JP2013116522A - Gripping device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gripping device capable of restraining the reduction of expansion and the contraction speed of an elastic body that grips an object by expansion and contraction resulting from the supply and the discharge of a fluid.SOLUTION: The gripping device 10 includes a cylindrical member 12, a circular elastic membrane 22 arranged along an inner peripheral surface 12B of the cylindrical member 12 and forming a sealed space 26 between the inner peripheral surface 12B of the cylindrical member 12 and the elastic membrane 22 and gripping a gripping target object 100 by being expanded in the center axis CL of the cylindrical member 12 by supplying the fluid F to the sealed space 26, and a supplying and discharging passage 20 (one example of a circulation passage) arranged on the cylindrical member 12 and is used for the circulation of the fluid F to the sealed space 26 where a width L of an opening 30C opened on the sealed space 26 is wider than the width T of a bending section 23 generated when the elastic membrane 22 is expanded.

Description

  The present invention relates to a grasping device for grasping an object such as a part.

  As a grasping device for grasping an object such as a component, for example, a grasping device described in Patent Document 1 is known. In the gripping device described in Patent Document 1, an annular tube body is disposed inside a cylindrical hard main body portion, and a sealed space formed between the tube body and the inner peripheral surface of the hard main body portion. When the fluid is injected from the injection port penetrating the hard main body, the tube body expands toward the central axis of the hard main body and grips the object on the expansion surface.

Japanese Patent No. 2793545

  By the way, in the grasping device described in Patent Document 1, since the annular tube body is disposed inside the hard main body portion, when the tube body expands, the tube body faces the central axis of the hard main body portion. A plurality of inflated portions (mountain portions) and a plurality of recessed portions (valley portions) between adjacent expanded portions are generated in the circumferential direction. The bent portion (bent portion) forming the valley portion of the elastic film body may abut on the inner peripheral surface of the hard main body portion depending on the expansion amount of the tube body.

  Moreover, the position where the peak part and the valley part of the tube body occur tends to change irregularly every time the tube body is expanded.

Here, when the bent portion forming the valley portion contacts the inner peripheral surface of the hard main body and covers the inlet when the tube body expands, the slight gap between the bent portion and the edge of the inlet Fluid is supplied from the gap to the sealed space, the amount of fluid injected into the sealed space per unit time decreases, and the expansion speed of the tube body decreases (decreases).
On the other hand, when the bent part forming the valley covers the inlet, the amount of fluid discharged from the sealed space per unit time is also reduced, and the contraction speed of the tube body is also slowed (decreased).

  This invention makes it a subject to suppress the fall of the expansion-contraction rate of the elastic film body which expands and shrinks by supply / discharge of a fluid, and grasps a target object by expansion | swelling.

  The gripping device according to claim 1 of the present invention is disposed inside the tubular member and the inside of the tubular member, forms a sealed space between the inner peripheral surface of the tubular member, and the sealed space. An annular elastic film body that expands toward the central axis of the cylindrical member by supplying fluid to the object and holds the object, and is provided in the cylindrical member for fluid circulation to the sealed space, A flow passage having an opening width wider than the width of the bent portion of the elastic film body, which is generated when the elastic film body is expanded.

In the gripping device according to claim 1, the elastic film body is placed in the center of the cylindrical member by supplying fluid to the sealed space through the flow passage in a state where the object is inserted into the hollow portion on the radially inner side of the elastic film body. Grasping the object by expanding (elastically deforming) toward the axis.
Then, the fluid is discharged from the sealed space of the expanded elastic film body through the flow path, so that the elastic film body contracts (restores) to release the object.

  By the way, at the time of expansion of the elastic film body, the elastic film body has a portion (peak portion) that expands toward the central axis of the cylindrical member and a portion (valley portion) that falls between the adjacent expansion portions. There are multiple occurrences. The valley portion of the elastic film body is formed inside (bent inside) the bent portion (hereinafter referred to as “bending portion”) of the elastic film body.

  Here, in the gripping device according to claim 1, the width of the opening that opens in the sealed space of the flow passage is made wider than the width of the bent portion of the elastic film body that is generated when the elastic film body is expanded. For example, the opening of the flow passage is not completely covered by the bent portion of the elastic film body, in other words, the width of the opening is equal to or smaller than the width of the bent portion of the elastic film body. Since a part of the opening of the path protrudes from the range covered with the bent portion, it is possible to suppress a decrease in the flow rate (supply amount and discharge amount) per unit time of the fluid to the sealed space.

