JP7329161B1 - FRICTION STIR WELDING APPARATUS AND WELDING TOOL HOLDING METHOD - Google Patents

Abstract

A friction stir welding apparatus in which a welding tool is fixed to a welding tool holder by a fixture, and a method for holding the welding tool, in which the fixture is less likely to stick. A welding tool comprising a welding tool holding portion, a shoulder, and a probe is rotated at a target rotation speed and inserted into a member to be welded to a target depth, and the insertion portion of the member to be welded and its vicinity are softened. A friction stir welding apparatus for friction stir welding the members to be welded by advancing a welding tool, wherein the welding tool holding portion is inserted into an insertion portion of a welding tool holder to a predetermined position of the welding tool holding portion. In the fixing part formed by at least one mortar-shaped depression, the contact part of the fixture locked to the joining tool holder is locally formed on the circumference of the bottom part of the fixing part or on the slope part of the fixing part. It is characterized in that the welding tool is held in the welding tool holder by being brought into physical contact with each other. [Selection drawing] Fig. 7

Description

The present invention relates to a configuration of a welding tool of a friction stir welding apparatus for joining members to be welded together by friction stir welding, and a method of attaching the welding tool.

Friction Stir Welding (FSW), in which the materials to be welded are joined together by softening the materials to be welded by the frictional heat generated by rotating a cylindrical welding tool and stirring the softened part, is Since it does not use any raw materials, it has high fatigue strength, and since the material does not melt, it is possible to join with less welding deformation (distortion).

As a background art of this technical field, there is a technique such as Patent Document 1, for example. Patent Literature 1 describes "a holder having a hole opening on one end face, a shoulder part provided inside the hole of the holder, and an agitating pin part provided in the shoulder part, The shoulder part has a hole with a spiral groove on its inner wall, and the agitation pin part has a groove on its side that fits into the spiral groove on the inner wall of the hole in the shoulder part. and one end of which is connected to the agitation pin projecting from the end face of the shoulder part opposite to the holder side and the other end of the agitation pin, and has a cross section larger than the cross section of the agitation pin and a head provided at the holder-side end of the shoulder part. (Claim 1 of Patent Document 1)

JP 2022-32635 A

In Patent Document 1, the welding tool is held in the welding tool holder by tightening the flat surface with a bolt having a flat tip. (Fig. 1 and paragraph [0022] of Patent Document 1, etc.)
In terms of simply holding the welding tool in the welding tool holder, there is no problem with the holding method described in Patent Document 1.

However, with this holding method, if the welding tool is rotated and inserted into the workpiece and welding is continuously repeated, galling or sticking occurs between the threaded portion of the bolt and the threaded portion of the tool holder. , confirmed that it becomes difficult to remove the bolt.

As a result, problems such as poor workability occur when exchanging the welding tool.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a friction stir welding apparatus in which a welding tool is fixed to a welding tool holder by a fixture, and a method for holding the welding tool in which the fixture is less likely to stick.

In order to solve the above-mentioned problems, the present invention inserts a welding tool comprising a welding tool holder, a shoulder, and a probe into a member to be welded to a target depth while rotating at a target rotational speed. A friction stir welding apparatus for friction stir welding the members to be welded by advancing the welding tool while softening and the vicinity thereof, wherein the welding tool holder portion is inserted into the insertion portion of the welding tool holder, and the welding tool holder is inserted into the welding tool holder. In the fixing part formed by at least one mortar-shaped depression provided at a predetermined position of the tool holding part, the joining tool holder is engaged with the circumference of the bottom part of the fixing part or the slope part of the fixing part. The welding tool is held in the welding tool holder by locally contacting the contact portion of the fixing tool.

The present invention also provides a welding tool holding method for fixing a welding tool to a welding tool holder with a fixture, wherein the welding tool holding portion is inserted into the insertion portion of the welding tool holder, and a predetermined holding portion of the welding tool holding portion is held. In the fixing part formed by at least one mortar-shaped depression provided at the position of the fixing part, the contact part of the fixing tool is locally brought into contact with the circumference of the bottom part of the fixing part or the slope part of the fixing part It is characterized in that the welding tool is held in the welding tool holder by a fixture that engages the welding tool holder.

According to the present invention, in a friction stir welding apparatus in which a welding tool is fixed to a welding tool holder by a fixture, it is possible to realize a friction stir welding apparatus and a welding tool holding method in which the fixture is less likely to stick.

As a result, it is possible to improve the work efficiency when extracting the welding tool, such as replacing the welding tool.

