Rotary head of a surface mounter

A rotary head of a surface mounter includes a rotating body, an N-shaft servo motor configured to rotate and drive the rotating body and a plurality of suction nozzles attached to the rotating body in such a manner as to be movable in a direction of a rotation axis. The plurality of suction nozzles are arranged on a virtual circle with the rotation axis as the center, and the plurality of suction nozzles are configured to hold and release a component. The rotary head of a surface mounter further includes a Z-axis drive device including a Z-axis linear motor. The Z-axis drive device is configured to use the Z-axis linear motor to move, in the direction of the rotation axis, the suction nozzle that has moved to a predetermined drive position on the virtual circle.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a National Stage of International Patent Application No. PCT/JP2015/077955, filed Oct. 1, 2015, the entire content of which is incorporated herein by reference.

BACKGROUND

Technical Field

The technology disclosed in the description relates to a rotary head and a surface mounter.

Background Art

Among surface mounters that are configured to mount electronic components onto printed boards, those which include a mounting head (what is called a rotary head) having a rotating body and a plurality of suction nozzles (component holding members) attached to the rotating body in such a manner as to be movable in a direction of a rotation axis, arranged on a virtual circle with the rotation axis as the center, and configured to cause a component to adhere to a distal end portion thereof by using negative pressure and release the adhering component by using positive pressure are conventionally known.

Among rotary heads of this type, those which include a suction nozzle drive unit that moves the suction nozzle in the direction of the rotation axis of the rotating body, and a valve drive unit that moves, to a positive or negative pressure supply position, a valve for switching pressure supplied to the suction nozzle between the positive pressure and the negative pressure are known as described, for example, in Japanese Unexamined Patent Publication No. 2013-69798. Specifically, a double rotary head described in Japanese Unexamined Patent Publication No. 2013-69798 includes a holding shaft lifting device that advances and retreats a nozzle holding shaft by an electric motor, and a switching device that switches the position of a valve spool by a linear motor.

SUMMARY

If a rotary motor such as an electric motor is used to drive a suction nozzle or a valve, a mechanism is required which converts the rotary motion of the electric motor into the linear motion of the suction nozzle or valve. Accordingly, the drive unit results in being increased in size. Contrarily, the linear motor does not require such a mechanism. Accordingly, the drive unit can be reduced in size. Consequently, the rotary head can be reduced in size.

The rotary head, however, needs to cause one drive unit to drive a plurality of suction nozzles or a plurality of valves; therefore, the operating load of the drive unit is increased. Hence, if a linear motor is used as a drive source of the drive unit, a coil of the linear motor generates heat to thermally deform the rotary head. Consequently, the precision of placement of components may be reduced. Especially, aluminum has a high linear expansion coefficient. Accordingly, when aluminum is used for a constituent component of the drive unit to reduce the weight of the rotary head, thermal deformation is likely to occur.

The above-mentioned double rotary head described in Japanese Unexamined Patent Publication No. 2013-69798 has room for improvement in terms of preventing such a reduction in the precision of placement due to heat generated by the linear motor.

In the description, a technology is disclosed which prevents a reduction in the precision of placement due to heat generated by a linear motor in a rotary head that drives a component holding member or valve by the linear motor, and a surface mounter.

The rotary head disclosed in the description is a rotary head of a surface mounter including a rotating body, a rotation drive unit configured to rotate and drive the rotating body, and a plurality of component holding members attached to the rotating body in such a manner as to be movable in a direction of a rotation axis. The plurality of component holding members are arranged on a virtual circle with the rotation axis as the center, with the plurality of component holding members being configured to hold and release a component. The rotary head of a surface mounter further includes a holding member drive unit including an opposed linear motor with a core. The holding member drive unit is configured to use the opposed linear motor with the core to move, in the direction of the rotation axis, the component holding member that has moved to a predetermined drive position on the virtual circle.

The above-mentioned linear motor disclosed in Japanese Unexamined Patent Publication No. 2013-69798 is a cylindrical linear motor, what is called a linear shaft motor. Specifically, the linear motor disclosed in Japanese Unexamined Patent Publication No. 2013-69798 is provided on the surface of a rod with a plurality of ring-shaped permanent magnets as a stator. A plurality of movers including coils is fitted to the outside of the stator with a gap therebetween. These movers move along an axial direction of the stator. The linear shaft motor generally has a low thrust density (the thrust that can be generated in relation to the volume of the motor). Accordingly, when the operating load is increased, heat is likely to be generated.

Contrarily, the opposed linear motor with the core has a higher thrust density than the linear shaft motor. Accordingly, when the motor is of the same size, even if its operating load is increased, heat is unlikely to be generated. Hence, according to the rotary head, it is possible to prevent a reduction in the precision of placement due to heat generated by the linear motor as compared to a case where the linear shaft motor is used.

Moreover, the holding member drive unit may be disposed around the rotating body on any virtual straight line orthogonal to the rotation axis in an orientation where a mover of the opposed linear motor with the core of the holding member drive unit moves in the direction of the rotation axis, and in an orientation where a stator and the mover of the opposed linear motor with the core are arranged in a tangent direction to the virtual circle at a point of intersection of the virtual circle and the virtual straight line.

According to the rotary head, the holding member drive unit is disposed around the rotating body in the orientation where the mover moves in the direction of the rotation axis. Accordingly, for example, it is possible to prevent the holding member drive unit from extending out in a direction of the virtual straight line as compared to, for example, a case where the holding member drive unit is disposed in an orientation where the mover moves in the direction of the virtual straight line. Furthermore, according to the rotary head, the holding member drive unit is disposed on any virtual straight line orthogonal to the rotation axis of the rotating body in the orientation where the stator and the mover are arranged in the tangent direction at the point of intersection of the above-mentioned virtual circle and the virtual straight line. Accordingly, it is possible to further prevent the holding member drive unit from extending out in the direction of the virtual straight line as compared to a case where the holding member drive unit is disposed in an orientation where the stator and the mover are inclined against the tangent direction (for example, a case where the holding member drive unit is disposed in an orientation where the stator and the mover are arranged in the direction of the virtual straight line).

In this manner, according to the rotary head, it is possible to prevent the holding member drive unit from extending out. Accordingly, it is possible to reduce a circle circumscribing the holding member drive unit (an outermost circle) with the rotation axis of the rotating body as the center. In other words, the rotary head can be made compact when viewed from the direction of the rotation axis of the rotating body. Consequently, it is possible to cause the rotary head to have a large range of motion in a direction perpendicular to the rotation axis of the rotating body.

Moreover, a first to-be-read member provided on an output shaft to which the mover of the opposed linear motor with the core is attached. The first to-be-read member extends substantially parallel to the output shaft on a side opposite to the stator of the opposed linear motor with the core across the output shaft. Also, a first position detection unit disposed on the side opposite to the output shaft across the first to-be-read member and configured to detect a position of the first to-be-read member may be further included.

