Component mounting apparatus and method of inspecting mounting head

Abstract

To provide a component mounting device and an inspection method of a mounting head capable of easily and quickly inspecting a belt provided in the mounting head.SOLUTION: After a load acting on a motor 33 is detected while the motor 33 is operated by a motor driver 51 under a predetermined inspection time operation condition (ST1 and ST2. The load factor μ of the motor 33 is calculated based on the detected load (ST3 and ST4. The state of the belt 44 is determined based on the calculated load factor μ (ST5 to ST9). Determination step).SELECTED DRAWING: Figure 9

Description

[Technical Field]

[0001] The present disclosure relates to a component mounting device that uses a nozzle provided in a mounting head to pick up components and mount them on a board, and a method for inspecting the mounting head. [Background technology]

[0002] Conventionally, component mounting devices for mounting components onto a circuit board have a mounting head with a component suction nozzle attached to the lower end of a shaft member, and the mounting head picks up the component and mounts it on the circuit board. A servo-controlled motor shaft and the shaft member are connected by a belt, and the rotation of the motor shaft is transmitted to the shaft member through the tension of the belt, so that the nozzle is positioned at a desired rotational position (for example, see Patent Document 1 below). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2024-36731 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the belts in the mounting heads described above tend to become increasingly elongated over time due to aging. This can cause the rotation of the motor shaft to be inaccurately transmitted to the shaft, reducing the precision of the shaft (i.e., nozzle) rotation control, potentially resulting in the production of defective circuit boards. For this reason, conventionally, workers would periodically measure the belt tension using a dedicated device such as an ultrasonic belt tension meter, and occasionally inspect the belt to see if it was time for maintenance, such as replacement or cleaning. However, this process was extremely tedious and time-consuming.

[0005] Therefore, an object of the present disclosure is to provide a component mounting device and a mounting head inspection method that can easily and quickly inspect a belt provided in a mounting head. [Means for solving the problem]

[0006] The component mounting device disclosed herein is a component mounting device that mounts components onto a substrate using a mounting head having a nozzle that suctions components, a shaft member with the nozzle at its lower end, a motor with a motor shaft, and a belt that transmits the rotation of the motor shaft to the shaft member, and is equipped with a motor driver that operates the motor under predetermined inspection operating conditions, a load detection unit that detects the load acting on the motor while the motor is operating under the inspection operating conditions, a load factor calculation unit that calculates the load factor of the motor based on the load detected by the load detection unit, and a determination unit that determines the state of the belt based on the load factor calculated by the load factor calculation unit.

[0007] The mounting head inspection method disclosed herein is a method for inspecting a mounting head in a component mounting device that mounts components on a board using a mounting head having a nozzle that picks up components, a shaft member with the nozzle at its lower end, a motor with a motor shaft, and a belt that transmits rotation of the motor shaft to the shaft member, and includes a load detection step of operating the motor under specified inspection operating conditions and detecting the load acting on the motor during that time, a load factor calculation step of calculating a load factor of the motor based on the load detected in the load detection step, and a determination step of determining the condition of the belt based on the calculated load factor. [Effects of the Invention]

[0008] According to the present disclosure, the belt provided on the mounting head can be inspected simply and quickly. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a perspective view of a component mounting device according to an embodiment of the present disclosure. [Figure 2] FIG. 2 is a partial perspective view of a mounting head included in the component mounting device according to the embodiment of the present disclosure. [Figure 3] FIG. 2 is a block diagram showing a control system of the component mounting device according to the embodiment of the present disclosure. [Figure 4] FIG. 2 is a cross-sectional perspective view of a portion of a mounting head included in the component mounting device according to the embodiment of the present disclosure. [Figure 5] 1 is a simplified plan view showing the arrangement of a motor and a rotation transmission mechanism provided in a mounting head of a component mounting device according to an embodiment of the present disclosure. FIG. [Figure 6] 1 is a schematic side view of a motor and a rotation transmission mechanism provided in a mounting head of a component mounting device according to an embodiment of the present disclosure. FIG. [Figure 7] 10 is a graph showing the relationship between the load factor of a motor included in a component mounting device according to an embodiment of the present disclosure and the elongation and usage time of the belt. [Figure 8] 10A and 10B are diagrams illustrating the relationship between the rotation of a motor and the rotation of a shaft member included in a component mounting device according to an embodiment of the present disclosure. [Figure 9] 1 is a flowchart showing a flow of an inspection performed by a component mounting device according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings. Fig. 1 shows a component mounting device 1 according to one embodiment of the present disclosure. The component mounting device 1 is a device that mounts components BH on a board KB sent from the upstream side and carries it out downstream. For ease of explanation, the transport direction of the board KB in the component mounting device 1 (the left-right direction as seen from the worker OP) is referred to as the X direction, the horizontal direction perpendicular to the X direction (the front-rear direction as seen from the worker OP) is referred to as the Y direction, and the up-down direction is referred to as the Z direction.

