JP2002292478A - Processing and controlling method using friction and agitation, processing and controlling device, and computer program for executing method therefor, and storage media storing computer program therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manage processing conditions of members side by side with processing times and to dispense with separate inspection steps. SOLUTION: In the step S55, the bonding portion area is calculated by assigning the calorific values computed in the step S49 into the calculating formula of the calorific values and the bonding portion area obtained in advance through experiments to obtain the bonding portion area. In the step S53, the plate thickness reduction volume calculated in the step S47 is judged if the volume stays within the prescribed standard value, and if the volume is within the standard value, the intensity criteria of the bonding portion area is conducted in the step S57 and if the volume goes beyond the standard value, judgment of quality guarantee 'impossible' is given. In the intensity judgment of the bonding portion area in the step S57, the bonding portion area is judged if within the standard value from the bonding characteristics file stored in advance and if within the standard value, quality guarantee is judged 'possible' and bonding is completed and if over the standard value, quality guarantee is judged 'impossible' since securing bonding strength is difficult.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a processing management method and apparatus using friction stir for joining metal members such as castings and plates by friction and agitation by friction, a processing management apparatus, a computer program for executing the method, and a computer program. The present invention relates to a storage medium storing a computer program.

[0002]

2. Description of the Related Art In the conventional joining technique, a sheet material or a metal member preformed in a three-dimensional shape is overlapped and joined by electric resistance welding, arc welding, adhesive, bolt fastening, rivets, or the like.

[0003] When the metal member has a complicated three-dimensional shape, spot welding that can be locally joined to a plurality of joints is used.

[0004] As another joining technique, a joining method of friction stirring in a non-molten state is disclosed in Japanese Patent No. 2712838. In this joining technique, a projection called a probe is inserted and translated while rotating a joining surface where two members are joined to each other, and the metal structure near the joining surface is plasticized by frictional heat and joined.

Japanese Patent Application Laid-Open Nos. Hei 10-183316 and 2000-15426 disclose a rotary tool provided with a protruding portion at a shoulder portion at a tip in a surface treatment of a casting such as a mating surface of a cylinder head with a cylinder block. There is disclosed a surface treatment method in which press-fitting is performed while rotating and stirring is performed in a non-molten state by heat.

[0006]

In the friction stir welding in the non-molten state, if the rotational speed of the tool, the tool pushing amount, the tool advancing speed, and the like are excessively increased, the welding may be incomplete or the welding portion may not be formed. Melts. For this reason, there is a limit in shortening the processing time.

Further, in the above-mentioned conventional joining technique, control parameters such as the number of rotations of the tool and the amount of press-in of the tool which are optimal for the thickness of the member and the material are obtained by conducting experiments in advance, so that the design is performed. In order to join a member different from the conventional one due to a change or the like, it is necessary to again obtain an optimal control parameter by an experiment or the like. In addition, quality evaluation such as joining strength is performed by a tensile test or the like using actually joined samples, and an additional inspection step is required.

[0008] Therefore, if the quality evaluation of the actually joined members can be performed in parallel at the time of joining using control parameters and the like, the quality of the members can be evaluated for each processing, and mass production can be appropriately dealt with. Furthermore, it is possible to easily calculate the optimum control parameters when joining members different from the conventional ones due to design changes and the like, which is very useful for suppressing the occurrence of defective products and improving the yield. .

However, to date, a system for evaluating the above-described quality in friction stir welding has been described.
It has not been developed.

[0010] The present invention has been made in view of the above problems, and an object thereof is to manage a processing state of a member in parallel with processing.
An object of the present invention is to provide a processing management method using friction agitation that does not require a separate inspection step, a processing management apparatus, a computer program for executing the method, and a storage medium storing the computer program.

[0011]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems and achieve the object, a method and an apparatus for processing management using friction stirring according to the present invention rotate a rotary tool and stir members by friction. A processing management method for performing processing by detecting the heat generation state of the member at the time of the processing, detecting the pressed state of the rotating tool with respect to the member, the processing state of the member from the heat generation state and the pressed state. To detect.

Preferably, in the heat generation state, a heat generation amount is calculated based on a dynamic friction coefficient of the member and a load on the member, and in the pushed state, the rotating tool is moved up and down with respect to the member. The pushing amount is calculated based on the encoder output of the motor.

Preferably, the processing is performed by rotating the rotary tool, superimposing at least two members and agitating by friction, and joining the members to determine whether or not the joined state of the members is good. Judge from the state.

