JP2016049556A - Welding system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem with a robot system constituted for switching connection of one welder and any of a plurality of welding wire feeders, which has the function of detecting abnormal connection of the welder and the corresponding welding wire feeder, in which abnormal connection is erroneously detected when switching connection of the welder and any of the welding wire feeders.SOLUTION: A welding system comprises one welder and a plurality of welding wire feeders, and when a robot control device switches from a state of connecting the welder and a first feeder via the switching device to a state of connecting the welder and a second feeder by controlling a switching device in a state of being capable of controlling a robot, the robot control device does not detect abnormal connection for a predetermined period up to after switching connection from before switching connection. Thus, detection of abnormal connection can be prevented when switching connection, and an abnormal connection detection function can be compatible with a connection switching function.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a welding system that includes a welding machine, a welding torch, and a welding wire feeding device and performs welding using a desired welding wire among a plurality of welding wires.

  In recent years, there is an increasing need for a robot system that can perform welding by selecting a required welding wire from a plurality of welding wires in order to increase the operating rate of automatic welding equipment. Moreover, in order to improve the feedability of the welding wire, the number of welding torches integrated with the welding wire feeding device is increasing. Therefore, there is a need for a welding wire feeder that is small in size and can be attached to a welding torch.

  As a conventional robot system that performs welding by selecting a required welding wire from a plurality of welding wires, one shown in FIG. 3 is known (for example, see Patent Document 1). This robot system includes a plurality of wire units 101 and 102 each containing a welding wire, a branch guide 103, a welding torch 104, welding wire feeding devices 105 and 106, and a cutting device 107 as main components.

  This robot system performs welding by selecting either the welding wire 109 or the welding wire 111 from the welding wires 109 and 111 accommodated in the wire units 101 and 102 according to the workpiece and the welding location.

  Here, first, welding is performed using the welding wire 109 accommodated in the wire unit 101, and then welding is performed using the welding wire 111 accommodated in the wire unit 102. The operation of the system will be described.

  First, the welding wire 109 wound around the wire unit 101 located on the left side in FIG. 3 is supplied to the welding torch 104 via the branch guide 103 by the normal rotation of the welding wire feeder 106. At this time, the robot body 108 positions the distal end portion of the welding wire 109 at a cutting position where the cutting device 107 can cut the distal end of the welding wire 109. The cutting device 107 cuts the tip of the welding wire 109 and aligns the protruding length of the welding wire 109 to a predetermined length. The normal rotation is a rotation direction of a motor constituting the welding wire feeding device 106 for feeding the welding wire 109 to the welding torch 104 side.

  Next, the robot body 108 positions the tip end portion of the welding wire 109 at the welding position of the workpiece, and performs predetermined welding using the welding torch 104 in this state.

  Next, the robot body 108 positions the tip portion of the welding wire 109 at a position where the cutting device 107 can cut the tip of the welding wire 109. The cutting device 107 has a welding ball formed at the tip of the welding wire 109. Cut off. Thereafter, the welding wire 109 is pulled back from the welding torch 104 to the wire receiving port 110 of the branch guide 103 by the reverse rotation of the welding wire feeding device 106.

  Next, the welding wire 111 wound around the wire unit 102 located on the right side in FIG. 3 is supplied to the welding torch 104 via the branch guide 103 by the normal rotation of the welding wire feeder 105. At this time, the robot body 108 positions the tip portion of the welding wire 111 at a cutting position where the cutting device 107 can cut the tip of the welding wire 111. The cutting device 107 cuts the tip of the welding wire 111 and aligns the protruding length of the welding wire 111 to a predetermined length.

  Next, the robot body 108 positions the distal end portion of the welding wire 111 at the welding position of the workpiece, and performs predetermined welding using the welding torch 104 in this state.

JP-A-62-124078

  In the welding torch in which the welding wire feeding device is integrated, the wire feeding device is attached to the welding torch. Therefore, the welding wire cannot be pulled back to the wire receiving port 110 attached to the upper part of the robot main body 108 of the conventional robot system. For this reason, a welding torch in which a welding wire feeder is integrated cannot be applied to a conventional robot system.

