JP6740960B2 - Joining method - Google Patents

Description

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

Friction stir welding (FSW) is known as a method of joining metal members to each other. Friction stir welding is a method in which the rotating tool is rotated and moved along the abutting portion between the metal members, and the frictional heat between the rotating tool and the metal member causes the metal in the abutting portion to plastically flow to solidify the metallic members. It is to join the phases.

For example, Patent Document 1 discloses a technique in which only a stirring pin of a rotary tool is inserted into an inner corner of vertically joined metal members to perform friction stir welding of a butted portion. By performing friction stir welding with the auxiliary member arranged in the inner corner, it is possible to prevent metal shortage at the joint.

JP, 2005-139799, A

However, the conventional friction stir welding method has a problem in that the burr removal step becomes complicated because a large amount of burr remains in the inner corner.

From such a viewpoint, the present invention provides a joining method capable of preventing metal shortage at the inner corners and easily removing burrs when friction stir welding the inner corners of the metal members. Is an issue.

In order to solve such a problem, the present invention prepares a plate-shaped first metal member in which a step portion is formed on the back surface of the end portion, and a preparation step of preparing a plate-shaped second metal member, The step bottom surface of the step portion of the first metal member and the end surface of the second metal member are butted to each other to form a first butting portion, and the step side surface of the step portion and the first metal member A butting step of butting a side surface to form a second butting portion, and an auxiliary member disposing step of disposing an auxiliary member at an inner corner formed by the back surface of the first metal member and the first side surface of the second metal member. An inner corner friction stir step of inserting a stirring pin of a rotary tool from the inner corner, relatively moving the rotary tool along the inner corner, and friction stir welding the second butting portion; Inserting the stirring pin of the rotating tool from the surface side of the metal member, the rotating tool is relatively moved along the step portion, the first butting portion friction stir step of friction stir welding the first butting portion, A removing step of removing the burr-formed auxiliary member from the first metal member or the second metal member, in the inner corner friction stirring step, only the stirring pin is the first metal member, and Friction stir welding the second butt portion in a state of contacting the second metal member and the auxiliary member, in the first butt portion friction stir step, only the stirring pin only the first metal member, or, It is characterized in that the first butting portion is friction stir welded in a state of being in contact with the first metal member and the second metal member.

According to such a joining method, since the auxiliary member is arranged in the inner corner and the friction stir welding of the inner corner is performed via the auxiliary member, it is possible to prevent metal shortage in the inner corner. Further, by providing the step portion on the first metal member, the positioning of the first metal member and the second metal member can be easily performed in the butting step. Moreover, the burr generated at the inner corner can be easily removed together with the auxiliary member. Further, in the inner corner friction stir process, since only the stirring pin is inserted into the inner corner, the load on the friction stirrer can be reduced.

Further, the present invention prepares a plate-shaped first metal member having a step portion formed on the back surface of the end portion, and a preparation step of preparing a plate-shaped second metal member, and the first metal member described above. The step bottom surface of the step portion and the end surface of the second metal member are butted to form a first butting portion, and the step side surface of the step portion and the first side surface of the second metallic member are butted to each other. A butting step of forming a butting portion; an auxiliary member disposing step of disposing an auxiliary member at an inner corner formed by the back surface of the first metal member and the first side surface of the second metal member; Inserting a stirring pin of one rotating tool, relatively moving the first rotating tool along the inner corner, an inner corner friction stir step of friction stir welding the second butt portion, and the first metal member Insert the stirring pin of the second rotating tool provided with a shoulder portion and a stirring pin from the surface side, relatively move along the step portion in a state where the shoulder portion is in contact with the surface of the first metal member, A first butting portion friction stir step of friction stir welding the first butting portion; and a removing step of removing the burr-formed auxiliary member from the first metal member or the second metal member, In the inner corner friction stir step, the second butting portion is friction stir welded in a state where only the stirring pin of the first rotating tool is in contact with the first metal member, the second metal member and the auxiliary member, and In the first butting portion friction stir step, the first butting portion is formed with the stirring pin of the second rotating tool in contact with only the first metal member or the first metal member and the second metal member. Characterized by friction stir welding.

