JP2005347310A - Electronic component mounting equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress vibration and deformation of a stator when a shaft motor type linear motor is used for movement of a transfer head. Provide electronic component mounting equipment.
A transfer head 12 for transferring an electronic component, an X-axis linear motor 7 that holds the transfer head 12 and moves it in the X-axis direction, supports the X-axis linear motor 7, and extends in the X-axis direction. Electronic component mounting apparatus 1 comprising an X-axis beam member 6 and a Y-axis linear motor 3 that moves the transfer head 12 together with the X-axis beam member 6 in the Y-axis direction perpendicular to the movement direction of the X-axis linear motor 7. The X-axis linear motor 7 includes a shaft-like stator 7a extending in the X-axis direction and supported at both ends by the X-axis beam member 6, and surrounding the stator 7a provided on the transfer head 12, and And a tension applying means for applying tension to the stator 7a.
[Selection] Figure 2

Description

  The present invention relates to an electronic component mounting apparatus for transporting and mounting a supplied electronic component to a predetermined position on an electronic substrate using a transfer head.

  In the electronic component mounting apparatus, a transfer head that transports an electronic component moves in the horizontal direction by a motor related to movement of the X axis and a motor related to movement of the Y axis. In recent years, a linear motor is used for moving the transfer head and the setting accuracy of the transfer head is improved. In this case, the mover of the linear motor is provided in the transfer head, and the stator is supported by the beam member extending in the moving direction. As a linear motor used in an electronic component mounting apparatus, a coreless type in which a yoke is not arranged on the mover (for example, refer to Patent Document 1), and a type with a core in which a yoke is arranged on the mover (for example, Patent Document 2) is known.

  When a coreless type linear motor is used, there is no suction force between the mover and stator, making it easy to assemble them, and the load applied to the linear guide that holds the mover and guides it in the axial direction is compared. Therefore, there is an advantage that a large rigidity is not required for the linear guide. However, since the yoke does not exist in the mover, the driving efficiency is poor, and a relatively large current flows through the coil of the mover, and the amount of heat generated by the mover increases. Therefore, there is a problem that the component parts of the apparatus are deformed by the heat generated in the mover and the setting accuracy of the transfer head is lowered.

On the other hand, when a linear motor with a core is used, the mover has a yoke, so the drive efficiency is good, and the amount of heat generated by the mover is suppressed to prevent thermal deformation of each component of the device. Can do. However, the suction force with the stator acts on the movable element, and the weight of the movable element increases because the yoke is arranged on the movable element. Therefore, the linear guide is required to have a large rigidity, and the linear guide is firmly configured. Need arises.
JP 2001-309634 A JP 2001-512627 A

  In order to solve the above problems, it is conceivable to employ a shaft motor type linear motor. In the shaft motor type, since the shaft-shaped stator is surrounded by the mover, it is possible to suppress the heat generation amount of the mover by using the magnetic field generated by the stator without waste while taking advantage of the coreless type.

  However, since the mover surrounds the shaft-like stator and moves along the stator, the stator cannot be supported within the moving range of the mover. Therefore, the long stator is supported by the beam members at both ends thereof, which causes a problem that the bending rigidity of the stator is lowered. That is, the stator vibrates when acceleration is applied in a direction perpendicular to the beam member, such as moving the transfer head in the X-axis direction by the mover and moving the transfer head together with the beam member in the Y-axis direction. However, there is a risk of deformation and interference with the mover. Further, since the stator vibrates, not only the followability in the movement control of the transfer head is deteriorated, but also the settling time of the transfer head becomes longer and the settling accuracy is deteriorated.

  The present invention has been made in view of the above circumstances, and its object is to suppress vibration and deformation of the stator when a shaft motor type linear motor is used for movement of the transfer head. It is an object to provide an electronic component mounting apparatus capable of performing the above.

  In order to achieve the above object, according to the first aspect of the present invention, there is provided a transfer head for transferring an electronic component, a linear motor for holding the transfer head and moving it in a predetermined axial direction, and the linear motor. An electronic component mounting apparatus comprising: a beam member that supports and extends in the axial direction; and a beam moving device that moves the transfer head together with the beam member in an axial direction perpendicular to a moving direction of the linear motor. The motor extends in the axial direction and has a shaft-like stator that is supported at both ends by the beam member, a movable element that is provided in the transfer head, surrounds the stator and moves along the stator, And a tension applying means for applying tension to the stator.

According to the first aspect of the present invention, the transfer head is moved in the predetermined axial direction by the linear motor and the axial direction perpendicular to the moving direction when transporting the supplied electronic component to the electronic substrate. The beam member is moved by the beam moving device.
Here, tension is applied to the stator by the tension applying means, and the natural frequency of the stator is increased. That is, since the shaft-shaped stator has a high natural frequency, the amount of deformation during vibration is small, and as a result, dynamic rigidity is improved. As a result, when the beam moving device is driven, acceleration in a direction perpendicular to the axial direction acts on the long stator, but vibration is suppressed because the dynamic rigidity of the stator is improved. Even if it vibrates, the amount of deformation is small.

