JP2008023669A - Transfer system and transfer method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a transfer system and a transfer method, capable of surely transferring an object to be transferred while grasping a retaining force of a suction gripper. <P>SOLUTION: In transferring the object 11 to be transferred with the suction gripper 14, even if a part of the object 11 to be transferred has a permeable portion, a generated retaining force of the suction gripper 14 is grasped before the permeable portion is retained and transferred with the suction gripper 14, that is, before the object 11 to be transferred is lifted up with a delivery station 12A. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a transfer system and a transfer method, and more particularly to a technique that can reliably transfer a transfer object such as a television receiver.

  The assembly of a thin television receiver such as a liquid crystal is performed through various processes, but the lines need to be separated due to the nature of each process. For this reason, it is often necessary to transfer a television receiver that is being assembled between two lines. If the television receiver has a handle, the gripping is easy and causes no problem, but if the handle is not attached, a gripping method for transferring the television receiver is difficult.

  There is a method of gripping the top, bottom, or side of the television receiver. However, if the television receiver becomes large and the weight of the model to be produced is near 500N, the gripped part of the television receiver will be damaged. Or the gripping part may wear out quickly. When the speaker is attached to the lower surface of the television receiver, the speaker may be damaged when the television receiver is gripped.

  FIG. 12 is a diagram illustrating the suction pad unit 1 including a common vacuum path according to the related art. In order to solve the above-described problem, a technique for transferring the object to be transferred by vacuum suction has been considered (for example, see Patent Document 1). This is a technique for holding a transfer object having a small hole by vacuum suction using an adsorption gripper in which each of a large number of suction ports formed in the suction plate is connected to a common chamber by piping. A plurality of types of adsorption grippers according to the prior art have been proposed.

  One adsorption gripper reduces the influence of reducing the ultimate vacuum by reducing the hole leading to the common chamber even if a part of the many adsorption ports adsorbs a portion having air permeability. When another part of the adsorption gripper adsorbs a breathable part, the adsorption port of that part is closed by a check valve.

JP 2005-195257 A

  There are various types of television receivers, and it is desirable to produce an adsorption gripper that can be applied to as many models as possible. However, the back of the television receiver has air-permeable parts such as heat-dissipating slits, and even if the back of the television receiver is adsorbed by the adsorption gripper, a part of the adsorption part of the adsorption gripper is air-permeable. I have to touch a certain part.

  When using the conventional adsorption gripper, it is impossible to determine whether the reduction in the ultimate vacuum is due to adsorption of a part with high air permeability or due to poor adsorption, and the holding force of the adsorption gripper cannot be grasped. I have to use it.

  When the other conventional suction grippers are used, the ultimate vacuum does not decrease, but when there are few effective suction ports, the number of suction ports, that is, the suction area cannot be grasped, and the necessary and sufficient suction force (holding force) ) Will not be obtained.

  The objective of this invention is providing the transfer system and transfer method which can transfer a transfer target object reliably, grasping | ascertaining the holding force of an adsorption | suction gripper.

The present invention incorporates a check valve and an adsorption gripper for adsorbing a transfer object;
Means for depressurizing the inside of the adsorption gripper;
Means for detecting and controlling the degree of vacuum inside the adsorption gripper;
A station for transporting the transfer object, the station including weight detection means for detecting the weight of the transfer object,
Means for calculating a holding force of the transfer object by the suction gripper based on the weight detected by the weight detection means;
Means for determining the degree of vacuum inside the suction gripper necessary for transferring the transfer object from the holding force calculated by the means for calculating, and determining whether the transfer object can be transferred And a transfer system characterized by comprising:

The present invention also includes an adsorption gripper that incorporates a check valve and adsorbs a transfer object, a means for depressurizing the inside of the adsorption gripper, a means for detecting and controlling the degree of vacuum inside the adsorption gripper, and a transfer A station that transports an object, including a weight detection unit that detects the weight of the transfer object, and holding the transfer object by the suction gripper based on the weight detected by the weight detection unit A method of transferring a transfer object by a transfer system comprising means for calculating force,
The degree of vacuum inside the suction gripper is controlled so that a holding force by the suction gripper equal to or less than the weight of the transfer object is generated while the suction gripper is in contact with the transfer object. And a process of
After the step, by calculating the actual holding force of the adsorption gripper at the degree of vacuum by the means for detecting by the weight detection means a value obtained by reducing the weight of the transfer object;
After the step, the degree of vacuum inside the suction gripper is increased, and after the suction gripper generates a holding force exceeding the holding force necessary for transferring the transfer object, a transfer operation is performed. It is the transfer method characterized by this.

