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: The motor is servo-controlled to rotate the motor shaft from a reference position to a predetermined rotation position (ST1 to ST3. The rotational position (Φ 1) of the motor shaft detected by the encoder is read (ST4. First rotational position reading step). Then, the servo control of the motor is released (ST5. In a state where the motor shaft is returned by a minute angle by the belt, the rotational position (Φ 2) of the motor shaft detected by the encoder is read (ST6. Second rotational position reading step). An angular difference between the read rotational position (Φ 1) and rotational position (Φ 2) of the motor shaft is calculated as a return angle Δ Φ of the motor shaft (ST7. Based on the calculated return angle Δ Φ, the state of the belt is determined (ST8 to ST10. 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 an encoder that detects the rotational position of the motor shaft, a motor driver that servo-controls the motor to rotate the motor shaft from a reference position to a predetermined rotational position and then releases servo control of the motor, and a determination unit that determines the state of the belt based on the rotational position of the motor shaft detected by the encoder when the motor shaft has been rotated to the predetermined rotational position by the motor driver and the rotational position of the motor shaft detected by the encoder when servo control of the motor is released.

[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 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 includes: a motor shaft rotation step of servo-controlling the motor to rotate the motor shaft from a reference position to a predetermined rotational position; a first rotational position reading step of reading the rotational position of the motor shaft detected when the motor shaft has rotated to the predetermined rotational position; a servo-off step of releasing the servo control of the motor after the first rotational position reading step; a second rotational position reading step of reading the rotational position of the motor shaft detected when the servo control of the motor is released; and a determination step of determining the condition of the belt based on the rotational position of the motor shaft read in the first rotational position reading step and the rotational position of the motor shaft read in the second rotational position reading step. [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 a first embodiment of the present disclosure. [Figure 2] 1 is a partial perspective view of a mounting head included in a component mounting device according to a first 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 first embodiment of the present disclosure. [Figure 4] 1 is a cross-sectional perspective view of a portion of a mounting head included in a component mounting device according to a first embodiment of the present disclosure. [Figure 5] 2 is a simplified plan view showing the arrangement of a motor and a rotation transmission mechanism provided in a mounting head of the component mounting device according to the first embodiment of the present disclosure. FIG. [Figure 6] 2 is a schematic side view of a motor and a rotation transmission mechanism provided in the mounting head of the component mounting device according to the first embodiment of the present disclosure. FIG. [Figure 7] 4 is a graph showing the relationship between the return angle of the motor shaft included in the component mounting device according to the first embodiment of the present disclosure and the elongation of the belt and the usage time of the belt. [Figure 8] 5A, 5B, and 5C are diagrams illustrating the relationship between the rotation of a motor and the rotation of a shaft member included in the component mounting device according to the first embodiment of the present disclosure. [Figure 9] 4 is a flowchart showing the flow of an inspection performed by the component mounting device according to the first embodiment of the present disclosure. [Figure 10] 10 is a flowchart showing the flow of an inspection performed by a component mounting device according to a second embodiment of the present disclosure. [Figure 11] 10 is a graph showing the relationship between the return angle of a motor shaft included in a component mounting device according to a second embodiment of the present disclosure, and the elongation of a belt and the usage time of the belt. DETAILED DESCRIPTION OF THE INVENTION

[0010] (Embodiment 1) 1 shows a component mounting device 1 according to a first 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 operator OP) is defined as the X direction, the horizontal direction perpendicular to the X direction (the front-back direction as seen from the operator OP) is defined as the Y direction, and the up-down direction is defined 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 the first 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 within the base portion 31. The motor 33 has a motor shaft 33J, which is its rotation drive shaft, facing downward. The motor 33 is provided with an encoder 40 that detects the rotation position of the motor shaft 33J (FIGS. 3 and 4).

[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] 3 and 6, the control unit 30 includes the aforementioned motor driver 51, as well as a return angle calculation unit 52 and a determination unit 53. When inspecting the mounting head 14, the motor driver 51 sets the motor 33 to a "servo on" state, which servo controls the motor 33, and then rotates the motor shaft 33J from the reference position NP to a predetermined rotation position (FIG. 8(a) → FIG. 8(b)), and then sets the motor 33 to a "servo off" state, which releases the servo control of the motor 33. Here, "releasing the servo control" means that the motor shaft 33J is placed in a state in which it can rotate freely (free rotation state).