  According to a second aspect of the present invention, in the electronic component mounting apparatus according to the first aspect, the tension applying unit is configured to apply tension to the stator when acceleration is applied to the beam member by driving the beam moving device. It is characterized by giving.

  According to the second aspect of the present invention, in addition to the action of the first aspect, when the acceleration is generated in the beam member and the stator is deformed in the bending direction, tension is applied to the stator. No tension is applied to the stator until no additional force is applied.

  According to a third aspect of the present invention, in the electronic component mounting apparatus according to the first or second aspect, the tension applying unit may be configured so that the stator member is in accordance with an acceleration generated in the beam member by driving the beam moving device. It is characterized by varying the tension.

  According to the third aspect of the invention, in addition to the action of the first or second aspect, tension is applied to the stator in accordance with the acceleration generated in the beam member, so that the texture corresponding to the rigidity required for the stator is obtained. Fine tensioning control is realized.

  According to a fourth aspect of the present invention, in the electronic component mounting apparatus according to any one of the first to third aspects, the electronic component mounting apparatus includes a stress detection unit that detects a stress of the stator, and the tension applying unit includes the stress applying unit. A tension is applied to the stator in accordance with the stress detected by the detecting means.

According to the invention described in claim 4, in addition to the action of any one of claims 1 to 3, tension is applied in accordance with the stress of the stator detected by the stress detection means. Fine tension control corresponding to the required rigidity is realized. In addition, since the stress of the stator is directly detected, for example, the weight of the transfer head changes due to replacement of the suction nozzle, and the weight of the transfer head changes depending on whether the electronic component is loaded or not. Even when the weight of the transfer head changes depending on the type of electronic component to be conveyed and the stress applied to the stator changes, it is possible to accurately apply tension to the stator correspondingly.
Further, for example, when the tension applied to the stator is changed from an expected value due to aging deterioration, the stress applied to the stator is changed. Therefore, it is possible to accurately apply tension to the stator in response to stress changes due to aging.

  According to a fifth aspect of the present invention, in the electronic component mounting apparatus according to any one of the first to third aspects, the stress detection means for detecting the stress of the stator, and the stress detected by the stress detection means Stress information display means for displaying information based on the above.

According to the fifth aspect of the invention, in addition to the action of any one of the first to third aspects, information based on the stress of the stator detected by the stress detection means is displayed by the stress information display means. Therefore, the operator can confirm the information based on the stress. As a result, for example, the weight of the transfer head changes due to the replacement of the suction nozzle, the weight of the transfer head changes depending on whether the electronic component is loaded or not, and the transfer depends on the type of electronic component to be transferred Even when the weight of the head changes and the stress applied to the stator changes, the operator can adjust the tension applied to the stator correspondingly.
In addition, for example, when the tension applied to the stator is changed from an expected value due to aging, or when the tension applying means does not operate normally, the stress applied to the stator changes. Therefore, the operator can apply a tension applied to the stator corresponding to the aging deterioration, and can recognize a failure of the apparatus.

  According to a sixth aspect of the present invention, in the electronic component mounting apparatus according to any one of the first to fifth aspects, a correction rod whose both ends are supported on the opposite side of the axial center of the beam member, Tension correction means for applying tension to the correction rod according to the tension applied to the stator by the tension application means is provided.

  According to the invention described in claim 6, in addition to the operation of any one of claims 1 to 5, when tension is applied to the stator by the tension applying means, tension is applied to the correction rod by the tension correcting means. Is done. At this time, the bending force applied from the stator and the bending force applied from the correction rod are applied to the beam member. Here, since the correction rod is arranged on the opposite side with respect to the stator and the axial center, the bending force from the stator and the bending force applied from the correction rod cancel each other in the beam member.

According to the first aspect of the present invention, when a shaft motor type linear motor is used for the movement of the transfer head, even if acceleration in a direction perpendicular to the axial direction acts on the long stator, it is fixed. The vibration and deformation of the child can be suppressed. Further, since a linear motor of the shaft motor type is used, the linear guide for guiding the mover can be made simple, and the amount of heat generated by the mover is suppressed by using the magnetic field generated by the stator without waste. be able to.
As a result, the settling of the linear motor itself is improved, and the upper limit of the acceleration of the beam member by driving the beam moving device in which the stator and the mover of the linear motor do not interfere with each other increases, thereby improving the settling of the beam moving device. To do. Accordingly, the movement time of the transfer head when the electronic component is conveyed is shortened, the settling time after the movement is shortened, and the stop accuracy of the transfer head is improved. That is, it is possible to improve the mounting tact and mounting accuracy of electronic components on the electronic substrate.