For example, the output shaft is formed in a straight shape extending straight in the direction of the rotation axis of the rotating body. It is also possible to dispose the stator and the first position detection unit side by side in the direction of the rotation axis by using the extension portion as the to-be-read member. However, in this case, the output shaft is long in the direction of the rotation axis. Accordingly, it may be difficult to secure a space for disposing the holding member drive unit.

According to the rotary head, the output shaft is provided, on the side opposite to the stator across the output shaft, with the first to-be-read member extending substantially parallel to the output shaft. Accordingly, the length of the output shaft in the direction of the rotation axis can be reduced. Consequently, even if it is difficult to secure the space for disposing the holding member drive unit when the output shaft is long in the direction of the rotation axis, it is easy to secure the space for disposing the holding member drive unit.

Moreover, the component holding member may be a suction nozzle that causes the component to adhere thereto by using negative pressure and releases the adhering component by using positive pressure. Also, the rotary head may further include a plurality of valves attached to the rotating body in such a manner as to be movable between a negative pressure supply position that supplies the negative pressure to the suction nozzle and a positive pressure supply position that supplies the positive pressure to the suction nozzle, and a valve drive unit including an opposed linear motor with a core. The valve drive unit is configured to use the opposed linear motor with the core to move the valve corresponding to the suction nozzle that has moved to the drive position, between the negative pressure supply position and the positive pressure supply position.

The opposed linear motor with the core has a high thrust density than a linear shaft motor. Accordingly, when the motor is of the same size, even if its operating load is increased, heat is unlikely to be generated. Accordingly, according to the rotary head, it is possible to prevent a reduction in the precision of placement due to heat generated by the linear motor.

Moreover, the rotary head disclosed in the description is a rotary head of a surface mounter including a rotating body, a rotation drive unit configured to rotate and drive the rotating body, and a plurality of suction nozzles attached to the rotating body in such a manner as to be movable in a direction of a rotation axis. The plurality of suction nozzles are arranged on a virtual circle with the rotation axis as the center. Also, the plurality of suction nozzles are configured to cause a component to adhere to a distal end portion thereof by using negative pressure and release the adhering component by using positive pressure. The rotary head of a surface mounter also includes a holding member drive unit configured to move, in the direction of the rotation axis, the suction nozzle that has moved to a predetermined drive position on the virtual circle, and a plurality of valves attached to the rotating body in such a manner as to be movable between a negative pressure supply position that supplies the negative pressure to the suction nozzle and a positive pressure supply position that supplies the positive pressure to the suction nozzle. The rotary head of a surface mounter further includes a valve drive unit including an opposed linear motor with a core. The valve drive unit is configured to use the opposed linear motor with the core to move the valve corresponding to the suction nozzle that has moved to the drive position, between the negative pressure supply position and the positive pressure supply position.

The opposed linear motor with the core has a higher thrust density than a linear shaft motor. Accordingly, when the motor is of the same size, even if its operating load is increased, heat is unlikely to be generated. Hence, according to the rotary head, it is possible to prevent a reduction in the precision of placement due to heat generated by the linear motor.

Moreover, the valve drive unit may be disposed around the rotating body on any virtual straight line orthogonal to the rotation axis in an orientation where a mover of the opposed linear motor with the core of the valve drive unit moves in the direction of the rotation axis, and in an orientation where a stator and the mover of the opposed linear motor with the core are arranged in a tangent direction to the virtual circle at a point of intersection of the virtual circle and the virtual straight line.

According to the rotary head, the rotary head can be made compact when viewed from the direction of the rotation axis of the rotating body. Consequently, it is possible to cause the rotary head to have a large range of motion in a direction perpendicular to the rotation axis of the rotating body. Moreover, the holding member drive unit and the valve drive unit may overlap each other when viewed from the direction of the rotation axis. If the holding member drive unit and the valve drive unit extend out in different directions when viewed from the direction of the rotation axis of the rotating body, the rotary head results in being increased in size when viewed from the direction of the rotation axis of the rotating body.

Contrarily, according to the rotary head described above, the valve drive unit and the holding member drive unit overlap each other when viewed from the direction of the rotation axis of the rotating body. Accordingly, the direction in which the holding member drive unit extends out is substantially the same as the direction in which the valve drive unit extends out. Hence, the rotary head can be reduced in size when viewed from the direction of the rotation axis of the rotating body as compared to the case where the valve drive unit and the holding member drive unit extend out in directions different from each other. Consequently, it is possible to cause the rotary head to have a large range of motion in the direction perpendicular to the rotation axis.

Moreover, a second to-be-read member provided on an output shaft to which the mover of the opposed linear motor with the core of the valve drive unit is attached. The second to-be-read member extends substantially parallel to the output shaft on a side opposite to the stator of the opposed linear motor with the core across the output shaft. A second position detection unit is disposed on the side opposite to the output shaft across the second to-be-read member and configured to detect a position of the second to-be-read member may be further included.

According to the rotary head described above, even if it is difficult to secure a space for disposing the valve drive unit when the output shaft is long in the direction of the rotation axis, it is easy to secure the space for disposing the valve drive unit.

Moreover, a surface mounter disclosed in the description includes a component mounting device having the rotary head as discussed above, and configured to mount the component onto a board. The surface mounter further includes a component feeding device configured to supply the component to the component mounting device, and a board transfer device configured to transfer the board to a mounting position of the component by the component mounting device.

According to the surface mounter described above, it is possible to prevent a reduction in the precision of placement due to heat generated by the linear motor. According to the rotary head and the surface mounter, which are disclosed in the description, it is possible to prevent a reduction in the precision of placement due to heat generated by the linear motor.

DETAILED DESCRIPTION

An embodiment is described with reference toFIGS. 1 to 13.

(1) Entire Configuration of Surface-Mount Placement Machine

As illustrated inFIG. 1, a surface mounter1according to the embodiment includes a base10, a transfer conveyor20(an example of a board transfer device) for transferring a printed board B1(an example of a board), a component mounting device30for placing an electronic component E1(an example of a component) onto the printed board B1, and component feeding devices40for supplying the electronic component E1to the component mounting device30.

The base10is formed in a rectangular shape in plan view, and a top surface of the base10is flat. Moreover, for example, an unillustrated backup plate for backing the printed board B1up at the time when the electronic component E1is mounted on the printed board B1is provided below the transfer conveyor20on the base10. In the following description, let the long side of the base10(the left-and-right direction inFIG. 1) and the transfer direction of the transfer conveyor20be the X-axis direction, let the short side of the base10(the up-and-down direction inFIG. 1) be the Y-axis direction, and let the up-and-down direction of the base10(the up-and-down direction inFIG. 2) be the Z-axis direction.

The transfer conveyor20is disposed in a substantially center position of the base10in the Y-axis direction, and transfers the printed board B1along the transfer direction (the X-axis direction). The transfer conveyor20includes a pair of conveyor belts22that is driven and circulated in the transfer direction. The printed board B1is set in such a manner as to be disposed on and between both of the conveyor belts22. The printed board B1is carried in to an operation position (a position enclosed by a chain double-dashed line inFIG. 1) on the base10along the conveyor belts22from one side in the transfer direction (the right side illustrated inFIG. 1), and stopped there. After the operation of placing the electronic component E1is performed, the printed board B1is carried out to the other side (the left side illustrated inFIG. 1) along the conveyor belts22.

