JP2019171466A - Tool for friction stir welding and friction stir welding device - Google Patents

Abstract

To prevent, in a tool for friction stir welding in which a pin and a shoulder are separate from each other, a tool service life from deteriorating even if material residue enters between the pin and the shoulder.SOLUTION: A tool for friction stir welding according to the present invention comprises a stirring pin having a rotation axis, and a housing having a first surface. The housing includes an accommodation hole which accommodates the stirring pin so that the stirring pin is capable of rotating about the rotation axis, and which opens in the first surface. The stirring pin includes, on one end along the rotation axis thereof, a stirring part which protrudes from the first surface in a state that the stirring pin is accommodated in the accommodation hole, and which is inserted into a workpiece. The housing is formed with a discharge hole which communicates with the accommodation hole and the outside of the housing. The accommodation hole includes a first accommodation hole and a second accommodation hole, which are connected to each other along the rotation axis. The first accommodation hole opens in the first surface, and the second accommodation hole is larger in hole diameter than the first accommodation hole. The discharge hole is formed at a position including a boundary between the first accommodation hole and the second accommodation hole.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a friction stir welding tool and a friction stir welding apparatus to which the tool is applied.

  A rotating tool consisting of a pin and a shoulder, which are configured separately, is attached to the rotating head, inserted into the workpiece while rotating the pin relative to the shoulder, and the workpiece is heated by frictional heat between the workpiece and the rotating tool. A so-called friction stir welding technique is known in which joining is performed by generating plastic flow. According to such friction stir welding, by joining the workpieces without melting them, excessive heat input to the workpieces can be reduced, so that deterioration of the workpiece material and deformation after joining can be suppressed.

  As one of such friction stir welding techniques, for example, a friction stir welding apparatus disclosed in Patent Document 1 and Patent Document 2 is known. Such a joining apparatus is applied to continuous joining of two members to a butting portion, spot joining (spot joining) to an overlapping portion, or the like.

Special table 2009-537325 gazette JP 2007-313520 A

  In the joining apparatus disclosed in Patent Literature 1 and Patent Literature 2, frictional heat is generated between the material residue and the pin that has entered between the pin and the shoulder member, the pin is excessively heated, and the strength decreases. Or it will cause damage of a pin, and will contribute to the fall of tool life.

  The present invention has been made in view of the situation as described above, and its purpose is that when the pin and the shoulder are configured separately, a part of the workpiece has entered from the gap between the pin and the shoulder. Even if it is a case, it is providing the tool for friction stir welding which can suppress the intensity | strength fall of a pin, a breakage, etc., and a friction stir welding apparatus using the same.

  According to the first aspect of the present invention, the friction stir welding tool includes a stirring pin having a rotation shaft and a housing having a first surface, and the housing relatively rotates the stirring pin. The first surface includes an accommodation hole that is rotatably accommodated about an axis and opens in the first surface, and the stirring pin is accommodated in the accommodation hole at one end along the rotation axis. The housing includes a stirring portion that is inserted into the workpiece, and the housing is formed with a discharge hole that communicates with the housing hole and the outside of the housing, and the housing hole extends along the rotation axis. The first receiving hole includes a first receiving hole and a second receiving hole that are connected to each other, the first receiving hole opens in the first surface, and the second receiving hole is formed from the first receiving hole. The hole diameter is large, and the discharge hole has the first accommodation hole and the second accommodation hole. Characterized in that it is formed at a position including the boundary between.

  According to the second aspect of the present invention, a friction stir welding apparatus includes a headstock including a rotation main shaft, the friction stir welding tool attached to the head stock, a processing table for holding a workpiece, and a main shaft. And a numerical controller for controlling relative movement of the table and the processing table.

  According to this invention, in the housing of the friction stir welding tool, by providing the accommodation hole that accommodates the agitation pin and the discharge hole that communicates the outside of the housing, the workpiece that has entered from the clearance between the agitation pin and the accommodation hole of the housing Can be discharged from the discharge hole, so that a reduction in strength or breakage of the stirring pin can be suppressed.

It is a fragmentary sectional view which shows the outline | summary of the friction stir welding apparatus to which the tool for friction stir welding by Example 1 of this invention is applied. It is sectional drawing which shows the specific characteristic in the principal part of the tool for friction stir welding by Example 1 of this invention, Comprising: The outline | summary of the tool tip at the time of use is shown. It is sectional drawing which shows the specific characteristic in the principal part of the tool for friction stir welding by Example 1 of this invention, Comprising: The outline | summary of the front-end | tip vicinity of a housing is shown. It is sectional drawing which shows the specific characteristic in the principal part of the tool for friction stir welding by Example 1 of this invention, Comprising: The outline | summary of the stirring pin accommodated in a housing is shown. It is sectional drawing which shows the outline | summary when the butt | matching part of two metal plates is friction stir welded using the tool for friction stir welding by Example 1 of this invention. It is sectional drawing which shows the specific characteristic in the principal part of the tool for friction stir welding by Example 2 of this invention, Comprising: The outline | summary of the tool front end at the time of use is shown. It is sectional drawing which shows the specific characteristic in the principal part of the tool for friction stir welding by Example 2 of this invention, Comprising: The outline | summary of the attachment structure of a housing main body and a shoulder is shown. It is a side view for demonstrating the specific structure of the shoulder shown to FIG. 4B. It is a bottom view for demonstrating the specific structure of the shoulder shown to FIG. 4B. It is a top view for demonstrating the specific structure of the shoulder shown to FIG. 4B. It is sectional drawing which shows the specific characteristic in the principal part of the tool for friction stir welding by Example 3 of this invention, Comprising: The outline | summary of the tool front-end | tip at the time of use is shown. It is sectional drawing which shows the specific characteristic in the principal part of the tool for friction stir welding by Example 3 of this invention, Comprising: The outline | summary of the attachment structure of a housing main body and a shoulder is shown. It is sectional drawing which shows the specific characteristic in the principal part of the tool for friction stir welding by Example 4 of this invention, Comprising: The outline | summary of the tool front end at the time of use is shown. It is sectional drawing which shows the specific characteristic in the principal part of the tool for friction stir welding by Example 4 of this invention, Comprising: The outline | summary of the attachment structure of a housing main body and a shoulder is shown. It is sectional drawing which shows the outline | summary of the tool front end at the time of use of the tool for friction stir welding by Example 5 of this invention. It is a side view for demonstrating the specific structure of the shoulder applied to the tool for friction stir welding by Example 6 of this invention. It is a bottom view for demonstrating the specific structure of the shoulder applied to the tool for friction stir welding by Example 6 of this invention. It is a top view for demonstrating the specific structure of the shoulder applied to the tool for friction stir welding by Example 6 of this invention.

