JP2002316275A - Friction stirring and joining method, and heater of friction stirring and joining tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a friction stirring and joining method capable of preventing chipping of a joining head which can occur when the joining head is embedded in a joining starting part, and preventing defective joining caused by shortage of plastic flow which can occur at the joining starting part, and a heater of a friction stirring and joining tool. SOLUTION: This heater 20 comprises a casing 21 for accommodating the joining head 13 of the joining tool 10, and a heat source 22 for heating the joining head 13 accommodated in the casing 21. When starting the friction stirring and joining, the joining head 13 is heated in advance by this heater 20. The joining head 13 is embedded in the joining starting part of a member to be joined to perform the joining.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a friction stir welding method and a heating apparatus for a tool for friction stir welding, and more particularly to a friction stir welding method capable of favorably joining a joining member made of a metal material such as aluminum. The present invention relates to a welding method and a heating device for a friction stir welding tool used at this time.

[0002] In this specification, the term "aluminum" is used to include its alloy.

[0003]

2. Description of the Related Art Friction stir welding is in the category of solid-phase welding, and has advantages such as extremely little deformation such as thermal distortion due to welding, and there is no limitation on the type of metal material as a joining member. In recent years, it has been used as a joining means for various structures.

[0004] The joining method of the friction stir welding will be briefly described. First, the joining head of the joining tool is rotated, and the tip end of the rotating joining head is brought into contact with the joining start portion of the joining member of the joining member. Then, this is buried in the joining start portion. Then, the joining member is softened in the vicinity of the contact portion with the joining head due to the frictional heat generated by the rotation of the joining head, and the meat in the softened portion is stirred and mixed by receiving the rotational force of the joining head. Become.
Then, the probe is moved relative to the joining member along the portion to be joined while keeping the probe in the embedded state. Thereby, the meat of the joining member softened by the frictional heat is plastically flowed to fill the passage groove of the joining head by receiving the advancing pressure of the joining head while being stirred and mixed by the joining head,
Rapidly loses frictional heat and cools and solidifies. This phenomenon is sequentially repeated as the joining head moves. And when the joining head reaches the joining end part of the joining scheduled part,
Joining ends. By this joining operation, the joining members are joined at the joining head passing portion.

[0005]

However, the friction stir welding method has the following problems.

That is, in order to join the portions to be joined of the joining member, when the tip of the joining head is buried in the joining start portion, the tip of the joining head receives resistance at the time of implantation, and a part of the tip is subjected to resistance. There was a problem of loss.

[0007] Immediately after the joining head is embedded,
Since the joining member has not been sufficiently warmed, good plastic flow has hardly occurred. Therefore, there has been a problem that a joining defect due to insufficient plastic flow occurs inside the joining start portion. On the other hand, if the embedment depth of the joining head is increased to increase the amount of frictional heat to warm the joining start portion of the joining member, only this joining start portion becomes deeper than the desired joining depth, A problem arises in that a joint having a uniform joint depth cannot be formed.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and an object of the present invention is to prevent the joint head from being lost when the joint head is buried in a joint start portion. Another object of the present invention is to provide a friction stir welding method and a friction stir welding tool heating device which can prevent a joining defect due to insufficient plastic flow that may occur at a welding start portion.

[0009]

In order to achieve the above object, a friction stir welding method according to the present invention (claim 1) is to heat a welding head of a welding tool in advance at the start of friction stir welding. It is characterized by.

In this case, when starting the friction stir welding, the welding head of the welding tool is heated in advance so that when the welding head comes into contact with the welding start portion of the welding member,
The joint start portion softens quickly. As a result,
The resistance at the time of embedding the joining head is reduced, so that the defect of the joining head is prevented or suppressed. Furthermore, as described above, the joining start portion softens quickly, so that the meat in the softened portion can be favorably plastic-flowed. As a result, the occurrence of joining defects due to insufficient plastic flow can be prevented or It will be suppressed. In addition, it is not necessary to increase the burying depth of the joining head, so that a joining portion having a uniform joining depth can be formed.

[0011] In the friction stir welding method, it is preferable that the welding head is heated such that the temperature increases toward the tip of the welding head.

