Workpiece transfer device and suction pad inspection method

Abstract

The objective is to provide a workpiece transfer device and a suction pad inspection method that can detect defects in the suction pad in advance and prevent a decrease in productivity and equipment downtime. [Solution] In a workpiece transfer device that uses a suction pad in contact with a workpiece and sucks air through a nozzle connected to the suction pad to lift the workpiece that has been sucked onto the suction pad and transfer it to a predetermined location, the suction pad 23 is in contact with a dummy part that mimics a workpiece and air is sucked through the nozzle, and an attempt is made to lift the dummy part in that state (ST3~ST5), and the flow rate of the air flowing through the nozzle is measured in that state (ST6). Then, based on the measured air flow rate, it is determined whether or not the suction pad is sucking onto the dummy workpiece (ST7, ST8, ST13), and based on the result of that determination, the quality of the suction pad is determined (ST12, ST14).

Description

Technical Field

[0001] The present disclosure relates to a work transfer device that adsorbs a work by an adsorption pad and transfers it to a predetermined location, and a method for inspecting the adsorption pad in the work transfer device.

Background Art

[0002] Conventionally, as a work transfer device that adsorbs a work by an adsorption pad and transfers it to a predetermined location, for example, air is sucked through a nozzle connected to the adsorption pad while the adsorption pad is in contact with the work, and thereby the work adsorbed on the adsorption pad is lifted and mounted on a substrate. A component mounting device is known (for example, Patent Document 1 below). In such a work transfer device, since the work can be strongly held by the vacuum adsorption force through the adsorption pad, the work can be reliably picked up even when transferring a heavy work.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, suction pads can deteriorate over time, resulting in "sagging" or "cracking." When a suction pad becomes defective due to "sagging" or "cracking," air leaks occur between the suction pad and the workpiece. This prevents the suction pad from generating enough negative pressure to hold the workpiece, making it impossible to lift (pick up) the workpiece. Furthermore, the acceleration load caused by the movement of the suction pad can cause the workpiece to fall, potentially damaging the workpiece or units within the production equipment. Such incidents can have a significant impact on the continuation of production. Therefore, defective suction pads need to be replaced with replacement (new) suction pads. However, operators usually only notice that a suction pad is defective when it actually fails to hold a workpiece during the production process. Consequently, replacing a suction pad requires temporarily stopping the equipment, which can reduce the productivity of the equipment.

[0005] Therefore, the present disclosure aims to provide a workpiece transfer device and a suction pad inspection method that can detect defects in the suction pad in advance and prevent a decrease in productivity and equipment shutdown. [Means for solving the problem]

[0006] The workpiece transfer device of the present disclosure is a workpiece transfer device comprising a head unit that sucks air through a nozzle connected to a suction pad while the suction pad is in contact with a workpiece, thereby lifting the workpiece that has been sucked onto the suction pad and transferring it to a predetermined location, the head unit comprising: a dummy workpiece that mimics the workpiece; a lifting trial means that sucks air through the nozzle while the suction pad is in contact with the dummy workpiece and attempts to lift the dummy workpiece in that state; a flow meter side unit that measures the flow rate of air flowing through the nozzle while the lifting of the dummy workpiece is being attempted; a determination unit that determines whether or not the suction pad is sucking onto the dummy workpiece based on the flow rate of air measured by the flow meter side unit; and a determination unit that determines the quality of the suction pad based on the determination result by the determination unit.

[0007] The suction pad inspection method of the present disclosure is a suction pad inspection method in a workpiece transfer device equipped with a head unit that sucks air through a nozzle connected to the suction pad while the suction pad is in contact with a workpiece, thereby lifting the workpiece that has been sucked up by the suction pad and transferring it to a predetermined location, comprising: a lifting trial step in which the suction pad is in contact with a dummy workpiece that mimics the workpiece, air is sucked up through the nozzle, and an attempt is made to lift up the dummy workpiece in that state; a flow rate measurement step in which the flow rate of air flowing through the nozzle is measured while the attempt is being made to lift up the dummy workpiece; a determination step in which it is determined whether or not the suction pad is sucking up the dummy workpiece based on the flow rate of air measured in the flow rate measurement step; and a determination step in which the quality of the suction pad is determined based on the determination result in the determination step. [Effects of the Invention]

[0008] According to this disclosure, it is possible to detect defects in the suction pads in advance and prevent a decrease in productivity and equipment downtime. [Brief explanation of the drawing]

[0009] [Figure 1] This is a simplified diagram of the main components of a component mounting device in one embodiment of the present disclosure. [Figure 2] (a) and (b) are side views of a lifting shaft and a suction component attached to the lifting shaft, which are part of the head portion of a component mounting device in one embodiment of the present disclosure. [Figure 3] (a) and (b) are side views of a suction component provided in a component mounting device according to one embodiment of the present disclosure. [Figure 4] This is a pneumatic circuit diagram relating to the head portion of a component mounting device in one embodiment of the present disclosure. [Figure 5] This figure shows the combination of operations between a vacuum valve and a blow valve that constitute a valve unit in a component mounting device according to one embodiment of the present disclosure. [Figure 6](a) is a plan view of the shutter of the exchange stand of a component mounting device in one embodiment of the present disclosure in the closed position, and (b) is a plan view of the shutter in the open position. [Figure 7] (a) is a partial cross-sectional side view of a component mounting device in one embodiment of the present disclosure with the shutter of the replacement table in the open position, and (b) is a partial cross-sectional side view of the shutter in the closed position. [Figure 8] This is a block diagram showing the control system of a component mounting device in one embodiment of the present disclosure. [Figure 9] (a), (b), and (c) are side views showing the head portion of a component mounting device in one embodiment of the present disclosure, together with the component, while it is performing a component mounting operation. [Figure 10] (a) and (b) are side views illustrating how a dummy component is attracted to a suction pad when the suction pad of a component mounting device in one embodiment of the present disclosure is functioning well. [Figure 11] (a) and (b) are side views illustrating how a dummy component is not attracted to a component mounting device when the suction pad is defective. [Figure 12] This flowchart shows the procedure for performing a suction pad inspection operation performed by a component mounting device in one embodiment of the present disclosure. [Figure 13] (a), (b), and (c) are side views showing the head portion of a component mounting device in one embodiment of the present disclosure, along with a dummy component, when it is performing a suction pad inspection operation. [Figure 14] (a)(b)(c)(d) are side views showing a component mounting device in one embodiment of the present disclosure replacing a defective suction component with a replacement suction component. [Figure 15] This is a side view showing a modified example of a dummy component that is picked up by a suction pad of a component mounting device in one embodiment of the present disclosure. [Modes for carrying out the invention]