  Further, in the conventional robot system, when switching the welding wire, the welding wire that has been used has to be pulled back to the wire receiving port 110, and the welding wire to be used next must be fed again. Therefore, it is necessary to independently control feeding and pulling back of each welding wire. Therefore, when increasing the number of welding wires that can be fed, wire feeding devices are required as many as the number of welding wires, and the same number of welding machines are required to control the feeding devices. Was.

  Further, the conventional robot system has a structure in which the welding wire feeding device is arranged on the upper portion of the robot body 108. Therefore, the plurality of welding wire feeding devices and the fixtures for fixing them operate together with the arm constituting the robot main body 108, and they interfere with the workpiece, the jig for fixing the workpiece, etc. There was a problem that the work range of the above was limited.

  Further, even when the welding wire feeding device is not arranged on the upper part of the robot body 108, a space for installing the welding wire feeding device that must be increased is increased. Furthermore, a space for arranging a control device for a plurality of welding wire feeding devices, a control line connecting the welding wire feeding devices and the control device, and the like is required regardless of the location of the welding wire feeding device. For these reasons, there is a problem that the working range of the robot is limited by the increased space.

  In addition, if the number of welding wire feeding devices or welding machines that control the welding wire feeding device is increased in order to increase the number of wires that can be fed, there is a problem that the cost of the robot system increases accordingly. Not too long.

  In order to suppress an increase in the cost of the robot system, it is also conceivable to use one welding machine and switch the connection between the welding machine and the welding wire feeder. However, when the robot system has a function of detecting a connection abnormality between the welding machine and the welding wire feeding device, the connection abnormality is erroneously detected when switching the connection between the welding machine and the welding wire feeding device. The problem that it ends up occurs.

  Further, in the robot system shown in FIG. 3, when the welding wire to be used is changed, it is necessary to repeatedly pull back and feed the welding wire, and further, since the branch guide 103 is used, the welding wire feeding is performed. The route is complicated, and there is a problem that a trouble such as the welding wire buckling occurs in the welding wire feeding route.

  In order to solve the above-described problems, a welding system according to the present invention includes a first welding torch, a second welding torch, and a first feeding for feeding a first welding wire to the first welding torch. An apparatus, a second feeding device for feeding a second welding wire to the second welding torch, a welding machine for controlling the first feeding device and the second feeding device, A switching device for switching connection of the first feeding device and the second feeding device to the welding machine, a robot for holding and holding the first welding torch and the second welding torch, and the robot And a switching device and a robot control device for controlling the welding machine, the robot control device comprising: a connection abnormality between the welding machine and the first feeding device; the welding machine; The robot control device has a function of detecting a connection abnormality with a feeding device of the robot In a state where the robot can be controlled, the welding device and the second feeding device are controlled by controlling the switching device from a state where the welding machine and the first feeding device are connected via the switching device. When switching to a state in which the feeding device is connected, the robot control device does not detect the connection abnormality for a predetermined period from before switching the connection to after switching.

  In addition to the above, the welding system of the present invention switches from a state where the welding machine and the first feeding device are connected to a state where the welding machine and the second feeding device are connected. Before, the welding machine decreases the command current supplied to the first feeding device.

  In the welding system of the present invention, in addition to the above, the welding machine sets the command current to zero.

  In addition to the above, the welding system of the present invention has the first welding torch and the first feeding device as an integrated configuration, and the second welding torch and the second feeding device as an integrated configuration. .

  In addition to the above, the welding system of the present invention switches from a state in which the welding machine and the first feeding device are connected to a state in which the welding machine and the second feeding device are connected. Then, based on a command from the robot control device, the welding machine acquires information on the electrical angle of the motor used in the second feeding device.

  Moreover, in addition to the above, the welding control system of the present invention includes a first welding condition that is a welding condition for welding performed in a state in which the robot controller is connected to the welding machine and the first feeding device. A storage unit configured to store a second welding condition that is a welding condition of welding performed in a state where the welding machine and the second feeding device are connected, and the robot control device includes: When the first feeding device is connected, the welding machine is controlled based on the first welding condition.

