control device

Abstract

Disclosed is a control device that controls a drive device of a conveyor for transferring a substrate to a predetermined position. The control device comprises: a measurement unit that measures an actual distance between the predetermined position and the substrate; and a correction unit that controls the drive device on the basis of the actual distance measured by the measurement unit, and corrects the position of the substrate so that the substrate is disposed in the predetermined position.

Description

[Technical Field]

[0001] The technology disclosed in this specification relates to a control device that controls a drive device of a conveyor that transports a substrate to a predetermined position. [Background technology]

[0002] Patent Document 1 discloses a component mounting device that has a transport means that transports a board with a board recognition mark on its upper surface in a horizontal direction and a camera that captures an image of the board recognition mark from above. When the component mounting device recognizes that the center of the board recognition mark is positioned at a predetermined reference point within the field of view of the camera, it stops the transport means. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-278014 Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, the number of circuit boards produced per unit time by component mounting devices has increased. Accordingly, the speed at which the conveying means conveys the boards has also increased, and the acceleration (absolute value) when the boards accelerate or decelerate has also increased, as has the vibration transmitted from the conveying means to the boards. Simply recognizing a board recognition mark on the board and stopping the conveying means can cause the board to deviate from its predetermined reference position due to the vibration transmitted from the conveying means to the board. This specification provides a technology for preventing the board from deviating from its predetermined position. [Means for solving the problem]

[0005] The control device disclosed in this specification includes a measurement unit that measures the actual distance between the predetermined position and the substrate, and a correction unit that controls the drive device based on the actual distance measured by the measurement unit and corrects the position of the substrate so that the substrate is positioned at the predetermined position.

[0006] With this configuration, even if the substrate is displaced from its predetermined position, the position of the substrate can be corrected based on the actual distance measured by the measurement sensor, thereby preventing the substrate from being displaced from its predetermined position. [Brief explanation of the drawings]

[0007] [Figure 1] A schematic diagram of a mounting device is shown. [Figure 2] FIG. 1 shows a block diagram of a mounting device. [Figure 3] This shows a view of the conveyor from above when the board has reached the entrance. [Figure 4] 10 shows a top view of the conveyor when the substrate has reached a predetermined position. [Figure 5] FIG. 10 shows a top view of the conveyor in the second embodiment. [Figure 6] 10 shows a flowchart of a slip detection process in the third embodiment. [Figure 7] 13 shows a flowchart of a slip detection process in the fourth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] The main features of the embodiments described below are listed below. Note that the technical elements described below are independent technical elements that exhibit technical utility alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing.

[0009] (Feature 1) The measurement unit may include a sensor that measures the actual distance by using reflected light of a laser irradiated onto the substrate.

[0010] (Feature 2) In addition to the function of measuring the actual distance, the measurement unit may have a function of detecting that the substrate has reached an entrance of the conveyor, and a function of detecting that the substrate has reached an exit of the conveyor.

[0011] According to this configuration, the measurement unit can be made to not only measure the actual distance but also detect whether the substrate has reached the entrance and the exit.

[0012] (Feature 3) The measurement unit may be provided separately from a mounting unit for mounting components onto the board.

[0013] For example, consider a comparative example in which the measurement unit is integrated with the mounting unit. In this comparative example, the mounting unit cannot be operated to prepare for component mounting while the measurement unit is in use. In contrast, with the above configuration, the mounting unit can be operated independently of the measurement unit, and the mounting unit can be prepared for component mounting while the measurement unit is in use.

[0014] (Feature 4) The control device may further include an alarm unit that executes a predetermined alarm operation when an absolute value of a difference between a value indicating the speed of the conveyor and an amount of change per unit time of the actual distance measured by the measurement unit is equal to or greater than a first predetermined value.

[0015] When the absolute value of the difference between the value indicating the conveyor speed and the change in the actual distance measured by the measurement unit per unit time is equal to or greater than a first predetermined value, it means that the conveyor speed and the board speed are different. In this case, the board may move out of alignment with the conveyor, and the board may not be positioned in the predetermined position. With the above configuration, the measurement unit can be used to detect that the board is moving out of alignment with the conveyor. Then, a predetermined notification operation can be performed to notify the user that the board is moving out of alignment with the conveyor.

