Suction device

A suction device includes an adapter having in the interior thereof a supply passage to which a negative pressure fluid is supplied, a bellows connected to a distal end of the adapter, and a pad member disposed at a distal end of the bellows and to which a workpiece is attracted under suction. In addition, the suction device attracts the workpiece under suction by a negative pressure fluid which is supplied to the pad member through the supply passage and the bellows. An attachment which is capable of being tilted with respect to the axis of the bellows is provided in the interior of the bellows. In the attachment, a main body portion thereof is disposed in facing relation to a suction surface of a skirt, and a shaft portion is inserted into the supply passage at a time that the workpiece is attracted under suction.

CROSS-REFERENCE TO RELATED APPLICATION

This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2018-149077 filed on Aug. 8, 2018, the contents of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to a suction device capable of attracting-under-suction and transporting a workpiece under a supply action of a negative pressure fluid.

Description of the Related Art

Heretofore, a suction device has been known for attracting-under-suction and transporting a workpiece by a supplied negative pressure fluid. In such a suction device, for example, the workpiece, which is inclined with respect to a suction pad, is attracted under suction, and in such a case, the suction pad may not be kept in close contact with the workpiece, and the negative pressure fluid does not effectively act with respect to the workpiece, thus resulting in a suction defect.

Thus, in order to solve the aforementioned problem, for example, in the suction device disclosed in Japanese Utility Model Publication No. 05-035973, a hollow connecting screw is connected to a lower end of a fixture, and a spherical ball joint is provided on the lower end. In addition, a ball support retaining the suction pad is held in a rotatable manner with respect to the ball joint. Consequently, even in the case that the workpiece is inclined with respect to the suction pad, by the suction pad being tilted together with the ball support via the ball joint, the suction pad can be placed in close contact with the workpiece and attract the workpiece under suction.

SUMMARY OF THE INVENTION

In the suction device described above, for example, in the case of conveying a workpiece that is formed from a film in a bag-like shape and is filled with fluid contents, the contents may undergo movement due to inertia acting at a time when the workpiece is transported, and accompanying such movement, the workpiece may swing with respect to the suction pad. Consequently, for example, in the case that the inertial force acting on the workpiece is large relative to the suction force by the suction pad, the workpiece undergoes slippage with respect to the suction pad and a positional deviation occurs, or in the case that the workpiece is transported at a high speed, there is a concern that the workpiece may be dropped from the suction pad.

A general object of the present invention is to provide a suction device which is capable of reliably preventing positional deviation and dropping of a workpiece at a time that the workpiece is transported.

An aspect of the present invention is characterized by a suction device, comprising a body having in the interior thereof a passage to which a negative pressure fluid is supplied, a bellows connected to an end of the body, and a suction member disposed at an end of the bellows and to which a workpiece is attracted under suction, wherein the suction device attracts the workpiece under suction by a negative pressure fluid which is supplied to the suction member through the passage and the bellows;

wherein a tilting member which is capable of being tilted with respect to an axis of the bellows is provided in the interior of the bellows, and in the tilting member, one end thereof along an axial direction is disposed in facing relation to a suction surface on the suction member that is adapted to attract the workpiece, and another end thereof is inserted into the passage at a time that the workpiece is attracted under suction, together with being equipped in the interior thereof with a flow path communicating with the suction surface and through which the negative pressure fluid flows.

According to the present invention, in the suction device, the tilting member which is capable of being tilted with respect to the axis of the bellows is disposed in the interior of the bellows which is provided between the body and the suction member, and in the tilting member, one end thereof along the axial direction is disposed in facing relation to the suction surface on the suction member that attracts the workpiece, and another end thereof is inserted into the passage at a time that the workpiece is attracted under suction, together with being equipped in the interior thereof with the flow path communicating with the suction surface and through which the negative pressure fluid flows.

Accordingly, when a workpiece in which fluid contents are accommodated is attracted under suction and transported by the suction device, even in the case that the contents undergo movement due to the inertial force acting with respect to the workpiece, and the shape of the workpiece (the position of the center of gravity) is changed, the tilting member can be made to respond to such a situation by undergoing tilting inside the bellows in following relation to the change in the position of the center of gravity of the workpiece, together with the amount of tilting being regulated by the other end coming into abutment against the body inside the passage.

