JP7046365B2 - Welding equipment and plate thickness inspection method for welding equipment - Google Patents

Description

The technique disclosed herein belongs to the technical field relating to a welding device and a method for inspecting the plate thickness of the welding device.

Conventionally, a welding device including a servo gun having a fixed electrode and a movable electrode has been known (for example, Patent Document 1). In this welding device, the distance between the electrodes is one factor for determining the welding conditions and the like. Therefore, many of the welding devices have a function of measuring the distance between the electrodes.

For example, in the welding apparatus described in Patent Document 1, a spot having a first electrode (movable electrode) on the gun shaft side driven by a servomotor and a second electrode (fixed electrode) fixed to the tip of the gun arm. In a spot welding device equipped with a welding gun, the movement amount of the first electrode is detected according to the detection signal of the rotary encoder that detects the rotation amount of the servo motor, and both electrodes are detected according to the movement amount of the first electrode. It is disclosed to detect the interval between.

Japanese Patent Application Laid-Open No. 2002-35951

By the way, if the distance between the electrodes can be measured as described in Patent Document 1, it is possible to measure the plate thickness of the object to be welded. For example, the plate thickness of the work piece can be measured by the amount of movement when the fixed electrode is in contact with one surface of the work piece and the movable electrode is moved until it comes into contact with the other side of the work piece. can. If the plate thickness of the work piece can be measured in this way, it is possible to detect whether or not the plate thickness of the work piece is correct, that is, whether or not a member having a plate thickness different from the desired member is erroneously welded. can do.

However, when the electrode is worn and worn, the amount of movement of the movable electrode until it comes into contact with the workpiece changes, so that the above-mentioned plate thickness inspection may not be performed normally.

On the other hand, for example, before actually performing the welding work of the workpiece, it is conceivable to confirm whether or not the plate thickness inspection is normally performed by using a dummy work imitating the workpiece. .. However, it is necessary to prepare a dummy work for each type of welded object, which increases the cost and requires expansion of the work space in order to secure a storage place. In addition, it is necessary to set an inspection standard for each dummy work, and it is necessary to put the dummy work on the production line for inspection, which may lead to deterioration of work efficiency.

The technique disclosed here has been made in view of these points, and the purpose thereof is whether or not the plate thickness inspection is normally performed in a welding device capable of inspecting the plate thickness of the work. The purpose is to make it possible to check efficiently at low cost while reducing the work space.

In order to solve the above problems, the first aspect of the technique disclosed herein is to provide a servo gun having a fixed electrode and a movable electrode, and to sandwich the object to be inspected between the fixed electrode and the movable electrode. For a welding device capable of inspecting the plate thickness of the inspected object, the thickness of the inspected object is calculated from the movement amount of the movable electrode with respect to the gun control unit that controls the operation of the servo gun and the fixed electrode. The calculation result is that the detection unit that detects an abnormality when the plate thickness is thinner than a predetermined amount or thicker than the predetermined amount with respect to the desired plate thickness, and the plate of the object to be inspected using the detection unit. A first determination unit that determines whether or not the thickness inspection is normally performed, and a first plate that is fixed at a jig fixing position in the space and has a plate thickness that is thinner than the predetermined amount with respect to a preset specific plate thickness. When a plate-shaped jig having a plate portion and a second plate portion having a plate thickness thicker than the predetermined amount with respect to the specific plate thickness is provided, and the gun control unit makes a determination by the determination unit. In addition, the servo gun is operated to measure the plate thickness of the first plate portion and the plate thickness of the second plate portion, and the determination unit determines the desired plate thickness to be the specified plate. When the detection unit inspects the plate thickness of the first and second plate portions as the thickness, and the detection unit detects an abnormality in each inspection, it is determined that the plate thickness inspection is normally performed. On the other hand, when the detection unit does not detect an abnormality in at least one of the inspections, it is determined that there is a defect in the plate thickness inspection.

A second aspect of the technique disclosed herein is characterized in that, in the first aspect, the jig further has a reference plate portion whose plate thickness is set to the specific plate thickness.

A third aspect of the technique disclosed herein is, in the first or second aspect, a robot having a plurality of arms and to which the servo gun is attached, and a robot control unit for operating and controlling the robot. Further, the jig is provided with at least the first and second plates by forming a step on the other side while one of the two surfaces in the plate thickness direction is a flat surface. The robot control unit is fixed so that the plate thickness direction is horizontal or vertical, and the robot control unit is located at a predetermined standby position at least when the production line is not in operation. When the robot is operated as described above and the plate thicknesses of the first and second plate portions are measured, the servo gun is moved from the standby position so that the fixed electrode is located on the one side in the plate thickness direction. It is characterized in that it is configured to operate the robot so as to move it to the jig fixing position.

