JP7002689B1 - How to insert a robot-type friction stir welding device and its joining tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a robot type friction stir welding device provided with a friction stir welding unit at the tip of an articulated robot arm when the surface of the member to be welded is not flat due to uneven plate thickness or the like or the influence of reaction force from the member to be welded. A highly reliable robot that can insert the joining tool into the proper vertical downward direction (Z-axis downward direction) even when the size is large, and can suppress blurring when the joining tool rotates at high speed. A type friction stir welding apparatus is provided. SOLUTION: The articulated robot arm is provided with a friction stirring joining unit attached to the tip of the articulated robot arm, and the friction stirring joining unit is via a Z-axis vertical power drive motor and a spindle support portion. It has a main shaft attached to the Z-axis vertical movement drive motor and a rotation power generating means for generating rotation power, and the rotation center portion of the rotation power generating means is the center of gravity axis of the tip of the articulated robot arm. It is characterized by applying rotational power to the joining tool in the spindle arranged above. [Selection diagram] FIG. 1A

Description

The present invention is related to the configuration and control of a friction stir welding device that joins members to be joined by friction stir welding, and is particularly applied to joining members to be joined that require high quality (high accuracy) joining. Regarding effective technology.

Friction stir welding (FSW) is a method other than materials, in which the material to be welded is softened by the frictional heat generated by rotating a columnar joining tool and the parts to be welded are agitated to join the materials to be welded together. Since no material is used, the fatigue strength is high and the material does not melt, so welding with less welding deformation (strain) is possible, and it is expected to be applied in a wide range of fields such as aircraft and automobile bodies.

As a background technology in this technical field, for example, there is a technology such as Patent Document 1. In Patent Document 1, "marking is applied to the outer peripheral surface of the main body of the joining tool, and the current marking position (current marking position) is detected by using a measuring device while inserting the joining tool into the member to be joined, and the current marking position is the target. A control method for ending the insertion process when the marking position is reached ”is disclosed.

According to this control method, it is possible to eliminate the influence of foreign matter such as burrs adhering to the tip of the joining tool and insert the joining tool into the member to be joined up to the proper insertion position.

Further, in Patent Document 2, "while rotating the rotation tool, a pressing force is applied to the rotation tool by the arm of the articulated robot to insert it into the member to be joined, and the rotation tool is set at a desired position in the downward direction of the Z axis. "Friction stir welding device" is disclosed.

Japanese Unexamined Patent Publication No. 2019-2006026 JP-A-2019-171620

In the method of inserting the joining tool disclosed in Patent Document 1 into the member to be joined, the plate thickness of the member to be joined is uniform, the surface of the member to be joined is flat and has no waviness, and the Z-axis of the surface is not formed. It is effective when the position in the direction is constant.

However, the inventors of the present application have found that this control method is not always effective when the member to be joined has undulations or the like, and the joining tool may not be properly inserted into the member to be joined.

Further, the method of inserting the joining tool disclosed in Patent Document 2 into the member to be joined is not a problem when the member to be joined is a thin metal plate or soft (small deformation resistance), but when the member is a thick metal plate or the like. May be affected by the reaction force from the member to be joined, and the joint portion of the articulated robot may become unstable. As a result, it is expected that the joining tool cannot be inserted into the proper position of the member to be joined. In addition, it is expected that blurring will occur when the joining tool is rotated at high speed, which will affect the joining quality.

Therefore, an object of the present invention is to use a robot-type friction stir welding device provided with a friction stir welding unit at the tip of an articulated robot arm when the surface of the member to be welded is not flat due to uneven plate thickness or waviness, or to be welded. Even when the influence of the reaction force from the member is large, the joining tool can be inserted into the proper vertical downward direction (Z-axis downward direction) before starting friction stir welding, and the joining is performed. It is an object of the present invention to provide a highly reliable robot-type friction stir welding apparatus capable of suppressing blurring when the tool rotates at high speed, and a method for inserting the joining tool.

In order to solve the above problems, the present invention includes an articulated robot arm and a friction stirring joining unit attached to the tip of the articulated robot arm, and the friction stirring joining unit is driven by Z-axis vertical movement. It has a motor, a spindle attached to the Z-axis vertical movement drive motor via a spindle support portion, and a rotational power generation means for generating rotational power. The rotational center portion of the rotational power generation means is the said. The center of gravity of the mounting surface of the friction stirring joining unit at the most advanced portion of the final stage arm of the articulated robot arm in the direction perpendicular to the vertical direction of the mounting surface of the friction stirring joining unit at the most advanced portion of the final stage arm of the articulated robot arm. It is characterized in that a rotational force is applied to a joining tool in the spindle arranged on the shaft.