[0016] (Feature 5) The control device may further include a control unit that controls the drive device such that the absolute value of the difference between a value indicating the speed of the conveyor and a change in the actual distance per unit time measured by the measurement unit is less than a third predetermined value when the absolute value of the difference is equal to or greater than a second predetermined value.

[0017] According to this configuration, when it is detected that the board is moving out of alignment with the conveyor, the drive device can be controlled to automatically eliminate the board's misalignment with the conveyor.

[0018] (First Example) (Mounting device 10; Figures 1 and 2) The mounting apparatus 10 is an apparatus that produces circuit boards by mounting components (e.g., electronic components such as resistors) on a substrate 100. The mounting apparatus 10 includes an entrance sensor 12, an exit sensor 14, a distance sensor 16, a drive device 18, a display unit 20, a control unit 30, a mounting unit 50, and a component feeder 60.

[0019] The driving device 18 is a device that drives the conveyor 18a that transports the substrate 100 into the mounting device 10. The driving device 18 is an actuator such as a motor. The upstream end of the conveyor 18a is connected to a loading device (not shown) that loads the substrate 100 onto the conveyor 18a, and the downstream end of the conveyor 18a is connected to a destination of the manufactured circuit board (for example, a reflow device (not shown)).

[0020] The entrance sensor 12 is installed at the entrance on the upstream side of the conveyor 18a and detects the board 100 reaching the entrance. The exit sensor 14 is installed at the exit on the downstream side of the conveyor 18a and detects the board 100 reaching the exit. The entrance sensor 12 and the exit sensor 14 are, for example, photoelectric sensors equipped with a light-emitting unit and a light-receiving unit. In a modified example, the entrance sensor 12 and the exit sensor 14 may be contact-type limit switches, magnetic switches, etc. The entrance sensor 12 and the exit sensor 14 each output either a value of "0 (e.g., light-transmitting)" indicating that the board 100 has not passed in front of the respective sensor, or a value of "1 (e.g., light-blocking)" indicating that the board 100 has passed in front of the respective sensor.

[0021] Distance sensor 16 is a sensor that measures the actual distance between a predetermined position and board 100 being transported by conveyor 18a. The predetermined position is a fixed position on conveyor 18a for mounting components on board 100. Distance sensor 16 is, for example, a laser sensor that measures distance by utilizing reflected light of a laser irradiated onto board 100. In a modified example, distance sensor 16 may be another non-contact type sensor (for example, an ultrasonic sensor that uses ultrasonic waves).

[0022] The distance sensor 16 is supported on the ceiling inside the mounting apparatus 10 above the conveyor 18a. The distance sensor 16 is movable up and down along the height direction of the mounting apparatus 10. The distance sensor 16 descends to the same height as the substrate 100 and irradiates the laser in a horizontal direction. In a modified example, the distance sensor 16 may descend to a position higher than the substrate 100 and irradiate the laser in an obliquely downward direction.

[0023] The mounting unit 50 mounts the components supplied from the component feeder 60 onto the board 100 fixed at a fixed position on the conveyor 18a. A nozzle 50a that picks up the components in the component feeder 60 is attached to the tip of the mounting unit 50.

[0024] 1 is a cross-section of the mounting apparatus 10 as seen from the conveying direction of the conveyor 18a. The mounting unit 50 is movable horizontally (i.e., left-right and vertical directions on the paper). The mounting unit 50 moves above the component feeder 60 and picks up components in the component feeder 60 with the nozzle 50a. The mounting unit 50 moves above the board 100, which is fixed at a fixed position on the conveyor 18a, and mounts the components picked up by the nozzle 50a onto the board 100. By repeating this operation, a circuit board is produced.

[0025] The display unit 20 is a display for displaying various information. The control unit 30 controls the units 12 to 20, 50, 60, etc. of the mounting device 10. The control unit 30 includes a CPU 32 and a memory 34. The CPU 32 executes various processes in accordance with a program 40 stored in the memory 34. The memory 34 is configured by a volatile memory, a non-volatile memory, etc.

