Friction stir welding tool

Abstract

To provide a friction stir welding tool.SOLUTION: A friction stir welding tool includes a welding probe 20, a welding probe holder 10, and a bolt 30. The welding probe holder 10 has a shoulder part 11 which rubs against two work-pieces during friction stir welding, an open hole 12, and a screw hole 13. The open hole 12 is opened so as to penetrate the welding probe holder 10 therethrough along an axial direction D11 of a rotation axis, the screw hole 13 is opened so as to communicate with the open hole 12 along a radial direction orthogonal to the axial direction D11 from an external surface of the welding probe holder 10, and the welding probe 20 has a fixed part 21, and a stirring part 22. The fixed part 21 is inserted in the opening on the shoulder part 11 side of the open hole 12, the stirring part 22 projects from an opening on the shoulder part 11 side so as to penetrate a gap between two work-pieces and to be capable of stirring, and the bolt 30 is inserted in the screw hole 13 so as to contact the fixed part 21.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a joining tool, and more particularly to a friction stir welding tool. [Background technology]

[0002] Friction stir welding is a joining method in which a joining tool is inserted between two components and rotated to generate frictional heat to soften the components, and the softened components are then stirred and joined by the rotation.

[0003] The welding tools currently used in friction stir welding include those formed as a single unit and the two-part friction stir welding tool shown in Patent Document 1. Furthermore, the quality of friction stir welding is related to the processing temperature during welding. Therefore, one of the challenges facing engineers in this technical field is how to measure the processing temperature during the welding process. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 10-249552 Summary of the Invention [Problem to be solved by the invention]

[0005] SUMMARY OF THE INVENTION It is an object of the present invention to provide a friction stir welding tool that overcomes at least one of the problems of the prior art. [Means for solving the problem]

[0006] The present invention provides a friction stir welding tool for joining two workpieces by rotation, a bonding probe, a bonding probe holder, and a bolt; the welding probe holder has a shoulder portion that rubs against the two workpieces during friction stir welding, a through hole, and a screw hole; the through-hole is opened so as to penetrate the bonded probe holder along the axial direction of the axis of rotation passing through a central portion of the shoulder portion, the screw hole is formed in a radial direction perpendicular to the axial direction from an outer surface of the bonded probe holder so as to communicate with the through hole; the joining probe has a fixing portion and a stirring portion, the fixing portion is inserted into an opening of the through hole on the shoulder portion side, the stirring portion protrudes from the opening on the shoulder portion side so as to penetrate into the gap between the two workpieces and stir them, The present invention provides a friction stir welding tool, wherein the bolt is threaded into the screw hole so as to contact the fixing portion. [Effects of the Invention]

[0007] The above-described friction stir welding tool provides a two-part friction stir welding tool that differs from conventional two-part friction stir welding tools. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a perspective view of an embodiment of a friction stir welding tool of the present invention. [Figure 2] FIG. 2 is an exploded view of the above embodiment. [Figure 3] FIG. 2 is a partial cross-sectional view of the embodiment. [Figure 4] FIG. 10 is a perspective view showing two members being processed by the joining device using the above embodiment. [Figure 5] FIG. 10 is a perspective view showing the joining apparatus using the above embodiment to process two other members. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0010] In order to more clearly describe the objectives, technical means, and advantages of the embodiments of the present invention, the following will clearly and completely describe the technical means in the embodiments of the present invention in combination with the accompanying drawings of the embodiments of the present invention. It should be apparent that the described embodiments are only some embodiments of the present invention, and not all embodiments. Generally, the components of the embodiments of the present invention depicted and shown in the accompanying drawings can be arranged and designed in various different configurations. Therefore, the detailed description of the embodiments of the present invention provided below in the accompanying drawings does not constitute any limitation on the protection scope of the present invention, but merely represents selected embodiments of the present invention.

[0011] Before describing the present invention in more detail, it should be noted that, where considered appropriate, reference numerals or terminal portions of reference numerals have been repeated among the figures to indicate corresponding or analogous elements, which may optionally have similar characteristics.

[0012] In describing the present invention, terms indicating orientations or positional relationships such as "upper," "lower," "inner," "outer," "left," "right," "front," "rear," "top," and "bottom" are used based on the orientations and positional relationships shown in the drawings or the orientations and positional relationships customarily assumed when using the product of the present invention, for the purpose of easier and clearer explanation, and are not intended to teach or suggest that the corresponding apparatus or device has a specific orientation, structure, operation, etc. in a specific orientation, and are not intended to be a limitation on the present invention.