Further, the present invention is a method of inserting a joining tool into a member to be joined by the above-mentioned robot type friction stirring joining device, and (a) an articulated robot arm in a stage before starting friction stirring joining of the member to be joined. A step of teaching the friction stirring joining unit to the joining position of the member to be joined by driving each joint portion of the above, and (b) after the step (a), the target load factor of the spindle motor and the Z-axis vertical movement drive. After the target value setting step for setting the target drive amount of the motor and (c) the step (b), the Z-axis vertical drive motor is driven to move the spindle downward to the Z-axis, and the spindle is moved downward. It has a step of executing an insertion process of inserting the joining tool into the member to be joined while rotating the joining tool at a predetermined rotation speed by a motor, and in the step (c), (c1) in a predetermined sampling cycle. , The state amount acquisition step for acquiring the current load factor indicating the current value of the load factor of the spindle motor and the current drive amount indicating the current value of the drive amount of the Z-axis vertical movement drive motor, and (c2) the present. It is characterized by further having a comparison step of comparing the load factor with the target load factor, and then comparing the current drive amount with the target drive amount.

According to the present invention, in a robot-type friction stir welding device provided with a friction stir welding unit at the tip of an articulated robot arm, when the surface of the member to be welded is not flat due to uneven plate thickness, waviness, etc., or from the member to be welded. Even when the influence of the reaction force is large, the joining tool can be inserted in the proper vertical downward direction (Z-axis downward direction) before starting friction stir welding, and the joining tool can be used. It is possible to realize a highly reliable robot-type friction stir welding device and a method for inserting a joining tool that can suppress blurring during high-speed rotation.

This enables high-quality (high-precision) friction stir welding between the members to be joined.

Issues, configurations and effects other than those described above will be clarified by the description of the following embodiments.

It is a figure which shows the whole outline of the robot type friction stir welding apparatus which concerns on Example 1 of this invention. It is an enlarged view of the friction stir welding unit 18 of FIG. 1A. It is a figure which shows the modification of FIG. 1B. It is a figure which conceptually shows the relationship between a spindle motor load factor and a tool insertion operation. It is a figure which shows the state at the time of setting the zero point of a joining tool. It is a figure which shows the relationship of each parameter at the time of satisfying the first insertion process end condition. It is a figure which shows the relationship of each parameter at the time of satisfying the 2nd insertion process end condition. It is a flowchart which shows the insertion method of the joining tool which concerns on Example 1 of this invention. It is a figure which shows the relationship of each parameter at the time of damage detection of the joining tool which concerns on Example 2 of this invention. It is a figure which shows the state at the time of inserting the joining tool of the conventional friction stir welding apparatus. It is a figure which shows the state at the time of inserting the joining tool of the conventional friction stir welding apparatus.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In each drawing, the same components are designated by the same reference numerals, and the detailed description of the overlapping portions will be omitted.

Further, the "push-in amount" described below is the amount of descent of the joining tool that determines how deep the joining tool is inserted from the surface of the member to be joined, that is, the rotation of the joining tool and the Z-axis vertical drive motor. It means the amount of movement perpendicular to the axis.

First, with reference to FIGS. 8 and 9, the above-mentioned problems to be solved by the present invention will be described in detail. 8 and 9 are views showing a state when a conventional general friction stir welding device is inserted with a joining tool, and each of the case where the member to be welded has no swell (FIG. 8) and the member to be welded have swell. (Fig. 9) is shown.

When the control method of Patent Document 1 is used, as shown in FIG. 8, when the member to be joined does not have undulations or the like, even if foreign matter 17 adheres to the tip of the joining tool, the joining tool is accurately inserted at the proper insertion position. It is possible to insert up to.

However, as shown in FIG. 9, when the member to be joined has a swell or the like, a convex portion exists on the surface of the member to be joined, and the convex amount (ΔI portion) is inserted beyond the proper insertion position. It cannot be inserted accurately. The position of the joining tool at the end of the insertion process matches the target insertion amount, but there is a positional deviation of ΔI from the appropriate insertion amount.

Therefore, although not shown, when the thickness of the member to be joined is thin and the deviation between the Z-axis position on the surface and the Z-axis position of the mounting table of the friction stir welding device is small, the tip of the joining tool penetrates the member to be joined. There is also a risk that it will end up.

Next, with reference to FIGS. 1A and 2, the configuration of the robot-type friction stir welding apparatus which is the object of the present invention and its control will be described. FIG. 1A is a diagram showing an overall outline of a robot-type friction stir welding apparatus according to this embodiment. FIG. 1B is an enlarged view of the friction stir welding unit 18 of FIG. 1A. FIG. 1C is a diagram showing a modified example of FIG. 1B. FIG. 2 is a diagram conceptually showing the relationship between the spindle motor load factor and the tool insertion operation.

As shown in FIG. 1A, the robot-type friction stir welding device 1 of the present embodiment includes an articulated robot arm 2 and a friction stir welding unit 18 attached to the tip of the articulated robot arm 2 as a main configuration. ing.