[0010] Hereinafter, embodiments in the present disclosure will be described with reference to the drawings. FIG. 1 shows a component mounting apparatus 10 as a work transfer apparatus in an embodiment of the present disclosure. The component mounting apparatus 10 is an apparatus that performs an operation (component mounting operation) of transferring a component BH, which is a work, to a substrate KB, and includes a substrate positioning unit 11, a component supply unit 12, a head unit 13, a head unit moving mechanism 14, a valve unit 15, a flow sensor 16, a dummy component placement unit 17, and an exchange table 18.

[0011] In FIG. 1, the substrate positioning unit 11 is composed of a pair of conveyors 11a. The pair of conveyors 11a conveys the substrate KB in a direction perpendicular to the plane of FIG. 1 and positions it at a predetermined position. The component supply unit 12 supplies the component BH to be mounted on the substrate KB.

[0012] In FIGS. 1 and 2(a), (b), the head unit 13 includes a lifting shaft 21 that extends downward. An elevating unit 13L is provided inside the head unit 13, and the lifting shaft 21 moves up and down when the elevating unit 13L operates. The head unit moving mechanism 14 is composed of, for example, an XY table, and moves the head unit 13 in the horizontal plane direction.

[0013] In FIGS. 1 and 2(a), (b), a nozzle 22 is attached to the lower end of the lifting shaft 21. A suction pad 23 is attached to the lower end of the nozzle 22.

[0014] In FIGS. 2(a), (b) and FIGS. 3(a), (b), the nozzle 22 includes a base portion 22a having a cylindrical hole 22T that fits externally on the lower end of the lifting shaft 21, a hollow cylindrical main body portion 22b that extends downward from the base portion 22a, and a disk-shaped flange portion 22c that is located between the base portion 22a and the main body portion 22b and extends and spreads in the horizontal plane.

[0015] In FIGS. 2(a), (b) and FIGS. 3(a), (b), the suction pad 23 is made of, for example, a rubber pad and has a downwardly flaring appearance. The suction pad 23 has a press-fitting portion 23a and a skirt portion 23b extending downward from the press-fitting portion 23a in a conical shape. A press-fitting hole 23H is formed in the press-fitting portion 23a so as to extend downward from the upper end portion.

[0016] The main body portion 22b of the nozzle 22 is press-fitted into the press-fitting hole 23H from above, and the lower end surface 23M of the skirt portion 23b has an annular shape that spreads in the horizontal plane. The area (opening area) in the plan view of the annulus is larger than the opening area at the lower end of the main body portion 22b of the nozzle 22.

[0017] In FIGS. 2(a), (b) and FIGS. 3(a), (b), the lower end of the main body portion 22b of the nozzle 22 is located in the internal space of the skirt portion 23b of the suction pad 23 (referred to as the "inner space 23S of the pad"). Therefore, the nozzle internal flow path 22L is in a state of communicating with the inner space 23S of the pad. In the present embodiment, the nozzle 22 and the suction pad 23 are integrally formed, and hereinafter, the component in which the suction pad 23 is attached to the nozzle 22 is referred to as a "suction component 24".

[0018] In FIGS. 2(a), (b), a shaft internal flow path 21L extending in the vertical direction is provided inside the lifting and lowering shaft 21. The shaft internal flow path 21L is connected to an air pipe line 25 that leads to the outside from the side surface of the lifting and lowering shaft 21. A nozzle internal flow path 22L extending in the vertical direction is provided inside the nozzle 22. In a state where the nozzle 22 (that is, the suction component 24) is attached to the lower end of the lifting and lowering shaft 21, the nozzle internal flow path 22L communicates with the shaft internal flow path 21L (see also FIG. 4).

[0019] In Figures 1 and 4, the valve unit 15 is connected to the air pipeline 25, as well as to the negative pressure supply passage NL, which is a supply passage for negative pressure supplied from the negative pressure source NP, and the positive pressure supply passage PL, which is a supply passage for positive pressure supplied from the positive pressure source PP. As shown in Figure 4, the valve unit 15 includes a vacuum valve 15a and a blow valve 15b. The vacuum valve 15a is connected to the air pipeline 25 and the negative pressure supply passage NL, and the blow valve 15b is connected to the positive pressure supply passage PL and the atmospheric pressure release passage AL. The vacuum valve 15a and the blow valve 15b are connected by a connecting pipeline SL.

[0020] In Figures 1 and 4, the flow sensor 16 is interposed in the air pipeline 25. The flow sensor 16 measures the flow rate of air flowing through the nozzle 22 by measuring the flow rate of air passing through the air pipeline 25. In other words, in this embodiment, the flow sensor 16 is a flow meter side that measures the flow rate of air flowing through the nozzle 22.

[0021] In Figure 4, the vacuum valve 15a and the blow valve 15b are each composed of a two-position switchable electromagnetic solenoid valve. When both the vacuum valve 15a and the blow valve 15b are off (the electromagnetic solenoid is not energized), both the vacuum valve 15a and the blow valve 15b are in the normal position (Figure 4). At this time, the negative pressure air supplied from the negative pressure source NP flows into the air line 25 through the vacuum valve 15a, and the positive pressure air supplied from the positive pressure source PP is blocked by the blow valve 15b. As a result, negative pressure air is supplied to the pad space 23S via the nozzle internal flow path 22L, and suction pressure is generated on the suction pad 23 via the nozzle 22 (see the "Suction" section in Figure 5).

