JP4671523B2 - Process management method and process management apparatus using friction stirring - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a processing management method, a processing management apparatus, a computer program for executing the method, and a storage medium storing the computer program, which use friction stir to melt and stir metal members such as castings and plates by friction and join them together. About.
[0002]
[Prior art]
In the conventional joining technique, a plate material or a metal member press-molded in advance into a three-dimensional shape is superposed and joined by electric resistance welding, arc welding, adhesive, bolt fastening, rivet or the like.
[0003]
And when a metal member is a complicated three-dimensional shape, the spot welding which can be joined locally with respect to the joint part which has multiple points is used.
[0004]
As another joining technique, Japanese Patent No. 2712838 discloses a joining method in which friction stirring is performed in a non-molten state. In this joining technique, a protrusion called a probe is inserted and translated on a joining surface where two members are butted together, and the metal structure in the vicinity of the joining surface is plasticized by frictional heat and joined.
[0005]
Further, in JP-A-10-183316 and JP-A-2000-15426, in the surface treatment of a casting such as a mating surface of a cylinder head with respect to a cylinder block, while rotating a rotary tool provided with a protruding portion on a shoulder portion at the tip. A surface treatment method is disclosed in which the mixture is pressed and stirred in a non-molten state by heat.
[0006]
[Problems to be solved by the invention]
In the friction stir welding in the non-molten state, if the tool rotation speed, the tool push-in amount, the tool traveling speed, etc. are increased excessively, the joining becomes incomplete or the joined portion is melted. For this reason, there was a limit to shortening the processing time.
[0007]
Furthermore, in the above conventional joining technique, by performing experiments and the like in advance, control parameters such as the optimum tool rotation speed and tool push-in amount for the member thickness and material are obtained. In order to join a member different from the conventional one, it is necessary to obtain an optimum control parameter by an experiment again. In addition, quality evaluation such as bonding strength is performed by a tensile test using a sample that is actually bonded, and a separate inspection process is required.
[0008]
Therefore, if the quality evaluation of the actually joined member can be performed in parallel using the control parameters at the time of joining, the quality of the member can be evaluated for each processing, and it can be appropriately handled for mass production. Therefore, it is possible to easily calculate optimal control parameters when joining different members due to a design change or the like, and it is very useful for improving the yield by suppressing the occurrence of defective products.
[0009]
However, so far, a system for evaluating the above-described quality in friction stir welding has not been developed.
[0010]
The present invention has been made in view of the above problems, and an object of the present invention is to provide a processing management method, a processing management apparatus, and the method using friction stirrer that can manage the processing state of a member in parallel during processing and do not require a separate inspection step. And a storage medium storing the computer program.
[0011]
[Means for Solving the Problems]
  In order to solve the above-described problems and achieve the object, the present invention superimposes at least two members,The front end portion has a shoulder portion and a protruding portion protruding from the shoulder portion.A processing management method in which a rotary tool is rotated around its axis while being pressed and pushed into one member and agitated by friction to locally join the members,in frontRotation toolTip position of the protrusionDetectingTip positionOn the basis of theThe shoulder portion is caused by being pushed into the one member.Calculating a thickness reduction amount of the joint portion of the one member, and determining whether the joining strength is good or not based on the calculated thickness reduction amount.
  In the present invention, at least two members are superposed,The front end portion has a shoulder portion and a protruding portion protruding from the shoulder portion.A process management method in which a rotary tool is rotated around its axis while being pressed and pushed into one member, and is agitated by friction to locally join the members, wherein the one member and the rotary tool The coefficient of dynamic friction between the two membersSaidCalculating the amount of heat generation based on the load of the rotary tool;in frontRotation toolTip position of the protrusionAnd calculating the joint area based on the calorific value from a formula representing the relationship between the calorific value obtained in advance and the joint area between the members.Tip positionOn the basis of theThe shoulder portion is caused by being pushed into the one member.The thickness reduction amount of the joining portion of the one member is calculated, it is determined whether the thickness reduction amount is within a preset reference value, and if it is within the reference value, the joining is performed based on the joining area. And a step of determining whether the strength is good or bad.
[0014]
  In the present invention, at least two members are superposed,The front end portion has a shoulder portion and a protruding portion protruding from the shoulder portion.A processing management device that pressurizes and presses one member while rotating a rotating tool about its axis, stirs by friction, and locally joins the members,in frontRotation toolTip position of the protrusionDetectInspectionExit means; andTip positionOn the basis of theThe shoulder portion is caused by being pushed into the one member.A joining state detecting means for calculating a thickness reduction amount of the joining portion of the one member and judging whether the joining strength is good or not based on the calculated thickness reduction amount.