Preferably, there is provided a processing management device for processing by rotating a rotary tool to stir the member by friction, wherein heat generation detecting means for detecting a heat generation state of the member at the time of the processing; The rotary tool includes a pressing detection unit that detects a pressed state of the rotary tool, and a processing detection unit that detects a processing state of the member from the heat generation state and the pressed state.

A computer program for executing the processing management method and a storage medium storing the program code are supplied to a computer, and the computer reads the program code stored in the storage medium, and reads the program code. Processing management processing may be executed.

[0016]

As described above, according to the first and fourth aspects of the present invention, when the rotary tool is rotated and the member is agitated by friction, the heat generation state of the member during the processing is detected. By detecting the pressed state of the rotating tool against the member and detecting the processing state of the member from the heat generation state and the pressed state, the processing state of the member can be managed in parallel with the processing, and a separate inspection process is not required. .

According to the second aspect of the present invention, in the heat generation state, the heat generation amount is calculated based on the dynamic friction coefficient of the member and the load on the member, and in the pushed state, the motor for moving the rotary tool up and down with respect to the member is operated. By calculating the pushing amount based on the encoder output, the processing state of the member can be managed using the control parameters used during the processing.

According to the third aspect of the present invention, the processing is performed by rotating a rotary tool, superimposing at least two members and agitating them by friction, and joining the members. By judging from the state, the quality of joining of the members can be managed using the control parameters used during joining.

According to the fifth and sixth aspects of the present invention, when the rotary tool is rotated to agitate the member by friction, the heat generation state of the member at the time of processing is detected, and the rotary tool is pushed into the member. A computer program for controlling a computer to execute a processing management method for detecting a state and detecting a processing state of a member from a heat generation state and a pressed state and a storage medium storing the program code is supplied to the computer. Read the program code stored in the storage medium by the computer,
By executing the processing management method, the same effect as the method can be obtained, and the method can be used for general purposes.

[0020]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

The embodiment described below is an example as a means for realizing the present invention, and the present invention can be applied to a modification or modification of the following embodiment without departing from the gist thereof. . [Joining Method by Friction Stirring] FIG. 1 is a conceptual diagram illustrating a joining method by friction stirring of an embodiment according to the present invention.

As shown in FIG. 1, the joining method exemplified in this embodiment is applied to joining of plate-like members made of, for example, an aluminum alloy, and at least two members are overlapped to form an outermost surface. The rotary tool 1 is pressurized and pressed into the first member W1 while rotating (turning) around the axis of the first member W1, so that the overlapped first and second members W
1. The member structure between W2 is melted and stirred by frictional heat and joined.

Then, the first and second members W1 and W2 are arranged opposite to the rotary tool 1 so as to be sandwiched by the rotary tool 1, and the fixed tool 10 is arranged so that the distance from the rotary tool 1 is variable. Is provided.

The rotary tool 1 is a non-wear type tool formed of a steel material (hard metal or the like) having a higher hardness than the member.
The member is not limited to an aluminum alloy as long as the material is softer than the rotating tool 1. The fixing tool 10 is formed from, for example, a steel material or a copper material.

More specifically, the rotating tool 1 has a first
The rotating tool 1 is provided with a projecting portion 3 projecting from the shoulder portion 2 and rotating the rotating tool 1 at a set number of rotations so as to sandwich the first and second members W1 and W2 between the rotating tool 1 and the fixed tool 10. 2 with the first and second members W
1 and W2, and the protruding portion 3 rotates inside these members, thereby cutting the member structure in the peripheral portion thereof to generate heat. Further, the facets cut by the protruding portion 3 are held inside the member by the two tools 1 and 10 and are agitated and collide with the surrounding member structure and the protruding portion 3 to generate heat, and the first shoulder portion 2 is heated. The cut face is melted by press-fitting and rotating at a predetermined pressure to melt the facets, and while promoting plastic flow of the member structure in the periphery, the unit area is maintained at a predetermined pressure and rotation speed for a predetermined time. The plastic pressure is increased by increasing the contact pressure, and the plastic structure is cooled and joined by pulling the rotating tool 1 out of the member while rotating it.

Further, by continuously performing this joining process, the member structure adhered to the peripheral portion of the protruding portion 3 in the previous cycle is melted and supplied as a material in the next cycle of stirring.

At this time, while reducing the area of the receiving surface 11 of the fixing tool 10, the pressing force is increased, the heat radiation to the fixing tool 10 is suppressed, the plastic flow volume is increased, and the joining force of the members is increased. .

