JP6205263B2 - Welding electrode management device - Google Patents

Description

  The present invention relates to a welding electrode management apparatus that outputs information related to replacement of non-consumable electrodes.

  In lift start method (touch start method) TIG welding, where the welding torch touches the workpiece (base material) and generates an arc when it is pulled apart, a small current is applied between the tip of the non-consumable electrode and the workpiece. A technique is known in which, after detecting that the tip of the electrode is in contact with the workpiece by, the arc is started by pulling away the non-consumable electrode with a normal current (see, for example, Patent Document 1).

  In addition, the arc welding time, number of arc starts, and wire consumption during arc welding are integrated and compared with a reference amount that serves as a guide for replacement timing. If the integrated value exceeds the reference amount, arc welding of the power supply tip, etc. There is also known a technique for notifying the replacement time of the consumable parts (see, for example, Patent Document 2).

JP 2000-176661 A JP 2009-172610 A

  Although it is possible to suppress the deformation of the electrode due to heat generation at the start current conduction by the method described in Patent Document 1, it is not possible to suppress the deformation of the electrode due to the contact at the time of touching, so the non-consumable electrode is periodically replaced. There is a need. In order to extend the replacement life, a method of reducing the consumption of the non-consumable electrode at the time of touching is also considered. In a normal method in which the non-consumable electrode is brought into contact with the workpiece in a direction perpendicular to the workpiece, the degree of deformation of the non-consumable electrode is increased. In view of this, a lift start method is also conceivable in which the deformation of the electrode tip can be suppressed by tilting the non-consumable electrode and touching the workpiece with the tapered portion.

Moreover, it is thought that the notification of the replacement time of the non-consumable electrode in TIG welding can be performed by using a method similar to the method described in Patent Document 2. However, as described above, when both the method of bringing the non-consumable electrode into contact with the work and the method of bringing the tapered portion of the non-consumable electrode into contact with the work are used, the appropriateness of the non-consumable electrode is used. There was a problem that notification of replacement time was difficult. For example, if the number of contact between the non-consumable electrode and the workpiece is simply counted and compared with a reference amount, if there is a lot of contact on the surface, deformation exceeding the replacement standard occurs in the non-consumable electrode. Despite this, it can happen that the non-consumable electrode is not replaced. Moreover, when there is much contact with a taper, it is possible to replace a non-consumable electrode that can still be used.
Generally speaking, in a welding robot that performs lift start by bringing a non-consumable electrode into contact with a workpiece by a plurality of contact methods, there has been a problem that an appropriate replacement timing of the non-consumable electrode cannot be notified.

  The present invention has been made to solve the above-mentioned problems, and appropriately notifies the replacement timing of the non-consumable electrode in a welding robot that performs lift start by bringing the non-consumable electrode into contact with the workpiece by a plurality of contact methods. An object of the present invention is to provide a welding electrode management apparatus that can perform the above-described process.

In order to achieve the above object, the welding electrode management apparatus according to the present invention determines which contact method is used in a welding robot that performs lift start by bringing a non-consumable electrode into contact with a base material by a plurality of contact methods. The contact determination unit to determine, the contact number update unit to update the number of contacts according to the contact method according to the determination result by the contact determination unit, and the threshold value used for determining the replacement of the non-consumable electrode are stored. By using the update result by the threshold storage unit and the contact number update unit, it is determined that the non-consumable electrode is replaced when the total number of contacts, which is the number of contacts weighted and added for each contact method, exceeds the threshold value And an output unit that outputs a message to that effect when the replacement determination unit determines to replace the non-consumable electrode.
With such a configuration, even when the non-consumable electrode and the base material are contacted by a plurality of contact methods, the degree of consumption of the non-consumable electrode can be properly grasped, and the non-consumable electrode can be replaced. It becomes possible to notify the time appropriately.

In the welding electrode management device according to the present invention, the contact number update unit updates the total contact number according to the determination result by the contact determination unit, and the replacement determination unit calculates the total contact number updated by the contact number update unit. Judgment may be made by using.
With such a configuration, every time contact between the non-consumable electrode and the base material is performed, the total number of contacts is updated according to the contact method, so it is not always necessary to manage the number of contacts for each contact method, The amount of information to be stored can be reduced.

Further, in the welding electrode management device according to the present invention, the contact frequency update unit updates the contact frequency for each contact method, and the replacement determination unit uses the contact frequency for each contact method updated by the contact frequency update unit. The contact count may be calculated, and the determination may be made using the calculated total contact count.
With such a configuration, since the number of times of contact for each contact method is also stored, for example, the number of times of contact for each contact method can be known.

Further, in the welding electrode management device according to the present invention, the plurality of contact methods are a method of bringing the non-consumable electrode into contact with the base material in a direction perpendicular to the base material, and a method of bringing the tapered portion of the non-consumable electrode into contact with the base material, In calculating the total number of contacts, the weight of the method of bringing the non-consumable electrode into contact with the base material in a direction perpendicular to the base material may be larger than the weight of the method of bringing the tapered portion of the non-consumable electrode into contact with the base material.
With such a configuration, in the lift start type welding using both the contact method in which the non-consumable electrode is brought into contact with the base material in a direction perpendicular to the base material and the contact method in which the tapered portion of the non-consumable electrode is brought into contact with the base material. This makes it possible to know the appropriate replacement time for the non-consumable electrode.

