Suction pad

Abstract

A suction pad (10) comprises: a body (12) having a negative pressure chamber (20); and a sponge part (14) that is attached to an attachment surface (19) of the body and comes into contact with an object (W) to be suctioned. A plurality of connection holes (18a) for connecting the negative pressure chamber and the exterior are formed in the attachment surface. The sponge part contains a material having semi-open / semi-closed cells. One suction hole (26) connected to the plurality of connection holes, and an edge portion (28) surrounding the suction hole are formed in the sponge part. The height (H1) of the edge portion in the suction direction is longer than the height difference (H2) of the surface of the object to be suctioned.

Description

Suction Pad

[0001] The present disclosure relates to a suction pad that sucks a workpiece using vacuum pressure.

[0002] Japanese Unexamined Patent Publication No. 2024-83701 discloses a suction pad that sucks a workpiece by forming a plurality of cavities communicating with a negative pressure chamber in a sponge and bringing the sponge into contact with the workpiece. The workpiece is lifted using this suction pad and conveyed to a predetermined position.

[0003] The suction pad described in Japanese Unexamined Patent Publication No. 2024-83701 has a problem that the workpiece cannot be lifted when the workpiece is easily deformable and prone to wrinkling, such as a plastic bag or a paper bag.

[0004] An object of the present disclosure is to solve the above-mentioned problem.

[0005] An aspect of the present disclosure is a suction pad comprising: a body having a negative pressure chamber; and a sponge part attached to a mounting surface of the body and brought into contact with an object to be sucked, wherein a plurality of communication holes for communicating the negative pressure chamber with the outside are formed in the mounting surface, the sponge part includes a material having semi-open semi-closed cells, one suction hole communicating with the plurality of communication holes and an edge portion surrounding the suction hole are formed in the sponge part, and a height of the edge portion in a suction direction is longer than a height difference of a surface of the object to be sucked.

[0006] According to the present disclosure, even when a workpiece is easily deformable and prone to wrinkling, such as a plastic bag or a paper bag, the workpiece can be stably sucked.

[0007] Figure 1 is a perspective view of the suction pad according to the embodiment. Figure 2 is an exploded perspective view of the suction pad according to the embodiment. Figure 3 is a cross-sectional view of the suction pad shown in Figure 1, taken along the line III-III. Figure 4 is a rear view of the suction pad taken from below, showing the state in which the sponge portion is tilted inward when a workpiece is adsorbed. Figure 5 is a cross-sectional view of the suction pad shown in Figure 4, taken along the line V-V. Figure 6 is a cross-sectional view of the suction pad in Modification 2. Figure 7 is a rear view of the suction pad in Modification 3 taken from below. Figure 8 is an exploded perspective view of the suction pad in Modification 4. Figure 9 is a cross-sectional view of the suction pad shown in Figure 8, taken along the line IX-IX.

[0008] <Embodiment> Figure 1 is a perspective view of the suction pad 10 of the embodiment, and Figure 2 is an exploded perspective view of the suction pad 10 of the embodiment. Figure 3 is a cross-sectional view of the suction pad 10 shown in Figure 1, taken along the line III-III. In Figure 3, the workpiece W, which is the object to be adsorbed, is shown. The suction pad 10 comprises a body 12 and a sponge portion 14, which is a type of porous material. In the following description, when terms relating to the vertical direction are used, they refer to the direction on the drawing and do not limit the actual arrangement.

[0009] The body 12 has a box-shaped base plate (body) 16 that opens downwards and a suction plate 18 that covers the base plate 16 from below. A negative pressure chamber 20 is formed by the base plate 16 and the suction plate 18. A suction port 24 for connecting the vacuum source 22 and the negative pressure chamber 20 is formed on the upper surface of the base plate 16. Multiple communication holes 18a are formed in the suction plate 18 to connect the negative pressure chamber 20 to the outside. In this embodiment, a vacuum ejector is used as the vacuum source 22, but a vacuum pump may also be used. Figures 1 and 3 illustrate the vacuum source 22, which is a vacuum ejector attached to the suction pad 10.

