Patent Publication Number: US-2020282567-A1

Title: Robot apparatus for soldering

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a robot apparatus that performs soldering. 
     2. Description of the Related Art 
     The processes for manufacturing products include a process for securing parts by soldering. For example, electronic components are secured to a printed board by soldering, and are connected to an electric circuit formed on the printed board. In the prior arts, a spot soldering device that solders small areas of a workpiece one by one is known (for example, Japanese Unexamined Patent Publication No. 2005-167142A). In the spot soldering device, a table that moves in the X-axis direction and the Y-axis direction is disposed, and the relative position of the solder pot with respect to the workpiece is changed so that a desired portion can be soldered. 
     In order to perform soldering, flux is applied to a portion to be soldered so as to remove oxides and improve wettability. Further, preheating for heating the board is performed. Thereafter, molten solder is supplied to a portion to be soldered in order to perform soldering. 
     In the prior arts, a soldering device that performs a process of supplying solder to a board as well as a process of applying flux and a process of preheating for heating the board (for example, Japanese Patent No. 2761204B, Japanese Unexamined Patent Publication No. 11-298134A, and Japanese Patent No. 4414642B). 
     SUMMARY OF THE INVENTION 
     In spot soldering devices commercially available, a flux applying process, a board preheating process, and a solder supplying process are performed by different devices. Thus, in order to perform each process, it is necessary to convey a board between the devices. However, components that are not soldered may fall over or tilt with respect to the board while the workpiece is being conveyed. Further, in order to shift one process to another process, there is the problem that a complicated device for conveying the board is necessary. 
     Further, in the conventional spot soldering devices capable of performing the flux applying process, the preheating process, and the solder supplying process, devices for performing respective processes are arranged on the lower side. Further, the board moves above each device. In such a structure, there is the problem that the size of the soldering device tends to be increased, since the devices for performing the respective processes are formed separately. Thus, in order to arrange the soldering device, it is necessary to secure a large space. 
     A robot apparatus according to a first aspect of this disclosure includes a robot having a plurality of joints and operation tools each of which is connected to the robot. The robot apparatus includes a solder pot having a container for melting and storing solder and a nozzle from which the solder is flowed out. The robot apparatus includes a table that is disposed above the robot and supports a workpiece, and a placement member on which the operation tools and the solder pot can be placed. The robot apparatus includes a controller for controlling the robot. The operation tools include a flux ejection tool that ejects soldering flux, and a support tool that supports the solder pot. The robot has a function of automatically replacing operation tools. The operation tools and the solder pot are placed on the placement member. The controller performs a flux application control for coupling the flux ejection tool to the robot and applying flux to a portion to be soldered of the workpiece. The controller performs a preheating control for coupling the support tool to the robot and arranging the solder pot below the workpiece so as to heat the workpiece by the heat released from the solder pot. The controller performs a supply control for moving the nozzle of the solder pot closer to the workpiece so as to supply solder to a portion of the workpiece to be soldered. 
     A robot apparatus according to a second aspect of this disclosure includes a robot having a plurality of joints and operation tools each of which is connected to the robot. The robot apparatus includes a solder pot having a container for melting and storing solder and a nozzle from which the solder flows out. The robot apparatus includes a table that is disposed above the robot and supports a workpiece, and a placement member on which the operation tools and the solder pot can be placed. The robot apparatus includes a controller that controls the robot. The operation tools includes a flux ejection tool that ejects soldering flux, a preheating tool having a heater the temperature of which can be increased, and a support tool that supports the solder pot. The robot has a function of automatically replacing operation tools. The operation tools and the solder pot are placed on the placement member. The controller performs a flux application control for coupling the flux ejection tool to the robot and applying the flux to a portion to be soldered of the workpiece. The controller performs a preheating control for coupling the preheating tool to the robot and moving the preheating tool closer to the workpiece so as to heat the workpiece. The controller performs a supply control for coupling the support tool to the robot and moving the nozzle of the solder pot closer to the workpiece so as to supply solder to a portion of the workpiece to be soldered. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a robot apparatus according to an embodiment. 
         FIG. 2  is a perspective view of a robot according to the embodiment. 
         FIG. 3  is a perspective view of a table and a table drive motor according to the embodiment. 
         FIG. 4  is an enlarged perspective view of a support member that supports the table according to the embodiment. 
         FIG. 5  is a perspective view of a placement member and components placed on the placement member according to the embodiment. 
         FIG. 6  is a perspective view of a flux ejection tool according to the embodiment. 
         FIG. 7  is a perspective view of a support tool for supporting the solder pot according to the embodiment. 
         FIG. 8  is a perspective view of the solder pot before being supported by the support tool. 
         FIG. 9  is a perspective view of the solder pot after being supported by the support tool. 
         FIG. 10  is a first perspective view of the solder pot according to the embodiment. 
         FIG. 11  is a second perspective view of the solder pot. 
         FIG. 12  is a third perspective view of the solder pot. 
         FIG. 13  is a fourth perspective view of the solder pot. 
         FIG. 14  is a block diagram of the robot apparatus according to the embodiment. 
         FIG. 15  is a perspective view of the robot apparatus for explaining a first process of soldering according to the embodiment. 
         FIG. 16  is a perspective view of the robot apparatus for explaining a second process of soldering. 
         FIG. 17  is an enlarged perspective view of components placed on the placement member and the robot for explaining a third process of soldering. 
         FIG. 18  is an enlarged perspective view of the robot apparatus for explaining a fourth process of soldering. 
         FIG. 19  is a perspective view of the robot apparatus for explaining a fifth process of soldering. 
         FIG. 20  is an enlarged perspective view of the robot apparatus for explaining a sixth process of soldering. 
         FIG. 21  is an enlarged perspective view of the robot apparatus for explaining a seventh process of soldering. 
         FIG. 22  is an enlarged perspective view of the robot apparatus for explaining an eighth process of soldering. 
         FIG. 23  is an enlarged perspective view of the robot apparatus for explaining a ninth process of soldering. 
         FIG. 24  is an enlarged perspective view of the solder pot and the support tool for explaining a first process in an operation of replacing a nozzle of the solder pot according to the embodiment. 