  In the present invention, at least two members are superposed,The front end portion has a shoulder portion and a protruding portion protruding from the shoulder portion.A processing management device that pressurizes and presses one member while rotating a rotating tool about its axis, and stirs it by friction to locally join the members, wherein the one member and the rotating tool A calorific value calculating means for calculating a calorific value based on a dynamic friction coefficient between the rotating tool and the load of the rotary tool on the one member at the time of joining;in frontRotation toolTip position of the protrusionDetectInspectionCalculating the junction area based on the heat generation amount from the formula representing the relationship between the output means and the calorific value obtained in advance and the joint area between the members;Tip positionOn the basis of theThe shoulder portion is caused by being pushed into the one member.The thickness reduction amount of the joining portion of the one member is calculated, it is determined whether the thickness reduction amount is within a preset reference value, and if it is within the reference value, the joining is performed based on the joining area. A joining state detecting means for judging whether the strength is good or bad..
[0015]
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 the processing management processing is performed. May be executed.
[0016]
【The invention's effect】
  According to the present invention,Calorific value of one member during joiningOr boardBy calculating the thickness reduction amount and determining the quality of the bonding strength from the calculated plate thickness reduction amount and the amount of heat generated, it is possible to determine the quality of the bonding of the members using the control parameters used during the bonding, Thus, the joining state of the members can be managed, and a separate inspection process becomes unnecessary.
[0017]
  Claims 3, 4,7According to the invention, the amount of pushing is the rotation toolOneCalculated based on the encoder output of the motor for raising and lowering the member,OneThe thickness reduction amount of the joint part of the member is calculated by rotating the tool pushed into one of the members and facing the rotary tool.The otherBased on the distance between the fixed tool that receives the memberBy calculating the total thickness reduction amount and multiplying the total thickness reduction amount by the thickness reduction ratio of one memberBy being calculated, the joining state of the members can be managed using the control parameters used during joining.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
[0021]
The embodiment described below is an example as means for realizing the present invention, and the present invention can be applied to a modified or modified embodiment described below without departing from the spirit of the present invention.
[Joint method by friction stirring]
FIG. 1 is a conceptual diagram illustrating a joining method by friction stirrer according to an embodiment of the present invention.
[0022]
As shown in FIG. 1, the joining method exemplified in the present embodiment is applied to joining of plate-like members such as an aluminum alloy, for example, and the first outermost surface is superposed by superposing at least two members. The member tool between the first and second members W1 and W2 is melted and agitated by frictional heat by pressurizing and press-fitting the rotating tool 1 around the axis of the member W1. To be joined.
[0023]
Then, the fixed tool 10 is provided so as to be opposed to the rotary tool 1 so that the first and second members W1 and W2 are sandwiched between the rotary tool 1 and the distance from the rotary tool 1 is variable. ing.
[0024]
The rotary tool 1 is a non-abrasion type tool formed of a steel material (hard metal or the like) having a higher hardness than the member. However, the member is not limited to an aluminum alloy as long as the member is a softer material than the rotary tool 1. Moreover, the fixed tool 10 is formed from a steel material, a copper material, etc., for example.
[0025]
  Specifically, the rotary tool 1 includes a protruding portion 3 that protrudes from the first shoulder portion 2 at the tip thereof, and is set so as to sandwich the first and second members W1 and W2 between the rotary tool 1 and the fixed tool 10. Projecting part while rotating the rotary tool 1 at the number of rotations3Is pressed into the first and second members W1 and W2 with a predetermined pressure, and the protrusion 3 rotates inside these members to cut the member structure of the peripheral portion and generate heat. Furthermore, the facet cut by the projecting portion 3 is held inside the member by both the tools 1 and 10 and is agitated to generate heat by colliding with the surrounding member structure and the projecting portion 3, and the first shoulder portion 2 is Unit area by holding for a predetermined time at a predetermined pressure and number of rotations while generating heat by press-fitting with a predetermined pressure and rotating to melt the facet and promoting plastic flow of the surrounding member structure By increasing the contact pressure and increasing the plastic flow volume, and pulling the rotary tool 1 from the member while rotating, the member structure that has been plastically flowed is cooled and joined.
[0026]
Furthermore, by performing this joining process continuously, the member structure | tissue adhering to the peripheral part of the protrusion part 3 by the previous cycle fuse | melts, and is supplied as a material by stirring of the next cycle.
[0027]
At this time, while reducing the area of the receiving surface 11 of the fixed tool 10, the applied pressure is increased, heat dissipation to the fixed tool 10 is suppressed, the plastic flow volume is increased, and the coupling force of the members is increased.