According to such a joining method, since the auxiliary member is arranged in the inner corner and the friction stir welding of the inner corner is performed via the auxiliary member, it is possible to prevent metal shortage in the inner corner. Further, by providing the step portion on the first metal member, the positioning of the first metal member and the second metal member can be easily performed in the butting step. Moreover, the burr generated at the inner corner can be easily removed together with the auxiliary member. Further, in the inner corner friction stir process, only the stirring pin is inserted into the inner corner, so that the load on the friction stirrer can be reduced. Further, in the first butting portion friction stir step, since the plastic flow material can be suppressed in the shoulder portion, the occurrence of burrs can be reduced.

Further, in the inner corner friction stir step, it is preferable to set the welding conditions such that burrs generated in the friction stir welding are formed on the auxiliary member.

According to this joining method, the burr can be removed more easily.

According to the joining method of the present invention, when the inner corners of the metal members are friction stir welded, it is possible to prevent metal shortage in the inner corners and easily remove burrs.

It is sectional drawing which shows the preparation process and a matching process which concern on 1st embodiment. It is a perspective view which shows the 1st butt part friction stirring process which concerns on 1st embodiment. It is sectional drawing which shows the 1st butt part friction stirring process which concerns on 1st embodiment. It is a perspective view which shows the auxiliary member arrangement process which concerns on 1st embodiment. It is a perspective view showing an inner corner friction stir process concerning a first embodiment. It is sectional drawing which shows the inner corner friction stirring process which concerns on 1st embodiment. It is a perspective view showing an inner corner friction stir process concerning a second embodiment. It is sectional drawing which shows the 1st butt part friction stirring process which concerns on 2nd embodiment. It is sectional drawing which shows the 1st butt part friction stirring process which concerns on the modification of 2nd embodiment.

[First embodiment]
A joining method according to the first embodiment of the present invention will be described in detail with reference to the drawings. As shown in FIG. 1, in the joining method according to the first embodiment, the first metal member 1 and the second metal member 2 are abutted in an L shape and joined. The joining method according to the first embodiment includes a preparation step, a butting step, a tab material arranging step, a first butting portion friction stir step, an auxiliary member disposing step, an inner corner friction stir step, and a removing step. To do. In the description, the “front surface” means the surface opposite to the “back surface”.

The preparation step is a step of preparing 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 plate-shaped metal members. The materials of the first metal member 1 and the second metal member 2 are appropriately selected from friction stirrable metals such as aluminum, aluminum alloys, copper, copper alloys, titanium, titanium alloys, magnesium and magnesium alloys. A step portion 11 is formed on the back surface 1c at the end of the first metal member 1. The step portion 11 is composed of a step bottom surface 11a and a step side surface 11b rising vertically from the step bottom surface 11a. The width dimension of the step bottom surface 11 a is the same as the plate thickness dimension of the second metal member 2.

The abutting step is a step of abutting the first metal member 1 and the second metal member 2 in an L shape, as shown in FIG. In the butting step, the end face 2a of the second metal member 2 is butted against the step bottom surface 11a of the first metal member 1 to form the first butting portion J1, and the step side surface 11b is provided with the first side surface 2b of the second metal member 2. The second butting portion J2 is formed by butting. The end surface 1a of the first metal member 1 and the second side surface 2c of the second metal member 2 are flush with each other.

As shown in FIG. 2, the tab material arranging step is a step of arranging the tab materials T, T at both ends of the inner corner (only one is drawn in FIG. 2). The tab material T is a plate-shaped metal member made of the same material as the first metal member 1. The plate thickness dimension of the tab material T is the same as the plate thickness dimension of the first metal member 1. In the tab material arranging step, the side surface of the tab material T is abutted against the side surface 1d of the first metal member 1 and the abutting portion is welded. The front surface Ta of the tab material T and the front surface 1b of the first metal member 1 are flush with each other, and the back surface Tb of the tab material T and the back surface 1c of the first metal member 1 are flush with each other.