[0011] 1, component mounting device 1 includes base 11, conveyor 12, multiple part feeders 13, mounting head 14, head movement mechanism 15, and touch panel 16. Conveyor 12 is provided on base 11, and supports both ends of substrate KB from below, transporting it in the X direction.

[0012] A plurality of part feeders 13 are provided at the Y-direction end of the base 11. The part feeders 13 are, for example, tape feeders. Each part feeder 13 continuously supplies parts BH to a part pick-up position 13T set at the end on the far side (conveyor 12 side) as seen from the operator OP in the Y direction.

[0013] 2, the mounting head 14 has a plurality of (four in this example) shaft members 21 extending downward. A nozzle 22 is attached to the lower end of each shaft member 21. The nozzle 22 is connected to a vacuum source (not shown) through a vacuum supply path formed inside the shaft member 21.

[0014] 1, the head moving mechanism 15 includes a fixed beam 15a that is provided on the base 11 and extends in the Y direction, and a movable beam 15b that is supported at one end by the fixed beam 15a and extends in the X direction. A mounting head 14 is attached to the movable beam 15b. The movable beam 15b is movable in the Y direction along the fixed beam 15a, and the mounting head 14 is movable along the movable beam 15b. The mounting head 14 can move within a horizontal plane (XY plane) by the movement of the movable beam 15b in the Y direction and the movement of the mounting head 14 itself in the X direction.

[0015] 1, the touch panel 16 is provided on the base 11. The touch panel 16 functions as an input device and an output device in the component mounting device 1.

[0016] 3, a control unit 30 provided in the component mounting device 1 controls the operations of the conveyor 12, the component feeders 13, the mounting head 14, and the head moving mechanism 15. The control unit 30 controls the operation of the conveyor 12 to transport the board KB and position it at the work position, and controls the operation of each component feeder 13 to supply components BH to the respective component take-out positions 13T.

[0017] The control unit 30 supplies vacuum pressure into each shaft member 21, thereby generating a suction force for the component BH at the lower end of the nozzle 22 attached to that shaft member 21. The control unit 30 is connected to the touch panel 16, and exchanges information with the operator OP through the touch panel 16.

[0018] When the component mounting device 1 configured as described above performs a component mounting operation of mounting components BH on a board KB, the control unit 30 first operates the conveyor 12 to carry in the board KB supplied from outside the component mounting device 1 and position the board KB at a predetermined work position. After the board KB is positioned, the control unit 30 operates each part feeder 13 to supply components BH to each part take-out position 13T, while operating the head moving mechanism 15 to move the mounting head 14 back and forth between the part feeders 13 and the board KB.

[0019] The mounting head 14 moves back and forth between the parts feeder 13 and the board KB, repeatedly performing a mounting turn consisting of an operation of picking up and sucking up the components BH supplied to the component removal position 13T by the parts feeder 13, and a mounting operation of mounting the picked-up components BH onto the board KB. When the mounting head 14 has repeatedly performed these operations and all the components BH to be mounted on the board KB have been mounted, the control unit 30 operates the conveyor 12 to transport the board KB out of the component mounting device 1. This completes the component mounting operation for one board KB.

[0020] As described above, the component mounting device 1 in this embodiment is configured to mount the component BH on the board KB by the mounting head 14 equipped with the nozzle 22 for suctioning the component BH.