The articulated robot arm 2 is a vertical articulated robot generally called a "robot arm", and can freely move (move) in a three-dimensional space by an articulated structure and a servo motor. The range of motion changes depending on the number of joints (number of axes), but here, a multi-axis type multi-joint having legs 2b, lower arm 2c, upper arm 2d, wrists 2e, 2f, 2g on the pedestal 2a. An example of a robot arm is shown.

A friction stir welding unit 18 is connected to the tip of the wrist portion 2g of the articulated robot arm 2.

As shown in FIG. 1B, the friction stirring joining unit 18 includes a Z-axis vertical movement drive mechanism unit 3 having a Z-axis vertical movement drive motor 16 and a Z-axis vertical movement drive motor 16 (Z-axis) via a spindle support portion 4. The spindle 15 attached to the vertical movement drive mechanism 3), the tool holder (joining head) 5 arranged inside the spindle 15, the joining tool 6 supported by the tool holder (joining head) 5, and the joining tool. It is configured to include a spindle motor 14 that is directly (FIG. 1C) or indirectly (FIG. 1B) connected to 6 to rotate the joining tool 6 at a predetermined rotation speed.

Then, in the friction stir welding unit 18 of the present embodiment, as shown in FIGS. 1B and 1C, the rotation center portion of the joining tool 6 is attached to the arm tip portion of the articulated robot arm 2 to which the friction stir welding unit 18 is attached. By arranging it on the axis of the center of gravity, it is possible to suppress blurring that occurs when the joining tool 6 rotates at high speed.

The rotational power generating means for applying rotational power to the joining tool 6 has either the configuration shown in FIG. 1B or the configuration shown in FIG. 1C, and rotates at a predetermined rotation speed to the joining tool 6 as shown below. Gives rotation power.

In the configuration of FIG. 1B, the spindle motor 14 is arranged outside the spindle 15. In this configuration, the main shaft 15 includes a joining tool 6, and a main shaft motor 14 as a turning power generating means is arranged outside the main shaft 15.

Then, the spindle motor 14 is rotated at a predetermined rotational speed to generate rotational power, and the drive side rotating body (pulley or the like) 20 attached to the rotating shaft of the spindle motor 14 and the driven side attached to the joining tool 6 are used. The rotating power of the spindle motor 14 via a rotating power transmission mechanism including a rotating body (pulley or the like) 19 and a joining means (belt or the like) 21 for connecting the driving side rotating body 20 and the driven side rotating body 19. Is indirectly transmitted to the joining tool 6.

Further, in the configuration of FIG. 1C, the spindle motor 14 is arranged in the spindle 15. In this configuration, the joining tool 6 is directly connected to the rotating shaft of the spindle motor 14, and when the spindle motor 14 rotates at a predetermined rotational speed to generate rotational power, the rotational power is directly transmitted to the joining tool 6. Is.

In both cases of FIGS. 1B and 1C, it is important to arrange the rotation center portion of the joining tool 6 on the axis of the center of gravity of the arm tip portion of the articulated robot arm 2. As a result, it is possible to suppress blurring when the joining tool 6 is rotated at high speed.

With the above configuration, the robot-type friction stir welding device 1 is less susceptible to the reaction force from the member 9 to be joined when the joining tool 6 is inserted into the member 9, and the joining tool 6 is attached to the member to be joined. It is possible to suppress blurring even when rotating at high speed in 9.

Which of FIG. 1B and FIG. 1C should be selected may be determined by factors such as the space of the installation location. The advantage of the configuration of FIG. 1B is that by arranging the spindle motor 14 outside the spindle 15, the spindle 15 and the spindle motor 14 are arranged in parallel instead of in series. Therefore, from the arm tip portion of the articulated robot arm 2. The space in the downward direction of the Z axis to the tip of the joining tool can be reduced.

On the other hand, when the configuration shown in FIG. 1C is selected, the spindle 15 and the spindle motor 14 are arranged in series. Therefore, compared with the configuration shown in FIG. It is necessary to secure a large space in the downward direction of the Z axis up to the portion, but since the spindle motor 14 and the joining tool 6 are directly connected, the effect of suppressing blurring can be further expected.

As illustrated in FIGS. 1A to 1C, a ball screw, a linear guide, or the like is used for the Z-axis vertical movement drive mechanism unit 3, and the wrist of the articulated robot arm 2 is provided by the Z-axis vertical movement drive motor 16. The spindle 15 can be driven in the Z-axis direction (vertical direction) with respect to the portion 2g (spindle support portion 4).

The joining tool 6 is composed of a shoulder portion 7 and a probe portion (joining pin) 8 and is connected to the spindle motor 14 (directly connected in FIG. 1C). The spindle motor 14 rotates the joining tool 6 in a predetermined direction.