The component feeding devices40are of a feeder type, and are disposed at four locations in all, arranged side by side in twos in the X-axis direction on both sides (both of the upper and lower sides ofFIG. 1) of the transfer conveyor20. A plurality of feeders42is arranged side by side and attached to each of these component feeding devices40. Each feeder42includes a reel (not illustrated) around which a component supply tape (not illustrated) where a plurality of the electronic components E1is stored is wound, and a motor-operated delivery device (not illustrated) that pulls the component supply tape from the reel. The electronic components E1are supplied, one by one, in a component supply position provided at an end located on the transfer conveyor belt side.

The component mounting device30is configured including a pair of support frames32provided above the base10, the component feeding devices40described below, and the like, a rotary head50, and a rotary head drive mechanism that drives the rotary head50. The support frames32are located on both sides of the base10in the X-axis direction, respectively, and extend in the Y-axis direction. An X-axis servo mechanism and a Y-axis servo mechanism, which configure the rotary head drive mechanism, are provided to the support frame32. The rotary head50is designed to be movable in the X- and Y-axis directions within a fixed range of motion by using the X- and Y-axis servo mechanisms.

The Y-axis servo mechanism includes a Y-axis guide rail33Y, a Y-axis ball screw34Y threadedly engaging with an unillustrated ball nut, and a Y-axis servo motor35Y. A head support36fixed to the ball nut is attached to each Y-axis guide rail33Y. When the Y-axis servo motor35Y is energized and controlled, the ball nut advances and retreats along the Y-axis ball screw34Y. As a result, the head support36fixed to the ball nut, and the rotary head50described below move along the Y-axis guide rail33Y in the Y-axis direction.

The X-axis servo mechanism includes an X-axis guide rail (not illustrated), an X-axis ball screw34X threadedly engaging with an unillustrated ball nut, and an X-axis servo motor35X. The rotary head50is attached to the X-axis guide rail in such a manner as to be movable along an axial direction of the X-axis guide rail. When the X-axis servo motor35X is energized and controlled, the ball nut advances and retreats along the X-axis ball screw34X. As a result, the rotary head50fixed to the ball nut moves along the X-axis guide rail in the X-axis direction.

(2) Configuration of Rotary Head

Next, the configuration of the rotary head50is described in detail. As illustrated inFIG. 2, the rotary head50is formed in an arm shape where a head body portion52being a main body is covered by covers53and54. The rotary head50causes the electronic component E1supplied by the component feeding device40to adhere thereto and mounts the electronic component E1onto the printed board B1. As illustrated inFIG. 4, 18nozzle shafts55in all are supported in the distal end portion of rotary head50in such a manner as to be movable by a rotating body60in the Z-axis direction (the up-and-down direction).

The rotating body60includes a shaft portion62formed in a shaft shape along the Z-axis direction, and a shaft holding portion64provided around the shaft portion62to a lower end portion of the rotary head50and formed in a substantially columnar shape with a larger diameter than the shaft portion62. The shaft portion62of the rotating body60is supported by the head body portion52in such a manner as to be bidirectionally rotatable (that is, pivotable) about the axis of the shaft portion62. The shaft portion62has a double structure. An N-shaft driven gear62N is provided around the axis of the shaft portion62to an upper portion of the inner shaft portion62(hereinafter referred to as the “N shaft”). An R-shaft driven gear62R is provided around the axis of the shaft portion62to an upper portion of the outer shaft portion62(hereinafter referred to as the “R shaft”).

An unillustrated N-shaft drive device (an example of a rotating drive unit) for rotating and driving the rotating body60is disposed in a substantially center portion of the rotary head50in the Z-axis direction. The N-shaft drive device includes an N-shaft servo motor35N (refer toFIG. 7), and an N-shaft drive gear (not illustrated) provided around an output shaft of the N-shaft servo motor35N. The N-shaft drive gear engages with the N-shaft driven gear62N. When the N-shaft servo motor35N is energized and controlled, the rotating body60is rotated at an arbitrary angle about the rotation axis along the Z-axis direction via the rotation and drive of the N-shaft drive gear and the N-shaft driven gear62N.

Eighteen through-holes are formed at regular intervals in the circumferential direction in the shaft holding portion64of the rotating body60. The shaft-shaped nozzle shaft55is held through a tubular shaft holder57in the through-hole in a form of extending along the Z-axis direction while penetrating the shaft holding portion64. As illustrated inFIGS. 4 and 5, a lower end portion of each nozzle shaft55, which protrudes downward from the shaft holding portion64, is provided with a suction nozzle56(an example of a component holding member) that causes the electronic component E1to adhere thereto.

It is designed such that negative or positive pressure is supplied to each suction nozzle56. Each suction nozzle56causes a distal end portion thereof to adhere to and hold the electronic component E1by using the negative pressure, and releases the electronic component E1held at the distal end portion by using the positive pressure. When the rotating body60is rotated by the N-shaft drive device, the suction nozzles56provided to the nozzle shafts55, together with the nozzle shafts55, are rotated about a rotation axis of the rotating body60.

Moreover, as illustrated inFIG. 2, an R-shaft drive device70for rotating and driving each nozzle shaft55about an axis thereof is disposed in the substantially center portion of the rotary head50in the Z-axis direction. The R-shaft drive device70includes an R-shaft servo motor35R, and an R-shaft drive gear72R (refer toFIG. 3) provided around an output shaft of the R-shaft servo motor35R to engage with the R-shaft driven gear62R. An unillustrated common gear is provided to a portion, lower than the R-shaft driven gear62R, of the outer shaft portion62provided with the R-shaft driven gear62R.

On the other hand, as illustrated inFIG. 4, a part of each shaft holder57is provided, around a cylindrical shaft thereof, with a nozzle gear57R. The nozzle gear57R provided to the nozzle shaft55engages with the common gear. When the R-shaft servo motor35R is energized and controlled, the common gear rotates via the rotation and drive of the R-shaft drive gear72R and the R-shaft driven gear62R.

When the common gear rotates, the shaft holders57are rotated by the engagement with the nozzle gears57R. The shaft holder57and the nozzle shaft55are coupled through ball spline coupling. Accordingly, the18nozzle shafts55rotate all at once about axes thereof at the same angle in the same direction with the rotation of the common gear.

Moreover, a spring stop bolt58is threadedly engaged with an upper end portion of each nozzle shaft55. A coiled spring59is disposed on an outer peripheral surface side of each nozzle shaft55. The coiled spring59is disposed in a compressed manner between the spring stop bolt58and the shaft holder57. The nozzle shaft55is biased upward by the elastic force of the coiled spring59.

