JP6766377B2 - Joining method - Google Patents

Description

The present invention relates to a joining method for joining metal members by friction stir welding.

For example, Patent Document 1 describes a joining method in which a first metal member and a second metal member are superposed to form a polymerized portion, and then a rotating tool is inserted from the surface of the second metal member to friction stir weld the polymerized portions. Is described. In the friction stir welding, friction stir welding is performed with only the stirring pin in contact with the second metal member.

JP-A-2015-139800

In the conventional joining method, since the plastically fluidized metal is not pressed by the shoulder portion of the rotating tool, the plastically fluidized metal overflows to the outside, the joint portion becomes short of metal, and the surface of the second metal member is recessed. There is a problem that grooves are formed.

Therefore, an object of the present invention is to provide a joining method capable of preventing a metal shortage at the joining portion.

The present invention to solve the previous SL problems is a joining method for joining a first metal member and a second metal member by using a rotary tool with a stirring pin, wherein a surface of said first metal member A polymerization step of superimposing the back surfaces of the second metal member to form a polymerized portion, an arrangement step of arranging the auxiliary member so as to make surface contact with the surface of the second metal member, and the rotating stirring pin of the auxiliary member. The rotating tool is inserted in a state where only the stirring pin is in contact with the second metal member and the auxiliary member, or the first metal member, the second metal member and the auxiliary member. It includes a friction stirring step of joining the first metal member, the second metal member and the auxiliary member by relative movement, and a removal step of removing the auxiliary member on which burrs are formed from the second metal member. When a line passing through the end face of the auxiliary member and orthogonal to the first metal member and the second metal member is used as a reference line, the rotation center axis of the rotation tool and the reference line overlap in the friction stirring step. The stirring pin is relatively moved as described above, and the joining conditions are set so that burrs are formed on the auxiliary member.

According to such a joining method, it is possible to prevent a metal shortage in the joined portion by joining the polymerized portion and simultaneously friction stir welding the auxiliary member in addition to the first metal member and the second metal member. This makes it possible to prevent the formation of concave grooves on the surface of the second metal member. Further, since the auxiliary member remains on only one side of the rotating tool, the removal step can be easily performed.

Further, in order to solve the above-mentioned problems, the present invention is a joining method for joining a first metal member and a second metal member by using a rotation tool provided with a stirring pin, and is applied to the surface of the first metal member. A polymerization step of superimposing the back surfaces of the second metal member to form a polymerized portion, an arrangement step of arranging an auxiliary member so as to make surface contact with the surface of the second metal member, and the rotating stirrer pin are assisted. The rotating tool is inserted from the surface side of the member, and only the stirring pin is in contact with the second metal member and the auxiliary member, or the first metal member, the second metal member, and the auxiliary member. A friction stirring step of joining the first metal member, the second metal member, and the auxiliary member by relative movement, and a removal step of removing the auxiliary member on which burrs are formed from the second metal member. In the case where a line that includes, passes through the end face of the auxiliary member and is orthogonal to the first metal member and the second metal member is used as a reference line, in the friction stirring step, after the friction stirring step is performed, one side of the rotating tool is used. The rotation center axis of the rotation tool is slightly shifted to the center side of the auxiliary member to move relative to the extent that the auxiliary member remains, and burrs are formed on the remaining auxiliary member. It is characterized in that the joining conditions are set as described above .

According to such a joining method, it is possible to prevent a metal shortage in the joined portion by joining the polymerized portion and simultaneously friction stir welding the auxiliary member in addition to the first metal member and the second metal member. This makes it possible to prevent the formation of concave grooves on the surface of the second metal member. Further, since the auxiliary member remains only on the side with respect to the rotation tool, the removal step can be easily performed. Further, since the rotation center axis of the rotation tool is shifted to the center side of the auxiliary member from the reference line, it is possible to more reliably prevent the metal shortage of the joint portion. In addition, the rotation tool can be easily inserted into the auxiliary member.

According to the joining method according to the present invention, it is possible to prevent a metal shortage at the joint.