[0013] The embodiment of the friction stir welding tool 1 of the present invention is suitable for use in conjunction with a welding apparatus M and for being placed in a tool holder 2 on the welding apparatus M, as shown in FIG.

[0014] The tool holder 2 is installed on the processing axis (not shown) of the joining device M, and is configured to be able to rotate the friction stir welding tool 1 installed on top of it, and friction stir welding processing is performed on two workpieces W by rotating the friction stir welding tool 1.

[0015] In this embodiment, the friction stir welding tool 1 of the present invention employs a two-part design as shown in FIGS. 1 to 5, and therefore the friction stir welding tool 1 of the present invention can also be called a two-part tool 3.

[0016] In this embodiment, as shown in FIG. 3 , the friction stir welding tool 1 includes a welding probe holder 10, a welding probe 20 inserted into the welding probe holder 10 along an axial direction D11 of the axis of rotation of the friction stir welding tool 1, a bolt 30 inserted into the welding probe holder 10 along a radial direction D12 perpendicular to the axial direction D11, a temperature detection probe 40 inserted into the welding probe holder 10 and the welding probe 20 and in contact with the welding probe 20 to detect the temperature of the welding probe 20, and a wireless signal transmitter 50 installed on the welding probe holder 10 and electrically connected to the temperature detection probe 40.

[0017] As shown in FIGS. 2 and 3, the joint probe holder 10 is tubular or cylindrical and hollow along the axial direction D11.

[0018] The joining probe holder 10 also has a shoulder portion 11 located on the bottom side and abutting against the two workpieces W in Figure 4 or Figure 5 to rub against the two workpieces W during the friction stir welding process, a through hole 12 drilled to pass through the joining probe holder 10 along the axial direction D11, a screw hole 13 drilled to pass through along the radial direction D12 to communicate with the through hole 12, and an adjustment screw 14 screwed into the through hole 12 from the top side.

[0019] The through hole 12 is opened to extend along an axial direction D11 that passes through the center of the shoulder portion 11 from the center of the shoulder portion 11, i.e., the axis of rotation of the friction stir welding tool 1 passes through the center of the shoulder portion 11.

[0020] Furthermore, in the through hole 12, as shown in FIG. 3, the portion close to the shoulder portion 11 is a flat portion 121 defined by a wall surface with no irregularities (i.e., no threads formed on the wall surface), and the portion farther from the shoulder portion 11 than the flat portion 121 is a screw hole portion 122 defined by a wall surface on which threads are formed.

[0021] As shown in FIG. 3, the flat portion 121 extends from the opening of the through-hole 12 on the shoulder portion 11 side so as to directly communicate with the screw hole 13.

[0022] The adjusting screw 14 is threaded into the screw hole portion 122 .

[0023] In this embodiment, the through-hole 12 is entirely made up of the screw hole portion 122 except for the flat portion 121, and the flat portion 121 and the screw hole portion 122 are directly connected to each other.

[0024] The joint probe 20 is inserted into the joint probe holder 10 along the axial direction D11, and has a fixing portion 21 and a stirring portion 22 that are integrally connected to each other above and below.

[0025] The fixing portion 21 is formed in a cylindrical shape, and is inserted into a flat portion 121 at the opening of the through-hole 12 on the shoulder portion 11 side, with the top end abutting the adjusting screw 14. As a result, the depth to which the fixing portion 21 is inserted into the through-hole 12 can be adjusted by the degree to which the adjusting screw 14 is screwed into the through-hole 12. In other words, the fixing portion 21 is configured to be insertable into the screw hole portion 122, and the adjusting screw 14 is configured to be able to enter the flat portion 121.

[0026] The stirring portion 22 is formed in a truncated cone shape, and extends downward from the bottom end of the fixing portion 21 and protrudes from the opening on the shoulder portion 11 side so that it can penetrate into the gap between the two workpieces W and stir and join the two workpieces W.

[0027] Taking into consideration the characteristics of the workpiece W, such as its melting point, the materials constituting the bonding probe holder 10 and the bonding probe 20 may be, for example, ceramic, polycrystalline cubic boron nitride (PCBN), tungsten rhenium alloy, carbon steel, high tensile steel, titanium alloy, metallic titanium, or copper alloy.

[0028] In addition, in the friction stir welding process, one of the functions of the joining probe holder 10 is to generate frictional heat, and one of the functions of the joining probe 20 is to stir the workpiece material that has softened and become capable of plastic flow.