  As one of the friction stir welding techniques, a friction stir welding tool in which a pin and a shoulder are configured separately is attached to a rotary head, and the workpiece is rotated while the pin is rotated with respect to the shoulder while the shoulder is in contact with the workpiece. There is known a joining apparatus that is inserted into the inside of the machine and performs friction stir welding (see, for example, Patent Document 1). Such a joining apparatus has an advantage that the frictional heat generation necessary for joining can be satisfied only by rotation of the pin, and continuous joining to the butt portion of two members or point joining (spot joining) to the overlapping portion. Etc.

  In such a joining apparatus, since the friction stir welding tool is configured separately from the pin and the housing including the shoulder, there is a predetermined clearance (gap) between the pin and the housing. Inevitable. For this reason, a part of the material of the workpiece plastically flowed during the friction stir welding enters the inside of the tool through the clearance.

  In such a case, if the workpiece cools after joining, part of the workpiece that has entered the tool will also cool and solidify, causing the workpiece to adhere between the pin and the housing, making it difficult to use the tool repeatedly. There was. In addition, since the invaded workpiece remains inside the tool without being discharged to the outside, after a certain workpiece has entered, a part of the plastic flowed workpiece leaks from between the shoulder and the workpiece and adheres to the upper surface of the workpiece. Reducing the quality of the joint surface.

  In order to eliminate such a phenomenon, in a friction stir spot welding apparatus using a so-called double-acting rotary tool in which a probe (pin) and a shoulder member are separately formed (see, for example, Patent Document 2), A plurality of discharge holes are formed on the side wall, a plurality of protrusions are also formed on the outer periphery of the probe, and the material residue that has entered between the probe and the shoulder member at the time of friction stir spot bonding is finely divided by the protrusions, An improvement has been made to discharge from the discharge hole. As a result, in the point joining, it is possible to efficiently discharge the material residue that has entered the inside of the tool to the outside and avoid adhesion between the probe and the shoulder member.

  However, in the case of a friction stir welding apparatus that continuously welds along the butt part of two workpieces, from the beginning to the end of joining, that is, from the time when the tip of the pin is pushed into the butt part until it is pulled out. In addition, since a part of the workpiece continuously enters the inside of the housing from the gap between the pin and the shoulder, a part of a large amount of the workpiece stays inside the housing. At this time, since the pins constituting the tool are always rotating during continuous friction stir welding, when a part of the work staying in the housing comes into contact with the pins, the rotating pin and the work Friction heat is generated between the part and the pin is heated excessively, resulting in a decrease in strength, or eventually causing a breakage of the pin.

  On the other hand, in the above-mentioned friction stir spot welding device, it is possible to discharge the material residue that has entered between the probe and the shoulder member to the outside, but the spot welding is basically performed by the tool along the joint surface of the workpiece. Since there is no movement, and the joining time per one part of the joining is very short, the amount of material waste that penetrates into the tool each time does not increase so much. For this reason, in the friction stir shop joining apparatus, the invaded material residue is divided by the projections formed on the probe, so that it can be discharged to the outside as a small piece.

  However, a tool having a discharge hole as described above forms a space in which the material residue is intentionally retained between the probe and the shoulder member, and the material residue is finely divided by the projection formed on the probe in the space. Therefore, even if continuous friction stir welding is performed using such a tool, the material residue that continuously enters and the probe come into contact with each other to generate frictional heat. There is no change, and due to the frictional heat, there is an inevitable problem that the tool life is unavoidable due to a decrease in the strength or breakage of the probe.

  In view of this, the friction stir welding tool in the embodiment includes a housing provided with a receiving hole that houses the stirring pin and a discharge hole that communicates the outside of the housing. By providing such a discharge hole, the invading material residue can be continuously discharged, so that a decrease in strength or breakage of the probe can be suppressed, and a decrease in tool life can be avoided. In addition, the description of the matter recognized by the inventor is described as a reference in order to deepen the understanding of the friction stir welding tool in the embodiment, and does not indicate a known technique.

<Example 1>
1 is a partial cross-sectional view showing an outline of a friction stir welding apparatus to which a friction stir welding tool according to a first embodiment of the present invention is applied. As shown in FIG. 1, the friction stir welding apparatus 1 to which the friction stir welding tool 100 according to the first embodiment of the present invention is applied includes a main body unit 10, a work transport unit 20, and a control unit 30.

  The main body 10 of the friction stir welding apparatus 1 includes a headstock 12 and a headstock feed device 18. The head stock 12 includes a main spindle frame 14 and a rotary main spindle 16 included so as to rotate relative to the main spindle frame 14. The spindle feeder 18 moves the spindle stock 12 in the three-axis directions of XYZ. A housing 110 of a friction stir welding tool 100 described later is installed at the lower end of the spindle frame 14.

  On the other hand, a stirring pin 120 of the friction stir welding tool 100 is connected to the rotary main shaft 16. Thereby, in the friction stir welding tool 100 according to the first embodiment of the present invention, the stirring pin 120 rotates relative to the housing 110.

  The workpiece conveyance unit 20 includes a machining table 22 on which the workpiece W is placed and supported, and a machining table feeding device 24 that moves the machining table 22 in the XY directions. The processing table 22 is provided with a support mechanism (not shown) such as a clamp for fixing and supporting the workpiece W to be joined on the upper surface thereof, and is driven with respect to the friction stir welding tool 100 by driving the processing table feeding device 24. The workpiece W is moved relatively.