Moreover, as illustrated inFIGS. 2 to 4, the rotary head50includes two Z-axis drive devices80(an example of holding member drive units) for raising and lowering the nozzle shaft55, among the18nozzle shafts55, that has moved to a specific position (hereinafter referred to as the drive position) on the virtual circle66(refer toFIG. 10) where the nozzle shafts55are arranged, with respect to the rotating body60in a direction along the shaft portion62of the rotating body60(the Z-axis direction and the up-and-down direction). The two Z-axis drive devices80have the same structure as each other, and are symmetrically disposed on both of the left and right sides of the rotary head50with respect to the shaft portion62of the rotating body60, above the nozzle shafts55(refer toFIG. 5).

As illustrated inFIGS. 3 to 5, the Z-axis drive device80includes a box-shaped Z-axis drive source82and a Z-axis moving portion84extending downward from the Z-axis drive source82. A Z-axis linear motor35Z for driving the Z-axis moving portion84with linear motor drive (refer toFIG. 7) is provided in the Z-axis drive source82. The Z-axis moving portion84is supported in such a manner as to be movable with respect to the Z-axis drive source82in the direction along the shaft portion62, and is raised and lowered by the Z-axis drive source82in the direction along the shaft portion62.

Here, the Z-axis linear motor35Z according to the embodiment is an opposed linear motor with a core, and more specifically, an opposed moving magnet linear motor with a core. The opposed moving magnet linear motor with the core is one where a coil as a stator is wound around the core, and a permanent magnet being a mover is provided in such a manner as to be movable in proximity to the coil.

The opposed linear motor with the core may be called an F-type linear motor. Moreover, the opposed linear motor with the core may be of a moving coil type including a permanent magnet as a stator and a coil as a mover. The Z-axis linear motor35Z may be an opposed moving coil linear motor with a core. In terms of the moving coil type, wiring is complicated since an electric wire that energizes the coil moves together with the coil. However, in terms of the moving magnet type, wiring is unnecessary for the moving portion of magnet since the coil is fixed, and accordingly the wiring can be made simple as compared to the moving coil type.

As illustrated inFIGS. 4 and 5, a cam follower86(hereinafter referred to as the “Z-axis cam follower86”) is attached to a lower end portion of the Z-axis moving portion84of the Z-axis drive device80in such a manner as to be rotatable about an axis thereof along the X-axis direction. The Z-axis moving portion84is supported in an upward end position thereof by the Z-axis drive source82in a placement where the Z-axis cam follower86is close to the upper end portion (the spring stop bolt58) of the nozzle shaft55in the drive position (refer toFIG. 5). Hence, rotation about the shaft portion62of each nozzle shaft55is allowed in a state where the Z-axis moving portion84is in the upward end position.

When the Z-axis drive source82lowers the Z-axis moving portion84from the upward end position, the Z-axis cam follower86comes into contact with the upper end portion of the nozzle shaft55in the drive position, and the nozzle shaft55is lowered against the elastic force of the coiled spring59. When the nozzle shaft55is lowered, the suction nozzle56provided to the nozzle shaft55is lowered, and the distal end portion of the suction nozzle56comes close to the printed board B1in the component supply position or operation position of the component feeding device40. When the Z-axis moving portion84is raised from this state, the elastic force return force of the coiled spring59raises the nozzle shaft55and the suction nozzle56.

Furthermore, the rotary head50includes switching devices90for switching pressure supplied to each suction nozzle56between the negative pressure and the positive pressure, as illustrated inFIGS. 4 and 5. Eighteen switching devices90in all are provided, corresponding respectively to the suction nozzles56(the nozzle shafts55). The switching devices90are each provided between two adjacent nozzle shafts55outward of the nozzle shafts55disposed on the virtual circle66and are each spaced evenly on the circumference of a circle with the rotation axis of the virtual circle66as the center along the outer periphery of the shaft holding portion64as in the nozzle shafts55(refer toFIG. 4).

As illustrated inFIG. 6, each switching device90includes a shaft-shaped valve spool92(an example of a valve), and a tubular sleeve94where a lower portion of the valve spool92is housed. The sleeves94are attached respectively in mounting holes provided in the shaft holding portion64. Specifically, the sleeve94is attached such that the entire sleeve94excluding a large-diameter portion98provided at an upper end of the sleeve94is inserted in the mounting hole. A lower portion (a major part excluding a contact portion93of the valve spool92) of the valve spool92with respect to an opening of the large-diameter portion98exposed from the shaft holding portion64is housed in the sleeve94in such a manner as to be movable along a direction of the axis of the valve spool92.

Each valve spool92is disposed in the sleeve94, orienting the axial direction of the valve spool92in the Z-axis direction (the up-and-down direction). The valve spool92moves along the axial direction to switch the pressure of air supplied to each suction nozzle56between the negative pressure and the positive pressure.

Also, as illustrated inFIG. 6, each valve spool92includes, in an upper portion thereof, the substantially horizontal U-shaped contact portion93with which a V-axis cam follower106of a V-axis drive device100described below comes into contact. Each valve spool92is disposed, orienting an open side of the substantially U-shaped contact portion93outward (a side opposite to the shaft portion62side) (refer toFIG. 4). The contact portion93is formed in the substantially horizontal U shape to have a pair of opposed portions93A spaced apart in the axial direction of the valve spool92(the Z-axis direction), extending in a direction orthogonal to the axial direction and facing each other.

An upper end of the valve spool92housed in the sleeve94moves to an upward end position (hereinafter referred to as the “negative pressure supply position201”) being a position indicated by a dot-and-dash line201inFIG. 6, and accordingly the negative pressure is supplied into the sleeve94in the switching device90. Moreover, the upper end of the valve spool92moves to a downward end position (hereinafter referred to as the “positive pressure supply position202”) being a position indicated by a dot-and-dash line202inFIG. 6, and accordingly the positive pressure is supplied into the sleeve94. The negative or positive pressure supplied into each sleeve94is supplied through an unillustrated supply path to the suction nozzle56corresponding to the sleeve94.

Here, in the rotary head50, the supply route for supplying the negative or positive pressure into each sleeve94, and a negative or positive pressure supply mode are described. As illustrated inFIG. 6, each sleeve94is provided with a negative pressure input port94A into which the negative pressure is inputted, a positive pressure input port94B into which the positive pressure is inputted, and an output port (not illustrated) from which the negative or positive pressure inputted from the negative pressure input port94A or the positive pressure input port94B is outputted. The output port communicates with its corresponding suction nozzle56.

Moreover, a first negative pressure supply path62A through which the negative pressure is supplied is provided inside the inner shaft portion62, and a first positive pressure supply path62B through which the positive pressure is supplied is provided outside the rotating body60(refer toFIG. 2). A plurality of second negative pressure supply paths64A through which the negative pressure is supplied, the plurality of second negative pressure supply paths64A corresponding respectively to the sleeves94, and two second positive pressure supply paths64B through which the positive pressure is supplied, the two second positive pressure supply paths64B communicating with the first positive pressure supply path62B, are provided in the shaft holding portion64.