  From the above, according to the gripping device according to claim 1, the expansion / contraction rate (expansion rate) of the elastic film body due to the decrease in the flow rate (supply amount and discharge amount) per unit time of the fluid to the sealed space. And a decrease in the contraction speed).

The “width of the bent portion” is the width (length) along the circumferential direction of the cylindrical member in the contact range of the bent portion when the bent portion contacts the inner peripheral surface of the cylindrical member. Among these, the maximum is shown until the expansion of the elastic film body is completed.
The “width of the opening of the flow passage” refers to the width (length) along the circumferential direction of the cylindrical member of the opening of the flow passage.

  The gripping device according to a second aspect of the present invention is the gripping device according to the first aspect, wherein the flow passage is formed in a hollow portion formed on an inner peripheral surface of the cylindrical member and a bottom portion of the hollow portion. And a through hole that opens and penetrates the cylindrical member.

  In the gripping device according to claim 2, since the flow passage is constituted by a hollow portion formed on the inner peripheral surface of the cylindrical member and a through hole opened at the bottom portion of the hollow portion, It is possible to suppress a decrease in the strength of the tubular member due to the through-hole penetrating the tubular member while protruding a part of the opening of the recessed portion which is the opening of the tubular member from the range covered with the bent portion.

  According to a third aspect of the present invention, there is provided a gripping device, wherein the gripping device is disposed inside the tubular member and inside the tubular member, forms a sealed space between the inner peripheral surface of the tubular member, and the sealed space. An annular elastic film body that expands toward the central axis of the cylindrical member by the supply of fluid to the object and grips the object, and is formed in the cylindrical member for fluid flow to the sealed space A through hole and a recess formed on the inner peripheral surface of the cylindrical member and connected to the through hole.

In the gripping device according to claim 3, the elastic film body is provided in the center of the cylindrical member by supplying fluid to the sealed space through the through hole in a state where the object is inserted into the hollow portion on the radially inner side of the elastic film body. Grasping the object by expanding (elastically deforming) toward the axis.
Then, by discharging the fluid from the sealed space of the expanded elastic film body through the through hole, the elastic film body contracts (restores) to release the object.

  Here, in the gripping device according to the third aspect, since the hollow portion connected to the through hole is formed on the inner peripheral surface of the cylindrical member, for example, it is more elastic than that in which the hollow portion is not formed. Even if the through hole is covered by the bent portion of the film body, at least a part of the hollow portion connected to the through hole is opened without being covered by the bent portion. Distribution volume is secured. Thereby, the fall of the distribution | circulation amount (supply amount and discharge | emission amount) per unit time of the fluid with respect to sealed space can be suppressed.

  From the above, according to the grasping device according to claim 3, the expansion / contraction rate (expansion rate) of the elastic film body due to the decrease in the flow rate (supply amount and discharge amount) per unit time of the fluid to the sealed space. And a decrease in the contraction speed).

  The gripping device according to a fourth aspect of the present invention is the gripping device according to the second or third aspect, wherein the hollow portion intersects the central axis along the inner peripheral surface of the cylindrical member. It extends in the direction to do.

  In the gripping device according to the fourth aspect, since the hollow portion extends in a direction intersecting the central axis of the tubular member along the inner peripheral surface of the tubular member, one of the openings of the hollow portion. The portion can be easily protruded from the range covered with the bent portion, and the strength reduction of the tubular member due to the recessed portion can be suppressed.

  The gripping device according to claim 5 is the gripping device according to any one of claims 2 to 4, wherein the depth of the recess is gradually increased toward the end in the extending direction of the recess. It is shallow.

  In the gripping device according to claim 5, since the depth of the dent is gradually made shallower toward the end in the extending direction of the dent, for example, the depth of the dent is made constant. Compared with the thing and the thing which deepened the depth of the hollow part toward the edge part side of the extension direction, the flow of the fluid by the said edge part side of a hollow part can be made smooth.

  The gripping device according to claim 6 is the gripping device according to any one of claims 2 to 5, wherein the hollow portion is orthogonal to the central axis along an inner peripheral surface of the cylindrical member. It extends in the direction to do.

  In the gripping device according to claim 6, since the hollow portion extends in a direction orthogonal to the central axis of the tubular member along the inner peripheral surface of the tubular member, the extending direction of the hollow portion Even if the length of the hollow portion is not excessively long, a part of the opening of the hollow portion can be reliably protruded from the range covered with the bent portion, and the strength reduction of the cylindrical member due to the hollow portion can be effectively reduced. Can be suppressed.