Problems, configurations, and effects other than those described above will be clarified by the following description of the embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the whole friction stir welding apparatus outline|summary based on Example 1 of this invention. FIG. 10 is a diagram showing a state in which the welding tool is inserted into the welding tool holder and fixed; (When there is one fixing point) FIG. 10 is a diagram showing a state in which the welding tool is inserted into the welding tool holder and fixed; (When there are 2 fixing points) It is a figure which shows the structure of a joining tool holding part. (top view) It is a figure which shows the structure of a joining tool holding part. (Side view) It is a figure which shows a mortar-shaped fixing|fixed part. It is a figure which shows a mortar-shaped fixing|fixed part. It is a figure which shows the structure of a fixture. It is a figure which shows the front-end|tip part shape of a fixture. It is a figure which shows the front-end|tip part shape of a fixture. It is a figure which shows the front-end|tip part shape of a fixture. It is a figure which shows the state which the fixing tool and fixing|fixed part contact. It is a figure which shows the state which the fixture and fixing|fixed part which concern on Example 2 of this invention contacted.

Embodiments of the present invention will be described below with reference to the drawings. In addition, in each drawing, the same configurations are denoted by the same reference numerals, and detailed descriptions of overlapping portions are omitted.

Embodiment 1 A friction stir welding apparatus and a welding tool holding method according to Embodiment 1 of the present invention will be described with reference to FIGS.

FIG. 1 is a diagram showing an overall outline of a friction stir welding apparatus 1 of this embodiment.

As shown in FIG. 1, the friction stir welding apparatus 1 of the present embodiment includes, as main components, an apparatus main body 2 and a spindle support section 4 connected to the apparatus main body 2 via a Z-axis vertical movement drive mechanism section 3. , a spindle holder 15 held by the spindle support 4 , a welding tool holder 5 held by the spindle holder 15 , and a welding tool 6 held by the welding tool holder 5 .

As shown in FIG. 1, the Z-axis vertical motion drive mechanism 3 uses, for example, a ball screw, a linear guide, or the like. Drive in the axial direction (vertical direction).

The joining tool 6 is composed of a shoulder portion 7 and a probe portion (joining pin) 8 and is connected to a main shaft motor 14 via a main shaft 16 . A spindle motor 14 rotates the welding tool 6 in a predetermined direction.

The apparatus body 2 supports the spindle support section 4 via the Z-axis vertical motion drive mechanism section 3, and a control section (control device) 11 mounted (attached) to the apparatus body 2 gives a drive signal to the spindle motor 14. Then, the welding tool 6 is rotated and advanced along the welding line. That is, the apparatus main body 2 holds the spindle support portion 4, the spindle holder 15, and the welding tool holder 5, rotates the welding tool 6, and moves the welding tool 6 in the X-axis direction and the Z-axis direction in FIG. Let

While rotating the welding tool 6 at a predetermined number of rotations, the shoulder portion 7 and the probe portion 8 are pressed onto the bonding line of the surfaces of the members to be welded 9 (9a, 9b) placed on the mounting table 10 to generate frictional heat. is generated to soften the member to be welded 9, the shoulder portion 7 and the probe portion 8 are inserted into the member to be welded 9 by the required amount, and the number of rotations is maintained to generate plastic flow and stir the insertion portion. . By pulling out or moving the welding tool 6, the stirring portion (joining portion) is cooled, and the members 9 to be joined are joined.

The main shaft holder 15 is composed of a main shaft motor 14, a main shaft 16 directly connected to the main shaft motor 14, and a welding tool 6 directly connected to the main shaft 16. The joint line of the member 9 (the first member to be joined 9a and the second member to be joined 9b joined together) indicated by the line)), and at that position, the input heat treatment is performed until the welding temperature indicating the temperature of the member to be welded 9 near the welding tool 6 rises to a desired value, and then The welding tool 6 is advanced along the welding line to the end of the friction stir welding at a target advancing speed indicating a predetermined advancing speed, and the member to be welded 9 is friction stir welded.

1 shows a configuration in which the welding tool holder 5 and the welding tool 6 are connected (held) to the apparatus main body 2 via the spindle holder 15, the spindle support section 4, and the Z-axis vertical movement driving mechanism section 3. However, it is not limited to this. A configuration in which the welding tool holder 5 and the welding tool 6 are directly connected (held) to the device main body 2, or a configuration in which the welding tool holder 5 and the welding tool 6 are directly connected (held) to the device main body 2, or the structure shown in FIG. A configuration in which a C-shaped frame is provided, a configuration in which the apparatus is connected (held) to the device main body 2 having a multi-axis robot arm, etc. are also included in the scope of this embodiment.