  For example, the control unit 30 allows the operator to control the numerical control device 32 that controls the movement of the entire friction stir welding apparatus 1 including the headstock 12, the processing table 22, and the like, and the processing conditions in the processing control that the numerical control device 32 executes. An interface 34 for inputting and a memory 36 for storing data 36a such as various machining programs and machining conditions are provided. The numerical control device 32 includes a rotation control unit 32 a that outputs a rotation command signal for controlling the rotation of the friction stir welding tool 100 to the rotation drive unit 12 a built in the head stock 12 of the main body 10, and the head stock feed device 18. And a feed axis controller 32b that outputs a feed command signal for controlling the movement of the headstock 12 to a feed axis drive unit 18a built in the machine. Thereby, the relative movement of the headstock 12 and the machining table 22, the rotational speed of the friction stir welding tool 100 during joining, the tool insertion depth into the workpiece W, and the like are controlled.

  The friction stir welding tool 100 according to the first embodiment of the present invention includes a housing 110 attached to the lower end of the spindle frame 14 and a stirring pin 120 attached to the rotary spindle 16. The housing 110 is configured by a housing body 112 having a first surface (shoulder surface) 114a that is formed at the upper end with a mounting portion 116 that is installed on the spindle frame 14 and that contacts the work W in a non-rotating state. ing. On the other hand, the agitation pin 120 includes a pin holder 122 attached to the rotation main shaft 16 and a pin body 124 detachably attached to the pin holder 122, and extends along the rotation axis C.

  2A to 2C are cross-sectional views showing specific features of the main part of the friction stir welding tool according to the first embodiment of the present invention. FIG. 2A shows an outline of the tool tip in use, and FIG. Shows an outline of the vicinity of the tip of the housing, and FIG. 2C shows an outline of the stirring pin accommodated in the housing. As shown in FIG. 2A, the friction stir welding tool 100 according to the first embodiment of the present invention is accommodated from the upper end side attached to the spindle frame 14 to the lower end side where the first surface 114a is formed inside the housing 110. A hole SH is formed.

  The accommodation hole SH accommodates the stirring pin 120 so as to be relatively rotatable around the rotation axis C with respect to the housing 110, and opens in the first surface 114a. Furthermore, the stirring pin 120 includes, at one end along the rotation axis C, a stirring portion 124a that protrudes from the first surface 114a while being accommodated in the accommodation hole SH and is inserted into the workpiece. Further, the housing 110 is formed with a discharge hole 118 that allows the accommodation hole SH to communicate with the outside of the housing 110.

  As shown in FIG. 2B, the housing 110 has a first surface 114 a that contacts the upper surface of the workpiece W at the lower end of the housing body 112. The housing hole SH of the housing body 112 includes a first housing hole H1 and a second housing hole H2 that are connected to each other. The 1st accommodation hole H1 is located in the 1st surface 114a side with respect to the 2nd accommodation hole H2, and opens to the 1st surface 114a. The second accommodation hole H2 is located on the rotation main shaft 16 side with respect to the first accommodation hole H1.

  Here, it is preferable that the first surface 114 a contacts the workpiece W with an area smaller than the projected area of the housing 110. For this reason, a reduced diameter portion 113 having a reduced outer diameter is formed as an example at the lower end of the housing main body 112, and a protruding portion 114 that tapers from the lower portion toward the tip is formed. The first surface 114a located in the portion functions as a shoulder surface that comes into contact with the workpiece when performing friction stir welding.

  Further, the protruding portion 114 is formed with a first accommodation hole H1 connected to the second accommodation hole H2, and a part of the pin main body 124 of the stirring pin 120 is accommodated. Here, as an example, the first accommodation hole H1 and the second accommodation hole H2 are set so that the hole diameter is larger than the outer diameter of the pin main body 124 of the agitating pin 120 described later, and the second accommodation hole H2. Is set so that the hole diameter is larger than that of the first accommodation hole H1.

  On the other hand, as a feature of the friction stir welding tool 100 according to the first embodiment of the present invention, the housing main body 112 is formed with a discharge hole 118 that communicates from the accommodation hole SH to the outside of the housing main body 112. Here, the discharge hole 118 is preferably formed at a position including the boundary B between the first accommodation hole H1 and the second accommodation hole H2. Further, the discharge hole 118 may be formed by additionally processing a hole penetrating inward by drilling or milling.

  As shown in FIG. 2C, the agitation pin 120 includes a pin body 124 having an agitation part 124a at one end and a pin holder 122, which are separated from each other along the rotation axis C with respect to the agitation part 124a. On the other side, it is configured to be attached to the pin holder 122 and is rotatably accommodated in the accommodation hole SH of the housing body 112 as shown in FIG. 2A. The pin main body 124 performs friction stir welding by rotating around the rotation axis C and moving relative to the workpiece W in a state where the stirring portion 124a at one end thereof is pushed into the workpiece W. At this time, the housing 110 is in non-rotating contact with the workpiece W, and the stirring pin 120 is structured to rotate with respect to the housing 110, so that the space between the inner surface of the first accommodation hole H1 and the outer surface of the pin body 124 is between. A gap (clearance) G having a predetermined interval is formed.

  FIG. 3 is a cross-sectional view showing an outline when the abutting portions of two metal plates are friction stir welded using the friction stir welding tool according to Example 1 of the present invention. As shown in FIG. 3, when the friction stir welding is performed by abutting the end surfaces of the workpieces W <b> 1 and W <b> 2 made of two metal plates fixedly supported on the processing table 22, the stirring pin 120 of the friction stir welding tool 100 is used. The agitating portion 124a of the pin main body 124 is rotated around the rotation axis C, for example, in the direction indicated by the rotation direction R in the drawing, and the first portion of the housing main body 112 is placed on the abutting portion of the two workpieces W1 and W2. Push until the surface 114a contacts. If the tool or the workpiece is relatively moved along the direction orthogonal to the upper surface of the drawing while maintaining this state, that is, the surface of the abutting portion of the workpieces W1 and W2, the friction stir welding is performed on the abutting portion after the movement. A joined portion J is formed.