  The gripping device according to claim 7 corresponds to the gripping device according to any one of claims 2 to 6, corresponding to the opening diameter of the bottom portion of the hollow portion of the through hole and the through hole of the bottom portion. The length in the direction orthogonal to the extending direction of the recessed portion of the part is the same.

  In the gripping device according to claim 7, the opening diameter of the bottom portion of the recess portion of the through hole and the length in the direction orthogonal to the extending direction of the recess portion corresponding to the through hole of the bottom portion are the same value. Therefore, for example, the opening diameter of the bottom portion of the recess portion of the through hole is made different from the length in the direction orthogonal to the extending direction of the recess portion corresponding to the through hole of the bottom portion. The flow of fluid from the through hole to the recessed portion and the fluid from the recessed portion to the through hole is smoother than those.

  The gripping device according to an eighth aspect is the gripping device according to the third aspect, wherein the hollow portion makes at least one round of the inner peripheral surface.

  In the gripping device according to claim 8, since the hollow portion makes at least one round of the inner peripheral surface, it is ensured that all the openings of the hollow portion are blocked by the bent portion forming the valley portion of the elastic film body. In addition, since the dent portion makes at least one round of the inner peripheral surface, the fluid from the through hole is allowed to flow regardless of the generation position of the bent portion forming the valley portion of the elastic film body. It can distribute | circulate substantially uniformly to the sealed space through the circumferential direction (circumferential direction of a cylindrical member).

  As described above, the gripping device of the present invention can suppress a decrease in the expansion / contraction speed of the elastic film body that expands and contracts by supplying and discharging fluid and grips the object by expansion.

It is a top view of the grasping device concerning a 1st embodiment of the present invention. It is a side view of the grasping device concerning a 1st embodiment of the present invention. FIG. 3 is a cross-sectional view taken along line 3X-3X in FIG. 1. FIG. 4 is a cross-sectional view taken along line 4X-4X in FIG. 1. FIG. 5 is a sectional view taken along line 5X-5X in FIG. 2. It is a top view of a grasping device showing the state where the elastic membrane object of the grasping device concerning a 1st embodiment of the present invention expanded. It is the 7X-7X sectional view taken on the line of FIG. It is the 8X-8X sectional view taken on the line of FIG. FIG. 9 is an enlarged view of a portion indicated by an arrow 9 </ b> X in FIG. 8. It is a perspective view which shows the supply-and-discharge path periphery of the holding device which concerns on 2nd Embodiment of this invention. It is a top view of the grasping device concerning a 3rd embodiment of the present invention. It is the 12X-12X sectional view taken on the line of FIG.

(First embodiment)
Hereinafter, the gripping device according to the first embodiment of the present invention will be described with reference to FIGS.

  As shown in FIG. 6, the gripping device 10 according to the first embodiment is a device that has a substantially cylindrical shape and grips the gripping object 100 inserted into the hollow portion 11 from the outside. The gripping device 10 is used, for example, as a transfer device that transports the gripping object 100 to another place. Examples of the grasp object 100 include containers such as a bottle and parts such as an OA roller, but other parts (members) may be used.

  As shown in FIG. 1, the gripping device 10 has a cylindrical tubular member 12. The cylindrical member 12 is formed by forming a material harder than an elastic film body 22 described later, for example, a metal material into a cylindrical shape. Note that the cylindrical member 12 may be formed using a resin material as long as sufficient strength can be secured when the gripping device 10 is used.

As shown in FIGS. 3 and 4, the peripheral wall 14 constituting the tubular member 12 has a radially outer side (indicated by an arrow K in FIG. 1) in an intermediate portion in the central axis direction. A flange portion 16 projecting outward) is formed. The flange portion 16 has an annular shape that is continuous in the circumferential direction of the cylindrical member 12 (indicated by an arrow S in FIG. 1). With this configuration, the outer peripheral surface 12A of the tubular member 12 (the peripheral wall 14) has a step shape in the central axis direction. On the other hand, the inner peripheral surface 12B of the cylindrical member 12 (the peripheral wall 14) is flat in the central axis direction.
The “center axis direction” here refers to a direction along the center axis CL of the cylindrical member 12.

  Further, the circumferential wall 14 has groove portions 18 extending along the circumferential direction (circumferential direction of the cylindrical member 12) and surrounding the outer circumferential surface 12A on both sides in the central axis direction with the flange portion 16 of the outer circumferential surface 12A interposed therebetween. A plurality are formed. In the present embodiment, three groove portions 18 are formed on one side in the central axis direction and three on the other side. The groove portion 18 has a curved shape that is continuous from the edge to the bottom of the opening.

