Work transfer hand

Abstract

To provide a work transfer hand that enables stable selection of the amount of protrusion of a suction portion from a hand.SOLUTION: In a work transfer hand A1 provided with a support plate 10 and a plurality of suction portions 100 provided so as to face the upper surface of the support plate 10, the support plate 10 includes a lifting body 20 having a recess 12 recessed from the upper surface thereof, a first pressure port 122 and a second pressure port 123 provided at the bottom of the recess 12, and a suction hole 221 penetrating in the vertical thickness direction, an elastic body 30 that urges the lifting body to one side, a first cylindrical member 41 that is connected to the recess 12 such that the lower end surrounds the first pressure port and can expand and contract in the vertical direction, and a second cylindrical member 42 in which the upper end is connected to the lower surface of the lifting body and the lower end is connected to the recess so as to surround the second pressure port between the lifting body and the bottom of the recess, and elastically expands and contracts in the vertical direction.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a work transfer hand used in a transfer device for plate-shaped workpieces such as substrates.

Background Art

[0002] In general, a transfer device for thin plate-shaped workpieces such as glass substrates used in the manufacture of liquid crystal displays and semiconductor wafers used in the manufacture of semiconductors is configured by providing a hand with a suction function using negative pressure as an end effector of a robot. For example, as shown in Patent Document 1, the hand is provided with a plurality of suction pads that can select a state in which negative pressure acts and a state in which negative pressure does not act so as to face the upper surface of the hand as a configuration that bears the suction function. The plate-shaped workpiece placed on the hand is closely held by the suction pad by the negative pressure applied to the suction pad, and in this state, it can be transported at high speed without slipping off the hand.

[0003] Such a transfer device for plate-shaped workpieces is used when taking out a plate-shaped workpiece stored in a cassette and delivering it to a processing device, or receiving a plate-shaped workpiece from a processing device and storing it in a cassette. When taking out a plate-shaped workpiece in a cassette, insert the hand below the plate-shaped workpiece to be taken out with the negative pressure of the suction pad released, raise the hand, place the plate-shaped workpiece on this hand, apply negative pressure to the suction pad to closely hold the plate-shaped workpiece, and pull the hand out of the cassette. When storing a plate-shaped workpiece in a cassette, insert the hand with the negative pressure applied to the suction pad to closely hold the plate-shaped workpiece into the cassette, release the negative pressure of the suction pad to make the hand in a simple placement state of the plate-shaped workpiece, lower the hand to transfer the plate-shaped workpiece to the shelf part of the cassette, and pull the hand out of the cassette.

[0004] By the way, in recent years, the size of plate-shaped workpieces has been increasing, and the amount of deflection of the plate-shaped workpieces stored in the cassette tends to increase. In addition, for example, when it is necessary to transfer plate-shaped workpieces of different specifications with different thicknesses to or from the processing apparatus through the storage state in the cassette, in this case, the amounts of deflection of the plurality of plate-shaped workpieces stored in the cassette may vary.

[0005] On the other hand, for the cassette, it is required to increase the processing efficiency by reducing the vertical interval between the stored plate-shaped workpieces and enabling storage of as many plate-shaped workpieces as possible.

[0006] Patent Document 1 discloses a configuration in which the protruding amount of the suction pad with respect to the hand can be changed, and by reducing the protruding amount of the suction pad, even when the vertical interval between the plate-shaped workpieces in the cassette is small, the hand can be inserted while avoiding interference with other plate-shaped workpieces, and the transfer of the plate-shaped workpiece can be enabled by increasing the protruding amount of the suction pad as needed.