The joining method according to the present embodiment employs a lap joint (for example, an outer panel of a rear door and a reinforcement) such as an automobile steel plate which is press-formed into a three-dimensional shape in advance.
It is suitable for local joining. That is, for a joint portion having a plurality of dots where the member has a complicated three-dimensional shape due to press molding and the rotating tool 1 cannot be continuously moved,
By using the bonding method of this embodiment, bonding can be performed locally, and bonding can be performed even after press molding.

According to this joining method, the welding current, cooling water, air and the like used in the conventional spot welding are not required at all, and the energy consumption required for joining can be greatly reduced. In addition, since the above-described devices and equipment as energy sources are not required, it is possible to significantly reduce capital investment.

Further, the conventional welding gun used for spot welding can be used, and it is possible to easily achieve the same or higher performance as the conventional ones in the restriction of the joining members, the joining strength and the production efficiency.

FIG. 2 is a conceptual diagram for explaining a conventional non-melting joining method by friction stirring.

In the conventional joining method shown in FIG. 2, the first and second members W1 and W2 are arranged so as to be sandwiched between the rotating tool 1 and the fixed tool 10 ', and the rotating tool is attached to the outermost first member W1. The procedure of press-fitting while rotating about its axis is the same as that of the present invention, but the member structure between the superimposed first and second members W1 and W2 is in a non-melted state due to frictional heat. In that they are agitated and joined.

Here, the non-melting and stirring state means that the metal structure is softened by frictional heat at a temperature lower than the lowest melting point among the components or eutectic compounds contained in the base material. Means to stir.

In the conventional joining method, since the stirring is performed in a non-melting state, there is an advantage that problems such as thermal distortion generated by electric resistance welding or the like are solved.

On the other hand, the rotational speed and pressing force of the rotary tool 1 cannot be increased unnecessarily due to frictional stirring without melting, and the area of the receiving surface 11 ′ of the fixed tool 10 ′ in contact with the second member W 2. Is larger than the area of the protruding portion 3 protruding from the tip of the rotary tool 1, so that the pressing force is distributed over the entire surface of the receiving surface 11 ', and the frictional heat due to the rotation of the rotary tool 1 is generated on the receiving surface 11'. There is a demerit that it takes time (for example, 2 to 3 seconds) for bonding due to heat radiation to the entire surface.

On the other hand, in the present invention, the rotational speed and pressure of the rotary tool 1 can be increased for frictional stirring in a molten state, and the receiving surface 11 of the fixed tool 10 is rotated at least. The projecting portion 3 of the tool 1 is formed smaller than the cross-sectional area to suppress heat radiation and increase the heat storage efficiency inside the member, thereby promoting the melting and plastic flow of the facets and the time required for joining (for example, 0.1 mm). 3 to 0.5
Second) can be shortened.

In addition, the protrusion 3 of the rotary tool 1 is
As shown in FIG. 4, since the total thickness of the members increases as the number of superposed members increases, it is necessary to increase the total thickness according to the number of superimposed members. For example, as shown in FIG.
When the rotating tool 1 having the projection 3 having a length for two lap joints is applied to three lap joints, if the joining time is shortened, the stirring amount of the intermediate member W2 and the lower member W3 becomes insufficient. If the joining time is lengthened, the thickness reduction of the upper member W1 becomes too large, and the strength between the upper member W1 and the intermediate member W2 cannot be secured. (See FIG. 4B) In any case, a tool used when the number of superposed members is small cannot be used for joining a large number of members.

Therefore, in the present invention, as shown in FIGS. 5 and 6, a second diameter which is concentric and has a small diameter so as to form at least one step is formed from the tip of the rotary tool 1 toward the protruding portion 3. By providing the third shoulder portions 4 and 5, the length of the protruding portion 3 can be changed to two or more, and three or more or a large total plate thickness can be joined.

Considering the state of pressurization from the fixing tool 10 at the time of joining, when the receiving surface 11 shown in FIG. 7 is flat, stress concentrates on the corners 12 thereof and is applied to the member W of the fixing tool 10. The amount of subsidence increases. Therefore, in the present invention, as shown in FIG. 8, the receiving surface 11 of the fixing tool 10 is formed into a curved surface so that the corner 12 is formed smoothly, thereby reducing stress concentration on the member W and reduction of sinking. ing. Also, by forming the receiving surface 11 in a curved shape, even if the angle of contact with the member W is slightly deviated, the receiving surface 11 can be configured so that the receiving surface is formed by a surface instead of a point or a line. Stable joining quality can be easily secured. [Rotating Tool Used for Joining] FIGS. 9 and 10 are external views of a rotating tool used for friction stir welding according to the embodiment of the present invention. FIG. 11 is a front view of a fixing tool used for friction stir welding according to the embodiment of the present invention.