[0034] When motor shaft 33J rotates from reference position NP to a predetermined rotation position, the rotation is transmitted to shaft member 21 via tension P of belt 44, and shaft member 21 rotates accordingly to rotation position Θ that corresponds to the rotation position of motor shaft 33J. At this time, motor shaft 33J receives a load from shaft member 21 via belt 44. When servo control of motor 33 is subsequently released, motor shaft 33J enters a free rotation state, while shaft member 21 remains at approximately the position where it rotated accordingly, so motor shaft 33J is returned a small angle toward reference position NP by tension P of belt 44 (Figure 8(b) → Figure 8(c)).

[0035] The return angle calculation unit 52 reads the rotational position (Φ1) of the motor shaft 33J detected by the encoder 40 when the motor driver 51 has rotated the motor shaft 33J to the above-mentioned predetermined rotational position, and also reads the rotational position (Φ2) of the motor shaft 33J detected by the encoder 40 when servo control of the motor 33 is released (when the motor shaft 33J has returned by a small angle toward the reference position NP).The return angle calculation unit 52 then calculates the angular difference between these two read rotational positions (Φ1, Φ2) as the return angle ΔΦ (=Φ1-Φ2) of the motor shaft 33J.

[0036] Determination unit 53 determines the state of belt 44 based on return angle ΔΦ (=Φ1-Φ2) calculated by return angle calculation unit 52. In the first embodiment, determination unit 53 compares the calculated return angle ΔΦ with a predetermined threshold value (threshold value E1 shown in FIG. 7), and determines that belt 44 is in a state requiring maintenance (maintenance required state) when return angle ΔΦ is below threshold value E1.

[0037] 9 shows an example of a specific flow of inspection of the mount head 14 (a method of inspecting the mount head 14) in the first embodiment. The inspection is preferably performed without a component BH being adsorbed onto the nozzle 22, but if the component BH is relatively small and lightweight, the inspection may be performed with the component BH adsorbed onto the nozzle 22. This is because if the component BH is small and lightweight, the return angle of the motor shaft 33J is less affected by the inertial force of the component BH that occurs when the servo of the motor 33, described below, is turned off.

[0038] In the inspection, first, the control unit 30 turns on the servo of the motor 33 via the motor driver 51 (step ST1), and then positions the motor shaft 33J at a reference position NP (for example, an origin position where the rotation angle is 0°) (step ST2, FIG. 8(a)). Then, the control unit 30 rotates the motor shaft 33J to a predetermined rotation position (for example, a position where the rotation angle of the motor shaft 33J is +90°) (step ST3, FIG. 8(b)).

[0039] After rotating the motor shaft 33J from the reference position NP to a predetermined rotational position as described above, the motor driver 51 holds the motor shaft 33J at that position for a predetermined time (e.g., 100 ms) to stabilize the motor shaft 33J so that it does not vibrate in the rotational direction. Here, the "predetermined time" is determined by conducting an experiment (or performing a simulation analysis) under similar conditions to obtain data (time). Then, when the predetermined time has elapsed since the motor shaft 33J was positioned at the predetermined rotational position and the motor shaft 33J has stabilized, the return angle calculation unit 52 reads the rotational position (Φ1) of the motor shaft 33J detected by the encoder 40 (step ST4). Alternatively, after the motor driver 51 rotates the motor shaft 33J from the reference position NP to a predetermined rotational position, the return angle calculation unit 52 reads the rotational position of the motor shaft 33J detected by the encoder 40 and determines that the motor shaft 33J has stabilized when the fluctuations in the read rotational position converge. The rotational position (Φ1) is then read at that time.

[0040] In step ST4, the return angle calculation unit 52 reads the rotational position (Φ1) of the motor shaft 33J detected by the encoder 40. Then, the motor driver 51 turns off (releases) the servo control of the motor 33 (step ST5). After the servo control is turned off and the motor shaft 33J, which is now in a free-rotating state, is returned by a small angle due to the tension P of the belt 44 (FIG. 8(b) → FIG. 8(c)), the motor shaft 33J is held in that position for a predetermined time until the motor shaft 33J is stabilized. The "predetermined time" in this case is also previously obtained by conducting an experiment (or by performing a simulation analysis) under similar conditions. Note that the time required for the motor shaft 33J to stabilize when the servo is on is generally different from the time required for the motor shaft 33J to stabilize when the servo is off.

[0041] Once the motor shaft 33J has reached a stable state, the return angle calculation unit 52 reads the rotational position (Φ2) of the motor shaft 33J detected by the encoder 40 (step ST6). After reading the rotational position (Φ1) of the motor shaft 33J detected by the encoder 40 in step ST6, the return angle calculation unit 52 calculates the angle difference (=Φ1-Φ2) between the rotational position (Φ1) and the rotational position (Φ2) as the return angle ΔΦ of the motor shaft 33J (step ST7).