[0007] More specifically, what is disclosed in Patent Document 1 has a configuration in which inner and outer double downward-expanding annular leg portions that can be elastically deformed are provided on the lower surface of the suction pad, a first negative pressure path for performing a suction action is connected inside the inner annular leg portion, and a second negative pressure path is connected to the annular space between the inner annular leg portion and the outer annular leg portion. In this configuration, when no negative pressure acts on the first and second negative pressure paths, the suction pad is positioned at a high position and the protruding amount becomes large due to the elasticity of the inner and outer annular leg portions, and the suction pad is positioned at a low position and the protruding amount becomes small by applying negative pressure to the second negative pressure path. Then, by applying negative pressure to the first negative pressure path, the plate-shaped workpiece can be suction-held by applying negative pressure to the upper surface of the suction pad whether the suction pad is at a high position or a low position.

[0008] However, in the configuration disclosed in Patent Document 1, the member (inner and outer double annular leg portions) that constantly biases the suction pad upward also serves as a member that forms an annular space communicating with the second negative pressure path and a space for applying negative pressure to the upper surface of the suction pad. Therefore, there is a problem that the protrusion amount of the suction pad is not stable when negative pressure is applied to the first negative pressure path to closely hold the plate-shaped workpiece.

Prior Art Documents

Patent Documents

[0009]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0010] The present invention has been conceived under such circumstances, and the main problem is to provide a workpiece transfer hand that can stably select the protrusion amount of the suction part from the hand.

Means for Solving the Problems

[0011] In order to solve the above problems, the present invention employs the following technical means.

[0012] The work transfer hand provided by the present invention is a work transfer hand including a support plate and a plurality of suction parts provided so as to face the upper surface of the support plate. The support plate has a recess recessed from its upper surface, and a first pressure port and a second pressure port are provided at the bottom of the recess. The suction part includes a lifting body that is guided to be able to move up and down with a predetermined stroke distance in the recess and has a suction hole penetrating in the vertical thickness direction, an elastic body that always biases the lifting body upward or downward, a first cylindrical member that is connected to the lower surface of the lifting body so that its upper end surrounds the suction hole and is connected to the bottom so that its lower end surrounds the first pressure port and is vertically stretchable, and a second cylindrical member that is connected to the lower surface of the lifting body and is connected to the bottom so that its lower end surrounds the second pressure port and is elastically stretchable in the vertical direction.

[0013] In a preferred embodiment, the first cylindrical member and the second cylindrical member are bellows-shaped.

[0014] In a preferred embodiment, the elastic body always biases the lifting body upward, the first pressure port communicates with a negative pressure source via a first on-off valve, and the second pressure port communicates with an additional negative pressure source via a second on-off valve.

[0015] In a preferred embodiment, the elastic body always biases the lifting body downward, the first pressure port communicates with a negative pressure source via a first on-off valve, and the second pressure port communicates with a positive pressure source via a second on-off valve.

[0016] In a preferred embodiment, an adsorbent that expands in a trumpet shape upward and is elastically deformable is provided on the upper surface of the lifting body.

Advantages of the Invention

[0017] In the above-described workpiece transfer hand, the elastic body constantly biases the lifting body upward. When the first pressure port and the second pressure port are connected to different negative pressure sources, when no negative pressure is applied to the second pressure port, the lifting body assumes the upward position due to the action of the elastic body, and the protrusion amount from the support plate increases. On the other hand, when negative pressure is applied to the second pressure port, the lifting body moves downward against the elastic force of the elastic body to assume the downward position, and the protrusion amount with respect to the support plate decreases. Whether the lifting body assumes the upward position or the downward position, by applying negative pressure to the first pressure port, the plate-shaped workpiece can be adsorbed and held by the lifting body on which negative pressure acts on the suction holes. This means that the protrusion amount of the lifting body with respect to the support plate can be changed, and the plate-shaped workpiece can be adsorbed and held regardless of the protrusion amount of the lifting body.

[0018] Therefore, even when the vertical interval of the plate-shaped workpieces stored in or to be stored in the cassette becomes smaller due to the deflection of the plate-shaped workpieces or the difference in the deflection amounts of the plate-shaped workpieces adjacent vertically, by performing operations such as reducing the protrusion amount of the lifting body when inserting or pulling out the hand to the cassette, the plate-shaped workpieces can be properly transferred to and from the cassette.