  As shown in FIGS. 1 and 3, the peripheral wall 14 has a supply / exhaust passage 20 as an example of a flow passage penetrating from the outer peripheral side to the inner peripheral side of the cylindrical member 12 in a portion where the flange portion 16 is formed. Is provided. The supply / exhaust passage 20 is for circulating fluid (supply / discharge (supply and discharge)) to a sealed space 26 described later. The details of the supply / discharge path 20 will be described later.

  In the present embodiment, air F, which is an example of a fluid, is supplied / exhausted (supply / exhaust) to the sealed space 26 through the supply / discharge path 20. In other embodiments of the present invention, a gas other than air or a liquid may be used as an example of the fluid.

  As shown in FIGS. 3 and 5, the gripping device 10 is disposed inside the cylindrical member 12, specifically, an annular elastic film body 22 disposed along the inner peripheral surface 12 </ b> B. have. The elastic film body 22 is formed, for example, of an elastically deformable material such as rubber in an endless belt shape having a substantially constant thickness, and the endless belt-shaped elastic film body 22 extends along the inner peripheral surface 12B of the cylindrical member 12. After being arranged as described above, both end portions 22A in the width direction of the endless belt are folded back toward the outer peripheral surface 12A side in the vicinity of both end portions 12C in the central axis direction of the cylindrical member 12, and are formed in an annular shape.

  As shown in FIGS. 2 and 3, the folded end portion 22 </ b> A of the elastic film body 22 reaches the side surface of the flange portion 16. In other embodiments of the present invention, the folded back end portion 22A of the elastic film body 22 may be disposed in the vicinity of the side surface without reaching the side surface of the flange portion 16.

  As shown in FIGS. 3 and 4, a caulking ring 24 is disposed on the outer periphery of the folded portion (portion disposed on the outer peripheral surface 12 </ b> A) of the elastic film body 22. The caulking ring 24 is crimped and presses the folded portion of the elastic film body 22 against the peripheral wall 14. The caulking ring 24 fixes the elastic film body 22 to the cylindrical member 12, and a space sealed between the inner peripheral surface 12 B of the cylindrical member 12 and the elastic film body 22 (hereinafter referred to as “sealed space 26”). ”) Is formed.

  In the present embodiment, the caulking ring 24 is disposed at a position where the plurality of groove portions 18 are formed. For this reason, a part of the folded portion of the elastic film body 22 is elastically deformed by the pressing force from the caulking ring 24 and enters the groove portion 18. Thereby, the elastic film body 22 is firmly fixed to the cylindrical member 12, and the sealing performance of the sealed space 26 is improved.

  Here, when air is supplied (supplied) to the sealed space 26 through the supply / discharge path 20, the elastic film body 22 expands (elastically deforms) toward the central axis CL as shown in FIGS. At this time, in the elastic film body 22, a plurality of inflated portions (peak portions 22 </ b> B) and a portion that falls between adjacent peak portions (valley portions 22 </ b> C) are generated in the circumferential direction. The peak portion 22B expands so that the top portion is closest to the central axis CL. In the cross-sectional view shown in FIG. 7, the ridge line indicating the expansion surface 22D has an arc shape, and the cross-sectional view shown in FIG. The ridge line indicating is arcuate. On the other hand, the valley portion 22C is formed inside (bent inside) the bent portion of the elastic film body 22 (hereinafter referred to as “bending portion 23”).

  6 to 8 show a state in which three crests 22B and three troughs 22C are generated in the elastic film body 22, but this state is an example, and the elastic film body 22 has a crest. There may be a case where four (or more) each of the portions 22B and the valleys 22C are generated, or two each.

  Then, air is exhausted from the sealed space 26 of the expanded elastic film body 22 through the supply / exhaust passage 20 so that the elastic film body 22 contracts (elastic deformation is restored), and the elastic film body 22 is moved to the inner peripheral surface 12B. It will be in the state shown in FIGS.

  As shown in FIGS. 4 and 5, the supply / discharge path 20 opens to a groove-like recess 30 formed along the inner peripheral surface 12 </ b> B of the tubular member 12 and a bottom 30 </ b> B of the recess 30. It has a through hole 32 that penetrates the cylindrical member 12 (the peripheral wall 14).