  According to the second aspect of the present invention, in addition to the effect of the first aspect, no tension is applied to the stator until the load in the bending direction is not applied, and the load applied to the stator is minimized. It is possible to suppress the occurrence of permanent distortion in the stator.

  According to the third aspect of the invention, in addition to the effect of the first or second aspect, fine tension applying control corresponding to the rigidity required for the stator is realized, and the stator can be stably controlled. Can do.

According to the invention described in claim 4, in addition to the effect of any one of claims 1 to 3, fine tension control corresponding to the rigidity required for the stator is realized, and the stator is stabilized. Can be controlled. Further, since the stress of the stator is directly detected, even when the stress applied to the stator changes, it is possible to accurately apply tension to the stator corresponding to this.
In addition, no tension is applied to the stator until no load in the bending direction is applied, the load applied to the stator can be minimized, and the occurrence of permanent distortion in the stator can be suppressed. it can.

According to invention of Claim 5, in addition to the effect of any one of Claims 1 to 3,
The operator can grasp information based on the stress of the stator and adjust the tension applied to the stator corresponding to the change in the stress applied to the stator.

  According to the sixth aspect of the present invention, the bending force from the stator and the bending force applied from the correction rod cancel each other in the beam member. Can be suppressed, the shape accuracy of the beam member can be maintained, and the rigidity, strength, and reliability durability can be improved.

  1 to 5 show a first embodiment of the present invention, FIG. 1 is an external perspective view of an electronic component mounting apparatus, and FIG. 2 is an exploded view of an electronic component mounting apparatus in which a part of a transfer head is disassembled. 3 is an exploded perspective view, FIG. 3 is a schematic view of an X-axis linear motor, FIG. 4 is a longitudinal sectional view of an X-axis beam member and an X-axis linear motor, and FIG. 5 is a transverse sectional view of the X-axis beam member and the X-axis linear motor. is there. 1 and 2 schematically show an X-axis linear motor, a Y-axis linear motor, and the like.

  As shown in FIG. 1, the electronic component mounting apparatus 100 includes an X-axis linear motor 7 that moves the transfer head 12 to the X-axis, and a transfer head 12 that moves the Y-axis above the base 1 that has a substantially rectangular parallelepiped shape. A Y-axis linear motor 3 or the like that is moved to is placed. The electronic component mounting apparatus 100 transports and mounts the electronic component supplied from the parts feeder 13 to the electronic substrate 10 positioned on the transport path 9 that is placed on the transfer head 12 and extends in the X-axis direction.

  As shown in FIG. 1, Y-axis fixed tables 2 extending in the Y-axis direction along the periphery of the base 1 are provided at both ends in the X-axis direction on the upper surface of the base 1. A stator 3 a of the Y-axis linear motor 3 is provided on the outer surface of each Y-axis fixed table 2. A rail 4 a of the Y-axis linear guide 4 is fixed to the upper surface of each Y-axis fixing table 2.

  As shown in FIG. 1, each Y-axis linear motor 3 has a mover 3b arranged with a predetermined gap from a stator 3a. In the present embodiment, each stator 3a is a shaft whose both ends are supported by the Y-axis fixed table 2, and each movable element 3b has a substantially rectangular parallelepiped shape having a coil inside and surrounding the stator 3a. Thereby, the mover 3b is movable in the Y-axis direction along the stator 3a.

  The mover 3 b is engaged with the lower surface of the Y-axis moving table 5. Further, the slider 4b of the Y-axis linear guide 4 is engaged with the lower surface of each Y-axis moving table 5 adjacent to the mover 3b. Here, the slider 4b is guided in the Y-axis direction by the rail 4a. Thereby, each Y-axis moving table 5 is movable in the Y-axis direction along the rail 4 b of the Y-axis linear guide 4 and is driven by the Y-axis linear motor 3.

  As shown in FIG. 2, an X-axis beam member 6 is installed on each Y-axis moving table 5. The X-axis beam member 6 extends in the X-axis direction across the base 1 and has a substantially U-shaped cross section that is concave with respect to one of the Y-axes. That is, in this embodiment, the Y-axis linear motor 3 serves as a beam moving means for moving the transfer head 12 together with the X-axis beam member 6 in an axial direction perpendicular to the moving direction of the X-axis linear motor 7. A stator 7 a of the X-axis linear motor 7 is provided in the concave portion of the X-axis beam member 6. The rails 8a of the X-axis linear guide 8 are fixed to the upper and lower protruding portions of the X-axis beam member 6, respectively.

  As shown in FIG. 2, the X-axis linear motor 7 has a mover 7b arranged with a predetermined gap from a stator 7a. In the present embodiment, the stator 7a is a shaft whose both ends are supported by the X-axis beam member 6, and the movable element 7b has a substantially rectangular parallelepiped shape having a coil inside and surrounding the stator 7a. Thereby, the mover 7b is movable in the X-axis direction along the stator 7a.