The first negative pressure supply path62A is configured in such a manner as to always communicate with all the second negative pressure supply paths64A in a lower end portion of the first negative pressure supply path62A irrespective of the rotation/non-rotation of the shaft portion62. Moreover, each second negative pressure supply path64A communicates with the negative pressure input port94A of the sleeve94where the valve spool92is housed, while the valve spool92is in the negative pressure supply position201. Therefore, while the valve spool92is in the negative pressure supply position201, the negative pressure is always supplied to the suction nozzle56corresponding to the valve spool92(the switching device90) irrespective of whether or not each suction nozzle56is rotating about the axis of the rotating body60.

The two second positive pressure supply paths64B are provided in the shaft holding portion64, respectively in positions corresponding to the drive positions where each Z-axis drive device80raises and lowers the nozzle shaft55in the Z-axis direction. While the valve spool92corresponding to the suction nozzle56in the drive position is in the positive pressure supply position202, both of the second positive pressure supply paths64B communicate with the positive pressure input port94B of the sleeve94where the valve spool92is housed. Therefore, while the valve spool92is in the positive pressure supply position202, only when the suction nozzle56corresponding to the valve spool92is in the drive position, the positive pressure is supplied to the suction nozzle56from the output port.

As described above, in the rotary head50, the negative pressure is always supplied to the suction nozzles56corresponding to the valve spools92in the negative pressure supply position201. Accordingly, it is possible to prevent the electronic components E1adhered to a plurality of the suction nozzles56from falling off during, for example, travel of the rotary head50. Moreover, as described above, the positive pressure is supplied to the suction nozzle56corresponding to the valve spool92in the positive pressure supply position202only in the predetermined case. Accordingly, only the electronic component E1targeted to be mounted can be mounted onto the printed board B1by using the positive pressure.

As illustrated inFIG. 6, a plurality of outer seal rings96is disposed on an outer peripheral surface of each sleeve94and is spaced apart in the Z-axis direction. The outer seal ring96is an annular ring formed of an elastic body such as rubber, and achieves a function of sealing a gap between the sleeve94and the mounting hole of the shaft holding portion64.

Moreover, unillustrated inner seal rings are disposed at a plurality of locations along the axial direction on an inner peripheral side of the sleeve94. The inner seal ring is an annular ring formed of an elastic body such as rubber, and is attached to an outer surface of the valve spool92. The inner seal ring achieves a function of sealing a gap between an inner peripheral surface of the sleeve94and the valve spool92. As a result, the leaking of the negative pressure and the positive pressure between the negative pressure input port94A, the positive pressure input port94B, and the output port is prevented.

Moreover, the friction force of the inner seal ring holds, in the negative or positive pressure supply position, the valve spool92that has moved thereto. Moreover, the rotary head50includes two V-axis drive devices100(an example of valve drive units) for moving the valve spool92of each switching device90between the negative pressure supply position201and the positive pressure supply position202along the Z-axis direction (the up-and-down direction), as illustrated inFIGS. 2 to 4. The two V-axis drive devices100have the same structure as each other, and are symmetrically disposed on both of the left and right sides of the rotary head50with respect to the shaft portion62of the rotating body60(refer toFIG. 5).

Moreover, the two V-axis drive devices100are provided, corresponding respectively to the Z-axis drive devices80, and are disposed immediately below their corresponding Z-axis drive devices80(refer toFIGS. 5 and 13). In other words, the V-axis drive device100and the Z-axis drive device80corresponding to the V-axis drive device100overlap each other when viewed from the direction of the rotation axis of the rotating body60.

As illustrated inFIGS. 3 to 5, the V-axis drive device100includes a box-shaped V-axis drive source102, and a V-axis moving portion104extending upward from the V-axis drive source102. A V-axis linear motor35V (refer toFIG. 7) for driving the V-axis moving portion104by linear motor drive is provided in the V-axis drive source102. The V-axis moving portion104is supported in such a manner as to be movable with respect to the V-axis drive source102in a direction along the shaft portion62, and is raised and lowered by the V-axis drive source102in the direction along the shaft portion62. In the embodiment, the V-axis linear motor35V is also an opposed moving magnet linear motor with a core.

As illustrated inFIGS. 4 and 5, the cam follower106(hereinafter referred to as the “V-axis cam follower106”) is attached to an upper end portion of the V-axis moving portion104of the V-axis drive device100in such a manner as to be rotatable about the axis along the X-axis direction. The V-axis moving portion104is supported by the V-axis drive source102in a placement where the V-axis cam follower106is located between the pair of opposed portions93A of the contact portion of the valve spool corresponding to the nozzle shaft in the drive position.

When the V-axis drive source102moves the V-axis moving portion104up, the V-axis cam follower106comes into contact with the pair of opposed portions93A located on both sides of the V-axis cam follower106, presses the valve spool92upward, and raises the valve spool92to the negative pressure supply position201. On the other hand, when the V-axis drive source102moves the V-axis moving portion104down, the V-axis cam follower106comes into contact with the pair of opposed portions93A located on both sides of the V-axis cam follower106, presses the valve spool92downward, and lowers the valve spool92to the positive pressure supply position202.

Here, the rotation axis of the V-axis cam follower106is along the X-axis direction. Accordingly, the rotation direction of the V-axis cam follower106substantially agrees with a tangent direction of a trajectory drawing the circumference of the circle of each nozzle shaft55rotated by the rotating body60. Hence, when the rotating body60is rotated during the raising and lowering operation of the valve spool92by the V-axis cam follower106, the V-axis cam follower106is rotated by the friction force between the pair of opposed portions93A while staying in contact with the pair of opposed portions93A. Accordingly, the raising and lowering operation of the valve spool92can be performed while each nozzle shaft55is rotated.

Moreover, the V-axis cam follower106is designed not to be in contact with both of the opposed portions93A of the valve spool92while the valve spool92is located close to a height position at the midpoint between the negative pressure supply position201and the positive pressure supply position202. Hence, the V-axis moving portion104can rotate the rotating body60without the V-axis cam follower106interfering with the valve spool92, while the valve spool92is close to the height position at the midpoint between the negative pressure supply position201and the positive pressure supply position202.

The rotary head50is provided with a board recognition camera C1(refer toFIG. 7). The board recognition camera C1moves integrally with the rotary head50to capture an image in any position on the printed board B1that has stopped in the operation position. Moreover, a component recognition camera C2(refer toFIG. 1) is fixed close to the operation position on the base10. The component recognition camera C2captures an image of the electronic component E1adhered by the suction nozzle56in the component supply position of the component feeding device40.

(3) Electrical Configuration of Surface-Mount Placement Machine

Next, the electrical configuration of the surface mounter1is described with reference toFIG. 7. A control unit110integrally controls the entire main body of the surface mounter1. The control unit110includes an operation control unit111configured of, for example, a CPU. The operation control unit111is connected to a motor controller112, a memory113, an image processor114, an external input/output portion115, a feeder communication portion116, a display117, and an input portion118.