The articulated robot arm 2 supports the spindle support portion 4 and the spindle 15 via the Z-axis vertical movement drive mechanism unit 3, and the control unit (control device) 11 mounted (attached) on the articulated robot arm 2 Z. A drive signal is applied to the shaft vertical drive motor 16 and the spindle motor 14, the spindle 15 is driven in the Z-axis direction (vertical direction), and the joining tool 6 is rotated to advance along the joining line. That is, the articulated robot arm 2 holds the spindle support portion 4, the spindle 15, and the tool holder (joining head) 5, rotates the joining tool 6, and moves the joining tool 6 in the X-axis direction of FIG. 1A. Let me.

While rotating the joining tool 6 at a predetermined rotation speed, frictional heat is generated by pressing the shoulder portion 7 and the probe portion 8 onto the joining line on the surface of the member 9 (9a, 9b) to be joined mounted on the mounting table 10. To soften the member 9 to be joined, insert a required amount of the shoulder portion 7 and the probe portion 8 into the member 9 to be joined, and maintain the rotation speed to generate plastic flow and stir the inserted portion. .. By pulling out or moving the joining tool 6, the stirring portion (joining portion) is cooled, and the member to be joined 9 is joined.

The shoulder portion 7 and the probe portion (bonding pin) 8 may be the same joining tool (that is, the shoulder portion 7 does not have a probe and only the shoulder portion), or the shoulder portion 7 may not rotate. good.

Further, FIG. 1A shows an example in which the articulated robot arm 2 and the mounting table 10 are installed on the same frame 12 and the legs 13 of the table, but the articulated robot arm 2 and the mounting table 10 are separately installed. You may install it.

The robot-type friction stir welding device 1 includes a control unit (control device) 11 in which a motor controller, a CPU unit, and the like are housed, and is an articulated robot according to a command (program signal) from the control unit (control device) 11. The movement of the arm 2 and the joining conditions of the friction stir welding unit are comprehensively controlled.

The control unit (control device) 11 holds a joint condition signal for determining the joining condition by the joining tool 6 and a holding position (insertion of the joining pin 8) in the vertical direction (Z direction) of the joining tool 6 by the Z-axis vertical movement drive mechanism unit 3. It is provided with a storage unit (not shown) for storing junction parameters (FSW junction conditions) such as a holding position determination signal that determines the amount).

The control unit 11 may be built in, for example, the pedestal portion 2a of the articulated robot arm 2, or may be configured separately from the articulated robot arm 2 as a control device as shown in FIG. 1A. Further, the control unit of the friction stir welding unit may be shared with the control unit of the articulated robot arm 2, or may be configured separately.

Here, the relationship between the spindle motor load factor and the tool insertion operation will be described with reference to FIG. As shown in FIG. 2, the joining tool position is related to the load factor of the spindle motor 14.

When the probe portion (joining pin) 8 is brought into contact with the member to be joined 9 and the insertion of the joining tool 6 is started, the load factor of the spindle motor 14 increases as the position of the joining tool becomes deeper.

If the shoulder portion 7 comes into contact with the member 9 to be joined while the joining tool 6 is being inserted, the rate of increase in the load factor of the spindle motor 14 temporarily decreases, but when the joining tool 6 is further inserted, the spindle motor 14 The rate of increase in load factor increases again.

When the target load factor at the time of inserting the joining tool 6 or the target joining tool position is reached, the insertion process of the joining tool 6 is completed, and the joining tool 6 is rotated for a certain period of time with the joining tool position fixed. Heat treatment is performed on the member 9 to be joined.

After that, the friction stir welding process of the member 9 to be welded is performed. During the friction stir welding process, the drive of the spindle motor 14 and the Z-axis vertical drive motor 16 is controlled so that both the spindle motor load factor and the joining tool position are maintained at constant values (target values).

When the drawing of the joining tool 6 is started at the time when the friction stir welding process is completed, the load factor of the spindle motor 14 decreases as the position of the joining tool becomes shallower.

As described above, in the robot type friction stir welding apparatus 1 of the present embodiment, when the friction stir welding of the members to be joined 9 is performed, the material, thickness and the like of the members to be welded 9 are joined in order to ensure high quality bonding. Based on the conditions, in the insertion process, the joining tool 6 is inserted into the member to be joined 9 to the proper insertion position while rotating the joining tool 6 at a predetermined rotation speed. After that, the joining tool 6 is rotated at the insertion position until the joint portion of the member to be joined 9 reaches the target heat input amount, and the heat treatment is performed. When the joint portion reaches the target heat input amount, the joint tool 6 is advanced along the joint line to execute the joint process.

The “damage detection load factor” in FIG. 2 will be described later in Example 2.