In this case, the defect of the joining head is reliably prevented or suppressed, and the occurrence of the joining defect due to insufficient plastic flow is reliably prevented or suppressed.

[0013] A friction stir welding tool heating apparatus according to the present invention includes a casing for accommodating a welding head of the welding tool, and a heat source for heating the welding head accommodated in the casing. (Claim 3).

In this heating device, the welding head of the welding tool is housed in a casing and heated by a heat source. That is, since the joining head is heated in the casing, it is difficult for heat generated from the heat source to escape, so that the joining head is efficiently heated.

In the heating device according to the third aspect of the present invention, the heat source is not particularly limited, and various heat sources can be adopted. For example, an electric heater or a hot air such as a gas flame may be used. Although an electric heater can be employed, it is desirable to employ an electric heater among these heat sources, since automation of heating and adjustment of the temperature in the casing can be easily performed. When the joining head of the joining tool is made of a conductive material such as metal, an induction current may be generated in the joining head by an induction heating device to heat the joining head itself. Alternatively, the joining head accommodated in the casing may be indirectly heated by mounting the induction heating coil on the casing and causing the induction heating coil to generate heat.

The welding head of the welding tool heated by the heating device is taken out of the casing at the start of the friction stir welding, and the tip of the welding head is moved as soon as possible to the welding start portion of the portion to be welded. And is embedded in the joining start portion. At the time of this embedding, since the joining head is heated in advance, when the tip end of the joining head comes into contact with the joining start portion, the joining start portion quickly softens. As a result, the resistance at the time of embedding the joining head is reduced, so that the loss of the joining head is prevented or suppressed. Furthermore, as described above, the joining start portion softens quickly, so that the meat in the softened portion can be favorably plastic-flowed. As a result, the occurrence of joining defects due to insufficient plastic flow can be prevented or It will be suppressed. In addition, it is not necessary to increase the burying depth of the joining head at the joining start portion, so that a joining portion having a uniform joining depth can be formed.

[0017] In the above-mentioned heating device, it is preferable that a temperature adjusting device for adjusting the temperature in the casing is provided.

In this case, the temperature in the casing can be set to a desired temperature without fail.

In the above heating device, it is preferable that the heat source heats the joining head housed in the casing such that the temperature of the joining head becomes higher as it reaches the tip of the joining head.

In this case, the joining head is efficiently heated.

[0021] In the above heating device, it is preferable that the casing is provided with an electric heater as the heat source, and is formed of a cylindrical body that accommodates the joining head by inserting it in the axial direction from an opening at an end thereof.

In this case, the operation of housing the joining head can be easily performed. Further, in a state where the joining head is housed in the casing, the joining head can be arranged in a manner along the axial direction of the casing, so that the outer peripheral surface of the joining head is heated substantially uniformly in the circumferential direction. Become like

[0023]

Next, an embodiment of the present invention will be described with reference to the drawings.

In FIG. 1, (10) is a welding tool for friction stir welding, and (1) is a plate-like welding member. In this embodiment, the joining member (1) is composed of two long aluminum plates (2) and (2) having the same thickness.
The end in the width direction of one plate (2) and the end in the width direction of the other plate (2) are arranged so as to abut each other. In this embodiment, the butting portion (3) of the two plates (2) and (2) is joined by friction stir welding.
2 shows a case in which the two plates (2) and (2) are integrated by joining along. Therefore, in this embodiment, the butted portion (3) of the two plates (2) and (2) is the portion to be joined. (3a) shows a joining start portion of the butting portion (3).

The joining tool (10) has a large-diameter cylindrical rotor (11) whose tip (11a) is pressed against the surface of the joining member (1), and a tip face (11b) of the rotor (11). And a small-diameter pin-shaped probe (12) which is integrally formed at the center of rotation of the joint member so as to protrude along the axis of rotation and is embedded in the butted portion (3) of the joining member (1). In this embodiment, the welding head (13) of the welding tool (10) includes the tip (11a) of the rotor (11) and the probe (12). Reference numeral (14) denotes a holder mounted on the base end of the rotor (11).