  The mover 7 b is engaged with the front surface of the X-axis moving table 11. A slider 8b of each X-axis linear guide 8 is engaged with the front surface of the X-axis moving table 11 adjacent to the mover 8b. Here, each slider 8b is guided in the X-axis direction by the rail 8a. Thus, the X-axis moving table 11 is movable in the X-axis direction along the rail 8 b of the X-axis linear guide 8 and is driven by the X-axis linear motor 7.

Here, the mover 7b of the X-axis linear motor 7 and the stator 7a of the X-axis linear motor 7 will be described in detail.
As shown in FIG. 3, the stator 7 a is a shaft that is arranged in a plurality so that the same poles of the permanent magnets 15... Face each other, and the periphery thereof is covered with a yoke that is a nonmagnetic material.
The mover 7b is a slider arranged so that the three-phase coil C circulates around the shaft-like stator 7a as a whole.
That is, the X-axis linear motor 7 is a drive motor called a shaft motor.

  The stator 7a has a length (height) of about 60 mm to 120 mm, and includes a plurality of cylindrical permanent magnets 15 with one end face being an N pole and the other end face being an S pole. The N poles and the S poles are arranged so as to face each other. Each permanent magnet 15 is repelled, but is forced into a single bar shape. By covering this rod with a yoke and forming it as a shaft, a linear motor stator 7a is formed. In this shaft, the magnetic lines of force emerge from the portion where the N and N poles face each other and go to the portion where the S and S poles face each other.

A mover 7b, which is a slider, is disposed so as to surround the outer peripheral surface of the stator 7a, which is the shaft. The mover 7b is separately provided with an X-axis linear guide 8, and is arranged so that the stator 7a and the mover 7b do not contact each other.
On the mover 7b, about one to four sets of three-phase coils C are arranged in the axial direction of the shaft in the direction in which the coils are wound around the stator 7a. The length of each coil (the axial length of the shaft) is the same as the pitch of the shaft magnets, that is, 60 mm to 120 mm. One coil crosses the magnetic flux generated from either the N pole or the S pole. When a current is passed through this, a shaft motor that operates as a synchronous motor is obtained. As the X-axis linear motor 7 operates, the movable element 7b moves so as to slide in the X-axis direction along the stator 7a, and as a result, the transfer head 12 moves in the X-axis direction.

  As described above, a plurality of X-axis linear motors 7 of the electronic component mounting apparatus 1 according to the present invention are arranged so that the same poles of the magnets face each other, and a shaft whose periphery is covered with a yoke that is a nonmagnetic material is fixed. Since this is a shaft motor having a movable element 7b which is a slider arranged so that a three-phase coil C circulates around the shaft, the configuration of the X-axis linear motor 7 can be simplified and assembled. Can be improved. Moreover, the smooth operation in the electronic component mounting apparatus 1 can be enabled.

  A plurality of transfer heads 12 that adsorb electronic components are provided adjacent to the back surface of the X-axis moving table 11. That is, in the present embodiment, the X-axis linear motor 7 holds the transfer head 12 and moves it in a predetermined axial direction. Although not particularly shown, each transfer head 12 has an air suction-type suction nozzle, a Z-axis motor that moves the suction nozzle in the Z-axis direction, and the suction nozzle in the XY plane around the Z-axis. And a θ-axis motor that is rotated by the motor.

  Next, the fixed state of the stator 7a of the X-axis linear motor 7 in the X beam member 6 will be described in detail. As shown in FIG. 4, the stator 7 a of the linear motor 7 includes a pipe 14 made of a carbon composite material extending in the X-axis direction, and a plurality of ring-shaped permanent magnets arranged inside the pipe 14 and arranged in the X-axis direction. A magnet 15 and a center shaft 16 extending in the X-axis direction inside each permanent magnet 15 are included.

  As shown in FIG. 4, a bracket 17 is provided on one end side of the stator 7 a so as to be screwed with the pipe 14 and the center shaft 16. The bracket 17 has a substantially cylindrical shape, and a step portion is formed on the peripheral surface so as to descend toward the other end side in the axial direction. In the present embodiment, as shown in FIG. 5, male screw portions are formed on the outer surface of one end side of the pipe 14 and one end side of the center shaft 16, and are respectively screwed with the female screw portions formed on the bracket 17. It has become. The bracket 17 is held by a ring-shaped motor holder 18a abutted against the stepped portion. Thereby, the bracket 17 is locked to the motor holder 18a, and the movement of the stator 7a to the other end side in the axial direction is restricted. As shown in FIG. 4, the motor holder 18a is provided with a tightening screw 18a1 for adjusting the tightening degree with respect to the bracket 17.