Next, the insertion process of the joining tool 6 of the robot-type friction stir welding device 1 according to the present embodiment will be described with reference to FIGS. 3 to 6. FIG. 3 is a diagram showing a state of the joining tool 6 when the zero point is set. FIG. 4 is a diagram showing the relationship of each parameter when the first insertion processing end condition is satisfied, and FIG. 5 is a diagram showing the relationship of each parameter when the second insertion process end condition is satisfied. FIG. 6 is a flowchart showing a method of inserting the joining tool 6 in this embodiment.

In the robot-type friction stir welding device 1 to which the present invention is applied, the joining tool 6 is inserted into the joined member as follows so that the joining tool position when the joining tool 6 is inserted into the joined member 9 is the proper insertion position. The insertion process to be inserted into 9 is executed.

First, the robot-type friction stir welding device 1 drives each joint portion so that the joining tool 6 is at a predetermined joining position of the member 9 to be joined, and aligns the friction stir welding unit attached to the tip of the arm. Execute teaching, which is a process.

Next, as shown in FIG. 3, at that position, the robot-type friction stir welding device 1 drives the main shaft 15 by driving the Z-axis vertical movement drive motor 16 in the stage before starting the joining process by the joining tool 6. It is driven downward, that is, the joining tool 6 is driven downward to align the tip end portion with the surface of the member 9 to be joined, and the zero point of the joining tool position indicating the position of the joining tool 6 is set. The zero point is a reference position for the joining tool position at the Z-axis position indicating the position in the downward direction of the Z-axis, which is the vertical downward direction.

Subsequently, in the pre-stage, the insertion process is executed on a trial basis as follows. The robot-type friction stirring joining device 1 has a spindle according to a target rotation speed (target rotation speed) of the spindle motor 14 set based on joining conditions depending on the member 9 to be joined, such as the material and thickness of the member 9 to be joined. While rotating the motor 14, the Z-axis vertical movement drive motor 16 is driven to increase the amount of drive, and the Z-axis position can secure the desired joining quality without requiring the activation of the articulated robot arm 2. The spindle 15 is driven downward to insert the joining tool 6 attached to the spindle 15 into an appropriate insertion position of the member 9 to be joined. The driving amount of the Z-axis vertical movement drive motor 16 at this time is set as the target driving amount.

Further, in the previous stage, the robot type friction stirring joining device 1 sets the target rotation speed of the spindle motor 14 and the target drive amount of the Z-axis vertical movement drive motor 16 and executes the insertion process again on a trial basis. The joining tool 6 is inserted into the member 9 to be joined up to the position of the joining tool where highly accurate joining quality can be obtained, and the load factor of the spindle motor 14 at this time (calculated with the maximum value of the load torque of the spindle motor 14 as 100). (Value to be calculated), or the load factor of the Z-axis vertical movement drive motor 16 (value calculated with the maximum value of the load torque of the Z-axis vertical movement drive motor 16 as 100), or the spindle support portion 4 or the Z-axis vertical movement drive. The actual load applied to the mechanism unit 3 is acquired, and these values are set as the target load factor.

The load factor of the spindle motor 14 and the load factor of the Z-axis vertical drive motor 16 can be obtained by the current value applied to each motor, but when the actual load of the spindle support portion 4 is used, the actual load (load value). Etc.) will be used.

The robot-type friction stir welding device 1 executes an actual insertion process after all the test insertion processes are completed.

The robot-type friction stir welding device 1 first sets a target rotation speed, a target drive amount, and a target load factor.

Next, the robot-type friction stir welding device 1 drives each joint portion so that the joining tool 6 is at a predetermined joining position of the member 9 to be joined, and teaches the friction stir welding unit attached to the tip of the arm. To execute.

At that position, the robot-type friction stirring joining device 1 drives the Z-axis vertical movement drive motor 16 while rotating the spindle motor 14 at the target rotation speed of the spindle motor 14, increases the amount of driving, and causes the spindle 15 to move. It descends to start inserting the joining tool 6 attached to the tip of the spindle 15 into the member to be joined 9.

After the teaching is completed, each joint portion of the articulated robot arm 2 is fixed without operating until the insertion process is completed, and the articulated robot arm 2 holds the position.

Further, the Z-axis vertical movement drive motor 16 moves down the friction stir welding unit, that is, the joining tool 6 while increasing the driving amount toward the target driving amount, and in the process, it is set on time, that is, in advance. In the set sampling cycle, the current load factor indicating the actual physical quantity corresponding to the target load factor is acquired.

Next, in the same sampling in which the current load factor is acquired, the current load factor and the target load factor are compared as the first insertion processing end condition, and whether the first deviation, which is the deviation, has reached the allowable range. Check if not. If the first deviation reaches within the permissible range, it is assumed that the first insertion processing end condition is satisfied, and the insertion process is terminated at this point.

