JP5774971B2 - Surface mount apparatus and head drive control method - Google Patents

Description

  The present invention relates to a surface mount device and a head drive control method, and more particularly to a surface mount device including a head and a head drive control method.

  Conventionally, a surface mounting apparatus including a head is known (for example, see Patent Document 1).

  Patent Document 1 includes a component mounting head, a Z-axis drive motor (motor) that drives the head up and down, and a controller (control unit) that controls driving of the head by controlling the Z-axis drive motor. A surface mounting apparatus is disclosed. This surface mount apparatus is configured to perform head load control, which is control for applying a constant drive current to the Z-axis drive motor to apply an appropriate load to the component.

Japanese Patent No. 4708449

  However, in the surface mounting apparatus described in Patent Document 1, when a constant drive current is applied to control the head load, the head load is affected by cogging or gear eccentricity of the Z-axis drive motor (motor). There is a problem that it is difficult to perform control accurately.

  The present invention has been made to solve the above-described problems, and one object of the present invention is to provide a surface mounting apparatus and a head drive control method capable of accurately controlling the load on the head. It is to be.

A surface mounting apparatus according to a first aspect of the present invention includes a component mounting head, a motor that drives the head up and down, a control unit that controls a load applied to the component by controlling the motor current , A storage unit that stores a measurement result of the loss amount of the driving force of the motor according to the lift position, and the control unit previously measures the loss amount of the driving force of the motor according to the lift position of the head and stores it in the storage unit. While the head applies the load to the component, the set value of the motor current for controlling the load based on the measurement result stored in the storage unit is variably controlled according to the lift position of the head. , the load applied to the component is configured to perform a load control of the head so as to be approximately constant regardless of the vertical position of the head Rutotomoni, the driving force of the motor in accordance with the vertical position of the head during operation A measurement result of measuring the loss amount, if the difference between the measurement result stored in the storage unit is greater than a predetermined amount, and is configured to perform control for updating the measurement results.

  In the surface mount device according to the first aspect of the present invention, as described above, the load control of the head is performed by variably controlling the set value of the motor current for controlling the load in accordance with the lift position of the head. By configuring the control unit, even if the cogging or gear eccentricity of the motor occurs due to fluctuations in the head lifting position, the motor driving force varies according to the head lifting position so as to offset these effects. Therefore, the load control of the head can be performed with high accuracy. In particular, in the control for applying a low load to the head, the influence of the cogging of the motor and the gear eccentricity on the load becomes relatively large. Therefore, the present invention capable of accurately controlling the load on the head is effective.

In the surface mount device according to the first aspect, preferably, the control unit variably controls the set value of the motor current according to the loss amount of the driving force of the motor according to the lift position of the head , so that the head During the application of the load to the component, the load control of the head is performed so that the load applied to the component becomes substantially constant regardless of the lift position of the head. According to this structure, the motor is configured so that the actual driving force of the motor obtained by subtracting the loss amount according to the loss amount of the driving force caused by the cogging of the motor, which fluctuates depending on the head lift position, becomes a predetermined magnitude. Since the set value of the current can be variably controlled, the head load can be controlled with higher accuracy.

In this case, it is preferable that the control unit is configured so that the load of the head is a predetermined size and a substantially constant size regardless of the lift position of the head while the head applies a load to the component. The head load is controlled by variably controlling the set value of the motor current according to the amount of loss of the driving force of the motor according to the lift position. With this configuration, the head load can be easily controlled so as to have a predetermined magnitude regardless of the head lift position, so it can be used for multiple types of parts with different heights. It is possible to easily make the load applied to the predetermined size.

In the surface mounting apparatus according to the first aspect described above, preferably, the control unit measures the loss amount of the driving force of the motor according to the lift position of the head while the surface mounting apparatus is in operation, and is operating the surface mounting apparatus. the configuration of the measurement result, as the difference between the measurement result stored in the storage unit is larger than a predetermined amount, performing control to notify based on the control and measurement result to update the measurement results to the user Has been. With this configuration, even when the amount of loss changes even at the same position, for example, when the temperature changes during operation of the surface mount device, the head load can be controlled accurately in accordance with the change in the amount of loss. it can.

In the surface mounting apparatus according to the first aspect , preferably, the control unit is configured to measure a loss amount of the driving force of the motor according to the lift position of the head while moving the head at a constant speed. . With such a configuration, the head moves at a constant speed, so that it is not necessary to consider the force due to the acceleration of the head. Thereby, the loss amount of the driving force of the motor according to the raising / lowering position of the head can be easily measured. Further, since the loss amount can be measured only by moving the head at a constant speed, it is not necessary to use a measurement-dedicated jig. Further, the loss amount can be easily measured during operation of the surface mount apparatus.

In the surface mount device according to the first aspect , preferably, the control unit obtains an average value by measuring a loss amount of the driving force of the motor according to the lift position of the head a plurality of times, and average value of the loss amount. Based on the above, the load control of the head is performed. With this configuration, the loss amount can be calculated more accurately by taking the average value obtained by measuring the loss amount a plurality of times, so that the head load control can be performed with higher accuracy.