         FIG. 25  is an enlarged perspective view of the solder pot and the support tool for explaining a second process in the operation of replacing the nozzle of the solder pot. 
         FIG. 26  is an enlarged perspective view of the solder pot and the support tool for explaining a third process in the operation of replacing the nozzle of the solder pot. 
         FIG. 27  is an enlarged perspective view of the solder pot and the support tool for explaining a fourth process in the operation of replacing the nozzle of the solder pot. 
         FIG. 28  is an enlarged perspective view of the solder pot and the support tool for explaining a fifth process in the operation of replacing the nozzle of the solder pot. 
         FIG. 29  is an enlarged perspective view of the support tool and solder bars for explaining a first process in an operation of replenishing the solder pot with solder. 
         FIG. 30  is an enlarged perspective view of the solder pot and the solder bar grasped by the support tool for explaining a second process in the operation of replenishing the solder pot with solder. 
         FIG. 31  is an enlarged perspective view of another flux ejection tool according to the embodiment. 
         FIG. 32  is a perspective view of a preheating tool according to the embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     A robot apparatus according to an embodiment will be described with reference to  FIGS. 1 to 32 . The robot apparatus of the present embodiment performs a soldering operation in order to secure an electronic component to a printed board as a workpiece. The robot apparatus of the present embodiment performs an operation of applying flux, an operation of heating the printed board, and an operation of supplying solder by changing an operation tool so as to secure a component to the printed board. 
       FIG. 1  is a perspective view of the robot apparatus according to the present embodiment. The robot apparatus  5  of the present embodiment is a spot soldering device that performs soldering in a predetermined partial area of a workpiece. The robot apparatus  5  includes an operation tool as an end effector and a robot  1  that moves the operation tool. The robot apparatus  5  includes a solder pot  7  having a nozzle  31   a  from which the solder is flowed out toward the workpiece. The operation tools of the present embodiment include a flux ejection tool  2  for applying flux to a printed board and a support tool  3  for supporting the solder pot  7  for supplying solder to the printed board. The flux ejection tool  2  has a function of ejecting soldering flux. 
       FIG. 2  is a perspective view of a robot of the present embodiment. The robot  1  of the present embodiment is an articulated robot including a plurality of joints. The robot  1  includes a base  14  and a turning base  13  supported by the base  14 . The base  14  is secured to a frame body  26  via a panel  27 . The turning base  13  is formed so as to rotate with respect to the base  14 . The robot  1  includes an upper arm  11  and a lower arm  12 . The lower arm  12  is rotatably supported by the turning base  13  via a joint. The upper arm  11  is rotatably supported by the lower arm  12  via a joint. Further, the upper arm  11  rotates around a rotation axis parallel to the extending direction of the upper arm  11 . 
     The robot  1  includes a wrist  15  coupled to an end of the upper arm  11 . The wrist  15  is rotatably supported by the upper arm  11  via a joint. The wrist  15  includes a flange  16  that is rotatably formed. The operation tool is secured to the flange  16 . The robot  1  of the present embodiment has six drive axes, but is not limited to this configuration. Any robot that can change the position and the orientation of the operation tool can be adopted. 
     Referring to  FIG. 1 , the robot apparatus  5  includes the frame body  26  that supports the devices and components constituting the robot apparatus  5 , and a placement member  28  supported by the frame body  26 . The panel  27  is disposed around the frame body  26 . The placement member  28  is disposed on the side of the robot  1 . The placement member  28  is formed so that the flux ejection tool  2 , the support tool  3 , and the solder pot  7  can be placed thereon. 
     In the present embodiment, the side indicated by arrow  91 , on which the placement member  28  is disposed, is referred to as the front side of the robot apparatus  5 . The placement member  28  is disposed at the front side of the robot  1 . The placement member  28  is disposed within a range in which the robot  1  can operate the components placed on the placement member  28 . For example, the placement member  28  is disposed at a position where the robot  1  can replace the operation tool placed on the placement member  28 . 
     The robot apparatus  5  includes a robot controller  4  as a controller for controlling the robot  1 . The robot controller  4  controls the flux ejection tool  2  and the support tool  3 . Further, the robot controller  4  controls a table drive motor  20  for driving a table  6 . 
     The robot apparatus  5  includes a flux supply device  58  for supplying pressurized flux to the flux ejection tool  2 . The flux supply device  58  has a tank for storing flux and a pump for pressurizing the flux. The flux supply device  58  is controlled by the robot controller  4 . The flux pressurized in the flux supply device  58  is supplied to the flux ejection tool  2  through a flux supply tube  57 . The flux supply device  58  is placed on the panel  27  disposed at the bottom of the frame body  26 . 
     The solder pot  7  is connected to the robot controller  4  via a cable  79 . The solder pot  7  is powered via the cable  79 . The solder pot  7  has a function of melting and storing the solder and discharging the solder from the nozzle  31   a.    
       FIG. 3  is an enlarged perspective view of the table and the table drive motor for driving the table according to the present embodiment. Referring to  FIGS. 1 and 3 , the robot apparatus  5  has the table  6  disposed above the robot  1 . The table  6  of the present embodiment is formed so as to have a circular planar shape. The table  6  supports printed boards  34   a  and  34   b  as workpieces. The table  6  has openings  6   a  and  6   b  in which the printed boards  34   a  and  34   b  are disposed. In the present embodiment, pallets  33  on which a plurality of printed boards  34   a  and  34   b  are placed are disposed in the openings  6   a  and  6   b . It should be noted that the table may be formed so that the workpieces are placed directly thereon without using the pallets. 
     The robot apparatus  5  includes a table drive device  38  for driving the table  6 . The table drive device  38  includes a table drive motor  20  for rotating the table  6 . The rotational force output by the table drive motor  20  is transmitted to the table  6  via a shaft  21 . The shaft  21  is connected to the center of the circular planar shape of the table  6 . The table drive motor  20  is driven so as to rotate the table  6  in the circumferential direction. It should be noted that the table drive device may be formed so as to rotate the table with air pressure. 