[0026] In a conventional control method for placing the substrate 100 at a predetermined position, the control unit 30 monitors the rotation speed of the drive device 18 from the timing when the entrance sensor 12 detects the arrival of the substrate 100. Then, the control unit 30 stops the drive device 18 when the rotation speed of the drive device 18 reaches a predetermined rotation speed. In this way, the substrate 100 is placed at the predetermined position. Here, the predetermined rotation speed is set in advance based on, for example, the distance between the predetermined position and the entrance sensor 12, the specifications of the drive device 18, etc.

[0027] However, in recent years, as the number of circuit boards produced per unit time has increased, the conveying speed of the conveyor 18a has also increased, increasing the acceleration (absolute value) of the board 100 when it accelerates or decelerates, and also increasing the vibration transmitted from the conveyor 18a to the board 100. The increased acceleration (absolute value) and vibration increase the risk of the board 100 shifting from its predetermined position. Furthermore, the frictional force (the force that prevents the board 100 from shifting) generated between the board 100 and the conveyor 18a decreases over time due to wear on the surface of the conveyor 18a, increasing the risk of the board 100 shifting from its predetermined position. In this embodiment, in order to prevent the board 100 from shifting from its predetermined position, a correction process is performed to correct the position of the board 100 using the distance sensor 16.

[0028] (Correction process: Figures 3 and 4) In this embodiment, when the entrance sensor 12 detects that the substrate 100 has reached the entrance, the control unit 30 lowers the distance sensor 16 so that it approaches the conveyor 18a (FIG. 3). In this embodiment, the control unit 30 also stops the drive unit 18 using a predetermined number of rotations, as in the conventional control method. After the drive unit 18 has stopped, the control unit 30 determines whether the actual distance indicated by the output value of the distance sensor 16 is equal to or greater than the predetermined distance. If the control unit 30 determines that the actual distance is less than the predetermined distance, it does not perform the correction process.

[0029] On the other hand, if the control unit 30 determines that the actual distance is equal to or greater than the predetermined distance (FIG. 4), it executes a correction process. In the correction process, the control unit 30 drives the drive unit 18 again to correct the position of the substrate 100 so that the substrate 100 is positioned at the predetermined position. If the substrate 100 has not reached the predetermined position (FIG. 4), the control unit 30 rotates the drive unit 18 in the forward direction to correct the position. If the substrate 100 has exceeded the predetermined position, the control unit 30 rotates the drive unit 18 in the reverse direction to correct the position. The control unit 30 repeats the above correction until the distance sensor 16 outputs an output value indicating a distance less than the predetermined distance. This allows the position of the substrate 100 to be corrected based on the actual distance measured by the distance sensor 16, even if the substrate 100 deviates from the predetermined position. This prevents the substrate 100 from deviating from the predetermined position.

[0030] Furthermore, when correcting the position of the substrate 100, the conveying speed of the substrate 100 is made slower than the conveying speed when moving the substrate 100 from the entrance to a predetermined position. This prevents slippage between the substrate 100 and the conveyor 18a. Although the conveying speed of the substrate 100 is slower when correcting the position, the moving distance for correcting the position is short, so correcting the position does not require a long time. In this embodiment, the positioning accuracy of the substrate 100 can be improved while preventing a decrease in productivity.

[0031] The process for correcting the position of the substrate 100 is not limited to the above process, and may be, for example, feedback control using the output value of the distance sensor 16, rather than using a predetermined number of rotations as in conventional control methods.

[0032] Also, for example, a comparative example can be considered in which the distance sensor 16 is integrated with the mounting unit 50. In this comparative example, the mounting unit 50 cannot be operated while the distance sensor 16 is being used to prepare for mounting a component on the board 100 (for example, by picking up a component with the nozzle 50a). In contrast, according to the configuration of this embodiment, the mounting unit 50 can be operated independently of the distance sensor 16 while the distance sensor 16 is being used to prepare the mounting unit 50 for mounting a component on the board 100. Note that the configuration of the above comparative example may be adopted in a modified example.