Further, in the welding electrode management apparatus according to the present invention, the contact determination unit also determines which region of the tapered portion is contacted when the tapered portion of the non-consumable electrode is in contact with the base material, and the contact is determined. The number updating unit updates the number of times of contact according to the contact method for each region of the tapered portion, and the replacement determining unit is when the total number of times of contact corresponding to any region of the tapered portion exceeds the threshold value, It may be determined that the non-consumable electrode is replaced.
With such a configuration, it becomes possible to determine the replacement timing of the non-consumable electrode more strictly, and for example, it is possible to avoid a situation where the non-consumable electrode that can still be used is replaced.

The welding electrode management device according to the present invention further includes an acquisition unit that acquires a parameter related to welding when the non-consumable electrode is in contact with the base material, and the contact number update unit is configured to respond to the parameter acquired by the acquisition unit. The number of contacts according to the contact method may be updated.
With such a configuration, the total number of contacts can be calculated more strictly using parameters related to welding.
In the welding electrode management apparatus according to the present invention, the parameter may be at least one of a welding current and a speed of the non-consumable electrode with respect to the base material.

  According to the welding electrode management device of the present invention, it is possible to appropriately notify the replacement time of the non-consumable electrode even when the non-consumable electrode and the base material are contacted by a plurality of contact methods. Become.

The figure which shows the structure of the welding robot system which has the welding electrode management apparatus by Embodiment 1 of this invention. The figure for demonstrating the contact of the non-consumable electrode in the orthogonal | vertical direction to the base material in the embodiment The figure for demonstrating the contact to the base material of the taper part of the non-consumable electrode in the embodiment The flowchart which shows operation | movement of the control apparatus which has the welding electrode management apparatus by the embodiment The figure for demonstrating the several area | region of the non-consumable electrode in the embodiment The figure which shows another example of a structure of the welding electrode management apparatus by the embodiment

  Hereinafter, a welding electrode management device according to the present invention will be described using embodiments. In the following embodiments, components and steps denoted by the same reference numerals are the same or equivalent, and repetitive description may be omitted.

(Embodiment 1)
A welding electrode management apparatus according to Embodiment 1 of the present invention will be described with reference to the drawings. The welding electrode management device according to the present embodiment can notify an appropriate replacement time of the non-consumable electrode.

  FIG. 1 is a block diagram showing a configuration of a welding robot system according to the present embodiment. The welding robot system according to the present embodiment is a welding robot system that performs lift start using a non-consumable electrode, and includes a control device 1, a manipulator 3, a welding power supply device 4, and a teaching pendant 5. The welding for performing the lift start using the non-consumable electrode may be, for example, TIG (Tungsten Inert Gas) welding.

The control device 1 includes a communication unit 11, a teaching information storage unit 12, a control unit 13, and a welding electrode management device 2.
The communication unit 11 transmits instructions such as welding start, welding end, filler wire feeding start, feeding end, and the like to the welding power source device 4 in accordance with instructions from the control unit 13. Moreover, the communication part 11 may receive the data acquired in a welding robot. The data acquired by the welding robot may be, for example, a voltage between the welding torch 3a and the base material 8. Note that the communication unit 11 may or may not include a wired or wireless communication device (for example, a modem or a network card) for performing communication.

  The teaching information storage unit 12 stores teaching information. The teaching information may be, for example, information indicating the position of each drive motor of the manipulator 3, information on the start or end of welding, output voltage, filler wire feeding, or the like. The teaching information storage unit 12 can be realized by a predetermined recording medium (for example, a semiconductor memory, a magnetic disk, an optical disk, etc.).

  The control unit 13 drives each of the manipulators 3 according to the teaching information stored in the teaching information storage unit 12, the operation signal input from the teaching pendant 5, the current position of the driving motor received from the encoder of the manipulator 3, and the like. Control the position of the motor. With this control, the welding torch 3a is moved to a desired position. In the control, the control unit 13 may control the manipulator 3 via a servo controller. The manipulator 3 may be controlled by outputting a position command value to the servo controller. In addition, the control unit 13 starts or ends welding by the welding power source device 4, starts output voltage, and feeds the filler wire via the communication unit 11 according to the teaching information stored in the teaching information storage unit 12. And control the end. The control related to the welding may be performed by outputting a current command value or the like corresponding to the welding condition to the welding power source device 4.

The welding electrode management device 2 includes a contact determination unit 21, a contact count update unit 22, a storage unit 23, a threshold storage unit 24, an exchange determination unit 25, and an output unit 26.
The contact determination unit 21 determines which contact method is used in the welding robot that performs lift start by bringing the non-consumable electrode into contact with the base material 8 by a plurality of contact methods. The plurality of contact methods include a method in which the non-consumable electrode is brought into contact with the base material 8 in a direction perpendicular to the base material 8 (hereinafter, also referred to as “surface direct contact method”), and a taper portion of the non-consumable electrode is formed in the base material 8. The method may be a method of contacting the surface (hereinafter also referred to as “taper contact method”). In the present embodiment, a case where a plurality of contact methods are the two methods will be mainly described. The tapered portion of the non-consumable electrode is a substantially conical portion near the tip of the non-consumable electrode.