As shown in FIG. 2, the first butting portion friction stir step is a step of inserting the rotary tool F from the surface 1b of the first metal member 1 and friction stir welding the first butting portion J1. The rotary tool F includes a connecting portion F1 and a stirring pin F2, and is made of, for example, tool steel. The connecting portion F1 is a portion attached to a friction stirrer (not shown) and has a cylindrical 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 this embodiment, since the rotary tool F is rotated clockwise, the spiral groove is formed counterclockwise from the base end toward the tip.

When the rotary tool F is rotated counterclockwise, it is preferable to form the spiral groove clockwise from the base end toward the tip. By setting the spiral groove in this way, the metal that has been plastically fluidized during frictional stirring is guided to the tip side of the stirring pin F2 by the spiral groove. Thereby, the amount of metal overflowing to the outside of the metal members to be joined (the first metal member 1, the second metal member 2, and the auxiliary member 10) can be reduced.

In the first butting portion friction stir process, as shown in FIG. 2, the rotating tool F rotated clockwise is inserted into the start position Sp set on the surface Ta of the tab material T, and the step portion 11 (second metal member 2 ), the rotary tool F is relatively moved. As shown in FIG. 3, the insertion depth of the rotary tool F is set so that the stirring pin F2 contacts the first metal member 1 and the second metal member 2 in this embodiment. A plasticized region W1 is formed on the movement trajectory of the rotary tool F. The insertion depth of the stirring pin F2 may be set so as to contact only the first metal member 1. In this case, frictional heat between the stirring pin F2 and the first metal member 1 plastically fluidizes and joins around the first butting portion J1.

The rotary tool F is preferably attached to a robot arm having a drive unit such as a spindle unit at its tip. This makes it possible to easily incline the central axis of rotation of the rotary tool F when performing the internal corner friction stir step described below.

The auxiliary member arranging step is a step of arranging the auxiliary member 10 at the inner corner as shown in FIG. The auxiliary member 10 is a plate-shaped metal member, and is formed of the same material as the first metal member 1 and the second metal member 2 in the present embodiment. In the auxiliary member disposing step, the back surface 10c of the auxiliary member 10 is brought into surface contact with the first side surface 2b of the second metal member 2, and the end surface 10d is brought into contact with the back surface 1c of the first metal member 1. The plate thickness dimension of the auxiliary member 10 is appropriately set so that a metal shortage does not occur at the joint after the inner corner friction stir step described later.

As shown in FIG. 5, the inner corner friction stir step is a step of inserting the stirring pin F2 from the inner corner and friction stir welding the second butting portion J2. In the inner corner friction stir process, the rotating tool F rotated clockwise is inserted at the start position Sp set on the surface Ta of the tab material T, and is moved along the second abutting portion J2 from the front side to the back side in FIG. And the rotary tool F is moved relatively. In this embodiment, the rotation speed of the rotary tool F is set to be low. The insertion depth and the insertion angle of the rotary tool F may be set appropriately. A plasticized region W2 is formed on the movement trajectory of the rotary tool F.

In the inner corner friction stir process, it is preferable to set the joining conditions so that the burr V is generated on the auxiliary member 10 side. The position where the burr V occurs differs depending on the bonding conditions. The welding conditions include the rotation speed of the rotary tool F, the rotation direction, the moving speed (feed speed), the traveling direction, the inclination angle (taper angle) of the stirring pin F2, the metal member to be welded (first metal member 1, second metal member). It is determined by each element such as the material of the metal member 2 and the auxiliary member 10), the thickness of the metal member to be joined, and the combination of these elements.

For example, when the rotation speed of the rotary tool F is slow, the shear side (advancing side) is compared to the flow side (retreating side (Re side): the side where the moving speed of the rotary tool is subtracted from the tangential speed at the outer circumference of the rotary tool F). side (Ad side): Since the temperature of the plastic flow material rises more easily on the side where the moving speed of the rotary tool F is added to the tangential speed on the outer circumference of the rotary tool F, the shear side is outside the plasticizing region. Many burrs tend to occur. On the other hand, for example, when the rotation speed of the rotary tool F is high, the temperature of the plastic flow material rises on the shear side, but due to the higher rotation speed, more burrs V tend to occur on the flow side outside the plasticizing region. It is in.