[0019] Further, in the above-described workpiece transfer hand, a configuration (elastic body) for constantly biasing the lifting body in the vertical direction is provided separately from the configuration (first cylindrical member) for applying negative pressure to the suction holes regardless of the vertical position of the lifting body. Therefore, the vertical position of the lifting body when adsorbing and holding the plate-shaped workpiece by applying negative pressure to the suction holes can be stabilized.

Brief Description of the Drawings

[0020]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Best Mode for Carrying Out the Invention

[0021] Hereinafter, preferred embodiments of the present invention will be specifically described with reference to the drawings.

[0022] FIGS. 1 to 3 show an example of a work transfer hand according to the present invention. The work transfer hand A1 of the present embodiment is configured by providing a plurality of suction portions 100 so as to face the upper surface of the support plate 10.

[0023] In the present embodiment, the support plate 10 extends integrally in the horizontal direction from a base member connected to the arm end of a transfer robot (not shown), and has a pair of hook claws 11 extending in a bifurcated shape in a plan view. It is formed of a high-rigidity lightweight material such as a carbon fiber reinforced resin plate.

[0024] In the present embodiment, the suction portions 100 are provided at two locations, a total of four locations, on the tip side and the base end side of each hook claw 11. The specific configuration of each suction portion 100 will be described below.

[0025] As well shown in FIG. 3, for example, a circular recess 12 is formed in the support plate 10. In this recess 12, the lifting body 20 is accommodated while being guided to move up and down with a certain stroke. A ring-shaped guide body 13 is fitted in the recess 12. This guide body 13 has a guide surface 131 in the shape of a cylindrical inner surface, and an inward flange 132 that defines the upper end of the movement stroke of the lifting body 20 adjacent to the upper end of the guide surface 131.

[0026] The lifting body 20 is a circular member in plan view having an outer peripheral thick portion 21 and an inner peripheral thin portion 22. The thick portion 21 has a cylindrical outer surface 211, and an outward flange 212 is formed adjacent to the lower end of the cylindrical outer surface 211. The outer diameter of the cylindrical outer surface 212 substantially coincides with the inner diameter of the inward flange 132 of the guide body 13 described above, and the outer diameter of the outward flange 212 substantially coincides with the inner diameter of the guide surface 131 of the guide body 13 described above. Thereby, the lifting body 20 is guided by the guide body 13 and can move up and down, and the upper end of the lifting stroke is defined by the outward flange 212 of the lifting body 20 abutting against the lower surface of the inward flange 132 of the guide body 13.

[0027] In the present embodiment, the lifting body 20 is constantly biased upward by an elastic body 30. Specifically, in the thick portion 21 of the lifting body 20, downward cylindrical recesses 213 are provided at three positions spaced 120° apart in the circumferential direction, and engaging recesses 121 are provided at positions in the recess 12 of the support plate 10 facing the respective cylindrical recesses 213. A compression coil spring as the elastic body 30 is interposed between the support plate 10 and the lifting body 20 by engaging its upper end with the cylindrical recess 213 of the lifting body 20 and its lower end with the engaging recess 121.

[0028] A suction hole 221 penetrating in the vertical thickness direction is provided at the center position of the lifting body 20. The suction hole 221 is configured to be able to apply a negative pressure regardless of the position of the lifting body 20 in its lifting stroke, as will be described below. That is, a first pressure port 122 is provided at the center of the bottom of the recess 12 of the support plate 10, and a bellows member as a first cylindrical member 41 that can expand and contract in the vertical direction is provided such that its upper end surrounds the suction hole 221 and is connected to the lower surface of the lifting body 20, and its lower end surrounds the first pressure port 122 and is connected to the recess 12 of the support plate 10. The material of the first cylindrical member 41 (bellows member) is suitably made of rubber, but is not limited thereto.