  A method for the contact determination unit 21 to determine which contact between the surface direct contact method and the taper contact method has been performed will be described with reference to FIGS. 2A and 2B. FIG. 2A is a diagram for explaining a surface direct contact method, and FIG. 2B is a diagram for explaining a taper contact method. As shown in FIG. 2A, in the surface direct contact method, the length direction (axial direction) of the non-consumable electrode 3b is a direction perpendicular to the base material 8 (direction orthogonal to the surface of the base material 8). Yes. Further, the non-consumable electrode 3b moves in a direction perpendicular to the base material 8. Therefore, in the surface direct contact method, the tip 3 d of the non-consumable electrode 3 b comes into contact with the base material 8. Therefore, when the non-consumable electrode 3b is brought into contact with the base material 8 by the surface direct contact method, the moving direction of the non-consumable electrode 3b substantially coincides with the length direction of the non-consumable electrode 3b, and the movement in the tool coordinate system. The direction substantially coincides with the Z-axis direction. The tool coordinate system is a three-dimensional orthogonal coordinate system in which the length direction of the non-consumable electrode 3b is the Z-axis direction. On the other hand, as shown in FIG. 2B, in the taper contact method, the length direction of the non-consumable electrode 3 b is not a direction perpendicular to the base material 8, but the non-consumable electrode 3 b is straight to the base material 8. Move in the direction. Therefore, in the taper contact method, the tapered portion 3 c of the non-consumable electrode 3 b comes into contact with the base material 8. When the non-consumable electrode 3b is brought into contact with the base material 8 by the taper contact method, the moving direction of the non-consumable electrode 3b does not coincide with the length direction of the non-consumable electrode 3b, and the moving direction in the tool coordinate system is Does not match the Z-axis direction. Here, as shown in FIG. 2B, when the angle between the length direction of the non-consumable electrode 3b (Z-axis direction in the tool coordinate system) and the moving direction is θt, in the case of the surface direct contact method, θt is a small value, and in the case of the taper contact method, θt is a large value. Therefore, the contact determination unit 21 may determine that the contact is based on the surface direct contact method when θt <θth, and may determine that the contact is based on the taper contact method when θt> θth. When θt = θth, it may be determined that the contact is based on the surface direct contact method, or may be determined based on the taper contact method. θth is a predetermined threshold value used for determining the contact method. Needless to say, the method by which the contact determination unit 21 determines the contact method is not limited to the above method as long as it is substantially the same as the method described above. For example, the determination may be made using the world coordinate system without using the tool coordinate system. In this case, the contact determination unit 21 determines whether the angle formed by the length direction of the non-consumable electrode 3b and the movement direction of the non-consumable electrode 3b in the world coordinate system is greater than a threshold value θth, for example. It may be determined whether the contact is a direct contact method or a taper contact method. The threshold value θth may be stored on a recording medium (not shown).

The contact number update unit 22 updates the contact number according to the contact method according to the determination result by the contact determination unit 21. The update result is stored in the storage unit 23. Note that the contact count update unit 22 may update the total contact count according to the determination result by the contact determination unit 21. The total number of touches is the number of touches obtained by adding weights for each touch method. Therefore, for example, the total number of contacts may be as follows.
Total number of contacts = Number of direct surface contacts x L + Number of taper contacts (1)
Total number of contacts = number of direct surface contacts + number of taper contacts x K (Equation 2)
Total number of contacts = number of direct surface contacts x M1 + number of taper contacts x M2 (Equation 3)

  The number of times of surface direct contact is the number of contacts by the surface direct contact method, and the number of times of taper contact is the number of contacts by the taper contact method. L is a real number larger than 1, K is a positive real number smaller than 1, and M1 and M2 are positive real numbers such that M1> M2. Since the contact by the surface direct contact method has a greater influence (damage) on the non-consumable electrode 3b than the contact by the taper contact method, the weight of the surface direct contact method (weight of the number of surface direct contacts) ) Is set to a larger value than the weight of the taper contact method (weight of the number of times of taper contact). Note that the total number of contacts in Equation 1 is the number of contacts converted to the taper contact method. The total number of times of contact in Equation 2 is the number of times of contact converted to the number of times of direct contact with the surface. The total number of contacts in Equation 3 is the number of contacts converted to M1 times the number of surface direct contacts or M2 times the number of taper contacts. Thus, strictly speaking, the total number of contacts is not the number of contacts, but a score that increases as the number of contacts by each contact method increases.

  Therefore, when the total contact number is Equation 3, the contact number update unit 22 increments the total contact number by M1 when the contact by the surface direct contact method is performed, and the contact by the taper contact method is performed. The total number of touches is incremented by M2. When the total number of times of contact is calculated by Equation 1, M1 = L and M2 = 1. Further, when the total number of times of contact is calculated by Equation 2, M1 = 1 and M2 = K.

  Further, the total number of contacts is preferably reset (usually set to 0) when the non-consumable electrode 3b is replaced. Therefore, when the non-consumable electrode 3b is replaced, the contact number updating unit 22 may reset the total number of contacts stored in the storage unit 23.

  In the storage unit 23, the total number of contact times updated by the contact number update unit 22 is stored. The storage in the storage unit 23 may be temporary storage in a RAM or the like, or may be long-term storage. The storage unit 23 can be realized by a predetermined recording medium (for example, a semiconductor memory, a magnetic disk, an optical disk, etc.). Since the total number of contacts stored in the storage unit 23 needs to be held until the non-consumable electrode 3b is replaced, the storage unit 23 is a non-volatile recording medium that can perform long-term storage. It is preferable to be realized by.

  The threshold value storage unit 24 stores a threshold value used for determination of replacement of the non-consumable electrode 3b. As will be described later, this threshold is a threshold that is compared with the total number of touches. For example, when the total contact number is calculated using Equation 1, the threshold may be a value obtained by multiplying the contact upper limit number Nth by the surface direct contact method by L, and the total contact number using Equation 2. May be Nth, and when calculating the total number of times of contact using Equation 3, a value obtained by multiplying Nth by M1 may be used. The threshold value storage unit 24 is usually capable of long-term storage. The threshold storage unit 24 can be realized by a predetermined recording medium (for example, a semiconductor memory, a magnetic disk, an optical disk, etc.). The threshold storage unit 24 is preferably realized by a nonvolatile recording medium that can perform long-term storage.

