Component Mounting Machine

Abstract

To provide a component mounting machine capable of suppressing damage to a component during a component holding operation of a mounting head that holds the component accommodated in a component storage portion on a tray, and capable of suppressing a decrease in efficiency of the component holding operation.SOLUTION: A control unit 4 executes a movement process S1 of moving a mounting head 251 downward until a holding surface 251A of the mounting head 251 comes into contact with a component in a component storage portion 61 on a tray 6 when controlling the component holding operation of the mounting head 251 using the thrust limit start height D5, and a detection process S2 of detecting the component contact height D5T at which the holding surface 251A contacts the component. When the movement process S1 is performed in response to a specific component storage portion 61 that satisfies an update condition D6, the control unit 4 calculates a predicted component contact height D5T1 on the basis of the component contact height D5T corresponding to the already held component P1, and updates the thrust limit start height D5 on the basis of the predicted component contact height D5T1.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to a component mounter that holds components accommodated in component accommodation sections on a tray with a mounting head and mounts them onto a board. [Background technology]

[0002] A known component mounter for mounting components onto a substrate to produce a component-mounted substrate is equipped with a component supply device that supplies components to a mounting head by moving a pallet on which a tray having a plurality of component storage compartments for storing components is placed. In this type of component mounter, the mounting head performs a component holding operation in which the mounting head is positioned above the component storage compartments on the tray and moves downward until the holding surface comes into contact with the component, thereby holding the component in the component storage compartment, and then performs a component mounting operation in which the held component is mounted onto the substrate.

[0003] When a tray is deformed, such as warped or tilted, the component contact height, which indicates the height position at which the mounting head's holding surface contacts a component held in a component holding section on the tray, may differ for each component holding section. Patent Document 1 discloses a technology for estimating such tray deformation and controlling the component holding operation of the mounting head. In the technology disclosed in Patent Document 1, when the mounting head (suction nozzle) is unable to hold a component on the tray, a measuring head measures the height of the top surface of the tray or the top surface height (component contact height) of the component in the component holding section to estimate the tray deformation, and corrects the top surface height of the component in the component holding section on the tray based on the estimation result. The component holding operation of the mounting head is then controlled based on the corrected component top surface height. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-249704 Summary of the Invention [Problem to be solved by the invention]

[0005] However, if the impact force applied to the component when the mounting head moves downward and contacts the component during the component holding operation is too large, the component may be damaged. Therefore, in controlling the component holding operation of the mounting head, the mounting head's descent speed is slowed down during the downward movement of the mounting head to limit the thrust of the mounting head. In this case, a thrust limit start height, which indicates the start point at which the thrust of the mounting head is limited, is set in advance based on the component contact height. Setting this thrust limit start height is not disclosed in Patent Document 1. Setting the thrust limit start height is important when controlling the component holding operation of the mounting head. That is, if the thrust limit start height is too close to the component contact height in the vertical direction of the mounting head movement, the thrust limit of the mounting head will not function effectively during the component holding operation of the mounting head, resulting in component damage. On the other hand, if the thrust limit start height is too far from the component contact height, the time required for the descent speed to be decelerated during the component holding operation of the mounting head will be too long, reducing the efficiency of the component holding operation.

[0006] An object of the present invention is to provide a component mounting machine that can prevent damage to components during the component holding operation of a mounting head that holds components accommodated in a component storage section on a tray, and that can prevent a decrease in the efficiency of the component holding operation. [Means for solving the problem]

[0007] a component supply device that supplies components by moving a pallet on which a tray having a plurality of component storage sections for storing components is placed; a mount head that has a holding surface for holding components and that mounts the components held on the holding surface onto a board, the mount head being movable in a vertical direction perpendicular to the holding surface, and that, with the holding surface positioned at a reference position above the component storage sections, performs a component holding operation for each of the component storage sections by moving downward until the holding surface comes into contact with a component; a memory unit that stores a thrust limit start height that indicates, as a height from the pallet, a start position at which a limit is placed on a thrust force when the mount head moves downward in the component holding operation, and an update condition that indicates a condition for updating the thrust limit start height by the number of components already held by the mount head; and a control unit that determines whether the update condition is met for each of the component storage sections, and controls the component holding operation of the mount head using the thrust limit start height. The control unit performs a movement process in which the control unit moves the mounting head downward while the mounting head is positioned at the reference position, starts limiting the thrust of the mounting head when the holding surface reaches the thrust limit start height, and maintains the thrust limit state until the holding surface contacts a component in the component storage unit, and a detection process in which the control unit detects a component contact height, which indicates a position above the pallet where the holding surface contacts a component in the component storage unit, based on a change in thrust of the mounting head from the thrust limit state. When the control unit performs the movement process corresponding to a specific component storage unit that satisfies the update condition, the control unit calculates a predicted component contact height that assumes contact of the holding surface with a component in the specific component storage unit based on the component contact height detected in the detection process corresponding to the already-held component, and updates the thrust limit start height based on the predicted component contact height.

[0008] According to this component mounter, when controlling the component holding operation of a mount head that holds a component housed in a component storage unit on a tray using the thrust limit start height, the control unit performs a movement process that moves the mount head downward until the holding surface of the mount head contacts a component in the component storage unit, and a detection process that detects a component contact height indicating the height position at which the holding surface contacts the component. In the movement process, the control unit slows down the descent speed of the mount head when the holding surface reaches the thrust limit start height, thereby starting to limit the thrust of the mount head, and maintains the thrust limit state until the holding surface contacts a component in the component storage unit. This prevents the impact force applied to the component when the mount head moves downward and contacts the component during the component holding operation from increasing, thereby preventing component damage. Furthermore, in the detection process, the control unit detects the component contact height when the holding surface of the mount head contacts a component in the component storage unit based on a change in thrust from the thrust limit state of the mount head. This allows the component contact height to be detected based on the change in thrust of the mount head, without using a dedicated measuring head for height measurement as in conventional technology.

[0009] Furthermore, when performing the movement process and detection process for each component storage unit on the tray, the control unit determines whether an update condition, indicated by the number of currently held components, is met to update the thrust limit start height. When the movement process is performed for a specific component storage unit that satisfies the update condition, the movement process and detection process for the number of currently held components indicated by the update condition have already been performed. When performing the movement process for a specific component storage unit that satisfies the update condition, the control unit calculates a predicted component contact height, assuming contact of the mounting head's holding surface with the components in the specific component storage unit, based on the component contact height detected in the detection process for the currently held components. Because the predicted component contact height is calculated based on the actual component contact height for the currently held components, it provides a highly accurate predicted value for the component contact height for the specific component storage unit.

[0010] The control unit then updates the thrust limit start height corresponding to the specific component storage unit based on the predicted component contact height. This allows the thrust limit start height corresponding to the specific component storage unit to be set to an appropriate value based on the predicted component contact height. Therefore, when the mounting head corresponding to the specific component storage unit moves downward during a component holding operation, the thrust limit of the mounting head effectively functions from the updated thrust limit start height, preventing component damage. Furthermore, the deceleration time of the mounting head's descent speed when the thrust limit is set is appropriate, preventing a decrease in the efficiency of the component holding operation.

[0011] In the component mounter, the control unit may calculate the predicted component contact height by a least squares method based on a plurality of component contact heights corresponding to a plurality of the already held components.

[0012] In this aspect, the control unit can accurately calculate the predicted component contact height corresponding to a specific component receiving section that satisfies the update condition by the least squares method.

[0013] In the component mounter described above, the control unit may set a value obtained by adding a certain margin to the predicted component contact height as the updated thrust force limitation start height.

[0014] In this aspect, the control unit can set a value obtained by adding a certain margin to the predicted component contact height as the thrust limit start height, corresponding to a specific component receiving unit that satisfies the update condition.

[0015] In the above-mentioned component mounting machine, the control unit may extract a maximum component contact height that indicates the maximum value from among the multiple component contact heights corresponding to the multiple already-held components, calculate a margin based on the maximum component contact height, and set a value obtained by adding the calculated margin to the predicted component contact height as the updated thrust limit start height.