A fourth aspect of the technique disclosed herein is characterized in that the jig has a Rockwell hardness HRC of 60 or greater.

The technique disclosed herein also covers a plate thickness inspection method for welding equipment. Specifically, a fifth aspect of the technique disclosed herein is to sandwich an object to be inspected between the fixed electrode and the movable electrode in a welding apparatus including a servo gun having a fixed electrode and a movable electrode. For the plate thickness inspection method of the welding apparatus for inspecting the plate thickness of the object to be inspected, the welding apparatus is fixed at a jig fixing position in the space and has a predetermined amount with respect to a predetermined specific plate thickness. A plate-shaped jig having a first plate portion having a thinner plate thickness and a second plate portion having a plate thickness thicker than a predetermined amount with respect to the specific plate thickness is further provided, and a plate thickness inspection by the welding apparatus is provided. As a step of determining whether or not is normally performed, the first measuring step of sandwiching the first plate portion between the fixed electrode and the movable electrode and measuring the plate thickness of the first plate portion. Based on the measurement results of the first measurement step, the first detection step of detecting an abnormality in the plate thickness and the second plate portion are sandwiched between the fixed electrode and the movable electrode, and the second plate portion is sandwiched between the fixed electrode and the movable electrode. The first and second detection steps include a second measurement step of measuring the plate thickness and a second detection step of detecting an abnormality in the plate thickness based on the measurement result of the second measurement step. It is a step of detecting an abnormality when the plate thickness is thinner than a predetermined amount or thicker than the predetermined amount with respect to the specific plate thickness, and the determination step is a step of detecting both the first and second detection steps. When an abnormality is detected in, it is determined that the plate thickness inspection is normally performed, while when no abnormality is detected in at least one of the first and second detection steps, the plate thickness inspection is performed. It is characterized in that it is a process of determining that there is a defect.

According to the first and fifth aspects of the technique disclosed herein, only by inspecting the plate thickness of the plate-shaped jig fixed at the jig fixing position, the plate thickness inspection using the detection unit is normally performed. Since it is possible to confirm whether or not the work has been performed, deterioration of work efficiency can be suppressed. In particular, since the same jig is used, it is not necessary to change the inspection standard, so that improvement in work efficiency can be expected.

Further, both the first plate portion having a plate thickness thinner than a predetermined amount with respect to the specific plate thickness and the second plate portion having a plate thickness thicker than a predetermined amount with respect to the specific plate thickness are measured to measure the plate thickness. In order to determine whether or not the inspection is performed normally, it is possible to confirm the plate thickness inspection both when the plate thickness is thin and when the plate thickness is thick. Therefore, high determination accuracy can be obtained.

Further, unlike the conventional case, it is not necessary to facilitate a large number of dummy works, and one plate-shaped jig may be prepared, so that the work space can be reduced and the cost can be reduced.

According to the second aspect of the technique disclosed herein, when there is a defect in the detection unit, calibration can be performed using the measurement result of the reference plate unit. Further, if the plate thickness is measured for the reference plate portion as well, the determination accuracy by the determination portion can be further improved.

According to the third aspect of the technique disclosed herein, if the jig is arranged so that the plate thickness direction is the horizontal direction, the fixed electrode is horizontal when both electrodes of the servo gun sandwich the jig. The coordinates of the direction become constant. On the other hand, if the jig is arranged so that the plate thickness direction is the vertical direction, the coordinates in the vertical direction of the fixed electrode become constant when both electrodes of the servo gun sandwich the jig. Therefore, the operation of the robot can be simplified. This makes it possible to further improve the work efficiency of the inspection.

Further, if the coordinates of the fixed electrodes are constant when both electrodes of the servo gun hold the jig, for example, when the coordinates of the servo gun are deviated due to the rattling of the robot, the jig is held. By confirming the position of the fixed electrode, the coordinate deviation can be confirmed. It is also possible to confirm whether or not the position of the work W or the like is displaced based on the position of the jig.

According to the fourth aspect of the technique disclosed herein, the jig is not easily deformed even if it is sandwiched between both electrodes of the servo gun a plurality of times. Therefore, the defect of the determination based on the deformation of the jig can be suppressed, and the determination accuracy by the determination unit can be further improved.