[0010] The sponge portion 14 is attached to the lower surface (mounting surface) 19 of the suction plate 18. The sponge portion 14 is made of a material having a mixture of closed and open cells. The sponge portion 14 has a plurality of sponge members 14a. The plurality of sponge members 14a are stacked along the suction direction (vertical direction). In this embodiment, four sponge members 14a are stacked. These sponge members 14a are connected to each other by an adhesive such as a double-sided adhesive sheet. The sponge portion 14 (sponge members 14a) is manufactured, for example, by foam molding EPDM (ethylene propylene rubber).

[0011] The sponge portion 14 has one suction hole 26 that communicates with a plurality of communication holes 18a formed in the suction plate 18, and an edge portion 28 that surrounds the suction hole 26. In other words, when the suction pad 10 is viewed from below, the plurality of communication holes 18a formed in the suction plate 18 can be seen through the suction hole 26 (see Figure 3). In this embodiment, the suction hole 26 is rectangular, specifically rectangular. The suction hole 26 may also be circular, elliptical, or polygonal, such as a triangular, pentagonal, or hexagonal hole.

[0012] In this embodiment, a plurality of communication holes 18a are arranged inside the suction hole 26, but a portion of the plurality of communication holes 18a may be arranged to overlap with the edge portion 28. In this case, it is preferable that the number of communication holes 18a that overlap with the edge portion 28 is less than the number of communication holes 18a located inside the suction hole 26, because the communication holes 18a located inside the suction hole 26 contribute to the suction of the workpiece W.

[0013] The vertical height H1 of the sponge portion 14 is greater than the height difference H2 of the surface of the workpiece W. The surface of the workpiece W refers to the surface of the workpiece W that is adsorbed by the suction pad 10. Examples of workpiece W include paper bags and plastic bags that are prone to wrinkling. These paper bags and plastic bags contain granular or powdered materials such as rice and flour, or liquids such as water. When such workpieces W that are prone to changing shape are stacked, the height difference H2 of the surface of the workpiece W to be adsorbed on top becomes even larger, making the workpiece W even more prone to wrinkling. Such workpieces W tend to be heavy under gravity, and a suction pad 10 that exhibits strong suction force is required. For example, the vertical height H1 of the sponge portion 14 is preferably 80 mm to 120 mm, although this depends on the weight of the workpiece W and the height difference H2 of the surface. In this embodiment, since the sponge portion 14 is made up of four stacked sponge members 14a, the vertical height of each sponge member 14a is 20 mm to 30 mm.

[0014] Here, a sponge made of a material with closed cells has high airtightness but does not easily conform to the surface of the workpiece W. Higher airtightness results in higher adsorption force, but if it does not easily conform to the surface of the workpiece W, a small gap is created between the workpiece W and the sponge, reducing the adsorption force. On the other hand, a sponge made of a material with open cells easily conforms to the surface of the workpiece W but also has low airtightness. Increasing airtightness reduces conformability to the workpiece W. Therefore, in order to balance both airtightness and conformability, in this embodiment, the sponge portion 14 (multiple sponge members 14a) is made of a material with semi-closed and semi-open cells.

[0015] According to the suction pad 10 of this embodiment, even when stacking 25 kg paper bags filled with powder (hereinafter referred to as "experimental workpieces"), the experimental workpieces could be effectively adsorbed and lifted.

[0016] On the other hand, when an experimental workpiece was adsorbed using an adsorption pad with multiple cavities in a sponge, as described in Japanese Patent Publication No. 2024-83701, the experimental workpiece could not be stably adsorbed, and it was not possible to lift the workpiece, or if it was lifted, it would fall immediately. In this case, the result was the same regardless of whether the sponge was made of closed-cell, open-cell, or semi-closed-cell material.

[0017] As described above, one adsorption hole 26 is formed in the sponge portion 14 of the material having semi-closed and semi-closed cells, and the height (length) H1 of the sponge portion 14 in the adsorption direction is made greater than the height difference H2 of the surface of the workpiece W. As a result, even if the workpiece W is a plastic bag, paper bag, or other material that is prone to changing shape and wrinkles, the workpiece W can be stably adsorbed.

[0018] The above embodiment can also be modified as follows.