[0016] In this embodiment, the control unit can calculate a margin based on the maximum component contact height among the multiple component contact heights corresponding to the multiple already-held components, and can set the value obtained by adding the calculated margin to the predicted component contact height as the thrust limit start height for a specific component storage unit that satisfies the update condition.

[0017] In the component mounter, the control unit may update the thrust limit start height each time the movement process is performed in response to the specific component accommodation unit that satisfies the update condition.

[0018] In this embodiment, the control unit updates the thrust limit start height for each specific component housing unit that satisfies the update condition, thereby setting an appropriate thrust limit start height for each specific component housing unit based on the predicted component contact height.

[0019] In the component mounter, the component storage units are arranged in a matrix on the tray in a first direction and a second direction that are orthogonal to each other, and the update condition may be set based on the number of previously held components corresponding to each row of the component storage units arranged along the first direction in the component storage units arranged in the matrix.

[0020] Furthermore, in the above-described component mounter, when the control unit, in controlling the component holding operation of the mounting head, performs the movement process and the detection process corresponding to the component storage units in a first row arranged along the first direction, and then performs the movement process and the detection process corresponding to the component storage units in a second row adjacent to the first row in the second direction, for the component storage units in the second row that do not satisfy the update condition, the control unit sets the thrust limit start height based on the component contact height detected in the detection process corresponding to the component storage units in the first row adjacent in the second direction, and performs the movement process, and detects the component contact height corresponding to the already-held component in the subsequent detection process, and for the component storage units in the second row that satisfy the update condition, the control unit calculates the predicted component contact height based on the component contact height corresponding to the already-held component, and performs the movement process using the thrust limit start height after updating based on the predicted component contact height.

[0021] In this aspect, the update condition indicating the condition for updating the thrust limit start height is set by the number of already-held components corresponding to each row of the component storage units arranged along the first direction in a matrix of the component storage units on the tray. The control unit determines whether the update condition is met for each row of the component storage units arranged along the first direction for the component storage units arranged in the matrix of the tray, sets the thrust limit start height, and performs movement processing and detection processing for each component storage unit.

[0022] Assume that, after performing movement and detection processes for component storage units in a first row arranged in a first direction, movement and detection processes for component storage units in a second row adjacent to the first row in a second direction are performed. In this case, for component storage units in the second row that do not satisfy the update condition, the control unit can set a thrust limit start height based on the component contact height detected in the detection process for the component storage units in the first row adjacent to the second direction. The control unit then performs movement processing using the set thrust limit start height, and then detects the component contact height corresponding to the already-held component in the subsequent detection process. Meanwhile, for component storage units in the second row that satisfy the update condition, the control unit calculates a predicted component contact height based on the component contact height corresponding to the already-held component in the second row, and performs movement processing using the updated thrust limit start height based on the predicted component contact height.

[0023] In the component mounter, the component storage units are arranged in a matrix on the tray in a first direction and a second direction that are orthogonal to each other, and the update condition may be set based on the number of the already-held components corresponding to the component storage units arranged in the matrix.

[0024] Furthermore, in the component mounting machine described above, for a component storage unit among the plurality of component storage units that does not satisfy the update conditions, the control unit performs the movement process using the thrust limit start height stored in the memory unit as is, and in the subsequent detection process detects the component contact height corresponding to the already held component, and for a component storage unit among the plurality of component storage units that satisfies the update conditions, calculates the predicted component contact height based on the component contact height corresponding to the already held component, and performs the movement process using the thrust limit start height after updating based on the predicted component contact height.

[0025] In this embodiment, the update condition, which indicates the condition for updating the thrust limit start height, is set based on the number of currently held components corresponding to the multiple component storage units arranged in a matrix on the tray. In this case, for the multiple component storage units that do not satisfy the update condition, the control unit performs a movement process using the thrust limit start height stored in the memory unit as is, and then detects the component contact height corresponding to the currently held component in the subsequent detection process. On the other hand, for the multiple component storage units that satisfy the update condition, the control unit calculates a predicted component contact height based on the component contact height corresponding to the currently held component, and performs a movement process using the updated thrust limit start height based on the predicted component contact height.

[0026] In the component mounter, the component storage units are arranged in a matrix on the tray in a first direction and a second direction perpendicular to each other, and the update condition may be set by a first number of already-held components indicating the number of already-held components corresponding to the component storage units in each row arranged along the first direction, and a second number of already-held components indicating the number of already-held components corresponding to the component storage units in each column arranged along the second direction, in the component storage units arranged in a matrix.

[0027] Furthermore, in the component mounting machine described above, for a component storage unit among the plurality of component storage units that does not satisfy the update conditions, the control unit performs the movement process using the thrust limit start height stored in the memory unit as is, and in the subsequent detection process detects the component contact height corresponding to the already held component, and for a component storage unit among the plurality of component storage units that satisfies the update conditions, calculates the predicted component contact height based on the component contact height corresponding to the already held component, and performs the movement process using the thrust limit start height after updating based on the predicted component contact height.

[0028] In this aspect, the update condition indicating the condition for updating the thrust limit start height is set by a first number of held components indicating the number of held components corresponding to each row of component storage sections arranged along the first direction in a matrix of multiple component storage sections on the tray, and a second number of held components indicating the number of held components corresponding to each column of component storage sections arranged along the second direction. In this case, for each of the multiple component storage sections that does not satisfy the update condition, the control unit performs a movement process using the thrust limit start height stored in the memory unit as is, and then detects the component contact height corresponding to the currently held component in a subsequent detection process. On the other hand, for each of the multiple component storage sections that satisfies the update condition, the control unit calculates a predicted component contact height based on the component contact height corresponding to the currently held component, and performs a movement process using the updated thrust limit start height based on the predicted component contact height.

[0029] In the component mounter, the component storage units are arranged in a matrix on the tray in a first direction and a second direction that are orthogonal to each other, and the update condition may be set based on the number of already-held components within a predetermined range around a component storage unit that is a control target of the mounting head by the control unit, for the component storage units arranged in a matrix.

[0030] Furthermore, in the component mounting machine described above, for a component storage unit among the plurality of component storage units that does not satisfy the update conditions, the control unit performs the movement process using the thrust limit start height stored in the memory unit as is, and in the subsequent detection process detects the component contact height corresponding to the already held component, and for a component storage unit among the plurality of component storage units that satisfies the update conditions, calculates the predicted component contact height based on the component contact height corresponding to the already held component, and performs the movement process using the thrust limit start height after updating based on the predicted component contact height.

[0031] In this aspect, the update condition, which indicates the condition for updating the thrust limit start height, is set based on the number of already-held components within a predetermined range around the component storage unit targeted for control of the mounting head by the control unit, among the component storage units arranged in a matrix on the tray. In this case, for the component storage units that do not satisfy the update condition, the control unit performs a movement process using the thrust limit start height stored in the memory unit as is, and then detects the component contact height corresponding to the already-held component in a subsequent detection process. On the other hand, for the component storage units that satisfy the update condition, the control unit calculates a predicted component contact height based on the component contact height corresponding to the already-held component, and performs a movement process using the updated thrust limit start height based on the predicted component contact height. [Effects of the Invention]

[0032] As described above, according to the present invention, it is possible to provide a component mounter that can prevent damage to components during the component holding operation of the mounting head that holds components accommodated in the component storage section on the tray, and that can prevent a decrease in the efficiency of the component holding operation. [Brief explanation of the drawings]

[0033] [Figure 1] 1 is a block diagram of a component mounter according to an embodiment of the present invention. [Figure 2] FIG. 2 is a plan view showing the configuration of a mounter body of the component mounter. [Figure 3] FIG. 2 is a diagram illustrating a schematic configuration of a component supply device provided in the mounting machine main body. [Figure 4] FIG. 2 is a plan view showing a pallet used in the component supply device. [Figure 5] FIG. 2 is an enlarged view showing a head unit provided in the mounting machine main body. [Figure 6] 10A and 10B are diagrams illustrating processing when an update condition is not satisfied when a control unit of a component mounter controls a component holding operation of a mounting head. [Figure 7]10A and 10B are diagrams illustrating processing when an update condition is satisfied when a control unit of a component mounter controls a component holding operation of a mounting head. [Figure 8] 10A and 10B are diagrams illustrating the setting of a thrust limit start height used when the control unit performs movement processing. [Figure 9] 10A and 10B are diagrams illustrating a first example of when a control unit sets a thrust limit start height. [Figure 10] 10A and 10B are diagrams illustrating a first example of a case where a control unit sets a thrust limit start height. [Figure 11] 10A and 10B are diagrams illustrating a second example of when the control unit sets the thrust limit start height. [Figure 12] 10A and 10B are diagrams illustrating a third example of when the control unit sets the thrust limit start height. [Figure 13] 10A and 10B are diagrams illustrating a fourth example of a case where the control unit sets a thrust limit start height. DETAILED DESCRIPTION OF THE INVENTION

[0034] Hereinafter, a component mounter according to an embodiment of the present invention will be described with reference to the drawings.