As a result, during conveyance of the workpiece which is attracted under suction by the suction device, even in the case that the inertial force acts with respect to the workpiece and the shape and the position of the center of gravity change, due to the tilting operation of the tilting member, it is possible to reliably prevent dropping off or positional deviation of the workpiece with respect to the suction device, and the workpiece can be transported to a predetermined position while reliably maintaining the attracted state of the workpiece.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

A suction device10, as shown inFIGS. 1 to 4, includes an adapter (body)12connected through piping to a non-illustrated negative pressure supply device, a bellows14connected to a lower end of the adapter12, a pad member (suction member)16formed at a lower end (distal end) of the bellows14, and an attachment (tilting member)18accommodated in the interior of the bellows14and the pad member16.

The adapter12is formed, for example, in a cylindrical shape from a metal material, and on a lower end thereof, a connecting part20is formed to which the bellows14is connected, whereas on an upper end thereof, a threaded portion24is formed to which a joint22is connected. Between the connecting part20and the threaded portion24in the adapter12, a flange member26is formed that projects in a direction perpendicular to the axial direction (the direction of arrows A and B).

In addition, a seal ring28is attached to the flange member26via an annular groove on an end surface on the side of the threaded portion24(in the direction of the arrow A). Moreover, when the joint22is connected with respect to the adapter12, the joint22abuts against the seal ring28, thereby preventing the negative pressure fluid from leaking between the two members.

Further, a supply passage (passage)30is formed in the interior of the adapter12along the axial direction (the direction of arrows A and B) so as to penetrate through the connecting part20, the flange member26, and the threaded portion24. The negative pressure fluid, which is supplied from the negative pressure supply device (not shown) through the piping and the joint22connected to the threaded portion24, is supplied to the supply passage30. Furthermore, in the supply passage30, a tapered portion32having a diameter that gradually expands toward the side of the bellows14(in the direction of the arrow B) which is located downward therefrom is formed at a position on an inner side of the connecting part20.

The bellows14is formed in a cylindrical shape, for example, from elastic rubber or the like, and has an expandable/contractible and bendable bellows structure in the axial direction. A cylindrical portion34which is formed in a cylindrical shape with a constant diameter is included on the upper end of the bellows14, and by being mounted in a manner so as to cover the connecting part20of the adapter12, the cylindrical portion34is connected coaxially with respect to the lower end of the adapter12.

Further, annular peak portions36that are expanded in diameter and annular valley portions (inner circumferential portions)38that are contracted in diameter are formed alternately along the axial direction (the direction of arrows A and B) on the bellows14. The pad member16, which is placed in contact with respect to the workpiece W (seeFIGS. 3 and 4) and applies suction thereto, is formed integrally on the lower end of the bellows14.

Moreover, the interior of the bellows14which is formed in a hollow shape functions as a flow path through which the negative pressure fluid is supplied and circulated, and under a supply action of the negative pressure fluid, is contracted in the axial direction toward the side of the adapter12(in the direction of the arrow A).

The pad member16includes a skirt40provided on the lower end of the bellows14. The skirt40is formed, for example, in a thin film annular shape from rubber or the like having an elasticity similar to that of the bellows14, and is formed so as to spread out obliquely downward (in the direction of the arrow B), together with being formed to be freely flexible. In addition, on the skirt40, the distal end thereof is a location that is placed in contact with respect to the workpiece W (seeFIG. 3). Moreover, the skirt40may be formed by way of two-color molding or the like using a material that differs from that of the bellows14.

The attachment18, for example, is formed of a resin material, and includes a main body portion42engaged with a distal end of the bellows14on the side of the pad member16(in the direction of the arrow B), and a shaft portion44which extends from the center of the main body portion42toward the side of the adapter12(in the direction of the arrow A). The main body portion42and the shaft portion44are formed in a straight line shape along the axial direction (in the direction of arrows A and B) of the suction device10.

The main body portion42is formed in a conical shape which is gradually expanded in diameter toward the side of the shaft portion44(in the direction of the arrow A) from one end side thereof on the side of the pad member16, and is engaged with the inner side of the lowermost (in the direction of the arrow B) annular peak portion36in the bellows14, and is thereby held integrally in the center of the lower end of the bellows14.

Further, the center on the one end of the main body portion42is formed with an arcuate shape in cross section which is of a concave shape in a direction (the direction of the arrow A) separating away from the workpiece W, and includes a first communication hole46opened at the center, and a plurality of second communication holes48opened on the outer circumferential side of the first communication hole46. In addition, the first and second communication holes46and48are formed to penetrate through the main body portion42in the axial direction (the direction of arrows A and B).