A head drive control method according to a second aspect of the present invention includes a step of measuring in advance a loss amount of a driving force of a motor according to a lift position of a head during operation of a surface mount device and storing the loss in a storage unit; The control value of the motor current for controlling the load of the head based on the measurement result stored in the head is variably controlled according to the lift position of the head. A step of controlling the load of the head so that the load applied to the head is substantially constant regardless of the lift position of the head, and the amount of loss of the driving force of the motor according to the lift position of the head during the operation of the surface mount device. A step of updating the measurement result when the difference between the measured measurement result and the measurement result stored in the storage unit is larger than a predetermined amount .

  In the head drive control method according to the second aspect of the present invention, as described above, the load control of the head is controlled by variably controlling the set value of the motor current for controlling the load of the head according to the lift position of the head. By configuring so that, even when the cogging or gear eccentricity of the motor occurs due to the fluctuation of the head lifting position, the motor driving force varies according to the head lifting position so as to offset these effects Therefore, the load control of the head can be performed with high accuracy. In particular, in the control for applying a low load to the head, the influence of the cogging of the motor and the gear eccentricity on the load becomes relatively large. Therefore, the present invention capable of accurately controlling the load on the head is effective.

  According to the present invention, the load control of the head can be performed with high accuracy as described above.

It is the top view which showed the outline of the surface mounting apparatus by 1st Embodiment of this invention. It is the side view which showed the outline of the surface mounting apparatus by 1st Embodiment of this invention. It is the block diagram which showed the structure on the control of the surface mounting apparatus by 1st Embodiment of this invention. It is a control block diagram for demonstrating drive control of the head of the surface mount apparatus by 1st Embodiment of this invention. It is a figure for demonstrating the force which acts on the head of the surface mount apparatus by 1st Embodiment of this invention. It is a figure for demonstrating the control current for performing load control of the head of the surface mount apparatus by 1st Embodiment of this invention. It is a figure for demonstrating the force of the load control of the head of the surface mount apparatus by 1st Embodiment of this invention. It is a flowchart for demonstrating the process of the drive control of the head by the controller of the surface mount apparatus by 1st Embodiment of this invention. It is a timing chart for demonstrating the drive of the head of the surface mount apparatus by 1st Embodiment of this invention. It is a flowchart for demonstrating the measurement process of the loss current by the controller of the surface mount apparatus by 1st Embodiment of this invention. It is the figure which showed the control current for performing the low load control of the head of the surface mount apparatus by 1st Embodiment of this invention. It is a flowchart for demonstrating the process of the drive control of the head by the controller of the surface mount apparatus by 2nd Embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
First, the structure of the surface mounting apparatus 100 according to the first embodiment of the present invention will be described with reference to FIGS.

  As shown in FIGS. 1 and 2, the surface mounting apparatus 100 mounts a component 4 a on the printed circuit board 3 at a predetermined work position after the printed circuit board 3 is conveyed from the X2 direction side to the X1 direction side by a pair of conveyors 2. It is a device to do.

  As shown in FIG. 1, the surface mounting apparatus 100 includes a base 1, a pair of conveyors 2, a head unit 5, a support unit 6, a rail unit 7, a camera unit 8, and a controller 9 (see FIG. 1). 3). Moreover, the some tape feeder 4 for supplying the components 4a is arrange | positioned at the both sides (Y1 direction side, Y2 direction side) of the conveyor 2. FIG. The head unit 5 has a function of acquiring the component 4 a from the tape feeder 4 and mounting the component 4 a on the printed circuit board 3 on the conveyor 2. The controller 9 is an example of the “control unit” in the present invention.

  The pair of conveyors 2 has a function of transporting the printed circuit board 3 in the horizontal direction (X direction). Moreover, the conveyor 2 is comprised so that the printed circuit board 3 in conveyance may be hold | maintained in the state stopped at the mounting operation position.

  The tape feeder 4 holds a reel (not shown) around which a tape holding a plurality of parts 4a at a predetermined interval is wound. The tape feeder 4 is configured to supply the component 4a from the tip of the tape feeder 4 by rotating a reel and sending out a tape that holds the component 4a. Here, the component 4a is a small electronic component such as an IC, a transistor, a capacitor, and a resistor.

  As shown in FIG. 1, the head unit 5 includes a ball nut 51, six heads 52, and a Z-axis drive motor 53 (see FIG. 3). Further, the head unit 5 includes a ball screw shaft 54, a ball nut 55, and a spring 56, as shown in FIG. The head unit 5 is configured to be movable in the X direction along the support portion 6. Specifically, the support unit 6 includes a ball screw shaft 61, an X-axis drive motor 62 that rotates the ball screw shaft 61, and a guide rail (not shown) that extends in the X direction. Accordingly, the head unit 5 is moved in the X direction together with the ball nut 51 to which the ball screw shaft 61 is screwed. The Z-axis drive motor 53 is an example of the “motor” in the present invention.

  As shown in FIG. 2, the six heads 52 are arranged in a row along the X direction on the lower surface side (Z1 direction side) of the head unit 5. A nozzle 52a is attached to the tip of each head 52 (end on the Z1 direction side). Each nozzle 52a is configured to be able to suck and hold the component 4a supplied from the tape feeder 4 by the negative pressure generated at the tip of the nozzle 52a by a negative pressure generator (not shown). ing.

