阅读说明：本技术 摩擦搅拌接合装置 (Friction stir welding device ) 是由 宫胁章嘉 佐山满 栗原大知 于 2021-05-26 设计创作，主要内容包括：提供能够抑制被接合构件的摩擦搅拌接合时产生的切屑向搅拌头与肩构件之间的间隙侵入的摩擦搅拌接合装置。摩擦搅拌接合装置(10)具备搅拌头(26)、肩构件(18)、凹部(31)及环状构件(16)。搅拌头在多个被接合构件(21、22)的接合部(23)一边旋转一边按压。肩构件形成为在搅拌头的相对于旋转轴(28)的径向的外侧包围搅拌头。凹部形成于搅拌头的外周(26a)及肩构件(18)的内周(18a)中的至少任一方。环状构件嵌合于凹部。(Provided is a friction stir welding device capable of suppressing the intrusion of chips generated during friction stir welding of members to be welded into a gap between a stirring head and a shoulder member. A friction stir welding device (10) is provided with a stir head (26), a shoulder member (18), a recess (31), and an annular member (16). The stirring head is pressed against the joining sections (23) of the plurality of joined members (21, 22) while rotating. The shoulder member is formed so as to surround the stirring head on the outer side of the stirring head in the radial direction with respect to the rotating shaft (28). The recessed portion is formed on at least one of the outer periphery (26a) of the stirring head and the inner periphery (18a) of the shoulder member (18). The annular member is fitted in the recess.)

1. A friction stir welding apparatus, wherein,

the friction stir welding device includes:

a stirring head that rotates and presses a joint portion of the plurality of members to be joined;

a shoulder member surrounding the pin outside the pin in a radial direction with respect to a rotation axis;

a recess formed in at least one of an outer periphery of the pin and an inner periphery of the shoulder member; and

an annular member fitted into the recess.

2. The friction stir welding apparatus according to claim 1,

the recessed portion is formed in the stirring head so that at least a part of an inner peripheral end portion of the annular member enters the recessed portion,

the inner peripheral end portion has an inner tapered portion that is inclined so as to approach the joint portion from the inside toward the outside in the radial direction.

3. The friction stir welding apparatus according to claim 1 or 2,

the recessed portion is formed in the stirring head so that at least a part of an inner peripheral end portion of the annular member enters the recessed portion,

a convex portion protruding toward the joining portion side is provided at an outer peripheral end portion of the annular member,

the convex portion has an outer tapered portion that is inclined so as to approach the joint portion from the inside toward the outside in the radial direction.

4. The friction stir welding apparatus according to claim 1 or 2,

the concave part is formed on the stirring head,

the annular member has a pair of end portions opposed to each other in a circumferential direction of the rotary shaft, and has an overlapping portion extending in the circumferential direction and overlapping in an axial direction of the rotary shaft at the pair of end portions,

one of the pair of end portions has: a first engagement portion that forms a portion of the overlapping portion on the engagement portion side in the axial direction; and a first surface portion formed at an end portion in the circumferential direction in the first joining site,

the other of the pair of end portions has: a second engaging portion that forms a portion of the overlapping portion on the opposite side of the engaging portion in the axial direction; and a second surface portion circumferentially opposed to the first surface portion,

at least one of the first surface portion and the second surface portion is inclined such that an interval between the first surface portion and the second surface portion widens in the circumferential direction as it goes toward the joint portion.

5. The friction stir welding apparatus according to claim 3, wherein,

the concave part is formed on the stirring head,

the annular member has a pair of end portions opposed to each other in a circumferential direction of the rotary shaft, and has an overlapping portion extending in the circumferential direction and overlapping in an axial direction of the rotary shaft at the pair of end portions,

one of the pair of end portions has a first engagement portion that forms a portion of the overlapping portion located on the engagement portion side in the axial direction, and a first surface portion that forms the circumferential end portion of the first engagement portion,

the other of the pair of end portions has a second joining portion forming a portion of the overlapping portion on the opposite side of the joining portion in the axial direction, and a second surface portion circumferentially opposed to the first surface portion,

at least one of the first surface portion and the second surface portion is inclined such that an interval between the first surface portion and the second surface portion widens in the circumferential direction as it goes toward the joint portion.

6. The friction stir welding apparatus according to claim 1,

the recess is formed in the shoulder member in such a manner that at least a part of the outer peripheral end of the ring-shaped member enters the recess,

the outer peripheral end portion has an outer tapered portion that is inclined toward the joint portion from the outside toward the inside in the radial direction.

7. The friction stir welding apparatus according to claim 1 or 6,

the recess is formed in the shoulder member in such a manner that at least a part of the outer peripheral end of the ring-shaped member enters the recess,

a convex portion protruding toward the engagement portion side is provided at an inner peripheral end portion of the annular member,

the convex portion has an inner tapered portion that is inclined toward the joint portion as going from the outside to the inside in the radial direction.

Technical Field

The present invention relates to a friction stir welding apparatus.

Background

As a friction stir welding apparatus, for example, a structure is known in which a tool (hereinafter, referred to as a "stir head") is moved while rotating a member to be welded, and the member to be welded is welded by frictional heat generated between the stir head and the member to be welded. In this structure, for example, a groove portion is formed in the outer peripheral surface of the stirring head along the rotation axis direction, and the stirring head is connected to the sleeve (hereinafter referred to as a shoulder member) via the balls fitted in the groove portion. Thus, the rotation of the shoulder member is transmitted to the stirring head via the balls, and the stirring head is rotated. The balls are slid while the shoulder member and the stirring head are rotated, and the stirring head is moved in the axial direction of the rotating shaft. Further, according to this structure, the stirring head is stably held by the shoulder member (see, for example, japanese laid-open patent publication No. 2013-121606).

As a configuration of the friction stir welding apparatus, for example, the following configurations are known: a groove is formed in the surface of the stirring head along the direction of the rotation axis, and the stirring head is connected to the shoulder member via a guide rod fitted in the groove. Thus, the rotation of the pin is transmitted to the shoulder member via the guide rod, and the shoulder member is rotated. The guide rod is slid while the pin and the shoulder member are rotated, and the pin is moved in the axial direction of the rotary shaft. Further, according to this structure, the stirring head is stably held by the shoulder member. (see, for example, Japanese patent application laid-open No. 2006-858).

Disclosure of Invention

However, the friction stir welding device of japanese laid-open patent publication nos. 2013-121606 and 2006-858 forms a gap (clearance) between the stirring head and the shoulder member. Therefore, it is considered that chips (e.g., burrs, etc.) generated when joining the members to be joined by frictional heat intrude into the gap between the stirring head and the shoulder member, which may affect the quality of the joined portion of the members to be joined.

An object of an aspect of the present invention is to provide a friction stir welding apparatus capable of suppressing intrusion of chips generated at the time of friction stir welding of members to be welded into a gap between a stirring head and a shoulder member.

A friction stir welding apparatus according to a first aspect of the present invention includes: a stirring head that rotates and presses a joint portion of the plurality of members to be joined; a shoulder member surrounding the pin outside the pin in a radial direction with respect to a rotation axis; a recess formed in at least one of an outer periphery of the pin and an inner periphery of the shoulder member; and an annular member fitted in the recess.

According to this configuration, the shoulder member is formed so as to surround the pin outside the pin in the radial direction with respect to the rotation shaft. Thus, for example, in a state where the pin is rotated about the rotation axis, the pin can be stably held by the shoulder member.

In addition, a recessed portion is formed on at least one of the outer periphery of the stirring head and the inner periphery of the shoulder member, and an annular member is fitted in the recessed portion. Therefore, the outer side portion of the annular member protrudes from the recess, and the gap between the stirring tip and the shoulder member can be closed by the annular member. This makes it possible to suppress, with the annular member, the intrusion of chips (for example, burrs) generated at the time of friction stir welding of the members to be welded into the gap between the tool bit and the shoulder member. Therefore, the quality of the joint portion where the plurality of members to be joined are friction stir welded by the stir head can be improved.

Further, by fitting the annular member into the recess, heat transferred to the pin at the time of friction stir welding can be transferred (dissipated) to the shoulder member via the annular member. This can expect the heat removing effect of the stirring head.