When the first insertion processing end condition is not satisfied, in the same sampling described above, as the second insertion processing end condition, the current charging amount and the target charging amount are compared, and the second deviation, which is the deviation, is obtained. Check if the tolerance is reached. If the second deviation reaches within the permissible range, it is assumed that the second insertion processing end condition is satisfied, and the insertion process is terminated at this point.

When the second insertion processing end condition is not satisfied, the driving amount of the Z-axis vertical movement drive motor 16 is further increased, and whether the first insertion processing end condition is satisfied or the second insertion processing end condition is satisfied. Repeat the check to see if is true.

In this way, the robot-type friction stir welding device 1 increases the amount of drive of the Z-axis vertical drive motor 16 and inserts the joining tool 6 into the member to be joined 9 while performing the first insertion processing end condition and the second. The status of establishment of the insertion processing end condition is checked, and the insertion processing is terminated when either the first insertion processing end condition or the second insertion processing end condition is satisfied.

As can be seen from these facts, the target drive amount, which is a requirement for establishing the second insertion process end condition, is set as the maximum drive amount of the Z-axis vertical movement drive motor 16. That is, it becomes a limiter of the insertion position of the joining tool 6.

After the insertion process is completed as described above, the process proceeds to the friction stir welding process with the bonding tool position as the initial value.

The permissible ranges for the first insertion processing end condition and the second insertion processing end condition may be set based on the measured values when the insertion processing is executed on a trial basis, or from the joining conditions. It may be set by the calculated value.

Further, the current load factor when the load factor of the spindle motor 14 is set as the target load factor uses the current value of the load factor of the spindle motor 14, and the load factor of the Z-axis vertical drive motor 16 is set as the target load factor. The current load factor at this time uses the current value of the load factor of the Z-axis vertical drive motor 16, and the current load factor when the actual load of the spindle support unit 4 is set as the target load factor is the actual load factor of the spindle support unit 4. The current value will be used.

Further, whether to select the load factor of the spindle motor 14, the load factor of the Z-axis vertical drive motor 16, or the actual load of the spindle support portion 4 as the target load factor is controlled in advance by the joining condition of the member 9 to be joined. It may be set in the unit 11, or a selection menu may be displayed in the control unit 11 so that the robot type friction stir welding device 1 can be selected from the menu at the start of operation.

The method of inserting the above-mentioned joining tool 6 will be described with reference to FIG.

First, in step S1, in the stage before starting friction stir welding, the friction stir welding unit is taught at the joint position of the member to be welded 9 by driving each joint portion of the articulated robot arm 2.

Next, in step S2, the control unit 11 sets a target value for the insertion process of the joining tool 6. Here, the target load factor of the spindle motor 14 is L0, and the target drive amount of the Z-axis vertical movement drive motor 16 is D0.

Subsequently, in step S3, the current value of the load factor of the spindle motor 14 and the current value of the drive amount of the Z-axis vertical movement drive motor 16 are acquired in a predetermined sampling cycle. Here, the current load factor is Lt, and the current drive amount is Dt.

Next, in step S4, the deviation (| Lt --L0 |) between the current load factor: Lt and the target load factor: L0 is compared with the allowable range.

When it is determined that | Lt --L0 | is within the allowable range, the insertion process of the joining tool 6 is terminated. On the other hand, if it is determined that | Lt --L0 | is out of the permissible range, the process proceeds to step S5.

Subsequently, in step S5, the deviation (| Dt --D0 |) between the current drive amount: Dt and the target drive amount: D0 is compared with the allowable range.

If it is determined that | Dt --D0 | is within the permissible range, the insertion process of the joining tool 6 is terminated. On the other hand, if it is determined that | Dt --D0 | is out of the permissible range, the process returns to step S3 and the processes of steps S3 to S5 are repeated.

As described above, according to the robot-type friction stir welding apparatus of this embodiment and the method of inserting the joining tool, when the surface of the member to be welded is not flat due to uneven plate thickness, waviness, etc., or from the member to be welded. Reliable robotic friction that allows the joining tool to be inserted into the proper vertical downward (Z-axis downward) position before starting friction stir welding, even if the reaction force of the It is possible to realize a method of inserting a stirring joining device and a joining tool. This enables high-quality (high-precision) friction stir welding between the members to be joined.

In the robot-type friction stir welding device 1 of the present embodiment, the friction stir welding unit 18 can be freely moved in a three-dimensional space by the articulated robot arm 2. Therefore, in addition to general line bonding, it is covered. It can also be applied to point joining in which joining members are joined intermittently.

A robot-type friction stir welding apparatus and a method for inserting the joining tool according to the second embodiment of the present invention will be described with reference to FIG. 7. FIG. 7 is a diagram showing the relationship between each parameter at the time of damage detection of the joining tool in the robot type friction stir welding device of this embodiment.