In addition, the shoulder portion 7 and the probe portion (joining pin) 8 may be the same welding tool (that is, only the shoulder without the probe), or even if the shoulder portion 7 has a structure that does not rotate. good.

A controller (control device) 11 for controlling the operation of the friction stir welding apparatus 1 is installed (attached) to the apparatus main body 2 . A control unit (control device) 11 outputs a welding condition signal for determining the welding condition of the welding tool 6 and a vertical (Z direction) holding position of the welding tool 6 by the Z-axis vertical movement drive mechanism 3 (insertion position of the welding pin 8). A storage unit (not shown) for storing bonding parameters (FSW bonding conditions) such as a holding position determination signal for determining the amount) is provided. Note that the control unit 11 may be configured separately from the device body 2 as a control device.

Further, the device main body 2 is provided with an X-axis front-rear drive mechanism 12 that can be driven in the X-axis direction, and an X-axis front-rear drive motor 13 drives the upper part of the device main body 2 along the X-axis direction as a linear guide. , the welding tool holder 5 and the welding tool 6 can be moved in the X-axis direction (the welding direction).

A method of fixing the welding tool 6 (the shoulder portion 7 and the probe portion 8) to the welding tool holder 5 will be described with reference to FIGS. 2A and 2B. FIG. 2A is a diagram showing a state in which the welding tool 6 is inserted into the welding tool holder 5 and fixed, and shows a case where there is one fixed portion. FIG. 2B is a diagram showing a state in which the welding tool 6 is inserted into the welding tool holder 5 and fixed, and shows a case where there are two fixed portions.

The welding tool 6 (the shoulder portion 7 and the probe portion 8) is detachably held in the welding tool holder 5 by a fixture (set screw) 22. As shown in FIG. For example, when initially holding the welding tool 6 in the welding tool holder 5, the welding tool hole portion 19 of the welding tool 6 is inserted into the insertion portion 18 of the welding tool holder 5, and the welding tool holding portion 19 is held at a predetermined position. A fixing member 22 holds the fixing part 20 arranged in the . When the probe portion 8 of the welding tool 6 is worn or damaged, or when the type of the welding tool 6 is changed in order to friction stir weld another member 9 to be welded, the fixture 22 is removed and the welding tool 6 is removed. The joining tool holder 5 is pulled out from the insertion portion 18 , a new joining tool 6 is inserted into the joining tool holder 5 , and the fixed portion 20 is held by the fixture 22 .

In the present invention, unlike the prior art (Patent Document 1), the fixture 22 is attached to the fixing section 20 instead of making the tip portion of the fixture flat and abutting on the fixing section having a flat surface so as to be held in surface contact. The welding tool 6 is held in the welding tool holder 5 by local contact (point contact or line contact). A detailed description will be given below.

As shown in FIGS. 2A and 2B, the welding tool 6 (the shoulder portion 7 and the probe portion 8) has the welding tool holding portion 19 joined to the insertion portion 18 of the welding tool holder 5, and the cylindrical bottom surface of the welding tool holding portion 19 is joined. The tool holder 5 is inserted until it contacts the bottom surface of the tube, and at least one or more fixing parts 20 arranged at predetermined positions of the joining tool holding part 19 are held by the fixing tool 22 .

In the present invention, the fixing member 22 engaged with the welding tool holder 5 and the fixing portion 20 are not in flat surface contact but are locally in contact (point contact or line contact).

The joining tool holding portion 19 and the fixing portion 20 will be described with reference to FIGS. 3A to 4B.

FIG. 3A is a top view showing the configuration of the joining tool holding portion 19. FIG. FIG. 3B is a side view showing the configuration of the joining tool holding portion 19. As shown in FIG. 4A and 4B are diagrams showing the mortar-shaped fixing portion 20. FIG.

In the present invention, the shape of the fixing portion 20 is a mortar shape in which the side surface from the bottom surface portion 23 to the top portion 25 is not flat but sloped (slope portion 24). As shown in FIGS. 4A and 4B, it is made to have a conical shape or a hemispherical shape. As long as the side surface is a slope (slope portion 24), the top portion 25 may have a flat truncated cone shape other than the conical shape and the hemispherical shape. From the point of view of the working surface, conical or hemispherical shapes are preferred.

FIG. 5 shows the structure of the fixture 22, and FIGS. 6A to 6C show the shape of the distal end of the fixture 22. As shown in FIG.

The fixture 22 is composed of a tip portion 27 that enters the fixing portion 20 of the joining tool holder portion 19 , a body portion 26 having a screw thread structure, and a top portion 30 . The tip portion 27 has a conical shape, a truncated cone shape, or a hemispherical shape with a slope (slope portion 29 ) that narrows toward the top portion 30 .