In the present embodiment, the rotation speed of the rotary tool F is set to be slow and the auxiliary member 10 is set to the left side in the traveling direction. Therefore, as shown in FIG. 6, the shear side outside the plasticizing region W2. A large amount of burr V tends to occur on the auxiliary member 10 which is The joining condition of the rotary tool F and the arrangement position of the auxiliary member 10 are not limited to those described here and may be set appropriately.

In this way, if the joining conditions are set so that the side where the burr V is generated or the side where the burr V is frequently generated is the side of the auxiliary member 10, as shown in FIG. 6, the burr V is formed on the surface 10b of the auxiliary member 10. Can be aggregated. Therefore, the removal step described later can be easily performed, which is preferable.

The removal step is a step of removing the auxiliary member 10 from the second metal member 2, as shown in FIG. 6. Although not specifically shown, in the present embodiment, the tip of the auxiliary member 10 is bent and removed from the second metal member 2. Further, the tab materials T, T are removed from the first metal member 1.

According to the joining method according to the present embodiment described above, since the auxiliary member 10 is arranged at the inner corner and friction stir welding of the inner corner is performed via the auxiliary member 10, the plasticized region W2 formed at the inner corner. The metal shortage can be prevented. Thereby, the watertightness and airtightness of the inner corner can be enhanced.

Further, by providing the step portion 11 on the first metal member 1, the positioning of the first metal member 1 and the second metal member 2 can be easily performed in the butting process. In addition, since the distance from the surface 1b of the first metal member 1 to the first butting portion J1 can be shortened by providing the step portion 11, the stirring pin F2 can be easily inserted to the first butting portion J1. You can Further, according to this embodiment, the burr V generated at the inner corner can be easily removed together with the auxiliary member 10. Further, in the inner corner friction stir process, since only the stirring pin F2 is inserted into the inner corner, the load on the friction stirrer can be reduced.

Further, in the present embodiment, even in the first butting portion stirring step, only the stirring pin F2 is inserted to perform friction stirring, so that the load on the friction stirring device can be reduced.

[Second embodiment]
Next, a joining method according to the second embodiment of the present invention will be described. In the joining method according to the present embodiment, a preparation step, a butting step, a tab material arranging step, an auxiliary member arranging step, an inner corner friction stir step, a removing step, and a first butt section friction stir step, To do. The second embodiment differs from the first embodiment in that the first corner friction stir process is performed after the inner corner friction stir process is performed. The second embodiment will be described focusing on the parts different from the first embodiment.

The preparation process, the butting process, and the tab material arranging process are common to the first embodiment. In the auxiliary member disposing step, as shown in FIG. 7, the back surface 10c of the auxiliary member 10 is brought into surface contact with the back surface 1c of the first metal member 1.

In the inner corner friction stir process, as shown in FIG. 7, the rotation tool F rotated right at a low speed is inserted into the start position Sp set on the back surface Tb of the tab material T, and the rotation tool F is turned from the front side to the back side in FIG. Then, the rotary tool F is relatively moved along the second abutting portion J2. As a result, the second butting portion J2 is friction stir welded. A burr V (not shown) is formed on the surface 10b of the auxiliary member 10 by the inner corner friction stirring process.

In the removing step, as shown in FIG. 7, the auxiliary member 10 is removed from the first metal member 1. In the removing step, the end portion of the auxiliary member 10 is bent and cut off from the first metal member 1.

In the first butt section friction stir step, as shown in FIG. 8, the rotary tool F is inserted from the surface 1b of the first metal member 1 and the first butt section J1 is friction stir welded in the same manner as in the first embodiment. To do.

The second embodiment described above can also achieve the same effects as the first embodiment. Here, FIG. 9 is a cross-sectional view showing a first butting portion friction stirring process according to a modification of the second embodiment. In both the first embodiment and the second embodiment, as shown in FIG. 9, a second rotating tool G may be used in place of the rotating tool (first rotating tool) F in the first butting portion friction stirring process. .. The second rotary tool G has a shoulder portion G1 and a stirring pin G2 hanging from a lower end surface G1a of the shoulder portion G1. In the first butting portion friction stir step of the modified example, the lower end surface G1a of the shoulder portion G1 is brought into contact with the surface 1b of the first metal member 1 or is pushed about several millimeters while being friction stir welding along the first butting portion J1. I do. According to this modification, since the plastic fluid material can be suppressed in the shoulder portion G1, it is possible to reduce the occurrence of burrs. In the first butting portion friction stir step, the first butting portion J1 in a state where the stirring pin G2 of the second rotary tool G is in contact with only the first metal member 1 or the first metal member 1 and the second metal member 2. Friction stir welding.