As shown in FIG. 7, in the robot type friction stir welding apparatus 1 of the present embodiment, when the insertion process is executed on a trial basis in the stage before the joining process is started by the joining tool 6, the target load factor and the target drive amount In addition to setting, the damage detection load factor and the damage detection drive amount for detecting the damage of the joining tool 6 on a trial basis are set.

In the actual operation stage, the robot-type friction stir welding apparatus 1 has a current load factor and a Z-axis vertical drive that indicate an actual physical quantity corresponding to the target load factor in a preset sampling cycle after the insertion process is started. The current drive amount indicating the current value of the drive amount of the motor 16 is acquired.

In the sampling to check the establishment status of the first insertion process end condition and the second insertion process end condition, the third deviation is calculated as the deviation between the current charge amount and the damage detection charge amount as the joining tool damage condition. Furthermore, the fourth deviation is calculated as the deviation between the current load factor and the damage detection load factor.

When the third deviation has reached the permissible range and the fourth deviation has not reached the permissible range, the robot type friction stir welding device 1 performs the insertion process on the assumption that the joining tool damage condition is satisfied. finish.

The damage detection load factor when the load factor of the spindle motor 14 is set as the target load factor is set by the load factor of the spindle motor 14, and the current value of the load factor of the spindle motor 14 is used as the current load factor.

The damage detection load factor when the load factor of the Z-axis vertical drive motor 16 is set as the target load factor is set by the load factor of the Z-axis vertical drive motor 16, and the current load factor is the Z-axis vertical drive motor 16 Use the current value of the load factor of.

The damage detection load factor when the actual load of the spindle support portion 4 is set as the target load factor is set by the actual load of the spindle support portion 4, and the current value of the actual load of the spindle support portion 4 is used as the current load factor.

According to this embodiment, the joining tool 6 (probe portion 8) is monitored by monitoring the load factor of any of the spindle motor 14, the Z-axis vertical drive motor 16, and the spindle support portion 4 and the driving amount of the joining tool 6. It is possible to detect the presence or absence of damage. As a result, when damage such as wear or breakage occurs in the joining tool 6 (probe portion 8), it is possible to prevent the friction stir welding by the damaged joining tool 6 from continuing.

The present invention is not limited to the above-described embodiment, and includes various modifications. For example, the above-described embodiment has been described in detail in order to explain the present invention in an easy-to-understand manner, and is not necessarily limited to the one including all the described configurations. Further, it is possible to replace a part of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment. Further, it is possible to add / delete / replace a part of the configuration of each embodiment with another configuration.

1 ... Robot type friction stirring joining device, 2 ... Articulated robot arm, 2a ... Pedestal part, 2b ... Leg part, 2c ... Lower arm part, 2d ... Upper arm part, 2e, 2f, 2g ... Wrist part, 3 ... Z axis Vertical movement drive mechanism, 4 ... spindle support, 5 ... tool holder (joining head), 6 ... joining tool, 7 ... shoulder part, 8 ... probe part (joining pin), 9, 9a, 9b ... joined member, 10 ... mounting base, 11 ... control unit (control device), 12 ... pedestal, 13 ... pedestal leg, 14 ... spindle motor, 15 ... spindle, 16 ... Z-axis vertical drive motor, 17 ... foreign matter, 18 ... friction Stirring joining unit, 19 ... driven side rotating body (pulley), 20 ... driving side rotating body (pulley), 21 ... joining means (belt).

Claims (12)