  According to the present invention, the weight of the transfer object is detected by the weight detection means. Based on the detected weight, the holding force of the transfer object is calculated. From this calculated holding force, the degree of vacuum inside the suction gripper necessary for transferring the transfer object is determined, and whether or not the transfer object can be transferred is determined.

  Therefore, it is possible to grasp the necessary and sufficient holding force for holding the transfer object without being affected by the presence or absence of air permeability of the transfer object. Therefore, it is possible to reliably transfer the transfer object.

  In addition, according to the present invention, the degree of vacuum inside the suction gripper is controlled so that a holding force equal to or less than or equal to the weight of the transfer object is generated with the suction gripper in contact with the transfer object. To do. Thereafter, a value obtained by reducing the weight of the transfer object is detected by a weight detection means. Thus, the actual holding force of the suction gripper at the vacuum degree is calculated. Thereafter, the degree of vacuum inside the suction gripper is increased, a holding force exceeding the holding force necessary for transferring the transfer object is generated, and then the transfer operation is executed.

  In this way, once the balance with the weight of the transfer object is balanced, the degree of vacuum inside the adsorption gripper is controlled, and then the degree of vacuum inside the adsorption gripper is increased stepwise based on the actual holding force of the adsorption gripper. Therefore, the transfer object can be transferred without undesirably dropping. In other words, the transfer object can be reliably transferred while grasping the holding force of the suction gripper.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. The transfer system according to the present embodiment is applied to a system for transferring a television receiver. However, the transfer object is not necessarily limited to the television receiver, and may be an electronic device other than the television receiver, various parts, or the like. The following description also includes a description of a method for transferring the transfer object.

  FIG. 1 is a diagram showing the overall configuration of a transfer system 10 according to an embodiment of the present invention. The transfer system 10 according to the present embodiment is a system for transferring a television receiver 11 as a transfer object from a payout station 12A to a receiving station 12B (see FIG. 3). These payout side and receiving side stations 12A and 12B may be simply referred to as “stations”. The transfer system 10 includes a transfer device and a payout side station 12 </ b> A including a load cell 13. The transfer apparatus includes an adsorption gripper 14, a compressed air supply source (not shown), a regulator 15 which is a vacuum degree adjusting machine, an ejector 16, calculation and determination means 17 and 18, and a vacuum switch 19.

  The suction gripper 14 is a suction unit that sucks the television receiver 11, and is configured so as to be in contact with and separated from the television receiver 11. An adsorption gripper 14 to be described later is connected to an ejector 16 by piping so that the inside thereof becomes a vacuum. The ejector 16 is connected by piping to a compressed air supply source via a regulator 15.

  The compressed air from the compressed air supply source is reduced to an arbitrary pressure by adjusting the regulator 15 and sent to the ejector 16. As a result, air in the space inside the suction gripper 14 connected to the ejector 16 by piping and air entering the inside of the suction gripper from outside the suction gripper are sucked into the ejector 16. Therefore, if the suction port of the suction gripper 14 is blocked, the ultimate vacuum in the chamber of the suction gripper 14 increases.

  A vacuum switch 19 is electrically connected to the suction gripper 14. The ultimate vacuum of the suction gripper 14 is measured by the vacuum switch 19, the regulator 15 is operated according to the excess or shortage of the ultimate vacuum, and the supply pressure (and hence the supply flow rate) of the compressed air is adjusted to reach the required reach. A degree of vacuum is obtained. The vacuum switch 19 is also connected to the calculation and determination means 17 and 18 in data communication.