       FIG. 4  is an enlarged perspective view of a support member according to the present embodiment. Referring to  FIGS. 1, 3 and 4 , the table  6  is supported by a support member  29 . The support member  29  is secured to the frame body  26 . The support member  29  includes a roller  30   a  that supports the outer peripheral surface of the table  6  and a roller  30   b  that supports the bottom surface of the table  6 . The roller  30   a  restricts the movement of the table  6  in the radial direction. The roller  30   b  restricts the movement of the table  6  in the vertical direction. Moreover, the roller  30   b  suppresses bending of the table  6 . 
     Referring to  FIG. 1 , a plurality of support members  29  are arranged in the robot apparatus  5 . In the present embodiment, the support members  29  are arranged at four locations. Thus, it is possible to suppress the table  6  from moving in the radial direction or from bending by supporting the table  6  with the plurality of support members  29 . As a result, the position of the printed board supported by the table  6  can be prevented from deviating from a predetermined position. In the present embodiment, four support members are arranged, but the embodiment is not limited to this. Any number of support members can be arranged in order to support the table. 
       FIG. 5  is an enlarged perspective view of the placement member according to the present embodiment. The placement member  28  of the present embodiment is formed into a plate shape. The placement member  28  is secured to the frame body  26 . Referring to  FIGS. 1 and 5 , the placement member  28  is formed so as to extend in the horizontal direction. The solder bar  32 , the flux ejection tool  2 , the support tool  3 , and the solder pot  7  are placed on the placement member  28  of the present embodiment. Further, nozzles  31   b ,  31   c  and  31   d  with which the nozzle  31   a  of the solder pot  7  can be replaced are placed on the placement member  28 . 
     The placement member  28  has support pillars  28   a . Solder bars  32  for replenishing the solder pot  7  with solder are placed between a plurality of the support pillars  28   a . The solder bars  32  are arranged between the support pillars  28   a . The placement member  28  of the present embodiment is formed into a plate shape, but is not limited to this configuration. Any shape can be applied to the placement member if components such as an operation tool and a solder pot can be placed thereon. 
     The positions of the devices and members placed on the placement member  28  are predetermined. The robot  1  is driven to the position and posture set in an operation program  41  so as to operate the device and the member placed on the placement member  28 . 
     Referring to  FIG. 1 , plate-like panels  27  are disposed around the frame body  26 . An opening  27   a  through which an operator can check the internal state is formed in the panel  27  disposed on the front side of the frame body  26 . An exhaust cylinder  25  is connected to the panel  27  disposed on the upper portion of the frame body  26 . The exhaust cylinder  25  has a function of releasing, for example, vapor generated from the solder within the frame body  26  to the outside. It should be noted that the exhaust cylinder  25  may be connected to a duct for discharging the vapor to the outside of the building. 
     The devices and members, which constitute the robot apparatus  5  of the present embodiment, are disposed inside the frame body  26 . For example, the robot  1 , the placement member  28 , the table  6 , the table drive motor  20 , the flux supply device  58 , and the robot controller  4  are arranged inside the frame body  26 . 
     In  FIG. 2  and the subsequent figures, the panels  27  secured to the side portion and the upper portion of the frame body  26  are omitted. The panels  27  do not necessarily have to be arranged. Moreover, the panels  27  may be arranged on the side part, the upper part, and the lower part of the frame so as to seal the space inside the frame  26 . 
       FIG. 6  is an enlarged perspective view of the flux ejection tool in the present embodiment.  FIG. 6  shows that the flux ejection tool  2  is coupled to the flange  16  of the wrist  15  of the robot  1 . The robot apparatus  5  in the present embodiment has an automatic tool changer (ATC) that can automatically replace operation tools with one another. The automatic tool changer includes a robot-side plate  51  attached to the flange  16  of the robot  1  and a tool-side plate  52  attached to the operation tool. 
     The tool-side plate  52  is formed so as to be coupled to or released from the robot-side plate  51 . The automatic tool changer of the present embodiment is controlled by the robot controller  4 . The robot  1  changes its position and posture so as to couple the robot-side plate  51  to the tool-side plate  52  and support the operation tool. Thus, the robot  1  of the present embodiment has a function of automatically replacing operation tools including the flux ejection tool  2  and the support tool  3 . 
     The flux ejection tool  2  includes a base member  55  secured to the tool-side plate  52 . The base member  55  is formed into a plate shape. The flux ejection tool  2  has a nozzle  56  secured to the base member  55 . The nozzle  56  of the present embodiment is a spray nozzle. A flux supply tube  57  for supplying flux is connected to the nozzle  56 . A valve is disposed on the nozzle  56 . The valve is opened so as to eject the flux from the tip of the nozzle  56 . The nozzle  56  of the present embodiment is controlled by the robot controller  4 . 
       FIG. 7  is an enlarged perspective view of the support tool according to the present embodiment. The support tool  3  of the present embodiment includes a base member  61  that supports the solder pot  7  and a chuck part  62  attached to the base member  61 . The base member  61  is formed into an L shape when viewed from the side. A tool-side plate  53  of the automatic tool changer is secured to the base member  61  of the support tool  3 . Thus, the robot  1  can automatically couple and release the support tool  3 . 
     The chuck part  62  has two claws  64  that face each other. Further, the chuck part  62  has a cylinder  63  for opening and closing the claws  64 . The cylinder  63  is driven and thereby causes the claws  64  facing each other to move so as to grasp or release any component. 
       FIG. 8  is an enlarged perspective view of the support tool before supporting the solder pot according to the present embodiment. When the solder pot  7  is not used, the solder pot  7  is placed on the placement member  28  (see  FIG. 5 ). A notch is formed in the placement member  28 . The support tool  3  supports the bottom of the solder pot  7  through the notch. When supporting the solder pot  7 , the robot  1  raises the support tool  3  from below the solder pot  7  as indicated by arrow  92 . 
     The base member  61  of the support tool  3  has, on its surface contacting the bottom surface of the solder pot  7 , a plurality of protrusions  61   a . Recesses, each of which has a shape corresponding to the shape of the protrusion  61   a , are formed in the bottom surface of the container  71  of the solder pot  7 . The protrusions  61   a  of the base member  61  are fitted into the recesses of the container  71 , and thus the position of the solder pot  7  is determined with respect to the support tool  3 . Further, the protrusions  61   a  are fitted into the recesses of the solder pot  7 , and thus the solder pot  7  is prevented from moving with respect to the support tool  3 . 