With an articulated robot arm,
A friction stir welding unit attached to the tip of the articulated robot arm is provided.
The friction stir welding unit includes a Z-axis vertical drive motor and
The spindle attached to the Z-axis vertical drive motor via the spindle support,
It has a turning power generating means and, which generates turning power.
In the rotational power generating means, the center of rotation is the tip of the final arm of the articulated robot arm in the direction vertically downward of the mounting surface of the friction stir welding unit at the tip of the final arm of the articulated robot arm. A robot-type friction stir welding device characterized in that a rotational force is applied to a bonding tool in the spindle arranged on the axis of the center of gravity of the mounting surface of the friction stir welding unit of the unit. The robot-type friction stir welding device according to claim 1.
A spindle motor is arranged outside the spindle,
It is composed of a driving side rotating body attached to the rotating shaft of the spindle motor, a driven side rotating body attached to the joining tool, and a joining means for joining the driving side rotating body and the driven side rotating body. A robot-type friction stirring joining device characterized in that the turning power generated by the rotation of the spindle motor is indirectly transmitted to the joining tool by the turning power transmission means. The robot-type friction stir welding device according to claim 1.
A spindle motor is placed inside the spindle,
A robot-type friction stir welding apparatus characterized in that by directly connecting the rotating shaft of the spindle motor to the joining tool, the rotational force generated by the rotation of the spindle motor is directly transmitted to the joining tool. The robot-type friction stir welding apparatus according to claim 2 or 3.
In the stage before starting the friction stir welding of the member to be joined, after teaching the friction stir welding unit to the joint position of the member to be joined by driving each joint portion of the articulated robot arm, the friction stir welding unit is taught.
By driving the Z-axis vertical drive motor to drive the spindle downward, the joining tool can be inserted into a desired insertion position of the member to be joined without requiring the excitation of the articulated robot arm. A robot-type friction stir welding device that features it. The robot-type friction stir welding apparatus according to claim 4.
The target load factor of the spindle motor and the target drive amount of the Z-axis vertical drive motor are set.
The Z-axis vertical drive motor is driven to move the spindle downward in the Z-axis, and the insertion process of inserting the joining tool into the member to be joined is started while being rotated by the spindle motor at a predetermined rotation speed. death,
When either the first insertion processing end condition set based on the target load factor or the second insertion processing end condition set based on the target drive amount is satisfied, the insertion process is terminated. A robot-type friction stir welding device characterized by this. The robot-type friction stir welding apparatus according to claim 5.
In a predetermined sampling cycle, the current load factor indicating the current load factor of the spindle motor and the current load factor indicating the current value of the drive amount of the Z-axis vertical drive motor are acquired, and the sampling cycle is obtained. In, it is determined whether or not the first deviation between the current load factor and the target load factor has reached the first permissible range.
When it is determined that the first deviation has reached the first permissible range, the first insertion processing end condition is satisfied.
It is determined whether or not the second deviation between the current drive amount and the target drive amount has reached the second allowable range.
A robot-type friction stir welding apparatus characterized in that when it is determined that the second deviation has reached the second permissible range, the second insertion processing end condition is satisfied. The robot-type friction stir welding device according to claim 6.
A robot-type friction stir welding apparatus characterized in that after confirming the satisfied state of the first insertion process end condition, the satisfied state of the second insertion process end condition is confirmed. The robot-type friction stir welding device according to claim 7.
A robot-type friction stir welding apparatus characterized in that after the insertion process is completed, the process shifts to a friction stir welding process in which the member to be welded is friction stir welded by the bonding tool. The robot-type friction stir welding device according to claim 6.
Set the damage detection load factor and the damage detection drive amount,
The Z-axis vertical drive motor is driven to move the spindle downward to the Z-axis, and the insertion process of inserting the joining tool into the member to be joined while rotating the joining tool at a predetermined rotation speed by the spindle motor is started. death,
A robot type characterized in that damage to the probe of the joining tool is detected when the current load factor does not reach the damage detection load factor at the time when the current drive amount reaches the damage detection drive amount. Friction stir welding device. The robot-type friction stir welding apparatus according to claim 9.
As the target load factor, one of the load factor of the spindle motor, the load factor of the Z-axis vertical drive motor, and the actual load of the spindle support portion is set.
For the current load factor, when the load factor of the spindle motor is set as the target load factor, the current value of the load factor of the spindle motor is used.
When the load factor of the Z-axis vertical drive motor is set as the target load factor, the current value of the load factor of the Z-axis vertical drive motor is used.
When the actual load of the spindle support portion is set as the target load factor, the current value of the actual load of the spindle support portion is used.
When the load factor of the spindle motor is set as the target load factor, the damage detection load factor is set by the load factor of the spindle motor.
When the load factor of the Z-axis vertical drive motor is set as the target load factor, it is set by the load factor of the Z-axis vertical drive motor.
A robot-type friction stir welding apparatus characterized in that when the actual load of the spindle support portion is set as the target load factor, the actual load of the spindle support portion is set. A method of inserting a joining tool into a member to be joined by the robot-type friction stir welding device according to claim 1.
(A) In the step before starting the friction stir welding of the members to be joined, a step of teaching the friction stir welding unit to the joining position of the members to be joined by driving each joint portion of the articulated robot arm.
(B) After the step (a), a target value setting step for setting the target load factor of the spindle motor and the target drive amount of the Z-axis vertical movement drive motor, and
(C) After the step (b), the Z-axis vertical drive motor is driven to move the spindle downward on the Z-axis, and the joining tool is rotated by the spindle motor at a predetermined rotation speed. It has a step of executing an insertion process to be inserted into a member to be joined, and has.
In step (c) above
(C1) A state in which the current load factor indicating the current value of the load factor of the spindle motor and the current loading amount indicating the current value of the driving amount of the Z-axis vertical drive motor are acquired in a predetermined sampling cycle. Amount acquisition step and
(C2) A method for inserting a joining tool, further comprising a comparison step of comparing the current load factor and the target load factor, and then comparing the current load factor and the target load factor. The method for inserting the joining tool according to claim 11.
In the step (c2), the deviation between the current load factor and the target load factor reaches within a predetermined allowable range, or the deviation between the current drive amount and the target drive amount is within a predetermined allowable range. A method for inserting a joining tool, which comprises ending the insertion process of the step (c) when any one of the above conditions is satisfied.

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