In this joining tool (10), the rotor (1
The probe (1) and the probe (12) are made of a metal heat-resistant material that is harder than the joining member (1) and can withstand frictional heat generated during joining. On the outer peripheral surface of the probe (12), a projection for stirring for stirring the meat of the joining member (1) softened by frictional heat is formed.

FIG. 2 shows a heating device (20) for heating the welding head (13) of the welding tool (10).

In the figure, (21) is a joining member (1).
The casing is disposed in close proximity to the casing. The casing (21) is made of a heat-resistant material having a predetermined shape retention property and capable of withstanding heat from the heat source (22). As shown in FIG. 3, the joining head of the joining tool (10) is used. The joining head (13) is a cap-shaped member that is put on the hat-like shape of (13), and surrounds the vicinity of the vicinity of the joining head (13).
Is to accommodate.

The construction of the casing (21) will be described. The casing (21) is formed of a cylindrical body having a bottom (21a) that protrudes in a dome shape. It is to be an outlet. The inside diameter of this casing (21) is equal to the rotor (1) of the welding tool (10).
It is set to the same size or slightly larger than the outer diameter of 1). The length from the end opening to the bottom (21) inside the casing (21) is substantially the same as the length obtained by adding the length of the rotor (11) and the length of the probe (12). With this configuration, when the probe (12) and the rotor (11) are housed, the end of the casing (21) is positioned near the base end of the rotor (11). ing. In the casing (21), the joining head (13) of the joining tool (10) is inserted in the axial direction of the casing (21) from an end opening of the casing (21) and is housed in the casing (21). You.

Inside the peripheral wall of the casing (21), a heating wire (23) of an electric heater serving as a heat source (22) for heating the housed joining head (13) is provided around an axis of the casing (21). The casing (21) is buried at a predetermined pitch over substantially the entire length of the casing (21). The pitch of the heating wires (23) near the bottom (21a) of the casing (21) is set smaller than the pitch of the heating wires (23) near the end of the casing (21). As a result, the temperature in the casing (21) increases as it proceeds from the end of the casing (21) to the bottom (21a). Further, since the casing (21) has the bottom (21a), the temperature in the casing (21) is set to be significantly higher as going from the end of the casing (21) to the bottom (21a). I have. Moreover,
Since the escape of heat in the casing (21) is prevented or suppressed by the bottom portion (21a), such a state can be quickly realized.

The heating wire (23) is, as shown in FIG.
The power supply cord (25) is connected to a power supply (24) for supplying power to the heating wire (23). Further, a temperature measuring device (for example, a thermocouple, 29) for measuring the temperature inside the casing (21) is mounted on the casing (21), and the temperature measuring device (29) is connected via a signal line (30). And is connected to an energization current control device (28) described later.

On the other hand, the power supply (24) has a built-in temperature control device (26) for controlling the temperature inside the casing (21). The temperature control device (26) includes an energization time control device (a so-called timer, 27) for controlling the energization time to the heating wire (23), and a heating wire (23) based on a signal from the temperature measuring device (29). ) For controlling the current supplied to the power supply.

In the temperature control device (26) of this embodiment,
The temperature in the casing (21) is adjusted by operating the power supply time control device (27) to control the power supply time to the heating wire (23), and / or the power supply current control device (28)
Is operated to control the current flowing through the heating wire (23), thereby adjusting the temperature inside the casing (21).

Next, a method of performing friction stir welding on the butting portion (3) of the joining member (1) using the heating device (20) having the above-described configuration will be described.

First, power is supplied from the power supply (24) to the heating wire (23).
To generate heat in the heating wire (23). Due to this heat generation, the temperature inside the casing (21) increases. At this time,
As described above, the pitch of the heating wires (23) near the bottom (21a) of the casing (21) is set to be smaller than the pitch of the heating wires (23) near the end of the casing (21). Therefore, the temperature in the casing (21) increases as it proceeds from the end of the casing (21) to the bottom (21a). Furthermore, in the casing (21) of this embodiment, the escape of heat in the casing (21) is prevented or suppressed by the bottom portion (21a), and thus such a state can be quickly realized.