[0021] Next, we will explain the configuration of the mounting head 14 in the component mounting device 1 and its inspection method. As shown in Fig. 2, the mounting head 14 has a base part 31 that holds the four shaft members 21 in a position extending in the Z direction, and four lifting parts 32 that are arranged above the base part 31. Each lifting part 32 is made up of a cylinder or a motor, and lifts and lowers the four shaft members 21 individually relative to the base part 31.

[0022] 2 and 4, a motor 33 and a rotation transmission mechanism 34 are provided inside the base portion 31. The motor 33 has a motor shaft 33J, which is its rotation drive shaft, facing downward.

[0023] The rotation transmission mechanism 34 is a mechanism that transmits the rotation of the motor shaft 33J to the four shaft members 21. As shown in Figures 4 and 5, the rotation transmission mechanism 34 is configured to include a drive pulley 41 provided at the lower end of the motor shaft 33J, a plurality (four in this case) of driven pulleys 42 attached to each of the four shaft members 21, a plurality (three in this case) of idle pulleys 43, and a belt 44. The drive pulley 41, the four driven pulleys 42, and the three idle pulleys 43 are all toothed pulleys, and are located at the same height (in the horizontal plane).

[0024] In Figures 4 and 5, the belt 44 is looped around the drive pulley 41, the first driven pulley 42 (first driven pulley 42a), the first idle pulley 43 (first idle pulley 43a), the second driven pulley 42 (second driven pulley 42b), the third driven pulley 42 (third driven pulley 42c), the second idle pulley 43 (second idle pulley 43b), the fourth driven pulley 42 (fourth driven pulley 42d), and the third idle pulley 43 (third idle pulley 43c) in this order.

[0025] Belt 44 is an endless belt member made of an elastic material such as rubber. Belt 44 is a so-called timing belt that has teeth that engage with teeth formed on the outer peripheries of drive pulley 41, four driven pulleys 42, and three idle pulleys 43.

[0026] Each shaft member 21 and the driven pulley 42 corresponding to that shaft member 21 are connected by spline fitting. Therefore, the lifting unit 32 can lift and lower the shaft member 21 without changing the rotational position of the shaft member 21 (the driven pulley 42).

[0027] 3 and 6, the control unit 30 includes a motor driver 51 that servo-controls the motor 33. When the motor driver 51 servo-controls the motor 33 and rotates the motor shaft 33J, the four driven pulleys 42 and three idle pulleys 43 rotate via the belt 44. At this time, the four driven pulleys 42 and the three idle pulleys 43 each rotate in the same direction as the rotation direction of the motor shaft 33J.

[0028] The four driven pulleys 42 rotate at the same rotational distance via the belt 44. Therefore, when the motor shaft 33J rotates with the part BH held by the nozzle 22, the four shaft members 21 rotate at the same rotational distance in the same direction, and the part BH held by the nozzle 22 rotates at the same rotational distance in the same direction. The radii of the four driven pulleys 42 may be the same or different.

[0029] The motor shaft 33J can be rotated in either the forward or reverse direction. By changing the rotation direction of the motor shaft 33J, it is possible to switch the rotation direction of the four shaft members 21 (i.e., the rotation direction of the nozzles 22 attached to each shaft member 21). In this way, in the first embodiment, a single motor 33 is configured to rotate the multiple shaft members 21 (i.e., the multiple nozzles 22) in the same direction in synchronization via the belt 44.

[0030] As the belt 44 is used for a long time, residual elongation (hereinafter simply referred to as "elongation") due to deterioration over time increases, as shown in the graph of Fig. 7. The elongation of the belt 44 due to deterioration over time can be a factor that prevents the rotation of the motor shaft 33J from being accurately transmitted to the shaft member 21.

[0031] In the component mounting device 1, the accuracy of controlling the rotational position (Θ) of the shaft member 21 by the rotational position of the motor shaft 33J (hereinafter referred to as "Θ accuracy") is related to the elongation of the belt 44, and the greater the elongation of the belt 44, the lower the Θ accuracy. Therefore, as shown in Figure 7, the longer the belt 44 is used and the greater its elongation, the lower the Θ accuracy of the shaft member 21 becomes.