[0029] That is, the functions of the bonded probe holder 10 and the bonded probe 20 are different. Therefore, the bonded probe holder 10 and the bonded probe 20 may be made of the same material or different materials, taking into consideration both functionality and cost.

[0030] The bolt 30 extends in the radial direction D12 and is threaded into the threaded hole 13 of the bonded probe holder 10, and abuts against the fixing portion 21, thereby holding the bonded probe 20 in a predetermined position on the bonded probe holder 10.

[0031] The temperature detection probe 40 is in contact with the bonding probe 20 to detect the working temperature of the bonding probe 20 .

[0032] As shown in FIG. 3, the joining probe 20 is provided with a temperature detection axial hole 23 extending along the axial direction D11 and a temperature detection radial hole 24 extending along the radial direction D12 so as to communicate with the temperature detection axial hole 23.

[0033] As shown in FIG. 3, the bonded probe holder 10 is provided with a temperature detection hole 15 extending along the radial direction D12 so as to correspond to and communicate with the temperature detection radial hole 24.

[0034] The temperature sensing radial hole 24 of the junction probe 20 has one end directly communicating with the temperature sensing hole 15 and the other end directly communicating with the temperature sensing axial hole 23 .

[0035] The temperature detection probe 40 is installed so as to be inserted into the temperature detection axial hole 23, the temperature detection radial hole 24, and the temperature detection hole 15. In this way, the temperature detection probe 40 detects whether the processing temperature of the bonding probe 20 is within a predetermined processing temperature range.

[0036] The wireless signal transmitter 50 is installed in the joint probe holder 10 and electrically connected to the temperature detection probe 40, and transmits the temperature detected by the temperature detection probe 40 to an external control device or computing system.

[0037] The wireless signal transmitter 50 is installed on the outer surface of the bonded probe holder 10 as shown in FIGS. 1 and 2, but is not limited thereto.

[0038] In this embodiment, as shown in FIG. 3, in addition to the above, another set of temperature detection probe 40A and wireless signal transmitter 50A is installed, and the joining probe holder 10 has a shoulder temperature detection hole 16 extending obliquely upward and downward.

[0039] The shoulder temperature detection hole 16 extends from the outer surface of the bonding probe holder 10 to a position close to the shoulder 11 so as to be recessed in order to accurately detect the processing temperature of the shoulder 11 .

[0040] The temperature detection probe 40A is inserted into the shoulder temperature detection hole 16 and is electrically connected to the wireless signal transmitter 50A, which detects the processing temperature of the shoulder 11 and transmits the detected temperature to an external control device or computing system via the wireless signal transmitter 50A.

[0041] As shown in FIGS. 4 and 5, the above-described friction stir welding process involves moving the friction stir welding tool 1 along a welding path P to perform friction stir welding on two workpieces W.

[0042] Among these, the real-time feed rate, which is the speed at which the friction stir welding tool 1 moves along the welding path P at the current position during the friction stir welding process, is determined by the following formula.

number

[0043] FR o is the speed (initial speed) at which the friction stir welding tool 1 moves along the welding path P at the starting point of the welding path P.

[0044] D is the distance that the friction stir welding tool 1 has already moved along the welding path P from the starting point of the welding path P.

[0045] L is the total path length of the joint path P.

[0046] α is a parameter set according to the joining characteristics of the friction stir welding process.

[0047] As the friction stir welding process progresses, the total amount of heat energy provided to the two workpieces W gradually accumulates, and many of the workpieces W have low thermal conductivity. Therefore, when the real-time feed rate is determined using the above method, the closer the friction stir welding process is to completion, the faster the real-time feed rate becomes. This has three advantages: (1) the processing time for the friction stir welding process is shortened, (2) the energy used in the friction stir welding process can be saved, and (3) a decrease in welding quality due to excessive temperature rise in areas of the workpieces W in the latter half of the welding path P can be avoided.

[0048] Furthermore, the heat transfer coefficient of the workpiece W varies depending on the material of the workpiece W. Therefore, the above-mentioned joining characteristics include the heat transfer coefficient of the workpiece W. Specifically, the higher the heat transfer coefficient of the workpiece W, the higher the set parameter α becomes, and similarly, the lower the heat transfer coefficient of the workpiece W, the lower the set parameter α becomes.