  In addition to the above, the welding system of the present invention is provided with a welding machine in the robot controller.

  As described above, according to the present invention, by using a single welding machine and a switching device, a plurality of welding torches and welding wire feeding devices to be used can be switched from a plurality of welding torches and welding wire feeding devices. The necessary welding wire can be fed. And the welding system of this invention has the function to detect the connection abnormality of the wiring between a welding wire feeder and a welding machine, and before switching the connection of a welding machine and a welding wire feeder. Connection abnormality is not detected for a predetermined period until switching. Therefore, it is possible to prevent a connection abnormality from being detected during connection switching, and to achieve both a connection detection function and a connection switching function.

The figure which shows schematic structure of the welding system in Embodiment 1 of this invention. The flowchart which shows the switching procedure of the welding wire in Embodiment 1 of this invention. The figure which shows schematic structure of the conventional welding system

(Embodiment 1)
FIG. 1 is a diagram showing a schematic configuration of a welding system in the present embodiment. In the present embodiment, a case where the welding torch and the welding wire feeding device are integrated will be described as an example.

  With reference to FIG. 1, a welding system according to the present embodiment will be described. In FIG. 1, the welding wire units 1a and 1b accommodate reels wound with different types of welding wires 2a and 2b. The welding wires 2a and 2b accommodated in the welding wire units 1a and 1b pass through the torch cables 3a and 3b, reach the welding torches 4a and 4b, and are fed by the welding wire feeding devices 5a and 5b.

  The welding torches 4a and 4b are integrated with the welding wire feeders 5a and 5b, and are attached to the robot 17c by a method described later. The welding wire feeding devices 5a and 5b have feeding motors 6a and 6b, and feed the welding wires 2a and 2b by driving them. Signals and electric power for driving the feeding motors 6a and 6b and electric power necessary for welding are sent from the welding machine 12c via the wire feeder cables 7a and 7b. The wire feeder cables 7a and 7b are connected to the switching device 10c.

  The switching device 10c is connected to the welding machine 12c by the first cable 11c. The switching device 10c has a function of connecting one of the wire feeder cables 7a and 7b to the first cable 11c.

  The robot control device 14c is connected to the welding machine 12c by the second cable 13c. The robot control device 14c is connected to the switching device 10c by a third cable 15c. The robot control device 14c is connected to the robot 17c by a fourth cable 16c. Thereby, the robot control apparatus 14c can communicate with the switching apparatus 10c, the welding machine 12c, and the robot 17c, and can exchange required information.

  The robot control device 14c has a storage unit 19c. The robot controller 14c stores information on welding conditions suitable for welding using the welding wires 2a and 2b, welding operations using the welding torches 4a and 4b, and replacement operations of the welding torches 4a and 4b in the storage unit 19c. Is remembered. Based on the information stored in the storage unit 19c, the robot controller 14c sends commands to the switching device 10c, the welding machine 12c, and the robot 17c to control them.

  The welding torches 4a and 4b are supported by torch holders 8a and 8b. When welding is performed using the welding torch 4a, the welding torch 4a is attached to the robot 17c by a gripping device 18c provided on the robot 17c, and the welding torch 4b is held in a detachable state on the tool stand 9b. . On the other hand, when welding is performed using the welding torch 4b, the welding torch 4b is attached to the robot 17c by the gripping device 18c, and the welding torch 4a is held in a detachable state on the tool stand 9a.

  Next, referring to FIG. 1, a procedure for switching between the welding torch 4a and the welding torch 4b used by the robot 17c based on a control command from the robot controller 14c, that is, the welding wire 2a and the welding wire 2b to be used. The procedure for switching between will be described. When welding torch 4a is first attached to robot 17c, welding is performed using welding wire 2a, welding torch 4a is then removed, welding torch 4b is installed, and welding is performed using welding wire 2b. Will be described as an example. FIG. 2 is a flowchart summarizing a series of welding and switching operations.

  In addition, as a specific example when switching of a welding wire is required, it is a case where different workpieces are welded by one welding system, and welding is performed using a welding wire suitable for the workpiece. Examples include switching to a welding wire.