  As shown in FIG. 4, the recess 30 extends in a direction intersecting the central axis CL along the inner peripheral surface 12B. In addition, when the hollow part 30 extends in the direction which cross | intersects with respect to the central axis CL along the internal peripheral surface 12B said here, when the internal peripheral surface 12B is seen, the hollow part 30 is with respect to the central axis direction. In other words, it means that the recess 30 extends in the circumferential direction of the tubular member 12 or in a direction inclined with respect to the circumferential direction.

  In the present embodiment, the recess 30 extends along the inner peripheral surface 12B in a direction orthogonal to the central axis CL, that is, along the circumferential direction of the tubular member 12.

As shown in FIGS. 4 and 5, the through hole 32 extends along the radial direction of the tubular member 12. The through hole 32 is a round hole (see FIG. 2) having a substantially constant inner diameter.
In addition, the through-hole 32 of other embodiment of this invention may be extended in the direction which cross | intersects the radial direction of the cylindrical member 12, and a polygonal shape or an elliptical shape may be sufficient as a hole shape.

  As shown in FIG. 4, the through-hole 32 is disposed in the intermediate portion in the extending direction of the recess 30. In particular, in the present embodiment, the through hole 32 is disposed in the central portion in the extending direction of the recessed portion 30.

  As shown in FIG. 5, the depth D of the recess 30 is gradually shallower toward the end 30 </ b> A side in the extending direction of the recess 30. Specifically, in the present embodiment, the bottom 30B of the recess 30 is continuously curved so that the depth D gradually decreases from the through hole 32 side toward the end 30A.

  As shown in FIG. 4, the length W (that is, the groove width of the recess 30) W in the direction orthogonal to the extending direction of the recess 30 in the portion corresponding to the through hole 32 of the bottom 30 </ b> B of the recess 30. The diameter of the opening (hereinafter simply referred to as the opening diameter) R opening in the bottom 30B of the through hole 32 is the same value. Further, in the plan view, the recessed portion 30 has an end portion 30A having an arc shape, and a width (groove width) of a portion excluding the end portion 30A is substantially constant (the same width on both the bottom portion 30B side and the opening side). Yes. In other embodiments of the present invention, the width (groove width) of the recess 30 may be configured to gradually or intermittently narrow from the through hole 32 side toward the end 30A, and may be smaller than the bottom 30B side. It is good also as a structure widened by the opening side.

  Further, as shown in FIG. 9, the width (length) L along the extending direction of the opening 30 </ b> C of the hollow portion 30 (synonymous with the circumferential direction of the tubular member 12) has a trough 22 </ b> C of the elastic film body 22. Of the width (length) T along the circumferential direction of the cylindrical member 12 in the contact range of the bent portion 23 when the bent portion 23 to be formed contacts the inner peripheral surface 12B of the cylindrical member 12, elastic It is wider than the maximum width Tmax until the film body 22 is completely expanded. In addition, the width L of the opening 30 </ b> C of the hollow portion 30 is the same as the width of the opening of the supply / discharge path 20.

Next, the operation of the gripping device 10 according to the first embodiment of the present invention will be described.
As shown in FIGS. 6 to 8, in the gripping device 10, the air F is supplied (supplied) to the sealed space 26 through the supply / exhaust passage 20 in a state where the gripping object 100 is inserted into the hollow portion 11, thereby being elastic. The film body 22 expands (elastically deforms) toward the central axis CL, and the object 100 is grasped by the expansion surface 22D. Specifically, the grasping object 100 is grasped by pressing the outer periphery of the grasping object 100 from multiple directions with the expansion surface 22D of each mountain portion 22B.

  In the gripping device 10, for example, after the gripping object 100 is transferred to another place by the transfer device, the air F is exhausted (discharged) from the sealed space 26 of the expanded elastic film body 22 through the supply / discharge passage 20. As a result, the elastic film body 22 contracts (restores) to release the grasp object 100.

  Here, in the gripping device 10, the width L of the opening 30 </ b> C opening in the sealed space 26 of the supply / exhaust passage 20 is wider than the width T of the bent portion 23 of the elastic film body 22. The width 30 of the elastic film body 22 is equal to or smaller than the width T of the bent portion 23 of the elastic film body 22, in other words, the opening 30 </ b> C of the supply / discharge path 20 is not completely covered by the bent portion 23 of the elastic film body 22. In addition, since a part of the opening 30 </ b> C of the supply / exhaust passage 20 protrudes from the range covered with the bent portion 23 (the contact range of the bent portion 23), the supply / discharge amount (supply amount) of the air F per unit time with respect to the sealed space 26 And reduction in emissions) are suppressed.