Next, the welding head (1) of the welding tool (10)
3) is inserted in the axial direction of the casing (21) from the end opening of the casing (21), and is inserted into the casing (13).
(See FIG. 3). In this housed state, the inner diameter of the casing (21) is set to be equal to or slightly larger than the outer diameter of the rotor (11) as described above. ) Are arranged in the central portion inside the casing (21) in a manner along the axial direction. Therefore, the outer peripheral surfaces of the rotor (11) and the probe (12) can be substantially uniformly heated in the circumferential direction. In addition, the temperature in the casing (21) increases from the end of the casing (21) to the bottom (21a). Therefore, with this temperature distribution, the joining head (13) moves toward the tip. The temperature is increased so that the temperature of the probe (12) becomes higher than the temperature of the rotor (11). Further, since the inner diameter of the casing (21) is set to be equal to or slightly larger than the outer diameter of the rotor (11), the outer peripheral surface of the rotor (11) and the inner peripheral Almost no gap is formed between the surface and the surface, so that the escape of heat can be more reliably prevented or suppressed, and the joining head (13) can be efficiently heated. In addition, since the rotor (11) and the probe (12) can be heated from a position close thereto, the joining head (13) can be heated more efficiently. In addition,
In the present invention, after the joining head (13) is housed in the casing (21) in advance, the heating wire (23) may be heated to increase the temperature in the casing (21). is there.

When the joining member (1) is made of aluminum, the average temperature from the distal end of the probe (12) to the proximal end of the rotor (11) is adjusted to 150 ± 50 ° C. It is desirable to heat, especially the temperature of the probe (12) is 300 ± 50 ° C., the temperature of the middle part in the longitudinal direction of the rotor (11) is 150 ± 50 ° C., and the temperature of the base part of the rotor (11) Is desirably heated to 80 ± 50 ° C. The temperature inside the casing (21) is adjusted and set by the temperature adjusting device (26) so as to be in such a temperature state. Note that this temperature condition is such that the bonding member (1)
This is particularly effective when the joining member (1) is made of aluminum of 000 series and the thickness of the joining member (1) is 5 mm.

After the rotor (11) and the probe (12) of the joining tool (10) are raised to a desired temperature by the heating device (20), the rotor (11) and the probe ( 12) is pulled out of the casing (21), and the tip of the probe (12) is connected to the joining member (1) while rotating the rotor (11) and the probe (12) as shown in FIG. Joining part (3)
The probe (12) is pressed against a) to join the joint (3a)
Embed in it. At this time, since the probe (12) is pre-heated, the pressing causes the joining start portion (3a) to be quickly softened. Therefore, the resistance of the probe (12) at the time of implantation is reduced, and the loss of the probe (12) is prevented or suppressed. In the present invention, it goes without saying that the rotor (11) and the probe (12) may be rotated in advance in the casing (21) and then pulled out.

As described above, the probe (12) is embedded in the joining start portion (3a), and the tip surface (11b) of the rotor (11) is further pressed against the surface of the joining member (1). Then, in this state, the probe (12) is moved along the butting portion (3).

As the probe (12) moves, the butting portion (3) is sequentially joined by the probe (12) at the probe embedding position. That is, the frictional heat generated by the rotation of the probe (12) and the tip surface (11
The joining member (1) is softened in the vicinity of the probe embedding position by the frictional heat generated due to the sliding between b) and the surface of the joining member (1), and the flesh in the softened portion is reduced by the probe (12). The mixture is stirred and mixed by receiving the rotational force of.
Then, while this meat is stirred and mixed, the probe (12)
After receiving the advancing pressure, it plastically flows to fill the passage groove of the probe (12), and then rapidly loses frictional heat and solidifies by cooling. This phenomenon is sequentially repeated as the probe (12) moves. Then, when the probe (12) reaches the joining end portion, the joining ends, and the probe (12) is pulled out. By this joining operation, the butt portion (3) of the joining member (1) is joined at the probe passing portion (that is, over the region from the joining start portion (3a) to the joining end portion). (W) is a joint.

According to this friction stir welding method, when the probe (12) is pressed against the welding start portion (3a), the welding start portion (3a) is quickly softened, so that the meat in the softened portion is good. Therefore, the occurrence of joining defects due to insufficient plastic flow can be prevented or suppressed. Also, the probe (1
Since it is not necessary to increase the embedding depth of 2), a joint (W) having a uniform joint depth can be formed, and a high-quality joint can be obtained.