       FIG. 9  is an enlarged perspective view of the support tool after supporting the solder pot according to the present embodiment. The base member  61  of the support tool  3  contacts the side surface and the bottom surface of the container  71  of the solder pot  7 . The solder pot  7  is heavy, due to molten solder being disposed therein. Thus, the protrusions  61   a  formed on the base member  61  of the support tool  3  are fitted into the recesses formed in the container  71  of the solder pot  7 , and thus the solder pot  7  can be reliably supported by the support tool  3 . 
     The solder pot in the present embodiment will now be described in detail.  FIG. 10  is a perspective view of the solder pot according to the present embodiment. The solder pot  7  has a container  71  that stores molten solder, and a lid member  72  that covers the upper opening of the container  71 . The container  71  is formed so as to have the nozzle  31   a  from which the solder flows out. In the present embodiment, the nozzle  31   a  is disposed so that the opening of the nozzle  31   a  faces upward. The solder pot  7  has a motor  73  for pressurizing the solder so as to discharge the solder from the nozzle  31   a.    
     The solder pot  7  in the present embodiment has a securing mechanism  80  that secures and releases the nozzle  31   a . The securing mechanism  80  of the solder pot  7  has a turning member  74  for securing the nozzle  31   a  to the solder pot  7 . The securing mechanism  80  includes a support member  75  for supporting the turning member  74 . The nozzle  31   a  has an engagement part  35  that engages with the turning member  74 . The turning member  74  is engaged with the engagement part  35 , and thus the nozzle  31   a  is secured to the solder pot  7 . 
     The solder pot  7  is formed so that a plurality of types of nozzles can be arranged thereon. For example, areas to be soldered may be small or large. Alternatively, the planar shapes of the areas to be soldered are different from one another in some cases. In such a case, spot soldering can be performed for areas having various shapes or sizes by replacing the nozzle  31   a  with another nozzle. 
     The lid member  72  of the solder pot  7  has a wall part  72   a  extending in the vertical direction. The wall part  72   a  is formed so as to surround the nozzle  31   a . Further, an opening which communicates with the inner space of the solder pot  7  is formed between the wall part  72   a  and the nozzle  31   a . A hole  72   b  which is shaped so that the solder bar can be inserted therein is formed in the lid member  72 . 
       FIG. 11  is a perspective view of the solder pot when the lid member is removed. The container  71  according to the present embodiment has an inner member  71   a  made of a metal such as stainless steel, and a heat insulating member  71   b  formed so as to cover the inner member  71   a . The heat insulating member  71   b  is made of a material such as ceramics or glass which is thermally resistant and has low thermal conductivity. The heat insulating member  71   b  is disposed so as to cover the entirety of the outer peripheral surface of the inner member  71   a . Further, the lid member  72  of the present embodiment has an inner member and a heat insulating member formed so as to cover the inner member in the same way as the container  71 . An electric heater as a heater is disposed on the back side of the bottom surface of the inner member  71   a . The electric heater is driven and thereby melts the solder disposed inside the inner member  71   a.    
     In the container  71  and the lid member  72  according to the present embodiment, the heat insulating member  71   b  is disposed so as to cover the outer surface thereof. This configuration enables the heat to be prevented from transferring from the solder pot  7 . The power consumption of the electric heater for melting the solder disposed inside the solder pot  7  can be reduced. 
       FIG. 12  is a perspective view of the solder pot when the motor is removed. Referring to  FIGS. 11 and 12 , a fitting member  76  into which the nozzle  31   a  is fitted is disposed inside the inner member  71   a . The fitting member  76  is formed so as to be fitted with the nozzle  31   a  when the nozzle  31   a  is inserted from above. The solder pot  7  includes an impeller  78  for pressurizing the molten solder. The molten solder is supplied to the nozzle  31   a  through the inner space of the fitting member  76  by the impeller  78  rotated by the motor  73 . Further, the molten is discharged from the tip of the nozzle  31   a.    
     Referring to  FIG. 10 , excessive solder which has been discharged from the nozzle  31   a  flows downward through the tubular member of the nozzle  31   a  as indicated by arrow  98 . Thereafter, the solder returns to the inside of the container  71  through the space between the nozzle  31   a  and the wall part  72   a.    
       FIG. 13  is a perspective view of the solder pot which stores therein the molten solder when the lid member is removed. The molten solder  83  is stored inside the inner member  71   a . Referring to  FIGS. 10 and 13 , the molten solder is exposed through the opening between the wall part  72   a  of the lid member  72  and the nozzle  31   a . Hot air rises from the space between the wall part  72   a  and the nozzle  31   a.    
       FIG. 14  is a block diagram of the robot apparatus according to the present embodiment. The robot  1  includes a robot drive device that changes the position and posture of the robot  1 . The robot drive device includes a plurality of robot drive motors  17  that drive components such as the arm and the wrist. The robot drive motors  17  are disposed for respective components. The orientation of each component is changed by the corresponding robot drive motor  17  that is driven. 
     The controller of the robot apparatus  5  includes a robot controller  4 . The robot controller  4  includes an arithmetic processing device (computer) having a CPU (Central Processing Unit) serving as a processor. The arithmetic processing unit includes, for example, a RAM (Random Access Memory) and a ROM (Read Only Memory), which are connected to the CPU via a bus. In order to control the robot apparatus  5 , an operation program  41  which has been previously made is input to the robot controller  4 . The robot controller  4  includes a storage unit  42  that stores information related to the control of the robot apparatus  5 . The storage unit  42  can be configured by a storage medium capable of storing information, such as a volatile memory, a nonvolatile memory, or a hard disk. The operation program  41  is stored in the storage unit  42 . The robot controller  4  of the present embodiment controls a soldering operation based on the operation program  41 . 
     The robot controller  4  includes an operation control unit  43  that sends an operation command. The operation control unit  43  corresponds to the processor that is driven according to the operation program  41 . The processor functions as the operation control unit  43 , i.e., reads the operation program  41  and performs a control defined in the operation program  41 . 