  From the above, according to the gripping device 10, the expansion / contraction speed (expansion speed and contraction) of the elastic film body 22 due to a decrease in the flow rate (supply amount and discharge amount) of the air F per unit time with respect to the sealed space 26. Speed) can be suppressed.

  Further, in the present embodiment, the supply / discharge path 20 is configured by the recess 30 and the through-hole 32 having a substantially constant diameter that opens to the bottom 30B of the recess 30. It is possible to suppress a decrease in strength of the tubular member 12 due to the through hole 32 penetrating the tubular member 12 while protruding a part from the range covered with the bent portion 23.

Further, the valley 22C of the elastic film body 22 is formed so as to extend along the central axis direction. In other words, the bent portion 23 forming the valley 22C is formed so as to extend along the central axis direction. By extending the portion 30 along the inner peripheral surface 12B in a direction intersecting the central axis CL, a part of the opening 30C of the recessed portion 30 can be easily protruded from the range covered by the bent portion 23, and the recessed portion The strength reduction of the cylindrical member 12 due to 30 can be suppressed.
In particular, in this embodiment, since the hollow part 30 is extended in the direction orthogonal to the central axis CL along the inner peripheral surface 12B, the length of the hollow part 30 in the extending direction is not excessively long. Further, a part of the opening 30 </ b> C of the hollow portion 30 can be reliably protruded from the range covered by the bent portion 23, and further, the strength reduction of the cylindrical member 12 caused by the hollow portion 30 can be effectively suppressed. it can.

Further, in the gripping device 10, since the depth D of the recess 30 is gradually made shallower toward the end 30 </ b> A side in the extending direction of the recess 30, for example, the depth D of the recess 30 is reduced. The flow of the air F on the end 30A side of the recess 30 is smoother than that of the constant or the depth D of the recess 30 deepened toward the end 30A in the extending direction. The expansion / contraction speed of the elastic film body 22 is improved (fastened).
In particular, in the present embodiment, since the bottom of the depression 30 is continuously curved so that the depth D gradually decreases from the through hole 32 side toward the end 30A, the air flowing in the depression 30 is obtained. The flow of F becomes smoother.

  Moreover, in the holding apparatus 10, since the width W of the bottom part 30B of the hollow part 30 is set to the same value as the opening diameter R of the through-hole 32, for example, the width W and the opening diameter R are set to different values. In comparison, the distance between the hole wall surface constituting the through-hole 32 and the wall surface (groove wall surface) constituting the recess 30 is shortened, and the through-hole 32 to the recess 30 and the recess 30 to the through-hole 32 are reduced. The flow of air F becomes smooth. Thereby, the expansion / contraction speed of the elastic film body 22 is improved (accelerated).

(Second Embodiment)
Next, a gripping device according to a second embodiment of the present invention will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the same structure as 1st Embodiment, and the description is abbreviate | omitted.

  As shown in FIG. 10, the gripping device 40 of this embodiment has the same configuration as the gripping device 10 of the first embodiment, except for the configuration around the recess 46, the through hole 48, and the recess 46. For this reason, below, only the structure of the hollow part 46, the through-hole 48, and the hollow part 46 periphery is demonstrated.

  On the peripheral wall 14 of the cylindrical member 12 constituting the gripping device 40, a raised portion 44 that protrudes radially inward (synonymous with the central axis CL side) at a portion corresponding to the flange portion 16 at an intermediate portion in the central axis direction. Is formed. With this configuration, the inner peripheral surface 12B of the cylindrical member 12 (the peripheral wall 14) has a step shape in the central axis direction. That is, the top surface of the raised portion 44 constitutes a part of the inner peripheral surface 12B of the tubular member 12.

  Further, the peripheral wall 14 of the cylindrical member 12 is provided with a through hole 48 penetrating from the outer peripheral side to the inner peripheral side of the cylindrical member 12 at a portion where the flange portion 16 and the raised portion 44 are formed. The through hole 48 has a substantially constant hole diameter, and is used for the flow of fluid (air) F to the sealed space 26 (for supply (supply) and discharge (exhaust)).

  A recessed portion 46 connected to the through hole 48 is formed on the inner peripheral surface 12B of the portion corresponding to the raised portion 44 of the tubular member 12. The recess 46 extends in the direction orthogonal to the central axis CL along the inner peripheral surface 12B, and divides the raised portion 44 into one side and the other side in the central axis direction (divided raised portion 44A). 44B). In the present embodiment, the through hole 48 is connected to the bottom 46 </ b> B of the recess 46. Further, the recess 46 has a width W of the bottom 46 </ b> B set to the same value as the opening diameter R of the through hole 48. Note that the width W of the bottom 46 </ b> B of the recess 46 is substantially constant in the extending direction of the recess 46.