[0028]
The joining method of the present embodiment is suitable for local joining of lap joints (for example, an outer panel of a rear door and reinforcement) such as an automobile steel plate press-formed in a three-dimensional shape in advance. That is, by using the joining method of the present embodiment locally on a plurality of joint portions where a member has a complicated three-dimensional shape by press molding and the rotary tool 1 cannot be moved continuously. Bonding is possible, and bonding is possible even after press molding.
[0029]
According to this joining method, welding current, cooling water, air, and the like used in conventional spot welding are not required, and energy consumption required for joining can be greatly reduced. Moreover, since the apparatus and equipment as the energy source as described above are not required, the capital investment can be greatly reduced.
[0030]
Moreover, the welding gun used for the conventional spot welding can be diverted, and about the restrictions of a joining member, joining intensity | strength, and production efficiency, the capability equivalent to the past or more can be achieved easily.
[0031]
FIG. 2 is a conceptual diagram for explaining a conventional non-melting joining method by friction stirring.
[0032]
In the conventional joining method shown in FIG. 2, the first and second members W1, W2 are arranged so as to be sandwiched between the rotary tool 1 and the fixed tool 10 ′, and the rotary tool 1 is placed on the first member W1 on the outermost surface. The procedure of press-fitting by pressurizing while rotating around the axis is the same as in the present invention, but the member structure between the first and second members W1 and W2 that are superimposed is agitated in a non-molten state by frictional heat. Are different in that they are joined.
[0033]
Here, the state of stirring without melting means that the metal structure is softened by frictional heat and stirred at a temperature lower than the lowest melting point of each component or eutectic compound contained in the base material. Means that.
[0034]
And since the conventional joining method stirs without melting, there is a merit of solving problems such as thermal distortion caused by electric resistance welding or the like.
[0035]
On the other hand, the rotational speed and pressure of the rotary tool 1 cannot be increased due to frictional stirring without melting, and the area of the receiving surface 11 ′ that contacts the second member W2 in the fixed tool 10 ′ is the rotational tool. Since the area of the projecting portion 3 projecting from the tip end portion of 1 is large, the applied pressure is dispersed over the entire surface of the receiving surface 11 ′, and the frictional heat due to the rotation of the rotary tool 1 is dissipated over the entire surface of the receiving surface 11 ′. As a result, there is a demerit that it takes time (for example, 2 to 3 seconds) for joining.
[0036]
On the other hand, in the present invention, it is possible to increase the rotational speed and pressure of the rotary tool 1 for frictional stirring in the molten state, and further, the receiving surface 11 of the fixed tool 10 is at least provided on the rotary tool 1. It is formed smaller than the cross-sectional area of the protrusion 3 to suppress heat dissipation 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, 0.3 to 0) .5 seconds).
[0037]
In addition, as shown in FIG. 3, the protrusion 3 of the rotary tool 1 has a total thickness that increases as the number of overlapping members increases. For example, as shown in FIG. 4, when the rotary tool 1 having two protrusions 3 having a length for superposition joining is applied to three superposition joining, if the joining time is shortened, the intermediate member W2 The amount of stirring of the lower member W3 is insufficient and the strength cannot be secured (see FIG. 4A). Conversely, if the joining time is lengthened, the thickness reduction amount of the upper member W1 becomes too large and the upper member W1 and the intermediate member In any case, the tool used when the number of overlapped members is small cannot be used for joining with a large number of sheets.
[0038]
Therefore, in the present invention, as shown in FIGS. 5 and 6, the second and third diameters that are concentric and have a small diameter so as to form at least one step from the tip of the rotary tool 1 toward the protrusion 3. By providing the shoulder portions 4 and 5, the length of the protruding portion 3 remains as it is for two sheets, and three or more sheets or a large total plate thickness can be joined together.
[0039]
Further, considering the pressing state from the fixed tool 10 at the time of joining, when the receiving surface 11 shown in FIG. 7 is flat, the stress concentrates on the corner portion 12 and the fixed tool 10 sinks into the member W. The amount increases. For this reason, in the present invention, as shown in FIG. 8, the receiving surface 11 of the fixed tool 10 is curved and the corners 12 are formed smoothly, thereby reducing stress concentration on the member W and sinking. ing. In addition, by forming the receiving surface 11 in a curved shape, even if the angle of contact with the member W is slightly shifted, it can be configured to make the receiving with a surface instead of a point or a line, thereby suppressing variations in bonding strength, Stable bonding quality can be easily ensured.
[Rotating tool used for joining]
9 and 10 are external views of a rotary tool used for friction stir welding according to an embodiment of the present invention. FIG. 11 is a front view of a fixed tool used for friction stir welding according to an embodiment of the present invention.