     The operation control unit  43  sends an operation command for driving the robot  1  to a robot drive unit  45  based on the operation program  41 . The robot drive unit  45  includes an electric circuit that drives the robot drive motors  17 . The robot drive unit  45  supplies electricity to the robot drive motors  17  based on the operation command. 
     Further, the operation control unit  43  sends an operation command for driving the operation tool to an operation tool drive unit  44  based on the operation program  41 . The operation tool drive unit  44  includes an electric circuit that drives the operation tool. The operation tool drive unit  44  supplies electricity to the valve of the flux ejection tool  2  based on the operation command. The operation tool drive unit  44  supplies electricity to a flux supply device  58  based on the operation command. The operation tool drive unit  44  supplies electricity to drive devices including an air pump and a valve for driving the chuck part  62  based on the operation command. 
     The operation control unit  43  sends an operation command for driving a table to a table drive unit  46  based on the operation program  41 . The table drive unit  46  includes an electric circuit for driving the table drive motor  20 . The table drive unit  46  supplies electricity to the table drive motor  20  based on the operation command. 
     The robot  1  includes a state detector for detecting the position and posture of the robot  1 . The state detectors in the present embodiment includes position detectors  18  which are attached to the robot drive motors  17  corresponding to the drive axes of the components such as an arm, etc. The robot controller  4  detects the position and posture of the robot  1  based on the output of the position detectors  18 . 
     Further, a position detector  22  is attached to the table drive motor  20 . The output of the position detector  22  is input to the robot controller  4 . The rotation angle of the table  6  can be detected by the output of the position detector  22  of the table drive motor  20 . The operation control unit  43  controls the table drive motor  20  so that the table  6  has a rotation angle set in the operation program  41 . The rotation angle of the table drive motor  20  is controlled so that the printed board can be disposed at a desired position. Further, the robot  1  changes its position and posture based on the operation program  41 , and thereby the flux can be ejected to a desired part of the printed board, the desired part of the printed board can be preheated, and the solder can be supplied to the desired part of the printed board. 
       FIG. 15  is a perspective view of the robot apparatus of the present embodiment for explaining the first process of soldering performed by the robot apparatus. The table  6  according to the present embodiment is divided into two areas. The table  6  includes a first area in which the opening  6   a  is formed and a second area in which the opening  6   b  is formed. In the example shown in  FIG. 15 , the first area in which the opening  6   a  is formed is disposed on the front side, and the second area in which the opening  6   b  is formed is disposed on the rear side. In the present embodiment, a soldering operation is performed for each area. 
     In the present embodiment, the printed board is transferred to and from the area disposed on the front side. First, a plurality of printed boards  34   a  are arranged in the opening  6   a . Electronic components  36  that are not secured are disposed on each printed board  34   a . Also in the present embodiment, the pallets  33 , on which a plurality of printed boards  34   a  are placed, are conveyed. The pallets  33  can be conveyed by a robot for conveying pallets. Alternatively, an operator may arrange the pallets  33  in the opening  6   a  of the table  6 . Subsequently, the robot controller  4  rotates the table  6  as indicated by arrow  93 . 
       FIG. 16  is a perspective view of the robot apparatus for explaining the second process of soldering. The table  6  is rotated and thereby transfers the printed board  34   a  disposed in the opening  6   a  of the first area to the rear side. 
       FIG. 17  is an enlarged perspective view of the placement member and the robot for explaining the third process of soldering. A flux application control for applying flux to the printed board  34   a  placed in the first area is performed. The robot controller  4  causes the robot  1  to change its position and posture so as to couple the flux ejection tool  2  to the wrist  15  of the robot  1 . The position of the flux ejection tool  2  on the placement member  28  is predetermined. Thus, the robot  1  changes its position and posture based on the operation program  41  so as to couple the flux ejection tool  2 . 
       FIG. 18  is an enlarged perspective view of the robot apparatus for explaining the fourth process of soldering. The robot  1  changes its position and posture so as to arrange the flux ejection tool  2  below the printed board  34   a  to which the flux is applied. The table  6  is disposed so as to have a predetermined rotation angle. Thus, each printed board  34   a  is disposed at a predetermined position. The robot  1  changes its position and posture based on the operation program  41  and thereby the nozzle  56  of the flux ejection tool  2  is arranged so as to face a desired portion of the printed board  34   a.    
     The robot controller  4  causes the valve of the nozzle  56  to be opened so as to eject flux therethrough. Further, the flux is applied to a portion to be soldered of each printed board  34   a . In this way, the robot controller  4  causes the flux to be applied to a portion to be soldered. It should be noted that, in the flux application control, a plurality of flux ejecting operations may be performed in one printed board  34   a  while the position of the flux ejection tool  2  is changed. 
       FIG. 19  is a perspective view of the robot apparatus for explaining the fifth process of soldering. While the robot  1  applies the flux to the printed board  34   a  disposed in the first area of the table  6 , printed boards  34   b , which are new workpieces, are arranged in the opening  6   b  in the second area. The printed boards  34   b  of the present embodiment are placed on the pallet  33  and conveyed. 
     After a control for applying flux to all the printed boards  34   a  disposed in the first area is completed, the robot controller  4  causes the table  6  to rotate as indicated by arrow  94 . The robot controller  4  causes the printed boards  34   a  disposed in the first area to move to the front side. The new printed boards  34   b  disposed in the second area move to the rear side. 
       FIG. 20  is an enlarged perspective view of the robot apparatus for explaining the sixth process of soldering. The robot controller  4  controls the robot so that the operation tool connected to the wrist  15  is changed from the flux ejection tool  2  to the support tool  3 . The robot  1  places the flux ejection tool  2  at a predetermined position of the placement member. The robot  1  couples the wrist  15  to the support tool  3 . The position of the support tool  3  in the placement member  28  is predetermined. Thus, the robot  1  changes its position and posture based on the operation program  41  so as to be coupled to the support tool  3 . 
       FIG. 21  is an enlarged perspective view of the solder pot and the robot for explaining the seventh process of soldering. The robot  1  changes its position and posture and thereby couples the base member  61  of the support tool  3  to the bottom surface of the solder pot V. The robot  1  supports the solder pot  7  via the support tool  3 . The position of the solder pot  7  on the placement member  28  is predetermined. Thus, the robot  1  changes its position and posture based on the operation program  41  and thereby supports the solder pot  7  with the support tool  3 . 