  Each head 52 is configured to be movable up and down (moved in the Z-axis direction) with respect to the head unit 5. Specifically, the head 52 is configured to be able to move up and down between a lowered position when the component 4a is sucked or mounted (mounted) and a raised position when the component 4a is conveyed or imaged. As shown in FIG. 5, the head 52 is moved in the Z direction together with a ball nut 55 that is screwed to the ball screw shaft 54 when the Z-axis drive motor 53 is driven. The head 52 is pulled upward (Z2 direction side) by a spring 56. Thereby, the head 52 is configured to be pulled upward (Z2 direction side) by the spring 56 when the surface mounting apparatus 100 stops. The head 52 is configured to be individually driven up and down by a Z-axis drive motor 53 provided for each head 52. The head 52 is configured to be rotatable around the central axis of the nozzle 52a by an R-axis drive motor (not shown).

  The support portion 6 is configured to be movable in the Y direction orthogonal to the X direction along a pair of rail portions 7 fixed on the base 1. Specifically, as shown in FIG. 1, the rail portion 7 includes a guide rail 71 that supports both end portions (X direction) of the support portion 6 so as to be movable in the Y direction, a ball screw shaft 72 that extends in the Y direction, And a Y-axis drive motor 73 that rotates the ball screw shaft 72. Further, the support portion 6 is provided with a ball nut 63 into which the ball screw shaft 72 is screwed. Thereby, the head unit 5 is moved on the base 1 along the Y direction. Therefore, the head unit 5 can move to an arbitrary position on the base 1 along the XY plane.

  The camera unit 8 is fixedly installed on the upper surface of the base 1. Further, the camera unit 8 is configured to take an image of the component 4a adsorbed by the nozzle 52a of each head 52 from the lower side in order to recognize the adsorption of the component 4a prior to the mounting of the component 4a.

  The controller 9 is mounted on the surface mounting apparatus 100 with a computer as a component. Further, the controller 9 is configured to drive and control the X-axis drive motor 62, the Y-axis drive motor 73, and the Z-axis drive motor 53 in accordance with a program stored in advance, so that the component 4a is mounted on the printed circuit board 3. ing. Specifically, the controller 9 moves the head unit 5 above the tape feeder 4 and sucks the component 4 a by the nozzle 52 a of each head 52. That is, after the head 52 (nozzle 52a) is disposed above the tape feeder 4, the head 52 is driven up and down, and negative pressure is supplied to the tip of the nozzle 52a at a predetermined timing, so that the component 4a becomes the nozzle 52a. It is taken out while adsorbed on the tip.

  Then, the controller 9 moves the head unit 5 onto the printed board 3. During this movement, the camera unit 8 picks up images of the parts 4a sucked by the nozzles 52a of the heads 52 through the head unit 5 above the parts recognition camera unit 8. Based on the captured image, the mounting position of the component 4a sucked by each head 52 (nozzle 52a) is corrected. When the head unit 5 reaches the printed circuit board 3, each head 52 is driven to move up and down, and the suctioned component 4 a is stopped when the supply of negative pressure to the nozzle 52 a is stopped at a predetermined timing. 3 is implemented.

  Here, in the first embodiment, the controller 9 variably controls the current supplied to the Z-axis drive motor 53 for controlling the load according to the raising / lowering position (Z-direction position) of the head 52, thereby controlling the head 52. It is comprised so that load control may be performed. Specifically, the controller 9 determines the upper limit of the current supplied to the Z-axis drive motor 53 based on the value of the loss current corresponding to the loss amount of the driving force of the Z-axis drive motor 53 according to the lift position of the head 52. The load of the head 52 is controlled by variably controlling the value (second current limit value). The load control is performed in order to apply an appropriate load to the component 4a when the head 52 picks up the component 4a from the tape feeder 4 or mounts the component 4a on the printed circuit board 3. This load control is performed using the upper limit value (second current limit value) of the current supplied to the Z-axis drive motor 53. That is, during load control, the upper limit value (second current limit value) of the current is supplied to the Z-axis drive motor 53. As shown in FIG. 3, the controller 9 includes a CPU (central processing unit) 91, a storage unit 92, a current amplification unit 93, a drive current detection unit 94, a speed reading unit 95, and a position reading unit 96. Including. The CPU 91 includes a motor control calculation unit 91a, a current control unit 91b, a current command control unit 91c, a speed control unit 91d, and a position control unit 91e as software functions. The second current limit value is an example of the “motor current set value” in the present invention.

  The motor control calculation unit 91a is configured to control the Z-axis drive motor 53 in order to drive the head 52 in accordance with a predetermined mounting program. Specifically, the motor control calculation unit 91a calculates and sets the lowering target position of the head 52 when the component 4a is attracted and mounted based on various data such as component data (thickness) stored in the storage unit 92. In addition, various determination processes are performed, and a control signal is output to the current control unit 91b according to the results. Further, when the head 52 is lowered, the motor control calculation unit 91a compares the drive current value with a predetermined threshold value based on a signal from the drive current detection unit 94 after a lapse of a required time for the head 52 to move. It is configured to determine whether or not the head 52 has reached the position and stop the Z-axis drive motor 53 based on the determination result.