[0029] On one hand, a configuration is provided for lowering the lifting body 20 against the elastic force of the elastic body 30 described above by the action of negative pressure. Specifically, a second pressure port 123 is provided at the bottom of the concave portion 23 of the support plate 10, and a bellows member as a second cylindrical member 42 that can expand and contract in the vertical direction is provided such that its upper end is connected to the lower surface of the lifting body 20 and its lower end is connected to the concave portion 12 of the support plate 10 surrounding the second pressure port 42. As the material of the first cylindrical member 42 (bellows member), it is appropriate that it is made of rubber, but it is not limited to this. In the present embodiment, the configuration including the second pressure port 123 and the second cylindrical member 42 is provided at three locations spaced 120° circumferentially around the center of the lifting body 20.

[0030] The first pressure port 122 is communicated with a negative pressure source 610 such as a vacuum pump via a first negative pressure path 51 having a first on-off valve 511 in the middle, and the second pressure port 123 is communicated with a negative pressure source 620 such as a vacuum pump via a second negative pressure path 52 having a second on-off valve 522 in the middle. In the present embodiment, the first negative pressure path 51 is formed by forming a concave groove 14 on the lower surface of the support plate 10 in the region of the support plate 10 and closing the lower opening of the concave groove 14 with a thin plate 15. Similarly, the second negative pressure path 52 is also formed by forming a concave groove 14 on the lower surface of the support plate 10 and closing the lower opening of the concave groove 14 with a common thin plate 15.

[0031] In addition, in the present embodiment, an adsorbent 23 made of rubber or the like that expands upward in a trumpet shape surrounding the suction hole 221 is provided on the upper surface of the lifting body 20, but whether to provide such an adsorbent 23 is an optional matter.

[0032] Next, the operation of the work transfer hand A1 having the above configuration will be described.

[0033] As shown in FIG. 3, when the negative pressure to the second pressure port 123 is blocked by the operation of the second on-off valve 522, the lifting body 20 is positioned at the upper end of the lifting stroke by the upward biasing force of the elastic body 30 (compression coil spring 31), and the amount of protrusion with respect to the support plate 10 increases. On the other hand, as shown in FIG. 5, when negative pressure is applied to the second pressure port 123, the bellows member as the second cylindrical member 42 is contracted, and the amount of protrusion of the lifting body 20 with respect to the support plate 10 decreases. In the present embodiment, the elastic bodies 30 are arranged at three locations at equal intervals around the center of the lifting body 20, and the elements for lowering the lifting body 20 including the second pressure port 123 and the second cylindrical member 42 (bellows member) are also arranged at three locations at equal intervals around the center of the lifting body 20. Therefore, a situation where the lifting body 20 is inclined during the lifting and lowering process and gets jammed and locked with the guide body 13 is avoided, and the lifting body 20 can be smoothly lifted and lowered.

[0034] Then, as shown in FIGS. 4 and 6, when the lifting body 20 is positioned at the upper end of the lifting stroke or at the lower end of the lifting stroke, when negative pressure is applied to the first pressure port 122 by the operation of the first on-off valve 511, negative pressure acts on the suction holes 221 or the adsorbing body 23 of the lifting body 20 through the first cylindrical member 41 (bellows member), and the plate-shaped workpiece W placed on the workpiece transfer hand A1 can be adsorbed and held from its lower surface.

[0035] Thus, the workpiece transfer hand A1 having the above configuration can appropriately change the amount of protrusion of the lifting body 20 with respect to the support plate 10, and can adsorb and hold the plate-shaped workpiece W regardless of the amount of protrusion of the lifting body 20.

[0036] Therefore, even when the vertical interval of the plate-shaped workpieces W stored in or to be stored in the cassette becomes small due to the deflection of the plate-shaped workpieces W or the difference in the amount of deflection of the plate-shaped workpieces W adjacent above and below, by performing an operation such as reducing the amount of protrusion of the lifting body 20 when the workpiece transfer hand A1 is inserted into or pulled out from the cassette, the plate-shaped workpieces W can be properly transferred to and from the cassette.