       FIG. 22  is an enlarged perspective view of the robot apparatus for explaining the eighth process of soldering. The robot controller  4  performs a preheating control for heating the printed board  34   a  by heat released from the solder pot  7 . The robot controller  4  controls the robot  1  so that the solder pot  7  is moved closer to a portion to be soldered of each printed board  34   a . The table  6  is disposed so as to have a predetermined rotation angle. Thus, each printed board  34   a  is disposed at a predetermined position. The robot  1  changes its posture based on the operation program  41  so as to move the solder pot  7  to a predetermined position with respect to the printed board  34   a . The solder pot  7  is spaced from the printed board  34   a  by a predetermined distance. In the present embodiment, the area surrounded by the wall part  72   a  of the solder pot  7  is disposed directly below a portion to be soldered. 
     In the solder pot  7  of the present embodiment, an opening is formed between the wall part  72   a  and the nozzle  31   a  (see  FIG. 10 ). Molten solder is stored within the solder pot  7 . The temperature of the solder is, for example, 200° C. or more and 300° C. or less. High-temperature air rises from the area surrounded by the wall part  72   a , as indicated by arrow  95 . The printed board  34   a  can be heated by the high-temperature air which is brought into contact with the back surface of the printed board  34   a . For example, the printed board  34   a  can be preheated by disposing the solder pot  7  near the printed board  34   a  in a predetermined time length. 
     Thus, the area surrounded by the wall part  72   a  is disposed below a portion to be soldered, and thus the portion to be soldered can be locally heated. When a plurality of portions are soldered in one printed board, the robot controller  4  may perform the preheating control for the plurality of portions. Further, the robot controller  4  performs the preheating control for all the printed boards  34   a  disposed in the first area. 
     In the preheating control of the present embodiment, a preheating operation before the solder is applied can be performed by using heat released from the solder pot  7 . Thus, it is not necessary to provide a device for heating a portion to be soldered, and the robot apparatus can be reduced in size. 
       FIG. 23  is an enlarged perspective view of the robot apparatus for explaining the ninth process of soldering. After the preheating of a printed board  34   a  is completed, the robot controller  4  performs a supply control for moving the nozzle  31   a  closer to the printed board  34   a  so as to supply solder to a portion to be soldered. Based on the operation program  41 , the robot controller  4  causes the robot  1  to change its position and posture and thereby causes the opening at the tip of the nozzle  31   a  to face the portion to be soldered. The nozzle  31   a  is arranged so as to be away from the printed board  34   a  by a predetermined distance. In the present embodiment, the solder pot  7  is disposed at a position closer to the printed board  34   a  than the position in the preheating control. 
     Subsequently, the motor  73  of the solder pot  7  is driven and thereby the solder flows out from the tip of the nozzle  31   a . The solder flowed out from the tip of the nozzle  31   a  comes into contact with the printed board  34   a , and thus the solder can be applied to the printed board  34   a . The electronic components  36  are secured to the printed board  34   a  and connected to an electric circuit of the printed board. 
     The robot controller  4  performs a supply control for supplying solder to all the printed boards  34   a  disposed in the first area. Further, when a plurality of portions in one printed board are soldered, the solder may be supplied to a plurality of portions in one printed board. 
     After the supply of the solder is completed, the robot controller  4  controls the robot  1  so that the solder pot  7  is disposed at a predetermined position in the placement member  28 . A notch  28   b  is formed in the placement member  28 . The robot controller  4  can control the robot  1  so that the tool-side plate  53  is disposed inside the notch  28   b.    
     Subsequently, the robot apparatus  5  starts a soldering operation for the printed boards  34   b  arranged in the second area on the rear side (see  FIG. 20 ). A flux application control for applying flux to the printed boards  34   b  arranged in the opening  6   b  is performed. While the robot apparatus  5  applies the flux to the printed boards  34   b  arranged in the opening  6   b  in the second area, the printed boards  34   a  arranged in the opening  6   a  in the first area are discharged. The printed boards  34   a  can be discharged by a robot for discharging the printed boards  34   a . Alternatively, the operator may discharge the printed boards  34   a . Further, new printed boards  34   a  can be disposed in the opening  6   a.    
     In the robot apparatus  5  of the present embodiment, while flux is applied to the printed boards in the area on the rear side, the printed boards arranged in the area on the front side are discharged. Further, new printed boards can be arranged in the area on the front side. Thus, the table  6  has a plurality of areas in which workpieces are arranged. The robot controller  4  continuously performs a flux application control, a preheating control, and a supply control for the areas one by one. By performing these controls, while the flux is applied to the printed boards arranged in one area, the printed boards that have been soldered can be discharged or new printed boards can be introduced. As a result, the soldering operation time can be shortened. 
     It should be noted that the table of the present embodiment is divided into two areas, but is not limited to this configuration. The table may be divided into three or more areas. Even in this case, the flux application control, the preheating control, and the supply control can be continuously performed for each area. 
     In the robot apparatus  5  in the present embodiment, one robot apparatus can continuously perform operations, i.e., from a flux applying operation to a solder supplying operation. A conveying device, such as a conveyor for conveying printed boards between a flux applying device, a preheating device, and a solder supplying device, is not necessary. In the robot apparatus  5  of the present embodiment, the robot  1  applies flux by using an operation tool. Further, the robot moves the solder pot  7  so as to preheat the printed boards  34   a  and  34   b  and supply solder to the printed boards. The robot apparatus  5  for soldering of the present embodiment is small and can automatically perform soldering. 
     Furthermore, the robot apparatus  5  according to the present embodiment can automatically replace the nozzle  31   a  of the solder pot  7  with another nozzle. Referring to  FIG. 5 , a plurality of types of nozzles  31   b ,  31   c  and  31   d  are placed on the placement member  28  of the present embodiment. The robot apparatus  5  of the present embodiment can replace the nozzle  31   a  disposed in the solder pot  7  with any of the nozzles  31   b ,  31   c  and  31   d.    