Next, the effect of the gripping device 40 of the second embodiment will be described.
In addition, the description about the effect similar to 1st Embodiment among the effects of this embodiment is abbreviate | omitted.

  In the gripping device 40, since the recess 46 is formed so as to divide the raised portion 44 at a portion corresponding to the raised portion 44 of the inner peripheral surface 12B, the bent portion that forms the valley portion 22C of the elastic film body 22 is formed. Even if the opening 47 </ b> A that opens to the top surface of the raised portion 44 is blocked by the opening 23 </ b> C of the recessed portion 46, the opening 47 </ b> B of the recessed portion 46 that opens to both sides of the raised portion 44 is covered by the bent portion 23. Therefore, it is possible to reliably prevent all the openings 46C of the recess 46 from being closed.

  In the gripping device 40 of the second embodiment, as shown in FIG. 10, the bottom 46 </ b> B of the recess 46 reaches the bottom of the raised portion 44, but the present invention is not limited to this configuration, and the raised portion 44 of the raised portion 44. Even if it does not reach the bottom, it may reach a position deeper than the bottom of the raised portion 44 (a position that enters the peripheral wall 14).

(Third embodiment)
Next, a gripping device according to a third embodiment of the present invention will be described with reference to FIGS. In addition, the same code | symbol is attached | subjected to the same structure as 1st Embodiment, and the description is abbreviate | omitted.

  As shown in FIGS. 11 and 12, the gripping device 50 of the present embodiment has the same configuration as the gripping device 10 of the first embodiment, except for the configuration of the recessed portion 54 and the through hole 56. For this reason, below, only the structure of the hollow part 54 and the through-hole 56 is demonstrated.

  A through hole 56 penetrating from the outer peripheral side of the cylindrical member 12 to the inner peripheral side is formed in the peripheral wall 14 of the cylindrical member 12. The through hole 56 has a substantially constant hole diameter, and is used for circulation (supply and discharge) of the fluid (air) F with respect to the sealed space 26.

  On the inner peripheral surface 12 </ b> B of the cylindrical member 12, a recess 54 connected to the through hole 56 is formed. The recessed portion 54 has a groove shape that makes at least one round of the inner peripheral surface 12B. Specifically, the recessed portion 54 continuously extends in a direction orthogonal to the central axis CL (in other words, the circumferential direction of the cylindrical member 12) along the inner peripheral surface 12B. In the present embodiment, the through hole 56 is connected to the bottom 54B of the recess 54. Further, the depth D of the recess 54 is set to be substantially constant, and the width W of the bottom 54B is set to the same value as the opening diameter R of the through hole 56. The width W of the bottom 54B of the recess 54 is substantially constant in the extending direction.

Next, the effect of the gripping device 50 of the third embodiment will be described.
In addition, the description about the effect similar to 1st Embodiment among the effects of this embodiment is abbreviate | omitted.

  In the gripping device 50, since the recessed portion 54 makes a round on the inner peripheral surface 12 </ b> B, it is ensured that all the openings of the recessed portion 54 are blocked by the bent portion 23 that forms the valley portion 22 </ b> C of the elastic film body 22. Can be prevented.

  Regardless of the generation position of the bent portion 23 that forms the valley portion 22C of the elastic film body 22, the air F is substantially uniformly distributed in the circumferential direction (circumferential direction of the tubular member 12) into the sealed space 26 through the recess portion 54. Supply and exhaust can be performed.

  In the third embodiment, the recessed portion 54 continuously extends in the direction orthogonal to the central axis CL along the inner peripheral surface 12B and makes a round around the inner peripheral surface 12B. It is not limited to a structure, The hollow part 54 may be continuously extended in the direction which cross | intersects the central axis CL along the internal peripheral surface 12B, and may make this internal peripheral surface 12B 1 round or more. For example, the recess 54 may be formed in a spiral shape on the inner peripheral surface 12B.

(Other embodiments)
In the first to third embodiments, the supply / exhaust passage 20 provided in the cylindrical member 12 also serves to supply and discharge the fluid (air) F to the sealed space 26, but the present invention is not limited to this configuration. For example, the tubular member 12 may be provided with a supply path for supplying the fluid (air) F to the sealed space 26 and a discharge path for discharging the air F from the sealed space 26.