[0035] [Overall configuration of component mounter] The component mounter 1 shown in the block diagram of FIG. 1 is a device that produces electronic circuit boards in which electronic components (hereinafter referred to as "components") are mounted on printed circuit boards (hereinafter referred to as "boards"). The component mounter 1 comprises a mounter main body 2, a memory unit 3, and a control unit 4. The mounter main body 2 constitutes a structural portion that performs a component holding operation to hold components and a component mounting operation to mount the components on the board. The memory unit 3 stores management data D1 that is referenced when the mounter main body 2 performs the component holding operation and the component mounting operation. The control unit 4 reads out the management data D1 stored in the memory unit 3 and controls the component holding operation and the component mounting operation of the mounter main body 2 based on the management data D1.

[0036] First, the mounting machine main body 2 will be described with reference to Fig. 1 as well as Figs. 2 to 5. Note that directional relationships will be described below using XY Cartesian coordinates that are orthogonal to each other on a horizontal plane. Also, one side in the X-axis direction will be referred to as the "+X side," and the other side opposite to the one side in the X-axis direction will be referred to as the "-X side." Similarly, one side in the Y-axis direction will be referred to as the "+Y side," and the other side opposite to the one side in the Y-axis direction will be referred to as the "-Y side."

[0037] A solder paste pattern is printed on the substrate PP before components are mounted by the mounting machine main body 2. In other words, the mounting machine main body 2 mounts components onto the substrate PP on which a solder paste pattern has been printed by a pattern forming device. The mounting machine main body 2 includes a main body frame 21, a conveyor 23, a component supply device 24, a head unit 25, and a substrate support unit 28.

[0038] The main body frame 21 is a structure on which the various components of the mounting machine main body 2 are arranged, and has a generally rectangular shape in a plan view seen from a direction (vertical direction) perpendicular to both the X-axis direction and the Y-axis direction. The conveyor 23 extends in the X-axis direction and is arranged on the main body frame 21. The conveyor 23 transports the board PP in the X-axis direction. The board PP transported on the conveyor 23 is positioned by the board support unit 28 at a predetermined work position (a component mounting position where components are mounted on the board PP). The board support unit 28 positions the board PP by supporting the board PP with push-up pins.

[0039] The component supply devices 24 are arranged across the conveyor 23 in the regions on the +Y side and the -Y side in the Y-axis direction of the main body frame 21. As shown in Figs. 3 and 4, the component supply devices 24 are devices that supply components P by moving, in the Y-axis direction, a pallet 5 on which a tray 6 having a plurality of component storage sections 61 for storing components P is placed. Note that the mounting machine main body 2 may also be equipped with, as a feeder that supplies components P, a tape feeder that supplies components using tape as a carrier, or a stick feeder that supplies components stored in a cylindrical stick while pushing the components out of the stick.

[0040] The component supply device 24 includes a device main body 241 , a pallet storage section 242 , a pallet placement table 243 , a storage section moving mechanism 244 , a pallet moving mechanism 245 , and a table moving mechanism 246 .

[0041] The device main body 241 is a housing having a storage space capable of accommodating the pallet storage unit 242. The pallet storage unit 242 is a structure that stores multiple pallets 5 lined up in the Z-axis direction, which is perpendicular to both the X-axis direction and the Y-axis direction. The pallet storage unit 242 is housed within the device main body 241 so as to be movable in the Z-axis direction. The pallet storage unit 242 includes a magazine 2421. The magazine 2421 is a box-shaped structure with both ends open in the Y-axis direction. On both sides of the magazine 2421 in the X-axis direction, multiple support members 242A are arranged side by side in the Z-axis direction to support the pallets 5 so as to be movable in the Y-axis direction. As shown in FIG. 4 , a tray 6 having multiple component storage units 61 for storing components P is placed on the pallet 5 stored in the pallet storage unit 242. The tray 6 has a rectangular shape in a plan view. The multiple component storage units 61 are arranged in a matrix on the tray 6 in the X-axis direction (first direction) and the Y-axis direction (second direction), which are perpendicular to each other.

[0042] The storage unit moving mechanism 244 is a mechanism that moves the pallet storage unit 242 in the Z-axis direction within the device main body 241. The storage unit moving mechanism 244 includes a ball screw shaft 2441, a ball nut 2442, and a drive motor 2443. The ball screw shaft 2441 is a ball screw shaft that extends in the Z-axis direction within the device main body 241. The ball nut 2442 is threadedly engaged with the ball screw shaft 2441. The drive motor 2443 has its output shaft connected to the ball screw shaft 2441. The pallet storage unit 242 is attached to the ball nut 2442. In the storage unit moving mechanism 244, when the drive motor 2443 is driven to rotate, the ball nut 2442 advances and retreats along the ball screw shaft 2441. As a result, the pallet storage unit 242 attached to the ball nut 2442 moves in the Z-axis direction.

[0043] The pallet placing table 243 is supported movably in the Y-axis direction by a table support part 2411 that protrudes outward from a side part facing the Y-axis direction of the device main body 241. The pallet placing table 243 has a rectangular shape in a plan view on which a pallet 5 can be placed, and serves as a supply area for the pallet 5 to the head unit 25.

[0044] The pallet moving mechanism 245 is disposed on the pallet placing table 243. The pallet moving mechanism 245 is a mechanism for moving the pallet 5 between the pallet storage unit 242 and the pallet placing table 243. The table moving mechanism 246 is a mechanism for moving the pallet placing table 243 in the Y-axis direction. The table moving mechanism 246 moves the pallet placing table 243 between a position where the pallet 5 is moved between the pallet placing table 243 and the pallet storage unit 242, and a position where the pallet 5 is supplied to the head unit 25.

[0045] The head unit 25 is held by a moving frame 27. A fixed rail 261 extending in the Y-axis direction and a ball screw shaft 262 rotated by a Y-axis servo motor 263 are arranged on the main body frame 21. The moving frame 27 is placed on the fixed rail 261, and a nut portion 271 provided on the moving frame 27 is threadedly engaged with the ball screw shaft 262. The moving frame 27 is also provided with a guide member 272 extending in the X-axis direction and a ball screw shaft 273 driven by an X-axis servo motor 274. The head unit 25 is movably held by the guide member 272, and a nut portion provided on the head unit 25 is threadedly engaged with the ball screw shaft 273. The moving frame 27 moves in the Y-axis direction when the Y-axis servo motor 263 is operated, and the head unit 25 moves in the X-axis direction relative to the moving frame 27 when the X-axis servo motor 274 is operated. That is, head unit 25 is movable in the Y-axis direction in conjunction with the movement of movable frame 27, and is also movable in the X-axis direction along movable frame 27. Head unit 25 is movable between pallet placement table 243, which serves as a supply location for pallets 5 in component supply device 24, and a predetermined working position for board PP transported by conveyor 23.