A second aspect of the present invention may be the friction stir welding apparatus according to the first aspect, wherein the recessed portion is formed in the stir head such that at least a portion of an inner peripheral end portion of the annular member enters the recessed portion, and the inner peripheral end portion has an inner tapered portion that is inclined so as to approach the welding portion as going from the inside toward the outside in the radial direction.

Therefore, chips generated at the time of friction stir welding of the members to be welded can enter the recess, and the pressing force generated by the chips can be applied to the inner tapered portion. The pressing force generated by the chips is divided into a first component force pressing the inner peripheral end portion toward the opposite side of the joint portion and a second component force pressing the inner peripheral end portion toward the radial outside at the inner tapered portion.

The inner peripheral end of the annular member can be brought into close contact with the recess (i.e., the stirring head) by the first component force. Further, the outer peripheral end of the annular member can be brought into close contact with the shoulder member by the second component force. Here, the inner tapered portion is acted upon by a force acting radially outward by the centrifugal force of the chips entering the recess in addition to the second component force. Therefore, the outer peripheral end of the annular member is more closely attached to the shoulder member. This makes it possible to close (fill) the gap between the stirring head and the shoulder member with the annular member, and to suppress the intrusion of chips into the gap between the stirring head and the shoulder member with the annular member more favorably.

Further, by bringing the annular member into close contact with the pin and the shoulder member, the heat of the pin can be efficiently transferred to the shoulder member via the annular member during friction stir welding. Thus, the heat removal effect of the stirring head can be improved by the annular member.

A third aspect of the present invention may be the friction stir welding apparatus according to the first or second aspect, wherein the recessed portion is formed in the stirring head such that at least a part of an inner peripheral end portion of the annular member enters the recessed portion, the annular member has a protruding portion protruding toward the welding portion at an outer peripheral end portion thereof, and the protruding portion has an outer tapered portion inclined so as to approach the welding portion as going from the inner side toward the outer side in the radial direction.

Therefore, chips generated at the time of friction stir welding of the members to be welded can be guided radially inward (i.e., the inner peripheral end portion of the annular member) by the outer tapered portion. This enables the pressing force generated by the chips to be efficiently applied to the inner tapered portion of the inner peripheral end portion. The pressing force generated by the chips is divided into a first component force pressing the inner peripheral end portion toward the side opposite to the joint portion and a second component force pressing the inner peripheral end portion toward the outside in the radial direction at the inner tapered portion.

The first component force enables the inner peripheral end of the annular member to be efficiently brought into close contact with the recess (i.e., the stirring head). In addition, the outer peripheral end of the annular member can be brought into close contact with the shoulder member efficiently by the second component force. This makes it possible to close (fill) the gap between the stirring tip and the shoulder member with the annular member, and to suppress the intrusion of chips into the gap between the stirring tip and the shoulder member with higher efficiency with the annular member.

Further, by making the annular member contact the head and the shoulder member efficiently, the heat of the head can be transmitted to the shoulder member via the annular member more efficiently during friction stir welding. This can further improve the heat removal effect of the stirring head by the annular member.

A fourth aspect of the present invention may be the friction stir welding apparatus according to any one of the first to third aspects, wherein the recessed portion is formed in the stirring head, the annular member has a pair of end portions that face each other in a circumferential direction of the rotating shaft, and an overlapping portion that extends in the circumferential direction and overlaps in an axial direction of the rotating shaft is provided at the pair of end portions, and one of the pair of end portions has: a first engagement portion that forms a portion of the overlapping portion on the engagement portion side in the axial direction; and a first surface portion formed at an end portion in the circumferential direction in the first joining site, the other of the pair of end portions having: a second engaging portion that forms a portion of the overlapping portion on the opposite side from the engaging portion in the axial direction; and a second surface portion that is circumferentially opposed to the first surface portion, at least one of the first surface portion and the second surface portion being inclined such that an interval between the first surface portion and the second surface portion widens in the circumferential direction as the first surface portion approaches the joint portion.

According to this configuration, the stirring head is formed with a recess, and the annular member is fitted in the recess. Therefore, the outer portion of the annular member protrudes radially outward from the recess and is disposed in the gap between the stirring head and the shoulder member. The annular portion has an overlapping portion where the first engagement portion and the second engagement portion overlap in the axial direction. The first engagement portion is disposed on the side of the overlapping portion in the axial direction closer to the engagement portion.

Therefore, chips generated at the time of friction stir welding of the members to be welded intrude into the first welding portion, and a pressing force pressing toward the opposite side of the welding portion can act on the first welding portion. This allows the first joining portion to be pressed against the second joining portion, thereby bringing the overlapping portions into close contact with each other. Further, the annular member can be brought into close contact with the recess (i.e., the stirring head) by the pressing force of the chips.

At least one of the first surface portion and the second surface portion of the pair of end portions is inclined so that the distance between the surface portions widens in the circumferential direction as it approaches the joint portion.

Therefore, chips generated at the time of friction stir welding of the members to be welded intrude into the inclined surface portion, and a pressing force by the chips can be applied to the inclined surface portion. The pressing force generated by the chips is divided into a first component force pressing toward the opposite side of the joint and a second component force pressing so as to widen the interval between the first surface and the second surface at the inclined surface. That is, the annular member can be expanded in diameter by the second component force and can be brought into close contact with the shoulder member.

In this way, the overlapping portion can be brought into close contact with the pressing force of the chips, and the annular member can be brought into close contact with the recess (i.e., the stirring head). In addition, the annular member can be expanded in diameter by the second component force to be in close contact with the shoulder member. Thus, the gap between the stirring head and the shoulder member can be closed (filled) by the annular member, and the annular member can suppress the intrusion of chips into the gap between the stirring head and the shoulder member.

Further, by bringing the annular member into close contact with the pin and the shoulder member, the heat of the pin can be efficiently transferred to the shoulder member via the annular member during friction stir welding. Thus, the heat removal effect of the stirring head can be improved by the annular member.

Here, for example, when the first surface portion of the pair of end portions is inclined, the first surface portion can be pressed toward the opposite side of the joint portion by the first component force. Therefore, the first joining portion can be pressed against the second joining portion by the first component force, and the overlapping portion can be more reliably brought into close contact. This makes it possible to more reliably suppress the intrusion of chips into the gap between the pin and the shoulder member by the annular member.

A fifth aspect of the present invention may be the friction stir welding apparatus according to the first aspect, wherein the recessed portion is formed in the shoulder member so that at least a part of an outer peripheral end portion of the annular member enters the recessed portion, and the outer peripheral end portion has an outer tapered portion that is inclined toward the joint portion from the outside toward the inside in the radial direction.

According to this configuration, the annular member has an outer tapered portion at an outer peripheral end portion thereof that enters the recess. The outer tapered portion is formed to be inclined toward the joint portion from the radially outer side toward the radially inner side.

Therefore, chips generated at the time of joining the joined members enter the concave portion, and the pressing force generated by the chips can be applied to the outer tapered portion. The pressing force generated by the chips is divided into a first component force pressing the outer peripheral end portion toward the opposite side of the joint portion and a second component force pressing the outer peripheral end portion toward the radial outside at the outer tapered portion.

The outer peripheral end of the annular member can be brought into close contact with the recess (i.e., the shoulder member) by the first component force. Further, the inner peripheral end of the annular member can be brought into close contact with the stirring head by the second component force. Thus, the gap between the shoulder member and the pin can be closed (filled) by the annular member, and the intrusion of chips into the gap between the shoulder member and the pin can be suppressed by the annular member.

Further, by bringing the annular member into close contact with the pin and the shoulder member, the heat of the pin can be efficiently transferred to the shoulder member via the annular member during friction stir welding. Thus, the heat removal effect of the stirring head can be improved by the annular member.

A sixth aspect of the present invention may be the friction stir welding apparatus according to the first or fifth aspect, wherein the recessed portion is formed in the shoulder member so that at least a part of an outer peripheral end portion of the annular member enters the recessed portion, the annular member has a protruding portion protruding toward the welding portion at the inner peripheral end portion, and the protruding portion has an inner tapered portion that is inclined toward the welding portion as going from the outer side toward the inner side in the radial direction.

