Bernoulli gripper

Abstract

A Bernoulli gripper (10) comprises a columnar body (12) and a cover body (14) attached to the body (12). The body (12) has a circumferential edge part (132) that smoothly curves from a recess (130) of a suction part (122) formed at the tip of the body (12) to a side wall (134). The cover body (14) has: a central section (140) positioned at a portion corresponding to the center of the recess (130); and a plurality of branch sections (142) extending in the radial direction (D2) of the body (12) at intervals from the central section (140) and reaching the side wall (134) through the circumferential edge part (132).

Description

Bernoulli Gripper

[0001] The present disclosure relates to a Bernoulli gripper.

[0002] Japanese Patent Application Laid-Open Publication No. 2015-126174 discloses a substrate holding device (Bernoulli gripper) equipped with a chuck portion for holding a substrate. This Bernoulli gripper includes a cylindrical main body (outer chuck portion) and a suction portion (inner chuck portion). The suction portion is formed at the tip of the main body and has a recess in the center. At the tip of the main body, gas is released in the radial direction of the main body, generating negative pressure that attracts the substrate to the suction portion.

[0003] There is a strong demand for a Bernoulli gripper that can hold a workpiece well.

[0004] The present invention aims to solve the above-mentioned problems.

[0005] An aspect of the present disclosure is a Bernoulli gripper comprising: a columnar main body; an adsorption portion formed at the tip of the main body and having a recess in the center; a nozzle that blows air into the recess along a radial direction of the main body; and a cover body attached to the main body so as to cover a portion of the adsorption portion and a portion of a side wall of the main body, wherein the main body has a peripheral portion that curves smoothly from the recess to the side wall, and the cover body has a central portion located at a position corresponding to the center of the recess, and a plurality of branch portions that extend radially from the central portion at intervals from each other and reach the side wall via the peripheral portion.

[0006] According to the above aspect, the workpiece can be held in a good condition.

[0007] The above objects, features and advantages will be easily understood from the following description of the embodiments, which is given with reference to the accompanying drawings.

[0008] FIG. 1 is a perspective view of a Bernoulli gripper according to a first embodiment. FIG. 2 is a side view of the Bernoulli gripper according to the first embodiment. FIG. 3 is a cross-sectional view of the Bernoulli gripper taken along line III-III in FIG. 2. FIG. 4 is a perspective view of a Bernoulli gripper according to a second embodiment. FIG. 5 is a side view of a Bernoulli gripper according to the second embodiment. FIG. 6 is a cross-sectional view of the Bernoulli gripper taken along line VI-VI in FIG. 5. FIG. 7 is a view of the tip side of the Bernoulli gripper viewed along the axial direction. FIG. 8 is a perspective view of a cover body according to a first modification. FIG. 9 is a cross-sectional view of a Bernoulli gripper according to a second modification.

[0009] When a Bernoulli gripper is used to hold one of a number of relatively small workpieces such as semiconductor chips, other workpieces located around the workpiece to be held may be blown away by gas emitted from the tip of the body of the Bernoulli gripper in the radial direction of the body.

[0010] In addition, when a relatively thin workpiece such as a film is held by a Bernoulli gripper, the workpiece may be attracted to the suction portion of the Bernoulli gripper and vibrate due to gas emitted from the tip of the body of the Bernoulli gripper in the radial direction of the body.

[0011] The present disclosure proposes a Bernoulli gripper that solves the above problems.

[0012] First Embodiment Fig. 1 is a perspective view of a Bernoulli gripper 10 according to the first embodiment. Fig. 2 is a side view of the Bernoulli gripper 10 according to the first embodiment. The Bernoulli gripper 10 is a gripper that generates negative pressure by radially ejecting a fluid. The Bernoulli gripper 10 is attached to the tip of a robot arm provided in an automated line in a factory or the like, and is used to grip and transport a workpiece.

[0013] The Bernoulli gripper 10 includes a main body 12 and a cover body 14. The main body 12 is a member that radially ejects air (compressed air) supplied from an air supply device to generate negative pressure. The cover body 14 is a member that covers a portion of the main body 12. The cover body 14 is a member separate from the main body 12 and is attached to the main body 12.

[0014] Fig. 3 is a cross-sectional view of the Bernoulli gripper 10 taken along line III-III in Fig. 2. The main body 12 is formed in a columnar shape. In this embodiment, the main body 12 is formed in a cylindrical shape, but is not limited thereto. For example, the main body 12 may be formed in a polygonal columnar shape such as a hexagonal columnar shape.