As shown inFIGS. 1 and 2, the shaft portion44is accommodated in the interior of the bellows14at a time that the negative pressure fluid is not being supplied and the workpiece W is not attracted under suction, is disposed at a predetermined distance in the radial direction with respect to the annular valley portions38of the bellows14, and is formed so as to project in the axial direction at a predetermined length from the center of the main body portion42.

Further, a spherical surface50which is formed in a substantially spherical shape is formed at the upper end of the shaft portion44, and as shown inFIGS. 3 and 4, at a time that the workpiece W to which the negative pressure fluid is supplied is attracted under suction, by the bellows14being contracted in the axial direction (in the direction of the arrow A), the upper end is inserted into the supply passage30of the adapter12, and the spherical surface50is placed in a position facing toward the tapered portion32.

Furthermore, a through hole52that penetrates along the axial direction (the direction of arrows A and B) is formed in the center of the shaft portion44, and the first communication hole46and the interior of the bellows14communicate via the through hole52.

Further, on the outer circumferential surface of the shaft portion44, a plurality of communication grooves54are formed which are recessed toward the inner side in the radial direction. The communication grooves54extend along the axial direction, and allow communication between the interior of the bellows14and the second communication holes48of the main body portion42.

In addition, in the interior of the bellows14and the pad member16, the attachment18is disposed so as to be capable of being tilted at a predetermined angle θ (seeFIG. 4) with respect to the axis L of the suction device10.

The suction device10according to the first embodiment of the present invention is constructed basically as described above. Next, operations and advantages thereof will be described. In this instance, as shown inFIGS. 3 and 4, a description will be given concerning a case in which a workpiece W formed of a thin film in a bag-like shape and in which fluid contents are contained in the interior thereof is attracted under suction and transported.

First, the suction device10is attached to an arm or the like of a non-illustrated transport apparatus, and is disposed in a movable manner, together with the adapter12being connected via piping and the joint22to a non-illustrated negative pressure supply device.

After having completed such preparatory operations, based on an operation of the arm of the non-illustrated transport apparatus, the suction device10is displaced downward (in the direction of the arrow B), and the skirt40is placed in close contact with respect to an upper part of the workpiece W that has been placed on a floor surface or the like, together with supplying a negative pressure fluid from the non-illustrated negative pressure supply device to the supply passage30of the adapter12via the piping and the joint22.

At this time, even in the case that the workpiece W is inclined, or when the upper part of the workpiece W is not flat, by an expanding/contracting operation of the bellows14corresponding to the workpiece W, and by the pad member16being elastically deformed, it is possible to follow the inclination and the like of the workpiece W and to securely place the pad member16in close contact therewith.

In addition, the skirt40or the pad member16is placed in close contact with the surface of the workpiece W, and the negative pressure fluid supplied to the supply passage30of the adapter12passes through the interior of the bellows14, and is supplied to the internal space of the pad member16from the through hole52and the communication grooves54of the attachment18, and through the first and second communication holes46and48.

Consequently, as shown inFIG. 3, by the negative pressure fluid supplied between the suction surface40aof the skirt40and the workpiece W, the upper part of the workpiece W is deformed and attracted under suction in a convex shape upwardly along the skirt40and the lower end of the main body portion42of the attachment18, while at the same time, the bellows14is contracted upwardly along the axial direction (in the direction of the arrow A), and the upper end of the attachment18is inserted into the supply passage30of the adapter12.

Then, as shown inFIG. 3, in a state in which the workpiece W is attracted under suction by the suction device10, by causing the workpiece W to be moved upwardly (in the direction of the arrow A) by the arm of the non-illustrated transport apparatus, the workpiece W becomes deformed so as to bend downward in the direction of gravity (the direction of the arrow B) due to the weight of the contents thereof, and accordingly, the skirt40elastically deforms in following relation to the shape of the upper part of the workpiece W that is attracted under suction, and becomes a downwardly bent curved shape.

The suction device10to which the workpiece W has been attracted under suction is moved in a substantially horizontal direction, for example, by a transport device, and is transported to a predetermined position. At this time, as shown inFIG. 4, the contents in the interior of the workpiece W undergo movement due to the inertia generated in a direction (the direction of the arrow D) opposite to the conveyance direction (the direction of the arrow C) of the suction device10(workpiece W) during conveyance thereof. Accompanying such movement, the position of the center of gravity changes simultaneously with the deformation of the bag-like workpiece W.