[0022] On the other hand, when both the vacuum valve 15a and the blow valve 15b are turned on (the electromagnetic solenoid is energized), both the vacuum valve 15a and the blow valve 15b are in an offset position. At this time, the negative pressure air supplied from the negative pressure source NP is blocked by the vacuum valve 15a, and the positive pressure air supplied from the positive pressure source PP flows into the air pipeline 25 through the blow valve 15b and the vacuum valve 15a. As a result, positive pressure air is supplied to the pad space 23S via the nozzle internal flow path 22L, and blow pressure is generated on the suction pad 23 via the nozzle 22 (see the "Blow" section in Figure 5).

[0023] Furthermore, when the vacuum valve 15a is ON and the blow valve 15b is OFF, the vacuum valve 15a is in the offset position and the blow valve 15b is in the normal position. In this state, the negative pressure air supplied from the negative pressure source NP is blocked by the vacuum valve 15a, and the positive pressure air supplied from the positive pressure source PP is also blocked by the blow valve 15b. In this state, the air pipeline 25 is connected to the atmospheric pressure opening passage AL through the vacuum valve 15a and the blow valve 15b, so the space inside the pad 23S is open to the atmosphere via the nozzle 22 (see the "Open to the Atmosphere" section in Figure 5).

[0024] In this embodiment, the pressure in the pad cavity 23S can be switched between negative pressure, positive pressure, and atmospheric pressure by switching the positions of the vacuum valve 15a and the blow valve 15b.

[0025] In Figure 1, a dummy component DBH is placed on the dummy component mounting section 17. The dummy component DBH is a replica (imitation) of component BH mounted on the circuit board KB. The dummy component DBH has the same shape and size as component BH, but its weight exceeds that of component BH mounted on the circuit board KB. In other words, in this embodiment, the dummy component DBH (dummy workpiece) has a weight that exceeds that of component BH (workpiece).

[0026] In Figure 1, a replacement suction part 24 (a new suction part 24) is placed on the replacement stand 18. The replacement stand 18 has a configuration similar to that of a nozzle replacement stand commonly known as a "nozzle changer," and as shown below, it is configured so that the suction part 24 can be removed from the lifting shaft 21 in the same manner as removing the nozzle 22 from the lifting shaft 21, and the replacement suction part 24 can be attached to the lifting shaft 21 in the same manner as attaching the nozzle 22 to the lifting shaft 21.

[0027] In Figures 6(a), (b) and 7(a), (b), the replacement stand 18 includes a base portion 31 on which the suction component 24 is placed, and a shutter 32 that is slidable horizontally relative to the base portion 31. The base portion 31 is made of a block-shaped member, and on its upper surface there are a plurality of recessed portions 33 that are recessed downwards, arranged in the horizontal X direction and the Y direction which is perpendicular to the X direction in the horizontal plane (i.e., arranged in a matrix) (the vertical direction is the Z direction). The inner diameter d0 of each recessed portion 33 (Figures 6(b) and 7(b)) is larger than the outer diameter d1 of the base portion 23b of the suction pad 23 (Figures 3(a) and 7(b)), and smaller than the outer diameter d2 of the flange portion 22c of the nozzle 22 (Figures 3(a) and 7(b)).

[0028] In Figures 6(a) and 6(b), the shutter 32 is made of a rectangular flat plate-shaped member and has a plurality of shutter grooves 34 extending in the X direction. The groove width 34W of the shutter grooves 34 (Figure 6(a)) is larger than the outer diameter d3 of the base 22a of the nozzle 22 (Figures 3(b) and 7(b)) and smaller than the outer diameter d2 of the flange portion 22c of the nozzle 22.

[0029] In Figures 6(a) and 6(b), the shutter groove 34 has a plurality (four in this case) of relief holes 35, each having an inner diameter larger than the groove width 34W of the shutter groove 34. The arrangement of the relief holes 35 coincides with the arrangement of the recessed portions 33. The inner diameter of each relief hole 35 is larger than the outer diameter d2 of the flange portion 22c of the nozzle 22.

[0030] The shutter 32 can be positioned in either a closed position (as shown in Figures 6(a) and 7(a)) or an open position (as shown in Figures 6(b) and 7(b)) by sliding in the X direction relative to the base portion 31. The amount of movement DL (Figure 6(b)) between the open and closed positions is set to half the distance of the pitch spacing PC (as shown in Figures 6(a) and 7(a)) of the recessed portions 33 aligned in the X direction.

[0031] In Figures 6(a) and 6(b), a cylinder 36 with a piston rod 36R facing in the X direction is attached to the base portion 31. The piston rod 36R is connected to a connecting piece 32H provided on the shutter 32, and when the cylinder 36 acts on the piston rod 36R, the shutter 32 slides in the X direction. In this embodiment, the shutter 32 is in the closed position when the cylinder 36 advances the piston rod 36R (Figures 6(a) and 7(a)), and is in the closed position when the cylinder 36 retracts the piston rod 36R (Figures 6(b) and 7(b)).

[0032] When the shutter 32 is in the closed position (Figures 6(a) and 7(a)), the center of each relief hole 35 formed in the shutter 32 is located, in a plan view, at a position offset by half a pitch of the pitch spacing PC from the center of the recessed portion 33. Therefore, when a suction component 24 is placed in the recessed portion 33, a portion of the flange portion 22c of the nozzle 22 of the suction component 24 is covered by the shutter 32 (Figures 6(a) and 7(a)), and it is not possible to pull up the suction component 24 through the relief hole 35. Furthermore, it is not possible to place other suction components 24 in the recessed portion 33 through the relief hole 35. In other words, when the shutter 32 is in the closed position, it is impossible to pull up or place suction components 24 on the recessed portion 33.