  Further, the motor control calculation unit 91 a is configured to calculate a loss current corresponding to the amount of loss of the driving force of the Z-axis drive motor 53 according to the lift position of the head 52 and store it in the storage unit 92. . In addition, the motor control calculation unit 91a sets the upper limit value (second current limit value) of the current supplied to the Z-axis drive motor 53 based on the loss current value of the Z-axis drive motor 53 stored in the storage unit 92. It is configured to be variably controlled.

  The current control unit 91b is configured to determine the drive current value of the Z-axis drive motor 53 based on a control signal from the motor control calculation unit 91a. Specifically, the current control unit 91b outputs a signal corresponding to the determined drive current value to the current amplification unit 93 via the current command control unit 91c. Then, the current amplification unit 93 supplies the drive current I corresponding to the signal output from the current control unit 91b to the Z-axis drive motor 53 via the drive current detection unit 94.

  The current command control unit 91c is configured to limit the drive current I by determining an upper limit value of current in order to prevent supply of overcurrent. Specifically, when the current value corresponding to the signal output from the current control unit 91b exceeds the upper limit value, the current command control unit 91c replaces the signal output from the current control unit 91b with the current. A signal corresponding to the upper limit value is output to the current amplifier 93. As a result, the drive current I supplied from the current amplifier 93 to the Z-axis drive motor 53 is limited. That is, it is possible to prevent the drive current I larger than the predetermined upper limit value from being supplied to the Z-axis drive motor 53. As the upper limit value of the current, there are two upper limit values, ie, a first current limit value that is a reference limit value and a second current limit value that is lower than the first current limit value. The current command control unit 91c switches between these two upper limit values at a predetermined timing during the head operation. As a result, it is possible to prevent an excessive current from being supplied to the Z-axis drive motor 53, and thus it is possible to accurately control the load on the head 52 while preventing an excessive increase in the load on the head 52. Is possible.

  Here, the first current limit value is set so as to correspond to the current value necessary for the head 52 to normally move up and down. The second current limit value is set so as to correspond to a current value necessary for load control of the head 52.

  The speed reading unit 95 and the position reading unit 96 are configured to detect a current driving speed and a driving position, respectively, based on a signal output from a rotary encoder 53a provided in the Z-axis drive motor 53. The speed control unit 91d is configured to output a deviation between the detected value of the driving speed detected by the speed reading unit 95 and the target value to the motor control calculation unit 91a. The position control unit 91e is configured to output a deviation between the detected value of the drive position detected by the position reading unit 96 and the target value to the motor control calculation unit 91a. The motor control calculation unit 91a feedback-controls the Z-axis drive motor 53 by outputting a control signal to the current control unit 91b so that the deviations output from the speed control unit 91d and the position control unit 91e are eliminated. It is configured. The drive current detection unit 94 is configured to detect a drive current value of the Z-axis drive motor 53 and output a signal corresponding to the current value to the motor control calculation unit 91a.

  Next, with reference to FIGS. 4 to 7, the load control of the head 52 performed by the controller 9 in the surface mounting apparatus 100 will be described. The load control is performed when the component 4a is sucked from the tape feeder 4 by the head 52 and when the component 4a is mounted (mounted) on the printed circuit board 3.

  As shown in FIG. 4, the controller 9 compares the current command value for driving the head 52 (nozzle 52a) with the second current limit value calculated by the following equation (1), and the smaller one is obtained. Is controlled to output a drive current I having a value of. When the current command value is equal to the second current limit value, the controller 9 performs control so as to output the drive current I having the same value. Here, in a state where the tip of the head 52 (nozzle 52a) is in contact with the component 4a and the displacement of the head 52 is restricted, the second current limit value is equal to or less than the current command value, so the drive current I is Current limit value. Note that the loss current varies depending on the lift position (Z-direction position) of the head 52 as shown in FIG. This is because the amount of loss of the driving force of the Z-axis drive motor 53, which will be described later, differs according to the lift position of the head 52 (see FIG. 7). If the load of the head 52 is constant, the load current (see FIG. 6) is also constant. Thereby, the second current limit value varies depending on the lift position of the head 52.

  Second current limit value = load current + loss current (1)

  Then, the controller 9 supplies the drive current I to the Z-axis drive motor 53 by performing current feedback control so as to follow the output drive current I. As a result, the Z-axis drive motor 53 drives the head 52 with a driving force corresponding to the supplied driving current I (see the following formula (2) in the case of ball screw driving).

Driving force = 2π · nl · Kt · I / L (2)
In equation (2), π represents the circular ratio, and nl represents the ball screw efficiency. Kt is a motor torque constant, I is an electric current, and L is a lead of a ball screw (a distance traveled in the axial direction by rotating the screw once).

  The head 52 is driven with a loss amount subtracted from the driving force of the Z-axis drive motor 53 to generate a load in the Z1 direction (see equation (3) below). Here, as shown in FIG. 5, the loss amount includes a force (cogging force) due to cogging of the Z-axis drive motor 53, gravity, a force of the spring 56, and a frictional force (see the following formula (4)). Yes. Note that the force due to cogging of the Z-axis drive motor 53 (cogging force) varies depending on the rotational position of the Z-axis drive motor 53. That is, the force due to cogging of the Z-axis drive motor 53 differs depending on the lift position (Z-direction position) of the head 52 driven by the Z-axis drive motor 53. Gravity is a force that acts uniformly in the load direction (Z1 direction) according to the weight of the head 52 and the like. The force of the spring 56 is a force acting in the Z2 direction according to the lift position of the head 52. The frictional force is a force generated at a position where the ball screw shaft 54 and the ball nut 55 are screwed together and acting in the direction opposite to the moving direction of the head 52. Accordingly, as shown in FIG. 7, the amount of loss of the driving force of the Z-axis drive motor 53 varies depending on the lift position of the head 52.