It is a figure which shows schematicly about the welding apparatus which concerns on this embodiment. It is a block diagram which shows the control system of a welding apparatus. It is an operation diagram which shows the operation of the servo gun at the time of measuring the plate thickness of a work, and shows the state which arranged the servo gun so that a jig is positioned between electrodes. It is a figure which shows the state which displaced a movable electrode from the state of FIG. 3 and brought it into contact with a jig. It is a figure which shows the state which sandwiched the jig between a fixed electrode and a movable electrode from the state of FIG. It is a front view of a jig. It is a side view of a jig. It is a figure which shows the state which sandwiched a jig between a fixed electrode and a movable electrode at the time of measuring the plate thickness of a jig.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. It should be noted that the following description of the preferred embodiment is essentially merely an example.

<overall structure>
FIG. 1 schematically shows a welding apparatus 1 according to an embodiment of the present invention. This welding device 1 is provided on a production line, and spot welds a work W (see FIG. 3 and the like) formed by stacking a plurality of plate-shaped members, and spots for joining the plate-shaped members to each other. It is a welding device.

As shown in FIG. 1, the welding device 1 has a robot 10 having a displaceable arm 11, a servo gun 20, and a control device 100 for operating and controlling the robot 10 and the servo gun 20. Further, as will be described in detail later, the welding apparatus 1 of the present embodiment has an inspection jig 30 fixed at a predetermined jig fixing position.

The robot 10 is an articulated industrial robot having three arms 11 rotatably connected to each other and a base 12. The three arms 11 include a base side arm 11a whose base end is connected to the base 12, a gun side arm 11b in which the servo gun 20 is held at the tip, and a tip portion and a gun side arm 11b of the base side arm 11a. It is composed of an intermediate arm 11c that connects to the base end side of the above. The base 12 is installed on the floor surface of the factory or the like, whereby the welding device 1 is fixed to the floor surface or the like of the factory.

The base side arm 11a is rotatably connected to the base 12 around an axis extending in the vertical direction. When the base side arm 11a rotates around the axis, each arm 11a to 11c rotates in the horizontal direction together with the servo gun 20.

The base 12 and the base end of the base side arm 11a, the tip of the base side arm 11a and one end in the longitudinal direction of the intermediate arm 11c, and the base end of the gun side arm 11b and the longitudinal length of the intermediate arm 11c. The other end in the direction is rotatably connected around a shaft 13 extending in the horizontal direction. The servo gun 20 can be moved back and forth in a direction orthogonal to both the vertical axis and the axis 13 by rotating each arm 11a to 11c around the axis 13.

Although not shown, the servo gun 20 is attached to the tip of the gun side arm 11b so as to be rotatable around an axis extending along the gun side arm 11b.

In the following description, the extending direction of the shaft 13 is referred to as a left-right direction, and the direction orthogonal to both the vertical direction and the axial direction of the shaft 13 is referred to as a front-back direction. Further, in the front-rear direction, the side where the servo gun 20 is away from the base 12 is called the front side, and the side where the servo gun 20 is close to the base 12 is called the rear side.

The servo gun 20 is provided at the U-shaped gun arm 21, the fixed electrode 22 provided at one of the two tips of the gun arm 21, and the other tip of the gun arm 21 so as to face the fixed electrode 22. A voltage application circuit 26 (see FIG. 2) that applies a voltage between the movable electrode 23 and the fixed electrode 22 and the movable electrode 23 that can be connected to and detached from the fixed electrode 22 by the servomotor 25 (see FIG. 2). And have. The movable electrode 23 is provided so as to project from the tip of the electrode case 23a. Further, the servo gun 20 is provided with a torque sensor 24 (see FIG. 2) that detects a load (torque) applied to the servomotor 25 when the work is sandwiched between the fixed electrode 22 and the movable electrode 23.

When joining the work W (see FIG. 4 and the like), the work W is sandwiched between the fixed electrode 22 and the movable electrode 23. After that, a current is passed between the electrodes 22 and 23 to join the plate-shaped members constituting the work W. The operation of the servo gun 20 when sandwiching the work W will be described later.

As shown in FIG. 2, the control device 100 includes a CPU 101, a memory 102, an interface 103, and a microprocessor having a path connecting these units.