[0040]
The rotating tool shown in FIG. 9 is used for joining with the number of overlaps of about 2 and the total thickness being relatively small. The cylindrical first shoulder portion 2 (corresponding to the first tool portion) and this A cylindrical projecting portion 3 (corresponding to a second tool portion) having a smaller diameter (or smaller cross-sectional area) than the first shoulder portion 2 and projecting from the distal end portion 2a of the first shoulder 2 at the same axis. .
[0041]
Further, the rotating tool shown in FIG. 10 is used for joining with three or more overlapping sheets and a large total thickness, and has a cylindrical first shoulder portion 2 and a smaller diameter than the first shoulder portion 2 (or , With a small cross-sectional area), a cylindrical projecting portion 3 projecting from the distal end portion 2a of the first shoulder portion 2 with the same axial center, and a concentric and stepped portion from the first shoulder portion 2 toward the projecting portion 3 Are provided with cylindrical second and third shoulder portions 4 and 5 that gradually become smaller in diameter.
[0042]
In the rotating tool shown in FIG. 9, the diameter φ of the first shoulder portion 2 is set to about 5 to 13 mm, and the diameter φ of the protruding portion 3 is set to about 2 to 5 mm.
[0043]
In the rotating tool shown in FIG. 10, the diameter φ of the first shoulder portion 2 is about 13 to 16 mm, the diameter φ of the second shoulder portion 4 is about 10 to 13 mm, the diameter φ of the third shoulder portion 5 is about 5 to 10 mm, The diameter φ of the protrusion 3 is set to about 2 to 5 mm.
[0044]
In order to further improve the machinability and stirring ability, a spiral or parallel groove may be formed on the outer peripheral surface of the protrusion 3. In the case of a spiral groove, the groove may be formed in the direction in which the member tissue is pushed into the member.
[0045]
  A fixed tool 10 shown in FIG. 11 includes an enlarged diameter portion 13 formed in a tapered shape so that a cross-sectional area increases from the receiving surface 11 toward the counter-rotating tool, and the receiving surface 11 (I portion) is a protruding portion.3Is formed in a curved surface of about R30 to 50 mm so as to be able to absorb the displacement of the pressure application point.
[0046]
As shown in FIG. 10, by configuring the rotary tool, it is possible to perform various superposition number and total plate thickness joining without replacing the tool, and joining that has occurred by conventional tool replacement. Time loss can be reduced. Also, since the types of tools to be used are reduced, costs such as tool purchase / processing costs and maintenance costs can be reduced.
[0047]
As shown in FIG. 11, in the fixed tool 10, the diameter φ of the receiving surface 11 is about 7 to 13 mm, the diameter φ of the large diameter portion of the enlarged diameter portion 13 is about 13 to 16 mm, and the diameter φ of the small diameter portion is From the surface 11 toward the diameter-expanded portion 13, it expands in a tapered shape according to the respective dimensions.
[0048]
FIG. 12 is a front view showing the rotary tool and a mounting bracket for the rotary tool.
[0049]
  As shown in FIG. 12, the anti-projection part of the rotary tool 13A tapered taper hole 6 is formed in the end face on the side, and a non-rotating guide groove 7 is formed around the taper hole 6 at equal intervals (for example, every 90 ° around the axis). Further, the end surface of the mounting bracket 20 on the rotating tool 1 side is formed in a tapered shape, and a detent guide 22 that fits in the detent guide groove 7 is provided around the tapered surface 21.
[0050]
Then, the taper hole 6 and the rotation prevention guide groove 7 of the rotary tool 1 are fitted to the taper surface 21 of the mounting bracket 20 and the rotation prevention guide 22, respectively. Are configured so as not to rotate relative to each other.
[0051]
The mounting bracket 20 is formed so as to have an integral shaft shape with approximately the same diameter φ13 to 16 mm in a state where the rotary tool 1 is fixed, and the length thereof is set to a length suitable for a member to be joined. . A robot mounting portion 23 having a diameter φ of about 10 to 13 mm is extended on the end surface of the mounting bracket 20 on the counter-rotating tool side. The robot mounting portion 23 is attached to a motor shaft of a multi-joint robot (not shown) as a holder. It is rotationally driven together with the rotary tool 1 by being attached via.
[0052]
FIG. 13 is a schematic view of an articulated robot that fixes and drives a rotating tool.
[0053]
As shown in FIG. 13, the articulated robot 30 is connected to a joint 32 provided on a base 31, swings about the y-axis center, and rotates with a joint 33 about the z-axis, The second arm 37 is connected to the first arm 34 via the shaft 35 and swings about the y-axis center, and is rotated about the x-axis center at the joint 36, and the second arm 37 is connected to the second arm 37 via the joint 38. And a third arm 39 that swings about the axis.