[0032] For this reason, in order to be able to accurately control the rotational position of the shaft member 21 by the rotation of the motor shaft 33J (to maintain a high level of Θ accuracy), it is necessary to check the elongation of the belt 44 due to deterioration over time from time to time, and when the elongation becomes large enough to require maintenance of the belt 44 (maintenance required level), it is necessary to perform maintenance of the belt 44. Here, "maintenance of the belt 44" specifically means replacing the belt 44 with a new one, cleaning it, or adjusting the tension of the belt 44 without removing it.

[0033] As shown in FIGS. 3 and 6 , the control unit 30 includes the motor driver 51, a load detection unit 52, a load factor calculation unit 53, and a determination unit 54. When inspecting the mounting head 14, the motor driver 51 operates (rotates) the motor shaft 33J under predetermined inspection operating conditions. Specifically, the motor driver 51 rotates the motor shaft 33J from a stopped state at an arbitrary stop position NP to a predetermined rotation position Φ with a predetermined speed profile (e.g., a trapezoidal speed profile) (FIGS. 8(a) to 8(b)). When the motor shaft 33J rotates from the stop position NP to the predetermined rotation position Φ, the rotation is transmitted to the shaft member 21 via the tension P of the belt 44, and the shaft member 21 rotates accordingly to a rotation position Θ corresponding to the rotation position Φ of the motor shaft 33J. At this time, the motor shaft 33J receives a load from the shaft member 21 via the belt 44.

[0034] The load detection unit 52 detects the load acting on the motor 33 while the motor 33 is operating under the above-mentioned inspection operating conditions by, for example, monitoring the voltage supplied to the motor 33. Here, the load detected by the load detection unit 52 may include the maximum load acting on the motor 33, the average load during the measurement time, and the main load during the measurement time (for example, the minimum value of the load that accounts for 50% or more of the measurement time).

[0035] The load factor calculation unit 53 calculates the load factor μ of the motor 33 based on the load detected by the load detection unit 52. In detail, the load factor calculation unit 53 calculates the load factor μ (=load / rated load) of the motor 33 by dividing the magnitude of the load detected by the load detection unit 52 by the magnitude of the rated load of the motor 33 stored in advance in a storage unit (not shown) of the control unit 30.

[0036] 7, as the belt 44 is used for a longer period of time and the elongation of the belt 44 increases, the load factor μ of the motor 33 decreases accordingly. Similarly, as the belt 44 is used for a longer period of time and the elongation of the belt 44 increases (as the load factor μ decreases), the Θ accuracy also decreases.

[0037] The determination unit 54 determines the state of the belt 44 based on the load factor μ calculated by the load factor calculation unit 53. In detail, the determination unit 54 compares the calculated load factor μ with a predetermined reference value (first threshold value E1 shown in FIG. 7), and if the load factor μ is lower than the first threshold value E1, determines that the belt 44 is in a state requiring maintenance (a maintenance-required state).

[0038] In this embodiment, as shown in Figure 7, in addition to a first threshold value E1 for determining whether or not the belt 44 is in a state requiring maintenance, a reference value (second threshold value E2) is set for determining whether or not the belt 44 is at a level requiring attention (attention level) but not to the point where maintenance of the belt 44 is required.

[0039] The flowchart in Fig. 9 shows an example of a specific flow of inspecting the mounting head 14 (a method of inspecting the mounting head 14). When inspecting according to this flowchart, the motor driver 51 of the control unit 30 stops the motor shaft 33J (step ST1), and then detects the load acting on the motor 33 while operating the motor shaft 33J under predetermined operating conditions during inspection (operating conditions under which the motor shaft 33J rotates at a predetermined speed profile up to a predetermined rotational position Φ) (Fig. 8(a) → Fig. 8(b)) (step ST2). After detecting the load acting on the motor 33, the load factor calculation unit 53 reads the rated load of the motor 33 from a storage unit (not shown) (step ST3), and calculates the load factor μ of the motor 33 by dividing the load by the rated load (step ST4).