  A cap 19 that is screwed into the pipe 14 is provided on the other end side of the stator 7a. The cap 19 has a substantially cylindrical shape and has a rod-shaped portion 19 a that protrudes to the opposite side of the pipe 14. In the present embodiment, as shown in FIG. 5, a female screw portion is formed on the inner surface of the other end side of the pipe 14 and is screwed with a male screw portion formed on the peripheral surface of the cap 19. The cap 19 is held by a ring-shaped motor holder 18b. The motor holder 18b is not abutted against the step portion like the motor holder 18a on one end side, and the axial movement of the stator 7a is allowed. As shown in FIG. 4, the motor holder 18b is provided with a tightening screw 18b1 for adjusting the tightening degree with respect to the cap 19. Further, a male screw portion is formed on the other end side of the center shaft 16, and the permanent magnets 15 are brought into close contact with each other by tightening a nut 20 screwed into the male screw portion. As shown in FIG. 4, the motor holders 18 a and 18 b are fixed to the X-axis beam member 6 by bolts 21 and 22.

  The rod-like portion 19 a of the cap 19 passes through the hole of the motor pull angle 23 and is screwed with the pull nut 24 on the other end side of the motor pull angle 23. As shown in FIG. 5, the motor pull angle 23 is formed in a substantially L shape in a top view, and is inserted through the rod-like portion 19 a and perpendicular to the X axis, and from one end of the insertion plate portion 23 a. And a fixed plate portion 23b extending along the X-axis beam member 6 toward the other end in the axial direction. The motor pull angle 23 is fixed to the X-axis beam member 6 by a bolt 25 inserted through the fixed plate portion 23b.

  Thereby, when the pull nut 24 is tightened, the rod-shaped portion 19a of the cap 19 is pulled toward the other end in the axial direction, and the stator 7a is pulled as a whole toward the other end. As described above, the movement of the bracket 17 toward the other end in the axial direction is restricted by the motor holder 18a on one end side of the stator 7a. Therefore, by adjusting the tightening degree of the pull nut 24, the stator 7a The tension of can be adjusted. The motor holder 18a on one axial end side is positioned with the X-axis beam member 6 by the pin 26a and the motor pull angle 23 by the pin 26b. As a result, the motor holder 18 and the motor pull angle 23 at one end in the axial direction are not displaced with respect to the X-axis beam member 6 when the pull nut 24 is tightened.

  A method for assembling the X-axis beam member 6 and the X-axis linear motor 7 of the electronic component mounting apparatus 1 configured as described above will be described. Note that the pipe 14, the permanent magnets 15, the center shaft 16, the bracket 17, and the cap 19 of the stator 7a are in a state of being assembled with each other in advance.

  The operator first engages the motor holders 18 a and 18 b with the X-axis beam member 6, and fixes the motor holders 18 a and 18 b to the X-axis beam member 6 using the bolts 21 and 22. Next, the operator inserts the stator 7a from the cap 19 side into the motor holder 18a on one end side, and abuts the stepped portion of the bracket 17 against the motor holder 18a. Then, in this state, the operator tightens the fastening screw 18a1 of the motor holder 18a, and causes the motor holder 18a to hold one end side of the stator 7a.

  Further, the operator inserts the cap 19 of the stator 7 a into the motor holder 18 b on the other end side, and inserts the rod-shaped portion 19 a of the cap 19 into the motor pull angle 23. Then, the motor pull angle 23 is fixed to the X-axis beam member 6 with a bolt 25. Thereafter, the operator causes the pull nut 24 to be screwed with the rod-shaped portion 19a, and the pull nut 24 is lightly turned by hand to contact the motor pull angle 23. Subsequently, the operator further tightens the pull nut 24 using a tool for a predetermined number of rotations. With the tension applied to the stator 7a in this way, the fastening screw 18b1 of the motor holder 18b is tightened, and the other end side of the stator 7a is held by the motor holder 18b.

Next, the operation of the control system when mounting the electronic component on the electronic substrate 10 in the electronic component mounting apparatus 1 configured as described above will be described.
First, the electronic substrate 10 is carried from outside the apparatus through the conveyance path 9 and fixed at a predetermined mounting position. Subsequently, by driving the X-axis linear motor 7 and the Y-axis linear motor 3, the transfer head 12 is moved to above the parts feeder 13, and electronic components are picked up by the respective suction nozzles based on production data stored in advance. Suck and hold sequentially.

  Thereafter, the X-axis linear motor 7 and the Y-axis linear motor 3 are driven to move the transfer head 12 to an electronic component mounting position above the electronic substrate 10 and to provide an electronic component (not shown) provided on the transfer head 12. The attitude of the electronic component sucked and held by the attitude detection device is detected. Then, the XY axes of the respective suction nozzles are positioned and the suction nozzles are rotated by the θ-axis motor to correct the component postures, and then the electronic components are sequentially mounted on the electronic board 10.