According to this configuration, the annular member has the convex portion at the inner peripheral end portion thereof, and the convex portion has the inner tapered portion.

The inner cone portion is formed to incline toward the joint portion from the radially outer side toward the radially inner side.

Therefore, chips generated at the time of joining the joined members can be guided to the outside in the radial direction (i.e., the outer peripheral end portion of the annular member) by the inner tapered portion. This enables the pressing force generated by the chips to be efficiently applied to the outer tapered portion of the outer peripheral end portion.

The pressing force generated by the chips is divided into a first component force pressing the outer peripheral end portion toward the opposite side of the joint portion and a second component force pressing the outer peripheral end portion toward the inside in the radial direction at the outer tapered portion.

The outer peripheral end of the annular member can be brought into close contact with the recess (i.e., the shoulder member) by the first component force. Further, the inner peripheral end of the annular member can be brought into close contact with the stirring head by the second component force. Thus, the gap between the pin and the shoulder member can be closed (filled) by the annular member, and the annular member can suppress the intrusion of chips into the gap between the pin and the shoulder member.

Further, by the annular member being in close contact with the shoulder member and the tool bit, heat of the tool bit can be efficiently transmitted to the shoulder member via the annular member during friction stir welding. Thus, the heat removal effect of the stirring head can be improved by the annular member.

According to the aspect of the present invention, it is possible to suppress intrusion of chips generated at the time of friction stir welding of the members to be welded into the gap between the stirring head and the shoulder member.

Drawings

Fig. 1 is a cross-sectional view showing a friction stir welding apparatus according to a first embodiment of the present invention.

Fig. 2 is an enlarged sectional view of section II of fig. 1.

Fig. 3 is a perspective view showing a ring member provided in the friction stir welding apparatus according to the first embodiment.

Fig. 4 is a cross-sectional view illustrating an example of friction stir welding performed by the friction stir welding apparatus according to the first embodiment.

Fig. 5 is a perspective view showing a ring member according to a second embodiment of the present invention.

Fig. 6 is a cross-sectional view showing a friction stir welding apparatus including a ring-shaped member according to a second embodiment.

Fig. 7 is a cross-sectional view illustrating an example of friction stir welding performed by the friction stir welding apparatus according to the second embodiment.

Fig. 8 is a sectional view showing a friction stir welding apparatus according to a third embodiment of the present invention.

Fig. 9 is an enlarged sectional view of part IX of fig. 8.

Fig. 10 is a cross-sectional view illustrating an example of friction stir welding performed by the friction stir welding apparatus according to the third embodiment.

Fig. 11 is a cross-sectional view showing a friction stir welding apparatus including a ring member according to a fourth embodiment.

Fig. 12 is a cross-sectional view illustrating an example of friction stir welding performed by the friction stir welding apparatus according to the fourth embodiment.

Detailed Description

Hereinafter, a Friction Stir Welding device (FSW) according to an embodiment of the present invention will be described with reference to the drawings.

(first embodiment)

As shown in fig. 1, the friction stir welding apparatus 10 includes a support jig 12, a friction stir welding tool 14, an annular member 16, a shoulder member 18, and a drive mechanism (not shown).

In the supporting jig 12, a first workpiece (joined member) 21 and a second workpiece (joined member) 22 are arranged (placed) in a stacked state. A hollow cylindrical recess (not shown) may be provided in the support jig 12 at a central portion 12a of the surface of the support jig 12 on which the first workpiece 21 is disposed (i.e., a portion corresponding to a stirring head 26 described later).

For example, a 5000 series aluminum alloy having a number of JIS symbol No. 5000 is used as the first workpiece 21 and the second workpiece 22.

The first workpiece 21 and the second workpiece 22 are joined to each other at the joint portion 23 by the friction stir welding tool 14 in a state of being stacked on the supporting jig 12.

In the first embodiment, an example in which two pieces of the first workpiece 21 and the second workpiece 22 are stacked and the joint 23 is friction stir welded is described, but for example, 3 pieces or more of the workpieces may be stacked and the joint may be friction stir welded. In the first embodiment, an example in which two first works 21 and two second works 22 are stacked and friction stir welded is described, but the first work 21 and the second work 22 may be friction stir welded in a state in which they are butted against each other.

In the first embodiment, the friction stir welding apparatus 10 is described as being of a fixed type as an example, but the present invention is not limited to this, and the friction stir welding apparatus 10 may be provided in an arm of a multi-axis robot or the like disposed in a production line, for example.

The friction stir welding tool 14 includes a shaft portion 25 and a stirring head 26. The shaft portion 25 is formed in a cylindrical shape and is connected to a driving mechanism not shown. Further, at the tip of the shaft portion 25 on the joint portion 23 side, the stirring head 26 is provided coaxially with respect to the rotation shaft 28 of the shaft portion 25.

The stirring head 26 is formed in a cylindrical shape having a smaller diameter than the shaft 25. The stirring head 26 is formed of, for example, steel, stainless steel, aluminum alloy, copper alloy, nickel alloy, tungsten alloy, cobalt alloy, titanium alloy, cemented carbide, ceramic, heat-resistant resin, or the like.

Hereinafter, the axial direction with respect to the rotary shaft 28 may be simply referred to as "axial direction". In addition, the radial direction with respect to the rotation shaft 28 of the stirring head 26 may be simply referred to as "radial direction", and the circumferential direction with respect to the rotation shaft 28 of the stirring head 26 may be simply referred to as "circumferential direction".

As shown in fig. 1 and 2, a groove (recess) 31 is formed in the outer peripheral surface (outer periphery) 26a of the stirring tip 26. The groove 31 is formed as an annular recess along the circumferential direction of the stirring tip 26 at substantially the center in the axial direction of the stirring tip 26. The groove 31 may be formed at an arbitrary position in the axial direction in the inner circumferential surface 18a of the shoulder member 18.

Specifically, the groove 31 has a groove bottom surface 32, a first groove side surface 33, and a second groove side surface 34. The groove bottom surface 32 is formed circumferentially along the outer peripheral surface 26a of the stirring head 26 with a predetermined distance radially inward from the outer peripheral surface 26 a. The first groove side surface 33 is formed in a ring shape radially outward from the outer peripheral surface 26a from the periphery of the groove bottom surface 32 on the side opposite to the joining portion 23 (i.e., the first and second workpieces 21, 22) in the axial direction (the side away from the joining portion 23). The second groove side surface 34 is formed in a ring shape radially outward from the outer peripheral surface 26a to the periphery of the groove bottom surface 32 on the side of the joining portion 23 in the axial direction (the side close to the joining portion 23).

The first groove side surface 33 and the second groove side surface 34 are formed to face each other with a predetermined gap therebetween in the axial direction. That is, the groove 31 is formed in a U-shaped cross section by the groove bottom surface 32, the first groove side surface 33, and the second groove side surface 34.

As shown in fig. 1 to 3, the groove 31 is fitted with the annular member 16. The groove portion 31 is formed such that at least a part of the inner peripheral end portion 35 of the annular member 16 enters the groove portion 31. Therefore, the protruding portion (outer portion) 48 of the annular member 16 protrudes radially outward from the groove portion 31 and is disposed in the gap S between the pin 26 and the shoulder member 18. The outer peripheral end 36 is included in the protrusion 48. The gap S between the pin 26 and the shoulder member 18 is closed by the protrusion 48 of the annular member 16.

The annular member 16 is formed in an annular shape, and is divided in the radial direction to form slits (divided portions) 38. The slit 38 is formed in a crank shape in a side view, for example. In the first embodiment, the example in which the slit 38 is formed in a crank shape is described, but the slit 38 may be formed in other shapes such as a straight line. In the first embodiment, the example in which 1 slit 38 is formed in the annular member 16 is described, but a plurality of slits 38 may be formed in the annular member 16.

The ring member 16 is formed of, for example, steel, stainless steel, aluminum alloy, copper alloy, nickel alloy, tungsten alloy, cobalt alloy, titanium alloy, cemented carbide, ceramic, heat-resistant resin, or the like.

Specifically, the annular member 16 has a first annular surface 41, a second annular surface 42, an annular inner peripheral surface 43, an annular outer peripheral surface 44, an inner tapered portion 45, and an outer tapered portion 46.

