JP2017165548A - Conveying apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technology capable of detecting abnormality of a belt without providing a sensor for detecting a position of a conveyance object.SOLUTION: A control device executes: a first driving process of moving a belt by driving a motor for a first time period which is longer than a time required for a conveyance object to move to an advance end or a retreat end; a belt abnormality detection process of determining that the conveyed object is stopped at the advance end or the retreat end by contact of the conveyance object with a stopper when the driving of the motor is stopped, and determining that abnormality has occurred in the belt when the driving of the motor is not stopped, during the first driving process; and a second driving process of, when it is determined that the conveyance object is located at the advance end or the retreat end in the belt abnormality detection process, driving the motor so as to move the belt in a direction opposite to an operation direction of the first driving process for a second time period required to move the conveyance object to a target position with the position as an origin position.SELECTED DRAWING: Figure 3

Description

  The present specification relates to an apparatus for transporting an object to be transported by driving a belt. In particular, the present invention relates to a technique for detecting an abnormality of a belt used for transporting a transported object.

  In this type of device, a motor is used to drive the belt. By driving the belt with a motor, the object to be transported placed on the upper surface of the belt is transported. In order to control the position of the conveyed object conveyed by the belt, it is necessary to control the driving of the motor. Patent Document 1 discloses an apparatus that controls driving of a belt by a stepping motor. In this apparatus, whether or not the carrier is located at the home position (referred to as a forward end or a backward end in this specification) depends on whether or not the detection body attached to the carrier contacts the detection body (sensor). Detect. When the detection object comes into contact with the detection object, the counter is cleared to zero. The position of the carrier, which is a transported object placed on the belt, is detected by counting the output of the encoder with a counter. In this apparatus, when the detected object (sensor) cannot detect the detected object when the carrier is moved toward the home position, it is possible to detect that an abnormality such as breakage has occurred in the belt.

Japanese Patent Application Laid-Open No. 6-296397

  As described above, in the apparatus described in Patent Literature 1, although abnormality of the belt can be detected, it is detected by the sensor whether or not the object to be conveyed is positioned at the home position. However, when such a sensor is used, an operation for arranging the sensor in the vicinity of the home position is required, and an operation for drawing a wiring for connecting the sensor and the control device or the like is also required. In the present specification, a technique is disclosed in which a belt abnormality can be detected without providing a sensor for detecting whether or not the object to be conveyed is located at a predetermined position.

  The conveyance device disclosed in the present specification can detect an abnormality of a belt that conveys an object to be conveyed placed on the upper surface. The conveyor device is arranged at each of the belt driving motor, the forward end and the backward end of the belt, controls the movement of the object to be transported, and controls the driving of the motor. And a control device that detects whether or not the object to be conveyed is positioned at the forward end or the backward end. The control device executes a first drive process, a belt abnormality detection process, and a second drive process when moving the conveyed object to a target position set between the forward end and the reverse end. In the first driving process, the control device drives the motor for a first time longer than the time required for the conveyed object to move to the forward end or the backward end, thereby moving the belt in the forward end direction or the backward end. Move in the direction. In the belt abnormality detection process, the control device determines that the object to be conveyed is stopped at the forward end or the backward end when the motor is stopped during the first drive process because the conveyed object contacts the stopper. On the other hand, when the driving of the motor does not stop during the first driving process, it is determined that an abnormality has occurred in the belt. In the second drive process, when the control device determines that the conveyed object is positioned at the forward end or the backward end in the belt abnormality detection process, the controller moves the conveyed object to the target position using the position as the origin position. During the second time required for this, the motor is driven so as to move the belt in the direction opposite to the operation direction of the first driving process.