In accordance with a mounting program113A described below, the motor controller112drives the X-axis servo motor35X and the Y-axis servo motor35Y of the component mounting device30, and drives the N-shaft servo motor35N, the R-shaft servo motor35R, the Z-axis linear motor35Z, and the V-axis linear motor35V of the rotary head50. Moreover, the motor controller112drives the transfer conveyor20in accordance with the mounting program113A.

The memory113is configured including a ROM (Read Only Memory) where, for example, a program that controls the CPU is stored, and a RAM (Random Access Memory) where various pieces of data are temporarily stored during the operation of the device. The mounting program113A and various pieces of data113B, which are described below, are stored in the memory113.

Specifically, the mounting program113A stored in the memory113includes board information related to the number of the printed boards B1manufactured and targeted for mounting, component information including the number and types of the electronic components E1to be mounted onto the printed board B1, and mounting information related to positions where the electronic components E1are mounted on the printed board B1. The various pieces of data113B stored in the memory113include data related to the number and type of the electronic components E1held by each feeder42of the component feeding device40.

The image processor114is designed to capture imaging signals outputted from the board recognition camera C1and the component recognition camera C2. The image processor114is designed to carry out an analysis of a component image and an analysis of a board image, respectively, on the basis of the imaging signals captured by the cameras C1and C2.

The external input/output portion115is what is called an interface, and is configured in such a manner as to capture detection signals outputted from a group of various sensors115A provided to the main body of the surface mounter1. Moreover, the external input/output portion115is configured in such a manner as to control operation over a group of various actuators115B on the basis of control signals outputted from the arithmetic processor111.

The feeder communication portion116is connected to a control unit of each feeder42attached to the component feeding device40, and integrally controls each feeder42. The control unit of each feeder42controls the drive of a motor for delivering the component supply tape.

The display117is configured including a liquid crystal display device with a display screen, and displays, for example, the state of the surface mounter1on the display screen. The input portion118is configured including a keyboard, and is designed to accept an input from the outside by a manual operation.

In the surface mounter1configured as described above, a transfer state where the transfer conveyor20performs the operation of transferring the printed board B1, and a mounting state where the operation of placing the electronic components E1onto the printed board B1carried in to the operation position on the base10is performed are alternately executed during automatic operation.

(4) Drive Mechanism of Linear Motor Drive in Z-Axis Drive Device

Next, a drive mechanism of linear motor drive in the Z-axis drive device80is described with reference toFIGS. 8 to 10.

As illustrated inFIG. 8, the box-shaped Z-axis drive source82includes a plate-shaped Z-axis main body portion142provided with a drive mechanism by linear motor drive, and a Z-axis cover143that is attached to the Z-axis main body portion142to protect the drive mechanism from the outside. The Z-axis cover143does not cover the Z-axis main body portion142completely, and is provided at the front with a cooling opening143A for preventing heat from becoming trapped in the Z-axis drive source82.

As illustrated inFIG. 9, in the Z-axis drive device80, the Z-axis drive source82is provided with a stator150of the linear motor, and the Z-axis moving portion84is provided with a mover160of the linear motor. The Z-axis drive source82is provided on the plate surface of the Z-axis main body portion142with the stator150including six armature coils152arranged side by side along a travel direction of the Z-axis moving portion84(the Z-axis direction and the up-and-down direction), and two rail guides154extending along the travel direction of the Z-axis moving portion84.

The stator150is provided on the front side (the left side inFIG. 9) of the Z-axis drive source82. The rail guide154is provided on the rear side of the Z-axis drive source82, and is provided on an inner side thereof with a rail groove (not illustrated) extending along an extension direction of the rail guide154.

On the other hand, as illustrated inFIG. 9, the Z-axis moving portion84includes a thick plate-shaped yoke162(an example of output shaft) orienting both plate surfaces in the front-and-rear direction and extending in the Z-axis direction, the mover160provided on the front surface of the yoke162and including a plurality of permanent magnets164(the reference numeral of them, apart from one, is omitted inFIG. 9), a rail168provided on the rear surface of the yoke162, and a cam follower support portion169attached to a lower end portion of the yoke162.

The yoke162is provided, at a lower end portion on a side opposite to the stator150across the yoke162, with a first to-be-read member163extending substantially parallel to the yoke162. As illustrated inFIG. 9, in the embodiment, the first to-be-read member163is formed in a U shape having a portion extending substantially parallel to the yoke162. An unillustrated scale for optically detecting the vertical position of the yoke162, that is, the vertical position of the mover160is marked on a surface163A, which faces the rear side, of the first to-be-read member163.

The plurality of permanent magnets164configuring the mover160is arranged side by side in a straight line at regular intervals such that different magnetic poles are alternately arranged. Here, inFIG. 9, a direction A indicates the direction in which the stator150and the mover160are arranged.

The rail168is provided in a groove form along an extension direction of the yoke162, and is fitted to the rail guide154via a plurality of balls provided in the groove in such a manner as to be movable along the extension direction of the yoke162(the travel direction of the Z-axis moving portion84, the Z-axis direction, and the up-and-down direction). The cam follower support portion169is provided to the lower end portion of the yoke162, and supports the Z-axis cam follower86rotatably. When the yoke162moves, the cam follower support portion169and the Z-axis cam follower86move together with the yoke162.

An encoder unit170(an example of a first position detection unit) faces the first to-be-read member163provided to the yoke162from the rear side. The encoder unit170optically reads the scale marked on the surface163A, which faces the rear side, of the first to-be-read member163to detect the vertical position of the mover160.

In the Z-axis drive device80, the Z-axis drive source82and the Z-axis moving portion84are configured as described above. Accordingly, when the armature coils152of the stator150are energized, the propulsive force of the linear motor drive, acts between the stator150and the mover160. The propulsive force moves the Z-axis moving portion84in the Z-axis direction (the up-and-down direction). The stator150and the mover160apply such propulsive force. The stator150and the mover160are set as the Z-axis linear motor35Z and controlled by the control unit110.

Next, the placement of the two Z-axis drive devices80is described more specifically with reference toFIG. 10. Here, a point61indicates the rotation axis of the rotating body60inFIG. 10. Moreover, the circle66indicated by a dotted line inFIG. 10indicates the virtual circle where the suction nozzles56are arranged. Moreover, each of two positions300A and300B illustrated inFIG. 10indicates a drive position where the Z-axis drive device80drives the nozzle shaft55(that is, the suction nozzle56). As described above, the two Z-axis drive devices80have the same structure as each other, and are disposed in such a manner as to be point-symmetric about the rotation axis61of the rotating body60when viewed from the direction of the rotation axis61. In other words, one of the Z-axis drive devices80is disposed in a form where the other of the Z-axis drive devices80has been rotated 180 degrees about the rotation axis61.

As illustrated inFIG. 10, the Z-axis drive devices80are disposed around the rotating body60when viewed from the direction of the rotation axis61of the rotating body60. The Z-axis drive devices80are disposed on a virtual straight line63orthogonal to the rotation axis61in an orientation where the mover16moves in the direction of the rotation axis61, and in an orientation where the stator150and the mover160are arranged in a tangent direction (the direction A illustrated inFIGS. 9 and 10) to the virtual circle66at a point of intersection of the virtual circle66where the suction nozzles56are arranged and the virtual straight line63.