[0054]
A joining gun 50 is attached to the tip of the third arm 39. The rotating tool 1 is rotatably attached to the joining gun 50, and the motor 51 that rotationally drives the rotating tool 1 and the fixed tool 10 are attached so as to face the rotating tool 1. The interval between the rotary tool 1 and the fixed tool 10 is variable by an actuator 52, and is configured so that it can be applied to three or more superposition joints by controlling the pressure applied to the members during joining and the number of tool rotations. Yes.
[0055]
The operations of the arms, motors, and actuators of the articulated robot 30 are taught in advance and are controlled by the robot control unit 60 via the power / control cable 61.
[0056]
FIG. 14 is a detailed view of the joining gun shown in FIG.
[0057]
As shown in FIG. 14, in the joining gun 50, the fixing tool 10 is attached to a lower end arm 56 that extends in the lateral direction from the lower end portion of the gun arm 55 via an attachment bracket 57.
[0058]
A drive unit 58 that rotates and drives the rotary tool 1 in the vertical direction is attached to the upper end of the gun arm 55. The drive unit 58 includes a guide table 53 that is guided in the vertical direction by a ball screw mechanism 54 that uses the vertical drive motor 52 as a drive source, and the rotational drive motor 51 is fixed to the guide table 53. The rotary tool 1 is attached to the rotary shaft 51a of the rotary drive motor 51 via a holder or the like, and is disposed so as to face the fixed tool 10.
[0059]
The rotary tool 1 is moved in the vertical direction by the movement of the guide table 53 by the vertical drive motor 52 and the ball screw mechanism 54, and is rotated by the rotary drive motor 51.
[0060]
In the present embodiment, it is possible to prevent a joining failure caused by equipment abnormality from the control parameters of the joining equipment (joining gun, rotary drive motor, vertical drive motor, rotary tool, etc.), Calculate the amount of heat generated from the load applied to the member (pressing force, number of rotations, tool contact diameter, etc.), and join quality during joining based on the relationship between the amount of heat generated and the amount of pushing the rotating tool into the member (thickness reduction amount). In other words, all joints can be inspected nondestructively, and quality assurance can be determined within the production line (inline).
[Joint control]
Next, the joining control method by friction stirring of this embodiment will be described.
[0061]
FIG. 15 is a flowchart for explaining a joining control method by friction stirring according to the present embodiment.
[0062]
As shown in FIG. 15, in step S1, suitable joining is performed from a database in which joining conditions such as the number of rotations of the rotary tool, pressure, and joining time are set in advance by experiments or the like based on the combination of materials to be joined and the plate thickness. Calculate the conditions.
[0063]
In step S3, the rotary tool is started to rotate.
[0064]
In step S5, the process waits for the rotation tool to reach the set number of revolutions. If the rotation tool has been reached, the process proceeds to step S7, where the rotation tool is lowered to start pressurizing the member. The tool rotation speed is calculated from the encoder value of the rotation drive motor. Further, the applied pressure is calculated from the feedback current value of the vertical drive motor. Further, the distance between the tool of the rotating tool and the fixed tool is calculated from the gun arm deflection correction table set in advance by experiments and the encoder value of the vertical drive motor.
[0065]
In step S9, when the rotating tool reaches the set pressure and detects the completion of press-fitting into the member of the protruding portion of the rotating tool from the distance between the tools, the rotating tool rotates with the shoulder portion in contact with the member. Fever.
[0066]
  In step S11, against the member of the protrusion 3PushImpregnationAmountAt the same time, the load applied to the rotating tool is calculated in step S13.
[0067]
  Above rotation toolPushImpregnationAmount, Calculated from the distance between the tools. The load applied to the rotary tool is calculated from the feedback current value of the rotary drive motor.
[0068]
  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 a predetermined reference value is exceeded, the joining condition (pressing force, rotation speed) is corrected or changed to correct the joining failure. Reduce the thickness reduction that causes (decrease in bonding strength). In addition, the rotation tool calculated in step S11Push amountThe bonding conditions (pressing force and rotational speed) are corrected or changed so as to be suitable.
[0069]
In step S17, the joining process of steps S13 to S17 is held under the joining conditions corrected (changed) in step S15 until the joining time set in step S1 is reached, and joining is completed after the joining time has elapsed. .
[0070]
The pressurizing force is controlled by setting in advance a relationship between the pressurizing force at the tool tip and the current value of the vertical drive motor required at that time, and calculating the pressurizing force correction formula using this table. . Then, the feedback current of the vertical drive motor at the time of pressurization is detected, and the applied pressure can be calculated from the feedback current value and the applied pressure correction formula.