  The replacement determination unit 25 determines to replace the non-consumable electrode 3b when the total number of contacts exceeds the threshold by using the update result from the contact number update unit 22. Specifically, the exchange determination unit 25 determines that the total contact count stored in the storage unit 23, that is, the total contact count updated by the contact count update unit 22 is greater than the threshold stored in the threshold storage unit 24. If it is larger, it is determined that the non-consumable electrode 3b is replaced. When the total number of contacts is equal to the threshold value, the replacement determination unit 25 may determine that the non-consumable electrode 3b is to be replaced or not. Further, since it is determined that the non-consumable electrode 3b is replaced when the total number of contacts is larger than the threshold, the determination that the non-consumable electrode 3b is replaced is determined that the total number of contacts is larger than the threshold. You may think that

  When the replacement determination unit 25 determines to replace the non-consumable electrode 3b, the output unit 26 outputs that effect. As a result of the output, the user of the welding robot system can know that the non-consumable electrode 3b has come to be replaced. The output may be anything as long as it can prompt the user of the welding robot system to replace the non-consumable electrode 3b. Here, the output may be, for example, display on a display device (for example, a liquid crystal display), transmission via a communication line to a predetermined device, printing by a printer, or audio output by a speaker. It may be stored in a recording medium or delivered to another component. When the replacement determination unit 25 determines that the non-consumable electrode 3b is to be replaced, the output unit 26 may turn on a lamp for informing the replacement of the non-consumable electrode 3b. "Please replace the electrode" or "Please replace the electrode" may be output, and other voices such as "Please replace the electrode" may be output. Output may be performed. In the present embodiment, when the replacement determination unit 25 determines to replace the non-consumable electrode 3b, the output unit 26 passes information for prompting replacement of the non-consumable electrode 3b to the teaching pendant 5, and the teaching pendant 5 The information is output. The output in the teaching pendant 5 may be a display, for example. Note that the output unit 26 may or may not include an output device (for example, a display device or a printer). The output unit 26 may be realized by hardware, or may be realized by software such as a driver that drives these devices.

  Note that the storage unit 23 and the threshold storage unit 24 may be realized by the same recording medium or may be realized by separate recording media. In the former case, the area storing the updated total number of contacts is the storage unit 23, and the area storing the threshold is the threshold storage unit 24.

  In the present embodiment, the case where the control device 1 includes the welding electrode management device 2 will be mainly described, but this need not be the case. For example, the welding electrode management device 2 may exist outside the control device 1. In that case, for example, the contact determination unit 21 of the welding electrode management device 2 receives a command or the like output to the manipulator 3 or the welding power source device 4 from the control unit 13 of the control device 1, and receives the received command or the like. The contact method may be used to make a determination.

  The manipulator 3 has a plurality of arms connected by joints driven by a drive motor via a speed reducer. The drive motor may include an encoder, and the current position of the drive motor may be detected by the encoder. A welding torch 3 a that performs arc welding on the base material 8 is attached to the tip of the manipulator 3. The welding torch 3a has a non-consumable electrode 3b. An arc is generated when a high voltage is applied between the non-consumable electrode 3b of the welding torch 3a and the base material 8 by the welding power source device 4, and the base material 8 is melted by the heat of the arc. Thus, welding on the base material 8 is performed. In addition, the structure of the manipulator 3 is already well-known, The detailed description is abbreviate | omitted. Moreover, in TIG welding, it is common to supply a filler wire to a location where the base material 8 is melted by the generated arc, but the description of the configuration for supplying the filler wire is omitted. In TIG welding, a shield gas that is an inert gas such as helium or argon is generally ejected from the welding torch 3a, but a description of the configuration for ejecting the inert gas is omitted.

  The welding power source device 4 includes a welding power source that supplies a high voltage used in welding to the welding torch 3a and the base material 8, a welding control unit that controls the welding power source according to the welding conditions transmitted from the control device 1, and the like. I have. Moreover, the welding power supply device 4 may include a wire feed control unit that controls feeding of the filler wire. In addition, the structure of the welding power supply device 4 is already well-known, The detailed description is abbreviate | omitted.

  The teaching pendant 5 is a terminal used for teaching the welding robot, and may pass an operation signal or the like according to the operation of the operator to the control device 1. Moreover, the information from the control apparatus 1 may be received and output to a display or the like. The output may be, for example, an output for informing the replacement of the non-consumable electrode 3b. Note that an operation instruction or the like input from the teaching pendant 5 to the control device 1 may be passed to the control unit 13 via a route (not shown). Further, teaching information may be accumulated in the teaching information storage unit 12 in accordance with an operation instruction input from the teaching pendant 5 to the control device 1. Further, a setting value such as a threshold value stored in the threshold value storage unit 24 may be set by the teaching pendant 5.

  In the present embodiment, the case where the control device 1 controls one manipulator 3 and one welding power source device 4 has been described, but this need not be the case. The control device 1 may control a plurality of manipulators 3 and a plurality of welding power supply devices 4. Therefore, the welding electrode management device 2 may make a determination regarding replacement of the non-consumable electrodes 3b regarding a plurality of welding robots. In such a case, it is preferable that each component of the welding electrode management device 2 performs each process such as a determination process and an update process for each non-consumable electrode 3b.

  Next, operation | movement of the control apparatus 1 is demonstrated using the flowchart of FIG. In this flowchart, the case where the total number of contacts is calculated according to the above-described equation 1 will be described.