[0042] After the return angle calculation unit 52 calculates the return angle ΔΦ (=Φ1-Φ2) in step ST7, the determination unit 53 compares the calculated return angle ΔΦ with a threshold value E1 to determine whether the return angle ΔΦ is below the threshold value E1 (step ST8). If the return angle ΔΦ is not below the threshold value E1 (ΔΦ≧E1), the determination unit 53 determines that the belt 44 is in a state where maintenance is not required (good state) (step ST9).

[0043] On the other hand, in step ST8, when the return angle ΔΦ calculated in step ST7 is less than the threshold value E1 (ΔΦ < E1), the determination unit 53 determines that the belt 44 is in a maintenance-required state (step ST10). After proceeding to step ST9 or step ST10, the determination unit 53 causes the touch panel 16 to display the content determined in each step (step ST11). Therefore, the operator OP can easily and quickly grasp the state of the belt 44. Thus, the operator OP does not need to perform maintenance on the belt 44 until the belt 44 reaches the maintenance-required state, and only needs to perform maintenance on the belt 44 once it reaches the maintenance-required state.

[0044] As described above, in the component mounting apparatus 1 according to the first embodiment, the motor driver 51 servo-controls the motor 33 to rotate the motor shaft 33J from the reference position NP to a predetermined rotational position, and then releases the servo-control of the motor 33. The return angle calculation unit 52 calculates the return angle ΔΦ (= Φ2 - Φ1) of the motor shaft 33J from the angle difference between the rotational position (Φ1) of the motor shaft 33J detected by the encoder 40 in the state of rotating to the predetermined rotational position and the rotational position (Φ2) of the motor shaft 33J detected by the encoder 40 in the state of slightly returning to the reference position NP side after the servo-control of the motor 33 is released. Then, based on the calculated return angle ΔΦ, the determination unit 53 determines the state of the belt 44 (compares the calculated return angle ΔΦ with a predetermined threshold value E1, and determines that the belt 44 is in a maintenance-required state when the return angle ΔΦ is less than the threshold value E1).

[0045] In addition, in the case of the configuration in which a plurality of shaft members 21 are synchronously rotationally driven in the same direction through the belt 44 by one motor 33 as in the first embodiment, since the total weight of the plurality of shaft members 21 is much larger than the weight of the motor shaft 33J, when the servo-control of the motor 33 is released, only the motor shaft 33J is returned, and it is easy to obtain an accurate determination result.

[0046] To explain the inspection procedure (inspection method) of the mounting head 14 in the first embodiment, the control unit 30 first servo-controls the motor 33 to rotate the motor shaft 33J from the reference position NP to a predetermined rotational position Φ1 (steps ST1 to ST3, motor shaft rotation step), and reads the rotational position (Φ1) of the motor shaft 33J detected by the encoder 40 in this state (step ST4, first rotational position reading step).Then, the control unit 30 releases the servo control of the motor 33 (step ST5, servo-off step), and when the motor shaft 33J returns a small angle toward the reference position NP, reads the rotational position (Φ2) of the motor shaft 33J detected by the encoder 40 in this state (step ST6, second rotational position reading step).

[0047] After reading the rotational position (Φ2) of the motor shaft 33J detected by the encoder 40, the control unit 30 calculates the return angle ΔΦ (=Φ1-Φ2) of the motor shaft 33J as the angular difference between the rotational position (Φ1) of the motor shaft 33J read in step ST4 (first rotational position reading step) and the rotational position (Φ2) of the motor shaft 33J read in step ST6 (second rotational position reading step) (step ST7, return angle calculation step).Then, based on the calculated return angle ΔΦ, the control unit 30 determines the state of the belt 44 (compares the calculated return angle ΔΦ with a predetermined threshold E1, and determines that the belt 44 is in a maintenance-requiring state if the return angle ΔΦ is below the threshold E1) (steps ST8 to ST10, determination step).

[0048] As described above, the component mounting apparatus 1 (method of inspecting the mounting head 14) according to the first embodiment can easily inspect whether the belt 44 is in a state requiring maintenance, 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 of inspecting the mounting head 14) according to the first embodiment can easily and quickly inspect the belt 44 provided in the mounting head 14. Furthermore, this allows the belt 44 to be inspected in a short time, within a time period unrelated to the production of the board KB itself, such as when the component mounting operation on a certain board KB is completed and the board KB begins to be unloaded, before the next board KB is loaded, or when the model of the board KB is changed.