  In the transport apparatus described above, when the transported object is moved to the target position, first, the transported object is a longer time than when the transported object moves from the current position to the end of the moving range (forward end or backward end). A time of 1 is set, and the conveyed object is moved toward the end of the movement range (forward end or backward end). Then, after the elapse of the first time, it is detected whether or not an abnormality has occurred in the belt by detecting the driving state of the motor. Specifically, when the motor drive is stopped after the first time has elapsed, it can be determined that the movement of the conveyed object (motor drive) is regulated by the stopper, and thus an abnormality occurs in the belt. Judge that it is not. When there is no abnormality in the belt, a process for moving the conveyed object to the target position is performed. On the other hand, if the driving of the motor does not stop after the first time has elapsed, it can be determined that the movement of the conveyed object (motor driving) is not restricted by the stopper, and therefore it is determined that an abnormality has occurred in the belt. In the above conveying apparatus, it is possible to detect that an abnormality has occurred in the belt without requiring a sensor for detecting whether or not the object to be conveyed is positioned at the forward end or the backward end.

The side view which shows typically the structure of the component mounting machine of an Example. The side view which shows typically the structure of the cassette supply apparatus with which the component mounting machine of an Example is equipped. The figure which shows the flowchart of the process which moves the table in which a cassette is mounted to a target position in the component mounting machine of an Example. FIG. 6 is an example of a timing diagram illustrating a change over time in the position of the table when a process of moving the table to a target position is executed in the component mounter of the embodiment.

  The main features of the embodiments described below are listed. The technical elements described below are independent technical elements and exhibit technical usefulness alone or in various combinations, and are limited to the combinations described in the claims at the time of filing. It is not a thing.

(Characteristic 1) In the transport device disclosed in the present specification, the first time is set in advance as the first drive time required for the object to be transported to move from the current position to the forward end or the backward end. It may be a time obtained by adding the second driving time. According to such a configuration, the motor is driven for a time that is appropriately longer than the time required for the conveyed object to move to the forward end or the backward end, and the time until the timeout of the first drive process is appropriately controlled. Can do.

(Characteristic 2) In the transport device disclosed in this specification, the control device determines whether the transported object is positioned at the forward end and whether the transported object is positioned at the backward end based on the driving amount of the motor. May be detectable. Further, in the first driving process, the motor may be driven so that the belt moves in a direction closer to the distance from the current position of the conveyed object between the forward end and the backward end. According to such a configuration, the time required for the first drive process can be shortened, and the conveyed object can be moved to the target position in a short time.

(Characteristic 3) The conveyance device disclosed in the present specification may be a cassette supply device that supplies a cassette for storing electronic components to a mounting machine. The conveyed object may be a table on which a cassette is placed. The mounting machine may include a suction nozzle that sucks an electronic component and a mounting head that is detachable from the cassette and mounts the electronic component sucked by the suction nozzle on a circuit board. The transport device may further include an electronic component supply device that supplies electronic components to the cassette. The mounting head may be detachable from the cassette at the forward end, and the electronic component supply device may be able to supply the electronic component to the cassette at the target position.

  Hereinafter, the component mounter 10 according to the first embodiment will be described. The component mounter 10 is a device for mounting the electronic component 4 on the circuit board 2. The component mounter 10 is also referred to as a surface mounter or a chip mounter. Usually, the component mounting machine 10 is provided together with a solder printer, other component mounting machines, and a board inspection machine, and constitutes a series of mounting lines.

  1 includes a plurality of component feeders 12, a feeder holding unit 14, a mounting head 16, an imaging unit 20, a moving device 18 that moves the mounting head 16 and the imaging unit 20, and a board conveyor. 26, an operation panel 28, a controller 30, and a cassette supply device 32 (shown in FIG. 2).

  Each of the plurality of component feeders 12 accommodates a plurality of electronic components 4. The component feeder 12 is detachably attached to the feeder holding portion 14 and supplies the electronic component 4 to the mounting head 16. The specific configuration of the component feeder 12 is not particularly limited. Each component feeder 12 is, for example, a tape feeder that accommodates a plurality of electronic components 4 in a wound tape shape, a tray feeder that accommodates a plurality of electronic components 4 on a tray, or a plurality of electronic components 4 in a container. Any of the bulk type feeders that accommodates the ink at random.

  The moving device 18 moves the mounting head 16 and the imaging unit 20 between the component feeder 12 and the circuit board 2. The moving device 18 of the present embodiment is an XY robot that moves the moving base 18a in the X direction and the Y direction. The moving device 18 includes a guide rail that guides the moving base 18a, a moving mechanism that moves the moving base 18a along the guide rail, a motor that drives the moving mechanism, and the like. The moving device 18 is disposed above the component feeder 12 and the circuit board 2. The mounting head 16 and the imaging unit 20 are attached to the moving base 18a. The mounting head 16 and the imaging unit 20 are moved by the moving device 18 above the component feeder 12, above the circuit board 2, and above a cassette supply device 32 described later.