  (Step S101) The control unit 13 reads the teaching information from the teaching information storage unit 12, and accumulates each teaching step corresponding to the teaching information in a queue (not shown) of the control unit 13. In the accumulation, for example, the control unit 13 analyzes teaching information, accumulates welding conditions including current commands in the queue in the case of a welding command, and stores each axis of the manipulator 3 in the case of a movement command. The angle and the moving direction in the tool coordinate system may also be accumulated in the queue.

  (Step S102) The controller 13 substitutes the value at the head of the queue for the pointer ptr.

  (Step S103) The control unit 13 reads the teaching step of the pointer ptr from the queue.

  (Step S104) In step S103, the control unit 13 determines whether or not the teaching step of the pointer ptr has been read from the queue. If read, the process proceeds to step S105. If not read (if the read teaching step is Null), all the teaching steps accumulated in the queue have been executed. A series of processes corresponding to the teaching information is completed.

  (Step S105) The control unit 13 determines whether or not the teaching step read in step S103 is a movement command. If it is a movement command, the process proceeds to step S106, and if not, the process proceeds to step S117.

  (Step S106) The control unit 13 decrements the pointer ptr by 1.

  (Step S107) The control unit 13 determines whether or not the teaching step of the pointer ptr is a touch command. And if it is a touch command, it will progress to step S108, and if that is not right, it will progress to step S114. The touch command is to apply a predetermined voltage between the non-consumable electrode 3b and the base material 8 in order to determine whether or not the non-consumable electrode 3b is in contact with the base material 8. When the voltage becomes 0, it can be determined that both are in contact. Therefore, when the movement command that is the teaching step read in step S103 is a movement command subsequent to the touch command, it is understood that the movement command is for bringing the non-consumable electrode 3b into contact with the base material 8.

  (Step S108) The control unit 13 passes the angle θt formed by the Z axis in the tool coordinate system and the movement direction in the movement command read out in step S103 to the contact determination unit 21.

  (Step S109) The contact determination unit 21 reads θth from a recording medium (not shown) and determines whether θt is equal to or smaller than θth. If θt is equal to or smaller than θth, it is determined that contact by the surface direct contact method is performed, and the process proceeds to step S110. Otherwise, it is determined that contact by the taper contact method is performed, and step S111 is performed. Proceed to

  (Step S110) The contact count updating unit 22 adds L to the total contact count stored in the storage unit 23. That is, the total number of times of contact according to the contact by the surface direct contact method is updated.

  (Step S <b> 111) The contact count updating unit 22 adds 1 to the total contact count stored in the storage unit 23. That is, the total number of contacts is updated according to the contact by the taper contact method.

  (Step S112) The exchange determination unit 25 reads the updated total contact count from the storage unit 23, reads the threshold value from the threshold storage unit 24, and determines whether the total contact count is equal to or greater than the threshold value. If it is equal to or greater than the threshold value, the fact is passed to the output unit 26 and the process proceeds to step S113. Otherwise, the process proceeds to step S114.

  (Step S113) The output unit 26 outputs that the non-consumable electrode 3b is to be replaced.

  (Step S114) The control unit 13 increments the pointer ptr by one. By this increment, the pointer ptr decremented in step S106 is restored.

  (Step S115) The controller 13 notifies the servo controller of a movement command. As a result, the manipulator 3 operates according to the movement command.

  (Step S116) The control unit 13 increments the pointer ptr by 1 and returns to step S103.

  (Step S117) The control unit 13 notifies the welding power source device 4 of a welding command or a touch command. Then, the process proceeds to step S116.

  Note that the order of processing in the flowchart of FIG. 3 is an example, and the order of each step may be changed as long as similar results can be obtained. For example, in the flowchart of FIG. 3, the case where the movement command is notified after the contact method determination processing or the like (steps S <b> 106 to S <b> 114) has been described, the notification of the movement command is performed in steps S <b> 105 and S <b> 106. It may be performed between the processes. As a result, if it is possible to update the total number of times of contact and to notify the replacement of the non-consumable electrode 3b using the updated total number of times of contact, the control device 1 performs processing other than the flowchart of FIG. It goes without saying that may be done. For example, the contact determination unit 21 refers to the teaching information stored in the teaching information storage unit 12 or the teaching steps queued by the control unit 13, and the contact by which contact method is performed before each step is executed. It may be judged whether it is performed. And when the contact by the contact method is actually performed, the contact frequency update part 22 may update the total contact frequency according to the contact method determined in advance. Further, even when the threshold value stored in the threshold value storage unit 24 is changed, the processes in steps S112 and S113 may be performed. That is, when the total number of contacts at that time is larger than the changed threshold value, a message that the non-consumable electrode 3b is to be replaced may be output.

Next, the operation of the control device 1 according to the present embodiment will be described using a specific example. Also in this specific example, it is assumed that the total number of times of contact is calculated according to the above-described formula 1.
First, the control unit 13 reads out and analyzes the teaching information stored in the teaching information storage unit 12, generates each teaching step, and queues the teaching step (step S101). Thereafter, the first teaching step is read out, and it is determined whether or not the teaching step is a movement command (steps S102 to S105). Here, it is assumed that the teaching step is a movement command. Then, the control unit 13 determines whether or not the teaching step immediately before the teaching step is a touch command (steps S106 and S107). Here, since there is no previous teaching step, the control unit 13 notifies the servo controller of the movement command (steps S114 and S115). As a result, the manipulator 3 moves according to the movement command.