Driving force-loss amount = load (3)
Loss amount = Z-axis drive motor cogging force + gravity + spring force + friction force (4)

  Further, the controller 9 is configured to measure and acquire a loss current with respect to the lift position of the head 52 in advance. Specifically, the controller 9 measures the loss current according to the lift position of the head 52 while lowering the head 52 at a constant speed by the Z-axis drive motor 53. Specifically, by lowering the head 52 at a constant speed, a load accompanying acceleration is not applied, and the head 52 is not in contact with the component 4a. (Load) = 0. As a result, the driving force of the Z-axis drive motor 53 becomes equal to the loss amount of the Z-axis drive motor 53 based on the above equation (3). That is, the current applied to the Z-axis drive motor 53 is equal to the loss current. Therefore, the controller 9 acquires a loss current corresponding to the lift position of the head 52 by measuring the current applied to the Z-axis drive motor 53.

  Next, with reference to FIG. 8 and FIG. 9, the flow of the drive control processing of the head 52 by the controller 9 of the surface mounting apparatus 100 will be described. This control is executed both when the component 4a is sucked from the tape feeder 4 by the head 52 and when the component 4a is mounted (mounted) on the printed circuit board 3. In the following description, when the component 4a is sucked Will be described as an example.

  In step S1, the controller 9 calculates and sets the lowering target position of the head 52, which is the height position of the head 52 when the component 4a is attracted, based on data such as the component size (thickness). Further, the controller 9 calculates and sets a theoretical PTP (point-to-point) time (required time until the head 52 reaches the lowering target position after starting the lowering) based on the set lowering target position. In step S2, the controller 9 sets a time-out period (a period of time until the determination of whether or not the head 52 has reached the lowering target position after starting the lowering).

  The lowering target position may be a theoretical height position at which the tip of the nozzle 52a starts to contact the upper surface of the component 4a held at the component extraction position of the tape feeder 4, but in the first embodiment, From the height position (theoretical target position) at which the tip of the nozzle 52a starts to contact the upper surface of the component 4a so that the head 52 can be stopped with the nozzle 52a securely contacting the component 4a. Also, the height position that reaches slightly downward is set as the lowering target position.

  Next, the controller 9 sets the upper limit value of the current to the first current limit value in step S3. Then, in step S4 (at T0 in FIG. 9), the controller 9 drives the Z-axis drive motor 53 to start the head 52 descending, and at the same time, a timer (not shown) for timing the theoretical PTP time and timeout time. Is activated.

  After the head 52 starts to descend, the controller 9 determines in step S5 whether or not the acceleration drive of the Z-axis drive motor 53 has been completed. If it is determined that the operation has not been completed, the controller 9 continues the downward PTP movement of the head 52 in step S13, and repeats the processing in steps S5 and S13 until the acceleration drive of the Z-axis drive motor 53 is completed. When the acceleration drive of the Z-axis drive motor 53 is completed, the controller 9 switches the upper limit value of the current in the positive direction from the first current limit value to the second current limit value in step S6 (at T1 in FIG. 9).

  Here, in the first embodiment, the controller 9 reads out the second current limit value based on the loss current corresponding to the elevation position (Z direction position) of the head 52 from the storage unit 92 in step S7. In step S8 (from T1 to Te in FIG. 9), the controller 9 sets the second current limit value corresponding to the current position of the head 52 as the upper limit value of the current.

  In step S9, the controller 9 determines whether or not the theoretical PTP time has been completed. If it is determined that it has not been completed, the controller 9 continues the downward PTP movement of the head 52 in step S14 and returns to step S7.

  When the theoretical PTP time is completed (when Te in FIG. 9 has elapsed), the controller 9 compares the drive current value with the threshold value (second current limit value) in step S10, and the nozzle 52a comes into contact with the component 4a. It is determined whether or not. In other words, under the feedback control as described above, the drive current value of the Z-axis drive motor 53 increases when the tip of the nozzle 52a abuts against the component 4a and the displacement of the head 52 is restricted. It is possible to determine whether or not the head 52 is in contact with the component 4a by comparing (second current limit value).

  If it is determined that the head 52 is in contact with the component 4a, the controller 9 turns on the movement (downward) completion flag in step S11. Thereafter, in step S12, the controller 9 controls the Z-axis drive motor 53 to stop the drive of the head 52, and ends the descending control of the head 52. After the end of this flowchart, the controller 9 raises the head 52 by driving the Z-axis drive motor 53 in reverse so as to pick up the sucked component 4a from the tape feeder 4.

