JP6213956B2 - Joining method and joining apparatus - Google Patents

Description

  The present invention relates to a bonding method and a bonding apparatus for a material to be bonded such as a metal plate.

  In recent years, considering the impact on the global environment, the need to use Al alloys and high-tensile steel plates as structural members in the automotive industry to reduce the weight of automobiles has been increasing in order to reduce exhaust emissions and improve fuel efficiency. . In the industrial field such as the automobile industry, resistance spot welding (RSW) has been used for many years to connect structural materials. In the aerospace field, structural materials such as Al alloys, Ti alloys, and FRP have been used. As a method of connecting the two, a joining method using a rivet or a resistance welding is used. However, an extremely high current is required to join a material with low electrical resistance such as an Al alloy by RSW, and a large-capacity welding power source and switchboard are required.

  As a method for connecting metal members such as an Al alloy, a friction stir welding method or a friction stir spot welding method that is performed without using a connecting material such as resistance welding or rivet is known (Patent Documents 1 to 5). The friction stir spot joining method generates frictional heat by rotating the probe (pin-shaped hard metal) at a high speed at the position of the metal member to be joined, and plastically flows the member to be joined by frictional heat. This is a method of joining the members by generating a stirring region between the members to be joined, and a joining method derived from the friction stir welding method. Patent Document 6 is a method in which a rivet is pressed into a material while rotating, and Patent Document 7 is a method in which a split pin is rotationally pressed into the material, and the rivet and the pin are left in the material and joined.

JP 2003-154472 A JP 2006-136906 A JP 2007-880 A JP 2012-196680 A JP-A-11-156561 Published in the US 2005 / 0178816A1 US release 2011 / 0073634A1

  The method of joining members such as metal plates using the friction stir welding method or the friction stir spot joining method has the advantage that energy saving can be achieved as compared with resistance welding, and the joining operation is easy. However, in the friction stir welding method or the friction stir spot joining method, since the probe hole remains at the position where the tool is pulled out from the member after joining or the part where the member is joined, the thickness of the member is partially reduced, The problem that the strength is lowered and the method of leaving the joining pin in the joined portion have a problem that the joining portion is not sufficiently strong because the joining pin is not integrated with the member.

  The present invention has been made to solve these problems, and provides a joining method and a joining apparatus that can reliably join a material to be joined such as a metal plate using a friction stir spot joining method. The purpose is to do.

A joining apparatus according to the present invention is a joining apparatus that joins a material to be joined using a tool including a probe that penetrates into a material to be joined, and that drives the probe to penetrate the material to be joined while rotating the tool. The apparatus includes a device and a mold that supports a material to be joined at the time of a joining operation and has a molding concave portion that molds the tip of the probe that penetrates the material to be joined to have a larger diameter than the probe , and rotates the tool. When the probe is penetrated into the material to be joined, the material to be joined is joined by a friction stir action .
When the tool is rotated by the drive device and penetrates into the material to be joined, the material to be joined is joined by the friction stir action, and the tip of the probe that penetrates the material to be joined is formed with a die larger in diameter than the probe. Thus, the materials to be joined are firmly joined.

Molding the tip of the probe to have a larger diameter than the probe means that when the tip of the probe is molded into a hemispherical shape following the molding recess of the mold, the molded part at the tip of the probe It is intended to be molded so as to be locked. Therefore, the shape of the molded part at the tip of the probe is not limited to a hemispherical shape, and can be configured to be locked as a polygonal body.
The tool including a probe is meant to include both a tool composed of a single probe and a tool composed of a probe and a tool body having a diameter larger than that of the probe. When a tool consisting of a probe and a tool body is used, the material to be joined is caulked and fixed by the tip of the probe molded by the mold and the tool body during the joining operation, making the material to be joined stronger. Be joined.
The materials to be joined can be joined without providing a pilot hole, or can be joined with a pilot hole provided in advance. When a prepared hole is provided in the material to be joined, the probe is positioned in a prepared hole provided in advance in the material to be joined, and the probe is penetrated and joined to the material to be joined while rotating the tool.