  First, the welding torch 4a is attached to the robot 17c, and welding is performed using the welding wire 2a. At this time, the first cable 11c and the wire feeder cable 7a are connected by the switching device 10c. Thereby, the robot controller 14c sends a command to the welding wire feeder 5a that feeds the welding wire 2a via the welding machine 12c, and controls the welding wire feeder 5a. All commands necessary for controlling the welding system are stored in the storage unit 19c of the robot control device 14c. The robot control device 14c has a function of detecting a connection abnormality for confirming whether or not it is connected to the welding wire feeding device 5a, and always confirms whether or not there is an abnormality. Here, the detection of the connection abnormality is performed in the communication process between the robot control device 14c and the welding wire feeding device 5a. The welding wire feeder 5a transmits dedicated communication data for determining a connection abnormality to the robot controller 14c at regular intervals. When the robot controller 14c receives a connection abnormality signal continuously for a certain number of times or more, it determines that the connection is abnormal and detects a connection abnormality.

  Subsequently, when the welding using the welding torch 4a is completed, the switching device 10c connects the welding machine 12c from the welding wire feeding device 5a to the welding wire feeding device 5b based on a command from the robot control device 14c. Change to

  Specifically, first, the command current sent to the welding wire feeder 5a by the wire feeder cable 7a is set to zero. By switching the command current to 0, the current flowing in each of the welding wire feeding device 5a and the welding wire feeding device 5b is switched in a state of 0, so that the current does not change suddenly at the time of connection switching, The electrical load applied to the switching device 10c can be reduced. Further, by setting the command current to 0, the device can be brought into a state equivalent to when the power is turned off. If the command current is 0, the device after switching will not operate unexpectedly after switching when the connection is switched.

  When the connection of the welding machine 12c is changed from the welding wire feeder 5a to the welding wire feeder 5b, the robot controller 14c sends the welding wire feeder connected by the wire feeder cable 7a and the first cable 11c. The function of detecting a connection abnormality between the feeding device 5a and the welding machine 12c is temporarily disabled.

  Next, the robot control device 14c instructs the switching device 10c to switch the wiring via the third cable 15c. The switching device 10c switches the connection of the first cable 11c from the wire feeding device cable 7a to the wire feeding device cable 7b based on an instruction from the robot control device 14c.

  After switching the connection, the robot control device 14c validates the connection abnormality detection function, and checks whether there is an abnormality in the connection between the robot control device 14c that has made the connection and the welding wire feeder 5b. In addition, since the side of the welding wire feeding device 5a before switching is in a state in which the connection is not established, a connection abnormality between the welding wire feeding device 5a and the welding machine 12c is not detected. Here, if there is an abnormality in the connection after switching, it is determined that the connection has not been made, and the robot control device 14c stops the operation.

  Thereafter, the welding machine 12c and the robot control device 14c send a command current to the welding wire feeding device 5b via the wire feeding device cable 7b to drive the electric motor of the feeding motor 6b that drives the welding wire feeding device 5b. Obtains information about the angle and initializes the angle sensor of the motor.

  Thus, in a certain period including a period during which the connection between the welding machine 12c and the welding wire feeding devices 5a and 5b is switched, an abnormal connection of wiring between the welding machine 12c and the welding wire feeding devices 5a and 5b is caused. Disable detection. By switching the connection during the period when connection abnormality is not detected, it is possible to prevent connection abnormality from being detected due to the unconnected state that occurs at the time of connection switching. Connection switching function and connection abnormality detection function And both.

  Furthermore, the robot control device 14c sends the welding conditions when using the welding wire 2b stored in the storage unit 19c to the welding machine 12c. The welding machine 12c that has received the welding condition changes the welding condition from the welding condition that it had so far to the welding condition received from the robot controller 14c. In addition, the robot control device 14c changes a command necessary for controlling the robot 17c to a command suitable for the welding torch 4b based on information stored in the storage unit 19c.