The first annular surface 41 is formed on the opposite side (the first groove side surface 33 side) from the engagement portion 23 in the axial direction, and is formed in an annular shape from the annular inner peripheral surface 43 to the annular outer peripheral surface 44 toward the outside in the radial direction. The second annular surface 42 is formed on the joint portion 23 side (second groove side surface 34 side) in the axial direction, and is formed in an annular shape from the inner tapered portion 45 to the outer tapered portion 46 toward the outside in the radial direction.

The annular inner peripheral surface 43 axially connects the inner periphery of the first annular surface 41 and the inner periphery of the inner tapered portion 45, and is formed circumferentially along the groove bottom surface 32, for example, at a predetermined distance radially outward from the groove bottom surface 32. The annular outer peripheral surface 44 axially connects the outer periphery of the first annular surface 41 with the vicinity of the outer periphery of the outer tapered portion 46. The annular outer peripheral surface 44 is formed circumferentially at a predetermined distance radially inward from an inner peripheral surface 18a (described later) of the shoulder member 18, for example.

The inner tapered portion 45 is formed at a portion of the inner peripheral end portion 35 of the annular member 16 on the joint portion 23 side. Specifically, the inner tapered portion 45 is a surface inclined in the axial direction from the periphery of the annular inner peripheral surface 43 on the joint portion 23 side (the side close to the joint portion 23) to the inner periphery of the second annular surface 42 so as to approach the joint portion 23 from the radially inner side toward the radially outer side.

The inner tapered portion 45 and the inner peripheral end portion 35 are integrally fitted (accommodated) in the groove portion 31 in the first embodiment. The inner tapered portion 45 and the inner peripheral end portion 35 may be partially fitted in the groove portion 31.

The annular member 16 has a projection 37 projecting toward the joint portion 23 at an outer peripheral end 36 thereof. The convex portion 37 has an outer tapered portion 46. Specifically, the outer tapered portion 46 is a surface that is inclined so as to approach the engagement portion 23 from the outer periphery of the second annular surface 42 to the periphery of the annular outer peripheral surface 44 on the engagement portion 23 side (the side close to the engagement portion 23) in the axial direction, as going from the radially inner side to the outer side.

As shown in fig. 1, the pin 26 is surrounded on the outer circumferential surface 26a in the circumferential direction by the shoulder member 18 on the radially outer side. The shoulder member 18 is formed of, for example, steel, stainless steel, aluminum alloy, copper alloy, nickel alloy, tungsten alloy, cobalt alloy, titanium alloy, cemented carbide, ceramic, heat-resistant resin, or the like. The pin 26, the shoulder member 18, and the ring member 16 may not be made of the same material.

The shoulder member 18 is, for example, a cylindrical member formed with a through hole 51 penetrating in the axial direction. The shoulder member 18 has an inner peripheral surface (inner periphery) 18a and a stepped portion 52. The inner peripheral surface 18a is formed circumferentially along the outer peripheral surface 26a of the stirring head 26 at a predetermined interval radially outward of the outer peripheral surface 26a of the stirring head 26. In other words, the inner circumferential surface 18a is formed to surround the pin 26 on the outer side on the surface intersecting the rotation shaft 28 of the pin 26.

That is, a slight gap S is formed between the outer peripheral surface 26a of the pin 26 and the inner peripheral surface 18a of the shoulder member 18, for example, in the radial direction. The stirring head 26 is inserted through the through hole 51 of the shoulder member 18 so as to be movable in the axial direction.

The stepped portion 52 is formed in a ring shape so as to protrude radially outward from the inner peripheral surface 18a at an end portion 18b of the shoulder member 18 on the side of the joint portion 23 and so as to be recessed toward the opposite side of the joint portion 23.

The shoulder member 18 is coupled to a drive mechanism, not shown, in the same manner as the shaft portion 25. The drive mechanism is capable of moving the pin 26 in the axial direction with respect to the shoulder member 18 in a state where the pin 26 is inserted through the through hole 51 of the shoulder member 18. The drive mechanism can rotate the pin 26 in the circumferential direction about the rotation shaft 28, and can rotate the shoulder member 18 in accordance with the rotation of the pin 26.

The clearance S between the outer peripheral surface 26a of the pin 26 and the inner peripheral surface 18a of the shoulder member 18 is set so that the pin 26 can be stably held by the shoulder member 18 in a state where the pin 26 is rotated about the rotation shaft 28.

Next, an example of suppressing intrusion of chips (for example, burrs) generated when friction stir welding is performed by the friction stir welding apparatus 10 according to the first embodiment into the gap S between the tool bit 26 and the shoulder member 18 will be described with reference to fig. 1, 2, and 4.

As shown in fig. 1, the joint portion 23 is disposed on the supporting jig 12 in a state where the first workpiece 21 and the second workpiece 22 are stacked. In this state, the joint portion 23 is located at a position corresponding to the pin 26 and the shoulder member 18. The end 26b of the pin 26 is disposed substantially coplanar with the end 18b of the shoulder member 18.

Next, the drive mechanism is operated to lower the stirring head 26 and the shoulder member 18, so that the end portion 18b of the shoulder member 18 approaches the joint portion 23 by a predetermined distance, and the stirring head 26 and the shoulder member 18 are rotated along the rotation axis 28 in the direction of the arrow a. Next, the pin 26 and the shoulder member 18 are further moved toward the joint portion 23, for example, the end portion 18b of the shoulder member 18 is brought into sliding contact with the joint portion 23. The joint portion 23 is pressed by the end portion 18b of the shoulder member 18, and the joint portion 23 is softened by frictional heat.

Next, the end 26b of the stirring head 26 is projected from the end 18b of the shoulder member 18 to the joint 23 side and is brought into sliding contact with the joint 23 while pressing the joint 23. Frictional heat is generated at the joint portion 23 with which the end portion 26b of the stirring head 26 is in sliding contact. Therefore, the joint portion 23 is softened and the stirring head 26 is embedded in the joint portion 23. Thereby, the second workpiece 22 and the first workpiece 21 are friction stir welded at the welding portion 23 by the friction stir welding apparatus 10.

Here, according to the friction stir welding apparatus 10, as shown in fig. 1 and 2, the groove portion 31 of the stirring head 26 is fitted with the inner peripheral end portion 35 of the annular member 16. Therefore, the protruding portion 48 of the annular member 16 protrudes radially outward from the groove portion 31 and is disposed in the gap S between the pin 26 and the shoulder member 18.

This can suppress the intrusion of chips, which are generated when the first workpiece 21 and the second workpiece 22 are friction stir welded at the joint 23, into the gap S between the tool bit 26 and the shoulder member 18 by the annular member 16. Therefore, the quality of the friction stir welding of the joint portion 23 of the first workpiece 21 and the second workpiece 22 can be improved.

Further, by fitting the inner peripheral end portion 35 of the annular member 16 into the groove portion 31, heat transferred to the pin 26 during friction stir welding can be transferred (dissipated) to the shoulder member 18 via the annular member 16. This can expect the heat removing effect of the stirring head 26.

Further, according to the friction stir welding apparatus 10, as shown in fig. 1 and 4, the inner tapered portion 45 is disposed in a state of being inserted into the groove portion 31. The inner tapered portion 45 is inclined so as to approach the joint portion 23 from the radially inner side toward the radially outer side. Therefore, chips generated when the joint portion 23 is friction stir welded enter the groove portion 31 as shown by arrows B and C, and the pressing force generated by the chips can be applied to the inner tapered portion 45.

The pressing force generated by the chips is divided at the inner taper portion 45 into a first component force F1 that presses the inner peripheral end portion 35 of the annular member 16 toward the side opposite to the joint portion 23, and a second component force F2 that presses the inner peripheral end portion 35 of the annular member 16 toward the outside in the radial direction.

Therefore, the inner peripheral end 35 of the annular member 16 can be brought into close contact with the first tank side surface 33 (i.e., the stirring head 26) of the tank 31 by the first component force F1. Further, the annular member 16 can be expanded in diameter by the second component force F2, and the outer peripheral end 36 can be brought into close contact with the inner peripheral surface 18a of the shoulder member 18.