[0033] (Correspondence) The conveyor 18a and the driving device 18 are examples of a "conveyor" and a "driving device", respectively. The distance sensor 16 is an example of a "measuring unit". The control unit 30 that executes the correction process is an example of a "correction unit". A system including the distance sensor 16 and the control unit 30 is an example of a "control device". In a modified example, the correction process may be executed by another device (e.g., a server) that is provided separately from the mounting device 10. In this modified example, the other device is an example of a "correction unit".

[0034] (Second Example) (Correction process; Figure 5) This embodiment is similar to the first embodiment except that the mounting apparatus 10 does not include the entrance sensors 12 and 14, but includes a distance sensor 216. In addition to the same function as in the first embodiment of measuring the actual distance between a predetermined position and the substrate 100, the distance sensor 216 also includes a function of detecting that the substrate 100 has reached the entrance of the conveyor 18a and a function of detecting that the substrate 100 has reached the exit of the conveyor 18a.

[0035] As shown in FIG. 5, the distance sensor 216 is disposed at a position that does not overlap with the conveyor 18a when viewed from above the conveyor 18a. The distance sensor 216 is capable of irradiating a laser beam over a wide range from the entrance to the exit. The distance sensor 216 detects the arrival of the substrate 100 at the entrance by utilizing the reflected light of the laser beam irradiated toward the entrance. The distance sensor 216 also measures the actual distance between a predetermined position and the substrate 100 by utilizing the reflected light of the laser beam irradiated between the entrance and the exit. The distance sensor 216 also detects the arrival of the substrate 100 at the exit by utilizing the reflected light of the laser beam irradiated toward the exit.

[0036] According to the configuration of this embodiment, the distance sensor 16 can serve as both the entrance sensor 12 and the exit sensor 14. Furthermore, compared to the first embodiment in which the entrance sensor 12 and the exit sensor 14 are provided separately from the distance sensor 16, the configuration of the mounting device 10 can be simplified.

[0037] (Third Example) This embodiment is similar to the first embodiment except that in addition to the above correction processing, a slip detection processing, which will be described later, is executed.

[0038] (Slip detection process; Figure 6) The slippage detection process is triggered by the entrance sensor 12 detecting that the substrate 100 has reached the entrance. In S10, the control unit 30 calculates the speed of the substrate 100 (hereinafter referred to as "substrate speed") from the amount of change per unit of the actual distance indicated by the output value of the distance sensor 16.

[0039] In S12, the control unit 30 determines whether the absolute value of the difference between the drive speed and the substrate speed is less than a predetermined value. Here, the drive speed is the speed of the conveyor 18a, and is calculated, for example, from the rotation speed of the drive device 18. If the control unit 30 determines that the absolute value of the difference between the drive speed and the substrate speed is less than the predetermined value (YES in S12), it skips the process of S14, which will be described later, and returns to S10.

[0040] On the other hand, if the control unit 30 determines that the absolute value of the difference between the drive speed and the substrate speed is equal to or greater than a predetermined value (NO in S12), the control unit 30 proceeds to S14. If the absolute value of the difference between the drive speed and the substrate speed is equal to or greater than a predetermined value, there is a possibility that the substrate 100 is moving out of alignment with respect to the conveyor 18a due to vibration of the conveyor 18a or the like. In this case, there is a possibility that the substrate 100 will not be positioned at a predetermined position. In S14, the control unit 30 causes the display unit 20 to display a notification screen indicating that the substrate 100 is moving out of alignment with respect to the conveyor 18a. When S14 ends, the control unit 30 returns to the processing of S10.

[0041] According to the configuration of this embodiment, the notification screen of S14 can notify the user that the substrate 100 is moving misaligned relative to the conveyor 18a. The user can perform work to eliminate the misalignment of the substrate 100 (for example, maintenance work such as replacing the conveyor 18a). The predetermined value of S12 is an example of a "first predetermined value." Displaying the notification screen of S14 is an example of a "predetermined notification action." Note that the "predetermined notification action" is not limited to displaying the notification screen, and may be, for example, outputting a warning sound, turning on a warning light, etc.