More specifically, when the inertial force acts on the workpiece W, the position of the center of gravity of the workpiece W that is not attracted under suction by the suction device10is moved in the direction in which inertia acts (in the direction of the arrow D), and the lower part of the workpiece W undergoes deformation in the direction in which inertia acts.

Accompanying the deformation (change in the position of the center of gravity) of the workpiece W, the skirt40is further elastically deformed in the direction (the direction of the arrow D) in which inertia acts, and together therewith, in a state in which the main body portion42of the attachment18has attracted the workpiece W under suction, the attachment18is tilted so as to be inclined at a predetermined angle θ in the movement direction of the workpiece W (the direction in which inertia acts) with respect to the axis L of the suction device10. Further, along with tilting of the attachment18, the bellows14on a side in the direction in which inertia acts (the direction of the arrow D) is further compressed in the axial direction, and on a side in the direction opposite to the direction in which inertia acts, i.e., in the direction of movement of the suction device10(the direction of the arrow C), the bellows14is deformed so as to expand slightly in the axial direction.

Consequently, together with the pad member16and the attachment18, the bellows14is also slightly inclined with respect to the axis L of the suction device10.

In the foregoing manner, even in the case that the position of the center of gravity of the workpiece W moves and the shape thereof changes, the pad member16to which the workpiece W is attracted under suction and the attachment18can be suitably moved in following relation to the direction (the direction of arrow D) in which the inertial force acts. Therefore, it is possible to reliably maintain a state in which the pad member16and the attachment18are kept in close contact with the upper part of the workpiece W and the workpiece W is attracted under suction, and the workpiece W is prevented from slipping and being deviated in position or falling off from the predetermined suction position on the pad member16due to the inertial force acting on the workpiece W during conveyance thereof.

Further, when the workpiece W undergoes deformation due to the inertia acting during conveyance thereof and the attachment18is tilted, the spherical surface50of the shaft portion44comes into contact with the tapered portion32of the adapter12, whereby a further tilting operation is restricted. Therefore, the amount of movement (amount of deformation) of the workpiece W due to inertia can be suppressed and maintained. Stated otherwise, by causing the attachment18to be tilted and enabling the workpiece W to be capable of swinging, it is possible to absorb the inertial force that acts on the workpiece W.

In addition, after the workpiece W has reached a predetermined position, supply of the negative pressure fluid to the supply passage30is stopped, whereby the attracted state of the workpiece W by the pad member16of the suction device10is released.

In the manner described above, according to the first embodiment, the attachment18is accommodated in a tiltable manner inside the bellows14that constitutes the suction device10, and the main body portion42, which is disposed at one end of the attachment18, is disposed in facing relation to the suction surface40aof the pad member16, whereas the shaft portion44, which is formed at the other end, is capable of being inserted into the supply passage30of the adapter12at the time that the workpiece W is attracted under suction.

Accordingly, in the case that a bag-like workpiece W in which fluid contents are accommodated is attracted under suction by the suction device10and the attachment18is tilted, even in the case that the contents are moved by the inertial force applied to the workpiece W, and the position of the center of gravity and the shape of the workpiece W are changed, the skirt40of the pad member16undergoes elastic deformation, while at the same time, the attachment18is inclined within the bellows14, whereby it is possible to be responsive to changes in shape in following relation to changes in the position of the center of gravity of the workpiece.

As a result, even in the case that a large inertial force acts with respect to the workpiece W while transporting the workpiece W which is attracted under suction by the suction device10, since the pad member16can be kept in close contact with respect to the workpiece W and the state of being attracted under suction can be maintained, it is possible to reliably prevent dropping off or positional deviation of the workpiece W with respect to the pad member16, and the workpiece W can be transported to a predetermined position while reliably maintaining the attracted state of the workpiece W.

Further, the shaft portion44of the attachment18includes the spherical surface50that can be brought into abutment with the tapered portion32of the supply passage30of the adapter12. Therefore, when the spherical surface50abuts against the tapered portion32due to the inertial force acting on the workpiece W, a further tilting operation of the attachment18can be restricted. As a result, an excessive change in the shape of the workpiece W due to inertia, and excessive movement in the direction in which inertia acts can be suitably prevented.