The CPU 101 constitutes a gun control unit 101a that controls the operation of the servo gun 20. The CPU 101 constitutes a robot control unit 101b that controls the operation of the robot 10. When the inspected object is sandwiched between the fixed electrode 22 and the movable electrode 23, the CPU 101 calculates the thickness (plate thickness) of the inspected object from the amount of movement of the movable electrode 23 with respect to the fixed electrode 22, and the calculation result is obtained. However, it constitutes a detection unit 101c that detects an abnormality when the plate thickness is thinner than a predetermined amount or thicker than the predetermined amount with respect to the preset plate thickness. The CPU 101 constitutes a determination unit 101d for determining whether or not the plate thickness abnormality detection function of the detection unit 101c is functioning normally.

The gun control unit 101a of the CPU 101 controls the operation of the servomotor 25 and the voltage application circuit 26. The robot control unit 101b of the CPU 101 controls the operation of each arm 11 of the robot 10.

The memory 102 stores the position where the servo gun 20 should be set and the welding conditions (voltage to be applied between the electrodes, etc.) of the work W in the welding work of the work W.

In addition to the welding device 1, the control device 100 is connected to a display 104 showing an inspection result when the thickness (plate thickness) of the object to be inspected (work W and the inspection jig 30 described later) is inspected by the servo gun 20. There is.

<Plate thickness inspection>
The welding device 1 according to the present embodiment has a plate thickness inspection mechanism for inspecting the plate thickness of the work W or the like. There are various plate-shaped members constituting the work W, and the plate thickness may differ depending on the type of the work W. Further, the plate thickness of the work W as a whole may differ depending on how many plate-shaped members are stacked. Therefore, by inspecting the plate thickness of the work W to be welded to the desired plate thickness, it is possible to check whether a work W different from the desired work W is flowing to the production line, whether the plate-shaped member itself is defective, and the like. You can check.

The plate thickness inspection mechanism of the welding apparatus 1 according to the present embodiment measures the plate thickness of the inspected object from the amount of movement of the movable electrode 23 when the inspected object is sandwiched between the fixed electrode 22 and the movable electrode 23. , Inspect whether the plate thickness is desired. The operation of the servo gun 20 and the control of the control device 100 at this time will be described with reference to FIGS. 3 to 5.

First, as shown in FIG. 3, the robot control unit 101b of the CPU 101 operates the robot 10 so that the work W is located between the fixed electrode 22 and the movable electrode 23 of the servo gun 20 to move the servo gun 20. Let me. At this time, neither the fixed electrode 22 nor the movable electrode 23 is in contact with the work W.

Next, as shown in FIG. 4, the gun control unit 101a of the CPU 101 drives the servomotor 25 to move the movable electrode 23 until it comes into contact with the work W. Since the work W is usually positioned by a positioning device or the like, the position of the movable electrode 23 itself does not change after the work W comes into contact with the work W.

From the state of FIG. 4, when the servomotor 25 is driven by the gun control unit 101a of the CPU 101 to bring the movable electrode 23 closer to the fixed electrode 22, the reaction force causes the electrode case 23a to move as shown in FIG. The attached gun arm 21 moves. As a result, the work W is sandwiched between the fixed electrode 22 and the movable electrode 23. At this time, the position of the movable electrode 23 does not change, but the amount of protrusion of the movable electrode 23 from the electrode case 23a is large, so that the amount of movement of the gun arm 21 can also be regarded as the amount of movement of the movable electrode 23. Whether or not the work W is sandwiched between the fixed electrode 22 and the movable electrode 23 is determined by whether or not the torque detected by the torque sensor 24 reaches a predetermined torque. Specifically, when the torque detected by the torque sensor 24 reaches a predetermined torque, the CPU 101 determines that the work W is sandwiched between the fixed electrode 22 and the movable electrode 23.

Then, the detection unit 101c of the CPU 101 calculates the amount of movement of the movable electrode 23 with respect to the fixed electrode 22, and calculates the distance between the fixed electrode 22 and the movable electrode 23 when the work W is sandwiched, thereby calculating the work. Calculate the plate thickness of W. The amount of movement of the movable electrode 23 with respect to the fixed electrode 22 can be calculated, for example, by obtaining the number of rotations of the servomotor 25 before sandwiching the work W.

After calculating the plate thickness of the work W, the detection unit 101c of the CPU 101 detects an abnormality based on the calculated plate thickness. That is, when it is thinner than a predetermined amount or thicker than the predetermined amount with respect to the preset plate thickness, the detection unit 101c detects an abnormality. When an abnormality is detected by the detection unit 101c, for example, the welding operation is stopped and the display 104 displays that the abnormality has been detected. The setting plate thickness and the predetermined amount may differ for each work W, and can be arbitrarily set by the operator.