[0015] The main body 12 has a detachable part 120, an adsorption part 122, and a flow path member 124. The detachable part 120 is a part that can be attached to and detached from a holder provided at the tip of a robot arm. The detachable part 120 protrudes from a base end surface 126 of the main body 12. The detachable part 120 is formed integrally with the main body 12, but may also be formed separately from the main body 12. When the detachable part 120 is formed separately from the main body 12, it is connected to the main body 12 by, for example, welding or the like.

[0016] The suction portion 122 is a portion used to suction a workpiece. The suction portion 122 is formed at the tip of the main body 12. The suction portion 122 has a gripper surface 128. The gripper surface 128 is an end surface formed at the tip of the main body 12. The gripper surface 128 faces the workpiece. A recess 130 is formed in the center of the suction portion 122 (gripper surface 128). The inner diameter of the recess 130 gradually increases from the base end side toward the tip end side.

[0017] A peripheral edge 132 of the gripper surface 128 is smoothly curved from the recess 130 to the side wall 134 of the main body 12. In other words, the peripheral edge 132 is formed by a curved surface so that the air blown into the recess 130 flows along the gripper surface 128 due to the Coanda effect and further flows along the side wall 134 of the main body 12.

[0018] The flow path member 124 is a member that guides air supplied from the air supply device to the suction part 122. The flow path member 124 is fixed to the main body 12 in a state where it is inserted into a hole 12H of the main body 12. The hole 12H is a hollow portion formed inside the main body 12. The hole 12H is located in the center (axial center) part of the main body 12 and extends in the axial direction D1 of the main body 12.

[0019] The hole portion 12H has a base end side hole HP1, an intermediate hole HP2, and a tip end side hole HP3. The base end side of the base end side hole HP1 opens at the base end of the detachable portion 120, and the tip end side of the base end side hole HP1 is connected to the intermediate hole HP2. The intermediate hole HP2 is located between the base end side hole HP1 and the tip end side hole HP3, and has a thread groove TG1. The thread groove TG1 is formed on the inner circumferential surface of the main body 12 surrounding the hollow portion of the intermediate hole HP2. The base end side of the tip end side hole HP3 is connected to the intermediate hole HP2, and the tip end side of the tip end side hole HP3 opens at the gripper surface 128. The hole diameter of the tip end side hole HP3 is larger than the hole diameters of the base end side hole HP1 and the intermediate hole HP2.

[0020] The flow path member 124 has a rod portion 124A and a flange portion 124B. The rod portion 124A has a thread groove TG2 on its outer surface that can be threaded into the thread groove TG1 of the intermediate hole portion HP2. The flow path member 124 is fixed to the main body 12 by threading the thread groove TG2 of the rod portion 124A into the thread groove TG1 of the intermediate hole portion HP2. When the flow path member 124 is fixed to the main body 12, the base-end hole portion HP1 becomes a supply port 136. A compressed air pipe is connected to the supply port 136.

[0021] The flange portion 124B is connected to the tip of the rod portion 124A. The flange portion 124B widens in the radial direction D2 of the main body 12 as it moves from the base end side to the tip end side. A portion of the flange portion 124B is located in the center of the recess 130. The tip surface of the flange portion 124B extends in the radial direction D2 of the main body 12. A fitting portion 138 into which a portion of the cover body 14 fits is formed on the tip surface of the flange portion 124B. The fitting portion 138 is, for example, a cylindrical hole.

[0022] The flow path member 124 is formed with an axial flow path FP1 and a branch flow path FP2. The axial flow path FP1 and the branch flow path FP2 are located in the rod portion 124A. The base end of the axial flow path FP1 communicates with the supply port 136, and the tip end of the axial flow path FP1 communicates with the branch flow path FP2. The branch flow path FP2 extends in the radial direction D2 of the main body 12 and communicates with the annular flow path FP3.

[0023] An annular flow path FP3 and a nozzle NZ are formed between the flow path member 124 and the main body 12. The annular flow path FP3 is a gap between the inner circumferential surface of the tip-side hole portion HP3 and the outer circumferential surface of the flow path member 124. The annular flow path FP3 extends in an annular shape so as to surround the outer circumferential portion of the flow path member 124.

[0024] The nozzle NZ is a gap between the gripper surface 128 and the outer circumferential surface of the flow path member 124. The nozzle NZ is in communication with the annular flow path FP3 and the recess 130. The opening of the nozzle NZ is located on the side of the flange portion 124B and opens toward the radial direction D2 of the main body 12 (see FIG. 1). The nozzle NZ blows compressed air from the annular flow path FP3 into the recess 130 along the radial direction D2 of the main body 12.