  In the first to third embodiments, the cylindrical member 12 is cylindrical, but the present invention is not limited to this configuration, and the cylindrical member 12 may be an elliptical cylindrical shape or a polygonal cylindrical shape. . Thus, when the cylindrical member 12 is an elliptical cylindrical shape or a polygonal cylindrical shape, the shape of the elastic film body 22 disposed along the inner peripheral surface 12B of the cylindrical member 12 is also elliptical or It becomes a polygonal ring.

  In the first embodiment, the supply / discharge path 20 is configured by the recess 30 and the through-hole 32, but the present invention is not limited to this configuration, and the supply / discharge path 20 is formed on the outer peripheral side of the cylindrical member 12. It is good also as a through-hole from which the circumferential direction length of the cylindrical member 12 becomes long gradually from inner side to an inner peripheral side, and a distribution area becomes large. Note that the term “gradually longer” as used herein includes those that are continuously longer from the outer peripheral side to the inner peripheral side of the cylindrical member 12 and those that are intermittently longer.

  In the first to third embodiments, the end 22 </ b> A side of the elastic film body 22 is folded back to the outer peripheral surface 12 </ b> A side of the tubular member 12 and fixed by the caulking ring 24, but the present invention is limited to this configuration. It is good also as a structure fixed to the internal peripheral surface 12B of the cylindrical member 12, without folding up the edge part 22A side of the elastic film body 22.

  In all the embodiments described above, the groove portions 30, 46, 54 may have a groove shape branched into a plurality of portions.

  The embodiments of the present invention have been described above with reference to the embodiments. However, these embodiments are merely examples, and various modifications can be made without departing from the scope of the invention. It goes without saying that the scope of rights of the present invention is not limited to these embodiments.

DESCRIPTION OF SYMBOLS 10 Grasp apparatus 12 Cylindrical member 12B Inner peripheral surface 14 Peripheral wall 20 Supply / discharge path (flow path)
22 Elastic membrane body 26 Sealed space 30 Indented portion 30A End portion 30B Bottom portion 32 Through-hole 40 Grab device 42 Feed / discharge path (flow passage)
46 Depression 46B Bottom 48 Through-hole 50 Grab device 52 Supply / exhaust path 54 Depression 54B Bottom 56 Through-hole (flow passage)
100 Grab object (object)
CL Center axis D Depth (depth of dent)
R diameter (opening diameter of supply / discharge hole (flow passage))
W width (width of the portion connected to the supply / exhaust hole (flow passage) of the recess)
L width (opening width of the recess)
T width (width of bent part of elastic film body)

Claims (8)

A tubular member;
It is arranged inside the cylindrical member, forms a sealed space with the inner peripheral surface of the cylindrical member, and expands toward the central axis of the cylindrical member by supplying fluid to the sealed space. An annular elastic membrane body for grasping the object,
Circulation provided in the cylindrical member, for fluid flow to the sealed space, and having a wider opening opening in the sealed space than the width of the bent portion of the elastic film body generated when the elastic film body expands Road,
Having a gripping device.   The said flow path is comprised including the hollow part formed in the internal peripheral surface of the said cylindrical member, and the through-hole which opens to the bottom part of the said hollow part, and penetrates the said cylindrical member. The gripping device as described in. A tubular member;
It is arranged inside the cylindrical member, forms a sealed space with the inner peripheral surface of the cylindrical member, and expands toward the central axis of the cylindrical member by supplying fluid to the sealed space. An annular elastic membrane body for grasping the object,
A through-hole drilled in the tubular member and used for fluid flow to the sealed space;
A recess formed on the inner peripheral surface of the tubular member and connected to the through hole;
Having a gripping device.   4. The gripping device according to claim 2, wherein the hollow portion extends in a direction intersecting the central axis along an inner peripheral surface of the cylindrical member.   The gripping device according to any one of claims 2 to 4, wherein the depth of the recess is gradually shallower toward an end in the extending direction of the recess.   The gripping device according to any one of claims 2 to 5, wherein the hollow portion extends in a direction orthogonal to the central axis along an inner peripheral surface of the cylindrical member.   The opening diameter of the bottom part of the said recessed part of the said through-hole and the length of the direction orthogonal to the extending direction of the said recessed part of the part corresponding to the said through-hole of the said bottom part are the same. The gripping device according to any one of the above.   The gripping device according to claim 3, wherein the hollow portion makes at least one round of the inner peripheral surface of the cylindrical member.

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