[0033] When the shutter 32 is in the open position (Figures 6(b) and 7(b)), the center of the relief hole 35 formed in the shutter 32 and the center of the recess 33 are aligned in a plan view. Therefore, a portion of the flange 22c of the nozzle 22 placed in the recess 33 is not covered by the shutter 32 (Figures 6(b) and 7(b)), and it is possible to pull up the suction component 24 through the relief hole 35. In addition, other suction components 24 can be placed in the recess 33 through the relief hole 35. In other words, when the shutter 32 is in the open position, it is possible to pull up and place the nozzle 22 in relation to the recess 33.

[0034] In Figure 8, the control unit 40 (see also Figure 1) of the component mounting device 10 controls the substrate positioning unit 11, the lifting unit 13L of the head unit 13, the head unit moving mechanism 14, and the valve unit 15. Specifically, the control unit 40 controls the substrate positioning unit 11 to transport and position the substrate KB, and controls the head unit moving mechanism 14 to move the head unit 13. The control unit 40 also controls the lifting unit 13L to raise and lower the lifting shaft 21 (i.e., the suction component 24), and controls the vacuum valve 15a and blow valve 15b that constitute the valve unit 15 (power supply control to the electromagnetic solenoid), thereby generating suction pressure or blow pressure in the pad internal space 23S, or opening the pad internal space 23S to the atmosphere.

[0035] In Figures 1 and 8, a touch panel 40T is connected to the control unit 40. The operator can input the necessary information into the control unit 40 by operating the touch panel 40T. The operator can also receive necessary information from the control unit 40 through the touch panel 40T.

[0036] In Figure 8, the control unit 40 comprises an operation control unit 41, a storage unit 42, a judgment unit 43, a counting unit 44, a determination unit 45, and a replacement control unit 46. The operation control unit 41 controls the movement of the head unit 13 by the head unit movement mechanism 14, the lifting and lowering of the lifting shaft 21 (i.e., the suction component 24) by the lifting unit 13L, and the generation of suction pressure or blow pressure on the suction pad 23 by the valve unit 15. The storage unit 42 stores a mounting work program that records the operation procedures of each part for the component mounting device 10 to perform component mounting work, as well as an inspection work program for performing the suction pad inspection work described later. The storage unit 42 also stores various data related to the substrate KB and component BH required for component mounting work, as well as various data required for suction pad inspection work (such as threshold data described later).

[0037] The judgment unit 43 makes the necessary judgments during the suction pad inspection process. The counting unit 44 counts the number of consecutive repetitions of the judgment made by the judgment unit 43. The determination unit 45 determines whether the suction pad 23 is good or bad based on the results determined by the judgment unit 43.

[0038] When the determination unit 45 determines that the suction pad 23 is defective, the replacement control unit 46 controls each part so that the defective suction pad 23 is removed from the head unit 13, and then a replacement suction pad 23 provided on the replacement stand 18 is attached to the head unit 13.

[0039] When the component mounting device 10 performs component mounting work, first the control unit 40 activates the substrate positioning unit 11 to receive the substrate KB sent from the upstream device of the component mounting device 10 and position it at a predetermined work position.

[0040] Once the circuit board KB is positioned in the working position, the control unit 40 activates the head unit movement mechanism 14 to repeatedly perform mounting turns on the head unit 13. In one mounting turn, the head unit 13 moves above the component supply unit 12 to pick up the component BH supplied by the component supply unit 12 by picking it up with the suction pad 23, and after the pickup operation, moves above the circuit board KB to release the component BH from the suction pad 23 and mount the component BH onto the circuit board KB.

[0041] The component mounting device 10 repeatedly performs mounting turns with the head unit 13 to mount the components BH to be mounted on the substrate KB, and then operates the substrate positioning unit 11 to transport the substrate KB downstream. This completes the component mounting work for one substrate KB.

[0042] Here, during the mounting turn described above, when the control unit 40 picks up the component BH supplied by the component supply unit 12 onto the head unit 13, it turns on both the vacuum valve 15a and the blow valve 15b while the suction pad 23 is in contact with the component BH, thereby generating suction pressure in the pad's internal space 23S through the nozzle 22 (Figure 9(a)). Furthermore, when the picked-up component BH is detached from the suction pad 23 and mounted onto the substrate KB, it switches both the vacuum valve 15a and the blow valve 15b on, thereby generating blow pressure in the pad's internal space 23S through the nozzle 22 (Figure 9(b)). After the component BH is mounted onto the substrate KB, it switches only the blow valve 15b off, thereby releasing the pad's internal space 23S to the atmosphere through the nozzle 22 (Figure 9(c)).

[0043] As described above, the component mounting device 10 in this embodiment is configured to include a head unit 13 that sucks air through a nozzle 22 connected to the suction pad 23 while the suction pad 23 is in contact with the component BH, thereby lifting the component BH that has been picked up by the suction pad 23 and transferring it to a predetermined location on the substrate KB.

[0044] As mentioned above, the flow sensor 16 measures the flow rate of air flowing through the nozzle 22. Therefore, the control unit 40 can determine whether or not the suction pad 23 has picked up the part BH based on the detection information from the flow sensor 16. Specifically, when the control unit 40 causes the suction pad 23 to pick up the part BH by putting the nozzle 22 into a "suction" state, if the flow rate of air in the nozzle 22 measured by the flow sensor 16 is below a specified threshold (no air is flowing), the determination unit 43 determines that the suction pad 23 has picked up the part BH. On the other hand, if the flow rate of air in the nozzle 22 measured by the flow sensor 16 exceeds a specified threshold (air is flowing), the determination unit 43 determines that the suction pad 23 has not picked up the part BH.

[0045] As described above, the component mounting device 10 can adsorb component BH by supplying negative pressure air to the air pipeline 25. However, if the bottom portion 23b of the suction pad 23 is warped or cracked, air leakage occurs between the suction pad 23 and the component BH. As a result, a negative pressure level sufficient to adsorb the component BH cannot be secured by the suction pad 23, and the component BH cannot be lifted, leading to a so-called adsorption error.