  At this time, the first surface 114a of the housing body 112 contacts the upper surface of the abutting portion of the workpieces W1 and W2 as a shoulder surface, and the agitating portion 124a of the pin body 124 is inserted into the abutting portion. For this reason, of the material softened by frictional heat during the friction stir welding, the surplus corresponding to the volume of the portion of the housing body 112 submerged in the workpieces W1 and W2 or the portion inserted into the butt portion of the stirring portion 124a The metal M tends to plastically flow to the upper surface side of the butt portion. Here, when a joining tool in which a general pin and a shoulder are integrated is used, the surplus metal M overflows to the outside of the shoulder and becomes a “burr” on the surface of the joint.

  On the other hand, in the friction stir welding tool 100 according to the present invention in which the pin and the shoulder are separately formed, a part of the surplus metal M may become “burrs” as in the above case. Most of them enter the second accommodation hole H2 of the accommodation hole SH formed in the housing body 112 through the gap G between the first accommodation hole H1 and the pin body 124 shown in FIG. 2A. . The intrusion amount of the surplus metal M passing through the gap G is adjusted by using a housing having a different hole diameter of the first accommodation hole H1 with respect to the shape of the pin body 124 determined by the joining conditions.

  Here, in the friction stir welding tool 100 according to the first embodiment of the present invention, by forming the discharge hole 118 that communicates the second accommodation hole H2 in the accommodation hole SH of the housing main body 112 with the outside, the above-mentioned is described. As described above, the surplus metal M entering the second accommodation hole H2 is discharged to the outside of the housing body 112. Thereby, even if the surplus metal M which is a part of the workpieces W1 and W2 constantly enters the housing hole SH of the housing 110 of the friction stir welding tool 100 during continuous friction stir welding. Since the surplus metal M does not stay in the accommodation hole SH (particularly the second accommodation hole H2), it is possible to suppress frictional heat generation between the pin body 124 of the agitating pin 120 and the surplus metal M. it can.

  Furthermore, by setting the hole diameter of the second housing hole H2 larger than the hole diameter of the first housing hole H1, the surplus metal M that has entered the housing hole SH is caused by the expansion of the hole diameter of the housing hole SH. Due to the flow away from the rotation axis C and the centrifugal force generated by the rotating operation of the stirring pin 120 during joining, it becomes easy to be discharged to the outside. Here, by forming the discharge hole 118 at a position including the boundary B between the first storage hole H1 and the second storage hole H2, surplus metal M stays in the second storage hole H2 and the discharge hole 118. Without being discharged continuously and smoothly to the outside of the housing body 112.

  Further, the surplus metal M is discharged to the outside as burrs in a state of being gradually cooled and solidified while passing through the discharge hole 118, and therefore does not adhere to the workpiece M and reduce the quality of the joint surface. Further, in order to discharge the surplus metal M more continuously and smoothly, the discharge hole 118 is formed in the accommodation hole SH along the flow generated by the rotation of the stirring pin 120 by the plastically flowing surplus metal M which is a part of the workpiece W. It may be formed to be discharged from the housing 110 to the outside.

  In the housing main body 112, for example, the first surface 114a, the inner surface of the first housing hole H1, the inner surface of the second housing hole H2 in the housing hole SH, the pin body 124, and the like are compatible with the material constituting the workpiece W. It is good to form the film (not shown) which consists of a raw material with low property. Thereby, adhesion with the housing 110 and the stirring pin 120 of the surplus metal M is reduced.

  Further, as shown in FIG. 3, for example, a gas flow supply mechanism (not shown) that supplies a gas flow F to the accommodation hole SH of the housing 110 is further provided on the spindle frame 14 of the headstock 12 to which the housing 110 is attached. You may comprise. As a result, the housing 110 and the agitation pin 120 being joined are cooled, and the surplus metal M that enters the accommodation hole SH is also cooled to facilitate discharge to the outside.

  With this configuration, the friction stir welding tool 100 according to the first embodiment of the present invention projects the pin body 124 that rotates relative to the housing body from the first housing hole H1 of the housing body 112 including the first surface 114a. In the separate tool inserted into the workpiece W, the housing body 112 is provided with the discharge hole 118 that allows the housing hole SH to communicate with the outside, so that the gap G between the first housing hole H1 and the pin body 124 is removed. Even if the surplus metal M that is a part of the workpiece W enters, it can be efficiently discharged to the outside. Thereby, since the pin main body 124 and the surplus metal M do not excessively generate heat by friction in the accommodation hole SH formed in the housing 110, a decrease in strength, breakage, or the like of the pin main body 124 can be suppressed as a result. .

  In addition, since the agitation pin 120 is composed of the pin body 124 and the pin holder 122 separately, only the pin body 124 having the agitation portion 124a that always contacts the workpiece W during the friction agitation welding is replaced as a consumable item. By doing so, breakage of the stirring pin 120 itself can be suppressed. Furthermore, since only the pin body 124 can be replaced as a consumable item, the running cost as a friction stir welding tool can be reduced.

<Example 2>
Next, the outline of the friction stir welding tool according to Example 2 of the present invention will be described with reference to FIGS. 4 and 5. In the following description, the configuration of the friction stir welding apparatus to which the friction stir welding tool according to the second embodiment is applied is the same as that of the first embodiment except for the friction stir welding tool including the detachable shoulder. The re-explanation here is omitted.

  4A and 4B are cross-sectional views showing specific features of the main part of the friction stir welding tool according to the second embodiment of the present invention. FIG. 4A shows an outline of the tool tip in use, and FIG. Shows the outline of the mounting structure of the housing body and the shoulder. As shown in FIG. 4A, the friction stir welding tool 200 according to the second embodiment of the present invention includes a housing 210 installed on the spindle frame 14 shown in FIG. 1 and a stirring pin 220 connected to the rotary spindle 16. Composed. The housing 210 is configured separately from the housing main body 212 and a shoulder 230 that is detachably attached to the lower end of the housing main body 212. With the shoulder 230 attached to the housing main body 212, the housing 210 is disposed inside the housing 210. The housing hole SH is formed, and the stirring pin 220 is rotatably accommodated. The stirring pin 220 includes a pin body 224 that is detachably attached and extends along the rotation axis C.

  As shown in FIG. 4B, the housing main body 212 of the housing 210 is formed with a holding portion 217 that holds a shoulder 230 described later, while the lower end thereof is opened. The holding portion 217 of the housing main body 212 includes a holding surface 217 a that holds the held surface 232 a of the shoulder 230, and a contact surface 217 b that contacts the positioning surface 232 b formed at the upper end of the shoulder 230. As an example, for example, a female screw is formed.