  On the other hand, if it is determined that the head 52 is not in contact with the component 4a, the controller 9 determines whether or not the head 52 is in contact with the component 4a based on the position detected by the position reading unit 96 in step S15. Determine whether. Specifically, the controller 9 determines whether or not the tip of the nozzle 52a has reached the theoretical height position of the surface of the component 4a. If it is determined that it has reached, the process proceeds to step S11. If it is determined that the time has not been reached, the controller 9 determines in step S16 whether or not a timeout time has elapsed. If it is determined that the timeout time has not elapsed, the controller 9 continues the downward PTP movement of the head 52 in step S18 and returns to step S10. If it is determined that the timeout time has elapsed, the controller 9 executes a predetermined error notification process such as displaying on the display unit (not shown) that an error has occurred in step S17, and proceeds to step S11.

  Next, the driving of the head 52 controlled by the controller 9 as described above will be described with reference to the timing chart of FIG.

  First, the head 52 starts to descend at time T0. At this time, the upper limit value of the current of the Z-axis drive motor 53 is set to the first current limit value. Further, when the current for acceleration driving is supplied to the Z-axis drive motor 53, the head 52 starts to descend (acceleration driving).

  When the head 52 reaches a predetermined speed and the acceleration drive is finished (at time T1), the drive of the head 52 is switched to the constant speed drive, and the upper limit value of the current is changed from the first current limit value to the lift position (Z The second current limit value varies depending on the direction position. Further, the driving of the head 52 is switched from the constant speed driving to the deceleration driving at a predetermined timing before the theoretical PTP time elapses.

  When the nozzle 52a comes into contact with the component 4a as the head 52 moves down (at the time Th), the displacement of the head 52 is restricted, and the drive current value of the Z-axis drive motor 53 increases from the Th time. At this time, since the upper limit value of the current is set to the second current limit value, the increase in the drive current value is limited to the second current limit value.

  Then, when the theoretical PTP time has elapsed (at time Te), the drive current value at that time is compared with a threshold value (second current limit value), and the drive current value has reached the threshold value as shown in FIG. After the drive of the head 52 (Z-axis drive motor 53) is stopped, the drive is switched to ascending drive. In the first embodiment, since the height position at which the tip of the nozzle 52a reaches slightly below the height position of the upper surface of the component 4a is set as the lowering target position, the head 52 is actually lowered. Contact with the component 4a at a position higher than the target position restricts the displacement. Therefore, normally, the drive current I starts to increase from the Th point before the theoretical PTP time elapses, and the drive current value reaches the threshold (second current limit value) at the Te point when the theoretical PTP time has elapsed.

  Next, with reference to FIG. 10, the flow of the measurement process of the loss current by the controller 9 of the surface mounting apparatus 100 will be described.

  When the operation for starting the operation is performed by the user, the controller 9 starts the automatic operation of the surface mounting apparatus 100 in step S31. In step S32, the controller 9 resets the current measurement timer. Moreover, the controller 9 conveys the printed circuit board 3 to a mounting position in step S33. In step S34, the controller 9 mounts the component 4a on the printed circuit board 3, and then carries the printed circuit board 3 out of the mounting position.

  Next, in step S35, the controller 9 determines whether or not the current measurement timer has passed a predetermined time (for example, 30 minutes). If the predetermined time has not elapsed, the process returns to step S33. If the predetermined time has elapsed, the controller 9 measures the loss current in step S36. That is, the controller 9 measures the loss current every predetermined time (for example, 30 minutes). Next, the controller 9 compares the stored value of the loss current stored in the storage unit 92 with the measured value of the loss current. In other words, the controller 9 compares the loss current value currently used to determine the second current limit value with the measured loss current value.

  In step S38, the controller 9 determines whether or not the difference between the stored loss current value and the measured value is greater than or equal to a predetermined difference. For example, the controller 9 determines whether or not the measured value has a difference of 10% or more of the stored value with respect to the stored value of the loss current. If there is no difference greater than the predetermined difference, the process returns to step S32. If there is a difference greater than or equal to the predetermined difference, the controller 9 displays on the display unit (not shown) that the difference between the stored value of the loss current and the measured value is greater than or equal to the predetermined difference and notifies the user in step S39. . Then, in step S40, the controller 9 determines whether or not the user's operation for updating the loss current has been accepted. If no update operation is accepted, the process returns to step S32. If the update operation is accepted, the controller 9 updates the value of the loss current and stores it in the storage unit 92 in step S41. Thereafter, the process returns to step S32.

  In the first embodiment, the load control of the head 52 is performed by variably controlling the upper limit value (second current limit value) of the current supplied to the Z-axis drive motor 53 according to the lift position (Z-direction position) of the head 52. By configuring the controller 9 to perform the Z-axis drive so as to cancel the influence of the cogging force, gravity, spring 56 force, frictional force, etc. of the Z-axis drive motor 53 as the head 52 moves up and down. Since the driving force of the motor 53 can be varied according to the lift position of the head 52, the load control of the head 52 can be performed with high accuracy. In particular, in the control for applying a low load to the head 52, as shown in FIG. 11, the effects of the cogging force of the Z-axis drive motor 53, gravity, the force of the spring 56, and the frictional force on the load are relatively large. The surface mounting apparatus 100 that can accurately control the load of the head 52 is effective.