[0025] The cover body 14 is detachable from the main body 12. In this embodiment, the cover body 14 is an elastic body, but it does not have to be an elastic body. The cover body 14 has a central portion 140 and multiple branch portions 142. The central portion 140 is located at a position corresponding to the center of the suction portion 122 (gripper surface 128). A protrusion 144 that protrudes toward the main body 12 is formed on the central portion 140. The protrusion 144 is fitted into the fitting portion 138. The fitting of the protrusion 144 into the fitting portion 138 prevents the cover body 14 from shifting position relative to the main body 12.

[0026] The multiple branches 142 extend from the central portion 140 at intervals in the radial direction D2 of the main body 12, passing through the peripheral edge portion 132 and reaching the side wall 134. Portions of the main body 12 located between the branches 142 are exposed from the cover body 14 without being covered by the cover body 14. The multiple branches 142 are in contact with the peripheral edge portion 132, but they may not be in contact with the peripheral edge portion 132. The multiple branches 142 are not in contact with the flange portion 124B, but may be in contact with the flange portion 124B. The number of branches 142 is six, but is not limited to this. The cross-sectional shape of the branches 142 perpendicular to the direction in which they extend is not particularly limited. For example, the cross-sectional shape of the branches 142 may be circular, polygonal, semicircular, or fillet-shaped. The branches 142 may be hollow or solid.

[0027] The multiple branches 142 are flexible. An engaging portion 146 is formed at the tip of each of the multiple branches 142. The engaging portion 146 protrudes from the branch 142 toward the main body 12. The engaging portion 146 engages with a locking portion 148 formed on the side wall 134 of the main body 12. The elasticity of the branch 142 causes the engaging portion 146 to fit into the locking portion 148 and engage with the locking portion 148. The cover body 14 is attached to the main body 12 by the engagement of the engaging portion 146 with the locking portion 148.

[0028] The Bernoulli gripper 10 of this embodiment is configured as described above. The operation of the Bernoulli gripper 10 will be described below.

[0029] Compressed air is supplied to the Bernoulli gripper 10 through a supply port 136. The compressed air passes through an axial flow path FP1, a branch flow path FP2, and an annular flow path FP3 in this order, and reaches a nozzle NZ. The nozzle NZ blows the compressed air into the recess 130 along the radial direction D2 of the main body 12. At that time, due to Bernoulli's principle, a negative pressure lower than atmospheric pressure is generated in the center of the recess 130.

[0030] The Bernoulli gripper 10 is arranged so that the workpiece faces the gripper surface 128 with air being blown out from the nozzle NZ. As a result, the workpiece is attracted to the suction portion 122 by the negative pressure generated in the center of the recess 130, and is held apart from the gripper surface 128.

[0031] A central portion 140 of the cover body 14 is located at a position corresponding to the center of the recess 130. A plurality of branch portions 142 extend from the central portion 140 at intervals in the radial direction D2 of the main body 12. As a result, the workpiece attracted to the suction portion 122 is supported by contacting the cover body 14. As a result, even when a relatively thin workpiece such as a film is held by the Bernoulli gripper 10, the air blown in the radial direction D2 of the main body 12 can suppress vibration of the workpiece attracted to the suction portion 122.

[0032] The peripheral edge 132 of the main body 12 is smoothly curved from the recess 130 to the side wall 134 of the main body 12. A part of this peripheral edge 132 is located between the branch portions 142 and is not covered by the cover body 14. This allows the flow of air blown out from the nozzle NZ in the radial direction D2 of the main body 12 to be guided by the Coanda effect so as to be rolled up in a direction along the side wall 134 from the radial direction D2. As a result, even when a relatively small workpiece such as a semiconductor chip is held by the Bernoulli gripper 10, other workpieces located around the held workpiece can be prevented from being blown away by the air blown out in the radial direction D2 of the main body 12.

[0033] In this way, the Bernoulli gripper 10 of this embodiment can hold the workpiece well.

[0034] In this embodiment, a protrusion 144 that protrudes toward the main body 12 is formed in the central portion 140 of the cover body 14. Also, a fitting portion 138 into which the protrusion 144 fits is formed in the flange portion 124B of the main body 12 located in the center of the recess 130. This makes it possible to prevent the position of the cover body 14 from shifting relative to the main body 12 due to air blown out from the nozzle NZ, etc.

[0035] Second Embodiment In the second embodiment, components equivalent to those described in the first embodiment are denoted by the same reference numerals. Note that in the second embodiment, descriptions overlapping with those in the first embodiment will be omitted. Fig. 4 is a perspective view of the Bernoulli gripper 10 in the second embodiment. Fig. 5 is a side view of the Bernoulli gripper 10 in the second embodiment.