Therefore, the value of the ultimate vacuum is transmitted to the calculation and determination means 17 and 18. In the calculation and determination means 17 and 18, the holding force of the suction gripper 14 is calculated by a pre-calculated formula, and it is determined whether or not the television receiver 11 as the transfer object can be transferred. . The calculation and judgment means 17 and 18 are, for example, a central processing unit (Central
This is realized by a processing unit (abbreviated CPU). As a result, if it is determined that transfer is possible, the transfer apparatus proceeds to the next operation. An alarm is output when it is determined that transfer is impossible. The vacuum switch 19 and the CPU correspond to means for detecting and controlling the degree of vacuum inside the suction gripper.

  FIG. 2 is a plan view of the pallet 20 showing the arrangement of the load cells 13 in the transfer system 10. FIG. 3 is a diagram illustrating an example of a production line that is transferred by the transfer system 10. This will be described with reference to FIG. The payout-side station 12A has a function of transporting the transfer object, and includes a station main body 21, a transport roller 22, a side regulating roller 23, a measurement lifter 24, a load cell 13, and a pallet 20. Including. The station main body 21 is installed along the longitudinal direction of the line, and the length in the width direction is defined according to the size of the transfer object. The length of the station body 21 in the width direction is defined as the x direction, and the height direction of the station body 21 is defined as the z direction. The direction orthogonal to the x and z directions is defined as the y direction. 1 and 2, the x, y, and z directions are represented by arrows x, y, and z, respectively. A virtual plane including the x and y directions is referred to as an xy plane.

  The station body 21 is a frame body that opens in one direction in the z direction. Among the inner walls, at one end in the z direction, a plurality of transfer rollers 22 for transferring the transfer object in one direction or the other in the y direction, that is, transferring the pallet 20 for placing and supporting the transfer object from the previous process, They are arranged at appropriate intervals along the y direction. Each conveyance roller 22 is configured to be rotatable about an x-direction axis. A plurality of side surface regulating rollers 23 that regulate one side surface portion and the other side surface portion of the pallet 20 in the opening edge portion of the station main body 21 are arranged at appropriate intervals along the y direction. Each side regulating roller 23 is configured to be rotatable about the z-direction axis.

  The pallet 20, the measurement lifter 24, and the load cell 13 are provided in the station main body 21 of the payout side station 12 </ b> A. The pallet 20 is formed in a rectangular shape in plan view, and the front part 11a of the television receiver 11 as a transfer object is placed on one surface part 20a (that is, the upper part) in the z direction. Four load cells 13 are disposed on the other surface portion (that is, the lower portion) in the z direction of the pallet 20. These load cells 13 are arranged at positions inside a predetermined small distance from the four corners of the pallet 20, and are configured such that the weight of the television receiver 11 can be measured by the payout side station 12A. “Plan view” is synonymous with viewing in one of the z directions.

  The measurement lifter 24 can measure the weight of at least one of the pallet 20 and the transfer object, and is configured to be movable up and down in one and the other in the z direction. The measurement lifter 24 includes a lifter body and a drive mechanism (not shown) that drives the lifter body up and down. The lifter body is formed in a rectangular shape in plan view, and four load cells 13 are provided along the four corners of the one surface portion 24a. These load cells 13 are set to zero in a state where only the pallet 20 is placed in order to measure the weight of the television receiver 11 itself.

The adsorption gripper 14 will be described.
FIG. 4 is a cross-sectional view showing a part of the adsorption gripper 14 by breaking it. FIG. 5 is a plan view of the suction gripper 14 showing the arrangement of the plurality of suction ports 27a. The adsorption gripper 14 includes an adsorption gripper main body 25, a plurality of chuck valves 26 that are check valves, and a sponge portion 27. A plurality of chuck valves 26 are provided at the tip of the suction gripper body 25 in the z direction. The chuck valves 26 are arranged along the xy plane, and are arranged at regular intervals in the x direction and at regular intervals in the y direction.

  A sponge portion 27 having a certain thickness is fixed to the tip portion of the suction gripper 14 in the z direction via the plurality of chuck valves 26. The sponge part 27 is an elastic body made of a sponge and is elastically deformable. In the sponge part 27, a plurality of suction ports 27a respectively connected to the ports of the chuck valves 26 are formed. The plurality of suction ports 27a are connected to a common chamber 28 through corresponding chuck valves 26, respectively. The plurality of suction ports 27a are arranged along the xy plane, and are arranged at regular intervals in the x direction and at regular intervals in the y direction.