Further, in the inner taper 45, a force F3 directed radially outward acts by the centrifugal force of the chips entering the groove portion 31 in addition to the second component force F2. Therefore, the outer peripheral end 36 of the annular member 16 is more closely attached to the inner peripheral surface 18a of the shoulder member 18. This enables the annular member 16 to favorably close (fill) the gap S between the pin 26 and the shoulder member 18, and the annular member 16 to more favorably suppress the intrusion of chips into the gap S.

Further, the inner tapered portion 45 is disposed so as to enter the groove portion 31, and the outer peripheral end portion 36 of the annular member 16 is brought into close contact with the inner peripheral surface 18a of the shoulder member 18, whereby the annular member 16 can be brought into close contact with the pin 26 and the shoulder member 18. Therefore, the heat transferred from the pin at the time of friction stir welding can be efficiently transferred to the shoulder member 18 via the annular member 16. This can improve the heat removal effect of the stirring head 26 by the annular member 16.

In addition, according to the friction stir welding apparatus 10, the inner tapered portion 45 is disposed in the groove portion 31, and the outer tapered portion 46 is formed in the convex portion 37 of the annular member 16.

The outer tapered portion 46 is inclined so as to approach the joint portion 23 from the radially inner side toward the radially outer side. Therefore, the chips generated at the time of friction stir welding the joint portion 23 can be efficiently guided radially inward (i.e., toward the inner peripheral end portion 35 of the annular member 16) by the outer tapered portion 46 as indicated by the arrow B. This enables the pressing force generated by the chips to be efficiently applied to the inner tapered portion 45 of the inner peripheral end portion 35.

As described above, the pressing force generated by the chips is divided into the first component force F1 that presses the inner peripheral end portion 35 toward the side opposite to the joint portion 23 and the second component force F2 that presses the inner peripheral end portion 35 toward the radially outer side in the inner tapered portion 45.

Therefore, the inner peripheral end 35 of the annular member 16 can be brought into close contact with the first tank side surface 33 of the tank 31 (i.e., the stirring head 26) efficiently by the first component force F1. Further, the annular member 16 can be expanded in diameter by the second component force F2, and the outer peripheral end portion 36 can be brought into close contact with the inner peripheral surface 18a of the shoulder member 18 efficiently. This enables the annular member 16 to efficiently close (fill) the gap S between the pin 26 and the shoulder member 18, and enables the annular member 16 to more efficiently suppress the intrusion of chips into the gap S.

The inner tapered portion 45 is disposed so as to enter the groove portion 31, and the outer tapered portion 46 is formed on the convex portion 37 of the annular member 16. Therefore, by bringing the annular member 16 into close contact with the pin 26 and the shoulder member 18 more efficiently, the heat transferred to the pin 26 at the time of friction stir welding can be transferred to the shoulder member 18 via the annular member 16 more efficiently.

This can further improve the heat removal effect of the stirring head 26 by the annular member 16.

In the first embodiment, the slit 38 is formed in the annular member 16, and the annular member 16 is expanded in diameter by the second component force F2 acting on the inner tapered portion 45, and the outer peripheral end portion 36 is brought into close contact with the inner peripheral surface 18a of the shoulder member 18. As another example, for example, as in the first example, the pressing force generated by the chips may be applied to the inner circumferential surface of the annular member 16 to bring the outer circumferential end 36 into close contact with the inner circumferential surface 18a of the shoulder member 18. As in the second example, the annular member 16 may be expanded by frictional heat to bring the outer peripheral end 36 into close contact with the inner peripheral surface 18a of the shoulder member 18. In this case, the slit 38 of the annular member 16 may not be required.

Further, as in the third example, the annular member 16 may be pressed against the first groove side surface 33 of the groove portion 31 by the action of the chips, and the annular member 16 may be compressed in the axial direction by the pressing force of the chips, thereby reducing the thickness of the annular member 16. Thus, the annular member 16 may be expanded radially outward to bring the outer peripheral end 36 into close contact with the inner peripheral surface 18a of the shoulder member 18. In this case, the slit 38 of the annular member 16 may not be required. In addition to this, a plurality of the first embodiment, the first example, and the third example may be applied.

Next, a friction stir welding apparatus according to a second embodiment to a third embodiment of the present invention will be described with reference to fig. 5 to 9. In the second and third embodiments, the same reference numerals are given to the same or similar components as those of the first embodiment, and the description thereof will be omitted, and the description will be made about the differences.

(second embodiment)

As shown in fig. 5 and 6, the friction stir welding apparatus 60 is similar to the friction stir welding apparatus 10 of the first embodiment in other configurations, except that the annular member 16 of the first embodiment is replaced with an annular member 62.

The friction stir welding apparatus 60 has a groove 31 formed in the stir head 26, and a part of the annular member 62 is fitted into the groove 31. Therefore, the protruding portion (outer portion) 63 of the annular member 62 protrudes radially outward from the groove portion 31 and is disposed in the gap S between the pin 26 and the shoulder member 18.

The annular member 62 is formed in an annular shape, and is divided in the radial direction to form slits (divided portions) 64. The slit 64 is formed in a substantially crank shape in a side view, for example. In the second embodiment, an example in which 1 slit 64 is formed in the annular member 62 is described, but a plurality of slits 64 may be formed in the annular member 62.

The annular member 62 has a first annular end portion 65 and a second annular end portion 66 that are circumferentially opposed to each other as a pair of end portions by forming a slit 64.

The first annular end portion 65 forms one of the pair of end portions, and has a first slit surface portion 71, a first joint portion 72, and a first enlarged diameter surface portion (first surface portion) 73.

The first slit surface portion 71 is located on the opposite side of the first annular end portion 65 from the joint portion 23 (see fig. 1) in the axial direction, and is arranged along the axial direction at the circumferential end portion. The first joint portion 72 is located on the joint portion 23 side of the first annular end portion 65 in the axial direction with respect to the first slit surface portion 71, and extends from the first slit surface portion 71 so as to protrude in the circumferential direction. The first enlarged diameter surface portion 73 is formed at an end portion in the circumferential direction of the first joint portion 72.

The second annular end portion 66 forms the other of the pair of end portions, and has a second slit surface portion 75, a second joining portion 76, and a second enlarged diameter surface portion (second surface portion) 77.

The second slit surface portion 75 is located on the opposite side of the second annular end portion 66 in the axial direction from the joint portion 23 (see fig. 1), and is arranged along the axial direction so as to face the first slit surface portion 71 in the circumferential direction. The second engagement portion 76 is located on the opposite side of the engagement portion 23 in the axial direction, and extends protrudingly in the circumferential direction along the first engagement portion 72. A second slit surface portion 75 is formed at an end portion of the second joint portion 76. The second enlarged diameter surface portion 77 is formed on the joining portion 23 side of the second joining site 76 in the axial direction, and is disposed at a position circumferentially opposed to the first enlarged diameter surface portion 73.

The first joining portion 72 and the second joining portion 76 extend in the circumferential direction and are arranged to overlap in the axial direction. The first joining portion 72 and the second joining portion 76 form the overlapping portion 68.

That is, the first engagement portion 72 is formed at a portion of the axially overlapping portion 68 on the side of the engagement portion 23 (see fig. 1), and extends in the circumferential direction. The second engagement portion 76 forms a portion of the axially overlapping portion 68 on the opposite side from the engagement portion 23, and extends in the circumferential direction along the first engagement portion 72.

The first diameter-increasing surface portion 73 is tapered at the circumferential end of the first joining portion 72 so that the distance from the second diameter-increasing surface portion 77 increases from the portion 72a opposite to the joining portion 23 toward the joining portion 23. The second diameter-enlarged surface portion 77 is tapered so that the interval with the first diameter-enlarged surface portion 73 increases from the end portion 76a on the joint portion 23 side of the second joint portion 76 toward the joint portion 23. That is, the first diameter-enlarging surface portion 73 and the second diameter-enlarging surface portion 77 are inclined so as to form a V-shape that widens in the circumferential direction as they approach the joint portion 23.

Next, an example of suppressing intrusion of chips generated at the time of friction stir welding by the friction stir welding device 60 of the second embodiment into the gap S between the tool bit 26 and the shoulder member 18 will be described with reference to fig. 7.