  On the other hand, the shoulder 230 includes an attachment portion 232 formed with a positioning surface 232b that contacts the contact surface 217b of the housing body 212, a reduced diameter portion 233 that continues from the attachment portion 232 in the height direction, and a reduced diameter portion 233. Further, a projecting portion 234 that tapers toward the tip is integrally formed. And the 1st surface 234a located in the edge part of the protrusion part 234 functions as a shoulder surface which contacts a workpiece | work when performing friction stir welding.

  The outer shape of the attachment portion 232 is an attachment structure having a shape corresponding to the holding surface 217a of the housing body 212 described above. As an example, the held surface 232a of the attachment portion 232 is formed with a male screw, for example. In addition, a second accommodation hole H <b> 2 that constitutes a part of the accommodation hole SH of the housing 210 is formed inside the shoulder 230.

  Further, the projecting portion 234 is formed with a first housing hole H1 that is connected to the second housing hole H2 and opens in the first surface 234a, and a part of the pin body 224 of the stirring pin 220 is housed. The Here, as in the case of the first embodiment, the first accommodation hole H1 and the second accommodation hole H2 are set to have a larger diameter than the outer diameter of the pin body 224, and the second accommodation hole H2 is The hole diameter is set to be larger than that of the first accommodation hole H1.

  In the friction stir welding tool 200 according to the second embodiment of the present invention, the shoulder 230 is formed with a discharge hole 238 that allows the accommodation hole SH to communicate with the outside of the shoulder 230. Here, similarly to the case of the first embodiment, the discharge hole 238 is preferably formed at a position including at least the boundary B between the first accommodation hole H1 and the second accommodation hole H2.

  5A to 5C are diagrams for explaining a specific configuration of the shoulder shown in FIG. 4B, in which FIG. 5A shows a side view, FIG. 5B shows a bottom view, and FIG. 5C shows a top view. . As shown in FIG. 5A, in the shoulder 230, the mounting portion 232, the reduced diameter portion 233, and the protruding portion 234 described above are integrally formed, and the lower end surface of the protruding portion 234 is the first surface 234a. In addition, a male screw is formed on the held surface 232 a of the mounting portion 232, and a positioning surface 232 b that contacts the contact surface 217 b of the housing body 212 is formed at the upper end of the mounting portion 232.

  As shown in FIGS. 5B and 5C, the shoulder 230 is formed with a discharge hole 238 that allows the accommodation hole SH and the outside of the shoulder 230 to communicate with each other in a manner in which a part thereof is cut away. At this time, the discharge hole 238 is configured so that the plastically flowing surplus metal M that is a part of the workpiece W is discharged from the second housing hole H2 to the outside of the shoulder 230 along the flow generated by the rotation of the stirring pin 220. It may be formed.

  As an example, the shoulder 230 includes a connection position P1 where the inner peripheral surface 238a of the discharge hole 238 and the inner peripheral surface H2a of the second accommodation hole H2 are connected in the rotation direction R of the stirring pin 220. Is formed so as to include the tangential direction T1 of the inner periphery of the second accommodation hole H2 at the connection position P1. Thereby, the surplus metal M can be continuously and smoothly discharged | emitted by rotation of the pin main body 224 in joining.

  Further, as shown in FIG. 5B, the outer surface of the reduced diameter portion 233 has a prismatic shape (in the case of FIG. 5B, a hexagonal prism) as an example. This makes it easy to grip the mounting portion 232 of the shoulder 230 when screwed into the holding portion 217 of the housing body 212.

  With this configuration, the friction stir welding tool 200 according to the second embodiment of the present invention has a structure in which the housing 210 is detachably attached to the tip of the housing main body 212 in addition to the effects obtained in the first embodiment. For example, when the first surface 234a that is always in contact with the workpiece W during friction stir welding is damaged due to wear or the like, only the shoulder 230 can be replaced as a consumable, so the running cost as a friction stir welding tool can be reduced. Can be reduced. Further, since it is not necessary to replace the entire housing 210, it is possible to save the trouble of tool replacement. Furthermore, the penetration amount of the surplus metal M into the accommodation hole SH can be adjusted by using a housing having a different hole diameter of the first accommodation hole H1 with respect to the shape of the pin body 224 determined by the joining conditions.

<Example 3>
Next, the outline of the friction stir welding tool according to Example 3 of the present invention will be described with reference to FIG. In the following description, the configuration of the friction stir welding apparatus to which the friction stir welding tool according to the third embodiment is applied is the same as that of the first embodiment except for the friction stir welding tool including the detachable shoulder. The re-explanation here is omitted.

  6A and 6B are cross-sectional views showing specific features of the main part of the friction stir welding tool according to the third embodiment of the present invention. FIG. 6A shows an outline of the tool tip in use, and FIG. Shows the outline of the mounting structure of the housing body and the shoulder. As shown in FIG. 6A, the friction stir welding tool 300 according to the third embodiment of the present invention includes a housing 310 installed on the spindle frame 14 shown in FIG. 1 and a stirring pin 320 connected to the rotary spindle 16. Composed. The housing 310 has a housing main body 312 and a shoulder 330 that is detachably attached to the lower end of the housing main body 312. The housing 310 has a shoulder 330 attached to the housing main body 312. The housing hole SH is formed, and the stirring pin 320 is rotatably accommodated.

  As shown in FIG. 6B, the housing main body 312 of the housing 310 is formed with a holding portion 317 that holds a shoulder 330 described later while opening the lower end thereof. The holding portion 317 of the housing body 312 includes a holding surface 317 a that holds the held surface 332 a of the shoulder 330, an upper contact surface 317 b that contacts an upper positioning surface 332 b that determines the position of the shoulder 330 in the rotation axis C direction, and a shoulder For example, a female screw is formed on the holding surface 317a. The side contact surface 317c contacts the side positioning surface 332c that determines the radial position of the rotation axis C of 330.