[0046] In this embodiment, to prevent the above-mentioned suction errors from occurring during component mounting, a suction pad inspection is performed before the component mounting operation or during maintenance to detect in advance any defects in the suction pad 23. The suction pad inspection procedure will be described below.

[0047] When the component mounting device 10 performs a suction pad inspection, it first brings the lower end surface 23M of the suction pad 23 into contact with the dummy component DBH placed on the dummy component mounting section 17. Then, while in this state, it attempts to lift (pick up) the dummy component DBH by raising the lifting shaft 21 while sucking the air between the suction pad 23 and the dummy component DBH (air in the pad's internal space 23S) through the nozzle 22 (lifting attempt step). While attempting to lift the dummy component DBH in this way, the flow rate of the air flowing through the air pipeline 25 is measured by the flow sensor 16 (flow rate measurement step).

[0048] In the pickup trial process described above, if the suction pad 23 is in good condition without any "sagging" or "cracks," the degree of contact between the lower end surface 23M of the suction pad 23 and the upper surface of the dummy part DBH is high, and no air leakage occurs between the suction pad 23 and the part BH. In such a situation, the negative pressure level in the pad's internal space 23S is high, and the air flow rate (measured value) in the nozzle 22 measured by the flow sensor 16 is below a specified threshold (measured value ≤ threshold).

[0049] In this situation, when the lifting shaft 21 rises, the dummy part DBH moves away from the dummy part mounting section 17, and the dummy part DBH is picked up by the nozzle 22 via the suction pad 23 (Figure 10(a) → Figure 10(b)). In this case, the control unit 40 determines in the judgment unit 43 that the suction pad 23 is holding the dummy part DBH based on the fact that the measured value of the flow sensor 16 is "measured value ≤ threshold" (determination step), and the determination unit 45 determines that the suction pad 23 is in good condition (determination step). The determination result (that the suction pad 23 is in good condition) is then displayed on the touch panel 40T to inform the operator.

[0050] On the other hand, if the suction pad 23 is in a defective state such as "sagging" or "cracked" during the pickup trial process described above, the degree of contact between the lower end surface 23M of the suction pad 23 and the upper surface of the dummy part DBH will not be high, and air leakage will occur between the suction pad 23 and the part BH. In such a situation, the negative pressure level in the pad's internal space 23S will be low, and the air flow rate (measured value) in the nozzle 22 measured by the flow sensor 16 will exceed a specified threshold value (measured value > threshold).

[0051] In this situation, even if the lifting shaft 21 rises, the dummy part DBH does not separate from the dummy part mounting section 17, and the dummy part DBH is not picked up by the nozzle 22 via the suction pad 23 (Figure 11(a) → Figure 11(b)). In this case, the control unit 40 determines in the judgment unit 43 that the suction pad 23 is not adsorbing the dummy part DBH based on the fact that the measured value of the flow sensor 16 is "measured value > threshold" (judgment step), and the determination unit 45 determines that the suction pad 23 is in a defective state (determination step). The determination result (that the suction pad 23 is in a defective state) is then displayed on the touch panel 40T to inform the operator.

[0052] Here, if the control unit 40 determines in the determination unit 45 that "the suction pad 23 is in a defective state," the replacement control unit 46 of the control unit 40 controls the head unit 13 to replace the suction component 24 equipped with the suction pad 23 that has been determined to be in a defective state with a replacement (new) suction component 24 provided on the replacement stand 18. This resolves the defective state of the suction pad 23 of the suction component 24 attached to the lifting shaft 21, and prevents the occurrence of pickup errors of component BH caused by the defective state of the suction pad 23.

[0053] Figure 12 is a flowchart showing the flow of the suction pad inspection process for determining the quality of the suction pad 23 provided by the component mounting device 10. When the control unit 40 receives an inspection start command sent via the touch panel 40T (or from a higher-level device) (step ST1), it controls the head unit movement mechanism 14 from the operation control unit 41 and moves the head unit 13 to position the suction pad 23 above the dummy component DBH (step ST2).

[0054] The control unit 40 positions the suction pad 23 above the dummy part DBH, then lowers the lifting shaft 21 to bring the suction pad 23 into contact with the dummy part DBH (step ST3). Then, it controls the valve unit 15 to supply negative pressure air to the air line 25, generating suction pressure at the lower end of the nozzle 22, thereby drawing the dummy part DBH into the nozzle 22 via the suction pad 23 (step ST4. Figure 13(a)).

[0055] In step ST4, the control unit 40 causes the nozzle 22 to suck in the dummy part DBH, then activates the lifting unit 13L to raise the lifting shaft 21 (i.e., the suction pad 23) (step ST5). The flow rate sensor 16 then measures the flow rate of the air flowing through the nozzle 22 (step ST6). If the air flow rate measured by the flow rate sensor 16 is below a threshold stored in the memory unit 42 ("Y" in step ST7), the control unit 40 determines in the judgment unit 43 that the suction pad 23 is holding the dummy part DBH (step ST8). At this point, the dummy part DBH is actually being lifted by the suction pad 23 (Figure 13(b)).

[0056] If the control unit 40 determines in the determination unit 43 that the suction pad 23 is holding the dummy part DBH, it operates the lifting unit 13L to lower the nozzle 22 (i.e., the suction pad 23) and places the dummy part DBH on the dummy part placement unit 17 (step ST9). Then, it operates the valve unit 15 to put the nozzle 22 into an air-blowing state and release the dummy part DBH from the suction state of the suction pad 23 (step ST10).

[0057] After releasing the dummy part DBH from the suction state, the control unit 40 determines whether the series of steps consisting of steps ST3 to ST10 (referred to as the "inspection process") has been executed a predetermined number of times (for example, 3 times) consecutively (step ST11). If the inspection process has not been executed a predetermined number of times consecutively ("N" in step ST11), the control unit returns to step ST3 and executes the inspection process. On the other hand, if the inspection process has been executed a predetermined number of times consecutively, the control unit 40 determines in the determination unit 45 that the suction pad 23 is in good condition (step ST12). The control unit then displays this information on the touch panel 40T and terminates the suction pad inspection operation.