       FIG. 24  is an enlarged perspective view of the support tool and the solder pot for explaining the first process of nozzle replacement of the present embodiment. The robot controller  4  causes the wrist  15  of the robot  1  to be coupled to the support tool  3 . The robot controller  4  causes the robot  1  to change its position and posture and thereby causes the chuck part  62  of the support tool  3  to be disposed so as to face the turning member  74  of the solder pot  7 . 
       FIG. 25  is an enlarged perspective view of the support tool and the solder pot for explaining the second process of replacing the nozzle of the solder pot. The robot controller  4  controls the robot  1  and the support tool  3  so that the claws  64  grasp the tip of the turning member  74  of the solder pot  7 . The robot controller  4  causes the chuck part  62  to move downward as indicated by arrow  96  after the claws  64  grasp the tip of the turning member  74 . As indicated by arrow  99 , the turning member  74  rotates about the axis as a rotation center supported by the support member  75 . 
       FIG. 26  is an enlarged perspective view of the support tool and the solder pot for explaining the third process of replacing the nozzle of the solder pot. As the turning member  74  is turned, the turning member  74  moves away from the engagement part  35  of the nozzle  31   a . In this way, the securing of the nozzle  31   a  is released. 
       FIG. 27  is an enlarged perspective view of the support tool and the solder pot for explaining the fourth process of replacing the nozzle of the solder pot. After the turning member  74  is separated from the engagement part  35  of the nozzle  31   a , the chuck part  62  releases the turning member  74 . 
       FIG. 28  is an enlarged perspective view of the support tool and the solder pot for explaining the fifth process of replacing the nozzle of the solder pot. Subsequently, the robot controller  4  controls the robot  1  and the chuck part  62  so that the claws  64  of the chuck part  62  grasp the engagement part  35  of the nozzle  31   a . Further, after the chuck part  62  grasps the engagement part  35 , the robot controller  4  causes the robot  1  to change its position and posture so as to pull out the nozzle  31   a  from the container  71  of the solder pot  7 . 
     The robot controller  4  performs a control in which the nozzle  31   a  reciprocates in a predetermined direction immediately after the nozzle  31   a  is removed from the solder pot  7 . In the present embodiment, the robot  1  stops when the nozzle  31   a  is slightly away from the solder pot  7 . Subsequently, the robot  1  performs a control in which the nozzle  31   a  reciprocates in the vertical direction as indicated by arrow  100 . By performing this control, the molten solder that adheres to the nozzle  31   a  can be dropped. The dropped solder returns to the inside of the container  71  through the space within the wall part  72   a.    
     Alternatively, the robot  1  may reciprocate the nozzle  31   a  in the horizontal direction. Furthermore, the robot  1  may move the nozzle  31   a  in the horizontal direction and may cause the nozzle  31   a  to collide with the inner surface of the wall part  72   a . These controls also cause the molten solder that adheres to the nozzle  31   a  to be dropped. Thus, the solder that adheres to the nozzle  31   a  can be returned to the inside of the container  71 . 
     Subsequently, the robot controller  4  causes the robot  1  to change its position and posture and thereby causes the removed nozzle  31   a  to be placed at a predetermined position of the placement member  28 . After the robot  1  changes its position and posture, the chuck part  62  of the support tool  3  releases the nozzle  31   a , and thus the nozzle  31   a  can be placed on the placement member  28 . 
     Subsequently, the robot controller  4  performs a control for arranging a nozzle different from the nozzle  31   a  in the solder pot  7 . The robot controller  4  can perform controls in reverse procedure to the control for removing the nozzle  31   a  from the solder pot  7 , and thus a new nozzle is attached to the solder pot  7 . In other words, the chuck part  62  of the support tool  3  grasps the engagement part  35  of one of the nozzles  31   b ,  31   c  and  31   d . Further, the robot  1  changes its position and posture and thereby inserts the nozzle into the space surrounded by the wall part  72   a  of the solder pot  7 . The nozzle fits into the fitting member  76  of the solder pot (see  FIG. 12 ). Thereafter, the chuck part  62  releases the nozzle. 
     Subsequently, the robot  1  changes its position and posture and thereby causes the chuck part  62  of the support tool  3  to grasp the tip of the turning member  74  of the solder pot  7 . Further, the robot  1  changes its position and posture so as to turn the turning member  74 . The turning member  74  is turned and thereby the tip of the turning member  74  is engaged with the engagement part  35  of the nozzle. The nozzle is secured to the solder pot  7 . 
     In this way, the chuck part  62  of the support tool  3  of the present embodiment can operate the securing mechanism  80  of the nozzles  31   a ,  31   b ,  31   c  and  31   d . The solder pot  7  is formed so that a plurality of types of nozzles  31   a ,  31   b ,  31   c  and  31   d  can be attached thereto. The robot controller  4  performs a control for operating the securing mechanism  80  by the chuck part  62 . The robot controller  4  performs a control for grasping the nozzle by the chuck part  62 . The robot controller  4  performs a replacement control for replacing the nozzle disposed in the solder pot  7  with a nozzle placed on the placement member  28 . The replacement control for nozzles can be performed based on the operation program  41 . 
     It is preferable that the shape of the tip of the nozzle of the solder pot and the size of the opening at the tip correspond to the shape and size of a portion to be soldered. For example, when the portion to be soldered is small, it is preferable that the opening at the tip of the nozzle is small. Alternatively, not only components may be disposed on the upper side of the printed board, but also components may be disposed on the back side of the printed board. When the diameter of the tip of the nozzle is large, the nozzle may interfere with the components disposed on the back side of the printed board. In such a case, it is preferable to use a nozzle having a small tip diameter. Further, when a plurality of types of printed boards are soldered, it is preferable to replace the nozzle depending on the type of each printed board. 
     In the robot apparatus of the present embodiment, the nozzle of the solder pot can be automatically replaced depending on the size and shape of a portion to be soldered. Alternatively, when a plurality of portions in one type of printed board are soldered, the nozzle may be replaced with another nozzle during the period of soldering the one type of printed board in order to solder the plurality of portions. 
     Subsequently, the robot apparatus of the present embodiment can automatically perform a control for replenishing solder when the amount of solder stored in the solder pot decreases. The control for replenishing solder can be performed based on the operation program  41 . Referring to  FIG. 5 , auxiliary solder bars  32  are placed on the placement member  28 . The robot controller  4  performs a control for inserting the solder bar  32  into the solder pot  7  based on the operation program  41 . 