It is sectional drawing which shows the polymerization process and arrangement process of 1st Embodiment of this invention. It is sectional drawing which shows the friction stir welding process which concerns on 1st Embodiment. It is sectional drawing which shows after the friction stir welding step which concerns on 1st Embodiment. It is sectional drawing which shows the removal process which concerns on 1st Embodiment. It is sectional drawing which shows after the removal process which concerns on 1st Embodiment. It is sectional drawing which shows the polymerization process and arrangement process which concerns on 2nd Embodiment. It is sectional drawing which shows the friction stir welding process which concerns on 2nd Embodiment. It is sectional drawing which shows the removal process which concerns on 2nd Embodiment. It is sectional drawing which shows the polymerization process and arrangement process which concerns on 3rd Embodiment. It is sectional drawing which shows the friction stir welding process which concerns on 3rd Embodiment. It is sectional drawing which shows the removal process which concerns on 3rd Embodiment.

[First Embodiment]
The joining method according to the first embodiment of the present invention will be described in detail with reference to the drawings. In the joining method according to the present embodiment, a polymerization step, a placement step, a friction stir step, and a removal step are performed. In the following description, the "front surface" means the surface opposite to the "back surface".

The polymerization step is a step of superimposing the first metal member 1 and the second metal member 2 as shown in FIG. The first metal member 1 and the second metal member 2 are metal plate-shaped members. The materials of the first metal member 1 and the second metal member 2 are not particularly limited as long as they are metals that can be agitated by friction. For example, aluminum, aluminum alloy, copper, copper alloy, titanium, titanium alloy, magnesium, magnesium alloy and the like. It may be selected appropriately from. The plate thicknesses of the first metal member 1 and the second metal member 2 are the same. The plate thicknesses of the first metal member 1 and the second metal member 2 may be appropriately set. In the polymerization step, the front surface 1b of the first metal member 1 and the back surface 2c of the second metal member 2 are overlapped to form the polymerization portion J1.

The arranging step is a step of arranging the auxiliary member 10 on the second metal member 2. The auxiliary member 10 is a metal plate-shaped member. The auxiliary member 10 is not particularly limited as long as it is a metal capable of friction stir welding, but in the present embodiment, it is made of the same material as the first metal member 1 and the second metal member 2. The plate thickness of the auxiliary member 10 is appropriately set so that the plasticized region W after the friction stir welding step described later does not run out of metal. In the present embodiment, the plate thickness of the auxiliary member 10 is set to be thinner than that of the first metal member 1 and the second metal member 2.

In the arranging step, the back surface 10c of the auxiliary member 10 and the front surface 2b of the second metal member 2 are brought into surface contact with each other. Further, the first metal member 1, the second metal member 2, and the auxiliary member 10 are immovably restrained on the gantry T by using a jig (not shown). Although the auxiliary member 10 has a plate shape in the present embodiment, it may have another shape.

As shown in FIG. 2, the friction stir welding step is a step of joining the superposed portion J1 of the first metal member 1 and the second metal member 2 by friction stir welding using the joining rotary tool F. The joining rotary tool F is composed of a connecting portion F1 and a stirring pin F2. The rotary tool F for joining corresponds to the "rotation tool" in the claims. The rotary tool F for joining is made of, for example, tool steel. The connecting portion F1 is a portion connected to a rotating shaft (not shown) of the friction stirrer. The connecting portion F1 has a columnar shape.

The stirring pin F2 hangs down from the connecting portion F1 and is coaxial with the connecting portion F1. The stirring pin F2 is tapered as it is separated from the connecting portion F1. A spiral groove is engraved on the outer peripheral surface of the stirring pin F2. In the present embodiment, in order to rotate the joining rotation tool F counterclockwise, the spiral groove is formed clockwise from the base end to the tip end. In other words, the spiral groove is formed clockwise when viewed from above when the spiral groove is traced from the base end to the tip end.

When the joint rotation tool F is rotated clockwise, it is preferable to form the spiral groove counterclockwise from the base end to the tip end. In other words, the spiral groove in this case is formed counterclockwise when viewed from above when the spiral groove is traced from the base end to the tip end. By setting the spiral groove in this way, the metal plastically fluidized during friction stir welding is guided to the tip end side of the stirring pin F2 by the spiral groove. As a result, the amount of metal that overflows to the outside of the metal member to be joined (first metal member 1, second metal member 2 and auxiliary member 10) can be reduced. The spiral groove may be omitted.