[0046] As shown in FIG. 5, the head unit 25 includes a plurality of mounting heads 251. Each mounting head 251 performs a component-holding operation to hold a component P on a tray 6 on a pallet 5 supplied to the pallet placement table 243 by the component supply device 24, and also performs a component-mounting operation to mount (mount) the held component P on a board PP. A holding nozzle 2511 is attached to the tip (lower end) of each mounting head 251. The holding nozzle 2511 is a holder having a holding surface 251A that suction-holds a component P on a tray 6 on the pallet 5. The holding nozzle 2511 can be connected to a negative pressure generator, a positive pressure generator, or the atmosphere via an electric switching valve. That is, supplying negative pressure to the holding nozzle 2511 enables the holding nozzle 2511 to suction-hold a component, and then supplying positive pressure releases the suction-holding of the component.

[0047] The mounting head 251 is movable in the Z-axis direction (up and down direction) perpendicular to the holding surface 251A relative to the frame of the head unit 25, and is also rotatable around a head axis extending in the Z-axis direction. The mounting head 251, while positioned at a holding reference position where the holding surface 251A is positioned above the component storage sections 61 on the tray 6, moves downward until the holding surface 251A contacts the component P, thereby performing a component holding operation for each of the component storage sections 61. After holding the component P, the mounting head 251 moves upward toward the holding reference position. Furthermore, while positioned at a mounting reference position where the holding surface 251A is positioned above the mounting position on the substrate PP, the mounting head 251 moves downward toward the substrate PP, thereby performing a component mounting operation for mounting the component P at the mounting position on the substrate PP. After mounting the component, the mounting head 251 moves upward toward the mounting reference position.

[0048] 2, a first imaging unit 29A is installed on the main body frame 21 between the component supply device 24 and the conveyor 23. The first imaging unit 29A is an imaging camera equipped with an imaging element such as a CMOS (Complementary Metal-Oxide-Semiconductor) or a CCD (Charged-Coupled Device). While the head unit 25 is moving from the component supply device 24 toward the work position of the board PP, the first imaging unit 29A captures an image of the component P held by the holding nozzle 2511 of the mounting head 251 from below to obtain a component recognition image. In the component mounter 1, the posture of the component P held on the holding surface 251A of the mounting head 251 is determined based on the component recognition image obtained by the first imaging unit 29A.

[0049] A second imaging unit 29B is also attached to the head unit 25. The second imaging unit 29B is an imaging camera equipped with an imaging element such as a CMOS or CCD. The second imaging unit 29B captures an image of marks and the like affixed to the top surface of the board PP transported by the conveyor 23 from above, and acquires a board recognition image for recognizing the board PP. In the component mounter 1, the amount of positional deviation of the board PP from the origin coordinates is detected based on the board recognition image acquired by the second imaging unit 29B.

[0050] 1, the storage unit 3 stores management data D1. The management data D1 is data that is referenced when the control unit 4 controls the mounting head 251 of the head unit 25, and includes component retention data D2 and component mounting data D7.

[0051] The component holding data D2 is data that the control unit 4 refers to when controlling the component holding operation of the mounting head 251. The component holding data D2 includes a component holding order D3, a component storage section position D4, a thrust limit start height D5, and an update condition D6. The component holding order D3 is information that indicates the order in which the mounting head 251 holds the components P in each component storage section 61 on the tray 6. The component storage section position D4 is information that indicates the coordinates of the position of the component storage section 61 on the tray 6. The component storage section position D4 includes, for example, a coordinate X that indicates the position of the component storage section 61 on the tray 6 in the X-axis direction and a coordinate Y that indicates the position of the component storage section 61 on the tray 6 in the Y-axis direction.

[0052] The thrust limit start height D5 is information that indicates, as a height from the pallet 5, the start position at which a limit is placed on the thrust when the mounting head 251 moves downward during a component holding operation for holding a component P in each component storage section 61 on the tray 6 placed on the pallet 5. The update condition D6 is information that indicates the condition for updating the thrust limit start height D5 as the number of components already held by the mounting head 251.

[0053] The component mounting data D7 is data that is referenced when the control unit 4 controls the component mounting operation of the mounting head 251. The component mounting data D7 includes information such as a mounting position D8. The mounting position D8 is information indicating coordinates related to the mounting position of the component P set on the board PP. The mounting position D8 includes, for example, a coordinate X related to the mounting position of the component P on the board PP in the X-axis direction, and a coordinate Y related to the mounting position of the component P on the board PP in the Y-axis direction.

[0054] The control unit 4 is composed of a CPU (Central Processing Unit), a ROM (Read Only Memory) that stores a control program, a RAM (Random Access Memory) that is used as a work area for the CPU, etc. The control unit 4 controls the operation of each component, including the head unit 25 of the mounting machine main body 2, by the CPU executing the control program stored in the ROM and referencing the management data D1 stored in the storage unit 3.

[0055] The control unit 4 controls the conveyance operation of the conveyor 23 to transport the board PP, and also controls the component supply operation of the component supply device 24 by moving the pallet 5.

[0056] Furthermore, the control unit 4 controls the movement operation of the head unit 25 in the X-axis direction and the Y-axis direction, and the movement operation of the mounting head 251 in the Z-axis direction and the rotation operation, thereby controlling the component holding operation in which the mounting head 251 holds the component P on the tray 6, and the component mounting operation in which the mounting head 251 mounts the component P on the board PP. At this time, the control unit 4 refers to the management data D1 stored in the memory unit 3.

[0057] The control unit 4 identifies the position of the component storage unit 61 on the tray 6 that stores the component P to be held by the mounting head 251 based on the component storage unit position D4 in accordance with the order indicated by the component holding order D3 in the component holding data D2, and controls the movement operation of the head unit 25 so that the head unit 25 moves toward the position of the component storage unit 61. When the mounting head 251 is placed at a reference position above the component storage units 61 on the tray 6, the control unit 4 determines whether the update condition D6 is satisfied for each of the multiple component storage units 61 on the tray 6, and controls the component holding operation of the mounting head 251 using the thrust limit start height D5. Details of the control of the component holding operation by the control unit 4 will be described later.

[0058] When the component P is held on the holding surface 251A of the mounting head 251, the control unit 4 controls the movement operation of the head unit 25 so that the head unit 25 moves toward the mounting position on the substrate PP indicated by the mounting position D8 in the component mounting data D7. When the head unit 25 arrives directly above the mounting position on the substrate PP that corresponds to the component P held by the mounting head 251, the control unit 4 controls the component mounting operation of the mounting head 251 to mount the component P on the substrate PP.

[0059] [Controlling component holding operations by the mounting head] The control of the component holding operation of the mounting head 251 performed by the control unit 4 will be described with reference to FIGS.

[0060] During the component holding operation of holding a component P in a component storage section 61 on a tray 6 placed on a pallet 5, if the impact force applied to the component P when the mounting head 251 moves downward and comes into contact with the component P is too great, the component P may be damaged. For this reason, in controlling the component holding operation of the mounting head 251, the control unit 4 controls the mounting head 251 to limit the thrust of the mounting head 251 by slowing down the descent speed while the mounting head 251 is moving downward. In this case, a thrust limit start height D5 is set, which indicates the start position at which the thrust of the mounting head 251 is limited, and the set thrust limit start height D5 is stored in the memory unit 3.

[0061] The thrust limit start height D5 is set based on the component contact height D5T, which indicates the height from the pallet 5 at which the holding surface 251A of the mounting head 251 contacts a component P in the component storage section 61 on the tray 6. The thrust limit start height D5 is set to a value sufficiently larger than the component contact height D5T, taking into account possible deformation of the tray 6, such as warping or tilting. If the thrust limit start height D5 is too close to the component contact height D5T in the Z-axis direction in which the mounting head 251 moves during the component holding operation, the thrust limit of the mounting head 251 will not function effectively, resulting in damage to the component P. On the other hand, if the thrust limit start height D5 is too far from the component contact height D5T, the deceleration time for the descent speed of the mounting head 251 during the component holding operation will be too long, reducing the efficiency of the component holding operation. Therefore, the setting of the thrust limit start height D5 is important when controlling the component holding operation of the mounting head 251.