In this way, by providing the plate thickness inspection mechanism in the welding device 1, when plate-shaped members having an incorrect plate thickness are overlapped, or when the plate-shaped members themselves are defective and the plate thickness is thin or thick. For example, the worker can confirm it. This makes it possible to prevent defective products from being manufactured in advance.

However, since both electrodes 22 and 23 of the servo gun 20 are worn, the amount of movement of the movable electrode 23 cannot be accurately calculated due to the wear. Therefore, for example, even when the plate thickness of the work W is thicker than the set plate thickness by the predetermined amount or more, the detection unit 101c does not detect the abnormality, and the plate thickness inspection using the detection unit 101c is normally performed. I won't be able to. Further, even when the gun arm 21 is bent when the work W is sandwiched between the electrodes 22 and 23, the amount of movement of the movable electrode 23 cannot be calculated accurately, and the above-mentioned plate thickness inspection is normal. There is a risk that it will not be done.

It is possible to measure and correct the amount of wear of both electrodes 22 and 23, but if the correction value at this time is not accurate, the above-mentioned plate thickness inspection will not be performed normally.

Therefore, in the welding apparatus 1 according to the present embodiment, before the work W is put onto the production line, the plate thickness inspection using the detection unit 101c by the determination unit 101d of the CPU 101 using the inspection jig 30 is normal. It is trying to judge whether or not it is done in.

As shown in FIGS. 6 and 7, the inspection jig 30 is formed by processing a rectangular metal plate so that portions having different plate thicknesses are formed. The metal plate constituting the inspection jig 30 is set to a material and thickness so as not to be displaced or deformed even if it is sandwiched between the electrodes 22 and 23. In the present embodiment, the inspection jig 30 is a metal plate having a Rockwell hardness HRC of 60 or more. Specifically, for example, a JIS standard high-speed tool steel material (SKH) may be quenched so that the Rockwell hardness after quenching becomes HRC60 to 66. As the material of the inspection jig 30, a carbon tool steel material (SK) or a machine structural carbon steel material (SXXC) may be used.

As shown in FIG. 6, the inspection jig 30 has an inspection portion 31 formed in about half of one side in the short side direction, and is fixed to the jig fixing position in the other half of the short side direction. The fixing portion 32 is formed. The inspection unit 31 and the fixing unit 32 each extend in the long side direction without changing the width in the short side direction.

The inspection unit 31 includes a reference plate portion 33 having a plate thickness of a predetermined specific plate thickness, a first plate portion 34 having a plate thickness thinner than the predetermined amount with respect to the specific plate thickness, and the specific plate. It has a second plate portion 35 having a plate thickness that is thicker than the predetermined amount with respect to the thickness. The reference plate portion 33 is formed in the center in the long side direction, the first plate portion 34 is formed on one side in the long side direction with respect to the reference plate portion 33, and the second plate portion 35 is formed with respect to the reference plate portion 33. It is formed on the other side in the long side direction. As a result, as shown in FIG. 7, the inspection unit 31 has a shape in which the plate thickness gradually increases from the one side in the long side direction toward the other side. As shown in FIG. 7, the inspection unit 31 has a flat surface on one side (hereinafter referred to as a flat surface 31a) of the two surfaces in the plate thickness direction, while the other surface (hereinafter referred to as a stepped surface). By forming a step on (31b), the reference plate portion 33, the first plate portion 34, and the second plate portion 35 are formed, respectively.

The portion of the reference plate portion 33 on one side in the long side direction and on the other side in the short side direction is a curved portion 33a that is curved and inclined to the one side in the long side direction toward the other side in the short side direction. It has become. Further, in the second plate portion 35 as well as the reference plate portion 33, the portion on one side in the long side direction and the portion on the other side in the short side direction is in the long side direction toward the other side in the short side direction. The curved portion 35a is curved and inclined to one side of the above. The curved portions 33a and 35a do not necessarily have to be provided.

The fixing portion 32 is provided with two bolt holes 32a into which bolts are inserted. Although detailed illustration is omitted, the inspection jig 30 is fixed to the support portion provided at the jig fixing position in the work space of the welding device 1 by fastening and fixing the fixing portion 32 with a fastener such as a bolt. It is fixed at the jig fixing position. In the present embodiment, as shown in FIGS. 1 and 8, the inspection jig 30 is fixed to the jig fixing position so that the plate thickness direction is the front-rear direction (horizontal direction) and the long side direction is the vertical direction. ing.