  When the mounting operation of all the suction nozzles holding the electronic components is completed, the parts feeder 13 for supplying the electronic components for mounting the transfer head 12 next time by driving the X-axis linear motor 7 and the Y-axis linear motor 3 again. Move to above. By repeating these operations, a plurality of electronic components are mounted on the electronic substrate 10.

  In this series of operations, the X-axis linear motor 7 and the transfer head 12 are moved together with the X-axis beam member 6 by the Y-axis linear motor 3 when moving the electronic component in the Y-axis direction. Here, tension is applied to the stator 7a by tension applying means including a motor pull angle 23, a pull nut 24, etc., and the natural frequency of the stator 7a is increased. That is, since the shaft-shaped stator 7a has a high natural frequency, the amount of deformation during vibration is small, and as a result, dynamic rigidity is improved. As a result, when the Y-axis linear motor 3 is driven, acceleration in a direction perpendicular to the axial direction acts on the long stator 7a, but the dynamic rigidity of the stator 7a is improved. Vibration can be suppressed, and even if it vibrates, the amount of deformation is small.

  Thus, according to the electronic component mounting apparatus 100 of the present embodiment, a shaft motor type linear motor is used to move the transfer head 12, and the long stator 7a is in the Y-axis direction perpendicular to the X-axis direction. Even if this acceleration acts, the vibration and deformation of the stator 7a can be suppressed. Further, since a shaft motor type linear motor is used for driving the X axis, the X axis linear guide 8 for guiding the mover 7b can be made simple, and the magnetic field generated by the stator 7a can be used without waste. Thus, the amount of heat generated by the mover 7b can be suppressed.

  As a result, the settling of the X-axis linear motor 7 itself is improved, and the upper limit of the acceleration of the Y-axis linear motor 3 where the stator 7a and the mover 7b of the X-axis linear motor 7 do not interfere with each other increases. The settling of the motor 3 is also improved. Therefore, the movement time of the transfer head 12 when the electronic component is conveyed is shortened, the settling time after the movement is shortened, and the stopping accuracy of the transfer head 12 is improved. That is, it is possible to improve the mounting tact and mounting accuracy of electronic components on the electronic substrate.

Further, according to the electronic component mounting apparatus 100 of the present embodiment, the tensile stress due to the tightening of the nut 20 is acting on the center shaft 16, but the tensile stress is applied to the pipe 14 without the tensile stress acting on the center shaft 16. Therefore, excessive tensile stress is not generated in the center shaft 16 and the center shaft 16 is not plastically deformed or broken, which is extremely advantageous in practical use.
In addition, since the pipe 14 is made of a carbon composite material that is relatively strong against a load in the pulling direction and is relatively lightweight, the weight of the apparatus can be reduced while maintaining the strength of the pipe 14.

  In the above embodiment, the pull nut 24 applies tension to the stator 7a. However, as shown in FIG. 6, for example, pull bolt 27 may apply tension to the stator 7a. In this case, the cap 19 is not formed with the rod-shaped portion 19a through which the motor pull angle 23 is inserted, but the cap 19 is formed with an internal thread portion, and a pull bolt 27 through which the motor pull angle 23 is inserted is screwed. In this case, the pull bolt 27, the motor pull angle 23, and the like serve as tension applying means. Also with this configuration, the tension of the stator 7a can be adjusted by the tightening degree of the pull bolt 27, and the same effect as the above embodiment can be obtained.

  Further, for example, as shown in FIG. 7, a step portion symmetrical to the bracket 17 is formed on the peripheral surface of the cap 19, the motor holder 18b is butted against this step portion, and tension is applied to the stator 7a by the motor holder 18b. You may do it. In FIG. 7, the adjustment screw 28 that is screwed with the motor holder 18 b is configured to abut against the protruding portion 6 a of the X-axis beam member 6. In this case, the protrusion 6a, the adjustment screw 28, and the like serve as tension applying means. Even in this configuration, the tension of the stator 7 a can be adjusted by the tightening degree of the adjusting screw 28.

Further, as shown in FIG. 8, the X-axis beam member 6 includes a correction rod 29 that is supported at both ends on the opposite side of the center of the stator 7a, and is corrected according to the tension applied to the stator 7a by the pull nut 24. A tension may be applied to the rod 29. The tension correction means for applying tension to the correction rod 29 at this time may have the same configuration as that of the X-axis beam member 6, or may use an electrostrictive element or the like, for example.
With such a configuration, a force in the bending direction from the stator 7 a and a force in the bending direction from the correction rod 29 are applied to the X-axis beam member 6. Here, since the correction rod 29 is disposed on the opposite side of the axial center with respect to the stator 7 a, the bending force from the stator 7 a and the bending force applied from the correction rod 29 in the X-axis beam member 6. Are offset. Therefore, the internal stress of the X-axis beam member 6 can be reduced to suppress bending deformation, and the rigidity, strength, and reliability durability of the X-axis beam member 6 can be improved.