  On the other hand, the shoulder 330 includes a mounting portion 332 in which a held surface 332a, an upper positioning surface 332b, and a side positioning surface 332c are formed, a reduced diameter portion 333 continuous in the height direction from the mounting portion 332, and a reduced diameter portion 333. And a projecting portion 334 that is tapered toward the tip. And the 1st surface 334a located in the edge part of the protrusion part 334 functions as a shoulder surface which contacts a workpiece | work when performing friction stir welding.

  In addition, a second accommodation hole H2 constituting a part of the accommodation hole SH of the housing 310 is formed inside the shoulder 330, and the second accommodation hole H2 and the outside are connected to the protruding portion 334. A first accommodation hole H1 is formed. Here, as in the case of the first embodiment, the first housing hole H1 and the second housing hole H2 have a hole diameter larger than the outer diameter of the pin body 324, and the second housing hole H2 Is set so that the hole diameter is larger than that of the first accommodation hole H1.

  The outer shape of the mounting portion 332 is a mounting structure having a shape corresponding to the holding portion 317 of the housing main body 312 described above. As an example, the held surface 332a of the mounting portion 332 is formed with a male screw, for example. The upper positioning surface 332 b formed at the upper end of the mounting portion 332 contacts the upper contact surface 317 b of the housing body 312 and determines the position of the shoulder 330 in the direction of the rotation axis C. Further, the side positioning surface 332 c formed on the side surface of the upper portion of the attachment portion 332 contacts the side contact surface 317 c of the housing body 312 and determines the radial position of the rotation axis C of the shoulder 330.

  In the friction stir welding tool 300 according to the third embodiment of the present invention, the shoulder 330 is formed with a discharge hole 338 that allows the accommodation hole SH to communicate with the outside of the shoulder 330. Here, as in the case of the second embodiment, the discharge hole 338 is preferably formed at a position including at least the boundary B between the second accommodation hole H2 and the first accommodation hole H1. Further, the discharge hole 338 is formed so that the plastically flowing surplus metal that is a part of the work is discharged from the second accommodation hole H2 to the outside of the shoulder 330 along the flow generated by the rotation of the stirring pin 320. May be.

  With this configuration, in the friction stir welding tool 300 according to the third embodiment of the present invention, the shoulder 330 contacts the upper contact surface 317b of the housing body 312 and the side contact surface 317c of the housing body 312. And a side positioning surface 332c that comes into contact with. For this reason, in addition to the effects obtained in the first and second embodiments, the shoulder 330 is attached to the housing main body 312 by forming the side positioning surface 332c that contacts the side abutting surface 317c of the housing main body 312 with a fitting structure. When mounting, the shoulder 330 is accurately positioned with respect to the housing main body 312 in the direction of the rotation axis C and the radial direction of the rotation axis C, and even when the shoulder 330 is replaced, it is easily substantially the same before and after replacement. Bonding quality can be maintained.

<Example 4>
Next, the outline of the friction stir welding tool according to Example 4 of the present invention will be described with reference to FIG. In the following description, the configuration of the friction stir welding apparatus to which the friction stir welding tool according to the fourth embodiment is applied is the same as that of the first embodiment except for the friction stir welding tool including the detachable shoulder. The re-explanation here is omitted.

  7A and 7B are cross-sectional views showing specific features of the main part of the friction stir welding tool according to Example 4 of the present invention. FIG. 7A shows an outline of the tool tip in use, and FIG. Shows the outline of the mounting structure of the housing body and the shoulder. As shown in FIG. 7A, a friction stir welding tool 400 according to Embodiment 4 of the present invention includes a housing 410 attached to the spindle frame 14 shown in FIG. 1, a stirring pin 420 connected to the rotating spindle 16, Consists of.

  As in the second and third embodiments, the housing 410 includes a housing body 412 and a shoulder 430 that is detachably attached to the lower end of the housing body 412, and the shoulder 430 is attached to the housing body 412. In this state, an accommodation hole SH is formed inside thereof, and the agitation pin 420 is accommodated rotatably. As shown in FIG. 7B, the housing main body 412 of the housing 410 is formed with a holding portion 417 for holding the shoulder 430 on the inner surface thereof while the lower end thereof is opened as in the third embodiment.

  On the other hand, as in the third embodiment, the shoulder 430 includes an attachment portion 432 attached to the housing body 412, a reduced diameter portion 433 that continues in the height direction from the attachment portion 432, and a further reduction diameter portion 433 toward the tip. A tapered projecting portion 434 is integrally formed, and the first surface 434a located at the end of the projecting portion 434 functions as a shoulder surface that comes into contact with the workpiece when performing friction stir welding. In addition, a second housing hole H2 constituting a part of the housing hole SH of the housing 410 is formed inside the shoulder 430, and the projecting portion 434 is connected to the second housing hole H2, A first accommodation hole H1 that opens to one surface 434a is formed.

  Here, as in the case of the first embodiment, as an example, the first accommodation hole H1 and the second accommodation hole H2 have a hole diameter larger than the outer diameter of the pin body 424, The housing hole H2 is set so that the hole diameter is larger than that of the first housing hole H1. In the friction stir welding tool 400 according to the fourth embodiment, the lower end portion of the second accommodation hole H2 constituting a part of the accommodation hole SH is smoothly directed toward the boundary B with the first accommodation hole H1. A curved surface 433a having a reduced diameter is formed, and even if the surplus metal M enters the accommodation hole SH, it does not stagnate below the second accommodation hole H2.

  Also in the friction stir welding tool 400 according to the fourth embodiment of the present invention, the shoulder 430 is formed with a discharge hole 438 that allows the accommodation hole SH to communicate with the outside of the shoulder 430. Here, similarly to the case of the third embodiment, the discharge hole 438 is preferably formed at a position including at least the boundary B between the first accommodation hole H1 and the second accommodation hole H2. Further, the discharge hole 438 is formed so that the plastically flowing surplus metal M that is a part of the work is discharged from the second receiving hole H2 to the outside of the shoulder 430 along the flow generated by the rotation of the stirring pin 420. May be.

  With this configuration, the friction stir welding tool 400 according to the fourth embodiment of the present invention has the second accommodation hole that constitutes a part of the accommodation hole SH of the shoulder 430 in addition to the effects obtained in the first to third embodiments. A curved surface 433a that is smoothly reduced in diameter toward the boundary B with the first accommodation hole H1 is formed at the lower end of H2, so that it passes through the gap G between the pin body 424 and the first accommodation hole H1 to the inside. It can suppress that the excess metal M which penetrate | invaded retains in the lower part of the 2nd accommodation hole H2.