Next, the operation of the welding device 1 when the determination unit 101d makes a determination using the inspection jig 30 will be described. When the determination unit 101d uses the inspection jig 30 to make a determination, the set plate thickness that serves as a detection reference for the detection unit 101c is preset to the specific plate thickness. Further, the determination by the determination unit 101d using the inspection jig 30 is automatically executed at least immediately after the production line is operated and before the work W is put on the production line. It has become.

First, at the time of non-operation immediately before the production line is operated, as shown in FIG. 1, the robot control unit 101b operates the robot 10 so that the servo gun 20 is positioned at a predetermined standby position. When the production line is operated from this state, the robot 10 operates so as to move the servo gun 20 from the standby position to the jig fixing position by the robot control unit 101b in order to measure the plate thickness of the inspection jig 30. Will be done. At this time, in the robot control unit 101b, as shown in FIG. 8, the fixed electrode 22 of the servo gun 20 is located on the flat surface 31a side of the inspection jig 30, while the movable electrode 23 of the servo gun 20 is the inspection jig 30. The robot 10 is operated so as to be located on the stepped surface 31b side of the above.

Next, the gun control unit 101a operates the servo gun 20 to inspect the plate thickness of the inspection jig 30. In the present embodiment, at least the plate thicknesses of the first plate portion 34 and the second plate portion 35 are inspected in the determination by the determination unit 101d. The gun control unit 101a operates the servo gun 20 in the same manner as when sandwiching the work W, and sequentially sandwiches the first plate portion 34 and the second plate portion 35 as shown in FIG. The detection unit 101c calculates the plate thickness of the first plate portion 34 and the second plate portion 35, respectively.

As described above, in the determination by the determination unit 101d, the set plate thickness is set to the specific plate thickness. Therefore, if the detection unit 101c functions normally, the detection unit 101c inspects the first plate portion 34, which is thinner than the specific plate thickness by the predetermined amount or more, and is thicker than the specific plate thickness by the predetermined amount or more. Abnormalities are detected by both inspections of the second plate portion 35. Therefore, when the determination unit 101d inspects the plate thickness of the first plate portion 34 and the second plate portion 35 and the detection unit 101c detects an abnormality in each inspection, the plate thickness inspection using the detection unit 101c is performed. Is determined to be normal. On the other hand, when the detection unit 101c does not detect an abnormality in at least one measurement, the determination unit 101d determines that the plate thickness inspection is defective. As a result, the determination by the determination unit 101d using the inspection jig 30 is completed.

When the determination unit 101d determines that the plate thickness inspection is defective, the CPU 101 informs the operator that the plate thickness inspection is defective by an alarm, a display on the display 104, or the like. After the defect is transmitted, the worker corrects whether the defect in the plate thickness inspection is caused by the wear of both electrodes 22 and 23, the abnormal bending of the gun arm 21, or the wear correction. If so, the cause such as whether the correction value of the wear correction is incorrect may be investigated, and an operation (calibration) for eliminating the defect of the plate thickness inspection may be performed. At this time, the operator can measure the plate thickness of the reference plate portion 33 by, for example, the robot 10 and the servo gun 20, and perform calibration from the measurement result.

Therefore, according to the present embodiment, the thickness of the object to be inspected is calculated from the amount of movement of the movable electrode 23 with respect to the fixed electrode 22, and the calculation result is whether the plate thickness is thinner than a predetermined amount with respect to the desired plate thickness. Alternatively, the detection unit 101c of the CPU 101 that detects an abnormality when the thickness is thicker than the predetermined amount, the determination unit 101d of the CPU 101 that determines whether or not the plate thickness inspection using the detection unit 101c is normally performed, and the space. The first plate portion 34, which is fixed at the jig fixing position and has a plate thickness thinner than the predetermined amount with respect to the preset specific plate thickness, and has a plate thickness thicker than the predetermined amount with respect to the specific plate thickness. A plate-shaped inspection jig 30 having a second plate portion 35 is provided, and the determination unit 101d has a desired plate thickness as the specific plate thickness, and the detection unit 101c is a plate of the first and second plate portions 34, 35. When the thickness is inspected and the detection unit 101c detects an abnormality in each inspection, it is determined that the plate thickness inspection is normally performed, while the detection unit 101c does not detect the abnormality in at least one inspection. Occasionally, it is determined that the plate thickness inspection is defective. As a result, it is possible to confirm whether or not the above-mentioned plate thickness inspection is normally performed only by inspecting the plate thickness of the inspection jig 30 fixed at the jig fixing position, so that the work efficiency is deteriorated. It can be suppressed. In particular, since it is not necessary to change the inspection standard for each dummy work as in the conventional case, improvement in work efficiency can be expected.