[0040] After the load factor μ of the motor 33 is calculated by the load factor calculation unit 53, the determination unit 54 compares the load factor μ with the second threshold value E2 to check whether the load factor μ is below the second threshold value E2 (step ST5). If the load factor μ is not below the second threshold value E2 (μ≧E2), the determination unit 54 determines that the belt 44 is in a good condition (step ST6).

[0041] In contrast, in step ST5, when the load factor μ calculated in step ST4 is less than the second threshold value E2 (μ < E2), the determination unit 54 compares the load factor μ with the first threshold value E1 and checks whether the load factor μ is less than the first threshold value E1 (step ST7). Then, when the load factor μ is not less than the first threshold value E1 (E1 ≤ load factor μ < E2), it is determined that the belt 44 is in a cautionary state (step ST8).

[0042] On the other hand, in step ST7, when the load factor μ is less than the first threshold value E1 (μ < E1), the determination unit 54 determines that the belt 44 is in a maintenance required state (step ST9). After proceeding to step ST6, step ST8, or step ST9, the determination unit 54 displays the content determined in each step on the touch panel 16 (step ST10). Therefore, the operator OP can grasp the state of the belt 44 without removing it from the mounting head 14. Thus, there is no need to remove the belt 44 from the mounting head 14 until the belt 44 reaches the maintenance required state, and the belt 44 can be removed from the mounting head 14 only after it reaches the maintenance required state.

[0043] As described above, in the component mounting apparatus 1 according to the present embodiment, the motor driver 51 operates the motor 33 under predetermined inspection operation conditions, and the load detection unit 52 detects the load acting on the motor 33 while the motor 33 is operating under the inspection operation conditions. The load factor calculation unit 53 calculates the load factor μ of the motor 33 based on the load detected by the load detection unit 52, and the determination unit 54 determines the state of the belt 44 based on the calculated load factor μ (when the load factor μ is less than the first threshold value E1 which is a predetermined reference value, it is determined that the belt 44 is in a maintenance required state).

[0044] In the method for inspecting the mounting head 14 in this embodiment, the motor driver 51 operates the motor 33 under predetermined inspection operating conditions, and detects the load acting on the motor 33 during that time (steps ST1 and ST2, load detection step), and then calculates the load factor μ of the motor 33 based on the detected load (steps ST3 and ST4, load factor calculation step).Then, the state of the belt 44 is judged based on the calculated load factor μ (steps ST5 to ST9, judgment step).

[0045] In addition, in a configuration in which multiple shaft members 21 are driven to rotate in the same direction in synchronization via belt 44 by one motor 33, as in embodiment 1, the total weight of the multiple shaft members 21 is much greater than the weight of motor shaft 33J, so when servo control of motor 33 is released, only motor shaft 33J is returned, making it easier to obtain accurate judgment results.

[0046] As described above, the component mounting apparatus 1 (method for inspecting the mounting head 14) according to this embodiment allows easy inspection of whether the belt 44 is in a maintenance-requiring state, and does not require a dedicated inspection device (e.g., an ultrasonic belt tension meter), resulting in good workability. Therefore, the component mounting apparatus 1 (method for inspecting the mounting head 14) according to this embodiment allows easy and quick inspection of the belt 44 provided in the mounting head 14. Furthermore, this allows inspection of the belt 44 (calculation of the load factor μ) to be performed in a short time frame unrelated to the production of the board KB itself, such as when component mounting on a certain board KB is completed and the board KB begins to be unloaded, when the next board KB is loaded, or when the board KB is changed model.

[0047] As described above, the Θ accuracy of motor 33 is related to the usage time of belt 44 (FIG. 7), and it is possible to estimate the time Tm when the Θ accuracy will reach a maintenance-requiring level based on the usage time of belt 44. This allows for a timely inspection when the Θ accuracy is likely to reach a maintenance-requiring level by recording the usage time of belt 44 after performing maintenance, without having to perform inspection unnecessarily.