[0058] In contrast, in step ST7, if the air flow rate measured by the flow sensor 16 exceeds the threshold value stored in the memory unit 42 ("N" in step ST7), the control unit 40 determines in the judgment unit 43 that the suction pad 23 is not adsorbing the dummy part DBH (step ST13). In this state, the dummy part DBH is not actually lifted and remains placed on the dummy part mounting unit 17 (Figure 13(c)). If the control unit 40 determines in the judgment unit 43 that the suction pad 23 is not adsorbing the dummy part DBH, the determination unit 45 determines that the suction pad 23 is defective (step ST14) and displays this information on the touch panel 40T.

[0059] If the determination unit 45 determines that the suction pad 23 is defective, the control unit 40 replaces the defective suction pad 23 with a replacement (new) suction pad 23 (step ST15). Specifically, the replacement control unit 46 of the control unit 40 controls the removal of the defective suction pad 23 from the head unit 13 and the attachment of the replacement suction pad 23 provided on the replacement stand 18 to the head unit 13.

[0060] In detail, first, as shown in Figure 14(a), the suction component 24 equipped with the defective suction pad 23 (referred to as "defective suction component 24," also denoted as "24F") is positioned above the recess 33 where a replacement new suction component 24 (referred to as "new suction component 24," also denoted as "24S") is not placed, and the shutter 32 is set to the open position. Then, the lifting shaft 21 is lowered by the lifting unit 13L (arrow A shown in Figure 14(a)) and the defective suction component 24 is placed in the recess 33 (Figure 14(a)). Once the defective suction component 24 is placed in the recess 33, the shutter 32 is moved to the closed position (arrow B shown in Figure 14(b)), and the lifting shaft 21 is raised (arrow C shown in Figure 14(b)). This removes the defective suction component 24 from the lifting shaft 21 (Figure 14(b)).

[0061] Once the defective suction part 24 is removed from the lifting shaft 21 as described above, the control unit 40 moves the head unit 13 to position the lifting shaft 21 above the new suction part 24 (arrow D in Figure 14(c)). Once the lifting shaft 21 is positioned above the new suction part 24, the control unit 40 lowers the lifting shaft 21 using the lifting unit 13L (arrow E in Figure 14(c)) and inserts the lower end of the lifting shaft 21 into the cylindrical hole 22T of the base 22a of the nozzle 22 of the new suction part 24 (Figure 14(c)). Then, after moving the shutter 32 to the open position (arrow F in Figure 14(d)), the lifting shaft 21 is raised (arrow G in Figure 14(d)). This results in the new suction part 24 being attached to the lifting shaft 21 (Figure 14(d)).

[0062] As described above, the component mounting device 10 of this embodiment comprises a dummy component DBH that mimics the workpiece component BH, a lifting unit 13L which serves as a lifting trial means that attempts to lift the dummy component DBH by sucking air through a nozzle 22 while the suction pad 23 is in contact with the dummy component DBH, a flow sensor 16 which serves as a flow rate measuring unit that measures the flow rate of air flowing through the nozzle 22 while the lifting unit 13L is attempting to lift the dummy component DBH, a determination unit 43 which determines whether or not the suction pad 23 is adsorbing the dummy component DBH based on the flow rate of air measured by the flow sensor 16, and a determination unit 45 which determines the quality of the suction pad 23 based on the determination result by the determination unit 43.

[0063] Furthermore, the suction pad inspection method in the component mounting device 10 in this embodiment includes a lifting trial step (steps ST3 to ST5) in which air is sucked through the nozzle 22 while the suction pad 23 is in contact with the dummy component DBH, and an attempt is made to lift the dummy component DBH; a flow rate measurement step (step ST6) in which the flow rate of air flowing through the nozzle 22 is measured while an attempt is being made to lift the dummy component DBH in the lifting trial step; a determination step (steps ST7, ST8, and ST13) in which it is determined whether or not the suction pad 23 is adsorbing the dummy component DBH based on the flow rate of air measured in the flow rate measurement step; and a determination step (step ST12 or ST14) in which the quality of the suction pad 23 is determined based on the determination result in the determination step.

[0064] In the component mounting device 10 (suction pad inspection method) of this embodiment, instead of actually suctioning the component BH itself (which is to be mounted on the substrate KB), the suction pad 23 is used to actually suction a dummy component DBH, which is a replica of the component BH, to determine whether the suction pad 23 is defective or not. This allows for the detection of a defective suction pad 23 in advance, either before production starts or during periodic maintenance, and enables necessary corrective action (for example, replacing the suction component 24 with a new one). Thus, this embodiment prevents situations where the suction pad 23 becomes defective during production, forcing the device to stop operating to replace the suction pad 23 and reducing the productivity of the component mounting device 10. In other words, the component mounting device 10 (suction pad inspection method) of this embodiment allows for the detection of a defective suction pad 23 in advance, preventing a decrease in productivity and equipment shutdown.

[0065] In this embodiment, as described above, the dummy component DBH has a weight greater than the actual component BH mounted on the substrate KB. Therefore, a defective suction pad 23 is detected under stricter conditions than when the weight of the dummy component DBH is the same as the weight of component BH. As a result, suction pads 23 that are on the verge of becoming defective due to deterioration over time are also excluded as defective, thereby improving the quality level of the suction pads 23.

[0066] Furthermore, as shown in the modified example of the dummy part DBH in Figure 15, if the contact surface DM that contacts the suction pad 23 has an uneven shape, it is possible to intentionally create a slight air leak between the suction pad 23 and the dummy part DBH. This allows for the detection of defects in the suction pad 23 under stricter conditions, thereby improving the quality level of the suction pad 23.