As shown in fig. 7, according to the friction stir welding apparatus 60, a part of the annular member 62 is fitted into the groove portion 31 of the stir head 26, and the protrusion 63 (see fig. 6) of the annular member 62 is disposed in the gap S between the stir head 26 and the shoulder member 18.

Therefore, chips generated at the time of friction stir welding by the friction stir welding device 60 can enter the first welding site 72 as indicated by arrow D, and a pressing force pressing toward the side opposite to the welding portion 23 can be applied to the first welding site 72. This allows the first joining portion 72 to be pressed against the second joining portion 76, and the overlapping portion 68 to be brought into close contact in the axial direction. Further, the annular member 62 can be brought into close contact with the first groove side surface 33 (i.e., the stirring head 26) of the groove portion 31 by the pressing force of the chips acting on the entire circumference of the annular member 62.

In addition, the first diameter-enlarging surface portion 73 and the second diameter-enlarging surface portion 77 are inclined in a V shape so as to widen in the circumferential direction toward the joint portion 23 (see fig. 1). Therefore, chips generated at the time of friction stir welding can enter the first diameter-enlarged surface portion 73 and the second diameter-enlarged surface portion 77 as indicated by arrow E, and the pressing force generated by the chips can be applied to the first diameter-enlarged surface portion 73 and the second diameter-enlarged surface portion 77.

The pressing force generated by the chips is divided into a first component force F4 pressing toward the side opposite to the joint portion 23 at the first diameter-enlarged surface portion 73 and a second component force F5 pressing so as to widen the interval between the first diameter-enlarged surface portion 73 and the second diameter-enlarged surface portion 77.

The pressing force generated by the chips is divided into a first component force F6 pressing toward the side opposite to the joint portion 23 and a second component force F7 pressing to widen the interval between the first diameter-enlarged surface portion 73 and the second diameter-enlarged surface portion 77 at the second diameter-enlarged surface portion 77.

That is, the second component force F5, F7 can expand the diameter of the annular member 62 and bring the outer peripheral surface 62a of the annular member 62 into close contact with the inner peripheral surface 18a of the shoulder member 18.

In this way, the overlapping portion 68 can be brought into close contact with the groove 31 (i.e., the stirring head 26) by the pressing force of the chips. In addition, the annular member 62 can be expanded in diameter by the second component forces F5 and F7, and the outer peripheral surface 62a can be brought into close contact with the inner peripheral surface 18a of the shoulder member 18. Thereby, the gap S between the pin 26 and the shoulder member 18 can be closed (filled) by the annular member 62, and the annular member 62 can suppress the intrusion of chips into the gap S.

Here, by inclining the first diameter-enlarged surface portion 73, the first diameter-enlarged surface portion 73 can be pressed toward the side opposite to the joint portion 23 (see fig. 1) by the first component force F4. Therefore, the first joining site 72 can be pressed against the second joining site 76 by the first component force F4, and the overlapping portion 68 can be brought into close contact with each other more reliably.

Further, by inclining the first diameter-enlarged surface portion 73 and the second diameter-enlarged surface portion 77, the first diameter-enlarged surface portion 73 can be pressed toward the side opposite to the joint portion 23 by the first component force F4, and the second diameter-enlarged surface portion 77 can be pressed toward the side opposite to the joint portion 23 by the first component force F6. Therefore, the vicinity of the slit 64 in the annular member 62 can be brought into close contact with the first tank side surface 33 of the tank 31 (i.e., the stirring head 26).

This can more reliably suppress the intrusion of chips into the gap S between the pin 26 and the shoulder member 18 by the annular member 62.

Further, by bringing the annular member 62 into close contact with the pin 26 and the shoulder member 18, the heat of the pin 26 can be efficiently transmitted to the shoulder member 18 via the annular member 62 during friction stir welding. This can improve the heat removal effect of the stirring head 26 by the annular member 62.

In the second embodiment, the first diameter-expanding surface portion 73 and the second diameter-expanding surface portion 77 are both inclined in a tapered shape, but the present invention is not limited thereto. As another example, either one of the first diameter-enlarging surface portion 73 and the second diameter-enlarging surface portion 77 may be inclined in a tapered shape.

Further, the shape of the annular member 62 of the second embodiment may be combined with the shape of the annular member 16 of the first embodiment. That is, the inner tapered portion 45 and the outer tapered portion 46 (both, see fig. 2) of the annular member 16 of the first embodiment may be added to the shape of the annular member 62 of the second embodiment.

This can more reliably and efficiently suppress the intrusion of chips into the gap S between the pin 26 and the shoulder member 18 by the annular member 62.

Moreover, the heat of the pin 26 can be more reliably and efficiently transferred to the shoulder member 18 via the annular member 62 during friction stir welding, and the heat removal effect of the pin 26 can be further improved.

(third embodiment)

As shown in fig. 8 and 9, the friction stir welding apparatus 100 has a groove portion (recess portion) 102 formed in the inner peripheral surface 18a of the shoulder member 18, and the annular member 104 is fitted into the groove portion 102, and the other configuration is the same as that of the friction stir welding apparatus 10 according to the first embodiment.

The groove portion 102 is formed as an annular recess along the circumferential direction of the inner peripheral surface 18a in the vicinity of the end portion 18b in the inner peripheral surface 18a of the shoulder member 18. The groove 102 may be formed at an arbitrary position in the axial direction in the inner circumferential surface 18a of the shoulder member 18. Specifically, the groove 102 has a groove bottom surface 106, a first groove side surface 107, and a second groove side surface 108.

The groove bottom surface 106 is formed circumferentially along the inner peripheral surface 18a of the shoulder member 18 at a predetermined distance radially outward from the inner peripheral surface 18 a. The first groove side surface 107 is formed in a ring shape radially inward from the periphery of the groove bottom surface 106 on the side opposite to the joint portion 23 (i.e., the first workpiece 21 and the second workpiece 22) in the axial direction (the side away from the joint portion 23) to the inner peripheral surface 18 a. The second groove side surface 108 is formed in a ring shape radially inward from the periphery of the groove bottom surface 106 on the side of the joint portion 23 in the axial direction (on the side close to the joint portion 23) to the inner peripheral surface 18 a.

The first groove side surface 107 and the second groove side surface 108 are formed to face each other with a predetermined gap therebetween in the axial direction. That is, the groove 102 is formed in a U-shaped cross section by the groove bottom surface 106, the first groove side surface 107, and the second groove side surface 108.

An annular member 104 is fitted in the groove 102. The groove 102 is formed such that at least a part of the outer peripheral end 112 of the annular member 104 enters the groove 102. Therefore, the protruding portion (inner portion) 116 of the annular member 104 protrudes radially inward from the groove portion 102, and is disposed in the gap S between the outer peripheral surface 26a of the stirring head 26 and the inner peripheral surface 18a of the shoulder member 18. The protruding portion 116 includes an inner peripheral end portion 113. The gap S between the pin 26 and the shoulder member 18 is closed by the protrusion 116 of the annular member 104.

The annular member 104 has a first annular surface 121, a second annular surface 122, an annular inner peripheral surface 123, an annular outer peripheral surface 124, an outer tapered portion 125, and an inner tapered portion 126.

The first annular surface 121 is formed on the opposite side (the first groove side surface 107 side) from the engagement portion 23 in the axial direction, and is formed in an annular shape from the annular inner peripheral surface 123 to the annular outer peripheral surface 124 toward the outside in the radial direction. The second annular surface 122 is formed on the joint portion 23 side (second groove side surface 108 side) in the axial direction, and is formed annularly from the inner tapered portion 126 to the outer tapered portion 125 toward the outside in the radial direction.

The annular inner peripheral surface 123 axially connects an inner periphery of the first annular surface 121 and an inner periphery vicinity of the inner tapered portion 126. The annular inner circumferential surface 123 is formed circumferentially at a predetermined distance radially outward from the outer circumferential surface 26a of the stirring head 26, for example. The annular outer peripheral surface 124 axially connects the outer periphery of the first annular surface 121 and the outer periphery of the outer tapered portion 125. The annular outer peripheral surface 124 is formed circumferentially along the groove bottom surface 106, for example, at a predetermined distance radially inward of the groove bottom surface 106.