  In the suction gripper 14 according to the present embodiment, even if a part of the suction port 27a is in a vented state among the plurality of suction ports 27a sucked by the transfer object, the suction port 27a of that portion is formed by the check valve 26. Block it. Therefore, regardless of whether or not all the suction ports 27a are blocked, the ultimate vacuum reaches a predetermined vacuum (for example, about −80 kPa).

  6 shows an example of the structure of the check valve 26 of the adsorption gripper 14, and FIG. 6A is a cross-sectional view showing a state in which a valve passage through which a fluid can flow from one side to the other is opened, FIG. These are sectional views showing the state where the valve passage was obstructed. The check valve 26 includes a valve body 29, a sphere 30, a compression coil spring 31 and a spring stopper piece 32. In the vicinity of the inlet port of the valve main body 29, a flange 29a having a diameter reduced radially inward from the inner peripheral portion of the valve main body 29 is formed. A spring stopper piece 32 is provided near the middle of the valve body 29 in the axial direction. In the valve main body 29, the spherical body 30 is provided between the spring stopper piece 32 and the flange portion 29a so as to be movable in the axial direction. A compression coil spring 31 is provided between the bottom of the sphere 30 and the spring stopper piece 32.

  Due to the spring force of the compression coil spring 31, the spherical body 30 presses the seat portion attached to the flange 29a. As shown in FIG. 6 (a), air flows from the inlet port to the outlet port against the spring force, but when air tries to flow from the outlet port to the inlet port, it is shown in FIG. 6 (b). As such, the flow path is closed. Therefore, even if the portion of the adsorption gripper 14 that is in contact with the breathable portion on the lower side is exhausted from the other side (that is, the upper side) as shown in FIG. 6B, the check valve 26 works and the adsorption port. 27a is closed.

  FIG. 7 is a diagram illustrating the relationship between the rear surface 11b of the television receiver 11 as an example of the transfer object and the arrangement position of the suction gripper 14 in which the plurality of suction ports 27a are formed. FIG. 8 is a diagram illustrating the relationship between the rear surface 11b of the television receiver 11 as another example of the transfer object and the arrangement position of the suction gripper 14 in which the plurality of suction ports 27a are formed. 7 and 8 show a state where the suction port 27a of the suction gripper 14 is in contact with the back surface 11b of the television receiver 11. FIG. On the rear surface of the television receiver 11, hatched slits, blisters, etc. are formed, and their positions and sizes vary depending on the type of the television receiver 11. 7 and 8, the portion where the suction port 27a overlaps the hatched portion HT is in a vented state.

  In the case of the television receiver 11, in order to hang the television receiver 11 on a wall or the like, the vicinity of the center of the back surface 11b of the television receiver 11 has a relatively non-breathable portion. Therefore, the suction gripper 14 to be used is calculated and manufactured so that the suction port 27a in contact with this portion common to many models generates a necessary holding amount. Even in this case, depending on the type of the television receiver 11, the positional relationship between the rear surface 11b of the television receiver 11 and the suction port 27a of the suction gripper 14 is taken into consideration, and the number of suction ports 27a in contact with the non-breathable portion is the largest. Needless to say, the suction gripper 14 is moved in the xy direction and brought into contact with such a position.

  FIG. 9 is a diagram illustrating the relationship between the compressed air supply pressure, the compressed air consumption, and the ultimate vacuum level of the vacuum generator used for the adsorption gripper 14. When a vacuum is generated using the ejector 16, the ultimate vacuum increases as the supply pressure of the compressed air increases, and as the flow rate of the compressed air increases.

  FIG. 10 is a diagram illustrating the relationship between the ultimate vacuum of the suction gripper 14 and the holding force of the suction pad. The solid line in the figure shows the relationship between the ultimate vacuum and the holding force by the ratio {(effective number of suction ports) / (number of all suction ports)} obtained by dividing the number of effective suction ports by the total number of suction ports. is there. For example, it is necessary to transfer the television receiver 11 with the suction gripper 14 in a state along the xy plane (that is, in a horizontal state) on the condition that the weight of the television receiver 11 to be transferred is 500 N. The holding force of the suction gripper 14 must be 1000 N or more. This portion is indicated by hatching in FIG.