The rotary tool shown in FIG. 9 is used for bonding having a relatively small total thickness of about two superimposed sheets, and has a cylindrical first shoulder portion 2 (corresponding to a first tool portion). And a cylindrical protrusion 3 (corresponding to a second tool portion) having a smaller diameter (or a smaller cross-sectional area) than the first shoulder portion 2 and protruding from the tip 2a of the first shoulder 2 with the same axis. And

The rotary tool shown in FIG. 10 is used for joining with three or more superposed sheets and a large total thickness. The rotary tool has a cylindrical first shoulder portion 2 and a first shoulder portion 2. Small diameter (or small cross-sectional area)
A cylindrical projection 3 projecting from the distal end 2a of the shoulder 2 at the same axis, and the diameter gradually decreases toward the projection 3 from the first shoulder 2 so as to be concentric and form a step. It has second and third cylindrical shoulder portions 4 and 5.

In the rotary tool shown in FIG. 9, the diameter φ of the first shoulder 2 is set to about 5 to 13 mm, and the diameter φ of the projection 3 is set to about 2 to 5 mm.

In the rotary tool shown in FIG. 10, the diameter φ of the first shoulder 2 is about 13 to 16 mm, the diameter φ of the second shoulder 4 is about 10 to 13 mm, and the diameter φ of the third shoulder 5 is 5 to 5 mm. About 10 mm, the diameter φ of the protrusion 3 is 2
It is set to about 5 mm.

Incidentally, a spiral or parallel groove may be formed on the outer peripheral surface of the protruding portion 3 in order to further improve the cutting property and the stirring property. In the case of a spiral groove, the groove may be formed in a direction in which the member tissue is pushed into the member.

The fixing tool 10 shown in FIG.
1 is provided with an enlarged diameter portion 13 which is formed in a tapered shape so that the cross-sectional area is increased from the rotation tool 1 to the anti-rotation tool side;
The (I portion) is formed in a curved shape with a radius of about R30 to 50 mm so as to absorb the displacement of the pressure application point with the protrusion 2.

As shown in FIG. 10 described above, by configuring the rotating tool, it is possible to perform joining of various numbers of sheets and total thickness without changing the tool. It is possible to reduce the loss of the joining time. Further, since the types of tools to be used are reduced, costs such as tool purchase / machining costs and maintenance costs can be reduced.

As shown in FIG. 11, in the fixing tool 10, the diameter φ of the receiving surface 11 is approximately 7 to 13 mm, the diameter φ of the large diameter portion of the enlarged diameter portion 13 is approximately 13 to 16 mm, and the diameter φ of the small diameter portion. Are tapered from the receiving surface 11 toward the enlarged diameter portion 13 according to the respective dimensions.

FIG. 12 is a front view showing a rotary tool and a mounting bracket for the rotary tool.

As shown in FIG. 12, a tapered hole 6 which is tapered is formed on the end face of the rotating tool 1 on the side opposite to the protruding portion 2 and is equally spaced around the tapered hole 6 (for example, around the axis).
The rotation-stop guide groove 7 is formed at every 0 °). The end surface of the mounting bracket 20 on the side of the rotating tool 1 is formed in a tapered shape, and the detent guide 2 is fitted around the tapered surface 21 in the detent guide groove 7.
2 are protruding.

Then, the tapered hole 6 of the rotary tool 1 and the detent guide groove 7 are fitted to the tapered surface 21 and the detent guide 22 of the mounting bracket 20, respectively, so that both are fixed. The guide 22 is configured so as not to rotate relative to each other by fitting.

The mounting bracket 20 is used for rotating tool 1
Are fixed to form an integral shaft having a diameter of approximately 13 to 16 mm, and the length thereof is set to a length suitable for a member to be joined. Also, the end surface of the mounting bracket 20 on the side opposite to the rotation tool has a diameter φ of 10 to 1 mm.
A robot mounting portion 23 of about 3 mm is extended, and the robot mounting portion 23 is mounted on a motor shaft of an articulated robot (not shown) via a holder or the like to be rotated and driven together with the rotary tool 1.

