[0063] (Eighth Embodiment) Next, the lift device 200 according to the eighth embodiment of the present invention will be described with reference to FIGS. 16 and 17. The lift device 200 is different from the lift device 10 according to the first embodiment in that it includes an attachment member 202 suitable for sucking a flexible sheet-like workpiece. Further, the lift device 200 is different from the lift device 10 in the configuration for attaching the elastic body 220. Hereinafter, the description will focus on matters related to these differences.

[0064] The attachment member 202 is composed of a plurality of spoke portions 204, a first outer peripheral ring portion 210, a second outer peripheral ring portion 212, and an inner peripheral ring portion 214. The spoke portion 204 has a V-shaped portion 206 extending in the radial direction and a vertical portion 208 bent perpendicularly from both ends of the V-shaped portion 206. The plurality of spoke portions 204 are arranged at equal intervals in the circumferential direction. The first outer peripheral ring portion 210 is connected to the bent portion of each spoke portion 204. The second outer peripheral ring portion 212 is connected to the vertical portion 208 of each spoke portion 204. The inner peripheral ring portion 214 is connected near the tip of the V-shaped portion 206 of each spoke portion 204. When sucking a flexible workpiece such as a sheet, the intrusion of the workpiece into the body 12 is suppressed by the V-shaped portion 206 of the spoke portion 204, and the vibration or wobbling of the workpiece is prevented.

[0065] The vertical portions 208 of the plurality of spoke portions 204, the first outer peripheral ring portion 210, and the second outer peripheral ring portion 212 form a grid-like opening 216 arranged in the circumferential direction. A plurality of bolts 218 each having a head sized to fit snugly into the opening 216 are inserted into respective predetermined openings 216 and screwed into screw holes 114 provided in the body 12. Thereby, the attachment member 202 is attached to the body 12. The spoke portion 204 of the attachment member 202 abuts against the first flat surface 16 of the body 12 at the V-shaped portion 206, but the flow of air along the first flat surface 16 is not obstructed by the spoke portion 204.

[0066] The annular elastic body 220 is disposed on the outer periphery of the first flat surface 16 of the body 12. The elastic body 220 is composed of an elastomer such as rubber or polyurethane resin. The elastic body 220 is insert-molded so as to be in close contact with the first outer peripheral ring portion 210 of the attachment member 202. That is, the elastic body 220 is integrally molded with the attachment member 202.

[0067] The lower part of the elastic body 220 is provided with an annular protruding portion 222 that protrudes downward from the first flat surface 16 of the body 12. The annular protruding portion 222 has a semi-circular (arc-shaped) cross-section and protrudes downward by a predetermined height H8 from the first flat surface 16 of the body 12 over the entire circumference of the elastic body 220. The air jetted radially from the nozzle groove 46 of the deflector 38 flows along the first curved surface 20, the second curved surface 22, and the first flat surface 16 of the body 12. The air flowing along the first flat surface 16 flows along the surface shape of the annular protruding portion 222 of the elastic body 220 due to the Coanda effect and is discharged to the outside.

[0068] According to the lift device 200, since the attachment member 202 having the spoke portion 204 is attached, it is possible to prevent the vibration of the flexible workpiece. Further, since the elastic body 220 is integrally formed with the attachment member 202 by insert molding, the attachment process of the elastic body 220 is unnecessary.

[0069] The lift device 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. For example, in the sixth embodiment, the holder 148 and the cover body 158 are provided, and the cover body 158 is attached to the holder 148, but an embodiment in which the cover body is provided without the holder is also conceivable. In that case, the cover body is attached to the body.

Explanation of reference numerals

[0070] 10, 100, 120, 140, 170, 200... Lift device 12... Body 16... First flat surface (flat surface) 34, 74, 92, 110, 128, 150... Mounting groove 54, 70, 80, 102, 122, 142, 186, 220... Elastic body 56, 88, 104, 144, 182... Convex portion 58, 72, 84, 106, 124, 146, 190, 222... Annular protruding portion 82... Main body portion 86... Fixed portion 90... Connecting portion 108, 126, 148... Holder 158…Cover body 172, 202…Attachment member 174…Ring part 176…Crosslinked part 178…Cover wall 184…Engagement hole 204…Spoke part 210…First outer peripheral ring part (outer peripheral ring part) W…Workpiece

Claims

1. A lift device comprising a cylindrical body and an annular elastic body, The body has a flat surface for holding a workpiece at an axial end, The elastic body is disposed on the outer periphery of the flat surface of the body and has an annular protruding portion that protrudes in the axial direction of the body from the flat surface of the body. The annular protruding portion has an arcuate cross section, Air supplied to the body flows along the flat surface of the body and the annular protruding portion of the elastic body, whereby the workpiece is sucked and held in a non-contact state.

2. In the lift device according to claim 1, The elastic body has an annular convex portion that protrudes radially inward, and the convex portion fits into an annular mounting groove provided in the body.

3. In the lift device according to claim 1, The elastic body has a circular cross section, the body has an annular mounting groove that is narrower closer to the entrance, and the elastic body is held in the mounting groove.

4. In the lift device according to claim 1, The elastic body includes a main body portion having the annular protruding portion, a fixing portion attached to the body, and a bellows-shaped connecting portion connecting the main body portion to the fixing portion.

5. In the lift device according to claim 1, It includes a holder for holding the elastic body, and the holder is attached to the body.

6. In the lift device according to claim 5, The elastic body has an annular convex portion that protrudes radially outward, and the convex portion fits into an annular mounting groove provided in the holder.

7. In the lift device according to claim 5, The elastic body has a circular cross-section, the holder includes a mounting groove having a semi-circular cross-section, and the elastic body is a lift device sandwiched between the inner surface of the mounting groove and the side surface of the body.

8. In the lift device according to claim 1, A lift device including a cylindrical cover body for guiding the discharged air.

9. In the lift device according to claim 1, A lift device including an attachment member composed of an annular ring portion, a plurality of cross-bridge portions radially extending from the outer periphery of the ring portion, and a cylindrical cover wall connected to the outer ends of the cross-bridge portions.

10. In the lift device according to claim 9, The elastic body is a lift device attached to the attachment member.

11. In the lift device according to claim 10, The elastic body includes a plurality of convex portions protruding radially inward, and the convex portions engage with the engagement holes of the cover wall.

12. In the lift device according to claim 1, A lift device including an attachment member including a plurality of spoke portions and an outer peripheral ring portion.

13. In the lift device according to claim 12, The elastic body is insert-molded so as to be in close contact with the outer peripheral ring portion.

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