[0062] The control unit 4 controls the component holding operation of the mounting head 251 when the mounting head 251 is positioned at a reference position above the component storage unit 61 on the tray 6. When the mounting head 251 is positioned at the reference position, the holding surface 251A is positioned at a reference height D5S. When controlling the component holding operation of the mounting head 251 using the thrust limit start height D5, the control unit 4 performs a movement process S1 in which the mounting head 251 is moved downward until the holding surface 251A of the mounting head 251 contacts the component P in the component storage unit 61, and a detection process S2 in which a component contact height D5T indicating the height position at which the holding surface 251A contacts the component P is detected.

[0063] In the movement process S1, when the holding surface 251A reaches the thrust limit start height D5, the control unit 4 starts limiting the thrust of the mounting head 251 by slowing down the descent speed of the mounting head 251, and maintains this thrust limit state until the holding surface 251A comes into contact with a component P in the component storage unit 61. This prevents the impact force applied to the component P from increasing when the mounting head 251 moves downward during the component holding operation and comes into contact with the component P, thereby preventing damage to the component P. Furthermore, in the detection process S2, the control unit 4 detects the component contact height D5T when the holding surface 251A of the mounting head 251 comes into contact with the component P in the component storage unit 61 based on the change in thrust of the mounting head 251 from the thrust limit state. This makes it possible to detect the component contact height D5T based on the change in thrust of the mounting head 251, without using a measurement head dedicated to height measurement as in the prior art.

[0064] In addition, when the control unit 4 performs the movement process S1 and the detection process S2 corresponding to each component storage section 61 on the tray 6, it determines whether the condition for updating the thrust limit start height D5 is met, which is an update condition D6 indicated by the number of already held components P1.

[0065] 6, when the movement process S1 is performed for a component storage unit 61 that does not satisfy the update condition D6, the movement process S1 and the detection process S2 are not performed for the number of already-held components P1 indicated by the update condition D6. When the movement process S1 is performed for a component storage unit 61 that does not satisfy the update condition D6, the control unit 4 performs the movement process S1 using the thrust limit start height D5 stored in the memory unit 3 as is.

[0066] 7, when the movement process S1 is performed for a component storage unit 61 that satisfies the update condition D6, the movement process S1 and detection process S2 have already been performed for the number of previously held components P1 indicated by the update condition D6. When the movement process S1 is performed for a specific component storage unit 61 that satisfies the update condition D6, the control unit 4 calculates a predicted component contact height D5T1, which assumes contact of the holding surface 251A of the mounting head 251 with the component P in the specific component storage unit 61, based on the component contact height D5T detected in the detection process S2 for the previously held component P1. Because the predicted component contact height D5T1 is calculated based on the actual component contact height D5T for the previously held component P1, it is an accurate predicted value for the component contact height for the specific component storage unit 61 that satisfies the update condition D6.

[0067] The control unit 4 then updates the thrust limit start height D51 corresponding to the specific component storage unit 61 that satisfies the update condition D6 based on the predicted component contact height D5T1. This allows the thrust limit start height D51 corresponding to the specific component storage unit 61 to be set to an appropriate value based on the predicted component contact height D5T1. As a result, when the mounting head 251 corresponding to the specific component storage unit 61 moves downward during its component holding operation, the thrust limit of the mounting head 251 effectively functions from the position of the updated thrust limit start height D51, preventing damage to the component P. In addition, the deceleration time of the descent speed of the mounting head 251 in the thrust-limited state becomes appropriate, preventing a decrease in the efficiency of the component holding operation.

[0068] 8, when calculating the predicted component contact height D5T1 corresponding to a specific component storage unit 61 that satisfies the update condition D6, the control unit 4 calculates a least-squares line LSL using the least-squares method based on multiple component contact heights D5T corresponding to multiple already-held components P1. The control unit 4 then calculates the predicted component contact height D5T1 corresponding to the specific component storage unit 61 that satisfies the update condition D6 based on the least-squares line LSL. The control unit 4 can accurately calculate the predicted component contact height D5T1 corresponding to the specific component storage unit 61 that satisfies the update condition D6 using the least-squares method.

[0069] Furthermore, when the control unit 4 updates and sets the thrust-limit start height D51 based on the predicted component contact height D5T1 corresponding to a specific component storage section 61 that satisfies the update condition D6, it adds a certain margin MG to the predicted component contact height D5T1 to set the updated thrust-limit start height D51. Alternatively, the control unit 4 may extract the maximum component contact height that is the largest among the multiple component contact heights D5T corresponding to the multiple already-held components P1, and calculate the margin MG based on the maximum component contact height. The control unit 4 may then add the calculated margin MG to the predicted component contact height D5T1 to set the updated thrust-limit start height D51.

[0070] 8, the control unit 4 updates the thrust limit start height D51 each time the movement process S1 is performed for a specific component storage unit 61 that satisfies the update condition D6. This allows the control unit 4 to set an appropriate thrust limit start height D51 based on the predicted component contact height D5T1 for each specific component storage unit 61 that satisfies the update condition D6.

[0071] Next, the process performed by the control unit 4 when setting the thrust limit start height D5 (D51) will be described in more detail using several examples.

[0072] (First example of setting the thrust limit start height) A first example of how the control unit 4 sets the thrust limit start height D5 will be described with reference to Figures 9 and 10. In the first example, an update condition D6 indicating a condition for updating the thrust limit start height D5 is set based on the number Nx of already-held components P1 corresponding to each row of component storage units 61 arranged along the X-axis direction in the component storage units 61 arranged in a matrix on the tray 6.

[0073] 9 and 10 show an example in which the movement process S1 and the detection process S2 are performed for the component storage units 61(1) to (10) on the tray 6 in the order (1) to (10) indicated by the component storage order D3 in the component storage data D2. In this example, the control unit 4 performs the movement process S1 and the detection process S2 for the component storage units 61(1) to (6) in a first row arranged along the X-axis direction, and then performs the movement process S1 and the detection process S2 for the component storage units 61(7) to (10) in a second row adjacent to the first row in the Y-axis direction. The update condition D6 is set to Nx≧n, where Nx is the number of previously stored components P1 corresponding to the component storage units 61 in each row along the X-axis direction. Figure 9 shows the case where n=3.

[0074] When the update condition D6 is set based on the number Nx of already-held components P1 corresponding to the component storage sections 61 in each row arranged along the X-axis direction, the control section 4 determines whether the update condition D6 is satisfied for each row of the multiple component storage sections 61(1) to (10) arranged in a matrix on the tray 6 along the X-axis direction, sets the thrust limit start height D5 (D50, D51), and performs the movement process S1 and the detection process S2 corresponding to each of the component storage sections 61(1) to (10).

[0075] For example, among the component storage units 61(1) to (6) in the first row, when the movement process S1 is performed for the component storage unit 61(1), there is no component storage unit 61 for which the movement process S1 and the detection process S2 have already been performed. In this case, when the movement process S1 is performed for the component storage unit 61(1), the number Nx of already-held components P1 in the first row is "0." Similarly, when the movement process S1 is performed for the component storage unit 61(2), the movement process S1 and the detection process S2 for the component storage unit 61(1) have already been performed. In this case, when the movement process S1 is performed for the component storage unit 61(2), the number Nx of already-held components P1 in the first row is "1." Furthermore, when the movement process S1 is performed for the component storage unit 61(3), the movement process S1 and the detection process S2 for the component storage units 61(1) and (2) have already been performed. In this case, when the movement process S1 is performed for the component storage unit 61(3), the number Nx of already held components P1 in the first row is "2".

[0076] That is, when the movement process S1 is performed for the component storage units 61(1) to (6) in the first row, the number Nx of already-held components P1 in the first row is less than "3." Therefore, the control unit 4 determines that the component storage units 61(1) to (3) in the first row do not satisfy the update condition D6 of "Nx ≧ 3." On the other hand, when the movement process S1 is performed for the component storage units 61(1) to (6) in the first row, the number Nx of already-held components P1 in the first row is "3" or greater. Therefore, the control unit 4 determines that the component storage units 61(4) to (6) in the first row satisfy the update condition D6 of "Nx ≧ 3."