[0019] <Modification 1> In the above embodiment, since the height H1 of the sponge portion 14 is increased, when the sponge portion 14 is compressed and adsorbs the workpiece W, there is a possibility that the edge portion 28 that comes into contact with the atmosphere will tilt inward, that is, that it will tilt toward the adsorption hole 26. As shown in Figures 4 and 5, when the edge portion 28 of the sponge portion 14 tilts significantly inward when the workpiece W is adsorbed, the adhesion of the sponge portion 14 (edge ​​portion 28) to the workpiece W decreases at that point. As a result, a gap is created between the sponge portion 14 (edge ​​portion 28) and the workpiece W, the adsorption hole 26 comes into contact with the atmosphere, and the adsorption force decreases. Also, when the edge portion 28 of the sponge portion 14 tilts significantly inward, the area of ​​the adsorption hole 26 becomes smaller (see Figure 4), and the adsorption force decreases. When the negative pressure P generated in the adsorption hole 26 is the area S of the adsorption hole 26, the adsorption force is expressed as P × S.

[0020] Therefore, in this modified example 1, the sponge member 14a closest to the body 12 (adsorption plate 18) is made of a sponge that is less elastically deformable than the sponge member 14a furthest from the body 12 (adsorption plate 18). Alternatively, the sponge member 14a closer to the body 12 may be made of a sponge that is less elastically deformable. For example, the resistance to elastic deformation of this sponge member 14a can be changed by the ratio of closed cells to open cells. For example, if the ratio of closed cells is higher than the ratio of open cells, the sponge member 14a will be less elastically deformable. Conversely, if the ratio of closed cells is lower than the ratio of open cells, the sponge member 14a will be more elastically deformable. In this embodiment, the sponge member 14a closest to the body 12 and the second closest sponge member 14a are made of a material having only closed cells that are less elastically deformable, while the sponge member 14a furthest from the body 12 and the second furthest sponge member 14a are made of a material having semi-closed and semi-closed cells that are easily elastically deformable.

[0021] This configuration increases the rigidity of the base portion of the sponge portion 14 (edge ​​portion 28), thereby suppressing the inward tilting of the edge portion 28. Furthermore, by lowering the rigidity of the tip portion of the sponge portion 14 (edge ​​portion 28), the tip portion deforms to conform to the surface of the workpiece W, thus ensuring good adhesion of the tip portion of the sponge portion 14 (edge ​​portion 28) to the surface of the workpiece W.

[0022] <Modification 2> In Modification 2, a resin plate 30 is provided between two adjacent sponge members 14a to suppress the inward tilting of the sponge portion 14 (edge ​​portion 28).

[0023] Figure 6 is a cross-sectional view of the suction pad 10 in modified example 2. As shown in Figure 6, resin plates 30 are provided between the first sponge member 14a and the second sponge member 14a, between the second sponge member 14a and the third sponge member 14a, and between the third sponge member 14a and the fourth sponge member 14a, counting from the body 12. Flexible material is used for these resin plates 30. Due to the presence of these resin plates 30, the sponge portion 14 deforms under vertical stress, but is less susceptible to deformation under planar stress. By providing resin plates 30 between two adjacent sponge members 14a, it is possible to suppress the inward tilting of the edge portion 28. Through holes are formed in these resin plates 30 so as not to block the suction holes 26.

[0024] Furthermore, resin plates 30 can be provided between the first sponge member 14a and the second sponge member 14a, and between the second sponge member 14a and the third sponge member 14a, counting from the body 12, but it is not necessary to provide a resin plate 30 between the third sponge member 14a and the fourth sponge member 14a. This makes it possible to suppress the inward tilting of the base portion of the sponge part 14 (edge ​​portion 28) and ensure that the tip portion of the sponge part 14 (edge ​​portion 28) adheres to the surface of the workpiece W. In other words, from the viewpoint of suppressing the inward tilting of the sponge part 14 (edge ​​portion 28), it is sufficient to provide the resin plate 30 at a position close to the body 12.