The joining method according to the present invention is a joining method for joining a material to be joined using a tool including a probe that penetrates the material to be joined, and the probe is inserted into the material to be joined while rotating the tool. Then, when joining the materials to be joined, the tip of the probe that penetrates the material to be joined is molded to have a diameter larger than that of the probe by using a mold having a molding recess into which the tip of the probe is pushed. When the probe is inserted into the material to be joined while rotating the tool, the material to be joined is joined by a friction stir action .
When the probe is inserted into the material to be bonded while rotating the tool, the material to be bonded can be firmly bonded by bonding the material to be bonded by friction stir action.
Further, by positioning the probe in a prepared hole provided in advance in the material to be joined and penetrating the probe into the material to be joined while rotating the tool, the joining position can be accurately positioned and joined.
Moreover, by using a tool comprising a probe and a tool body formed larger in diameter than the probe as the tool, the materials to be joined can be firmly joined.

  The joining method and joining apparatus according to the present invention can be suitably used for joining plate materials such as plate-shaped metal plates, but the material to be joined in the present invention is not limited to a plate material, and the material to be joined. The material, shape, thickness, and size are not limited. Further, the number of joined materials (number) is not limited, and the present invention can be applied to joining of two or more (multiple) joined materials.

  According to the material joining method and the joining apparatus according to the present invention, the materials to be joined can be reliably and firmly joined by an extremely easy operation.

It is explanatory drawing which shows 1st Embodiment about the joining method of a board | plate material. It is explanatory drawing which shows 2nd Embodiment about the joining method of a board | plate material. It is the external view (a) of a tool used for the joining test of a board | plate material, (b), and sectional drawing (c) of a metal mold | die. It is the external appearance photograph of the tool side and metal mold | die side of the board | plate material after joining when a pilot hole diameter is 3.2 mm. It is the external appearance photograph of the tool side of a joining part, and a metal mold | die side when joining using a cylindrical probe for a pilot hole diameter of 2.8mm, 3.0mm, 3.2mm, 3.4mm, 3.6mm. It is a cross-sectional photograph of the joint when the pilot hole diameter is 3.0 mm, 3.2 mm, and 3.4 mm. It is a cross-sectional photograph which shows the change of the front-end | tip shape of a probe when changing the amount of pushing of a tool. It is a graph which shows the tension test result at the time of joining when using a cylindrical probe and joining using the conventional rivet. It is the external appearance photograph of the tool side and metal mold | die side of a joining part when it joins using a screw-shaped probe with a pilot hole diameter of 2.5mm and 2.6mm. It is a cross-sectional photograph of a junction part. It is a graph which shows the tension test result at the time of joining using the tool provided with a screw-shaped probe and joining using the conventional rivet.

(First embodiment)
FIG. 1 shows a first embodiment of a method for joining plate members according to the present invention.
In the method for joining plate members shown in FIG. 1, plate members 12 and 13 which are materials to be joined are set on a mold 10, and a tool is attached to the plate members 12 and 13 while rotating a joining tool 14 by a driving device (not shown). This is a method of joining the plate members 12 and 13 by penetrating 14.

  The tool 14 includes a cylindrical tool body 14a that is chucked and held by a driving device, and a probe 14b that extends from the tool body 14a to a diameter smaller than that of the tool body 14a. The probe 14b is provided with a length that penetrates the plate members 12 and 13 in the thickness direction during the operation of joining the plate members 12 and 13.

  On the upper surface of the mold 10, a dish-shaped (inner surface is hemispherical) molding recess 10a is provided. When the plate members 12 and 13 are joined to each other, the molding concave portion 10a is inserted into the tip portion of the probe 14b penetrating the plate members 12 and 13 in the thickness direction, and the tip portion is formed into a hemispherical shape (rivet head shape). It is for plastic forming. The diameter of the molding recess 10a is set larger than the outer diameter of the probe 14b.

FIG. 1A shows a state in which the plate materials 12 and 13 are set on the mold 10 and the tool 14 is positioned above the molding recess 10 a of the mold 10. The position of the molding recess 10 a of the mold 10 is a planar position where the plate members 12 and 13 are joined.
The tool 14 is supported by a driving device such as a milling machine, the probe 14b of the tool 14 and the center of the molding recess 10a of the mold 10 are aligned, and the tool 14 is press-fitted into the plate members 12 and 13 while rotating at high speed.