<Example 5>
FIG. 8 is a cross-sectional view showing an outline of the tool tip when the friction stir welding tool according to the fifth embodiment of the present invention is used. In the following description, the configuration of the friction stir welding apparatus to which the friction stir welding tool according to the fifth embodiment is applied is the same as that of the first embodiment except for the friction stir welding tool including the detachable shoulder. The re-explanation here is omitted.

  As shown in FIG. 8, the friction stir welding tool 500 according to the fifth embodiment of the present invention includes a housing 510 installed on the spindle frame 14 shown in FIG. 1 and a stirring pin 520 connected to the rotating spindle 16. Composed. Similarly to the second and third embodiments, the housing 510 includes a housing main body 512 and a shoulder 530 that is detachably attached to the lower end of the housing main body 512. The housing 510 has a shoulder 530. In the state where is attached, the accommodation hole SH is formed inside thereof, and the stirring pin 520 is rotatably accommodated.

  In the friction stir welding tool 500 according to the fifth embodiment of the present invention, a substantially tapered second receiving hole H2 having a diameter reduced toward the lower portion is formed inside the shoulder 530. The shoulder 530 is formed with a discharge hole 538 that communicates the second accommodation hole H <b> 2 and the outside of the shoulder 530. Here, since the normal friction stir welding tool has a structure in which the first surface 534a is always in contact with the workpiece W, the shoulder 530 including the first surface 534a is formed of a metal material such as steel. At this time, the processing of the outer surface and the inner surface of the shoulder 530 is often performed by machining such as turning, but the shoulder 530 according to the modification shown in FIG. 8 has a large tapered inner surface. Can be turned.

  With this configuration, in the friction stir welding tool 500 according to the fifth embodiment of the present invention, in addition to the effects obtained in the first to fourth embodiments, the discharge hole 538 is substantially tapered from the second accommodation hole H2 to the shoulder 530. By communicating with the outside, it is possible to suppress surplus metal (see symbol M in FIG. 3) that has entered the second accommodation hole H2 from staying in the lower portion of the second accommodation hole H2. Moreover, by making the shape of the shoulder 530 suitable for machining, the number of machining steps can be reduced, and the shoulder 530 itself can be reduced in weight.

<Example 6>
Next, the outline of the friction stir welding tool according to Example 6 of the present invention will be described with reference to FIG. In the following description, only the difference in configuration from the friction stir welding tool shown in the first to fifth embodiments will be described, and the same reference numerals as those in the second embodiment are used for other common configurations. The description will be made and the illustration will be omitted.

  9A to 9C are views for explaining a specific configuration of a shoulder applied to a friction stir welding tool according to a sixth embodiment of the present invention. FIG. 9A is a side view, and FIG. 9B is a bottom view. FIG. 9C shows a top view, respectively. As shown in FIG. 9A, in the shoulder 630 in the sixth embodiment, the attachment portion 632, the reduced diameter portion 633, and the protruding portion 634 are integrally formed as in the case of the third embodiment, and the end portion of the protruding portion 634 is formed. The first surface 634a located on the surface functions as a shoulder surface that comes into contact with the workpiece when performing friction stir welding. The held surface 632 a of the mounting portion 632 is formed with a male screw, and a positioning surface 632 b that contacts the contact surface 217 b of the housing body 212 is formed at the upper end of the upper end portion 632.

  As shown in FIGS. 9B and 9C, the shoulder 630 is formed with two discharge holes 638 and 639 that communicate the second housing hole H <b> 2 and the outside of the shoulder 630 in a manner in which a part thereof is cut away. Yes. At this time, the discharge holes 638 and 639 are formed on the outside of the shoulder 630 from the accommodation hole SH along the flow generated by the rotation of the stirring pin 220 by the plastically flowing surplus metal (see symbol M in FIG. 3) that is a part of the workpiece W. You may form so that it may be discharged.

  As an example of such a discharge hole, as in the case of the second embodiment, the shoulder 630 includes an inner peripheral surface 638a of the discharge hole 638 and an inner peripheral surface H2a of the second accommodation hole H2 in the rotation direction R of the stirring pin. Includes a connection position P1 to be connected. At this time, the discharge hole 638 is formed so as to include the tangential direction T1 of the inner periphery of the second accommodation hole H2 at the connection position P1.

  Further, the shoulder 630 includes a connection position P2 where the inner peripheral surface 639a of the discharge hole 639 and the inner peripheral surface H2a of the second accommodation hole H2 are connected in the rotation direction R of the stirring pin. At this time, the discharge hole 639 is formed so as to include the tangential direction T2 of the inner periphery of the second accommodation hole H2 at the connection position P2. Thereby, surplus metal can be continuously and smoothly discharged | emitted from the two discharge holes 638 and 639 to the exterior by rotation of the stirring pin in joining.

  The two discharge holes 638 and 639 are preferably arranged so as to face each other in the circumferential direction of the second accommodation hole H2, that is, at equal intervals. As a result, the rigidity of the entire shoulder 630 to be cut out can be balanced, and the excess metal can be discharged efficiently.

  With this configuration, the friction stir welding tool according to the sixth embodiment of the present invention has the discharge holes 638 and 639 formed in the shoulder 630 in addition to the effects obtained in the first to fifth embodiments. Efficiency can be further increased. As a result, excessive frictional heat generation between the stirring pin and the surplus metal can be further suppressed, and a reduction in strength or breakage of the stirring pin can be suppressed.

  As mentioned above, although the typical Example by this invention and the modification accompanying this were described, this invention is not necessarily limited to this, A person skilled in the art can change suitably. That is, those skilled in the art will be able to find various alternative embodiments and modifications without departing from the scope of the appended claims.

  For example, although the friction stir welding tool and the friction stir welding apparatus in Examples 1 to 6 have been exemplified for use in continuous joining of members, the use for point joining is not excluded.