[0025] <Modification 3> In Modification 3, when the sponge portion 14 is viewed from the adsorption direction, at least one surface of the inner surface 29 of the edge portion 28 that forms the adsorption holes 26 is indented in an arch shape in the thickness direction of the edge portion 28, thereby suppressing the inward tilting of the sponge portion 14 (edge ​​portion 28).

[0026] Figure 7 is a rear view of the suction pad 10 in modified example 3, viewed from below. In Figure 7, two long sides 29a and 29b of the rectangular suction hole 26 on the inner surface 29 are arch-shaped indentations in the thickness direction of the edge 28. In other words, arch-shaped recesses 32 are provided on the two long sides 29a and 29b of the suction hole 26. The two sides 29a and 29b on which the recesses 32 are provided face each other. The reason for providing arch-shaped recesses 32 on the two long sides 29a and 29b is that the long sides 29a and 29b tend to be inclined with respect to the short sides 29c and 29d. Therefore, arch-shaped recesses 32 may also be provided on the short sides 29c and 29d.

[0027] In this embodiment, the suction hole 26 is rectangular in shape, but even if the suction hole 26 is polygonal, an arch-shaped recess 32 may be similarly provided on the inner surface 29 of the edge portion 28.

[0028] <Modification 4> In Modification 4, the body 12 (suction plate 18) is provided with a protruding portion 34 to prevent the edge portion 28 from collapsing, thereby suppressing the inward tilting of the sponge portion 14 (edge ​​portion 28).

[0029] Figure 8 is an exploded perspective view of the suction pad 10 in modified example 4. Figure 9 is a cross-sectional view of the suction pad 10 shown in Figure 8, taken along the line IX-IX. The protruding portion (projection, rib) 34 protrudes downward from the mounting surface 19, which is the lower surface of the body 12 (suction plate 18). The protruding portion 34 is positioned inside the suction hole 26. The protruding portion 34 is formed along the edge 28. Since the protruding portion 34 prevents the edge 28 from tilting inward, it is preferable that the distance between the protruding portion 34 and the inner surface 29 of the edge 28 be short. It is more preferable that the protruding portion 34 and the inner surface 29 are in contact.

[0030] In this modified example 4, the protrusion 34 is formed in an annular shape along the edge 28. If the suction hole 26 is rectangular, the protrusion 34 may be provided only along the two long sides 29a and 29b of the inner surface 29. In this case, the protrusion 34 is not provided along the two short sides 29c and 29d of the inner surface 29. Even in this case, the inward tilting of the sponge portion 14 (edge ​​28) is suppressed.

[0031] The amount of protrusion (projection amount, height) of the protrusion 34 depends on the vertical height of the edge 28, but it needs to be a length (height) that can suppress the inward inclination of the edge 28. On the other hand, if the amount of protrusion of the protrusion 34 is too long (too high), the sponge portion 14 cannot follow the surface of the workpiece W, and the suction force decreases. For this reason, the amount of protrusion of the protrusion 34 should be determined according to the height difference H2 of the surface of the workpiece W. In this modified example 4, it is necessary to set the vertical height H1 of the sponge portion 14 such that the height H3 from the tip (lower end) of the protrusion 34 to the tip (lower end) of the sponge portion 14 is longer than the height difference H2 of the surface of the workpiece W.

[0032] <Modification 5> You may combine any of the embodiments of Modifications 1 to 4 described above.

[0033] The following additional information is disclosed regarding the above embodiments and modifications.

[0034] (Note 1) The suction pad (10) of the present disclosure comprises a body (12) having a negative pressure chamber (20), and a sponge portion (14) attached to a mounting surface (19) of the body and in contact with an object to be adsorbed (W), wherein the mounting surface has a plurality of communication holes (18a) for connecting the negative pressure chamber to the outside, the sponge portion contains a material having semi-closed and semi-closed cells, the sponge portion has one suction hole (26) that communicates with the plurality of communication holes and an edge portion (28) surrounding the suction hole, and the height (H1) of the edge portion in the suction direction is longer than the height difference (H2) of the surface of the object to be adsorbed. As a result, even if the workpiece is a plastic bag, paper bag, or something similar that is prone to changing shape and wrinkles, the workpiece can be stably adsorbed.