  The mounting head 16 includes a suction nozzle 6 that sucks the electronic component 4. The suction nozzle 6 can be attached to and detached from the mounting head 16. The suction nozzle 6 is attached to the mounting head 16 so as to be movable in the vertical direction (Z direction in the drawing). The suction nozzle 6 is configured to move up and down in the vertical direction by an actuator (not shown) accommodated in the mounting head 16 and to suck the electronic component 4. In order to mount the electronic component 4 on the circuit board 2 by the mounting head 16, first, the mounting head 16 is moved to the component suction position by the moving device 18. Next, the suction nozzle 6 is moved downward until the lower surface (suction surface) of the suction nozzle 6 contacts the electronic component 4 housed in the component feeder 12. Next, the electronic component 4 is sucked by the suction nozzle 6 and the suction nozzle 6 is moved upward. Next, the mounting head 16 is moved to the component mounting position by the moving device 18 and positioned with respect to the circuit board 2. Then, the electronic component 4 is mounted on the circuit board 2 by lowering the suction nozzle 6 toward the circuit board 2. As will be described later, the mounting head 16 is also configured to be detachable from a cassette 40 (shown in FIG. 2) that houses the electronic component 4. The mounting head 16 can also mount the electronic component 4 on the circuit board 2 by mounting the cassette 40 and sucking the electronic component 4 accommodated in the cassette 40 to the suction nozzle 6.

  The imaging unit 20 is attached to the moving base 18a. For this reason, when the mounting head 16 moves, the imaging unit 20 also moves together. The imaging unit 20 includes a camera support unit 22 and a camera 24. The camera support 22 is attached to the moving base 18a. A camera 24 is attached to the camera support portion 22. The camera 24 is disposed on the side of the suction nozzle 6 (the Y direction in the drawing). The camera 24 includes a camera control device (not shown) that controls its operation. The operation of the camera 24 is controlled by a camera control device.

  The board conveyor 26 is a device that carries the circuit board 2 into the component mounting machine 10, transfers and positions the circuit board 2 to the component mounting position, and carries out the circuit board 2 from the component mounting machine 10. The substrate conveyor 26 of the present embodiment is constituted by, for example, a pair of belt conveyors, a support device (not shown) that is attached to the belt conveyor and supports the circuit board 2 from below, and a driving device that drives the belt conveyor. Can do. The circuit board 2 is transported in the X direction. The operation panel 28 is an input device that receives an instruction from the worker, and also functions as a display device that notifies the worker of an abnormality in the component mounter 10.

  The controller 30 includes a computer having a CPU, a ROM, and a RAM. Although not shown, the component feeder 12, the mounting head 16, the moving device 18, and the operation panel 28 are communicably connected to the controller 30. The controller 30 mounts the electronic component 4 on the circuit board 2 by controlling these parts (12, 16, 18, 28, etc.).

  As shown in FIG. 2, the cassette supply device 32 includes a belt 34, a motor 36, a table 38, a cassette 40, two stoppers 42 f and 42 r, a control device 44, and an electronic component supply device 46. Yes. In the following, the positive x direction in FIG. 2 is referred to as the forward end direction, and the negative x direction is referred to as the backward end direction. Of the transport range (movement range) of the table 38, the end in the positive x direction is the forward end F and the table 38 is moved. The end in the negative x direction of the range is referred to as the backward end R. The position where the cassette supply device 32 is disposed is not particularly limited, and is provided between the forward end F and the backward end R. Since the cassette 40 can be attached to and detached from the mounting head 16 at the forward end F, the cassette supply device 32 is arranged at a position that does not prevent the cassette 40 from being attached to and detached from the mounting head 16 at the forward end F.