The joining rotary tool F may be attached to a friction stir device such as a machining center, or may be attached to, for example, an arm robot having a rotating means such as a spindle unit at the tip. By attaching the joining rotation tool F to the arm robot, the rotation center axis Fc of the joining rotation tool F can be easily tilted.

In the friction stir welding step, only the stirring pin F2 rotated counterclockwise is inserted into the polymerization portion J1 and the metal member to be joined and the connecting portion F1 are relatively moved while being separated from each other. In other words, friction stir welding is performed with the base end portion of the stirring pin F2 exposed. Here, as shown in FIG. 1, a line that passes through the end surface 10a of the auxiliary member 10 and is orthogonal to the first metal member 1 and the second metal member 2 is defined as a reference line Z. In the friction stir welding step, the rotation center axis Fc of the joining rotation tool F is placed on the reference line Z, and the first metal member 1, the second metal member 2, and the auxiliary member 10 are brought into contact with the stirring pin F2. The joint rotation tool F is relatively moved in this state.

In the present embodiment, the traveling direction of the joining rotation tool F is set so that the auxiliary member 10 is located on the left side of the traveling direction of the joining rotation tool F. The rotation direction and the traveling direction of the joining rotation tool F are not limited to those described above, and may be appropriately set. For example, the joining rotation tool F may be rotated clockwise while the auxiliary member 10 is arranged on the left side in the traveling direction of the joining rotation tool F. Alternatively, the joining rotation tool F may be rotated to the left or right while the auxiliary member 10 is arranged on the right side in the traveling direction of the joining rotation tool F. Conditions such as the rotation direction of the joining rotation tool F and the preferable positional relationship of the auxiliary member 10 will be described later.

In the present embodiment, the insertion depth of the stirring pin F2 is set so that the stirring pin F2 reaches the first metal member 1. The polymerized portion J1 may be frictionally agitated with the stirring pin F2 in contact with only the second metal member 2 and the auxiliary member 10. In this case, the polymerized portion J1 is plastically fluidized and joined by the frictional heat between the stirring pin F2, the second metal member 2, and the auxiliary member 10. A plasticized region W is formed in the movement locus of the joining rotation tool F. After the friction stir welding step, as shown in FIG. 3, a burr V is formed at the end of the auxiliary member 10.

The removing step is a step of removing the auxiliary member 10 from the second metal member 2, as shown in FIGS. 4 and 5. In the removing step, for example, the auxiliary member 10 is manually bent in a direction away from the second metal member 2 and removed from the second metal member 2. As a result, as shown in FIG. 5, the first metal member 1 and the second metal member 2 are joined in the plate thickness direction.

According to the joining method according to the present embodiment described above, the first metal member 1 and the second metal member 2 are joined, and in addition to the first metal member 1 and the second metal member 2, the auxiliary member 10 is also formed. By friction stir welding at the same time, it is possible to prevent metal shortage in the joint portion (plasticized region W). This makes it possible to prevent the formation of a concave groove on the surface 2b of the second metal member 2.

Further, according to the present embodiment, the burr V is formed on the auxiliary member 10 by the friction stir welding step, but the auxiliary member 10 can be removed together with the auxiliary member 10 in the removing step. Thereby, the work of removing the burr can be easily performed. As shown in FIG. 3, after the friction stir welding step, the end face of the auxiliary member 10 is inclined so as to become thinner toward the center of the plasticized region W. A removing device or the like may be used for the auxiliary member 10, but in the present embodiment, the auxiliary member 10 can be easily removed manually.

Here, in the joining method according to the present embodiment, since the auxiliary member 10 is set thinner than the first metal member 1 and the second metal member 2, the shoulder portion of the rotation tool is pushed into the metal member as in the conventional case. However, when frictional stirring is performed, the auxiliary member 10 is blown to the outside due to the contact between the shoulder portion and the auxiliary member 10, and the metal shortage at the joint portion cannot be compensated. However, in the present embodiment, since friction stirring is performed while only the stirring pin F2 of the joining rotary tool F is in contact with the first metal member 1, the second metal member 2, and the auxiliary member 10, the auxiliary member 10 is blown to the outside. It is possible to make up for the metal shortage at the joint without being damaged. In addition, the load acting on the friction stirr can be reduced as compared with the case where the shoulder portion of the rotary tool is brought into contact with each other.