[0036] The Bernoulli gripper 10 of this embodiment further includes a negative pressure release port 150. The negative pressure release port 150 is opened to the side wall 134 of the main body 12, but is not limited to this. For example, the negative pressure release port 150 may be opened to the base end surface 126 (see FIG. 5 ) of the main body 12. An air pipe is connected to the negative pressure release port 150.

[0037] 6 is a cross-sectional view of the Bernoulli gripper 10 taken along line VI-VI in FIG. 5. The negative pressure release port 150 is in communication with a negative pressure release flow path FP4. The negative pressure release flow path FP4 is a flow path through which air passes to release the negative pressure. The negative pressure release flow path FP4 is formed inside the main body 12, separately from the axial flow path FP1, the branch flow paths FP2, the annular flow path FP3, and the nozzle NZ. One end of the negative pressure release flow path FP4 is in communication with the negative pressure release port 150. The other end of the negative pressure release flow path FP4 opens at the tip surface of the flange portion 124B of the main body 12.

[0038] 7 is a view of the tip side of the Bernoulli gripper 10 along the axial direction D1 (see FIG. 4 ). When viewed in the axial direction, the opening of the negative pressure release flow path FP4 overlaps with the central portion 140 of the cover body 14. In other words, the opening of the negative pressure release flow path FP4 faces toward the central portion 140 of the cover body 14.

[0039] The Bernoulli gripper 10 of this embodiment is configured as described above. The operation of the Bernoulli gripper 10 will be described below.

[0040] Air is supplied to the Bernoulli gripper 10 through the negative pressure release port 150. The air passes through the negative pressure release flow path FP4 and is discharged from the opening of the negative pressure release flow path FP4 to the center of the recess 130. When negative pressure is generated in the center of the recess 130, the air is discharged from the opening of the negative pressure release flow path FP4. The air flows through the gap between the central portion 140 and the gripper surface 128, between the branch portions 142, and into the center of the recess 130. This increases the negative pressure, causing the negative pressure to be broken. As a result, the workpiece is no longer held by the suction portion 122. The opening of the negative pressure release flow path FP4 overlaps with the cover body 14 when viewed in the axial direction. This prevents the air discharged from the opening of the negative pressure release flow path FP4 from directly (excessively) hitting the workpiece to be held. This prevents the air discharged from the opening of the negative pressure release flow path FP4 from blowing away the workpiece to be held. Furthermore, it is possible to prevent other workpieces located around the workpiece to be held from being blown away by the workpiece to be held that has been blown away.

[0041] The opening of the negative pressure release flow path FP4 may be formed so as not to overlap with the cover body 14 when viewed in the axial direction. For example, the opening of the negative pressure release flow path FP4 may be located between the branch portions 142 of the flange portion 124B when viewed in the axial direction. In this case, the time until the negative pressure is released can be shortened. A pressure sensor may also be attached to the negative pressure release port 150. The pressure sensor detects the negative pressure generated in the center of the recess 130. This makes it possible to confirm whether a workpiece is being adsorbed or not, in addition to releasing the negative pressure.

[0042] The above embodiment may be modified as follows.

[0043] Fig. 8 is a perspective view of the cover body 14 in Modification 1. In Fig. 8, the same components as those described above are denoted by the same reference numerals. Note that in this modification, explanations that overlap with those described above will be omitted.

[0044] In this modification, the cover body 14 has a first clamping auxiliary portion 160 and a second clamping auxiliary portion 162 instead of the engaging portion 146 described above.

[0045] The first clamping auxiliary portion 160 extends in a direction along the circumferential direction of the main body 12 and connects two or more branch portions 142. The first clamping auxiliary portion 160 has an abutment surface F160 that abuts against the side wall 134 of the main body 12. The second clamping auxiliary portion 162 extends in a direction along the circumferential direction of the main body 12 and connects two or more branch portions 142 that are not connected by the first clamping auxiliary portion 160. The second clamping auxiliary portion 162 has an abutment surface F162 that abuts against the side wall 134 of the main body 12.

[0046] The first clamping auxiliary part 160 and the second clamping auxiliary part 162 are not connected to each other and are separated from each other. When the cover body 14 is not attached to the main body 12, the first clamping auxiliary part 160 and the second clamping auxiliary part 162 face each other.

[0047] In this modification, the first clamping auxiliary part 160 and the second clamping auxiliary part 162 clamp the side wall 134 of the main body 12 by the elasticity of the branch part 142. This attaches the cover body 14 to the main body 12. Because the first clamping auxiliary part 160 and the second clamping auxiliary part 162 enter the locking part 148 and clamp the side wall 134 of the main body 12, the cover body 14 can be firmly attached to the main body 12.