[0077] Furthermore, when the movement process S1 is performed for the component storage units 61(7)-(10) in the second row, the number Nx of already-held components P1 in the second row is less than "3." Therefore, the control unit 4 determines that the component storage units 61(7)-(9) in the second row do not satisfy the update condition D6 of "Nx≧3." On the other hand, when the movement process S1 is performed for the component storage unit 61(10) in the component storage units 61(7)-(10) in the second row, the number Nx of already-held components P1 in the second row is "3" or more. Therefore, the control unit 4 determines that the component storage unit 61(10) in the second row satisfies the update condition D6 of "Nx≧3."

[0078] 10, for the component storage units 61(1)-(6) in the first row that do not satisfy the update condition D6, the control unit 4 performs the movement process S1 using the thrust limit start height D5 stored in the memory unit 3 as is, and then detects the component contact height D5T corresponding to the already-held component P1 in the subsequent detection process S2. Meanwhile, for a specific component storage unit 61(4)-(6) in the first row that satisfies the update condition D6, the control unit 4 calculates a least-squares line LSL by the least-squares method based on the multiple component contact heights D5T corresponding to the already-held component P1 in the first row. The control unit 4 then calculates a predicted component contact height D5T1 corresponding to the specific component storage unit 61(4)-(6) that satisfies the update condition D6 based on the least-squares line LSL, and performs the movement process S1 using the updated thrust limit start height D51 based on the predicted component contact height D5T1.

[0079] For the component storage sections 61(7)-(9) in the second row that do not satisfy the update condition D6, the control unit 4 can set the thrust limit start height D50 based on the component contact height D5T detected in the detection process S2 for the component storage sections 61(1)-(3) in the first row adjacent in the Y-axis direction. Specifically, the control unit 4 calculates a margin line MGL parallel to the least-squares line LSL by adding a predetermined margin MGS to the least-squares line LSL based on the component contact height D5T of the first row, and sets the thrust limit start height D50 for each component storage section 61(7)-(9) on the margin line MGL. Alternatively, the control unit 4 may set the thrust limit start height D50 for the component storage section 61(7) adjacent in the Y-axis direction to the component contact height D5T corresponding to the component storage section 61(1) by adding the predetermined margin MGS to the component contact height D5T corresponding to the component storage section 61(1). Similarly, the control unit 4 sets the value obtained by adding a predetermined margin MGS to the component contact height D5T corresponding to the component storage section 61(2) as the thrust limit start height D50 corresponding to the component storage section 61(8) adjacent to the component storage section 61(2) in the Y-axis direction, and sets the value obtained by adding a predetermined margin MGS to the component contact height D5T corresponding to the component storage section 61(3) as the thrust limit start height D50 corresponding to the component storage section 61(9) adjacent to the component storage section 61(3) in the Y-axis direction.

[0080] When the thrust limit start height D50 is set for the component storage units 61(7)-(9) in the second row that do not satisfy the update condition D6, the control unit 4 performs the movement process S1 using the set thrust limit start height D50, and then detects the component contact height D5T corresponding to the already-held component P1 in the second row in the subsequent detection process S2. Meanwhile, for a specific component storage unit 61(10) in the second row that satisfies the update condition D6, the control unit 4 calculates a least-squares line LSL using the least-squares method based on the multiple component contact heights D5T corresponding to the already-held component P1 in the second row. The control unit 4 then calculates a predicted component contact height D5T1 corresponding to the specific component storage unit 61(10) that satisfies the update condition D6 based on the least-squares line LSL, and performs the movement process S1 using the updated thrust limit start height D51 based on the predicted component contact height D5T1.

[0081] As described above, the control unit 4 updates the thrust limit start height D51 corresponding to the specific component storage units 61(4)-(6) in the first row and the specific component storage unit 61(10) in the second row that satisfy the update condition D6 based on the predicted component contact height D5T1. This allows the thrust limit start height D51 corresponding to the specific component storage units 61(4)-(6) and 61(10) to be set to an appropriate value based on the predicted component contact height D5T1. Therefore, when the mounting head 251 corresponding to the specific component storage units 61(4)-(6) and 61(10) moves downward during the component holding operation, the thrust limit of the mounting head 251 effectively functions from the position of the updated thrust limit start height D51, preventing damage to the component P. Furthermore, the deceleration time of the descent speed of the mounting head 251 when the thrust limit is set is appropriate, preventing a decrease in the efficiency of the component holding operation.

[0082] (Second example of setting the thrust limit start height) A second example of how the control unit 4 sets the thrust limit start height D5 will be described with reference to Fig. 11. In the second example, an update condition D6 indicating the condition for updating the thrust limit start height D5 is set based on the number Nxy of already-held components P1 corresponding to the multiple component storage sections 61 arranged in a matrix on the tray 6.

[0083] 11 shows an example in which the movement process S1 and the detection process S2 are performed for the component storage sections 61(1) to (8) on the tray 6 in the order indicated by the component storage order D3 in the component storage data D2. The update condition D6 is set to Nxy≧n, and FIG. 11 shows the case where n=7. In this case, the control unit 4 determines whether the update condition D6 is satisfied for each of the component storage sections 61(1) to (8) arranged in a matrix on the tray 6, sets the thrust limit start height D5 (D51), and performs the movement process S1 and the detection process S2 for each of the component storage sections 61(1) to (8).

[0084] For example, when the moving process S1 is performed for the component storage units 61(6) among the component storage units 61(1) to (8) on the tray 6, the moving process S1 and the detection process S2 have already been performed for the component storage units 61(1) to (5). In this case, when the moving process S1 is performed for the component storage unit 61(6), the number Nxy of already-held components P1 for all the component storage units 61 on the tray 6 is "5." Similarly, when the moving process S1 is performed for the component storage unit 61(7), the moving process S1 and the detection process S2 have already been performed for the component storage units 61(1) to (6). In this case, when the moving process S1 is performed for the component storage unit 61(7), the number Nxy of already-held components P1 for all the component storage units 61 on the tray 6 is "6." That is, when the movement process S1 is performed for the component storage units 61(1) to (7) in the component storage units 61(1) to (8) on the tray 6, the number Nxy of already-held components P1 is less than 7. Therefore, the control unit 4 determines that the component storage units 61(1) to (7) do not satisfy the update condition D6, "Nxy≧7."

[0085] On the other hand, when the movement process S1 is performed for the component storage section 61(8) among the component storage sections 61(1) to (8) on the tray 6, the movement process S1 and the detection process S2 have already been performed for the component storage sections 61(1) to (7). In this case, when the movement process S1 is performed for the component storage section 61(8), the number Nxy of already held components P1 for all the component storage sections 61 on the tray 6 is "7." Therefore, the control section 4 determines that the component storage section 61(8) satisfies the update condition D6 of "Nxy≧7."

[0086] As shown in Figure 11, for component storage sections 61(1) to (7) among component storage sections 61(1) to (8) that do not satisfy update condition D6, control section 4 performs movement process S1 using the thrust limit start height D5 stored in memory section 3 as is, and then detects the component contact height D5T corresponding to the already held component P1 in the subsequent detection process S2.

[0087] On the other hand, for a specific component storage unit 61(8) among the component storage units 61(1) to (8) that satisfies the update condition D6, the control unit 4 calculates a least-squares plane using the least-squares method based on the multiple component contact heights D5T corresponding to the already-held component P1.The control unit 4 then calculates a predicted component contact height D5T1 corresponding to the specific component storage unit 61(8) that satisfies the update condition D6 based on the least-squares plane, and performs the movement process S1 using the updated thrust limit start height D51 based on the predicted component contact height D5T1.

[0088] As described above, the control unit 4 updates the thrust limit start height D51 corresponding to a specific component storage unit 61(8) that satisfies the update condition D6 based on the predicted component contact height D5T1. This allows the thrust limit start height D51 corresponding to the specific component storage unit 61(8) to be set to an appropriate value based on the predicted component contact height D5T1. Therefore, when the mounting head 251 corresponding to the specific component storage unit 61(8) moves downward during its component holding operation, the thrust limit of the mounting head 251 effectively functions from the position of the updated thrust limit start height D51, preventing damage to the component P. Furthermore, the deceleration time of the descent speed of the mounting head 251 in the thrust-limited state becomes appropriate, preventing a decrease in the efficiency of the component holding operation.