Although the embodiments of the present invention have been described above, design changes can be made as appropriate within the scope of the present invention. For example, the temporary joining may be performed on the first butting portion J1 before performing the first butting portion friction stirring process. Moreover, you may perform temporary joining with respect to the 2nd butt part J2, before performing an inner corner friction stir process. The temporary joining may be performed by friction stirring or welding. Temporary joining may be performed at a spot or continuously.

Further, the auxiliary member may have an L-shaped cross section and may be arranged so as to cover the inner corner. In the removing step, the auxiliary member is removed from the first metal member 1 and the second metal member 2.

1 1st metal member 1b Front surface 1c Back surface 2 2nd metal member 2b 1st side surface 2c 2nd side surface J1 1st abutting part J2 2nd abutting part F Rotating tool (1st rotating tool)
F1 Connecting part F2 Stirring pin G Second rotating tool G1 Shoulder part G2 Stirring pin W1 Plasticizing region W2 Plasticizing region

Claims (3)

While preparing a plate-shaped first metal member having a step portion formed on the back surface of the end portion, a preparation step of preparing a plate-shaped second metal member,
The step bottom surface of the step portion of the first metal member and the end surface of the second metal member are butted to each other to form a first butting portion, and the step side surface of the step portion and the first metal member A butting step of butting the side surface to form a second butting portion,
An auxiliary member disposing step of disposing an auxiliary member at an inner corner formed by the back surface of the first metal member and the first side surface of the second metal member,
Inserting the stirring pin of the rotary tool from the inner corner, the rotary tool is relatively moved along the inner corner, the inner corner friction stir step of friction stir welding the second butt portion,
A first butting portion friction stirrer for inserting the stirring pin of the rotary tool from the front surface side of the first metal member and relatively moving the rotating tool along the step portion to frictionally stir the first butting portion. Process,
A removing step of removing the auxiliary member on which the burr is formed from the first metal member or the second metal member,
In the inner corner friction stir step, the second butting portion is friction stir welded in a state where only the stirring pin is in contact with the first metal member, the second metal member and the auxiliary member,
In the first butting part friction stir step, the first butting part is friction stir welded in a state where only the stirring pin is in contact with the first metal member only or the first metal member and the second metal member. A joining method characterized by: While preparing a plate-shaped first metal member having a step portion formed on the back surface of the end portion, a preparation step of preparing a plate-shaped second metal member,
The step bottom surface of the step portion of the first metal member and the end surface of the second metal member are butted to each other to form a first butting portion, and the step side surface of the step portion and the first metal member A butting step of butting the side surface to form a second butting portion,
An auxiliary member disposing step of disposing an auxiliary member at an inner corner formed by the back surface of the first metal member and the first side surface of the second metal member,
Inserting a stirring pin of the first rotating tool from the inner corner, relatively moving the first rotating tool along the inner corner, an inner corner friction stir step of friction stir welding the second butt portion,
Insert the stirring pin of the second rotary tool including the shoulder portion and the stirring pin from the surface side of the first metal member, and along the step portion in a state where the shoulder portion is in contact with the surface of the first metal member. And relatively moving the first butt portion friction stir welding of the first butt portion,
A removing step of removing the auxiliary member on which the burr is formed from the first metal member or the second metal member,
In the inner corner friction stir step, the second butting portion is friction stir welded in a state where only the stirring pin of the first rotating tool is in contact with the first metal member, the second metal member and the auxiliary member,
In the first butting portion friction stir step, the first butting portion in a state where the stirring pin of the second rotary tool is in contact with only the first metal member or the first metal member and the second metal member. A friction-stir welding method is used. The joining method according to claim 1 or 2, wherein in the inner corner friction stir step, the joining conditions are set so that burrs generated in the friction stir welding are formed on the auxiliary member.

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