[0049] In the first embodiment, the threshold value E1 described above may be a fixed value determined at the time of product shipment of the component mounting device 1, or may be a changeable variable value. For example, a plurality of threshold values ​​E1 may be prepared, and one may be selected and used depending on the usage environment of the belt 44, etc. Alternatively, a plurality of threshold values ​​that change in stages may be prepared, and the warning level may change in stages each time each threshold is exceeded (for example, a low warning recommending that the belt 44 be changed → a medium warning indicating that the time to change the belt 44 is approaching → a high warning indicating that the belt 44 must be changed).

[0050] (Embodiment 2) Next, a second embodiment of the present disclosure will be described. The configuration of the component mounting device 1 in the second embodiment is the same as that of the component mounting device 1 in the first embodiment, but the inspection procedure is different. Because there are individual differences among belts 44, the initial value of the return angle of the motor shaft 33J differs depending on the belt 44. Therefore, the threshold value E1 described above should originally differ depending on the belt 44, but in the first embodiment, the threshold value E1 was treated as a common value for all belts 44 without taking into account the individual differences among the belts 44. In the second embodiment, the individual differences among the belts 44 are taken into account, and the threshold value E1 is determined based on the amount of change from the initial value of the return angle of the motor shaft 33J.

[0051] 10 shows an example of a specific flow of inspection of the mounting head 14 (a method of inspecting the mounting head 14) in the second embodiment. The flowchart in the second embodiment is the same as the flowchart in the first embodiment from the motor shaft rotation step to the return angle calculation step (steps ST1 to ST7) (only the determination step is different), so the same steps are assigned the same step symbols and descriptions thereof will be omitted.

[0052] In the second embodiment, after the return angle calculation unit 52 calculates the return angle ΔΦ (=Φ1-Φ2) in step ST7, the determination unit 53 reads out an initial return angle ΔΦ0 as an initial value stored in a storage unit (not shown) (step ST18). This initial return angle ΔΦ0 is the return angle ΔΦ first calculated after the most recent maintenance of the belt 44, and is approximately the maximum value that the return angle ΔΦ can take (FIG. 11).

[0053] After reading the initial return angle ΔΦ0 in step ST18, the determination unit 53 calculates a return angle difference value DS (=ΔΦ0 - ΔΦ), which is the difference between the return angle ΔΦ calculated in step ST7 and the initial return angle ΔΦ0 read in step ST18 (step ST19). This return angle difference value DS gradually increases as the usage time of the belt 44 increases, i.e., as the return angle ΔΦ decreases. When the return angle difference value DS reaches a reference difference value E2 shown in FIG. 11, the belt 44 enters a maintenance-required state. Here, the reference difference value E2 is the difference between the initial return angle ΔΦ0 and a threshold value for the maintenance-required state (threshold value E1 in the first embodiment), and is determined in advance through evaluation experiments during development. Alternatively, the reference difference value E2 is calculated by multiplying the initial return angle ΔΦ0 by a predetermined coefficient (determined in advance through evaluation experiments during development, for example, 0.6). In this case, since the initial return angle ΔΦ0 varies depending on the individual belt 44, the reference difference value E2 also varies depending on the belt 44.

[0054] After calculating the return angle difference value DS in step ST19, the determination unit 53 checks whether the return angle difference value DS exceeds the above-mentioned reference difference value E2 (step ST20). If the return angle difference value DS does not exceed the reference difference value E2 (DS≦E2), the determination unit 53 determines that the belt 44 is in a state where maintenance is not required (good state) (step ST21). On the other hand, if the return angle difference value DS exceeds the reference difference value E2 (DS>E2), the determination unit 53 determines that the belt 44 is in a state where maintenance is required (step ST22). After proceeding to step ST21 or step ST22, the determination unit 53 displays the results of the determination made in each step on the touch panel 16 (step ST23).

[0055] Thus, in the second embodiment, the determination process consisting of steps ST18 to ST22 determines that the belt 44 is in a maintenance-requiring state when the return angle difference value DS, which is the difference between the return angle ΔΦ calculated in the return angle calculation process of step ST7 and a preset initial return angle ΔΦ0, exceeds a predetermined reference difference value E2. Similarly to the first embodiment, the component mounting device 1 (method of inspecting the mounting head 14) in the second embodiment also makes it possible to easily inspect 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 improved workability. Therefore, the component mounting device 1 (method of inspecting the mounting head 14) in the second embodiment allows the belt 44 included in the mounting head 14 to be inspected simply and quickly.