  FIGS. 9 and 10 show a second embodiment of the present invention. FIG. 9 is a cross-sectional view of the X-axis beam member and the X-axis linear motor, and FIG. 10 is a schematic block diagram of the tension control unit. In the second embodiment, tension is applied to the stator 7 a by the electrostrictive element 30, and the stress of the stator 7 a is detected by the piezoelectric element 31.

  In the second embodiment, the motor holder 18b on the other end side is positioned on the X-axis beam member 6 by the pin 26b. As shown in FIG. 9, a step portion symmetrical to the bracket 17 is formed on the peripheral surface of the cap 19, and the electrostrictive element 30 and the piezoelectric element 31 are interposed between the step portion and the motor holder 18b. Has been. Since other configurations are substantially the same as those of the first embodiment, description thereof is omitted here.

  In the present embodiment, the electrostrictive element 30 and the piezoelectric element 31 are each formed in a ring shape and surround the cap 19 in a state of being adjacent to each other. The electrostrictive element 30 and the piezoelectric element 31 are electrically connected to the tension control unit 40, respectively. The electrostrictive element 30 serving as a tension applying means extends in the X-axis direction when a voltage is applied to apply tension to the stator 7a. Further, the piezoelectric element 31 as the stress detecting means outputs a current when a pressure is applied to detect a stress generated in the stator 7a.

  As illustrated in FIG. 10, the tension control unit 40 includes a microcomputer in which a CPU 41, a ROM 42, a RAM 43, and an I / O interface 44 are connected to each other via a bus line 45. To the I / O interface 44, the Y-axis linear motor 3, the X-axis linear motor 7, the electrostrictive element 30, the piezoelectric element 31, and the like are connected.

  The ROM 102 stores a tension adjustment program 110 that adjusts the tension of the stator 7a. The tension adjustment program 110 is set so as to apply tension to the stator 7 a in accordance with the stress detected by the piezoelectric element 31. In the present embodiment, the tension applied to the stator 7a is set to increase by increasing the current applied to the electrostrictive element 30 in proportion to the detected stress.

  Even in this electronic component mounting apparatus, when a shaft motor type linear motor is used to move the transfer head 12, even if acceleration in a direction perpendicular to the axial direction acts on the long stator 7a, the stator The vibration and deformation of 7a can be suppressed.

In addition, since tension is applied in accordance with the stress of the stator 7a detected by the electrostrictive element 30, fine tension control corresponding to the rigidity required for the stator 7a is realized. Further, since the stress of the stator 7a is directly detected, for example, the weight of the transfer head changes due to replacement of the suction nozzle, or the weight of the transfer head 12 changes depending on whether the electronic component is loaded or not. In addition, even when the weight of the transfer head 12 changes depending on the type of electronic components to be conveyed and the stress applied to the stator 7a changes, the tension should be applied to the stator 7a accurately corresponding to this. Can do.
In addition, for example, when the tension applied to the stator 7a changes from an expected value due to aging, the stress applied to the stator 7a changes. Accordingly, it is possible to accurately apply tension to the stator 7a in response to a stress change due to aging deterioration.

  Therefore, no tension is applied to the stator 7a until no load in the bending direction is applied, and the load applied to the stator 7a can be minimized, and the occurrence of permanent distortion in the stator 7a is suppressed. can do. Further, fine tension control corresponding to the rigidity required for the stator 7a is realized, and the stator can be stably controlled.

  In the second embodiment, the stress detecting unit detects the stress by the piezoelectric element 31. However, the stress may be detected by a strain gauge. Furthermore, the stress may be detected indirectly by detecting the amount of deformation of the stator 7a and converting it to stress. In this case, a configuration using an optical fiber sensor or the like is preferable for detecting the deformation amount of the stator 7a.

In the second embodiment, the tension is applied to the stator 7a based on the stress of the stator 7a. However, acceleration is applied to the X-axis beam member 6 by driving the Y-axis linear motor 3. Sometimes, tension may be applied to the stator 7a. That is, it is only necessary to monitor the driving state of the Y-axis linear motor 3 and apply tension to the stator 7a. In this case, since the tension is applied to the stator 7a when the X-axis beam member 6 is accelerated and the stator 7a is deformed in the bending direction, the tension is applied to the stator 7a until no load is applied in the bending direction. Will not be granted.
Further, it is preferable that the tension of the stator 7a is changed in accordance with the acceleration generated in the X-axis beam member 6 by driving the Y-axis linear motor 3. In this case, since tension is applied to the stator 7a according to the acceleration generated in the X-axis beam member 6, fine tension control corresponding to the rigidity required for the stator 7a is realized.