[0071]
  Tool tip position of the above rotating toolIsThe figure16As shown in,Lack ofIt is calculated by comparing the encoder value of the vertical drive motor at the reference position when the loss is confirmed with the encoder value of the motor at the position where the current rotary tool is located. The distance between tools is16As shown in Fig. 4, the relationship between the applied pressure and the deflection amount of the gun arm is set in advance in a table, the deflection correction formula is obtained from this table, and the applied pressure generated during joining is determined by the feedback current value of the vertical drive motor and the deflection correction formula. The amount of deflection of the gun arm when the pressure is applied with this applied pressure is calculated from the deflection correction formula. The inter-tool distance is calculated from the relationship between the gun arm deflection amount and the tool tip position of the rotary tool.
[0072]
In the above control, the joining time may be changed according to the load applied to the rotary tool.
[0073]
  According to the above-described embodiment, by detecting the joining state from the tool tip position and the load, and controlling the joining conditions (pressing force, rotation speed, joining time) suitable for this joining state, By generating plastic flow suitable for the plate thickness, it is possible to reduce bonding defects and secure stable bonding quality.
[Quality Assurance Method]
  Next, a quality assurance method in the joining method by friction stirrer of the present embodimentInexplain about.
[0074]
FIG. 16 is a flowchart for explaining a quality assurance method in the friction stir welding method of the present embodiment.
[0075]
  As shown in FIG. 16, in step S21, before entering the actual joining, the protruding portion of the rotary tool 1 without any members interposed therebetween.3The position where the abuts against the member is calculated.
[0076]
  In step S23, the protruding portion of the rotary tool 1 is compared with the contact position calculated in step S21 and a predetermined reference position.3Check for missing parts due to wear.
[0077]
The reference position is a position when a new rotating tool 1 having no defect is used and the rotating tool 1 comes into contact with the fixed tool 10 and reaches a predetermined pressure. Then, when the contact position exceeds the reference position by a predetermined amount, it is determined that there is a defect.
[0078]
  In step S23, the protruding portion3Is determined to be missing, the process proceeds to step S25, and the subsequent robot operation is stopped as an abnormality.
[0079]
If it is determined that there is no defect in the defect confirmation in step S23, the program is activated in step S27 and the joining process is started.
[0080]
  Step S31Rotation toolofStart rotating.
[0081]
If the rotation number of the rotary tool has reached the set value from the encoder value of the rotary drive motor in step S33, the process proceeds to step S37, where the rotary tool 1 is lowered to start pressurizing the member. If the set number of rotations is not reached even after a predetermined time has elapsed, an abnormal operation is stopped in step S35 and the subsequent robot operation is stopped.
[0082]
  When the rotating tool reaches the set pressure in step S39, the tool rotates with the shoulder portion of the rotating tool in contact with the member and starts to generate heat. In step S43, the tool tip position relative to the member of the protruding portion 3 is started.PlaceIn addition to the calculation, a load applied to the rotating tool is calculated in step S45. If the set pressure is not reached even after a predetermined time has elapsed, an abnormal robot is stopped in step S41 and the subsequent robot operation is stopped.
[0083]
The pressurizing force is controlled by setting in advance a relationship between the pressurizing force at the tool tip and the current value of the vertical drive motor required at that time, and calculating the pressurizing force correction formula using this table. . Then, the feedback current of the vertical drive motor during pressurization is detected, and the applied pressure can be calculated from the feedback current value and the applied pressure correction formula.
[0084]
  Tool tip position of the above rotating toolIsThe figure16As shown in FIG. 4, the encoder value of the vertical drive motor at the reference position at the time of confirmation of the deficiency is compared with the encoder value of the motor at the position where the current rotary tool is located. The distance between tools is16As shown in Fig. 2, the relationship between the applied pressure and the deflection amount of the gun arm is set in a table in advance, and a deflection correction formula is obtained from this table. The amount of deflection of the gun arm when the pressure is applied with this applied pressure is calculated from the deflection correction formula. The inter-tool distance is calculated from the relationship between the gun arm deflection amount and the tool tip position of the rotary tool.
[0085]
  For the load applied to the rotary tool, a reference current for each rotation speed is set in advance in a table from the relationship between the feedback current value of the rotation drive motor in the no-load state and the rotation speed detected by the encoder of the rotation drive motor. The reference current calculation formula is obtained from this table, and is calculated from the following relational expression 1 of the reference current obtained from the reference current calculation formula and the feedback current value of the rotary drive motor at the time of joining.
(Formula 1)
  Load at joining = Feedback current value of rotary drive motor at joining-Reference current
  In step S47,The amount of reduction in the plate thickness of the member due to the pressure is calculated.