  Next, the welding torch 4a and the welding torch 4b are exchanged. Specifically, first, the welding torch 4a gripped by the gripping device 18c of the robot 17c is positioned at a predetermined position on the tool stand 9a, and the gripping of the torch holder 8a by the gripping device 18c is released. Thereby, the welding torch 4a and the torch holder 8a are held by the tool stand 9a in a detachable state. Thereafter, the gripping device 18c of the robot 17c is positioned at a predetermined position of the tool stand 9b, and the welding torch 4b is gripped by the robot 17c via the torch holder 8b by the gripping device 18c.

  Next, the robot 17c positions the welding torch 4b at a predetermined position based on a command from the robot controller 14c, and performs welding at a predetermined position of the workpiece. At this time, the first cable 11c and the wire feeder cable 7b are connected by the switching device 10c. Thereby, the robot control apparatus 14c can control the welding wire feeding apparatus 5b which is feeding the welding wire 2b via the welding machine 12c, and can supply electric power required for welding with respect to the welding torch 4b. it can.

  As described above, according to the welding system of the present embodiment, the welding torches 4a and 4b held by the robot 17c are changed. Moreover, the connection between the welding machine 12c and the welding wire feeding device 5a and the connection between the welding machine 12c and the welding wire feeding device 5b are changed by the switching device 10c. Thereby, the welding wires 2a and 2b to be used can be changed.

  Therefore, unlike the conventional system, there is no need to repeatedly pull back and feed the welding wire, and the branch guide 103 is not used, so that the welding wire feeding path is not complicated and the welding wire feeding is not performed. Troubles such as the buckling of the welding wire in the feed path can be prevented, and a highly reliable welding system can be realized.

  Further, the welding system of the present embodiment uses one welding torch and one welding wire feeder for one type of welding wire. When switching the welding wire, the welding torch and the welding wire feeding device in which the welding wire can be fed are handled as one set of devices, and these devices are replaced. And a welding wire is switched by switching the connection of a welding wire feeder and a welding machine.

  As shown in FIG. 1, when the wire feeding device is integrated with the welding torch, the wire feeding device can be exchanged together by replacing the welding torch attached to the robot 17c. Further, even when the wire feeding device is not integrated with the welding torch, the wire feeding device does not need to be attached to the robot 17c and can be easily installed. In addition, since the wire feeding apparatus should just be connected with the switching apparatus 10c, what is necessary is just to install side by side with the switching apparatus 10c, for example.

  Further, the welding torch and the wire feeding device attached to the robot 17c are only one set in which a welding wire to be welded is set. What is necessary is just to hold | maintain the welding torch and the wire feeding apparatus in which the welding wire which is not used is set to the tool stand as shown in FIG. Thus, since it is not necessary to attach the apparatus which is not used to the robot 17c, the apparatus attached to the robot 17c does not enlarge. Therefore, space saving can be realized and the weight of the device attached to the robot 17c can be light.

  In the present embodiment, the case where two types of welding wires are used has been described as an example. However, three or more types of welding wires may be used. In this case, the configuration of the switching device 10c can be switched as many as the number of welding wires to be switched. As many welding torches and wire feeders as the number of welding wires to be switched are prepared, and the wire feeder and the switching device are connected. Since the welding machine can be connected to the wire feeding device of the welding torch on which the welding wire to be welded is set by the switching device, only one welding machine is required. Since the switching device 10c need only have a simple function of changing the connection in response to a command from the robot control device 14c, it does not cost much. And since it is not necessary to increase the welding machine which has a complicated function, it can respond at low cost.

  Further, the welding operation and the welding torch replacement operation are realized by the robot control device 14c sequentially sending commands to the switching device 10c, the welding machine 12c, and the robot 17c. A program for performing a welding operation or a welding torch replacement operation is stored in advance in the storage unit 19c of the robot control device 14c, and a series of operations can be automatically performed by operating the robot system according to the program. Furthermore, the welding system of the present embodiment never has to turn off the power when switching the connection between the welding machine and the wire feeding device. When switching the welding wire, it is only necessary to replace the welding torch held by the robot 17c, and there is no need to replace the welding wire set on the welding torch. Therefore, a series of operations can be performed continuously and efficiently.