  FIG. 1B shows a state where the probe 14b of the rule 14 is inserted through the plate members 12 and 13 while rotating the tool 14 at a high speed. The tip of the probe 14b penetrates the plate members 12 and 13 and enters the molding recess 10a. If the tool 14 is inserted into the plate members 12 and 13 while rotating at a high speed, the probe 14b enters the plate members 12 and 13 while plastically fluidizing the plate members 12 and 13 due to frictional stirring between the probe 14b and the plate members 12 and 13. The plate materials 12 and 13 are penetrated.

The probe 14b that has entered the molding recess 10a is further pressed down to be shaped into a hemisphere following the inner surface of the molding recess 10a of the mold 10.
In FIG. 1C, after the tip of the probe 14 b penetrating the plate materials 12 and 13 is formed into a hemispherical shape by the mold 10, the rotation of the tool 14 is stopped and the plate materials 12 and 13 are pulled upward from the mold 10. Indicates the state.
The plate members 12 and 13 are fastened by caulking in the thickness direction between a forming portion 14c in which the tip of the probe 14b of the tool 14 is formed in a hemispherical shape and a lower surface (shoulder portion) of the tool main body 14a. In the part where the probe 14b penetrates the plate members 12 and 13, the plate members 12 and 13 are joined and integrally connected by friction stir action, and the plate members 12 and 13 are fixed by caulking in the thickness direction by the probe 14b. Is firmly fixed.

  In this joining method, the plates 14 and 13 are joined by the tool 14 in a point-joint manner by friction stir action, and are caulked and fixed in the thickness direction. Therefore, the forming portion 14d of the probe 14b penetrating the plates 12 and 13 and the tool The length of the probe 14b is set according to the thickness of the plate members 12 and 13 so as to be caulked by the main body 14a, and the amount of pushing the probe 14b into the molding recess 10a of the mold 10 is adjusted.

  After the plate members 12 and 13 are fastened by the tool 14 (FIG. 1 (c)), the tool body 14a is removed as necessary. Since the plate members 12 and 13 are fixed by the friction stir action, the entire tool main body 14a on the plate member 13 may be removed, or the tool main body 14a is partially used to reduce the protruding height of the tool main body 14a. It may be deleted. If the height of the tool body 14a is set to a level that does not hinder the product after the joining operation, post-processing after the joining operation is unnecessary.

(Second Embodiment)
FIG. 2 shows a second embodiment of the method for joining plate members according to the present invention.
The method for joining plate members of the present embodiment is a method in which prepared holes 12 a and 13 a are provided in advance in the plate members 12 and 13 and are joined using the mold 10 and the tool 14. The use of the tool 14 including the tool main body 14a and the probe 14b and the use of the mold 10 including the molding recess 10a for molding the tip portion of the probe 14b are the same as in the first embodiment.

FIG. 2A shows a state in which the plate materials 12 and 13 are set on the mold 10. The plate members 12 and 13 are set by aligning the center of the pilot holes 12 a and 13 a with the center of the molding recess 10 a of the mold 10.
FIG. 2B shows a state in which the probe 14b of the tool 14 is inserted into the pilot holes 12a and 13a of the plate members 12 and 13 while the tip of the probe 14b is pushed into the molding recess 10a while rotating the tool 14 at a high speed. is there.
FIG. 2 (c) shows a state in which the connecting portion between the probe 14b and the tool body 14a is broken after the tip of the probe 14b is formed by the forming recess 10a. 14d is a fracture part.

  As in this embodiment, plate holes 12a and 13a are provided in plate members 12 and 13 which are materials to be joined, and a method of bonding plate members 12 and 13 using friction stirrer is as follows. Compared to the method of joining without providing 13a, the probe 14b can be easily penetrated into the plates 12 and 13 and can be easily joined by friction stirring, and the probe 14b is guided by the pilot holes 12a and 13a, so that the joining is accurately performed. There is an advantage that the position can be set. However, there are a problem that the pilot holes 12a and 13a must be processed in advance in the plate members 12 and 13, and a problem that the pilot holes 12a and 13a must be aligned at the time of joining.