FIG. 13 is a schematic diagram of an articulated robot that fixes and drives a rotating tool.

As shown in FIG. 13, the articulated robot 30
Is connected to a joint 32 provided on a base 31 and swings about a y-axis, and is rotated by a joint 33 about a z-axis. The first arm 34 is connected to the first arm 34 via a joint 35. A second arm 37 that pivots about the y-axis and rotates about the x-axis at a joint 36, and a third arm 39 that is connected to the second arm 37 via a joint 38 and pivots about the y-axis. Having.

The distal end of the third arm 39 has a joining gun 5
0 is attached. The rotary tool 1 is rotatably mounted on the joining gun 50, and a motor 51 for driving the rotary tool 1 to rotate and a fixed tool 10 are mounted to face the rotary tool 1. The distance between the rotary tool 1 and the fixed tool 10 is made variable by the actuator 52, and is configured so that it can be applied to three or more overlapping joints by controlling the pressing force on the members at the time of joining and the number of rotations of the tool. I have.

Each arm, motor,
The operation of the actuator is controlled in advance by the robot control unit 60 via the power / control cable 61 after teaching.

FIG. 14 is a detailed view of the joining gun shown in FIG.

As shown in FIG. 14, the joining gun 50 has a lower arm 5 extending laterally from the lower end of the gun arm 55.
6, the fixing tool 10 is mounted via a mounting bracket 57.

A driving unit 5 for rotating and vertically driving the rotary tool 1 is provided at the upper end of the gun arm 55.
8 is attached. The drive unit 58 includes a guide table 53 that is vertically guided by a ball screw mechanism 54 that uses a vertical drive motor 52 as a drive source. The rotation drive motor 51 is fixed to the guide table 53. The rotating tool 1 is attached to a rotating shaft 51 a of the rotating drive motor 51 via a holder or the like, and is arranged so as to face the fixed tool 10.

The rotary tool 1 is provided with a guide table 53 by a vertical drive motor 52 and a ball screw mechanism 54.
Is moved up and down by the movement of.

In the present embodiment, a joining defect caused by an equipment abnormality is prevented based on control parameters of the joining equipment (joining gun, rotary drive motor, up / down drive motor, rotary tool, etc.), and a member to be joined is prevented. The calorific value is calculated from the dynamic friction coefficient and the load applied to the member (pressure, rotation speed, tool contact diameter, etc.), and welding is performed based on the relationship between the calorific value and the amount of pushing of the rotating tool into the member (thickness reduction). It is configured to judge the joining quality in a non-destructive manner, so that all the joints can be inspected nondestructively, and it is possible to judge the quality assurance in the production line (in-line). [Joining Control] Next, a description will be given of a joining control method by friction stirring in the present embodiment.

FIG. 15 is a flowchart illustrating a joining control method using friction stirring in the present embodiment.

As shown in FIG. 15, in step S1,
Based on the combination of the materials to be joined and the plate thickness, suitable joining conditions are calculated from a database in which the joining conditions such as the number of rotations of the rotary tool, the pressing force, the joining time and the like are set in advance through experiments and the like.

In step S3, the rotation drive of the rotary tool is started.

In step S5, the control waits until the rotating tool reaches the set number of revolutions.
Proceeding to 7, the rotating tool is lowered to start pressurizing the member. The tool rotation speed is calculated from the encoder value of the rotation drive motor. The pressing force is calculated from the feedback current value of the vertical drive motor. Further, the distance between the rotating tool and the fixed tool is calculated from the gun arm deflection correction table set in advance by an experiment or the like and the encoder value of the vertical drive motor.

In step S9, when the rotating tool reaches the set pressing force and when the press-fitting of the projecting portion of the rotating tool into the member is detected from the distance between the tools, the shoulder of the rotating tool comes into contact with the member. It generates heat by rotating in a state.

In step S11, the position of the tool tip (the amount of pushing) with respect to the member of the projecting portion 2 is calculated, and
In step S13, a load applied to the rotating tool is calculated.

The tool tip position (depression amount) of the rotary tool is calculated from the distance between the tools. Further, the load applied to the rotary tool is calculated from the feedback current value of the rotary drive motor.

In step S15, the amount of reduction in the thickness of the upper member is calculated while monitoring the distance between the tools, and when the value exceeds a predetermined reference value, the joining conditions (pressing force, rotation speed) are corrected or changed. Thus, a reduction in the thickness of the sheet, which may cause a joining failure (decrease in joining strength), is reduced. Step S13
Correct or change the joining conditions (pressing force, number of rotations) so as to be suitable for the tool tip position of the rotating tool calculated in step (1).