  Next, the control unit 13 reads the second teaching step and determines whether or not the teaching step is a movement command (steps S116, S103 to S105). Here, it is assumed that the teaching step is a touch command. Then, the control part 13 notifies the welding power supply device 4 of the touch command (step S117). As a result, a predetermined voltage is applied between the non-consumable electrode 3b and the base material 8 in accordance with the touch command.

  Thereafter, the control unit 13 reads out the third teaching step and determines whether or not the teaching step is a movement command (steps S116 and S103 to S105). Here, it is assumed that the teaching step is a movement command. Then, the control unit 13 determines whether or not the teaching step immediately before the teaching step is a touch command (steps S106 and S107). Here, since the previous teaching step is a touch command, the control unit 13 determines the angle θt formed by the Z axis in the tool coordinate system in the movement command and the movement direction according to the movement command as a contact determination unit. 21 (step S108). When receiving the angle θt, the contact determination unit 21 determines whether the angle is equal to or smaller than θth (step S109). Here, it is assumed that the angle θt is equal to or smaller than θth. Then, the contact determination part 21 passes to the contact frequency update part 22 that the contact by the surface direct contact method was performed. Then, the contact number updating unit 22 updates the total contact number by adding L to the total contact number stored in the storage unit 23 (step S110). When it is detected that the update has been performed, the exchange determination unit 25 reads the total contact count from the storage unit 23, reads the threshold value from the threshold storage unit 24, and determines whether the total contact count is equal to or greater than the threshold (step). S112). Here, it is assumed that the total number of contacts is equal to the threshold value. Then, the exchange determination unit 25 passes to the output unit 26 that notification of exchange is performed. When receiving the notification of replacement from the replacement determination unit 25, the output unit 26 outputs a notification of replacing the non-consumable electrode 3b to the teaching pendant 5 (step S113). In response to the output, the display of the teaching pendant 5 displays “Non-consumable electrode replacement time”, and the operator of the teaching pendant 5 indicates that the non-consumable electrode 3b of the welding robot has been replaced. You can know that In this case, the operator may temporarily stop the welding robot and replace the non-consumable electrode 3b, or wait until a good point of separation or a series of processing ends, and then wait for the non-consumable electrode 3b. 3b may be exchanged. When the non-consumable electrode 3b is replaced, the total number of contacts stored in the storage unit 23 is reset as described above.

  As described above, according to the welding electrode management device 2 according to the present embodiment, even when the non-consumable electrode 3b and the base material 8 are contacted by a plurality of contact methods, the non-consumable electrode 3b is consumed. Can be managed accurately. As a result, it becomes possible to appropriately know the replacement time of the non-consumable electrode 3b, to replace the non-consumable electrode 3b that can still be used, or to continue the non-consumable electrode 3b in which the deformation exceeds the replacement standard. Can be avoided. Therefore, it is possible to achieve both cost reduction and high-quality welding.

  In the present embodiment, the case where the plurality of contact methods are the surface direct contact method and the taper contact method has been described. Needless to say, the plurality of contact methods may be other than those. Even in such a case, an appropriate replacement time for the non-consumable electrode 3b is grasped by calculating the total number of times of contact in consideration of the degree of wear and deformation of the non-consumable electrode 3b according to each contact method. Will be able to.

  In the present embodiment, the case where the contact number updating unit 22 calculates the total contact number has been described, but this need not be the case. The contact count update unit 22 may update the contact count for each contact method. In that case, the number of contacts for each contact method is stored in the storage unit 23. That is, in that case, the update of the number of contacts according to the contact method is an update of the number of contacts for each contact method, and the update result stored in the storage unit 23 is the number of contacts for each contact method. For example, when the plurality of contact methods are the surface direct contact method and the taper contact method, the storage unit 23 may store the number of contacts in the surface direct contact method and the number of contacts in the taper contact method. . In addition, when the contact frequency update unit 22 updates the contact frequency for each contact method, the exchange determination unit 25 calculates the total contact frequency using the contact frequency for each contact method updated by the contact frequency update unit 22. May be. Then, the replacement determination unit 25 may determine whether or not the total contact count exceeds a threshold using the calculated total contact count. The calculation of the total number of times of contact may be performed using, for example, any one of Equations 1 to 3 as described above. That is, the exchange determination unit 25 reads the calculation formula for the total contact number stored in a recording medium (not shown), reads the contact number for each contact method stored in the storage unit 23, and calculates the contact number as the total contact number. The total number of contacts may be calculated by substituting into the equation. In this case, the output unit 26 may output the number of times of contact for each contact method stored in the storage unit 23. For example, the output enables the operator of the welding robot to know how much contact has been made by each contact method.

  Moreover, although this Embodiment demonstrated the case where the contact by a taper contact method was performed, the contact was counted as one contact of the taper part 3c, it does not need to be so. When contact is made by the taper contact method, the contact is counted as one contact in the region of the tapered portion 3c where contact has been made, and the total number of contacts corresponding to each region is compared with a threshold value, thereby reducing consumption. You may make it judge the replacement | exchange time of the electrode 3b. This is because it is considered that the influence of contact in a certain region of the tapered portion 3c on other regions of the tapered portion 3c is small. Therefore, when the tapered portion 3c of the non-consumable electrode 3b is brought into contact with the base material 8, the contact determining unit 21 may determine which region of the tapered portion 3c is in contact. And the contact frequency update part 22 may update the contact frequency according to the contact method for every area | region of the taper part 3c. Further, the replacement determination unit 25 may determine to replace the non-consumable electrode 3b when the total number of contacts corresponding to any region of the tapered portion 3c exceeds a threshold value. By doing in this way, it is possible to determine the replacement time of the non-consumable electrode 3b more accurately.