The top portion 30 is configured to be tightened with a rotating tool such as a screwdriver or a wrench so as to be threadedly connected to a through hole 21 having a threaded structure provided in the joining tool holder 5 by rotating clockwise or counterclockwise.

A method for holding the fixing part 20 with the fixture 22 will be described in detail.

FIG. 7 is a diagram showing a state in which the fixture 22 and the fixing portion 20 are in contact with each other. In FIG. 7, the contact portion 33 is a joint portion between the front end portion 27 and the trunk portion 26 of the fixing member 22, and the slant portion of the fixing portion 20 is locally contacted (point contact or line contact). , the welding tool 6 is held in the welding tool holder 5 .

In this case, the contact portion 33 enters the fixed portion 20 deeper than the bottom portion of the fixed portion 20, and the contact portion 33 locally contacts (point contact or line contact) with the slope portion of the fixed portion 20. FIG. The center axis 32 of the bottom surface of the through hole 21 is slightly shifted toward the bottom surface of the inserting portion 18 of the joining tool holding portion 19 so that the center axis 32 of the top portion 25 of the fixing portion 20 does not coincide with the center axis 31 of the fixing portion 20 . The fixture 22 is threadedly connected to the through hole 21, and the fixture 22 is tightened with a rotating tool such as a screwdriver or a wrench so as to reach the maximum tightening torque.

As a result, when the maximum tightening torque is reached, the contact portion 33 presses the slope of the fixing portion 20 against the cylindrical bottom surface of the welding tool holding portion 19 to hold the welding tool 6 in the welding tool holder 5 . A clearance (gap) 34 is created on the side.

The center of the upper bottom surface of the through hole 21 is shifted from the center of the top portion 25 of the fixing portion 20 toward the cylindrical bottom surface of the joining tool holding portion 19. Conversely, the center of the upper bottom surface of the through hole 21 When the contact portion 33 is shifted from the center of the top of the fixed portion 20 to the side opposite to the bottom surface of the cylinder of the welding tool hold portion 19 , the contact portion 33 is located on the side of the shoulder portion 7 opposite to the bottom surface of the cylinder of the welding tool hold portion 19 . The contact portion locally contacts (point contact or line contact) with the slope portion, and a force acts in the direction of pulling out the welding tool holding portion 9 from the insertion portion 18 of the welding tool holder 5, which is not preferable.

Embodiment 2 A friction stir welding apparatus and a welding tool holding method according to Embodiment 2 of the present invention will be described with reference to FIG.

FIG. 8 is a diagram showing a state in which the fixture 22 and the fixing portion 20 of this embodiment are in contact with each other, and corresponds to a modification of the first embodiment (FIG. 7).

In this embodiment (FIG. 8), the sloped portion 29 of the tip portion 27 of the fixture 22 serves as a contact portion, and locally contacts (point contact or line contact) the outer peripheral portion of the bottom portion of the fixing portion 20. This case holds the welding tool 6 in the welding tool holder 5 .

In this case, unlike the first embodiment (FIG. 7), the tip 27 of the fixture 22 does not deeply enter the fixing portion 20, and the contact portion 33 locally contacts the outer peripheral portion of the bottom portion of the fixing portion 20. The maximum tightening torque is generated in the fixture 22 at the position (point contact or line contact).

Also in this case, the central portion 32 of the upper bottom surface of the through hole 21 must be shifted from the central portion 31 of the top portion of the fixing portion 20 toward the bottom surface of the joining tool holding portion 19 . The reason is the same as in the case of FIG.

The number of fixing portions 20 provided and the diameter of the upper bottom surface of the fixing tool 22 will be described. Usually, one fixed part 20 is arranged and held by the fixture 22 . However, when the material of the member to be joined 9 is hard or thick, it is necessary to hold it even more strongly. As a method for this, it is conceivable to increase the diameter of the upper bottom surface of the through hole 21 and the diameter of the trunk portion 26 of the fixture 22 .

However, if the diameter of the fixture 22 is increased, the strength of the welding tool holder 5 may be reduced, or there may be physical restrictions on dimensions, and there may be problems such as interference with the members that clamp the workpiece 9, and so on. When the holder 5 cannot be used, it is more rational to increase the number of fixtures 22 to hold the welding tool 6 instead of increasing the diameter of the fixtures 22 .

In this case, the arrangement positions of the first fixture 22 and the second fixture 22 are not particularly affected by the pitch angle. 120 degrees and 180 degrees are good.