[0035] (Note 2) In the suction pad described in Note 1, the sponge portion may be formed by stacking a plurality of sponge members (14a) along the suction direction.

[0036] (Note 3) The suction pad described in Note 2 may include a resin plate (30) provided between two adjacent sponge members. This prevents the edges from tilting inward, that is, from tilting toward the suction holes.

[0037] (Note 4) In the suction pad described in Note 2 or 3, the sponge member closest to the body may be less elastically deformable than the sponge member furthest from the body. This makes it possible to suppress the edge from tilting inward, that is, the edge from collapsing toward the suction hole.

[0038] (Note 5) In the suction pad described in Note 4, the sponge member closest to the body may be made of a material having closed cells, and the sponge member furthest from the body may be made of a material having semi-closed and semi-closed cells. This makes it possible to suppress the edge from tilting inward, that is, the edge from collapsing toward the suction hole.

[0039] (Note 6) The suction pad described in any one of Notes 1 to 5, wherein the suction holes are polygonal in shape, and when the sponge portion is viewed from the suction direction, at least one surface of the inner surface (29) of the edge portion forming the suction holes may be indented in an arch shape in the thickness direction of the edge portion. This makes it possible to suppress the edge portion from tilting inward, that is, from tilting toward the suction holes.

[0040] (Note 7) The suction pad described in any one of Notes 1 to 6 is provided with a projection (34) on the inside of the suction hole to prevent the edge from collapsing, and the projection may protrude from the mounting surface and be formed along the edge. This makes it possible to suppress the edge from tilting inward, that is, from collapsing toward the suction hole.

[0041] While this disclosure has been described in detail, it is not limited to the individual embodiments and variations described above. These embodiments and variations can be added, replaced, modified, partially deleted, etc., in any way that does not depart from the gist of this disclosure or from the intent of this disclosure derived from the claims and their equivalents. These embodiments and variations can also be implemented in combination. For example, the order of operations and processes in the embodiments and variations described above are given as examples only and are not limited thereto. The same applies when numerical values ​​or mathematical formulas are used in the description of the embodiments and variations described above.

[0042] 10...Suction pad 12...Body 14...Sponge part 14a...Sponge component 16...Base plate 18...Suction plate 18a...Communication hole 19...Mounting surface 20...Negative pressure chamber 22...Vacuum generation source 24...Suction port 26...Suction hole 28...Edge 29...Inner surface 29a-29d...Surface 30...Resin plate 32...Recess 34...Protrusion

Claims

1. An adsorption pad (10) comprising: a body (12) having a negative pressure chamber (20); and a sponge portion (14) attached to a mounting surface (19) of the body and in contact with an object to be adsorbed (W), wherein the mounting surface has a plurality of communication holes (18a) for connecting the negative pressure chamber to the outside; the sponge portion contains a material having semi-closed and semi-closed cells; the sponge portion has one adsorption hole (26) communicating with the plurality of communication holes and an edge portion (28) surrounding the adsorption hole; and the height (H1) of the edge portion in the adsorption direction is longer than the height difference (H2) of the surface of the object to be adsorbed.

2. The suction pad according to claim 1, wherein the sponge portion is formed by stacking a plurality of sponge members (14a) along the suction direction.

3. The suction pad according to claim 2, comprising a resin plate (30) provided between two adjacent sponge members.

4. The suction pad according to claim 2, wherein the sponge member closest to the body is less elastically deformable than the sponge member furthest from the body.

5. The suction pad according to claim 4, wherein the sponge member closest to the body is made of a material having closed cells, and the sponge member furthest from the body is made of a material having semi-closed and semi-closed cells.

6. An adhesive pad according to any one of claims 1 to 5, wherein the adhesive holes are polygonal in shape, and when the sponge portion is viewed from the adhesive direction, at least one surface of the inner surface (29) of the edge portion forming the adhesive holes is arch-shaped indented in the thickness direction of the edge portion.

7. A suction pad according to any one of claims 1 to 5, wherein a projection (34) for preventing the edge from collapsing is provided inside the suction hole, and the projection protrudes from the mounting surface and is formed along the edge.

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