  For example, although the discharge holes formed in the housing in the first to sixth embodiments are illustrated, the housing may be further provided with a structure for receiving the surplus metal so that the surplus metal discharged from the discharge hole does not fall on the work upper surface. Good. In addition, although the shoulder surface (first surface) that comes into contact with the workpiece when performing friction stir welding in Examples 1 to 6 is illustrated, the shoulder surface has not only a flat shape but also a concave shape or a convex shape. Alternatively, a cross groove, a spiral groove, or the like may be formed on the shoulder surface.

  In the second to fifth embodiments, the case where the housing and the shoulder are screwed is illustrated. However, for example, other attachment structures such as a suction structure using a magnetic force or a vacuum pressure or a chucking structure using a claw or the like are applied. May be.

  In the sixth embodiment, the case where two holes are formed as a plurality of discharge holes is illustrated. However, in consideration of the overall rigidity of the shoulder and the discharge efficiency of surplus metal, three or more discharge holes are formed. You may comprise as follows. Further, in the sixth embodiment, the case where a plurality of discharge holes are formed in the detachable shoulder shown in the second to fifth embodiments is exemplified. However, such a plurality of discharge holes are formed in the housing body shown in the first embodiment. You may comprise so that it may form.

DESCRIPTION OF SYMBOLS 1 Friction stir welding apparatus 10 Main-body part 12 Main stand 14 Main spindle frame 16 Rotation main spindle 18 Main spindle feed apparatus 20 Work conveyance part 22 Processing table 24 Processing table feed apparatus 30 Control part 32 Numerical control apparatus 34 Interface 36 Memory 100, 200, 300 , 400, 500 Friction stir welding tool 110, 210, 310, 410, 510 Housing 112, 212, 312, 412, 512 Housing body 113 Reduced diameter portion 114 Projection portion 114a First surface 118, 238, 338, 438, 538, 638, 639 Discharge holes 120, 220, 320, 420, 520 Stirring pins 122, 222 Pin holders 124, 224, 324, 424, 524 Pin bodies 124a, 224a Stirring portions 217, 317, 417 Holding portions 230, 330, 430 530 , 630 Shoulder 232, 332, 432, 632 Mounting portion 233, 333, 433, 633 Reduced diameter portion 234, 334, 434, 534 Protruding portion 234a, 334a, 434a, 534a, 634a First surface

Claims (13)

A stirring pin having a rotating shaft, and a housing having a first surface;
The housing contains the agitating pin so as to be relatively rotatable around the rotation axis, and includes a receiving hole opened in the first surface,
The stirring pin includes, at one end along the rotating shaft, a stirring portion that protrudes from the first surface in a state of being accommodated in the accommodation hole and is inserted into the workpiece,
The housing is formed with a discharge hole communicating with the housing hole and the outside of the housing,
The accommodation hole includes a first accommodation hole and a second accommodation hole connected to each other along the rotation axis,
The first accommodation hole opens in the first surface;
The second receiving hole has a larger hole diameter than the first receiving hole,
The drainage hole is formed at a position including a boundary between the first accommodation hole and the second accommodation hole. The housing comprises a shoulder having the first surface and the discharge hole, and a housing main body separately.
The shoulder includes an attachment portion attached to the housing body,
The friction stir welding tool according to claim 1, wherein the housing body includes a holding portion for holding the attachment portion. The attachment portion includes a positioning surface that identifies a position when the shoulder is attached to the housing body,
The friction stir welding tool according to claim 2, wherein the holding portion includes a contact surface that contacts the positioning surface. The discharge hole is formed so that the work that has entered the inside of the housing is discharged from the housing hole to the outside of the housing along a flow generated by rotation of the stirring pin. Item 4. The friction stir welding tool according to any one of Items 1 to 3. 5. The friction stir welding according to claim 1, wherein two or more of the discharge holes are formed and are arranged so that positions where the discharge holes are connected to the accommodation holes are equally spaced from each other. Tools. 6. The friction stirrer according to claim 1, wherein at least an inner surface of the first accommodation hole is coated with a coating having low affinity with the workpiece. Joining tool. The friction stir welding tool according to any one of claims 1 to 6, wherein the first surface of the housing constitutes a shoulder surface in contact with the workpiece. The stirring pin comprises a pin body having the stirring unit and a pin holder separately,
The friction stir welding tool according to any one of claims 1 to 7, wherein the pin body is attached to the pin holder on the opposite side of the agitating portion along the rotation axis. A spindle stock including a rotary spindle, a friction stir welding tool attached to the spindle stock, a machining table for holding a workpiece, and a numerical control device for controlling the relative movement of the spindle stock and the machining table. A friction stir welding apparatus comprising:
The friction stir welding tool includes a stirring pin having a rotating shaft and a housing having a first surface,
The housing contains the agitating pin so as to be relatively rotatable around the rotation axis, and includes a receiving hole opened in the first surface,
The stirring pin includes, at one end along the rotating shaft, a stirring portion that protrudes from the first surface in a state of being accommodated in the accommodation hole and is inserted into the workpiece,
The housing is formed with a discharge hole communicating with the outside of the housing from the accommodation hole,
The accommodation hole of the friction stir welding tool includes a first accommodation hole and a second accommodation hole connected to each other,
The first accommodation hole opens in the first surface and has a smaller hole diameter than the second accommodation hole,
The friction stir welding apparatus according to claim 1, wherein the discharge hole is formed from a position including a boundary between the first accommodation hole and the second accommodation hole. The housing of the friction stir welding tool comprises a shoulder having the first surface and the discharge hole, and a housing body, which are separated from each other.
The shoulder includes an attachment portion attached to the housing body,
The friction stir welding apparatus according to claim 9, wherein the housing body includes a holding portion that holds the attachment portion. The stirrer pin of the friction stir welding tool comprises a pin body having the stirrer and a pin holder separately.
11. The friction stir welding apparatus according to claim 9, wherein the pin main body is attached to the pin holder on the opposite side of the stirring portion along the rotation axis. The friction stir welding apparatus according to any one of claims 9 to 11, wherein the first surface of the housing of the friction stir welding tool constitutes a shoulder surface in contact with the workpiece. The friction stir welding apparatus according to any one of claims 9 to 12, wherein the headstock further includes a gas flow supply mechanism that supplies a gas flow into the housing.

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