In addition, the present invention is not limited to the above-described embodiments, and includes various modifications. For example, the above-described embodiments have been described in detail in order to explain the present invention in an easy-to-understand manner, and are not necessarily limited to those having all the described configurations. In addition, it is possible to replace part of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment. Moreover, it is possible to add, delete, or replace a part of the configuration of each embodiment with another configuration.

DESCRIPTION OF SYMBOLS 1... Friction stir welding apparatus, 2... Apparatus main body, 3... Z-axis vertical motion drive mechanism part, 4... Spindle support part, 5... Welding tool holder, 6... Welding tool, 7... Shoulder part, 8... Probe part (welding Pins), 9, 9a, 9b Members to be welded 10 Mounting table 11 Control unit (control device) 12 X-axis front-rear drive mechanism 13 X-axis front-rear drive motor 14 Spindle motor 15 ... Spindle holder, 16 ... Main shaft, 17 ... Z-axis vertical movement drive motor, 18 ... Insertion part, 19 ... Joining tool holder part, 20 ... (Conical shaped) fixing part, 21 ... Through hole, 22 ... Fixing tool (stopper) screw), 23 bottom portion, 24 slope portion, 25 top portion, 26 body portion, 27 front end portion, 28 bottom portion, 29 slope portion, 30 top portion, 31 center of fixing portion 20, 32 .

Claims (8)

A welding tool composed of a welding tool holding portion, a shoulder and a probe is rotated at a target rotational speed and inserted into a member to be welded to a target depth, and the welding tool is advanced while softening the insertion portion of the member to be welded and its vicinity. A friction stir welding apparatus for friction stir welding the members to be welded by
The fixing part is formed by at least one mortar-shaped recess provided at a predetermined position of the joining tool holding part by inserting the joining tool holding part into the insertion part of the joining tool holder, wherein the bottom part of the fixing part is Friction stir characterized in that the welding tool is held in the welding tool holder by locally contacting the contact part of the fixture locked to the welding tool holder with the circumference or the slope part of the fixing part. Welding equipment. The friction stir welding apparatus according to claim 1,
The welding tool is held in the welding tool holder by bringing the contact portion of the fixing tool into point contact with one point on the circumference of the bottom surface of the fixing portion or one point on the slope portion of the fixing portion. friction stir welding equipment. The friction stir welding apparatus according to claim 1,
A friction stir welding apparatus, wherein the welding tool is held in the welding tool holder by bringing the contact part of the fixture into line contact with the circumference of the bottom part of the fixing part or the slope part of the fixing part. The friction stir welding apparatus according to claim 1,
The fixture is a composite in which a conical, hemispherical, or truncated cone-shaped tip and a body having a screw thread structure on the side are combined,
It is arranged in the welding tool holder in a cylindrical shape having an upper bottom surface whose center is shifted toward the bottom surface of the insertion part of the welding tool holder with respect to the center of the bottom surface of the fixing part, and has a screw thread structure on the side part. A friction stir welding apparatus, characterized in that a screw thread of a body portion of the fixture is connected to the through-hole. The friction stir welding apparatus according to claim 4,
The top of the fixture passes through the through hole, and the fixture is adjusted so that the maximum tightening torque is reached at a position where the top of the distal end of the fixture does not contact the top of the fixing part of the joining tool holder. head is tightened clockwise or counterclockwise with a rotating tool such as a screwdriver or a wrench. The friction stir welding apparatus according to claim 5,
Either a joint portion indicating a joining portion between the tip portion of the fixture and the trunk portion or a sloped portion of the tip portion of the fixture serves as the contact portion,
When the joint portion serves as the contact portion, the contact portion makes point contact with the slope portion of the fixed portion,
A friction stir welding apparatus according to claim 1, wherein, when the inclined surface portion of the tip portion of the fixture serves as the contact portion, the contact portion is in point contact with the outer peripheral portion of the bottom surface portion of the fixing portion. The friction stir welding apparatus according to claim 4,
The number of fixing portions provided, the diameter of the through-hole, and the diameter of the fixture, depending on the welding conditions including the material and thickness of the members to be welded and/or the working environment including the clamp member for fixing the members to be welded. A friction stir welding apparatus characterized by determining A welding tool holding method for fixing a welding tool to a welding tool holder with a fixture, comprising:
inserting the joining tool holding part into the insertion part of the joining tool holder;
In the fixing part formed by at least one mortar-shaped depression provided at a predetermined position of the joining tool holding part, the contact part of the fixing tool is attached to the circumference of the bottom part of the fixing part or the slope part of the fixing part. A method for holding a welding tool, characterized in that the welding tool is held in the welding tool holder by means of a fixture that engages the welding tool with the welding tool holder by locally contacting the welding tool.

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