  The belt 34 is formed in a ring shape, and spans between the drive shaft 35a and the driven shaft 35b. The drive shaft 35a is disposed on the backward end R side, and the driven shaft 35b is disposed on the forward end F side. In a state where the belt 34 is stretched over the drive shaft 35a and the driven shaft 35b, the belt 34 has a rounded rectangular shape when viewed along the y direction in the drawing.

  The motor 36 is connected to the drive shaft 35a. When the motor 36 rotates, the drive shaft 35a rotates and the belt 34 rotates. That is, the belt 34 is rotationally driven by the motor 36 and operates like a belt conveyor. For example, a stepping motor is used as the motor 36. The rotation amount of the motor 36 is detected by an encoder (not shown), and the output of the encoder is input to the control device 44. The control device 44 can specify the driving amount of the motor 36, the position of the table 38, and the like from the output of the encoder.

  The table 38 (an example of the object to be conveyed) is conveyed between the forward end F and the backward end R by the belt 34. That is, the table 38 is placed on the upper surface of the belt 34 and fixed to the belt 34. For this reason, when the belt 34 is rotated clockwise, the table 38 is conveyed in the forward direction. When the belt 34 rotates counterclockwise, the table 38 is conveyed in the backward direction. A cassette 40 can be placed on the upper surface of the table 38.

  The cassette 40 can accommodate a plurality of electronic components 4. The cassette 40 is configured to be detachable from the mounting head 16 at the forward end F. When the cassette 40 containing the electronic components 4 is mounted on the mounting head 16, the mounting head 16 takes out the electronic components 4 one by one from the cassette 40 and sucks them onto the suction nozzle 6, and the sucked electronic components 4 are picked up by the circuit board. 2 can be implemented.

  The conveyance range of the table 38 is regulated by two stoppers 42f and 42r. In other words, the stopper 42f disposed at the forward end F contacts the table 38 when the table 38 is transported to the forward end F, thereby restricting its movement so that the table 38 does not advance further. Further, the stopper 42r disposed at the retreating end R contacts the table 38 when the table 38 is transported to the retreating end R, thereby restricting the movement of the table 38 so as not to retreat further.

  The electronic component supply device 46 supplies the electronic component 4 to the cassette 40 at a target position M described later. As described above, the cassette 40 containing the electronic component 4 is mounted on the mounting head 16, and the electronic component 4 received by the mounting head 16 is mounted on the circuit board 2. When the electronic component 4 in the cassette 40 disappears, at the forward end F, the cassette 40 is detached from the mounting head 16 and placed on the table 38. Thereafter, the cassette 40 is conveyed (moved) to the target position M as the belt 34 rotates, and the electronic component 4 is replenished by the electronic component supply device 46 at the target position M. The cassette 40 is prepared for each type of electronic component 4 and can be replaced by the operator at the retracted end R. In addition, a conventionally well-known thing can be used for the electronic component supply apparatus 46, and the aspect in which the electronic component supply apparatus 46 supplies the electronic component 4 to the cassette 40 is not restricted to said structure.

  Next, a process in which the control device 44 of the cassette supply apparatus 32 conveys the table 38 (cassette 40) and a process of detecting an abnormality in the belt 34 will be described with reference to FIGS. The control device 44 controls driving of the motor 36. The control device 44 detects whether the table 38 is located at the forward end F and whether it is located at the backward end R from the driving amount of the motor 36.

  The control device 44 executes a first drive process, a belt abnormality detection process, and a second drive process. The control device 44 moves the belt 34 in either the forward end direction or the backward end direction in the first drive processing. For convenience of explanation, the control device 44 advances the belt 34 in the first drive processing. It shall be moved in the end direction. Further, it is assumed that the initial position of the table 38 (the position before the table 38 is moved to the target position M by the cassette supply device 32) is between the forward end F and the target position M. In the first drive process, the control device 44 is configured to drive the motor 36 so that the belt 34 moves in a direction closer to the distance from the table 38 between the forward end F and the backward end R. May be.

  When the target position M is input from the controller 30 of the component mounter 10 to the cassette supply device 32 (t0), the control device 44 starts the first drive process. In the first drive process, the controller 44 rotates the belt 34 by driving the motor 36 in the forward end direction for a first time T1 that is longer than the time required for the table 38 to move to the forward end F. The table 38 is moved in the forward end direction (S10). The first time T1 is a time obtained by adding the first drive time t1 required for the table 38 to move from the current position to the forward end F and the preset second drive time t2. . Since the control device 44 stores the current position of the table 38 (target position in the previous process), the control device 44 calculates the first drive time t1 based on the current position of the table 38.