(5) Drive Mechanism of Linear Motor Drive in V-Axis Drive Device

Next, a drive mechanism of linear motor drive in the V-axis drive device100is described with reference toFIGS. 11 to 13.

As illustrated inFIG. 11, the box-shaped V-axis drive source102includes a plate-shaped V-axis main body portion112provided with a drive mechanism of linear motor drive, and a V-axis cover114attached to the V-axis main body portion112to protect the drive mechanism from the outside. The V-axis cover114does not cover the V-axis main body portion112completely, and is provided at the front with a cooling opening114A for preventing heat from becoming trapped in the V-axis drive source102.

As illustrated inFIG. 12, in the V-axis drive device100, the V-axis drive source102is provided with a stator120of a linear motor, and the V-axis moving portion104is provided with a mover130of the linear motor. The V-axis drive source102is provided on the plate surface of the V-axis main body portion112with the stator120including three armature coils122arranged side by side along a travel direction of the V-axis moving portion104(the Z-axis direction and the up-and-down direction), a rail guide124extending along the travel direction of the V-axis moving portion104, and an iron piece (an example of a magnetic substance)126.

The stator120is provided on the front side (the left side inFIG. 12) of the V-axis drive source102. The rail guide124is provided on the rear side of the V-axis drive source102. The rail guide124is provided on an inner side thereof with a rail groove (not illustrated) extending along an extension direction of the rail guide124. The iron piece126is provided below the stator120, spaced a predetermined distance from the stator120.

On the other hand, as illustrated inFIG. 12, the V-axis moving portion104includes a thick plate-shaped yoke132(an example of output shaft) orienting both plate surfaces in the front-and-rear direction and extending in a travel direction of the V-axis drive source102, the mover130provided on the front surface of the yoke132and having a plurality of permanent magnets134, a position holding magnet136provided on the front surface of the yoke132and having one permanent magnet, a rail guide138provided on the rear surface of the yoke132, and a cam follower support portion139attached to an upper end portion of the yoke132.

A lower end portion of the yoke132is folded to a side opposite to the stator120to be provided integrally with a second to-be-read member133. An unillustrated scale for optically detecting the vertical position of the yoke132, that is, the vertical position of the mover130is marked on a surface133A, which faces the rear side, of the second to-be-read member133.

The plurality of permanent magnets134configuring the mover130is arranged side by side in a straight line at regular intervals such that different magnetic poles are alternately arranged. Here, inFIG. 12, a direction B indicates the direction in which the stator120and the mover130are arranged.

The position holding magnet136is provided on the front surface of a lower end portion of the yoke132and below the plurality of permanent magnets134configuring the mover130. The surface of the plurality of permanent magnets134and the surface of the position holding magnet136are located on the same plane.

The rail138is provided in a groove form along an extension direction of the yoke132, and is fitted to the rail guide124in such a manner as to be movable along the extension direction of the yoke132(the travel direction of the V-axis moving portion104, the Z-axis direction, and the up-and-down direction). The cam follower support portion139is provided to the upper end portion of the yoke132to rotatably support the V-axis cam follower106. When the yoke132moves, the cam follower support portion139and the V-axis cam follower106move together with the yoke132.

An encoder unit171(an example of a second position detection unit) faces the second to-be-read member133, which is the folded portion of the yoke132, from the rear side. The encoder unit171optically reads the scale marked on the surface133A, which faces the rear side, of the second to-be-read member133to detect the vertical position of the mover130.

In the V-axis drive device100, the rail guide124of the V-axis moving portion104is fitted to the rail guide138while the plurality of permanent magnets134and the stator120, and the position holding magnet136and the iron piece126are close to each other. The distance between the plurality of permanent magnets134and the stator120is substantially equal to the distance between the position holding magnet136and the iron piece126. On the other hand, as illustrated inFIG. 12, a distance D1between the position holding magnet136and the plurality of permanent magnets134configuring the mover130is set larger than a distance D2between the permanent magnets134included in the mover130.

In the V-axis drive device100, the V-axis drive source102and the V-axis moving portion104are configured as described above. Accordingly, when the armature coils122of the stator120are energized, the propulsive force of the linear motor drive acts between the stator120and the mover130. The propulsive force moves the V-axis moving portion104in the Z-axis direction (the up-and-down direction). The stator120and the mover130, which apply such propulsive force, are set as the V-axis linear motor35V, and are controlled by the control unit110.

On the other hand, in the V-axis drive device100, when the energization of the armature coils122of the stator120is stopped, a magnetic force acting between the position holding magnet136and the iron piece126holds the V-axis moving portion104in a height position in the Z-axis direction (the up-and-down direction) at the midpoint between the position where the valve spool92is in the negative pressure supply position201and the position where the valve spool92is in the positive pressure supply position202. In other words, the position holding magnet136and the iron piece126function as what is called a magnetic spring.

The magnetic force of the plurality of permanent magnets134configuring the mover130is set larger than the magnetic force of the position holding magnet136. It is configured such that the position holding magnet136does not influence the travel of the V-axis drive source102by the linear motor drive.

Next, the placement of the two V-axis drive devices100is described more specifically with reference toFIG. 13. Here, the point61indicates the rotation axis of the rotating body60inFIG. 13. Each of two positions301A and301B illustrated inFIG. 13indicates the drive position where the V-axis drive device100drives the valve spool92(that is, the valve). As described above, the two V-axis drive devices100have the same structure as each other, and are disposed in such a manner as to be point-symmetric about the rotation axis61of the rotating body60. In other words, one of the V-axis drive devices100is disposed in the form where the other of the V-axis drive devices100has been rotated 180 degrees about the rotation axis61.

As illustrated inFIG. 13, the V-axis drive devices100are disposed around the rotating body60when viewed from the direction of the rotation axis61of the rotating body60. The V-axis drive devices100are disposed on a virtual straight line64orthogonal to the rotation axis61in an orientation where the mover130moves in the direction of the rotation axis61, and in an orientation where the stator120and the mover130are arranged in a tangent direction (the direction B illustrated inFIGS. 12 and 13) to the virtual circle66at a point of intersection of the virtual circle66where the suction nozzles56are arranged and the virtual straight line64.

(6) Effects of Embodiment

According to the rotary head50of the embodiment described above, the Z-axis drive device80includes the opposed linear motor with the core as the drive source. The opposed linear motor with the core has a higher thrust density than the linear shaft motor. Accordingly, when the motor is of the same size, even if its operating load is increased, heat is unlikely to be generated. Hence, according to the rotary head50, it is possible to prevent a reduction in the precision of placement due to heat generated by the linear motor.