[0048] In this modification, the cover body 14 does not necessarily have to include the first clamping auxiliary portion 160 and the second clamping auxiliary portion 162. Even in this case, the elasticity of the branch portions 142 allows the multiple branch portions 142 to clamp the side wall 134 of the main body 12.

[0049] Fig. 9 is a cross-sectional view of the Bernoulli gripper 10 according to Modification 2. In Fig. 9, the same components as those described above are denoted by the same reference numerals. Note that in this modification, explanations that overlap with those described above will be omitted.

[0050] In this modified example, the engaging portions 146 are not provided at the tip ends of the plurality of branch portions 142. Also, instead of the locking portions 148, fastening portions 180 are formed to which fastening members 170 can be fastened. The fastening members 170 are bolts or the like, and the fastening portions 180 are screw holes or the like. Also, each of the plurality of branch portions 142 is formed with an insertion hole 190 through which a portion of the fastening member 170 can be inserted.

[0051] In this modification, the fastening members 170 inserted into the insertion holes 190 are fastened to the fastening portions 180, thereby attaching the cover body 14 to the main body 12. Therefore, the cover body 14 can be attached more firmly to the main body 12 than when not fastened by the fastening members 170.

[0052] The following additional notes are further disclosed regarding the above embodiment (including modifications).

[0053] (Supplementary Note 1) A Bernoulli gripper (10) of the present disclosure includes a columnar main body (12), a suction portion (122) formed at the tip of the main body and having a recess (130) in the center, a nozzle (NZ) that blows air into the recess along a radial direction (D2) of the main body, and a cover body (14) attached to the main body so as to cover a part of the suction portion and a part of a side wall (134) of the main body, wherein the main body has a peripheral portion (132) that curves smoothly from the recess to the side wall, and the cover body has a central portion (140) located at a position corresponding to the center of the recess, and a plurality of branch portions (142) that extend from the central portion at intervals from each other in the radial direction and reach the side wall via the peripheral portion.

[0054] (Supplementary Note 2) In the Bernoulli gripper described in Supplementary Note 1, a protrusion (144) protruding toward the main body may be formed in the central portion, and a fitting portion (138) into which the protrusion fits may be formed in the main body.

[0055] (Supplementary Note 3) The Bernoulli gripper according to Supplementary Note 1 may further include a negative pressure breaking port (150) for supplying air to the suction portion through a flow path (FP4) formed in the main body separately from the nozzle.

[0056] (Supplementary Note 4) In the Bernoulli gripper according to Supplementary Note 1, the cover body may be an elastic body.

[0057] (Supplementary Note 5) In the Bernoulli gripper according to Supplementary Note 1, the cover body may be detachable.

[0058] (Supplementary Note 6) In the Bernoulli gripper according to Supplementary Note 1, the cover body may be attached to the main body by elasticity of the branch portions.

[0059] Although the present disclosure has been described in detail, the present disclosure is not limited to the individual embodiments described above. Various additions, substitutions, modifications, partial deletions, etc. are possible in these embodiments without departing from the gist of the present disclosure or the spirit of the present disclosure derived from the content of the claims and their equivalents. These embodiments can also be implemented in combination. For example, in the above-described embodiments, the order of each operation and the order of each process are shown as examples and are not limited to these. The same applies when numerical values ​​or mathematical expressions are used in the description of the above-described embodiments.

Claims

1. A Bernoulli gripper (10) comprising: a columnar main body (12); a suction portion (122) formed at the tip of the main body and having a recess (130) at the center; a nozzle (NZ) that blows air into the recess along the radial direction (D2) of the main body; and a cover body (14) attached to the main body so as to cover a part of the suction portion and a part of the side wall (134) of the main body. The main body has a peripheral edge portion (132) that smoothly curves from the recess to the side wall. The cover body has a central portion (140) located at a position corresponding to the center of the recess, and a plurality of branch portions (142) that extend in the radial direction at intervals from the central portion, pass through the peripheral edge portion, and reach the side wall.

2. The Bernoulli gripper according to claim 1, wherein a protrusion (144) protruding toward the main body is formed in the central portion, and a fitting portion (138) into which the protrusion fits is formed in the main body.

3. The Bernoulli gripper according to claim 1, further comprising a negative pressure breaking port (150) for supplying air to the suction portion through a flow path (FP4) formed in the main body separately from the nozzle.

4. The Bernoulli gripper according to claim 1, wherein the cover body is an elastic body.

5. The Bernoulli gripper according to claim 1, wherein the cover body is detachable.

6. The Bernoulli gripper according to claim 1, wherein the cover body is attached to the main body by the elasticity of the branch portions.

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