[0067] Furthermore, the component mounting device 10 in this embodiment includes a replacement stand 18 equipped with a replacement suction component 24 (i.e., a replacement suction pad 23), and when the determination unit 45 determines that the suction pad 23 is defective, the defective suction pad 23 is removed from the head unit 13 and the replacement suction component 24 provided on the replacement stand 18 is attached to the head unit 13. The suction pad inspection method in the component mounting device 10 in this embodiment includes a replacement step (step ST15) in which, if the suction pad 23 is determined to be defective in the determination step (step ST12 or step ST14), the defective suction pad 23 is removed from the head unit 13 and a replacement suction pad 23 is attached to the head unit 13. Therefore, even if there is a suction pad 23 that is determined to be defective, it can be quickly and automatically replaced with a replacement (new) suction pad 23, thereby reducing the time required to replace the suction pad 23.

[0068] The embodiments of this disclosure are described above, and include the following technologies (workpiece transfer device and suction pad inspection method).

[0069] (Item 1) A workpiece transfer device (parts mounting device 10) comprising a head unit (head unit 13) that sucks air through a nozzle (nozzle 22) connected to a suction pad (suction pad 23) while the suction pad is in contact with a workpiece (parts BH), thereby lifting the workpiece that has been sucked onto the suction pad and transferring it to a predetermined location, the workpiece transfer device comprising: a dummy workpiece (dummy parts DBH) that mimics the workpiece; a lifting trial means (lifting unit 13L) that sucks air through the nozzle while the suction pad is in contact with the dummy workpiece and attempts to lift the dummy workpiece in that state; a flow meter side unit (flow sensor 16) that measures the flow rate of air flowing through the nozzle while the lifting of the dummy workpiece is being attempted; a determination unit (determination unit 43) that determines whether or not the suction pad is sucking onto the dummy workpiece based on the flow rate of air measured by the flow meter side unit; and a determination unit (determination unit 45) that determines the quality of the suction pad based on the determination result by the determination unit.

[0070] In the workpiece transfer device described in item 1, the suction pad is used to determine whether it is defective or not by actually trying to pick up a dummy workpiece, which is a replica of the workpiece, rather than the actual workpiece itself. This allows for the detection of defective suction pads in advance, such as before production starts or during periodic maintenance, and enables necessary corrective action. Thus, it is possible to prevent situations where a suction pad becomes defective during production, forcing the device to shut down for replacement and reducing the productivity of the workpiece transfer device. In other words, the workpiece transfer device described in item 1 allows for the detection of defective suction pads in advance, preventing productivity losses and equipment shutdowns.

[0071] (Item 2) The workpiece transfer device according to item 1, wherein the dummy workpiece has a weight exceeding the weight of the workpiece.

[0072] According to the technology in item 2, defects in the suction pads are detected under stricter conditions than when the weight of the dummy workpiece is the same as the weight of the workpiece. As a result, suction pads that are on the verge of becoming defective due to aging are also excluded as defective, thereby improving the quality level of the suction pads.

[0073] (Item 3) The workpiece transfer device according to item 1, wherein the contact surface of the dummy workpiece that contacts the suction pad has an uneven shape.

[0074] According to the technology described in item 3, a slight air leak can be intentionally created between the suction pad and the dummy workpiece. This allows for the detection of defects in the suction pad under more stringent conditions, thereby improving the quality level of the suction pad.

[0075] (Item 4) The workpiece transfer device according to item 1, comprising a replacement stand (replacement stand 18) equipped with a replacement suction pad, wherein when the determination unit determines that the suction pad is defective, the device operates to remove the defective suction pad from the head unit and attach the replacement suction pad provided on the replacement stand to the head unit.

[0076] According to the technology described in item 4, even if a suction pad is determined to be defective, it can be quickly and automatically replaced with a replacement (new) suction pad, thereby reducing the time required for suction pad replacement.

[0077] (Item 5) The workpiece transfer device according to item 1, wherein the workpiece is a component (component BH) mounted on a substrate (substrate KB), and the head unit transfers the component to the substrate by adsorbing it onto the suction pad.

[0078] According to the technology in item 5, the effects of item 1 can be obtained in component mounting equipment.

[0079] (Item 6) A method for inspecting a suction pad in a workpiece transfer device, comprising a head unit that sucks air through a nozzle connected to the suction pad while the suction pad is in contact with a workpiece, thereby lifting the workpiece that has been sucked onto the suction pad and transferring it to a predetermined location, the method comprising: a lifting trial step (steps ST3 to ST5) in which air is sucked through the nozzle while the suction pad is in contact with a dummy workpiece that mimics the workpiece, and an attempt is made to lift the dummy workpiece in that state; a flow rate measurement step (step ST6) in which the flow rate of air flowing through the nozzle is measured while the lifting of the dummy workpiece is being attempted; a determination step (steps ST7, ST8, and ST13) in which it is determined whether or not the suction pad is sucking onto the dummy workpiece based on the flow rate of air measured in the flow rate measurement step; and a determination step (step ST12 or ST14) in which the quality of the suction pad is determined based on the determination result in the determination step.

[0080] The suction pad inspection method in item 6, similar to the effect of the technology in item 1, allows for the detection of defective suction pads in advance, either before production starts or during periodic maintenance, enabling necessary corrective action. Therefore, it is possible to prevent situations where a suction pad becomes defective during production, forcing the equipment to shut down for replacement and reducing the productivity of the workpiece transfer device. In other words, the suction pad inspection method in item 6 allows for the detection of defective suction pads in advance, preventing productivity losses and equipment shutdowns.

[0081] (Item 7) The suction pad inspection method according to item 6, wherein the dummy workpiece has a weight greater than the weight of the workpiece.

[0082] According to the technology in item 7, similar to the effect of the technology in item 2, defects in the suction pad are detected under stricter conditions than when the weight of the dummy workpiece is the same as the weight of the workpiece. Therefore, suction pads that are on the verge of becoming defective due to deterioration over time are also excluded as defective, thereby improving the quality level of the suction pads.

[0083] (Item 8) The suction pad inspection method according to item 6, wherein the contact surface of the dummy workpiece that contacts the suction pad has an uneven shape.