Further, both the first plate portion 34 having a plate thickness thinner than a predetermined amount with respect to the specific plate thickness and the second plate portion 35 having a plate thickness thicker than a predetermined amount with respect to the specific plate thickness are measured. In order to determine whether or not the plate thickness inspection is normally performed, the plate thickness inspection can be confirmed both when the plate thickness is thin and when the plate thickness is thick. Therefore, high determination accuracy can be obtained.

Further, unlike the conventional case, it is not necessary to facilitate a large number of dummy works, and one inspection jig 30 may be prepared, so that the work space can be suppressed and the cost can be reduced.

Further, in the present embodiment, the inspection jig 30 is fixed at the jig fixing position so that the plate thickness direction is the front-rear direction (horizontal direction) and the long side direction is the vertical direction, and the robot control of the CPU 101 is performed. The portion 101b moves the servo gun 20 from the standby position to the jig fixing position so that the fixed electrode 22 is located on the flat surface 31a side. As a result, when both electrodes 22 and 23 of the servo gun 20 sandwich the inspection jig 30, the horizontal coordinates of the fixed electrode 22 become constant. Therefore, the operation of the robot 10 can be simplified. Thereby, it is possible to more efficiently determine whether or not the plate thickness inspection is normally performed.

Further, if the horizontal coordinates of the fixed electrodes 22 when both electrodes 22 and 23 of the servo gun 20 sandwich the inspection jig 30 are constant, for example, the coordinates of the servo gun 20 will be changed due to the rattling of the robot 10. When the inspection jig 30 is misaligned, the coordinate deviation can be confirmed by confirming the position of the fixed electrode 22 when sandwiching the inspection jig 30. It is also possible to confirm whether or not the position of the work W or the like is displaced based on the position of the inspection jig 30.

Further, in the present embodiment, the inspection jig 30 has a Rockwell hardness HRC of 60 or more. Therefore, the inspection jig 30 is not easily deformed even if it is sandwiched between the electrodes 22 and 23 of the servo gun 20 a plurality of times. Therefore, the defect of the determination based on the deformation of the inspection jig 30 can be suppressed, and the accuracy of the determination as to whether or not the plate thickness inspection is normally performed can be further improved.

The technique disclosed herein is not limited to the above-described embodiment, and can be substituted as long as it does not deviate from the gist of the claims.

For example, in the above embodiment, when the determination unit 101d using the inspection jig 30 makes a determination, the first plate portion 34 and the second plate portion 35 are the inspection targets, but the present invention is not limited to this, and the reference plate portion is not limited to this. 33 may also be an inspection target. When inspecting the plate thickness of the reference plate unit 33, the determination unit 101d determines that the plate thickness inspection using the detection unit 101c is normally performed when the detection unit 101c does not detect an abnormality. When the detection unit 101c detects an abnormality, it is determined that a defect has occurred in the plate thickness inspection.

Further, in the above embodiment, the inspection jig 30 is fixed at the jig fixing position so that the plate thickness direction is the front-rear direction and the long side direction is the vertical direction, but the inspection jig 30 is not limited to this. The tool 30 may be arranged so that the plate thickness direction is the vertical direction and the long side direction is the front-rear direction.

Further, in the above embodiment, the determination by the determination unit 101d using the inspection jig 30 is executed immediately after the production line is operated, but in addition to this, the operator executes the determination at an arbitrary timing. You may be able to do it.

The above embodiments are merely examples, and the scope of the present disclosure should not be construed in a limited manner. The scope of the present disclosure is defined by the scope of claims, and all modifications and changes belonging to the equivalent scope of the scope of claims are within the scope of the present disclosure.

The technique disclosed herein is a welding apparatus having a servo gun having a fixed electrode and a movable electrode, and capable of inspecting the plate thickness of the inspected object by sandwiching the inspected object between the fixed electrode and the movable electrode. It is useful for confirming whether the thickness test is performed normally.