[0042] (Fourth Example) (Slip detection process; Figure 7) This embodiment is similar to the third embodiment except for a part of the slippage detection process, which is the same as the slippage detection process of the third embodiment (see FIG. 6) except that the process of S24 is executed instead of S14.

[0043] If the control unit 30 determines that the absolute value of the difference between the drive speed and the substrate speed is equal to or greater than a predetermined value (NO in S12), the control unit 30 proceeds to S24. In S24, the control unit 30 executes slippage elimination control. The slippage elimination control is a process of controlling the drive unit 18 so that the absolute value of the difference between the drive speed and the substrate speed is less than a predetermined value. In the slippage elimination control, for example, the rotational speed of the drive unit 18 is adjusted. With this configuration, when it is detected that the substrate 100 is moving with a deviation relative to the conveyor 18a, the deviation of the substrate 100 with respect to the conveyor 18a can be automatically eliminated. The predetermined value in S12 is an example of a "second predetermined value" and a "third predetermined value," and the control unit 30 executing S24 is an example of a "control unit." In a modified example, the "third predetermined value" may be a value different from the "second predetermined value," for example, a value smaller than the "second predetermined value."

[0044] A note about the control device described in the embodiment will be given below. The "predetermined position" is not limited to a fixed position for mounting a component on the substrate 100, but may also be, for example, a fixed position for printing solder on the substrate 100.

[0045] The technical elements described in this specification or drawings exhibit technical utility either alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. Furthermore, the technologies illustrated in this specification or drawings simultaneously achieve multiple objectives, and achieving one of those objectives is itself technically useful. [Explanation of symbols]

[0046] 10: Mounting equipment 12: Inlet sensor 14: Exit sensor 16: Distance sensor 18: Drive unit 18a: Conveyor 20: Display section 30: Control section 32 :CPU 34: Memory 40: Program 50: Mounting unit 50a: Nozzle 60: Parts feeder 100: Substrate 216: Distance sensor

Claims

1. A control device that controls a drive device of a conveyor that transports a substrate to a predetermined position, a measuring unit that measures an actual distance between the predetermined position and the substrate; a correction unit that controls the drive device based on the actual distance measured by the measurement unit and corrects the position of the substrate so that the substrate is placed at the predetermined position; a notification unit that executes a predetermined notification operation when an absolute value of a difference between a value indicating the speed of the conveyor and an amount of change per unit time of the actual distance measured by the measurement unit is equal to or greater than a first predetermined value; A control device comprising:

2. The control device further 2. The control device according to claim 1, further comprising a control unit that controls the drive device so that the absolute value of the difference between the value indicating the speed of the conveyor and the change in the actual distance per unit time measured by the measurement unit is less than a third predetermined value when the absolute value of the difference is equal to or greater than a second predetermined value.

3. A control device that controls a drive device of a conveyor that transports a substrate to a predetermined position, a measuring unit that measures an actual distance between the predetermined position and the substrate; a correction unit that controls the drive device based on the actual distance measured by the measurement unit and corrects the position of the substrate so that the substrate is placed at the predetermined position; a control unit that, when an absolute value of a difference between a value indicating the speed of the conveyor and a change amount per unit time of the actual distance measured by the measurement unit is equal to or greater than a second predetermined value, controls the drive device so that the absolute value of the difference becomes less than a third predetermined value; A control device comprising:

4. The control device according to claim 1 , wherein the measurement unit includes a sensor that measures the actual distance by utilizing reflected light of a laser irradiated onto the substrate.

5. 5. The control device according to claim 1, wherein the measurement unit has, in addition to the function of measuring the actual distance, a function of detecting that the substrate has reached an entrance of the conveyor and a function of detecting that the substrate has reached an exit of the conveyor.

6. The control device according to claim 1 , wherein the measurement unit is provided separately from a mounting unit that mounts components on the board.

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