[0037] In addition, in the workpiece transfer hand A1, a configuration (elastic body 30) for constantly biasing the lifting body 20 in the vertical direction is provided separately from the configuration (first cylindrical member 41) for applying negative pressure to the suction holes 221 regardless of the vertical position of the lifting body 20. Therefore, when negative pressure is applied to the suction holes 221 to adsorb and hold the plate-shaped workpiece W, the vertical position of the lifting body 20 can be stabilized.

[0038] Of course, the present invention is not limited to the above-described embodiments, and the above embodiments can be modified as follows.

[0039] That is, as the elastic body 30, for example, a tension coil spring that constantly biases the lifting body 20 downward is changed, and as a pressure source for the pressure to be applied to the second pressure port 123, for example, a compressor that generates positive pressure is changed.

[0040] In this case, when the positive pressure to the second pressure port 123 is blocked by the operation of the second on-off valve, the lifting body 20 is positioned at the lower end of the lifting stroke by the downward biasing force of the elastic body 30 (tension coil spring), and the protrusion amount with respect to the support plate 10 becomes small. On the other hand, when positive pressure is applied to the second pressure port 123, the second cylindrical member 42 (bellows member) is extended, and the lifting body 20 is positioned at the upper end of the lifting stroke, and the protrusion amount with respect to the support plate 10 becomes large.

[0041] And when the lifting body 20 is positioned at the upper end of the lifting stroke or at the lower end of the lifting stroke, when negative pressure is applied to the first pressure port 122 by the operation of the first on-off valve 511, negative pressure acts on the suction holes 221 or the adsorbing body 23 of the lifting body 20 through the first cylindrical member 41 (bellows member), and the plate-shaped workpiece W placed on the workpiece transfer hand A1 can be adsorbed and held from its lower surface.

[0042] All changes within the scope of the matters described in each claim are included in the present invention.

Explanation of Reference Numerals

[0043] A1: Hand for workpiece transfer, W: Plate-shaped workpiece, 10: Support plate, 12: Recess, 122: First pressure port, 123: Second pressure port, 20: Lifting body, 221: Suction hole, 30: Elastic body, 41: First cylindrical member, 42: Second cylindrical member, 51: First negative pressure path, 52: Second negative pressure path, 100: Adsorption part, 610, 620: Negative pressure source

Claims

1. A work transfer hand comprising a support plate and a plurality of suction portions provided so as to face the upper surface of the support plate, wherein the support plate has a recess recessed from its upper surface, and a first pressure port and a second pressure port are provided at the bottom of the recess, and the suction portion includes in the recess, a lifting body that is guided to be liftable with a predetermined stroke distance and has a suction hole penetrating in the vertical thickness direction at the center, an elastic body interposed between the lifting body and the support plate to constantly bias the lifting body upward or downward, between the lifting body and the bottom of the recess, a bellows-like first cylindrical member having an upper end connected to the lower surface of the lifting body so as to surround the suction hole and a lower end connected to the bottom so as to surround the first pressure port, and being stretchable in the vertical direction, between the lifting body and the bottom of the recess, a bellows-like second cylindrical member having an upper end connected to the lower surface of the lifting body and a lower end connected to the bottom so as to surround the second pressure port, and being elastically stretchable in the vertical direction, and includes a plurality of sets of the second pressure port and the second cylindrical member are provided outside the first cylindrical member in the radial direction, and a plurality of the elastic bodies are provided outside the second cylindrical member in the radial direction separately from the first cylindrical member and the second cylindrical member. A work transfer hand characterized by the above.

2. The elastic body constantly biases the lifting body upward, the first pressure port communicates with a negative pressure source via a first on-off valve, and the second pressure port communicates with an additional negative pressure source via a second on-off valve. The work transfer hand according to Claim 1.

3. The elastic body constantly biases the lifting body downward, the first pressure port communicates with a negative pressure source via a first on-off valve, and the second pressure port communicates with a positive pressure source via a second on-off valve. The work transfer hand according to Claim 1.

4. On the upper surface of the lifting body, there is provided a suction body that expands upward in a trumpet shape and is elastically deformable. The work transfer hand according to any one of Claims 1 to 3.

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