Further, as shown in FIG. 2, in the friction stir step according to the present embodiment, the auxiliary member 10 is arranged on the left side in the traveling direction and the joining rotation tool F is rotated counterclockwise, so that the auxiliary member 10 side is the Re side. The Re side is the side where the magnitude of the feed rate is subtracted from the magnitude of the tangential velocity on the outer circumference of the joining rotation tool F. On the other hand, the opposite side of the Re side is the Ad side. The Ad side is the side to which the magnitude of the feed rate is added from the magnitude of the tangential velocity on the outer circumference of the joining rotation tool F.

For example, when the rotation speed of the joining rotation tool F is slow, the temperature of the plastic fluid material is more likely to rise on the Ad side than on the Re side of the plasticization region W, so that many burrs V are generated on the Ad side. Tend to do. On the other hand, for example, when the rotation speed of the joining rotation tool F is high, the temperature of the plastic fluid material rises on the Ad side, but burrs V tend to occur on the Re side due to the high rotation speed.

In the present embodiment, since the rotation speed of the joining rotation tool F is set to be high, burr V is generated on the Re side, that is, on the auxiliary member 10 side. That is, in the present embodiment, the rotation speed, rotation direction, traveling direction, etc. of the joining rotation tool F are set so that a large number of burrs V are formed on the auxiliary member 10 side. As a result, the burr V formed on the auxiliary member 10 is removed together with the auxiliary member 10, so that the burr removing step can be performed more easily. Further, by setting the rotation speed of the joining rotation tool F to be high, the moving speed (feeding speed) of the joining rotation tool F can be increased. As a result, the joining cycle can be shortened.

As described above, which side of the joining rotary tool F in which the burr V is generated during the friction stir step differs depending on the joining conditions. The joining conditions include the rotation speed, rotation direction, movement speed (feed speed) of the joining rotation tool F, the inclination angle (taper angle) of the stirring pin F2, the first metal member 1, the second metal member 2, and the auxiliary member. It is determined by each element such as 10 materials and the thickness of each member and the combination of these elements. It is preferable that the auxiliary member 10 is arranged on the side where the burr V is generated or the side where the burr V is generated abundantly according to the joining conditions because the burr removing step can be easily performed.

[Second Embodiment]
Next, the joining method according to the second embodiment will be described. The joining method according to the second embodiment is different from the first embodiment in that the rotating tool F for joining is inserted from the central portion of the auxiliary member 10. In the joining method according to the second embodiment, the parts different from the first embodiment will be mainly described.

The joining method according to the present embodiment includes a polymerization step, an arrangement step, a friction stir step, and a removal step. Since the polymerization step is the same as that of the first embodiment, the description thereof will be omitted. The arranging step is a step of arranging the auxiliary member 10 on the surface 2b of the second metal member 2.

In the arranging step, as shown in FIG. 6, the back surface 10c of the auxiliary member 10 is brought into surface contact with the front surface 2b of the second metal member 2. The plate thickness of the auxiliary member 10 is appropriately set so that the plasticized region W after the friction stir welding step described later does not run out of metal. Further, the first metal member 1, the second metal member 2, and the auxiliary member 10 are immovably restrained by using a jig (not shown).

As shown in FIG. 7, the friction stir welding step is a step of joining the superposed portion J1 of the first metal member 1 and the second metal member 2 by friction stir welding using the joining rotary tool F. In the friction stir step, the stirring pin F2 rotated clockwise is inserted from the central portion of the surface 10b of the auxiliary member 10, and the insertion depth of the stirring pin F2 is set so as to reach the first metal member 1. In the friction stir welding step, only the stirring pin F2 rotated clockwise is inserted into the polymerization portion J1 and the metal member to be welded and the connecting portion F1 are moved while being separated from each other. In other words, friction stir welding is performed with the base end portion of the stirring pin F2 exposed. In the present embodiment, in order to rotate the joining rotation tool F clockwise, the spiral groove of the stirring pin F2 is formed counterclockwise from the base end to the tip end.