[0056] As described above, according to the component mounting device 1 (method of inspecting the mounting head 14) in embodiments 1 and 2, the belt 44 provided on the mounting head 14 can be inspected easily and quickly without requiring a dedicated device as in the conventional case.

[0057] Although the first and second embodiments have been described above, the present disclosure is not limited to the above and various modifications are possible. For example, in the first and second embodiments described above, 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.

[0058] In the first and second embodiments described above, the predetermined rotation position when the motor shaft 33J is rotated from the reference position NP after the motor 33 is put into a servo-controllable state (servo on) is set to a position where the rotation angle of the motor shaft 33J is +90°, but the predetermined rotation position when the motor shaft 33J is rotated from the reference position NP may be another position (such as a position where the rotation angle of the motor shaft 33J is -90°, +180°, -180°, +270°, or -270°). Furthermore, a plurality of or all of these rotation positions may be selected from these rotation positions and inspected sequentially. When the rotational position is +180° (-180°) or +270° (-270°), the reference position NP may always be 0°, but when the rotational position is +180°, the reference position NP may be 90° (when the rotational position is -180°, the reference position NP may be -90°), and when the rotational position is +270, the reference position NP may be +180° (when the rotational position is -270°, the reference position NP may be -180°). [Industrial Applicability]

[0059] 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]

[0060] 1. Parts mounting device 21 Shaft member 22 nozzles 30 Control Unit 33 Motor 33J motor shaft 34 Rotation transmission mechanism 40 Encoder 44 Belt 51 Motor driver 52 Return angle calculation section 53 Judgment section ΔΦ Return angle ΔΦz Previous return angle DS Return angle difference value E1 threshold E2 Reference difference value NP reference position 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, an encoder for detecting the rotational position of the motor shaft; a motor driver that servo-controls the motor to rotate the motor shaft from a reference position to a predetermined rotation position, and then releases the servo control of the motor; a determination unit that determines the state of the belt based on the rotational position of the motor shaft detected by the encoder when the motor shaft is rotated to the predetermined rotational position by the motor driver and the rotational position of the motor shaft detected by the encoder when servo control of the motor is released; A component mounting device comprising:

2. 2. The component mounting device according to claim 1, further comprising a return angle calculation unit that calculates, as a return angle of the motor shaft, an angular difference between the rotational position of the motor shaft detected by the encoder when the motor shaft has been rotated to the predetermined rotational position by the motor driver and the rotational position of the motor shaft detected by the encoder when servo control of the motor is released, and the determination unit determines the state of the belt based on the return angle calculated by the return angle calculation unit.

3. 3. The component mounting device according to claim 2, wherein the determining unit compares the return angle with a predetermined threshold value, and determines that the belt is in a maintenance-requiring state when the return angle is below the threshold value.

4. 3. The component mounting device according to claim 2, wherein the determination unit calculates a difference value between the return angle calculated by the return angle calculation unit and an initial return angle, which is the return angle calculated after the most recent maintenance of the belt, and determines that the belt is in a state requiring maintenance if the calculated difference value exceeds a predetermined reference difference value.

5. 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.

6. 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 motor shaft rotating step of rotating the motor shaft from a reference position to a predetermined rotation position by servo-controlling the motor; a first rotational position reading step of reading a rotational position of the motor shaft detected in a state where the motor shaft has rotated to the predetermined rotational position; a servo-off step of canceling servo control of the motor after the first rotation position reading step; a second rotational position reading step of reading a rotational position of the motor shaft detected in a state where servo control of the motor is released; a determining step of determining a state of the belt based on the rotational position of the motor shaft read in the first rotational position reading step and the rotational position of the motor shaft read in the second rotational position reading step; A mounting head inspection method comprising:

7. 7. The mounting head inspection method of claim 6, further comprising a return angle calculation step of calculating, after the second rotational position reading step, the angular difference between the rotational position of the motor shaft read in the first rotational position reading step and the rotational position of the motor shaft read in the second rotational position reading step as the return angle of the motor shaft, and the determination step determines the state of the belt based on the return angle calculated in the return angle calculation step.

8. 8. The mounting head inspection method of claim 7, wherein the determination step compares the return angle calculated in the return angle calculation step with a predetermined threshold value, and determines that the belt is in a state requiring maintenance if the return angle is below the threshold value.

9. 8. The mounting head inspection method of claim 7, wherein the determination process calculates a difference between the return angle calculated in the return angle calculation process and an initial return angle, which is the return angle calculated after the most recent maintenance of the belt, and determines that the belt is in a state requiring maintenance if the calculated difference value exceeds a predetermined reference difference value.

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