In step S17, under the joining conditions corrected (changed) in step S15, the joining processes of steps S13 to S17 are held until the joining time set in step S1 is reached. Complete.

The above-mentioned pressurizing force is controlled by setting in advance a relation between the pressurizing force at the tool tip and the current value of the vertical drive motor required at that time in a table, and calculating a pressurizing force correction formula from this table. Have been. Then, the feedback current of the vertical drive motor at the time of pressurization is detected, and the pressing force can be calculated from the feedback current value and the pressing force correction formula.

As shown in FIG. 19, the tool tip position (depression amount) of the rotary tool is, as shown in FIG. 19, the encoder value of the vertical drive motor at the reference position at the time of checking the loss, and the encoder value of the motor at the current rotary tool position. It is calculated by comparing with the encoder value. As for the distance between the tools, as shown in FIG. 19, the relationship between the pressing force and the deflection amount of the gun arm is set in a table in advance, a deflection correction formula is obtained from this table, and the pressing force generated at the time of joining is determined by the vertical drive motor. And the deflection amount of the gun arm when pressurized by the pressing force is calculated from the deflection correction formula. Then, the inter-tool distance is calculated from the relationship between the amount of deflection of the gun arm and the position of the tool tip of the rotary tool.

In the above control, the joining time may be changed according to the load applied to the rotary tool.

According to the above embodiment, the joining state is detected from the position of the tool tip and the load, and the joining conditions (pressing force, rotation speed, joining time) suitable for the joining state are controlled. By generating a plastic flow suitable for the combination of the thickness and the plate thickness, it is possible to reduce joining defects and secure stable joining quality. [Quality Assurance Method] Next, a quality assurance method in the joining method by friction stir according to the present embodiment will be described.

FIG. 16 is a flowchart illustrating a quality assurance method in the friction stir welding method according to the present embodiment.

As shown in FIG. 16, in step S21, a position where the protruding portion 2 of the rotary tool 1 comes into contact with the member without intervening the member is calculated before the actual joining.

In step S23, the above-mentioned step S21
By comparing the contact position calculated in step (1) with a predetermined reference position, a check is made to confirm the loss of the protruding portion 2 of the rotary tool 1 due to wear.

The reference position is a position when a new rotary tool 1 with no loss is used and the rotary tool 1 comes into contact with the fixed tool 10 and a predetermined pressure is applied. When the contact position exceeds the reference position by a predetermined amount, it is determined that there is a loss.

If it is determined in step S23 that the protruding portion 2 is missing, the process proceeds to step S25, where the subsequent robot operation is stopped as abnormal.

If it is determined in the step S23 that there is no loss in the loss confirmation, the program is started in a step S27 to start the joining process.

In step S29, the rotation of the rotary tool is started.

If the rotational speed of the rotary tool has reached the set number of revolutions from the encoder value of the rotary drive motor in step S33, the process proceeds to step S37, in which the rotary tool 1 is lowered to start pressurizing the members. If the set number of rotations has not been reached even after the elapse of the predetermined time, step S35
, The subsequent robot operation is stopped.

When the rotating tool reaches the set pressing force in step S39, the rotating tool rotates while the shoulder portion of the rotating tool is in contact with the member and starts heating.
At 43, the tool tip position (depression amount) with respect to the member of the protruding portion 2 is calculated, and at step S45, the load applied to the rotating tool is calculated. If the set pressure has not been reached even after the elapse of the predetermined time, the robot operation is stopped in step S41 as an abnormality.

The above-mentioned pressurizing force is controlled by setting in advance a relation between the pressurizing force at the tool tip and the current value of the vertical drive motor required at that time in a table, and calculating a pressurizing force correction formula from this table. Have been. Then, the feedback current of the vertical drive motor at the time of pressurization is detected, and the pressing force can be calculated from the feedback current value and the pressing force correction formula.

As shown in FIG. 19, the tool tip position (depressed amount) of the rotary tool is, as shown in FIG. 19, the encoder value of the vertical drive motor at the reference position at the time of checking the loss and the encoder value of the motor at the current rotary tool position. It is calculated by comparing with the encoder value. As for the distance between the tools, as shown in FIG. 19, the relationship between the pressing force and the deflection amount of the gun arm is set in a table in advance, a deflection correction formula is obtained from this table, and the pressing force generated at the time of joining is determined by the vertical drive motor. And the deflection amount of the gun arm when pressurized by the pressing force is calculated from the deflection correction formula. Then, the inter-tool distance is calculated from the relationship between the amount of deflection of the gun arm and the position of the tool tip of the rotary tool.