[0089] (Third example of setting the thrust limit start height) A third example of the control unit 4 setting the thrust limit start height D5 will be described with reference to Fig. 12. In the third example, an update condition D6 indicating a condition for updating the thrust limit start height D5 is set by a first number of already-held components Nx indicating the number of already-held components P1 corresponding to the component storage units 61 in each row arranged along the X-axis direction in the plurality of component storage units 61 arranged in a matrix on the tray 6, and a second number of already-held components Ny indicating the number of already-held components P1 corresponding to the component storage units 61 in each column arranged along the Y-axis direction.

[0090] 12 shows an example in which the movement process S1 and the detection process S2 are performed for each of the component storage sections 61(1) to (7) on the tray 6 in the order indicated by the component storage order D3 in the component storage data D2. The update condition D6 is set so that the first number of already-held components Nx is Nx≧n and the second number of already-held components Ny is Ny≧m, with n=2 and m=1 shown in FIG. 12. In this case, the control unit 4 determines whether the update condition D6 is satisfied for each of the component storage sections 61(1) to (7) arranged in a matrix on the tray 6, sets the thrust limit start height D5 (D51), and performs the movement process S1 and the detection process S2 for each of the component storage sections 61(1) to (7).

[0091] When the movement process S1 is performed for the component storage units 61(1) to (7) on the tray 6 corresponding to the component storage units 61(1) and (2), the first number Nx of already-held components in the X-axis direction is less than "2," and the second number Ny of already-held components in the Y-axis direction is "0," which is less than "1." Therefore, the control unit 4 determines that the component storage units 61(1) and (2) do not satisfy the update condition D6, "Nx≧2, Ny≧1."

[0092] When the movement process S1 is performed for the component storage units 61(3) and (4) among the component storage units 61(1) to (7) on the tray 6, the first number Nx of already-held components in the X-axis direction is equal to or greater than "2," and the second number Ny of already-held components in the Y-axis direction is equal to "0" and less than "1." Therefore, the control unit 4 determines that the component storage units 61(3) and (4) do not satisfy the update condition D6 because "Nx ≥ 2" is satisfied but "Ny ≥ 1" is not satisfied.

[0093] When the movement process S1 is performed for the component storage units 61(5) and (6) among the component storage units 61(1) to (7) on the tray 6, the first number Nx of already-held components in the X-axis direction is less than 2, and the second number Ny of already-held components in the Y-axis direction is 1, which is equal to or greater than 1. Therefore, the control unit 4 determines that the component storage units 61(5) and (6) do not satisfy the update condition D6 because they satisfy "Ny ≥ 1" but do not satisfy "Nx ≥ 2."

[0094] When the movement process S1 is performed for the component storage section 61(7) among the component storage sections 61(1) to (7) on the tray 6, the first number Nx of already held components in the X-axis direction is equal to or greater than "2," and the second number Ny of already held components in the Y-axis direction is equal to or greater than "1." Therefore, the control section 4 determines that the component storage section 61(7) satisfies the update condition D6, "Nx≧2, Ny≧1."

[0095] As shown in Figure 12, for the component storage sections 61(1) to (7) that do not satisfy the update condition D6, the control unit 4 performs a movement process S1 using the thrust limit start height D5 stored in the memory unit 3, and then detects the component contact height D5T corresponding to the already held component P1 in the subsequent detection process S2.

[0096] On the other hand, for a specific component storage unit 61(7) among the component storage units 61(1) to (7) that satisfies the update condition D6, the control unit 4 calculates a least-squares plane using the least-squares method based on the multiple component contact heights D5T corresponding to the already-held component P1.The control unit 4 then calculates a predicted component contact height D5T1 corresponding to the specific component storage unit 61(7) that satisfies the update condition D6 based on the least-squares plane, and performs the movement process S1 using the updated thrust limit start height D51 based on the predicted component contact height D5T1.

[0097] As described above, the control unit 4 updates the thrust limit start height D51 corresponding to a specific component storage unit 61(7) that satisfies the update condition D6 based on the predicted component contact height D5T1. This allows the thrust limit start height D51 corresponding to the specific component storage unit 61(7) to be set to an appropriate value based on the predicted component contact height D5T1. Therefore, when the mounting head 251 corresponding to the specific component storage unit 61(7) moves downward during its component holding operation, the thrust limit of the mounting head 251 effectively functions from the position of the updated thrust limit start height D51, preventing damage to the component P. Furthermore, the deceleration time of the descent speed of the mounting head 251 in the thrust-limited state becomes appropriate, preventing a decrease in the efficiency of the component holding operation.

[0098] (Fourth example of setting the thrust limit start height) A fourth example of the control unit 4 setting the thrust limit start height D5 will be described with reference to FIG. 13. In this example, the update condition D6, which indicates the condition for updating the thrust limit start height D5, is set based on the number Nxy of already-held components P1 within a predetermined range around the component storage unit 61 controlled by the mounting head 251 of the control unit 4, in the component storage units 61 arranged in a matrix on the tray 6. Specifically, the update condition D6 is set based on the number Nxy of already-held components P1 within a Manhattan distance L around the component storage unit 61 controlled by the mounting head 251 of the control unit 4. The Manhattan distance L between two component storage units 61 on the tray 6 is expressed as the sum of the absolute values ​​of the differences in the coordinates of each component storage unit 61. For example, the Manhattan distance L between the component storage unit 61 at coordinates (x1, y1) and the component storage unit 61 at coordinates (x2, y2) on the tray 6 is "|x1-x2|+|y1-y2|".

[0099] FIG. 13 shows an example in which the movement process S1 and the detection process S2 are performed for each of the component storage sections 61(1) to (18) on the tray 6 in the order indicated by the component storage order D3 in the component storage data D2 (1) to (18). The update condition D6 is set such that the number Nxy of already-held components P1 within a predetermined range around the component storage section 61 to be controlled is Nxy≧n, and FIG. 13 shows a case in which n=4. The predetermined range around the component storage section 61 to be controlled is set as a range enclosed by a circle with a radius corresponding to one component, with the component storage section 61 as the base. In this case, the control unit 4 determines whether the update condition D6 is satisfied for each of the component storage sections 61(1) to (18) arranged in a matrix on the tray 6, sets a thrust limit start height D5 (D51), and performs the movement process S1 and the detection process S2 for each of the component storage sections 61(1) to (18).

[0100] When the movement process S1 is performed for the component storage sections 61(1) to (18) on the tray 6, namely, the component storage sections 61(1) to (7), the component storage sections 61(12), (13), and the component storage section 61(18), the number Nxy of already-held components P1 within a predetermined range around each of the component storage sections 61 controlled by the movement process S1 is less than 4. Therefore, the control section 4 determines that the component storage sections 61(1) to (7), the component storage sections 61(12), (13), and the component storage section 61(18) do not satisfy the update condition D6, "Nxy ≧ 4 within the predetermined range."

[0101] When the movement process S1 is performed for the component storage section 61(8) among the component storage sections 61(1) to (18) on the tray 6, the movement process S1 and the detection process S2 have already been performed for the component storage sections 61(1) to (3) and the component storage section 61(7) within a predetermined range around the component storage section 61(8). In this case, when the movement process S1 is performed for the component storage section 61(8), the number Nxy of already held components P1 within the predetermined range around the component storage section 61(8) is "4," which is greater than or equal to "4." Therefore, the control section 4 determines that the component storage section 61(8) satisfies the update condition D6, "Nxy ≧ 4 within the predetermined range." Similarly, when the movement process S1 is performed for the component storage units 61(9)-(11) and the component storage units 61(14)-(17) among the component storage units 61(1)-(18) on the tray 6, the number Nxy of already-held components P1 within a predetermined range around each component storage unit 61 controlled by the movement process S1 is equal to or greater than 4. Therefore, the control unit 4 determines that the component storage units 61(9)-(11) and the component storage units 61(14)-(17) satisfy the update condition D6, "Nxy≧4 within the predetermined range."