  In the first embodiment, the controller 9 controls the current supplied to the Z-axis drive motor 53 according to the amount of loss of the driving force of the Z-axis drive motor 53 according to the lift position (Z-direction position) of the head 52. By variably controlling the upper limit value (second current limit value), the load control of the head 52 is performed, so that the cogging force of the Z-axis drive motor 53 that varies depending on the lift position of the head 52 and the spring 56 The upper limit value of the current supplied to the Z-axis drive motor 53 so that the actual drive force of the Z-axis drive motor 53 obtained by subtracting the loss amount according to the loss amount of the drive force due to force or the like becomes a predetermined magnitude ( Since the second current limit value) can be variably controlled, the load control of the head 52 can be performed with higher accuracy.

  Further, in the first embodiment, the controller 9 is configured to drive the Z axis according to the lift position of the head 52 so that the load on the head 52 has a predetermined magnitude regardless of the lift position (Z direction position) of the head 52. The load control of the head 52 is performed by variably controlling the upper limit value (second current limit value) of the current supplied to the Z-axis drive motor 53 according to the loss amount of the driving force of the motor 53. Therefore, the load of the head 52 can be easily controlled so as to have a predetermined magnitude regardless of the elevation position of the head 52. Therefore, the component 4a can be used for a plurality of types of components 4a having different heights. Such a load can be easily set to a predetermined magnitude.

  In the first embodiment, the controller 9 measures the loss amount of the driving force of the Z-axis drive motor 53 according to the lift position (Z direction position) of the head 52 in advance, and based on the measurement result of the loss amount. By configuring so that the load control of the head 52 is performed, the load control of the head 52 can be performed more accurately based on the measurement result obtained in advance.

  In the first embodiment, the controller 9 is configured to perform load control of the head 52 based on the measurement result of the loss current stored in the storage unit 92, thereby performing measurement every time the head 52 is moved up and down. The load control of the head 52 can be accurately performed based on the measurement result of the loss current stored in the storage unit 92.

  In the first embodiment, the controller 9 measures the loss amount of the driving force of the Z-axis drive motor 53 according to the lift position (Z direction position) of the head 52 while the surface mounting apparatus 100 is in operation. When the difference between the measurement result during operation of the mounting apparatus 100 and the measurement result stored in the storage unit 92 is larger than a predetermined amount, the user is notified based on the measurement result, and based on the user's operation By configuring the control to update the measurement result, even when the amount of loss changes even at the same position, for example, when the temperature changes during operation of the surface mounting apparatus 100, the head is adjusted in accordance with the change in the amount of loss. The load control 52 can be accurately performed.

  In the first embodiment, the controller 9 measures the loss amount of the driving force of the Z-axis drive motor 53 according to the lift position (Z direction position) of the head 52 while moving the head 52 at a constant speed. Since the head 52 moves at a constant speed, it is not necessary to consider the force caused by the acceleration of the head 52. Thereby, the loss amount of the driving force of the Z-axis drive motor 53 according to the raising / lowering position of the head 52 can be easily measured. Further, since the amount of loss can be measured simply by moving the head 52 at a constant speed, it is not necessary to use a measurement-dedicated jig. Further, the loss amount can be easily measured during the operation of the surface mounting apparatus 100.

(Second Embodiment)
Next, with reference to FIG. 12, the structure of the surface mounting apparatus 100 (refer FIG. 1) by 2nd Embodiment of this invention is demonstrated. In the second embodiment, unlike the first embodiment in which the lowering speed of the head 52 is not switched, a configuration for switching the lowering speed of the head 52 will be described. The basic configuration of the surface mounting apparatus 100 according to the second embodiment is the same as that of the first embodiment. Therefore, in the following description, only differences from the first embodiment will be described in detail.

  Here, in the second embodiment, the controller 9 is configured to switch the descending speed while the head 52 is descending. Specifically, the controller 9 switches the upper limit value of the current in the positive direction from the first current limit value to the second current limit value in step S6 of FIG. 12, and then detects the position by the position reading unit 96 in step S19. Based on the position, it is determined whether or not the head 52 has reached a predetermined speed switching position. If it is determined that it has not reached, the controller 9 continues the downward PTP movement of the head 52 in step S21 and returns to step S19. When the head 52 reaches the speed switching position, the controller 9 switches the lowering speed of the head 16 to a predetermined speed lower than the previous lowering speed in step S20, and proceeds to step S7.

  In addition, the other structure of 2nd Embodiment is the same as that of the said 1st Embodiment.

  As described above, also in the configuration of the second embodiment, similarly to the first embodiment, the controller 9 sets the upper limit value (second current limit value) of the current supplied to the Z-axis drive motor 53 of the head 52. The load control of the head 52 can be performed with high accuracy by performing the load control of the head 52 by variably controlling according to the lift position (Z direction position).

  Furthermore, in the second embodiment, as described above, since the lowering speed is once reduced before the head 52 reaches the lower end position, a large impact force is generated when the head 52 (nozzle 52a) contacts the part 4a. It can suppress acting on 4a. Thereby, the damage of the component 4a by the collision with the head 52 and the component 4a can be suppressed.

  The remaining effects of the second embodiment are similar to those of the aforementioned first embodiment.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiments but by the scope of claims for patent, and further includes all modifications within the meaning and scope equivalent to the scope of claims for patent.