Further, the load applied to the rotary tool is obtained by setting a reference current for each rotation speed in advance in a table based on the relationship between the feedback current value of the rotation drive motor in an unloaded state and the rotation speed detected by the encoder of the rotation drive motor. Is calculated from this table, and the reference current calculated from the reference current calculation formula and the feedback current value of the rotary drive motor at the time of joining are calculated from the following relational expression 1. (Equation 1) Load at the time of joining = feedback current value of the rotary drive motor at the time of joining−reference current At step S47, pressurization is performed based on the tool tip position of the rotary tool and a previously stored joining characteristic file (see FIG. 18). The thickness reduction of the member is calculated.

In step S49, the amount of heat generated by friction stirring is calculated from the load or pressure, the number of rotations of the tool, the surface resistance (dynamic friction coefficient) of the member, and the tool contact diameter.

In step S51, the joining quality is determined while monitoring the above-mentioned thickness reduction and the amount of heat generation. If it is determined that the quality cannot be guaranteed when the joining is completed, the operator is warned of a joining defect and repaired. . The above-mentioned thickness reduction becomes a factor that determines the magnitude of the joining strength. This is because the magnitude of the remaining plate thickness after joining greatly affects the joining strength.

The above-mentioned thickness reduction amount is a value obtained by subtracting the distance between tools from the total thickness, and the total thickness reduction amount is calculated by adding the total thickness reduction amount to the thickness reduction ratio (the thickness reduction amount of the upper member / total thickness). (Thickness reduction)
To calculate the amount of reduction in the thickness of the upper member. Further, the sheet thickness reduction amount of the lower member is calculated by subtracting the sheet thickness reduction amount of the upper member from the total sheet thickness reduction amount (see the following relational expressions 2 to 4). As the sheet thickness reduction ratio, a ratio obtained in advance by an experiment or the like is set. (Equation 2) Total thickness reduction = Total thickness-tool distance (Equation 3) Thickness reduction of upper member = Total thickness reduction x Thickness reduction ratio (Thickness reduction of upper member / Total thickness) (Equation 4) Thickness reduction of lower member = Total thickness reduction−Thickness reduction of upper member FIG. 18 shows the relationship between the pressing force and the joining strength, and joining conditions A, B, and C It is determined that quality assurance is possible when the bonding strength exceeds the lower limit value, and that quality assurance is not possible when the bonding strength falls below the lower limit value. [Joining Quality Judging Method] Next, the joining quality judging method in step S51 will be described.

FIG. 17 is a flowchart illustrating a quality assurance method in the friction stir welding method according to the present embodiment.

As shown in FIG. 17, in step S55, the heat generation amount calculated in step S49 is substituted into a heat generation amount previously calculated by an experiment or the like and a formula for calculating the joint area (or diameter or the like) to join the joint. Calculate the area. At the same time, in step S53, it is determined whether the thickness reduction calculated in step S47 is within a preset reference value,
If the value is within the reference value, the strength of the joint area is determined in step S57. If the value exceeds the reference value, it is determined that it is difficult to secure the bonding strength and quality assurance is determined to be impossible. I do.

In the determination of the strength of the joint area in step S57, it is determined whether or not the joint area is within a reference value from a joint characteristic file stored in advance (see FIG. 18). If the joining exceeds the reference value, it is determined that it is difficult to secure the joining strength, and it is determined that the quality cannot be assured.

As can be seen from FIG. 18, as the pressing force increases, the joining strength decreases from a certain point P.
This is because the amount of reduction in the plate thickness increases and affects the joining strength, and the joining condition (pressing force, rotation speed) is determined using the point P at which the joining strength decreases as a reference value.

According to the above embodiment, it is possible to detect a joining defect caused by an equipment abnormality from the control parameters of the joining equipment (joining gun, rotary drive motor, vertical drive motor, rotary tool, etc.). In addition, the calorific value is calculated from the dynamic friction coefficient of the members to be joined and the load applied to the members (pressure, rotation speed, tool contact diameter, etc.), and the calorific value and the amount of the rotating tool pushed into the member (the amount of reduction in plate thickness) By judging the joining quality during the joining from the relationship, non-destructive inspection can be performed for all the joinings, and it is possible to judge the quality assurance in the production line (in-line). [Continuous Joining] In the above embodiment, an example of overlap joining in which the rotating tool 1 is not moved by pressing the rotating tool 1 to the joining portion has been described. You may join continuously, making it. [Surface Treatment] The joining technique of this embodiment can be applied to the surface treatment of a metal member.