Furthermore, by providing the plurality of communication grooves54on the outer circumferential surface of the shaft portion44of the attachment18, as compared to a case of supplying the negative pressure fluid to the pad member16solely through the through hole52, of the negative pressure fluid that is supplied to the interior of the bellows14, the amount thereof that is supplied to the pad member16can be increased, and therefore, in the pad member16, the ability to attract the workpiece W under suction can be enhanced.

Further still, one end (the lower end) of the main body portion42in the attachment18is formed with a curved surface having an arcuate shape in cross section which is of an upwardly directed concave shape, and thus, when the workpiece W is attracted under suction, the workpiece W can be prevented from being drawn into the first and second communication holes46and48, and the occurrence of a suction defect can be reliably avoided.

Still further, in the suction device10, by providing the shaft portion44of the attachment18in the interior of the bellows14, even in the case that the workpiece W is swung by inertia and the bellows14is inclined with respect to the axis L of the suction device10, by the annular valley portions38coming into contact with the shaft portion44of the attachment18, further deformation of the bellows14is restricted. More specifically, by providing the shaft portion44of the attachment18, it is possible to suppress the amount of deformation of the bellows14when the workpiece W is swung, in comparison with a case in which the shaft portion44is not provided. Moreover, a clearance in the radial direction between the shaft portion44and the annular valley portions38in the bellows14may be appropriately set to such an extent that the two members do not come into contact with each other.

Further, in the manner described above, by providing a configuration in which it is possible to prevent deformation of the bellows14during conveyance of the workpiece W, deformation of the pad member16is also suppressed, and along therewith, it is possible to prevent positional deviation of the workpiece W with respect to the pad member16.

Next, a suction device70according to a second embodiment is shown inFIGS. 5 to 7. The same reference numerals are used to indicate the same constituent elements as those of the suction device10according to the above-described first embodiment, and detailed description of such features is omitted.

The suction device70according to the second embodiment differs from the suction device10according to the first embodiment, in that, in a pad member72, a plurality of first and second ribs76and78are provided on a suction surface74aof a skirt74for attracting the workpiece W under suction.

In the suction device70, as shown inFIGS. 5 to 7, on the skirt74that constitutes the pad member72, on the suction surface74aon the side of the workpiece W (in the direction of the arrow B), there are provided a plurality of first ribs76formed in facing relation to an outer edge part of the main body portion42of the attachment18, and a plurality of second ribs78disposed on an outer circumferential side with respect to the first ribs76.

The first and second ribs76and78are formed so as to project at a predetermined height, respectively, toward the side of the workpiece W with respect to the suction surface74aof the skirt74. A case will be described in which fifteen individual instances of the first and second ribs76and78are provided respectively on the skirt74.

As shown inFIG. 6, the first ribs76are formed with V-shapes in cross section having bottom portions on the inner circumferential side and opening toward the outer circumferential side of the skirt74as viewed from the axial direction of the suction device70. At bifurcated outer circumferential side end portions on the outer circumferential side, inclined portions82are formed which are inclined toward the central recesses80. More specifically, each of the first ribs76is formed in a manner so that one of the inclined portions82and the other of the inclined portions82form a pair in a symmetrical shape with the recess80being interposed therebetween.

Additionally, the plurality of first ribs76are arranged at equal intervals from one another along the circumferential direction (the direction of the arrow E) of the skirt74, and supply paths84are formed to which the negative pressure fluid is supplied between each of two adjacent ones of the first ribs76. The first ribs76and the supply paths84extend radially along radial directions of the skirt74.

Further, guide grooves86of the attachment18are disposed in facing relation on inner sides of the first ribs76and the supply paths84.

As shown inFIG. 6, the second ribs78are formed with V-shapes in cross section, which are bent to project toward the outer circumferential side of the skirt74as viewed from the axial direction of the suction device70. Among two of the first ribs76, which are arranged adjacent to each other, each of the second ribs78is arranged so as to straddle over an outer circumferential side end portion of one of the first ribs76and an outer circumferential side end portion of another of the first ribs76.

More specifically, concerning the second ribs78, central portions thereof, which face toward the supply paths84formed between adjacent ones of the first ribs76, make up top portions88that project maximally toward the outer circumferential side of the skirt74, and from the top portions88toward both ends thereof, the second ribs78are formed in an inclined manner toward inner sides in radial directions, respectively, so as to gradually approach toward the outer circumferential side end portions of the first ribs76.

The angles of inclination centered about the top portions88of the second ribs78are formed to be substantially the same as the angles of inclination of the inclined portions82on the first ribs76.