  The number of regions of the tapered portion 3c is not particularly limited, but may be two, three, four, or more, for example. When the number of regions is large, each region is narrowed, and the influence of contact in a certain region on adjacent regions is increased. Therefore, it is preferable that the number of the regions is not too large. Moreover, it is preferable that the size of each region is equal. Further, each region may be a region in which the tapered portion 3c is divided by a line segment extending from the tip 3d of the non-consumable electrode 3b to the side surface of the non-consumable electrode 3b, as shown in FIG. In the case of FIG. 4, the taper portion 3c is divided into four regions 3c-1 to 3c-4. FIG. 4 is a view of the non-consumable electrode 3b as viewed from the tip 3d. Therefore, the length direction of the non-consumable electrode 3b is a direction perpendicular to the paper surface of FIG.

When the tapered portion 3c is divided as shown in FIG. 4, for example, the contact count updating unit 22 may update the total contact count of each region using the following formula. The following expression corresponds to the above-described expression 3. However, when M2 = 1, the expression corresponds to the above-described expression 1, and when M1 = 1, the expression corresponds to the above-described expression 2. It becomes.
Total number of contact in region 3c-1 = Number of surface direct contact × M1 + Number of taper contact in region 3c-1 × M2
Total number of contact in region 3c-2 = Number of surface direct contact × M1 + Number of taper contact in region 3c-2 × M2
Total number of contact in region 3c-3 = Number of surface direct contact × M1 + Number of taper contact in region 3c-3 × M2
Total number of contact in region 3c-4 = number of surface direct contact × M1 + number of taper contact in region 3c-4 × M2

  Therefore, for example, when the contact determination unit 21 determines that the contact by the taper contact method is performed in the region 3c-3, the contact number update unit 22 increments the total contact number of the region 3c-3 by M2. May be. Further, as described above, the exchange determination unit 25 uses the total contact count for each region, which is a result of the increment as described above, so that the total contact count corresponding to any region exceeds the threshold value. In this case, it is determined that the non-consumable electrode 3b is replaced. Therefore, in this case, it is possible to extend the life of the non-consumable electrode 3b by generating the teaching information so that the number of times of contact of each region of the tapered portion 3c of the non-consumable electrode 3b is as uniform as possible.

  When contact is made by the taper contact method, the contact determination unit 21 can calculate which position of the non-consumable electrode 3b is in contact with the base material 8 by using a movement command. Therefore, by using the position, the contact determination unit 21 can determine in which region the contact has been made. Specifically, for example, when the contact position is represented in the tool coordinate system, when the contact position is in the Nth quadrant on the XY plane, the contact determination unit 21 performs the taper contact in the region 3c-N. You may judge that the contact by the method was performed. N is an integer of 1 to 4.

  Further, even when the determination or the like is performed for each region of the tapered portion 3c in this way, the contact number update unit 22 may update the total contact number for each region 3c-1 to 3c-4. You may update the contact frequency and the taper contact frequency for every area | region 3c-1 to 3c-4. In the latter case, the total number of contacts for each of the areas 3c-1 to 3c-4 may be calculated by the replacement determination unit 25.

  Moreover, although this Embodiment demonstrated the case where the update by the contact frequency update part 22 was performed irrespective of the parameter regarding welding, it does not need to be so. Hereinafter, the case where the update by the contact frequency update part 22 is performed also using the parameter regarding welding is demonstrated using FIG. In FIG. 5, the welding electrode management device 2 includes a contact determination unit 21, a contact frequency update unit 22, a storage unit 23, a threshold storage unit 24, an exchange determination unit 25, an output unit 26, and an acquisition unit 27. Is provided. The configuration and operation other than the acquisition unit 27 are the same as those described above except that the contact number update unit 22 performs the update using the welding-related parameters acquired by the acquisition unit 27, and the description thereof is omitted.

  The acquisition unit 27 acquires parameters related to welding when the non-consumable electrode 3b is in contact with the base material 8. The parameter is not particularly limited, and may be, for example, at least one of a welding current and a speed of the non-consumable electrode 3b with respect to the base material 8. For example, the acquisition unit 27 may acquire the welding current from the teaching information, or may acquire the welding current by receiving the welding current measured in the welding power source device 4. Moreover, the acquisition part 27 may acquire the speed with respect to the base material 8 of the non-consumable electrode 3b from teaching information, for example.

  The contact frequency update unit 22 updates the contact frequency according to the contact method according to the parameter acquired by the acquisition unit 27. For example, when the welding current is acquired, the contact frequency update unit 22 performs the update so that the degree of increment corresponding to the contact increases as the welding current increases. Further, when the speed is acquired, the contact count update unit 22 performs the update so that the greater the speed, the greater the increment according to the contact. This is because the larger the welding current, the greater the influence on the non-consumable electrode 3b at the time of contact, and the larger the speed, the greater the influence on the non-consumable electrode 3b at the time of contact. Specifically, when the welding current acquired by the acquisition unit 27 is larger than the welding current threshold, the contact number update unit 22 increments the total number of contacts and the number of contacts for each contact method. The increment amount (for example, M1 or M2 in the above-described expression 3) is incremented by A1, and when the welding current is smaller than the threshold value, the increment may be performed as usual. In addition, for example, when the speed acquired by the acquisition unit 27 is larger than the speed threshold, the contact count update unit 22 sets the increment amount when incrementing the total contact count or the contact count for each contact method. If the speed is smaller than the threshold value, it may be incremented as usual. Note that A1 and A2 are usually real numbers larger than one. Since A1 and A2 are for correcting the increment amount, it is preferable that they are not too large. For example, A1, A2, etc. may be 1.1, 1.2, 1.3, etc.