Next, the transfer operation in the transfer system 10 configured as described above will be described.
FIG. 11 is a flowchart showing stepwise the transfer method according to the embodiment of the present invention. The control subject of this process is the CPU. The transfer method according to the present embodiment generates a holding force by the suction gripper 14 equal to or less than or equal to the weight of the transfer object in a state where the suction gripper 14 is in contact with the transfer object. A process of controlling the degree of vacuum inside the adsorption gripper (step a1), and after the process, a value obtained by reducing the weight of the object to be transferred is detected using the load cell 13, thereby adsorbing at the degree of vacuum. The step of calculating the actual holding force of the gripper 14 by the CPU (step a2), and after the step, the degree of vacuum inside the suction gripper is increased, and the suction gripper 14 exceeds the holding force necessary for transferring the transfer object. A step (step a3) of executing a transfer operation after generating the holding force.

  Specifically, as shown in FIGS. 1 and 3, when the television receiver 11 placed on the pallet 20 sent from the previous process reaches the dispensing station 12A, the pallet 20 is moved to the station main body 21. Stop with a stopper, etc., not shown. In this state, the measurement lifter 24 operates. Four load cells 13 provided in the measurement lifter 24 come into contact with the pallet 20, the four load cells 13 measure the weights of the television receiver 11 and the pallet 20, and the added value is calculated. However, in this case, if the load cell 13 is reset in a state where only the pallet 20 is placed in advance on the four load cells 13, the measured value (A1 + A2 + B1 + B2) of the load cell 13 is a value only of the weight of the television receiver 11, For example, 500 N is shown.

Next, the suction gripper 14 of the transfer machine is pressed against the back surface 11 b of the television receiver 11. In this state, when the regulator 15 is adjusted and the ejector 16 is operated so that the ultimate vacuum of the suction gripper 14 is set to -16 kPa, the television receiver 11 cannot be lifted. The total value is displayed in small numbers. Accordingly, the holding force H of the suction gripper 14 at this time is a value obtained by subtracting the total value of the four load cells 13 from the weight of the television receiver 11. In other words, it is expressed as follows.
Holding power H = (Weight of television receiver) − (Total value of four load cells)

  This value is calculated by calculation means realized by the CPU. Here, if all of the suction ports 27a of the suction gripper 14 are working effectively, the holding force of the suction gripper 14 is 400 N from FIG. However, as shown in FIGS. 7 and 8, the rear surface of the television receiver 11 has a structure in which a part of the suction port 27a of the suction gripper 14 adsorbs a breathable part. Therefore, the suction port 27a at that portion is closed by the check valve 26 and does not contribute to the holding force. That part becomes an invalid suction port. Therefore, if the holding force H is calculated to be 300 N when the suction gripper 14 sucks the back surface 11b of the television receiver 11, it can be seen from FIG. 10 that the number of effective suction ports of the suction gripper 14 is 80% of the total. Show.

  When using the suction gripper 14 along the xy plane (in a horizontal state) to transfer the transfer object, the holding force of the suction gripper 14 is required to be at least twice the weight of the transfer object as a guide. ing. Therefore, in order to securely hold and transfer the 500 N television receiver 11, it is necessary to generate a holding force of 1000 N or more obtained by multiplying the 500 N by “2” in the suction gripper 14. The region is indicated by hatching in FIG. Therefore, when the number of effective suction ports is 80%, it is possible to generate a holding force necessary for holding and transferring the transfer object by increasing the ultimate vacuum to −51 kPa or more.

  After the ultimate vacuum is measured by the vacuum switch 19 and it is confirmed that the value has reached −51 kPa or more, the transfer operation of the television receiver 11 to be transferred and transferred to a moving mechanism (not shown) is performed. . The aforementioned calculation and determination means 17 and 18 perform these calculations and determinations. Here, when the ultimate vacuum of the suction gripper 14 is set to -16 kPa at the dispensing station 12A, the ultimate vacuum of the suction gripper 14 is set to -80 kPa when the holding force is calculated as 150 N and the effective suction port is calculated as 40%. Will not exceed 1000N.