In the surface treatment, a casting made of an aluminum alloy is used. In particular, the casting is used for surface modification of an adjacent port (an inter-valve portion) formed in a cylinder head of an automobile, a piston, a brake disk, and the like. By melting and agitating the surface modified region of the casting by frictional heat, the metal structure is refined, the eutectic silicon (Si) particles are uniformly dispersed, casting defects are reduced, and thermal fatigue (low cycle fatigue) is achieved. Material properties such as life, elongation, impact resistance, and the like can be obtained that are superior to those of conventional remelt processing.

A computer program for executing the joining control method, the joining assurance method, and the joining quality judging method corresponding to the flowcharts shown in FIGS. 15 to 17 and a storage medium storing the program code are supplied to the computer. Then, the computer may read out the program code stored in the storage medium and execute the processing of the above embodiment.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram illustrating a joining method by friction stirring according to an embodiment of the present invention.

FIG. 2 is a conceptual diagram illustrating a conventional non-melting joining method by friction stirring.

FIG. 3 is a diagram showing a state of joining with a rotating tool having three protrusions having a length for overlapping joining.

FIG. 4 is a diagram showing a state of joining when three sheets are overlapped and joined by changing the time using a rotating tool having a protrusion having a length for two sheets to be joined.

FIG. 5 is a diagram illustrating a state of joining when two sheets are overlapped and joined by the rotating tool according to the embodiment of the present invention.

FIG. 6 is a diagram showing a state of joining when three sheets are overlapped and joined by the rotary tool according to the embodiment of the present invention.

FIG. 7 is a diagram showing an influence on a member by pressing of a fixing tool having a flat receiving surface.

FIG. 8 is a diagram illustrating an influence on a member due to pressurization of a fixing tool having a curved receiving surface.

FIG. 9 is an external view of a rotary tool used for friction stir welding according to the embodiment of the present invention.

FIG. 10 is an external view of a rotary tool used for friction stir welding according to the embodiment of the present invention.

FIG. 11 is a front view of a fixing tool used for friction stir welding according to the embodiment of the present invention.

FIG. 12 is a front view showing a rotating tool and a mounting bracket of the rotating tool.

FIG. 13 is a schematic view of an articulated robot that fixes and drives a rotating tool.

FIG. 14 is a detailed view of the joining gun shown in FIG.

FIG. 15 is a flowchart illustrating a welding control method using friction stirring according to the present embodiment.

FIG. 16 is a flowchart illustrating a quality assurance method in the friction stir welding method according to the embodiment.

FIG. 17 is a flowchart illustrating a quality assurance method in the friction stir welding method according to the embodiment.

FIG. 18 is a diagram illustrating a relationship between a pressing force and a bonding strength.

FIG. 19 is a diagram illustrating a relationship between a tool tip position, a distance between tools, and a deflection amount of a gun arm.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rotary tool 3 Projection part 10 Fixed tool 30 Articulated robot W1-W3 Member

Claims (6)

[Claims] 1. A machining management method for machining a member by rotating a rotating tool and stirring the member by friction, wherein a heat generation state of the member at the time of the machining is detected, and a pushing state of the rotating tool with respect to the member is determined. And detecting a processing state of the member from the heat generation state and the pressed state. 2. The heating state is calculated based on a coefficient of dynamic friction of the member and a load on the member. The pushing state is an encoder of a motor for moving the rotary tool up and down with respect to the member. The method according to claim 1, wherein the pushing amount is calculated based on the output. 3. The processing is performed by rotating the rotating tool, superimposing at least two members and agitating them by friction, and joining the members by judging whether or not the joining state of the members is good from the working state. The process management method using friction stirring according to claim 1 or 2, wherein the process is performed. 4. A processing management apparatus for processing by rotating a rotary tool to stir a member by friction, comprising: a heat generation detecting unit for detecting a heat generation state of the member during the processing; and the rotation tool for the member. And a processing detecting means for detecting a processing state of the member from the heat generation state and the pressing state. 5. A computer program for controlling a computer to execute the processing management method according to claim 1. 6. A storage medium storing a program code for controlling a computer to execute the processing management method according to claim 1.