Further, in the second embodiment, the tension is applied to the stator 7a corresponding to the detected stress. However, the information based on the detected stress is displayed on the display unit as the stress information display means. You may make it display. Thereby, the operator can confirm the information based on stress. In this case, it is preferable that the operator adjusts the tension to the stator 7a as in the first embodiment. By adopting such a configuration, for example, the weight of the transfer head can be increased by replacing the suction nozzle. The stress applied to the stator 7a changes due to changes, the weight of the transfer head 12 changes depending on whether the electronic component is loaded or not, and the weight of the transfer head 12 changes depending on the type of electronic component to be conveyed. Even when the angle changes, the operator can adjust the tension applied to the stator 7a correspondingly.
Further, for example, when the tension applied to the stator 7a is changed from an expected value due to aging, or when the tension applying means does not operate normally, the stress applied to the stator 7a changes. Therefore, the operator can apply the tension applied to the stator 7a corresponding to the aging deterioration, and can recognize the failure of the apparatus.

  Also in the second embodiment, the X-axis beam member 6 includes a correction rod that is supported at both ends on the opposite side of the center of the stator 7a and according to the tension applied to the stator 7a by the electrostrictive element 30. In addition, a tension correction unit such as an electrostrictive element that applies tension to the correction rod may be provided.

  Furthermore, in the first and second embodiments, the present invention is applied to the stator 7a of the X-axis linear motor 7 of the transfer head 12, but the Z-axis linear motor stator of the transfer head 12 is shown. The present invention can also be applied to. In this case, when the transfer head 12 moves about the XY plane by the Y-axis linear motor 3 and the X-axis linear motor 7, tension is applied to the stator of the Z-axis linear motor.

  In the above-described embodiment, the shaft motor type linear motor is used as the beam member moving means for moving the X-axis beam member 6 in the Y-axis direction. Of course, other specific detailed structures can be changed as appropriate.

1 is an external perspective view of an electronic component mounting apparatus showing a first embodiment of the present invention. It is a partial exploded perspective view of the electronic component mounting apparatus in a state where a part of the transfer head is disassembled. It is a partial exploded perspective view of the electronic component mounting apparatus in a state where a part of the transfer head is disassembled. It is a longitudinal cross-sectional view of an X-axis beam member and an X-axis linear motor. It is a cross-sectional view of an X-axis beam member and an X-axis linear motor. It is a cross-sectional view of the X-axis beam member and X-axis linear motor which show the modification of 1st Embodiment. It is a cross-sectional view of the X-axis beam member and X-axis linear motor which show the modification of 1st Embodiment. It is a general view of the X-axis beam member and X-axis linear motor which show the modification of 1st Embodiment. It is a cross-sectional view of an X-axis beam member and an X-axis linear motor showing a second embodiment. It is a schematic block diagram of a tension control unit.

Explanation of symbols

3 Y-axis linear motor 6 X-axis beam member 7 X-axis linear motor 7a Stator 7b Movable element 12 Transfer head 23 Motor pull angle 24 Pull nut 27 Pull bolt 28 Adjustment screw 29 Correction rod 30 Electrostrictive element 31 Piezoelectric element 40 Tension control unit 100 Electronic component mounting device

Claims (6)

A transfer head for transferring electronic components;
A linear motor that holds the transfer head and moves it in a predetermined axial direction;
A beam member that supports the linear motor and extends in the axial direction;
In an electronic component mounting apparatus comprising: a beam moving device that moves the transfer head together with the beam member in an axial direction perpendicular to a moving direction of the linear motor;
The linear motor is
A shaft-like stator extending in the axial direction and supported at both ends by the beam member;
A mover that is provided in the transfer head and surrounds the stator and moves along the stator;
An electronic component mounting apparatus comprising tension applying means for applying tension to the stator.   The electronic component mounting apparatus according to claim 1, wherein the tension applying unit applies tension to the stator when acceleration is generated in the beam member by driving the beam moving device.   The electronic component mounting apparatus according to claim 1, wherein the tension applying unit varies the tension of the stator in accordance with an acceleration generated in the beam member by driving the beam moving device. A stress detecting means for detecting the stress of the stator;
4. The electronic component mounting apparatus according to claim 1, wherein the tension applying unit applies a tension to the stator corresponding to the stress detected by the stress detecting unit. 5. . Stress detecting means for detecting the stress of the stator;
The electronic component mounting apparatus according to claim 1, further comprising: a stress information display unit that displays information based on the stress detected by the stress detection unit. Correction rods whose both ends are supported on the opposite side of the axial center of the stator in the beam member;
6. The electron according to claim 1, further comprising a tension correction unit that applies tension to the correction rod in accordance with a tension applied to the stator by the tension application unit. Component mounting equipment.

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