  As described above, in the welding system of the present embodiment, the connection between the welding machine 12c and the welding wire feeding devices 5a and 5b is switched by the switching device 10c, and the two welding wire feeding devices 5a are switched by one welding machine 12c. , 5b can be driven to select and feed two types of welding wires 2a, 2b. Thereby, the number of welding machines can be reduced. The specific effect is that when two types of welding wires are fed, one welding machine can be reduced, and when three types of wires are fed, two welding machines are reduced. Can do.

  In the present embodiment, the case where the welding torches 4a and 4b and the welding wire feeding devices 5a and 5b are integrated with each other has been described. However, it does not have to be integrated.

  Moreover, in this Embodiment, the case where two types of welding wires 2a and 2b were switched was shown. However, the present invention is not limited to this, and three or more types of welding wires may be switched.

  Further, the switching device 10c only has to switch the connection between the welding machine and the welding wire feeding device based on the control signal input from the robot control device 14c, and the configuration of the switching device 10c is not limited.

  Further, in the present embodiment, a case has been described in which the switching device 10c, the welding machine 12c, and the robot control device 14c are independent devices. However, these devices may be combined into one function as a single device. In that case, the wiring which connects each apparatus becomes unnecessary.

  According to the present invention, the welding wire to be used is changed by exchanging the welding torch and the welding wire feeding device to be gripped by the robot and switching the connection between the welding machine and the welding wire feeding device to be used. Therefore, the present invention is industrially useful as a welding system that performs welding by selecting a desired welding wire from among a plurality of welding wires.

1a, 1b Welding wire unit 2a, 2b, 109, 111 Welding wire 3a, 3b Torch cable 4a, 4b, 104 Welding torch 5a, 5b, 105, 106 Welding wire feeding device 6a, 6b Feeding motor 7a, 7b Wire feeding Feeder cable 8a, 8b Torch holder 9a, 9b Tool stand 10c Switching device 11c First cable 12c Welding machine 13c Second cable 14c Robot control device 15c Third cable 16c Fourth cable 17c Robot 18c Gripping device 19c Storage unit

Claims (7)

A first welding torch;
A second welding torch;
A first feeding device for feeding a first welding wire to the first welding torch;
A second feeding device for feeding a second welding wire to the second welding torch;
A welding machine for controlling the first feeding device and the second feeding device;
A switching device for switching connection of the first feeding device and the second feeding device to the welding machine;
A robot for holding and holding the first welding torch and the second welding torch;
A robot controller for controlling the robot, the switching device and the welding machine;
The robot control device has a function of detecting a connection abnormality between the welding machine and the first feeding device and a connection abnormality between the welding machine and the second feeding device,
In a state where the robot control device can control the robot, the welding device is controlled by controlling the switching device from a state where the welding machine and the first feeding device are connected via the switching device. When the robot controller switches to a state in which the second feeding device is connected, the robot control device does not detect the connection abnormality for a predetermined period from before switching to after switching. Before switching from a state in which the welding machine and the first feeding device are connected to a state in which the welding machine and the second feeding device are connected, the welding machine performs the first feeding. The welding system according to claim 1, wherein the command current supplied to the apparatus is reduced. The welding system according to claim 2, wherein the welding machine sets the command current to zero. The welding according to any one of claims 1 to 3, wherein the first welding torch and the first feeding device are integrally configured, and the second welding torch and the second feeding device are integrally configured. system. After switching from the state where the welding machine and the first feeding device are connected to the state where the welding machine and the second feeding device are connected, based on a command from the robot controller, The welding system according to any one of claims 1 to 4, wherein the welding machine acquires information related to an electrical angle of a motor used in the second feeding device. The robot control device includes a first welding condition, which is a welding condition of welding performed in a state where the welding machine and the first feeding device are connected, and the welding machine and the second feeding device are connected. A storage unit that stores a second welding condition that is a welding condition of welding performed in a state in which the robot controller is connected to the welding machine and the first feeding device The welding system according to claim 1, wherein the welding machine is controlled based on the first welding condition. The welding system according to any one of claims 1 to 6, wherein the welding machine is provided in the robot control device.

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