[0049] In addition to the heat transfer coefficient of the workpieces W, factors that affect the temperature rise of each workpiece W during friction stir welding processing include the following: For example, there is a large difference in the path length of the joining path P shown in Figures 4 and 5; the path length of the joining path P shown in Figure 4 is short, while the path length of the joining path P shown in Figure 5 is clearly long. Therefore, it can be expected that the total amount of thermal energy provided to the workpieces W shown in Figure 5 during the entire friction stir welding process is higher than the total amount of thermal energy provided to the workpieces W shown in Figure 4, and therefore the above-mentioned joining characteristics can further include the ratio of the volume of the friction-stirred area in each workpiece W to the total volume of each workpiece W (hereinafter referred to as the "joining volume ratio").

[0050] Specifically, since the joining volume ratio of the workpiece W in Figure 5 is higher than the joining volume ratio of the workpiece W in Figure 4, the parameter α set when friction stir welding the workpiece W in Figure 5 should be higher than the parameter α set when friction stir welding the workpiece W in Figure 4.

[0051] In other embodiments, the above welding characteristics may further include factors such as the rotational speed of the friction stir welding tool 1 and the upset force that the friction stir welding tool 1 applies to each workpiece W, but are not limited to these.

[0052] As described above, the friction stir welding tool 1 of the present invention provides a two-part friction stir welding tool 1 that is different from conventional two-part friction stir welding tools.

[0053] The above-described embodiments are illustrative for explaining the principles and effects of the present invention, and are not intended to limit the present invention. Those skilled in the art may make slight changes or modifications to the above-described embodiments without departing from the spirit and scope of the present invention. Therefore, all changes and modifications made by those skilled in the art without departing from the gist of the present invention should be considered to fall within the scope of protection of the present invention. [Industrial Applicability]

[0054] The present invention provides a friction stir welding tool suitable for friction stir welding. [Explanation of symbols]

[0055] 1. Friction stir welding tool 2 Tool holder 3 Two-Part Tools 10 Bonded Probe Holder 11 Shoulder 12 Through holes 121 Flat area 122 Screw hole part 13 screw holes 14 Adjustment screw 15 Temperature detection hole 16 Shoulder temperature detection hole 20 Bonded Probe 21 Fixed part 22 Stirring section 23 Temperature sensing axial hole 24 Temperature sensing radial hole 30 volts 40, 40A temperature sensing probe 50, 50A Wireless Signal Transmitter D11 Axial direction D12 Radial M joining device P conjugation pathway double work

Claims

1. A friction stir welding tool for joining two workpieces by rotation, a bonding probe, a bonding probe holder, and a bolt; the welding probe holder has a shoulder portion that rubs against the two workpieces during a friction stir welding process, a through hole, and a screw hole; the through-hole is opened so as to penetrate the bonded probe holder along the axial direction of the axis of rotation passing through a central portion of the shoulder portion, the screw hole is formed in a radial direction perpendicular to the axial direction from an outer surface of the bonded probe holder so as to communicate with the through hole; the joining probe has a fixing portion and a stirring portion, the fixing portion is inserted into an opening of the through hole on the shoulder portion side, the stirring portion protrudes from the opening on the shoulder portion side so as to penetrate into the gap between the two workpieces and stir them, The friction stir welding tool, characterized in that the bolt is threaded into the screw hole so as to contact the fixing portion.

2. The friction stir welding tool according to claim 1 , further comprising a temperature sensing probe that contacts the welding probe and senses a temperature of the welding probe.

3. The friction stir welding tool of claim 2 , further comprising a wireless signal transmitter electrically connected to the temperature sensing probe.

4. The friction stir welding tool according to claim 3 , wherein the wireless signal transmitter is installed in the welding probe holder.

5. In the through hole, a portion close to the shoulder portion is a flat portion defined by a wall surface without irregularities, and a portion farther from the shoulder portion than the flat portion is a threaded hole portion defined by a wall surface on which a screw thread is formed, The bonded probe holder further includes an adjustment screw threaded into the screw hole portion, One end of the fixed portion of the joint probe abuts against the adjustment screw; The friction stir welding tool according to claim 1, wherein the depth to which the fixing portion is inserted into the through hole can be adjusted by the adjustment screw.

6. the joining probe is provided with a temperature detection axial hole extending along the axial direction, and a temperature detection radial hole extending along the radial direction so as to communicate with the temperature detection axial hole, the joining probe holder has a temperature detection hole extending along the radial direction so as to communicate with the temperature detection radial hole; The friction stir welding tool according to claim 2 , wherein the temperature sensing probe is installed so as to be inserted into the temperature sensing axial hole, the temperature sensing radial hole, and the temperature sensing hole.

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