[0084] According to the technology in item 8, similar to the effect of the technology in item 3, it is possible to intentionally create a slight air leak between the suction pad and the dummy workpiece. This allows for the detection of defects in the suction pad under more stringent conditions, thereby improving the quality level of the suction pad.

[0085] (Item 9) The suction pad inspection method according to claim 6, further comprising a replacement step of removing the defective suction pad from the head and attaching a replacement suction pad to the head if the suction pad is determined to be defective in the determination step.

[0086] According to the technology in item 9, similar to the effect of the technology in item 4, even if a suction pad is determined to be defective, that defective suction pad can be quickly and automatically replaced with a replacement (new) suction pad, thereby reducing the time required for suction pad replacement.

[0087] (Item 10) The suction pad inspection method according to item 6, wherein the workpiece is a component mounted on a substrate, and the head unit picks up the component with the suction pad and transfers it to the substrate.

[0088] According to the technology of item 10, the effects of item 6 can be obtained in component mounting equipment.

[0089] While embodiments of this disclosure have been described so far, the technology of this disclosure is not limited to those described above, and various modifications are possible. For example, in the embodiments described above, the dummy component DBH was made to have a weight greater than the weight of component BH mounted on the substrate KB, but at a minimum, it only needs to have the same weight as component BH.

[0090] Furthermore, in the above implementation, the suction pad 23 was determined to be in good condition only after the inspection process consisting of steps ST3 to ST10 could be performed consecutively a predetermined number of times. However, this is optional, and the suction pad 23 may be determined to be in good condition after the inspection process has been performed just once.

[0091] Furthermore, although the above-described embodiment shows an example where the workpiece transfer device is a component mounting device, the workpiece transfer device can be any device that sucks air through a nozzle connected to the suction pad while the suction pad is in contact with the workpiece, thereby lifting the workpiece that has been picked up by the suction pad and transferring it to a predetermined location. Therefore, it does not necessarily have to be a component mounting device, and it can also be a workpiece transfer device that simply moves other items (workpieces) to a predetermined location. [Industrial applicability]

[0092] This invention provides a workpiece transfer device and a suction pad inspection method that can detect defects in the suction pad in advance, thereby preventing a decrease in productivity and equipment downtime. [Explanation of Symbols]

[0093] 10. Parts mounting device (workpiece transfer device) 11 Substrate positioning section 12. Parts Supply Department 13 Head section 13L Lifting section (lifting trial means) 15 Valve Unit 16. Flow sensor (side of flow meter) 17 Dummy parts mounting section 18 Switchboard 21 Lifting shaft 21L shaft internal flow path 22 nozzles 22L nozzle internal flow path 22b Main body 22c Tsubabe 22T Cylindrical bore 23 Suction pads 23b Hem 23M Bottom end surface 23S Pad interior space 24 Suction components 25 Air piping 31 Base section 32 shutters 35 escape holes 40 Control Unit 43 Judgment Department 44 Count section 45 Judgment section 46 Exchange Control Unit 40T Touch Panel BH parts (workpieces) DBH Dummy Parts (Dummy Workpieces) DM contact surface KB board

Claims

1. A workpiece transfer device comprising a head unit that sucks air through a nozzle connected to a suction pad while the suction pad is in contact with the workpiece, thereby lifting the workpiece that has been adsorbed onto the suction pad and transferring it to a predetermined location, A dummy workpiece that imitates the aforementioned workpiece, A lifting trial means for attempting to lift the dummy workpiece by sucking air through the nozzle while the suction pad is in contact with the dummy workpiece, A flow meter side unit for measuring the flow rate of air flowing through the nozzle while attempting to lift the dummy workpiece, A determination unit that determines whether or not the suction pad is adsorbing the dummy workpiece based on the air flow rate measured by the flow meter side, A determination unit that determines whether the suction pad is good or bad based on the determination result by the determination unit, A workpiece transfer device equipped with this device.

2. The workpiece transfer device according to claim 1, wherein the dummy workpiece has a weight exceeding the weight of the workpiece.

3. The workpiece transfer device according to claim 1, wherein the contact surface of the dummy workpiece that contacts the suction pad has an uneven shape.

4. The workpiece transfer device according to claim 1, comprising a replacement stand equipped with a replacement suction pad, wherein when the determination unit determines that the suction pad is defective, the device operates to remove the defective suction pad from the head unit and attach the replacement suction pad provided on the replacement stand to the head unit.

5. The workpiece transfer device according to claim 1, wherein the workpiece is a component mounted on a substrate, and the head portion transfers the component to the substrate by adsorbing it onto the suction pad.

6. A method for inspecting a suction pad in a workpiece transfer device, which includes a head unit that sucks air through a nozzle connected to the suction pad while the suction pad is in contact with the workpiece, thereby lifting the workpiece that has been sucked onto the suction pad and transferring it to a predetermined location, A lifting trial step involves bringing the suction pad into contact with a dummy workpiece that mimics the aforementioned workpiece, sucking air through the nozzle, and attempting to lift the dummy workpiece in that state. A flow rate measurement step is performed to measure the flow rate of air flowing through the nozzle while the dummy workpiece is being attempted to be lifted. A determination step in which, based on the flow rate of air measured in the flow rate measurement step, determines whether or not the suction pad is adsorbing the dummy workpiece, A determination step in which the quality of the suction pad is determined based on the determination result in the aforementioned determination step, A method for inspecting suction pads.

7. The suction pad inspection method according to claim 6, wherein the dummy workpiece has a weight exceeding the weight of the workpiece.

8. The suction pad inspection method according to claim 6, wherein the contact surface of the dummy workpiece that contacts the suction pad has an uneven shape.

9. The suction pad inspection method according to claim 6, further comprising a replacement step of removing the defective suction pad from the head and attaching a replacement suction pad to the head if the suction pad is determined to be defective in the determination step.

10. The suction pad inspection method according to claim 6, wherein the workpiece is a component mounted on a substrate, and the head unit picks up the component with the suction pad and transfers it to the substrate.

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