The outer tapered portion 125 is formed at a portion of the outer peripheral end portion 112 of the annular member 104 on the joint portion 23 side. Specifically, the outer tapered portion 125 is a surface that is inclined from the periphery of the annular outer peripheral surface 124 on the side of the joint portion 23 (the side close to the joint portion 23) to the outer periphery of the second annular surface 122 in the axial direction so as to approach the joint portion 23 as going from the outer side to the inner side in the radial direction.

The outer tapered portion 125 and the outer peripheral end portion 112 are integrally fitted (accommodated) in the groove portion 102 in the third embodiment. The outer tapered portion 125 and the outer peripheral end portion 112 may be partially fitted in the groove portion 102.

The annular member 104 has a convex portion 114 protruding toward the joint portion 23 at an inner peripheral end portion 113.

The convex portion 114 has an inner tapered portion 126. Specifically, the inner tapered portion 126 is a surface inclined so as to approach the joint portion 23 from the inner periphery of the second annular surface 122 to the periphery of the annular inner peripheral surface 123 on the joint portion 23 side (the side close to the joint portion 23) in the axial direction, as going from the radially outer side to the radially inner side.

Next, an example of suppressing intrusion of chips generated at the time of friction stir welding by the friction stir welding apparatus 100 of the third embodiment into the gap S between the tool bit 26 and the shoulder member 18 will be described based on fig. 8 to 10.

As shown in fig. 8 and 9, according to the friction stir welding apparatus 100, the outer peripheral end 112 of the annular member 104 is fitted into the groove 102 of the inner peripheral surface 18a of the shoulder member 18. Therefore, the protruding portion 116 of the annular member 104 protrudes radially inward from the groove portion 102, and is disposed in the gap S between the pin 26 and the shoulder member 18.

This can suppress the intrusion of chips, which are generated when the first workpiece 21 and the second workpiece 22 are friction stir welded at the joint 23, into the gap S between the tool bit 26 and the shoulder member 18 by the annular member 104. Therefore, the quality of the friction stir welding of the joint portion 23 of the first workpiece 21 and the second workpiece 22 can be improved.

Further, by fitting the outer peripheral end 112 of the annular member 104 into the groove 102, heat transferred to the stirring head 26 at the time of friction stir welding can be transferred (dissipated) to the shoulder member 18 via the annular member 104. This can expect the heat removing effect of the stirring head 26.

Further, according to the friction stir welding apparatus 100, as shown in fig. 8 and 10, the outer tapered portion 125 is disposed in a state of entering the groove portion 102. The outer tapered portion 125 is inclined so as to approach the joint portion 23 from the radially outer side toward the radially inner side. Therefore, chips generated when the joint portion 23 is friction stir welded enter the groove portion 102 as shown by arrows F and G, and the pressing force generated by the chips can be applied to the outer tapered portion 125.

The pressing force generated by the chips is divided into a first partial force F8 that presses the outer peripheral end portion 112 of the annular member 104 toward the side opposite to the joint portion 23 and a second partial force F9 that presses the outer peripheral end portion 112 of the annular member 16 toward the inside in the radial direction at the outer side tapered portion 125.

Therefore, the outer peripheral end 112 of the annular member 104 can be brought into close contact with the first groove side surface 107 (i.e., the shoulder member 18) of the groove portion 102 by the first component force F8. Further, the second component force F9 reduces the diameter of the annular member 104, and the inner peripheral end portion 113 can be brought into close contact with the outer peripheral surface 26a of the stirring tip 26.

In addition to the second component force F9, the outer taper portion 125 is also acted upon by a radially inward force F10 by the centrifugal force of the chips entering the groove portion 102. Therefore, the inner peripheral end 113 of the annular member 104 is more closely attached to the outer peripheral surface 26a of the stirring head 26. This enables the annular member 16 to favorably close (fill) the gap S between the pin 26 and the shoulder member 18, and the annular member 104 to more favorably suppress the intrusion of chips into the gap S.

Further, the annular member 104 can be brought into close contact with the pin 26 and the shoulder member 18 by placing the outer tapered portion 125 in a state of entering the groove portion 102 and bringing the inner peripheral end portion 113 of the annular member 104 into close contact with the outer peripheral surface 26a of the pin 26. Therefore, the heat transferred from the pin at the time of friction stir welding can be efficiently transferred to the shoulder member 18 via the annular member 104. This can improve the heat removal effect of the stirring head 26 by the annular member 104.

In addition, according to the friction stir welding apparatus 100, the outer tapered portion 125 is disposed in a state of being inserted into the groove portion 102, and the inner tapered portion 126 is formed in the convex portion 114 of the annular member 104. The inner tapered portion 126 is inclined so as to approach the joint portion 23 from the radially outer side toward the radially inner side. Therefore, the chips generated at the time of friction stir welding of the joint portion 23 can be efficiently guided to the outside in the radial direction (i.e., the outer peripheral end portion 112 side of the annular member 104) as indicated by the arrow F by the inner tapered portion 126. This enables the pressing force generated by the chips to be efficiently applied to the outer tapered portion 125 of the outer peripheral end portion 112.

As described above, the pressing force generated by the chips is divided into the first partial force F8 that presses the outer peripheral end portion 112 toward the side opposite to the joint portion 23 and the second partial force F9 that presses the outer peripheral end portion 112 radially inward in the outer tapered portion 125.

Therefore, the outer peripheral end 112 of the annular member 104 can be brought into close contact with the first groove side surface 107 (i.e., the shoulder member 18) of the groove portion 102 efficiently by the first component force F8. Further, the second component force F9 reduces the diameter of the annular member 104, and the inner peripheral end portion 113 can be brought into close contact with the outer peripheral surface 26a of the stirring tip 26 efficiently. This enables the annular member 104 to efficiently close (fill) the gap S between the pin 26 and the shoulder member 18, and enables the annular member 104 to more efficiently suppress the intrusion of chips into the gap S.

The outer tapered portion 125 is disposed so as to enter the groove portion 102, and an inner tapered portion 126 is formed on the convex portion 114 of the annular member 104. Therefore, the annular member 104 is more efficiently in close contact with the pin 26 and the shoulder member 18, and thus the heat transferred to the pin 26 at the time of friction stir welding can be more efficiently transferred to the shoulder member 18 via the annular member 104. This can further improve the heat removal effect of the stirring head 26 by the annular member 104.

In the third embodiment, the example in which the slit is formed in the annular member 104, the annular member 104 is reduced in diameter by the second component force F9 acting on the outer tapered portion 125, and the inner peripheral end portion 113 is brought into close contact with the outer peripheral surface 26a of the stirring tip 26 has been described, but the present invention is not limited to this. As another example, for example, as in the first example, the pressing force generated by the chips may be applied to the outer peripheral surface of the annular member 104 to bring the inner peripheral end portion 113 into close contact with the outer peripheral surface 26a of the stirring head 26. As in the second example, the annular member 16 may be expanded radially inward by frictional heat to bring the outer peripheral end 36 into close contact with the outer peripheral surface 26a of the stirring head 26. In this case, the slit of the annular member 104 may not be necessary.

Further, as in the third example, the thickness of the annular member 104 may be reduced by pressing the annular member 104 against the first groove side surface 107 of the groove 102 by the action of the chips, and compressing the annular member 104 in the axial direction by the pressing force of the chips. Thus, the inner peripheral end 113 may be brought into close contact with the outer peripheral surface 26a of the stirring head 26 by expanding the annular member 104 radially inward. In this case, the slit of the annular member 104 may not be necessary. In addition, a plurality of the third embodiment and the first to third examples may be applied.

(fourth embodiment)

As shown in fig. 11, the friction stir welding apparatus 140 has a groove 102 formed in the inner peripheral surface 18a of the shoulder member 18, and an annular member 142 fitted in the groove 102, and has the same other configuration as the friction stir welding apparatus 60 according to the second embodiment.

The annular member 142 is fitted into the groove 102 of the shoulder member 18, and at least a part of the outer peripheral end 143 is formed so as to enter the annular member 142. Therefore, the protruding portion (inner portion) 144 of the annular member 142 protrudes radially inward from the groove portion 102 and is disposed in the gap S between the outer peripheral surface 26a of the stirring head 26 and the inner peripheral surface 18a of the shoulder member 18. The protruding portion 144 includes an inner peripheral end 145. The gap S between the pin 26 and the shoulder member 18 is closed by the protruding portion 144 of the annular member 142.