  In the above embodiment, each process or each function may be realized by centralized processing by a single device or a single system, or may be distributedly processed by a plurality of devices or a plurality of systems. It may be realized by doing.

  In the above embodiment, the information exchange between the components is performed by one component when, for example, the two components that exchange the information are physically different from each other. It may be performed by outputting information and receiving information by the other component, or when two components that exchange information are physically the same, one component May be performed by moving from the phase of the process corresponding to to the phase of the process corresponding to the other component.

  In the above embodiment, information related to processing executed by each component, for example, information received, acquired, selected, generated, transmitted, or received by each component In addition, information such as threshold values, mathematical formulas, addresses, and the like used by each component in processing may be temporarily or for a long time held in a recording medium (not shown), even if not specified in the above description. Further, the storage of information in the recording medium (not shown) may be performed by each component or a storage unit (not shown). Further, reading of information from the recording medium (not shown) may be performed by each component or a reading unit (not shown).

  In the above embodiment, when information used by each component, for example, information such as a threshold value, a mathematical expression, an address, and various setting values used by each component may be changed by the user. Even if not specified in the above description, the user may be able to change the information as appropriate, or may not be so. If the information can be changed by the user, the change is realized by, for example, a not-shown receiving unit that receives a change instruction from the user and a changing unit (not shown) that changes the information in accordance with the change instruction. May be. The change instruction received by the receiving unit (not shown) may be received from an input device, information received via a communication line, or information read from a predetermined recording medium, for example. .

  Moreover, in the said embodiment, when two or more components contained in the welding electrode management apparatus 2 have a communication device, an input device, etc., two or more components have a single device physically. Or may have separate devices.

  In the above embodiment, each component may be configured by dedicated hardware, or a component that can be realized by software may be realized by executing a program. For example, each component can be realized by a program execution unit such as a CPU reading and executing a software program recorded on a recording medium such as a hard disk or a semiconductor memory. At the time of execution, the program execution unit may execute the program while accessing the storage unit or the recording medium. The program may be executed by being downloaded from a server or the like, or may be executed by reading a program recorded on a predetermined recording medium (for example, an optical disk, a magnetic disk, a semiconductor memory, or the like). Good. Further, this program may be used as a program constituting a program product. Further, the computer that executes the program may be singular or plural. That is, centralized processing may be performed, or distributed processing may be performed.

  Further, the present invention is not limited to the above-described embodiment, and various modifications are possible, and it goes without saying that these are also included in the scope of the present invention.

  As described above, according to the welding electrode management device of the present invention, the effect that it is possible to appropriately notify the replacement timing of the non-consumable electrode in the welding robot is obtained, and it is useful as, for example, a device incorporated in a control device for a welding robot. .

DESCRIPTION OF SYMBOLS 1 Control apparatus 2 Welding electrode management apparatus 3b Non-consumable electrode 3c Taper part 4 Welding power supply device 8 Base material 11 Communication part 12 Teaching information storage part 13 Control part 21 Contact judgment part 22 Contact frequency update part 23 Storage part 24 Threshold storage part 25 Exchange determination unit 26 Output unit 27 Acquisition unit

Claims (7)

In a welding robot that performs lift start by bringing a non-consumable electrode into contact with a base material by a plurality of contact methods, a contact determination unit that determines which contact method is used for contact, and
According to a determination result by the contact determination unit, a contact number update unit that updates a contact number according to a contact method;
A threshold value storage unit for storing a threshold value used for determination of replacement of the non-consumable electrode;
By using the update result by the contact frequency update unit, an exchange determination that determines that the non-consumable electrode is to be replaced when the total number of contacts, which is the number of contacts weighted and added for each contact method, exceeds the threshold value And
A welding electrode management apparatus comprising: an output unit that outputs a message to the effect that the replacement determination unit determines to replace a non-consumable electrode. The contact number update unit updates the total contact number according to a determination result by the contact determination unit,
The welding electrode management device according to claim 1, wherein the replacement determination unit performs the determination using the total contact number updated by the contact number update unit. The contact number update unit updates the contact number for each contact method,
The said exchange determination part calculates the said total contact frequency using the contact frequency for every contact method updated by the said contact frequency update part, and performs the said determination using the calculated total contact frequency. Welding electrode management device. The plurality of contact methods are a method of bringing the non-consumable electrode into contact with the base material in a direction perpendicular to the base material, and a method of bringing the tapered portion of the non-consumable electrode into contact with the base material,
In the calculation of the total number of contacts, the weight of the method of bringing the non-consumable electrode into contact with the base material in a direction perpendicular to the base material is greater than the weight of the method of bringing the tapered portion of the non-consumable electrode into contact with the base material. The welding electrode management device according to any one of claims 1 to 3. The contact determination unit also determines which region of the tapered portion is contacted when the tapered portion of the non-consumable electrode is in contact with the base material,
The contact frequency update unit updates the contact frequency according to the contact method for each region of the tapered portion,
The welding electrode management apparatus according to claim 4, wherein the replacement determination unit determines to replace the non-consumable electrode when the total number of contacts corresponding to any region of the tapered portion exceeds the threshold value. It further includes an acquisition unit that acquires parameters related to welding when the non-consumable electrode contacts the base material,
The welding electrode management device according to any one of claims 1 to 5, wherein the contact number update unit updates the number of contacts according to a contact method according to the parameter acquired by the acquisition unit. The welding electrode management apparatus according to claim 6, wherein the parameter is at least one of a welding current and a speed of a non-consumable electrode with respect to a base material.

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