Although the embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various settings can be changed.

For example, in the above embodiment, the joining operation
This is achieved by moving the probe (12) embedded in the butt portion (3) of the joining member (1) along the butt portion (3). In the present invention, the probe (12) is used.
Instead of moving the probe, the position of the probe (12) embedded in the butting portion (3) of the joining member (1) is fixed, and the joining is performed so that the butting portion (3) sequentially passes through the probe. This may be performed by moving the member (1).

Further, the electric heater may be a planar heater.

[0045]

As described above, according to the friction stir welding method according to the present invention (claim 1), the welding head of the welding tool is heated before starting the friction stir welding. Therefore, the resistance at the time of embedding the joining head can be reduced, so that the loss of the joining head can be prevented or suppressed. Furthermore, at the time of embedding of the welding head, since the flesh of the welding member softened by the frictional heat flows well, the occurrence of welding defects due to insufficient plastic flow can be prevented or suppressed. . In addition, since it is not necessary to increase the burying depth of the joining head, a joining portion having a uniform joining depth can be formed.

In the friction stir welding method, when the welding head is heated so as to increase in temperature as it reaches the tip of the welding head (claim 2), it is necessary to reliably prevent or suppress the loss of the welding head. And the occurrence of joining defects due to insufficient plastic flow can be reliably prevented or suppressed.

According to the heating device for a friction stir welding tool according to the present invention (claim 3), a casing accommodating the welding head of the welding tool, a heat source for heating the welding head accommodated in the casing, , The joining head can be efficiently heated. For this reason, this heating device can be suitably used as a preheating device for pre-heating the welding head of the welding tool at the start of the friction stir welding.

In the above-mentioned heating device, when a temperature adjusting device for adjusting the temperature in the casing is provided (claim 4), the temperature in the casing can be set to a desired temperature without fail.

In the above heating device, when the heat source heats the joining head housed in the casing such that the temperature of the joining head increases toward the tip of the joining head (claim 5), the joining head is heated. Further, heating can be performed more efficiently.

In the above-mentioned heating device, when the casing is formed of a cylindrical body which accommodates the joining head inserted in the axial direction from the opening at the end thereof (claim 6), the joining head can be easily accommodated. it can.

[Brief description of the drawings]

FIG. 1 is a perspective view illustrating a friction stir welding method according to an embodiment of the present invention.

FIG. 2 is a perspective view showing a heating device for the friction stir welding tool according to the embodiment of the present invention.

FIG. 3 is a partially cutaway side view showing the heating device in a state in which a welding head of a welding tool is housed.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Joining member 3 ... Butt part (to-be-joined part) 3a ... Joining start part 10 ... Joining tool 11 ... Rotor 11a ... Rotor tip part 11b ... Rotor tip face 12 ... Probe 13 ... Joining head 20 ... Heating Apparatus 21 ... Casing 22 ... Heat source 23 ... Heating wire of electric heater 26 ... Temperature controller

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Kaoru Kawada 1-480 Inuzuka, Oyama City, Tochigi Prefecture Showa Denko KK Oyama Office F-term (reference) 4E067 BG00 CA03 DC05

Claims (6)

[Claims] 1. A friction stir welding method, wherein a welding head (13) of a welding tool (10) is heated in advance at the start of friction stir welding. 2. The friction stir welding method according to claim 1, wherein the welding head is heated such that the temperature increases toward the tip of the welding head. 3. A casing (21) containing a joining head (13) of a joining tool (10), and a heat source (22) for heating the joining head (13) contained in the casing. A heating device for a tool for friction stir welding, characterized in that: 4. A heating device for a friction stir welding tool according to claim 3, further comprising a temperature control device (26) for controlling a temperature in the casing. 5. The friction stir welding according to claim 3, wherein the heat source (22) heats the welding head housed in the casing so that the temperature of the welding head increases toward the tip of the welding head. Tool heating equipment. 6. The heat source (2) is provided in the casing (21).
The heating device for a friction stir welding tool according to any one of claims 3 to 5, further comprising an electric heater as (2), and a cylindrical body that accommodates the welding head inserted in an axial direction from an opening at an end thereof.