Furthermore, according to the rotary head50, the Z-axis drive device80is disposed around the rotating body60in the orientation where the mover160moves in the direction of the rotation axis61. Accordingly, it is possible to prevent the Z-axis drive device80from extending out in a direction of the virtual straight line63as compared to, for example, a case where the Z-axis drive device80is disposed in an orientation where the mover160moves in the direction of the virtual straight line63. Furthermore, according to the rotary head50, the Z-axis drive device80is disposed on any virtual straight line (in the embodiment the virtual straight line63) orthogonal to the rotation axis61of the rotating body60in the orientation where the stator150and the mover160are arranged in the tangent direction to the virtual circle66at the point of intersection of the virtual circle66and the virtual straight line63. Accordingly, it is possible to further prevent the Z-axis drive device80from extending out in the direction of the virtual straight line63as compared to a case where the Z-axis drive device80is disposed in an orientation where the stator150and the mover160are inclined against the tangent direction (for example, a case where the Z-axis drive device80is disposed in an orientation where the stator150and the mover160are arranged in the direction of the virtual straight line63).

In this manner, according to the rotary head50, it is possible to prevent the Z-axis drive device80from extending out. Accordingly, as illustrated inFIG. 10, a circle (outermost circle)65circumscribing the Z-axis drive device80with the rotation axis61of the rotating body60as the center can be reduced. In other words, the rotary head50can be made compact when viewed from the direction of the rotation axis61of the rotating body60. Consequently, it is possible to cause the rotary head50to have a large range of motion in a direction perpendicular to the rotation axis61of the rotating body60.

Furthermore, according to the rotary head50, the first to-be-read member163extending substantially parallel to the yoke162is provided to the yoke162(an example of the output shaft) on the side opposite to the stator150across the yoke162. For example, the yoke162is formed in a straight shape extending straight in the direction of the rotation axis61of the rotating body60, and the extension portion is used as the to-be-read member. Accordingly, it is also possible to dispose the stator150and the encoder unit170, side by side, in the direction of the rotation axis61. However, in this case, the yoke162is increased in length in the direction of the rotation axis61. Accordingly, it may be difficult to secure a space for disposing the Z-axis drive device80.

Contrarily, according to the rotary head50, the first to-be-read member163extending substantially parallel to the yoke162is provided on the side opposite to the stator150across the yoke162. Accordingly, the length of the yoke162in the direction of the rotation axis61can be reduced. Consequently, it is easy to secure the space for disposing the Z-axis drive device80, even if it is difficult to secure the space for disposing the Z-axis drive device80when the yoke162is long in the direction of the rotation axis61.

Furthermore, according to the rotary head50, the V-axis drive device100includes the opposed linear motor with the core as the drive source, and accordingly is unlikely to generate heat even if a high operating load is applied thereto. Hence, according to the rotary head50, it is possible to prevent a reduction in the precision of placement due to heat generated by the linear motor.

Furthermore, according to the rotary head50, the V-axis drive device100is disposed around the rotating body60on the virtual straight line64orthogonal to the rotation axis61in the orientation where the mover130moves in the direction of the rotation axis61, and in the orientation where the stator120and the mover130are arranged in the tangent direction (the direction B illustrated inFIGS. 12 and 13) to the virtual circle66at the point of intersection of the virtual circle66and the virtual straight line64. Accordingly, the rotary head50can be made compact when viewed from the direction of the rotation axis61of the rotating body60. Consequently, it is possible to cause the rotary head50to have a large range of motion in the direction perpendicular to the rotation axis61of the rotating body60.

Furthermore, according to the rotary head50, the Z-axis drive device80and the V-axis drive device100overlap each other when viewed from the direction of the rotation axis61of the rotating body60. If the Z-axis drive device80and the V-axis drive device100extend out in different directions when viewed from the direction of the rotation axis61of the rotating body60, the rotary head50results in being increased in size when viewed from the direction of the rotation axis61of the rotating body60.

Contrarily, according to the rotary head50, the Z-axis drive device80and the V-axis drive device100overlap each other when viewed from the direction of the rotation axis61of the rotating body60. Accordingly, the direction in which the Z-axis drive device80extends out is substantially the same as the direction in which the V-axis drive device100extends out. Hence, the rotary head50can be reduced in size when viewed from the direction of the rotation axis61as compared to the case where they extend out in directions different from each other. Consequently, it is possible to cause the rotary head50to have a large range of motion in the direction perpendicular to the rotation axis61.

Furthermore, according to the rotary head50, the second to-be-read member133extending substantially parallel to the yoke132(an example of the output shaft) is provided to the yoke132on the side opposite to the stator120across the yoke132. Accordingly, it is easy to secure a space for disposing the V-axis drive device100, even if it is difficult to secure the space for disposing the V-axis drive device100when the yoke132is long in the direction of the rotation axis61.

OTHER EMBODIMENTS

The technology disclosed in the description is not limited to the embodiment described above with the drawings, and includes, for example, the following embodiments in the technical scope.

(1) In the above embodiment, the description has been given taking, as an example, the case where two Z-axis drive devices80and two V-axis drive devices100are included. However, these numbers are not limited to two, and may be three or more.

(2) In the above embodiment, the description has been given, taking, as an example, the case where two Z-axis drive devices80are included, and are disposed in such a manner as to be point-symmetric about the rotation axis61of the rotating body60when viewed from the direction of the rotation axis61. Contrarily, the two Z-axis drive devices80may not be necessarily disposed in such a manner as to be point-symmetric.

(3) In the above embodiment, the description has been given, taking, as an example, the case where two pairs of the Z-axis drive device80and the V-axis drive device100are included, and in both pairs, the V-axis drive device100is located immediately below the Z-axis drive device80corresponding to the V-axis drive device100(the Z-axis drive device80and the V-axis drive device100corresponding to the Z-axis drive device80overlap each other when viewed from the direction of the rotation axis61of the rotating body60). Contrarily, in both pairs, the V-axis drive device100may not be located immediately below the Z-axis drive device80, or only in one of the pairs, the V-axis drive device100may be located immediately below the Z-axis drive device80.

(4) In the above embodiment, the description has been given, taking, as an example, the case where the Z-axis drive device80includes the opposed linear motor with the core. However, if the V-axis drive device100includes the opposed linear motor with the core, the Z-axis drive device80may not include the opposed linear motor with the core. For example, if the V-axis drive device100includes the opposed linear motor with the core, the Z-axis drive device80may move the suction valve56by a linear motor other than the opposed linear motor with the core, or by a rotary motor.

(5) In the above embodiment, the description has been given, taking, as an example, the case where the V-axis drive device100includes the opposed linear motor with the core. However, if the Z-axis drive device80includes the opposed linear motor with the core, the V-axis drive device100may not include the opposed linear motor with the core. For example, if the Z-axis drive device80includes the opposed linear motor with the core, the V-axis drive device100may move the suction valve56by a linear motor other than the opposed linear motor with the core, by a rotary motor, by a solenoid valve, or by pneumatic pressure.

(6) In the above embodiment, the description has been given, taking the suction nozzle as the component holding member as an example. However, the component holding member is not limited to the suction nozzle. For example, the component holding member may be what is called a chuck that sandwiches and holds a component between two claws.