  In addition, 1st Embodiment and 2nd Embodiment are the examples which join the board | plate materials 12 and 13 which are to-be-joined materials using the tool 14 which integrated the tool main body 14a and the probe 14b. . As a joining tool, a tool including only the probe 14a can be used. In this case, the base portion of the probe 14a is chucked and supported by a driving device, and the probe 14a is pushed into the plate members 12 and 13 while being rotationally driven, and the tip portion of the probe 14a penetrating the plate members 12 and 13 is formed into a hemispherical shape. do it. The base portion of the probe 14a is broken as necessary. Even when a tool including only the probe 14a is used, the plate members 12 and 13 can be reliably and firmly joined as in the case where the tool 14 of the above example is used.

An experiment was conducted in which the plate material was actually joined using a method of joining the plate material with a pilot hole (the method of the second embodiment). The experimental results will be described below.
3A and 3B are external views of the tool used in the experiment. As the tool, a tool having a cylindrical probe (FIG. 3A) and a tool having a probe threaded on the outer peripheral surface (FIG. 3B) were used.
The tool was an aluminum alloy (A7075). The probe diameter is 3 mm (screw: M3), the probe length is 7 mm, and the outer diameter of the probe body is 10 mm.
For the mold, die steel (SKD11) is used, the depth of the molding recess is 1 mm, and the diameter of the molding recess is 6 mm (FIG. 3C).
The plate material used for joining is made of an aluminum alloy (A7075) with a plate thickness of 2 mm. A general-purpose vertical milling machine with a rotation speed of 765 rpm was used as a tool driving device.

(Example using a tool with a cylindrical probe)
FIG. 4 is an appearance photograph showing a state in which the plate members after bonding the plate members are viewed from the tool side and a state viewed from the mold side. On the surface of the plate material on the tool side, a trace of the tool body contacting and rubbing against the upper surface of the plate material remains in a circular shape, and the upper end of the probe is broken. On the surface of the plate on the mold side, the tip of the probe is formed and protrudes from the surface of the plate.

FIG. 5 shows the appearance of the joined portion of the plate material after joining. These are photographs of the external appearance of the tool side and die side of the material to be joined when the pilot hole diameter is 2.8 mm, 3.0 mm, 3.2 mm, 3.4 mm, and 3.6 mm, respectively.
FIGS. 5A and 5B show a state in which the probe is not molded because the probe is broken in the plate material and the tip of the probe penetrating the plate material is not sufficiently adhered to the mold and is not sufficiently compressed. .
FIGS. 5C to 5F show examples in which the probe is broken near the shoulder of the tool after the tip of the probe is formed. The trace which the shoulder of the tool contacted on the tool side surface of a board | plate material is left.
FIGS. 5G and 5H are examples in which the probe is broken near the shoulder after the probe tip is molded. In this case, the amount of protrusion of the probe from the plate material was smaller than that in FIGS.
FIGS. 5 (i) and 5 (j) are examples in which, since the pilot hole is large with respect to the probe, the probe fell off from the plate material after joining and could not be joined.
The probe tip of the tool was neatly shaped into a hemisphere by the mold when the pilot hole diameter was 3.0 mm or 3.2 mm.

FIG. 6 is a cross-sectional photograph of a joint having pilot hole diameters of 3.0 mm, 3.2 mm, and 3.4 mm. As the pilot hole diameter increases, the thickness of the probe increases, and the deformation of the probe tip increases.
FIG. 7 shows how the probe shape changes depending on the amount of pressing of the tool when the pilot hole diameter is 3.2 mm. That is, the insertion amount (pushing amount) of the tool is increased, the thickness of the probe is increased, the tip of the probe is gradually enlarged in accordance with the shape of the molding concave portion of the mold, and the lower surface of the plate material is locked. It can be seen that it will be molded. In addition, the probe is thought to be broken due to the increase in probe thickness and contact with the pilot hole.