  For example, in the first and second embodiments, the example in which the present invention is applied to the surface mounting apparatus is shown, but the present invention is not limited to this. The present invention may be applied to devices other than surface mount devices as long as the load control of the head driven by a motor is performed. For example, the present invention may be applied to a component supply device or a dispenser such as an adhesive or solder.

  Further, in the first and second embodiments, the controller as the control unit measures the loss amount of the driving force of the Z-axis drive motor as the motor according to the lift position of the head only once, and the measurement result is the head. Although the example used for the load control is shown, the present invention is not limited to this. In the present invention, even if the control unit measures the loss amount of the driving force of the motor according to the lift position of the head a plurality of times to obtain the average value, and performs the load control of the head using the average value of the loss amount. Good. In this way, by taking the average value obtained by measuring the loss amount a plurality of times, the loss amount can be calculated more accurately, so that the head load control can be performed with higher accuracy.

  In the first and second embodiments, the example in which the head descending drive, the load control, and the ascending drive are performed by a series of operations has been described. However, the present invention is not limited to this. In the present invention, the head load control may be performed independently of the downward driving and the upward driving.

  In the first and second embodiments, the example in which the storage unit is included in the controller as the control unit has been described. However, the present invention is not limited to this. In the present invention, the storage unit may be provided separately from the control unit.

In the first and second embodiments, the difference between the measurement result of the loss amount of the Z-axis drive motor as the motor during operation of the surface mount device and the measurement result stored in the storage unit is a predetermined difference. In the case where the amount is larger than (amount), the user is notified based on the measurement result, and the example of the configuration for performing the control to update the measurement result based on the user's operation is shown, but the present invention is not limited to this. In the present invention, the measurement result during operation of the surface mounting apparatus, when the difference between the measurement results stored in the storage unit is greater than a predetermined amount, the notification based on the control and measurement result to update the measurement result only it needs to be configured to perform the control performed by the user.

  Further, in the first and second embodiments, for convenience of explanation, the processing operation of the controller (control unit) has been described using a flow-driven flowchart in which processing is performed in order along the processing flow. It is not limited to this. In the present invention, the processing operation of the control unit may be performed by event-driven (event-driven) processing that executes processing in units of events. In this case, it may be performed by a complete event drive type or a combination of event drive and flow drive.

4a Parts 9 Controller (Control part)
52 Head 53 Z-axis drive motor (motor)
92 Storage Unit 100 Surface Mount Device

Claims (7)

A component mounting head;
A motor for driving the head up and down;
A control unit for controlling a load applied to the component by the head by controlling a motor current ;
A storage unit that stores a measurement result of a loss amount of the driving force of the motor according to the lift position of the head ;
The control unit measures in advance a loss amount of the driving force of the motor according to the lift position of the head and stores it in the storage unit, and controls the load based on the measurement result stored in the storage unit. By variably controlling the set value of the motor current for the head in accordance with the lift position of the head, the load applied to the component is applied to the lift position of the head while the head applies a load to the component. The load control of the head is performed so as to be substantially constant regardless of the above, and the measurement result of measuring the loss amount of the driving force of the motor according to the lift position of the head during operation is stored in the storage unit. A surface mounting apparatus configured to perform control to update the measurement result when a difference from the measurement result is larger than a predetermined amount . The control unit variably controls the set value of the motor current according to the amount of loss of the driving force of the motor according to the lift position of the head, so that the head applies a load to the component. The surface mount device according to claim 1 , wherein the load control of the head is performed such that a load applied to the component is substantially constant regardless of a lift position of the head. While the head is applying a load to the component , the control unit is configured so that the load on the head has a predetermined magnitude and a substantially constant magnitude regardless of the elevation position of the head. depending on the amount of loss of the driving force of said motor in response to the vertical position, the set value of the motor current by variably controlling, is configured to perform a load control of the head, to claim 1 or 2 The surface mount apparatus described . The control unit measures a loss amount of the driving force of the motor according to the lift position of the head during operation of the surface mounting apparatus, the measurement result during operation of the surface mounting apparatus, and the storage unit the difference between the measurement result stored is configured is greater than a predetermined amount, performing control to notify based on the control and the measurement result to update the measurement results to the user, The surface-mount apparatus of any one of Claims 1-3 . Wherein the control unit is configured to measure the loss of the driving force of the motor in accordance with the vertical position of the head while moving the head at a constant speed, any of the preceding claims 1 The surface mounting apparatus as described in a term. The control unit obtains an average value by measuring a loss amount of the driving force of the motor according to the lift position of the head a plurality of times, and performs load control of the head based on the average value of the loss amount. is configured as a surface mounting apparatus according to any one of claims 1 to 5. Measuring the amount of loss of the driving force of the motor according to the elevation position of the head during operation of the surface mount device in advance and storing it in the storage unit;
The head applies a load to the component by variably controlling the set value of the motor current for controlling the load of the head based on the measurement result stored in the storage unit according to the lift position of the head. during the the steps of the load applied to the component performs load control of the head so as to be approximately constant regardless of the vertical position of the head,
A difference between the measurement result obtained by measuring the loss amount of the driving force of the motor according to the lift position of the head during the operation of the surface mount device and the measurement result stored in the storage unit is a predetermined amount. A head drive control method comprising: updating the measurement result when the measurement result is greater than .

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