Next, a description will be given concerning a case in which the workpiece W is attracted under suction by the above-described suction device70. In this instance as well, a description will be given concerning a case in which the workpiece W, which is formed of a thin film in a bag-like shape and in which fluid contents are contained in the interior thereof, is attracted under suction and transported.

First, with respect to the suction device70, the negative pressure fluid is supplied to the supply passage30of the adapter12via the piping and the joint22from the non-illustrated negative pressure supply device, and by placing the skirt74of the pad member72in close contact with the surface of the workpiece W, the negative pressure fluid supplied to the supply passage30of the adapter12passes through the interior of the bellows14, and is supplied to the internal space of the pad member72from the first and second communication holes46and48of the attachment18. In addition, a portion of the negative pressure fluid supplied to the second communication holes48passes through the guide grooves86and flows to the side of the skirt74on the outer circumferential side thereof, and flows to the outer circumferential side along the respective supply paths84.

As a result, the upper part of the workpiece W that is placed in close contact with the skirt74is attracted under suction to the pad member72by the negative pressure fluid, and simultaneously, the bellows14undergoes contraction in the axial direction. At this time, since the outer edge part of the skirt74is held in close contact with the flat shaped upper part of the workpiece W, the negative pressure fluid supplied to the outer circumferential side along each of the supply paths84does not leak to the exterior, and the suction force applied with respect to the workpiece W is maintained.

Further, in the case that the shape of the workpiece W changes due to movement of the contents during conveyance of the workpiece W, then as shown inFIG. 7, accompanying the elastic deformation of the skirt74, the plurality of first ribs76approach toward each other in the circumferential direction (the direction of the arrow E), and the second ribs78approach toward the sides on the outer circumferential side end portions of the first ribs76and come into abutment against the outer circumferential side end portions, together with the first ribs76and the second ribs78approaching toward each other in the radial direction, whereby a state is brought about in which the outer circumferential sides of the supply paths84are blocked by the second ribs78.

Furthermore, accompanying the elastic deformation of the skirt74, by both ends of the second ribs78undergoing bending so as to approach toward each other, the second ribs78abut against the inclined portions82of the first ribs76and thereby block the supply paths84.

Therefore, the negative pressure fluid, which is supplied toward the outer circumferential side through each of the supply paths84in the skirt74, does not flow any further toward the outer circumferential side from the supply paths84due to the presence of the second ribs78, and the negative pressure fluid is retained within the supply paths84that are surrounded by the second ribs78and the first ribs76, whereby the deformed upper part of the workpiece W is reliably and suitably attracted under suction by the negative pressure fluid that is retained inside the respective supply paths84.

Further, even in the case that the lower surface of the attachment18is covered by the attracted workpiece W, the negative pressure fluid is securely supplied to the respective supply paths84of the skirt74by the guide grooves86that communicate with the second communication holes48and extend toward the outer circumferential side, thereby enabling the suction force applied with respect to the workpiece W to be maintained.

In the foregoing manner, according to the second embodiment, a plurality of first and second ribs76and78which project toward the workpiece W are provided on the suction surface74aof the pad member72that makes up the suction device70. In accordance with this feature, even in the case that the shape of the workpiece W is changed during conveyance thereof, the second ribs78cover the outer circumferential side end portions of the first ribs76accompanying the elastic deformation of the skirt74, and can thereby prevent leakage of the negative pressure fluid by blocking the outer sides of the respective supply paths84. Therefore, since the negative pressure fluid can be reliably maintained in a state in which the skirt74is in close contact with respect to the workpiece W, the suction force with respect to the workpiece W can be maintained, and the workpiece W can continue being reliably attracted under suction in a stable manner.

Furthermore, even in the case that an inertial force acts with respect to the workpiece W when the workpiece W is transported, the attachment18is caused to tilt with respect to the axis in the interior of the bellows14, and can be made to correspond to the change in shape in following relation to the change in the position of the center of gravity of the workpiece W, and by the pad member72always being kept in a state of being attracted under suction in close contact with respect to the workpiece W, dropping off or positional deviation of the workpiece W can be reliably prevented, and it is possible to transport the workpiece W to a predetermined position while maintaining the attracted state thereof.

The suction device according to the present invention is not limited to the embodiments described above. It is a matter of course that various alternative or additional configurations could be adopted therein without departing from the essence and gist of the present invention as set forth in the appended claims.