     In the solder pot  7  of the present embodiment, a sensor for detecting the amount of solder stored in the solder pot is disposed. Any sensor that can detect the amount of solder, such as a water level sensor, can be used as the sensor. The robot controller  4  detects the amount of solder inside the solder pot  7 . The robot controller  4  detects that the amount of solder is small. For example, the robot controller  4  detects the amount of solder that is less than a predetermined determination value. 
       FIG. 29  is an enlarged perspective view of the robot apparatus for explaining the first process of a control for replenishing the solder pot with solder. The robot controller  4  controls the robot  1  and the chuck part  62  so that a solder bar  32  is grasped by the chuck part  62  of the support tool  3 . The chuck part  62  grasps one of the solder bars  32  placed on the placement member  28 . 
       FIG. 30  is an enlarged perspective view of the robot apparatus for explaining the second process of the control for replenishing the solder pot with solder. The robot controller  4  causes the robot  1  to change its position and posture and thereby causes the solder bar  32  to be inserted into a hole  72   b  as an insertion port formed in the lid member  72  of the solder pot  7  as indicated by arrow  97 . The solder bar  32  is inserted into the solder pot  7  and then melted. 
     In this way, the robot  1  and the chuck part  62  of the support tool  3  are controlled so as to replenish the solder bar  32 . In the robot apparatus  5  of the present embodiment, it is not necessary to arrange a device for supplying solder, and the configuration of the device for soldering can be simplified. It is also conceivable to arrange a device for supplying solder formed in a linear shape to the solder pot. However, when the solder formed in a linear shape is supplied, there is the problem that it takes a long time to supply the solder. By supplying the solder bar as in the present embodiment, the time required for supplying the solder can be shortened. 
     The support tool for supporting the solder pot in the present embodiment has a chuck part that can grasp a workpiece, but is not limited to this configuration. Apart from the support tool, an operation tool such as a hand tool for grasping the workpiece can be disposed. This operation tool can also be placed on the placement member. However, as in the present embodiment, the chuck part is disposed on the support tool, and thus the number of operation tools can be reduced, and the size of the robot apparatus can be reduced. 
       FIG. 31  shows another flux ejection tool according to the present embodiment. Another flux ejection tool  8  of the present embodiment has a surrounding member  59  disposed around the nozzle  56 . The surrounding member  59  is formed so as to surround the nozzle  56 . Further, the surrounding member  59  in the present embodiment is formed into a conical shape. The surrounding member  59  is formed so that the inner diameter increases toward the tip of the nozzle  56 . 
     When the flux is ejected from the tip of the nozzle  56 , the flux may scatter and may contaminate members inside the robot apparatus  5 . The surrounding member  59  is disposed in the flux ejection tool  8 , and thus the flux can be suppressed from being scattered around. For example, it is possible to suppress the flux from adhering to the surface of the device disposed inside the frame body  26 . 
     In the above embodiments, the workpiece is preheated with high-temperature air generated in the solder pot, but the embodiment is not limited to this. An operation tool for preheating the workpiece may be disposed separately from the solder pot. 
       FIG. 32  is a perspective view of a preheating tool of the present embodiment. The preheating tool  9  is an operation tool coupled to the wrist  15  of the robot  1 . The preheating tool  9  includes a base member  66  and an electric heater  67  serving as a heater disposed on the surface of the base member  66 . The temperature of the electric heater  67  increases when the electricity is supplied via a cable  68 . The preheating tool  9  is coupled to the robot-side plate  51 , which is secured to the wrist  15  of the robot  1 , via the tool-side plate  54 . 
     The preheating tool  9  can be placed on the placing member when not in use. For example, a notch corresponding to the electric heater  67  can be formed in the placement member. The preheating tool  9  can be placed on the placement member so that the electric heater  67  is disposed inside the notch. 
     When the robot apparatus includes the preheating tool  9 , the flux application control can be performed in the same manner as the above-described control. In a preheating control, the robot controller  4  changes the operation tool coupled to the robot  1  from the flux ejection tool  2  to the preheating tool  9 . The robot controller  4  causes the robot  1  to change its position and posture so as to move the preheating tool  9  closer to one printed board  34   a ,  34   b . The robot  1  arranges the electric heater  67  so that the electric heater faces the printed board  34   a ,  34   b . This control enables the printed board  34   a ,  34   b  to be heated. Thereafter, the robot controller  4  changes the operation tool coupled to the robot  1  to the support tool  3 . The robot controller  4  can perform a supply control for supporting the solder pot  7  by the robot  1  and supplying solder to a portion to be soldered. 
     Even in the robot apparatus provided with the preheating tool of the present embodiment, it is not necessary to convey the printed board among a flux applying device, a substrate preheating device, and a solder supplying device. Thus, the size of the apparatus for soldering can be reduced. 
     In the present embodiment, the position and posture of the robot are controlled so as to be the position and posture which are predetermined in the operation program, but are not limited to this configuration. For example, a camera may be disposed on a wrist or a chuck part of the robot. The robot controller may detect a position of an object to be operated based on the image captured by the camera. For example, the robot controller may detect, for example, the position of the operation tool placed on the placement member, the position of the printed board, and the position of the turning member of the solder pot, based on the image captured by the camera. 
     The workpiece of the present embodiment is a printed board, but is not limited to this configuration. Any workpiece can be adopted as a workpiece to be soldered. 
     In the present embodiment, all operation tools and members necessary for soldering are arranged on the surface of one placement member, but are not limited to this configuration. The robot apparatus may include a plurality of placement members. For example, operation tools and members necessary for soldering may be separately placed on a plurality of placement members. 
     According to an aspect of this disclosure, it is possible to provide a small robot apparatus that can perform soldering. 
     In each of the above-described controls, the order of the steps can be appropriately changed within a range where the function and the action are not changed. 
     The above embodiments can be combined as appropriate. In the respective drawings described above, the same or equivalent parts are denoted by the same reference numerals. It should be noted that the above embodiments are for purposes of illustration and do not limit the invention. Further, in the embodiments, modifications of the embodiments shown in the claims are included.