1 Welding device 10 Robot 20 Servo gun 22 Fixed electrode 23 Movable electrode 30 Inspection jig (inspected object, jig)
31a Flat surface (one side of the two surfaces in the thickness direction of the jig)
31b Stepped surface (the other side of the two surfaces in the plate thickness direction of the jig)
33 Reference plate 34 1st plate 35 2nd plate 101a Gun control 101b Robot control 101c Detection 101d Judgment unit

Claims (5)

A welding device provided with a servo gun having a fixed electrode and a movable electrode, and capable of inspecting the plate thickness of the inspected object by sandwiching the inspected object between the fixed electrode and the movable electrode.
The gun control unit that controls the operation of the above servo gun, and
When the thickness of the object to be inspected is calculated from the amount of movement of the movable electrode with respect to the fixed electrode, and the calculation result is that the plate thickness is thinner than a predetermined amount or thicker than the predetermined amount with respect to the desired plate thickness. A detector that detects abnormalities and
A determination unit that determines whether or not the plate thickness inspection of the inspected object using the detection unit is normally performed, and a determination unit.
A first plate portion that is fixed at a jig fixing position in the space and has a plate thickness that is thinner than the predetermined amount with respect to a preset specific plate thickness, and a plate thickness that is thicker than the predetermined amount with respect to the specific plate thickness. A plate-shaped jig having a second plate portion having a
The gun control unit is configured to operate the servo gun to measure the plate thickness of the first plate portion and the plate thickness of the second plate portion when making a determination by the determination unit. ,
When the detection unit inspects the plate thicknesses of the first and second plate portions with the desired plate thickness as the specific plate thickness, and the detection unit detects an abnormality in each inspection, the determination unit determines. A welding apparatus characterized in that while it is determined that the plate thickness inspection is normally performed, when the detection unit does not detect an abnormality in at least one of the inspections, it is determined that the plate thickness inspection is defective. In the welding apparatus according to claim 1,
The jig is a welding apparatus characterized by further having a reference plate portion whose plate thickness is set to the specific plate thickness. In the welding apparatus according to claim 1 or 2.
A robot that has multiple arms and is equipped with the above servo gun,
Further equipped with a robot control unit that controls the operation of the above robot,
In the jig, one of the two surfaces in the plate thickness direction is a flat surface, while a step is formed on the other surface to form at least the first and second plate portions. At the same time, it is fixed so that the plate thickness direction is the horizontal direction or the vertical direction.
The robot control unit operates the robot so that the servo gun is located at a predetermined standby position at least when the production line is not in operation, and when measuring the plate thicknesses of the first and second plate portions, the robot control unit is described. The robot is configured to operate the robot so as to move the servo gun from the standby position to the jig fixing position so that the fixed electrode is located on the one side in the plate thickness direction. Welding equipment. In the welding apparatus according to any one of claims 1 to 3.
The jig is a welding apparatus having a Rockwell hardness HRC of 60 or more. In a welding device provided with a servo gun having a fixed electrode and a movable electrode, a plate thickness inspection method for the welding device, in which the plate thickness of the inspected object is inspected by sandwiching the inspected object between the fixed electrode and the movable electrode. And
The welding device has a first plate portion that is fixed at a jig fixing position in a space and has a plate thickness that is thinner than a predetermined amount with respect to a preset specific plate thickness, and the predetermined amount or more with respect to the specific plate thickness. Further provided with a plate-shaped jig having a second plate portion having a thick plate thickness,
As a step of determining whether or not the plate thickness inspection by the above welding device is normally performed,
The first measurement step of sandwiching the first plate portion between the fixed electrode and the movable electrode and measuring the plate thickness of the first plate portion.
Based on the measurement results of the first measurement step, the first detection step of detecting an abnormality in the plate thickness and
A second measurement step of sandwiching the second plate portion between the fixed electrode and the movable electrode and measuring the plate thickness of the second plate portion.
Based on the measurement results of the second measurement step, the second detection step of detecting an abnormality in the plate thickness and
Including
The first and second detection steps are steps for detecting an abnormality when the plate thickness is thinner than a predetermined amount or thicker than the predetermined amount with respect to the specific plate thickness.
In the determination step, when an abnormality is detected in both the first and second detection steps, it is determined that the plate thickness inspection is normally performed, while the first and second detection steps are performed. A method for inspecting a plate thickness of a welding apparatus, which is a step of determining that there is a defect in the above-mentioned plate thickness inspection when no abnormality is detected in at least one of the detection steps.

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