FIG. 8 shows the results of a tensile test for the case where the plate materials used in the joining test were joined (fastened) using rivets and the case where the plates were joined using the tool described above.
As a comparative test for joining using rivets, a sample joined using a round rivet and a sample joined using a blind rivet were prepared.
A round rivet with a nominal diameter of 3 mm, length of 6 mm, and material A1070 was used. A 3 mm pilot hole was drilled in the plate, and the rivet head was molded with a hammer and joined to form a sample.
As a blind rivet, a blind rivet with a diameter of 3.2 mm, a length of 6 mm, and a flange material A5052 was used. The blind rivet was inserted into a clearance hole with a diameter of 3.4 mm and joined by pulling a mandrel.

FIG. 8 shows the load applied to the joint and the sample at that time for the sample joined using the above tools with pilot hole diameters of 3.0 mm, 3.2 mm, and 3.4 mm, and the sample joined using the round rivet and blind rivet. The result of measuring the amount of displacement is shown.
The test results in FIG. 8 show that the joining method using the tool according to the present invention is far superior in joining strength and load durability compared with the conventional joining method using a round rivet and a blind rivet, and is a plate material joining method. It shows that it is effective.

(Example using a tool with a threaded probe)
FIG. 9 shows a state in which the joined portions are viewed from the tool side and the mold side when the plate materials (the pilot hole diameters of 2.5 mm and 2.6 mm) are joined using a tool having a screw-type probe. It can be seen that the tip of the probe is hemispherical and that the probe is broken near the shoulder.

  FIG. 10 is a cross-sectional photograph of the joint (prepared hole diameter 2.5 mm). It can be seen that the probe tip penetrating the plate material along the pilot hole is formed in a hemispherical shape. The pilot hole provided in the plate has a smaller diameter than the probe of the tool, but when inserted, the screw thread with a small deformation resistance is cut to the plate, and the probe diameter and pilot hole are the same size.

FIG. 11 shows the load applied to the joint and the sample for the sample joined using the above tools with the pilot hole diameters of 2.5 mm and 2.6 mm and the sample joined using the conventional rivet (round rivet, blind rivet). The result of measuring the amount of displacement is shown. The same round rivet and blind rivet as described above were used.
FIG. 11 shows that the joining strength of the method of joining plate members using the tool of the method of the present invention is clearly improved as compared with the method of joining plate members using conventional rivets.

DESCRIPTION OF SYMBOLS 10 Mold 10a Molding recessed part 12, 13 Plate material 12a, 13a Pilot hole 14 Tool 14a Tool main body 14b Probe 14c Molding part 14d Breaking part

Claims (6)

A joining apparatus for joining a material to be joined using a tool including a probe that penetrates the material to be joined,
A driving device for penetrating the probe into the workpiece while rotating the tool;
A mold provided with a molding concave portion for supporting the material to be joined at the time of the joining operation and molding the tip of the probe penetrating the material to be joined to have a larger diameter than the probe ,
A joining apparatus for joining a material to be joined by a friction stir action when a probe is inserted into the material to be joined while rotating the tool . 2. The joining apparatus according to claim 1 , wherein a tool comprising a probe and a tool main body having a larger diameter than the probe is used. A joining method for joining materials to be joined using a tool having a probe that penetrates the materials to be joined,
When the probe is inserted into the material to be joined while rotating the tool and the material to be joined is joined, the tip of the probe that has penetrated the material to be joined is provided with a molding concave portion into which the tip of the probe is pushed. Using a mold, mold to a larger diameter than the probe,
A joining method comprising joining a material to be joined by friction stir action when a probe is inserted into the material to be joined while rotating the tool . 4. The joining method according to claim 3, wherein the probe is inserted into the material to be joined while the tool is rotated by aligning the probe in a prepared hole provided in advance in the material to be joined. The joining method according to claim 3 or 4 , wherein a tool comprising a probe and a tool body formed larger in diameter than the probe is used as the tool. The joining method according to claim 5 , wherein after joining materials to be joined by the tool, all or part of the tool body is removed.