  Next, the control device 44 performs belt abnormality detection processing. When the drive of the motor 36 is stopped during the first drive process (that is, during the first time T1) (S12: YES), the controller 44 moves forward by the table 38 coming into contact with the stopper 42f. It determines with having stopped to the end F, and progresses to the process of step S14. That is, when the belt 34 is normal, when the motor 36 is driven for the first time T1, the table 38 is in contact with the stopper 42f. When the table 38 comes into contact with the stopper 42f, the belt 34 cannot rotate further in the forward end direction, so the load increases and the rotation of the motor 36 also stops. Therefore, when the rotational drive of the motor 36 is stopped, no abnormality has occurred in the belt 34 and the table 38 can be specified as being positioned at the forward end F. On the other hand, when the drive of the motor 36 does not stop during the first drive process (S12: NO), the control device 44 determines that an abnormality has occurred in the belt 34 (S20). That is, when an abnormality occurs in the belt 34, a slip occurs between the belt 34 and the drive shaft 35a, and the belt 34 does not rotate. For this reason, the table 38 is not conveyed and does not contact the stopper 42f. The motor 36 continues to rotate even after the first time T1 has elapsed. Therefore, if the motor 36 does not stop during the first drive process, it can be determined that an abnormality has occurred in the belt 34. The abnormality occurring in the belt 34 is, for example, cutting of the belt 34 or the like. If the control device 44 determines in step S20 that an abnormality has occurred in the belt 34, the control device 44 transmits a notification to the controller 30 that an abnormality has occurred and ends the process. The controller 30 can instruct the operator to take appropriate measures, for example, by displaying on the operation panel 28 that an abnormality has occurred. If YES in step S12, the control device 44 sets absolute coordinates with the position of the table 38 (in this embodiment, the forward end F) as the origin position (S14), and proceeds to the subsequent second drive process.

  In the second driving process, the control device 44 drives the motor 36 so as to move the belt 34 in the backward end direction during the second time T2 based on the absolute coordinates set in step S14 (S16). The process of step S16 is performed after a predetermined period after the process of step S14. That is, there is a predetermined period between the end time of the first time T1 and the start time of the second time T2. The predetermined period is, for example, a period until the cassette 40 placed on the table 38 is mounted on the mounting head 16 or a period until the cassette 40 is detached from the mounting head 16 and placed on the table 38. It is. In addition, the process of step S16 may be performed immediately after the process of step S14. Note that the second time T2 is the time required to move the table 38 from the origin position to the target position M. The control apparatus 44 will complete | finish a process, if the process of step S16 is performed.

  In the component mounter 10 described above, when the belt 34 is normal, when the motor 36 is driven, the belt 34 rotates in conjunction with the motor 36. Therefore, the table 38 moves in the forward end direction and abuts against the stopper 42 during the first time T1. At this time, since the load on the motor 36 is increased by restricting the movement of the table 38, the rotation of the motor 36 is stopped. The control device 44 can detect that the table 38 is positioned at the forward end F by detecting the driving state of the motor 36 (that is, the driving of the motor 36 is stopped).

  On the other hand, when an abnormality occurs in the belt 34, for example, when the belt 34 is cut, the belt 34 is not interlocked even if the motor 36 rotates, and the table 38 does not move. For this reason, even if the first time T1 elapses, the table 38 does not move in the forward end direction (it is not positioned at the forward end F), so the motor 36 continues to be driven, and the rotation of the motor 36 is Do not stop. Accordingly, the control device 44 detects that the belt 34 has malfunctioned by detecting the driving state of the motor 36 when the first time T1 has elapsed (that is, the motor 36 is continuously driven). can do.