  Therefore, in this case, the determination unit 18 determines that transfer is not possible (that is, NO), and outputs an alarm, for example. When the alarm is output, the cause is checked manually, the cause is removed, and then the origin is returned. In the present embodiment, a television receiver is taken as an example of the transfer object, but it is sufficient if the suction gripping surface has a certain level of plane and a part having air permeability. There is no limitation on the object.

  According to the transfer system 10 and the transfer method described above, when a transfer object such as the television receiver 11 is transferred by the suction gripper 14, a part of the transfer object has a breathable part. Even if it is, it produces the following effects. By grasping the generated holding force of the suction gripper 14 before holding and transferring the breathable portion by the suction gripper 14, that is, before lifting the transfer target object at the dispensing station 12A, the transfer target object is It can be transferred reliably. If it is determined that the transfer object cannot be transferred, an alarm is output so that the transfer operation is not performed.

1 is a diagram illustrating an overall configuration of a transfer system 10 according to an embodiment of the present invention. 4 is a plan view of a pallet 20 showing the arrangement of load cells 13 in the transfer system 10. FIG. It is a figure showing an example of the production line transferred by this transfer system. It is sectional drawing which fractures | ruptures and represents some adsorption | suction grippers. It is a top view of adsorption gripper 14 showing arrangement of a plurality of adsorption openings 27a. 6A shows an example of the structure of the check valve 26 of the adsorption gripper 14, FIG. 6A is a cross-sectional view showing a state in which a valve passage through which fluid can flow from one side to the other is opened, and FIG. 6B shows a valve passage. It is sectional drawing showing the state by which was closed. It is a figure showing the relationship between the back surface 11b of the television receiver 11 of an example of a transfer target object, and the arrangement position of the adsorption | suction gripper 14 in which the several adsorption opening 27a is formed. It is a figure showing the relationship between the back surface 11b of the television receiver 11 of another example of a transfer target object, and the arrangement position of the adsorption | suction gripper 14 in which the several adsorption opening 27a is formed. It is a figure showing the relationship between the compressed air supply pressure of the vacuum generator used for the adsorption | suction gripper 14, compressed air consumption, and ultimate vacuum. It is a figure showing the relationship between the ultimate vacuum degree of the adsorption | suction gripper 14, and the retention strength of an adsorption pad. It is a flowchart showing the transfer method concerning the embodiment of the present invention in steps. It is a figure showing the suction pad part 1 etc. provided with the common vacuum path | route which concerns on a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Transfer system 12A Dispensing station 13 Load cell 14 Adsorption gripper 15 Regulator 16 Ejector 17 Calculation means 18 Judgment means 26 Check valve

Claims (2)

A suction gripper with a built-in check valve to suck the transfer object;
Means for depressurizing the inside of the adsorption gripper;
Means for detecting and controlling the degree of vacuum inside the adsorption gripper;
A station for transporting the transfer object, the station including weight detection means for detecting the weight of the transfer object,
Means for calculating a holding force of the transfer object by the suction gripper based on the weight detected by the weight detection means;
Means for determining the degree of vacuum inside the suction gripper necessary for transferring the transfer object from the holding force calculated by the means for calculating, and determining whether the transfer object can be transferred The transfer system characterized by having. An adsorption gripper that incorporates a check valve and adsorbs the transfer object, a means for depressurizing the inside of the adsorption gripper, a means for detecting and controlling the degree of vacuum inside the adsorption gripper, and a transfer object A station including a weight detection means for detecting the weight of the transfer object, and a means for calculating a holding force of the transfer object by the suction gripper based on the weight detected by the weight detection means A method of transferring a transfer object by a transfer system comprising:
The degree of vacuum inside the suction gripper is controlled so that a holding force by the suction gripper equal to or less than the weight of the transfer object is generated while the suction gripper is in contact with the transfer object. And a process of
After the step, by calculating the actual holding force of the adsorption gripper at the degree of vacuum by the means for detecting by the weight detection means a value obtained by reducing the weight of the transfer object;
After the step, the degree of vacuum inside the suction gripper is increased, and after the suction gripper generates a holding force exceeding the holding force necessary for transferring the transfer object, a transfer operation is performed. A transfer method characterized by that.

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