The annular member 142 is formed in an annular shape, and is divided in the radial direction to form slits (divided portions) 146. The slit 146 is formed in a substantially crank shape in a side view, for example. In the fourth embodiment, an example in which 1 slit 146 is formed in the annular member 142 is described, but a plurality of slits 146 may be formed in the annular member 142.

The annular member 142 has a first annular end 151 and a second annular end 152 that are circumferentially opposed to each other as a pair of ends by forming the slit 146.

The first annular end portion 151 forms one of a pair of end portions, and has a first joining portion 154 and a first diameter-expanding recess portion 155.

The first engagement portion 154 is located on the side of the engagement portion 23 (see fig. 1) in the axial direction in the first annular end portion 151, and extends so as to protrude in the circumferential direction. The first diameter-expanding recessed portion 155 is located on the opposite side of the first engagement portion 154 from the base end 154a of the first engagement portion 154 in the circumferential direction, and is recessed in the axial direction from the engagement portion 23 side to the opposite side to the engagement portion 23.

The first diameter-expanding recess 155 has a first diameter-expanding surface portion (first surface portion) 156 on the first joining site 154 side in the circumferential direction. The first diameter-enlarged surface portion 156 is formed in a tapered shape so as to approach the joint portion 23 as it goes toward the first joint portion 154 in the circumferential direction.

The second annular end portion 152 forms the other of the pair of end portions, and has a second engagement portion 158 and a second diameter-expanding recess 159.

The second engagement portion 158 is located on the opposite side of the engagement portion 23 in the axial direction and extends protrudingly in the circumferential direction along the first engagement portion 154. The second diameter-expanding concave portion 159 is located on the opposite side of the second engagement portion 158 from the base end 158a of the second engagement portion 158 in the circumferential direction, and is formed concavely from the engagement portion 23 side to the opposite side of the engagement portion 23 in the axial direction.

The second diameter-expanding recess 159 has a second diameter-expanding surface portion (second surface portion) 161 on the second joining portion 158 side in the circumferential direction. The second enlarged diameter surface portion 161 is formed in a tapered shape so as to approach the joint portion 23 as it goes toward the second joint portion 158 in the circumferential direction.

The first joint portion 154 and the second joint portion 158 extend in the circumferential direction and are arranged to overlap in the axial direction. The first joining portion 154 and the second joining portion 158 form an overlapping portion 153.

That is, the first engagement portion 154 is formed at a portion of the overlap portion 153 on the side of the engagement portion 23 (see fig. 1) in the axial direction, and extends in the circumferential direction. The second engagement portion 158 forms a portion of the axially overlapping portion 153 on the opposite side from the engagement portion 23, and extends in the circumferential direction along the first engagement portion 154.

The first diameter-expanding surface portion 156 and the second diameter-expanding surface portion 161 are inclined so that the interval therebetween in the circumferential direction decreases toward the first joining portion 154.

Next, an example of suppressing intrusion of chips generated at the time of friction stir welding by the friction stir welding device 140 of the fourth embodiment into the gap S between the tool bit 26 and the shoulder member 18 will be described with reference to fig. 12.

As shown in fig. 12, chips generated during friction stir welding intrude into the first joint portion 154 as indicated by an arrow H, and a pressing force pressing the first joint portion 154 toward the side opposite to the joint portion 23 is applied. This allows the first joining portion 154 to be pressed against the second joining portion 158, and the overlapping portions 153 to be brought into close contact in the axial direction. Further, the annular member 142 can be brought into close contact with the first groove side surface 107 (i.e., the shoulder member 18) of the groove portion 102 by the pressing force of the chips acting on the entire circumference of the annular member 142.

In addition, chips generated during friction stir welding can enter the first diameter-enlarging surface portion 156 and the second diameter-enlarging surface portion 161 as indicated by the arrow I, and the pressing force generated by the chips can be applied to the first diameter-enlarging surface portion 156 and the second diameter-enlarging surface portion 161. The pressing force generated by the chips is divided into a first component force F11 pressing toward the side opposite to the joint portion 23 and a second component force F12 pressing so that the interval between the first diameter-enlarged surface portion 156 and the second diameter-enlarged surface portion 161 becomes narrower in the first diameter-enlarged surface portion 156 and the second diameter-enlarged surface portion 161.

That is, the second component force F12 can reduce the diameter of the annular member 142, and the inner peripheral end 145 of the annular member 142 (specifically, the inner peripheral surface 145a of the inner peripheral end 145) can be brought into close contact with the outer peripheral surface 26a of the mixing head 26. Thereby, the gap S between the pin 26 and the shoulder member 18 can be closed (filled) by the annular member 142, and the intrusion of chips into the gap S can be suppressed by the annular member 62.

Here, the first diameter-enlarged surface portion 156 can be pressed toward the side opposite to the joint portion 23 (see fig. 1) by the first component force F11. Therefore, the first joining portion 154 can be pressed against the second joining portion 158 by the first component force F11, and the overlapping portion 153 can be brought into close contact with each other more reliably.

Then, the first diameter-enlarged surface portion 156 and the second diameter-enlarged surface portion 161 can be pressed toward the side opposite to the joint portion 23 by the first component force F11. Therefore, the vicinity of the slit 146 in the annular member 142 can be brought into close contact with the first groove side surface 107 (i.e., the shoulder member 18) of the groove portion 102.

This can more reliably suppress the intrusion of chips into the gap S between the pin 26 and the shoulder member 18 by the annular member 142.

Further, by bringing the annular member 142 into close contact with the pin 26 and the shoulder member 18, the heat of the pin 26 can be efficiently transmitted to the shoulder member 18 via the annular member 142 during friction stir welding. This can improve the heat removal effect of the stirring head 26 by the annular member 62.

In the fourth embodiment, the example in which both the first diameter-enlarging surface portion 156 and the second diameter-enlarging surface portion 161 are inclined in the tapered shape has been described, but the present invention is not limited to this. As another example, either one of the first diameter-enlarging surface portion 156 and the second diameter-enlarging surface portion 161 may be inclined in a tapered shape.

The shape of the annular member 142 of the fourth embodiment may be combined with the shape of the annular member 104 of the third embodiment. That is, the outer tapered portion 125 and the inner tapered portion 126 (both see fig. 9) of the annular member 104 according to the third embodiment may be added to the shape of the annular member 142 according to the fourth embodiment. This can more reliably and efficiently suppress the intrusion of chips into the gap S between the pin 26 and the shoulder member 18 by the annular member 62.

Moreover, the heat of the pin 26 can be more reliably and efficiently transferred to the shoulder member 18 via the annular member 142 during friction stir welding, and the heat removal effect of the pin 26 can be further improved.

The technical scope of the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the present invention.

For example, the friction stir welding apparatus 10 according to the first embodiment has been described as an example in which the annular member 16 is fitted into the groove 31 of the tool bit 26, and the friction stir welding apparatus 100 according to the third embodiment has been described as an example in which the annular member 104 is fitted into the groove 102 of the shoulder member 18. As another example, grooves may be formed in both the pin 26 and the shoulder member 18, and the annular members may be fitted into the respective grooves.

In this case, the annular member fitted in the groove of the pin 26 may be disposed on the side of the joint portion 23 with respect to the annular member fitted in the groove of the shoulder member 18. Alternatively, the annular member fitted in the groove of the shoulder member 18 may be disposed on the side of the joint portion 23 with respect to the annular member fitted in the groove of the head 26. By disposing the annular member fitted in the groove portion of the shoulder member 18 on the joining portion 23 side, the annular member fitted in the groove portion of the shoulder member 18 can be brought close to the end portion 26b side of the pin 26, and the penetration of chips can be suppressed on the end portion (tip end portion) 26b side of the pin 26.

In addition, the second embodiment may be combined with the fourth embodiment, as in the configuration in which the first embodiment is combined with the third embodiment.

In addition, the components in the above-described embodiment can be replaced with known components as appropriate without departing from the scope of the present invention, and the above-described modifications can be combined as appropriate.