  When the table 38 is located at the forward end F or the backward end R, the control device 44 sets absolute coordinates with the position as the origin position. Every time the table 38 is moved to the target position M, the origin of the table 38 is returned and the absolute coordinates are set, so that the accuracy of positioning the table 38 at the target position M can be improved. Further, unlike the prior art, there is no need for a sensor for detecting that the conveyed object is located at the forward end F or the backward end R. Therefore, it is not necessary to perform an operation for arranging the sensor or an operation for routing the wiring, and a space for the sensor or the wiring is not necessary, so that the cost can be reduced.

  As mentioned above, although the Example of the technique which this specification discloses was described in detail, these are only illustrations and do not limit a claim. The technology described in the claims includes various modifications and changes of the specific examples illustrated above.

  For example, in the present embodiment, the component mounter has been described as an example of a device capable of detecting a belt abnormality, but may be used for devices other than the component mounter.

  In the present embodiment, the process of moving the table 38 from the current position (position between the forward end F and the backward end R) to the target position M has been described. However, the current position of the table 38 is the forward end F or the backward position. Even if it is located at the end R, the above-described processing may be executed by the control device 44. If comprised in this way, even if the present position of the table 38 is the forward end F or the backward end R, the control apparatus 44 will perform a 1st drive process, whenever the target position M is input, and the table 38 will be performed. Can be reliably returned to the origin. Therefore, the positioning accuracy with respect to the target position M of the table 38 can be further improved. In the first drive process that is repeatedly performed, the motor may be driven to move the belt in the forward end direction, or the motor may be driven to move the belt in the backward end direction.

  The technical elements described in this specification or the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology illustrated in the present specification or the drawings achieves a plurality of objects at the same time, and has technical utility by achieving one of the objects.

2: Circuit board 4: Electronic component 6: Suction nozzle 10: Component mounting machine 12: Component feeder 14: Feeder holding unit 16: Mounting head 18: Moving device 18a: Moving base 20: Imaging unit 22: Camera support unit 24: Camera 26: substrate conveyor 28: operation panel 30: controller 32: cassette supply device 34: belt 36: motor 38: table 40: cassette 42: stopper 44: control device 46: electronic component supply device

Claims (4)

A transport device capable of detecting an abnormality of a belt that transports an object to be transported placed on an upper surface,
A motor for driving the belt;
Two stoppers arranged at the forward end and the backward end of the belt, respectively, for restricting the movement of the conveyed object;
A control device that controls driving of the motor and detects whether the object to be conveyed is positioned at the forward end or the backward end from the driving amount of the motor;
The controller is
When the object to be conveyed is moved to a target position set between the forward end and the backward end, first, a time longer than the time required for the object to move to the forward end or the backward end is longer. A first driving process for moving the belt in a forward end direction or a backward end direction by driving the motor for a period of one time;
While the driving of the motor is stopped during the first driving process, it is determined that the conveyed object is stopped at the forward end or the backward end by contacting the stopper, A belt abnormality detection process for determining that an abnormality has occurred in the belt when the driving of the motor does not stop during the first drive process;
When it is determined in the belt abnormality detection process that the conveyed object is positioned at the forward end or the backward end, the position required to move the conveyed object to the target position using the position as the origin position. And a second driving process for driving the motor so as to move the belt in a direction opposite to the operation direction of the first driving process for a period of two.   The first time is a time obtained by adding a first driving time required for the conveyed object to move from its current position to the forward end or the backward end and a preset second driving time. The transfer device according to claim 1, wherein The control device can detect both whether the transported object is positioned at the forward end and whether the transported object is positioned at the retracted end from the driving amount of the motor,
The first drive process drives the motor so that the belt moves toward a direction in which the distance from the current position of the conveyed object is shorter between the forward end and the backward end. Or the conveying apparatus of 2. The transport device is a cassette supply device that supplies a cassette for storing electronic components to a mounting machine,
The transported object is a table on which the cassette is placed,
The mounting machine is
A suction nozzle for sucking the electronic component;
The cassette is detachable, and includes a mounting head for mounting the electronic component sucked by the suction nozzle on a circuit board,
The transfer device
An electronic component supply device for supplying the electronic component to the cassette;
The mounting head is detachable from the cassette at the forward end,
The said electronic component supply apparatus is a conveying apparatus as described in any one of Claims 1-3 which can supply the said electronic component to the said cassette in the said target position.

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