[0086]
In step S49, the amount of heat generated by friction agitation is calculated from the load or pressure, tool rotation speed, member surface resistance (dynamic friction coefficient), and tool contact diameter.
[0087]
In step S51, the bonding quality is determined while monitoring the plate thickness reduction amount and the heat generation amount. If it is determined that the quality cannot be guaranteed when the bonding is completed, the operator is warned of the bonding failure and the correction is performed. The plate thickness reduction amount is a factor that determines the magnitude of the bonding strength. This is because the thickness of the remaining plate after joining greatly affects the joining strength.
[0088]
  The above plate thickness reduction amount is the distance between tools from the total plate thickness.And the protrusion amount of the protrusion 3The value obtained by subtracting is the total plate thickness reduction amount, and the plate thickness reduction amount of the upper member is obtained by multiplying this total plate thickness reduction amount by the plate thickness reduction ratio (plate thickness reduction amount of the upper member / total plate thickness reduction amount). calculate. Further, the plate thickness reduction amount of the lower member is calculated by subtracting the plate thickness reduction amount of the upper member from the total plate thickness reduction amount (see the following relational expressions 2 to 4). The plate thickness reduction ratio is set in advance by an experiment or the like.
(Formula 2)
  Total plate thickness reduction = Total plate thickness-Distance between tools-Projection amount of the protrusion 3
(Formula 3)
  Plate thickness reduction of upper member = Total plate thickness reduction x Plate thickness reduction ratio (Upper plate thickness reduction / Total plate thickness reduction)
(Formula 4)
  Lower member thickness reduction = Total thickness reduction-Upper member thickness reduction
  FIG. 18 shows the relationship between the applied pressure and the bonding strength. When the bonding strength exceeds the lower limit value in the bonding conditions A, B, and C, it is determined that the quality can be guaranteed, and when the bonding strength is lower, the quality is not guaranteed.
[Joint quality judgment method]
  Next, the joining quality determination method in step S51 will be described.
[0089]
FIG. 17 is a flowchart for explaining a quality assurance method in the friction stir welding method of the present embodiment.
[0090]
As shown in FIG. 17, in step S55, the joint area is calculated by substituting the calorific value calculated in step S49 into a formula for calculating the calorific value and the joint area (or diameter, etc.) obtained in advance by experiments or the like. To do. At the same time, in step S53, it is determined whether the thickness reduction amount calculated in step S47 is within a preset reference value. If it is within the reference value, the strength of the joint area is determined in step S57, If the reference value is exceeded, it is determined that it is difficult to ensure the bonding strength, and it is determined that the quality cannot be guaranteed.
[0091]
In the strength determination 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 (see FIG. 18) stored in advance. If it exceeds the reference value, it is determined that it is difficult to ensure the bonding strength, and it is determined that the quality cannot be guaranteed.
[0092]
As can be seen from FIG. 18, the bonding strength decreases from a certain point P when the applied pressure is increased. This is because the plate thickness reduction amount increases and affects the bonding strength, and the bonding conditions (pressing force and rotational speed) are determined with the point P at which the bonding strength decreases as a reference value.
[0093]
  According to the above-described embodiment, it is possible to detect a joining failure that occurs due to equipment abnormality from the control parameters of the joining equipment (joining gun, rotary drive motor, vertical drive motor, rotary tool, etc.). Also, the heat generation amount is calculated from the dynamic friction coefficient of the members to be joined and the load applied to the member (pressing force, rotation speed, tool contact diameter, etc.), and this heat generation amount and the amount of pushing of the rotary tool into the member (plate thickness reduction amount) By determining the bonding quality during bonding based on the relationship, all the bondings can be inspected nondestructively, and quality assurance can be determined within the production line (in-line).
[0095]
A computer program for executing the joining control method, the joining guarantee method, and the joining quality judgment method corresponding to the flowcharts shown in FIGS. 15 to 17 is supplied to a computer, and a storage medium storing the program code is supplied to the computer. The computer may read 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 stirrer 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 view showing a state of joining with a rotary tool having three protrusions having a length for overlapping joining.
FIG. 4 is a diagram showing a state of joining in a case where three overlapping joinings are performed by changing the time with a rotary tool having a protruding portion having a length for two overlapping joinings.
FIG. 5 is a view showing a state of joining when two sheets are superposed and joined by the rotary tool according to the embodiment of the present invention.
FIG. 6 is a view showing a state of joining in a case where three sheets are superposed and joined with the rotary tool according to the embodiment of the present invention.
FIG. 7 is a diagram illustrating an influence on a member due to pressurization 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 fixed tool having a curved receiving surface.
FIG. 9 is an external view of a rotary tool used for friction stir welding according to an embodiment of the present invention.