Then, the joining rotary tool F is relatively moved along the polymerization portion J1 in a state where the first metal member 1, the second metal member 2, and the auxiliary member 10 are in contact with the stirring pin F2. As a result, the polymerization section J1 is friction stir welded. A plasticized region W is formed in the movement locus of the joining rotation tool F. In this embodiment, since the joining rotation tool F is rotated at high speed, burrs tend to occur more on the Re side than on the Ad side. As in the first embodiment, the stirring pin F2 may be brought into contact with only the second metal member 2 and the auxiliary member 10 (so as not to reach the first metal member 1) to perform frictional stirring.

As shown in FIG. 8, the removing step is a step of removing the auxiliary member 10 separated by the friction stir welding step from the first metal member 1 and the second metal member 2. In the removing step, the auxiliary members 10 and 10 are bent and removed in the directions away from the second metal member 2.

According to the joining method according to the present embodiment described above, the first metal member 1 and the second metal member 2 are joined, and in addition to the first metal member 1 and the second metal member 2, the auxiliary member 10 is also formed. By friction stir welding at the same time, it is possible to prevent metal shortage in the joint portion (plasticized region W). Further, by inserting the stirring pin F2 from the central portion of the auxiliary member 10, it is possible to more reliably prevent the metal shortage at the joint portion and to replenish the metal in a well-balanced manner. Further, since the central portion of the auxiliary member 10 is flat, the stirring pin F2 can be easily inserted into the auxiliary member 10.

Further, according to the present embodiment, burrs V and V are formed on the auxiliary members 10 and 10 separated by the friction stir welding step, respectively, but the auxiliary members 10 can be removed together in the removing step. Thereby, the work of removing the burr can be easily performed. As shown in FIG. 8, after the friction stir welding step, the end face of the auxiliary member 10 is inclined so that the plate thickness becomes thinner toward the central portion. A removing device or the like may be used for the auxiliary member 10, but in the present embodiment, the auxiliary member 10 can be easily removed by hand.

[Third Embodiment]
Next, the joining method according to the third embodiment of the present invention will be described. As shown in FIGS. 9 and 10, in the joining method according to the third embodiment, the insertion position of the stirring pin F2 is mainly different from that of the first embodiment. The joining method according to the third embodiment will mainly explain the differences from the first embodiment. The joining method according to the third embodiment includes a polymerization step, an arrangement step, a friction stir welding step, and a removal step.

Since the polymerization step is the same as that of the first embodiment, the description thereof will be omitted. As shown in FIG. 9, the arranging step is a step of bringing the front surface 2b of the second metal member 2 and the back surface 10c of the auxiliary member 10 into surface contact. In the present embodiment, the auxiliary member 10 is arranged so that the auxiliary member 10 is located on the right side in the traveling direction of the joining rotation tool F.

As shown in FIG. 10, the friction stir welding step is a step of joining the superposed portion J1 of the first metal member 1 and the second metal member 2 by friction stir welding using the joining rotary tool F. In the present embodiment, in order to rotate the joining rotation tool F clockwise, the spiral groove of the stirring pin F2 is formed counterclockwise from the base end to the tip end.

In the friction stir welding step, only the stirring pin F2, in which the rotation center axis Fc of the joining rotation tool F is rotated clockwise to the overlapping portion J1 while being positioned slightly closer to the center side of the auxiliary member 10 than the reference line Z. Is inserted, and the metal member to be joined and the connecting portion F1 are relatively moved while being separated from each other. In the present embodiment, the traveling direction of the joining rotation tool F is set so that the auxiliary member 10 is located on the right side of the traveling direction of the joining rotation tool F, and the joint rotation tool F is rotated at high speed. As a result, in the present embodiment, the auxiliary member 10 side becomes the Re side, and many burrs V are generated in the auxiliary member 10. The insertion position of the joining rotation tool F in the present embodiment (distance between the rotation center axis Fc of the joining rotation tool F and the reference line Z) is assisted only on one side of the joining rotation tool F after performing the friction stir step. Adjust appropriately so that the member 10 remains.

As shown in FIG. 11, the removing step is a step of removing the auxiliary member 10 from the second metal member 2. In the removing step, for example, the auxiliary member 10 is manually bent in a direction away from the second metal member 2 and removed from the second metal member 2.

According to the joining method according to the present embodiment described above, the first metal member 1 and the second metal member 2 are joined, and in addition to the first metal member 1 and the second metal member 2, the auxiliary member 10 is also formed. By friction stir welding at the same time, it is possible to prevent metal shortage in the joint portion (plasticized region W).