[0048] The first threshold E1 and the second threshold E2 may be fixed values ​​determined at the time of product shipment of the component mounting device 1, or may be variable values ​​that can be changed. For example, a plurality of first thresholds E1 and a plurality of second thresholds E2 may be prepared, and one may be selected and used depending on the usage environment of the belt 44, etc. In this case, the load when a new belt 44 is attached may be stored in the memory of the control unit 30, and the stored load when a new belt 44 is attached may be used as a base for calculating the reference values ​​(first threshold E1 and second threshold E2). Specifically, for example, the load values ​​when the stored reference value gradually decreases at a predetermined rate over time are sequentially set as the first threshold, the second threshold, ...

[0049] As described above, according to the component mounting device 1 (method for inspecting the mounting head 14) of this embodiment, the belt 44 provided on the mounting head 14 can be inspected easily and quickly without the need for dedicated equipment as in the conventional case.

[0050] Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above and various modifications are possible. For example, in the above-described embodiments, the number of shaft members 21 (i.e., the number of nozzles 22) is four, but this is just an example, and the number of shaft members 21 (nozzles 22) is not particularly limited.

[0051] Furthermore, in the above-described embodiment, the load detection unit 52 detects the load acting on the motor 33 by monitoring the voltage supplied to the motor 33, but it may also be configured to detect the load acting on the motor 33 by monitoring the current or power. Furthermore, in the above-described embodiment, the speed profile of the motor shaft 33J when rotating the motor shaft 33J to a predetermined rotation position Φ is exemplified as a trapezoidal speed profile, but the speed profile of the motor shaft 33J in this case is not limited to a trapezoidal speed profile and may be a profile of another shape (for example, a triangular or curved speed profile). [Industrial Applicability]

[0052] To provide a component mounting device and a mounting head inspection method that can easily and quickly inspect a belt provided in the mounting head. [Explanation of symbols]

[0053] 1. Parts mounting device 21 Shaft member 22 nozzles 30 Control Unit 33 Motor 33J motor shaft 34 Rotation transmission mechanism 44 Belt 51 Motor driver 52 Load detection unit 53 Load factor calculation section 54 Judgment section μ Load factor E1 First threshold (reference value) E2 Second threshold (reference value) BH parts KB board

Claims

1. 1. A component mounting device that mounts components on a substrate using a mounting head having a nozzle that picks up components, a shaft member with the nozzle at its lower end, a motor with a motor shaft, and a belt that transmits rotation of the motor shaft to the shaft member, a motor driver that operates the motor under predetermined operating conditions during testing; a load detection unit that detects a load acting on the motor while the motor is operating under the inspection operating conditions; a load factor calculation unit that calculates a load factor of the motor based on the load detected by the load detection unit; a determination unit that determines a state of the belt based on the load factor calculated by the load factor calculation unit; A component mounting device comprising:

2. 2. The component mounting device according to claim 1, wherein the inspection operating conditions are operating conditions under which the motor shaft rotates to a predetermined rotation position at a predetermined speed profile.

3. 2. The component mounting device according to claim 1, wherein the determining unit determines that the belt is in a maintenance-requiring state when the load factor is lower than a predetermined reference value.

4. 2. The component mounting device according to claim 1, wherein the plurality of shaft members are synchronously rotated in the same direction by one of the motors via the belt.

5. 1. A method for inspecting a mounting head in a component mounting device that mounts components on a board using a mounting head having a nozzle that picks up components, a shaft member with the nozzle at its lower end, a motor with a motor shaft, and a belt that transmits rotation of the motor shaft to the shaft member, comprising: a load detection step of operating the motor under predetermined inspection operating conditions and detecting a load acting on the motor during the operation; a load factor calculation step of calculating a load factor of the motor based on the load detected in the load detection step; a determining step of determining a state of the belt based on the calculated load factor; A mounting head inspection method comprising:

6. 6. The mounting head inspection method according to claim 5, wherein the inspection operating conditions are operating conditions under which the motor shaft rotates to a predetermined rotation position with a predetermined speed profile.

7. 6. The mounting head inspection method according to claim 5, wherein the determining step determines that the belt is in a maintenance-requiring state when the load factor is below a predetermined reference value.

8. 8. The mounting head inspection method according to claim 7, wherein the load when the belt is new is used as a base for calculating the reference value.

Images