FIG. 10 is an external view of a rotary tool used for friction stir welding according to an embodiment of the present invention.
FIG. 11 is a front view of a fixed tool used for friction stir welding according to an embodiment of the present invention.
FIG. 12 is a front view showing a rotary tool and a mounting bracket for the rotary tool.
FIG. 13 is a schematic view of an articulated robot that fixes and drives a rotary tool.
14 is a detailed view of the joining gun shown in FIG.
FIG. 15 is a flowchart for explaining a joining control method by friction stirring according to the embodiment.
FIG. 16 is a flowchart for explaining a quality assurance method in the friction stir welding method of the present embodiment.
FIG. 17 is a flowchart for explaining a quality assurance method in the friction stir welding method of the present embodiment.
FIG. 18 is a diagram showing the relationship between the applied pressure and the bonding strength.
FIG. 19 is a diagram for explaining a relationship among a tool tip position, a tool-to-tool distance, and a gun arm deflection amount.
[Explanation of symbols]
1 Rotating tool
3 Protrusion
10 Fixing tool
30 Articulated robot
W1-W3 members

Claims (7)

At least two members are overlapped, and a rotary tool having a shoulder portion and a protruding portion protruding from the shoulder portion is pressed and pressed into one member while rotating around its axis, and stirred by friction. A process management method for locally joining members together,
And detecting the position of the tip of the projecting portion of the front Symbol rotating tool,
Based on the tip position , a thickness reduction amount of the joining portion of the one member generated by the shoulder portion being pushed into the one member is calculated, and joining is performed based on the calculated thickness reduction amount. And a step of determining whether the strength is good or not. At least two members are overlapped, and a rotary tool having a shoulder portion and a protruding portion protruding from the shoulder portion is pressed and pressed into one member while rotating around its axis, and stirred by friction. A process management method for locally joining members together,
And the dynamic coefficient of friction between the rotating tool and the one member, a step of calculating the calorific value based on the load of the rotary tool relative to the one member at the time of joining,
And detecting the position of the tip of the projecting portion of the front Symbol rotating tool,
Based on the formula representing the relationship between the calorific value obtained in advance and the joint area between the members, the joint area is calculated based on the calorific value, and the shoulder portion is the one member based on the tip position. The thickness reduction amount of the joint portion of the one member generated by being pushed into is calculated, and it is determined whether the plate thickness reduction amount is within a preset reference value. And a step of determining whether the bonding strength is good or not based on the bonding area. The processing management using friction agitation according to claim 1 or 2, wherein the tip position is calculated based on an encoder output of a motor for raising and lowering the rotary tool relative to the one member. Method. The calculation of the thickness reduction amount of the joint portion of the one member is performed by using the tip of the projecting portion of the rotating tool pushed into the one member and the other member at the time of joining which is disposed facing the rotating tool. The total plate thickness reduction amount is calculated based on a distance from the fixed tool to be received, and is calculated by multiplying the total plate thickness reduction amount by the plate thickness reduction ratio of the one member. A process management method using friction stirring according to 1 or 2. Superimposing at least two members, pushing pressurizes the rotary tool on one of the members while rotating about its axis and a projection projecting from the shoulder portion and said shoulder portion at its distal end, stirred by friction A processing management device for locally joining members together,
A detecting means that detect the position of the tip of the projecting portion of the front Symbol rotating tool,
Based on the tip position , a thickness reduction amount of the joining portion of the one member generated by the shoulder portion being pushed into the one member is calculated, and joining is performed based on the calculated thickness reduction amount. A processing management apparatus using friction stirrer, comprising: a joining state detecting means for judging whether the strength is good or bad. Superimposing at least two members, pushing pressurizes the rotary tool on one of the members while rotating about its axis and a projection projecting from the shoulder portion and said shoulder portion at its distal end, stirred by friction A processing management device for locally joining members together,
A calorific value calculation means for calculating a calorific value based on a dynamic friction coefficient between the one member and the rotary tool and a load of the rotary tool on the one member at the time of joining;
A detecting means that detect the position of the tip of the projecting portion of the front Symbol rotating tool,
Based on the formula representing the relationship between the calorific value obtained in advance and the joint area between the members, the joint area is calculated based on the calorific value, and the shoulder portion is the one member based on the tip position. The thickness reduction amount of the joint portion of the one member generated by being pushed into is calculated, and it is determined whether the plate thickness reduction amount is within a preset reference value. A processing management apparatus using friction stirrer, comprising: a joining state detecting means for judging whether the joining strength is good or not based on the joint area. Before dangerous detecting means is friction stir according to claim 5 or 6, characterized in that for calculating the tip position based on the rotation tool to the encoder output of the motor for raising and lowering relative to the one member said Process management device using

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