Further, according to the joining conditions of the present embodiment, since the rotation speed of the joining rotation tool F is set to be high, a large amount of burr V tends to occur on the Re side. That is, in the present embodiment, the rotation direction, the traveling direction, and the like (joining conditions) of the joining rotation tool F are set so that a large number of burrs V are formed on the auxiliary member 10. As a result, the burr V formed on the auxiliary member 10 is removed together with the auxiliary member 10, so that the burr removing step can be performed more easily. Further, as shown in FIG. 11, after the friction stir welding step, the end face of the auxiliary member 10 is inclined so as to become thinner toward the center of the plasticized region W. A removing device or the like may be used for the auxiliary member 10, but in the present embodiment, the auxiliary member 10 can be easily removed manually.

Here, in the removal step of the second embodiment described above, it is necessary to remove the auxiliary members 10 and 10 on both sides of the center of the plasticized region W. However, in the present embodiment, since the arrangement position of the auxiliary member 10 is adjusted so that the auxiliary member 10 does not remain on one side (left side in the traveling direction of the joining rotation tool F) after the friction stir welding step, the other side is adjusted in the removal step. It is only necessary to remove the auxiliary member 10 remaining in the. As a result, the labor of the removal process can be reduced. Further, since the rotation center axis Fc is slightly shifted to the center side of the auxiliary member 10 from the reference line Z, the metal shortage at the joint can be prevented in a well-balanced manner and more reliably. Further, since the rotation center axis Fc is slightly shifted to the center side of the auxiliary member 10 with respect to the reference line Z, the stirring pin F2 can be easily inserted into the auxiliary member 10.

Although the embodiments of the present invention have been described above, the design can be appropriately changed within a range not contrary to the gist of the present invention. For example, although the removal step was performed in the present embodiment, the auxiliary member 10 may be left as it is in the second metal member 2 without being removed.

1 1st metal member 2 2nd metal member 10 Auxiliary member F Rotation tool for joining (rotation tool)
F1 Connection part F2 Stirring pin Fc Rotation center axis J1 Polymerization part V Bali W Plasticization area Z Reference line

Claims (2)

A joining method for joining a first metal member and a second metal member using a rotating tool equipped with a stirring pin.
A polymerization step of superimposing the back surface of the second metal member on the surface of the first metal member to form a polymerization portion, and
An arrangement step of arranging the auxiliary member so as to make surface contact with the surface of the second metal member, and
The rotating stirring pin is inserted from the surface side of the auxiliary member, and only the stirring pin is attached to the second metal member and the auxiliary member, or the first metal member, the second metal member and the auxiliary member. A friction stir step of joining the first metal member, the second metal member, and the auxiliary member by relatively moving the rotating tool in contact with each other.
Including a removal step of removing the burr-formed auxiliary member from the second metal member.
When a line passing through the end face of the auxiliary member and orthogonal to the first metal member and the second metal member is used as a reference line.
The friction stir step is characterized in that the stirring pin is relatively moved so that the rotation center axis of the rotation tool and the reference line overlap, and the joining conditions are set so that burrs are formed on the auxiliary member. Joining method. A joining method for joining a first metal member and a second metal member using a rotating tool equipped with a stirring pin.
A polymerization step of superimposing the back surface of the second metal member on the surface of the first metal member to form a polymerization portion, and
An arrangement step of arranging the auxiliary member so as to make surface contact with the surface of the second metal member, and
The rotating stirring pin is inserted from the surface side of the auxiliary member, and only the stirring pin is attached to the second metal member and the auxiliary member, or the first metal member, the second metal member and the auxiliary member. A friction stir step of joining the first metal member, the second metal member, and the auxiliary member by relatively moving the rotating tool in contact with each other.
Including a removal step of removing the burr-formed auxiliary member from the second metal member.
When a line passing through the end face of the auxiliary member and orthogonal to the first metal member and the second metal member is used as a reference line.
In the friction stir welding step, the rotation center axis of the rotation tool is slightly biased toward the center side of the auxiliary member with respect to the reference line to the extent that the auxiliary member remains only on one side of the rotary tool after the friction stir welding step. A joining method characterized in that the joining conditions are set so that burrs are formed on the remaining auxiliary member while being moved and moved relative to each other.

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