[0102] As shown in Figure 13, for component storage sections 61(1) to (18) that do not satisfy update condition D6, such as component storage sections 61(1) to (7), component storage sections 61(12), (13), and component storage section 61(18), the control section 4 performs movement processing S1 using the thrust limit start height D5 stored in memory section 3, and then detects the component contact height D5T corresponding to the already held component P1 in the subsequent detection processing S2.

[0103] On the other hand, for specific component storage sections 61(8)-(11), (14)-(17) among the component storage sections 61(1)-(18) that satisfy the update condition D6, the control section 4 calculates a least-squares plane using the least-squares method based on the multiple component contact heights D5T corresponding to the already-held component P1.The control section 4 then calculates a predicted component contact height D5T1 corresponding to the specific component storage section 61(8)-(11), (14)-(17) that satisfies the update condition D6 based on the least-squares plane, and performs the movement process S1 using the updated thrust limit start height D51 based on the predicted component contact height D5T1.

[0104] As described above, the control unit 4 updates the thrust limit start height D51 corresponding to the specific component storage units 61(8)-(11), (14)-(17) that satisfy the update condition D6 based on the predicted component contact height D5T1. This allows the thrust limit start height D51 corresponding to the specific component storage units 61(8)-(11), (14)-(17) to be set to an appropriate value based on the predicted component contact height D5T1. Therefore, when the placement head 251 corresponding to the specific component storage unit 61(8)-(11), (14)-(17) moves downward during its component holding operation, the thrust limit of the placement head 251 effectively functions from the position of the updated thrust limit start height D51, preventing damage to the component P. Furthermore, the deceleration time of the descent speed of the placement head 251 when the thrust limit is set is appropriate, preventing a decrease in the efficiency of the component holding operation. [Explanation of symbols]

[0105] 1. Component Mounting Machine 2 Mounting machine body 24 Parts supply device 25 Head Unit 251 Mounting Head 251A Holding surface 3 Storage section 4. Control section 5 palettes 6 trays 61 Parts storage section

Claims

1. a component supply device that supplies components by moving a pallet on which a tray having a plurality of component storage sections for storing components is placed; a mounting head having a holding surface for holding a component, and for mounting the component held on the holding surface onto a board, the mounting head being movable in a vertical direction perpendicular to the holding surface, and performing a component holding operation for each of a plurality of component holding sections by moving the holding surface downward until it comes into contact with a component while the holding surface is positioned at a reference position above the component holding section; a memory unit that stores a thrust limit start height that indicates, as a height from the pallet, a start position at which a limit is applied to the thrust when the mounting head moves downward in the component holding operation, and an update condition that indicates a condition for updating the thrust limit start height by the number of components already held by the mounting head; a control unit that determines whether the update condition is satisfied for each of the component storage units, and controls the component holding operation of the mounting head using the thrust limit start height, The control unit a movement process in which the mounting head is moved downward while the mounting head is disposed at the reference position, and thrust restriction of the mounting head is initiated when the holding surface reaches a position at the thrust restriction initiation height, and the thrust restriction state is maintained until the holding surface comes into contact with a component in the component storage unit; a detection process for detecting a component contact height, which indicates a position where the holding surface contacts a component in the component storage unit as a height from the pallet, based on a change in thrust from a thrust-limited state in the mounting head; a component mounter that, when performing the movement process in response to a specific component storage unit that satisfies the update condition, calculates a predicted component contact height that assumes contact of the holding surface with the component in the specific component storage unit based on the component contact height detected in the detection process corresponding to the already held component, and updates the thrust limit start height based on the predicted component contact height.

2. 2. The mounter according to claim 1, wherein the control unit calculates the predicted component contact height by a least squares method based on a plurality of the component contact heights corresponding to a plurality of the already held components.

3. The component mounter according to claim 1 , wherein the control unit sets a value obtained by adding a certain margin to the predicted component contact height as the updated thrust limit start height.

4. 2. The component mounter according to claim 1, wherein the control unit extracts a maximum component contact height that indicates a maximum value from among a plurality of component contact heights corresponding to a plurality of the already-held components, calculates a margin based on the maximum component contact height, and sets a value obtained by adding the calculated margin to the predicted component contact height as the updated thrust limit start height.

5. The component mounter according to claim 1 , wherein the control unit updates the thrust limit start height each time the movement process is performed in response to the specific component storage unit that satisfies the update condition.

6. the component storage sections are arranged in a matrix on the tray in a first direction and a second direction that are orthogonal to each other, The component mounter according to any one of claims 1 to 5, wherein the update condition is set by the number of already-held components corresponding to each row of component storage units arranged along the first direction in a plurality of component storage units arranged in a matrix.

7. The control unit In controlling the component holding operation of the mounting head, when the movement process and the detection process are performed corresponding to the component storage units of a first row arranged along the first direction, and then the movement process and the detection process are performed corresponding to the component storage units of a second row adjacent to the first row in the second direction, For a component storage unit in the second row that does not satisfy the update condition, the thrust limit start height is set based on the component contact height detected in the detection process corresponding to the component storage unit in the first row adjacent in the second direction, and the movement process is performed, and the component contact height corresponding to the already-held component is detected in the subsequent detection process.

7. The component mounter according to claim 6, wherein for a component storage unit in the second row that satisfies the update condition, the predicted component contact height is calculated based on the component contact height corresponding to the already held component, and the movement processing is performed using the thrust limit start height after updating based on the predicted component contact height.

8. the component storage sections are arranged in a matrix on the tray in a first direction and a second direction that are orthogonal to each other, 6. The component mounter according to claim 1, wherein the update condition is set based on the number of already-held components corresponding to the plurality of component storage units arranged in a matrix.

9. The control unit For a component storage unit that does not satisfy the update condition among the plurality of component storage units, the movement process is performed using the thrust limit start height stored in the storage unit as is, and the component contact height corresponding to the already-held component is detected in the subsequent detection process; 9. The component mounter according to claim 8, wherein for a component storage unit among the plurality of component storage units that satisfies the update condition, the predicted component contact height is calculated based on the component contact height corresponding to the already held component, and the movement processing is performed using the thrust limit start height after update based on the predicted component contact height.

10. the component storage sections are arranged in a matrix on the tray in a first direction and a second direction that are orthogonal to each other, The component mounter according to any one of claims 1 to 5, wherein the update condition is set by a first number of already-held components indicating the number of already-held components corresponding to component storage sections in each row arranged along the first direction in the plurality of component storage sections arranged in a matrix, and a second number of already-held components indicating the number of already-held components corresponding to component storage sections in each column arranged along the second direction.

11. The control unit For a component storage unit that does not satisfy the update condition among the plurality of component storage units, the movement process is performed using the thrust limit start height stored in the storage unit as is, and the component contact height corresponding to the already-held component is detected in the subsequent detection process; 11. The component mounter according to claim 10, wherein for a component storage unit among the plurality of component storage units that satisfies the update condition, the predicted component contact height is calculated based on the component contact height corresponding to the already held component, and the movement processing is performed using the thrust limit start height after update based on the predicted component contact height.

12. the component storage sections are arranged in a matrix on the tray in a first direction and a second direction that are orthogonal to each other, The component mounter according to any one of claims 1 to 5, wherein the update condition is set based on the number of already-held components within a predetermined range around a component storage unit that is the target of control of the mounting head by the control unit, in a plurality of component storage units arranged in a matrix.

13. The control unit For a component storage unit that does not satisfy the update condition among the plurality of component storage units, the movement process is performed using the thrust limit start height stored in the storage unit as is, and the component contact height corresponding to the already-held component is detected in the subsequent detection process; 13. The component mounter according to claim 12, wherein for a component storage unit among the plurality of component storage units that satisfies the update condition, the predicted component contact height is calculated based on the component contact height corresponding to the already held component, and the movement processing is performed using the thrust limit start height after updating based on the predicted component contact height.

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