Friction stir joining tool, friction stir joining head, and friction stir joining device

Abstract

A friction stir welding jig (10) has a main body (11) attached to a spindle (4) of a machine tool (2), a work shaft (13) rotatably supported by the main body (11) and having an attachment portion (131) of a welding tool (20) at a front end, and a pair of pressing members (16) supported by the main body (11) and disposed on both sides of the attachment portion (131). The pressing members (16) are formed of a disc-shaped elastic material and are rotatably supported about a rotation axis (A) crossing the rotation axis R of the work shaft (13) obliquely.

Description

TECHNICAL FIELD

[0001] The present application relates to a friction stir joining tool, a friction stir joining head, and a friction stir joining device. BACKGROUND

[0002] Friction stir joining is used as a joining method of materials.

[0003] In friction stir joining, in order to obtain sufficient friction heat, high torque is required in the rotation of the joining tool, and a dedicated friction stir joining device has been used in the past. On the other hand, as long as high torque can be obtained, a general-purpose machine tool can be used as a friction stir joining device (see Patent Document 1).

[0004] In the above-described Patent Document 1, the rotation axis of the joining tool is arranged vertically with respect to the surface of the workpiece to be joined. In contrast, by tilting the rotation axis of the joining tool, adopting a posture in which the front end side is displaced to the front side of the moving direction, it is possible to improve the entry into the workpiece and the retention of the softened material.

[0005] Such a tilted posture of the rotation axis of the joining tool is achieved not only by providing a tilting mechanism including a bent joint on a friction stir joining head including the joining tool or a friction stir joining tool capable of attaching the joining tool, but also by adjusting the main shaft of the machine tool to a tilted state.

[0006] Including the above-described Patent Document 1, in the past friction stir joining, the joining lines of the workpieces to be joined to each other are straight lines, and the rotating joining tool is moved along the joining lines. In contrast, it is required to apply friction stir joining to more complex shapes, such as a joining line that is bent in the middle or a curved joining line, and the like. For this reason, it is required that not only the moving direction of the joining tool, but also the tilting direction of the joining tool can be easily changed.

[0007] In response to such a requirement, the present applicant has developed a friction stir joining tool having a main body attached to the main shaft of a machine tool, a machining shaft rotatably supported by the main body and capable of attaching a joining tool, and a rotation driving portion that rotationally drives the machining shaft, and using an air motor driven by air passing through the center from the main shaft as the rotation driving portion (Japanese Patent Application No. 2020-075490).

[0008] PRIOR ART DOCUMENTS

[0009] PATENT DOCUMENTS

[0010] Patent Document 1: Japanese Patent Application Publication No. 2017-127881 SUMMARY

[0011] PROBLEMS TO BE SOLVED BY THE INVENTION

[0012] In the case of using a general machine tool for friction stir joining, a workpiece is held flat along the table surface of the machine tool. However, the workpiece is deformed by heat generated at the time of joining, and there are cases where a portion along the joining line is raised, and if a step or the like occurs with respect to the other workpiece for joining, proper joining can not be performed.

[0013] For the raising of the workpiece, a pushing member that pushes the workpiece from the surface side (the side opposite the backstop member) of the workpiece can be considered, but in a general machine tool, it is difficult to add such a mechanism. Furthermore, in the case where the joining line is not a straight line but a variety of curved lines, or the like, it is more difficult to push the workpiece with a pushing member for a joining tool in advance.

[0014] On the other hand, in the case where the pushing member is a member that slides on the workpiece, there is a possibility that frictional resistance or scratching of the surface of the workpiece, or the like, will occur. Furthermore, in the case where the workpiece has a concave-convex along the joining line, there is a possibility that the pushing member will interfere with the concave-convex and movement will be hindered.

[0015] Because of such cases, a mechanism that is simple in construction, can adapt to a variety of joining, and can prevent the raising of the workpiece is required to be developed.

[0016] An object of the present application is to provide a friction stir joining tool, a friction stir joining head, and a friction stir joining device that are simple in construction, can adapt to a variety of joining, and can prevent the raising of a workpiece.

[0017] Means for solving the problem

[0018] The friction stir joining tool of the present application is characterized by having: a main body attached to a main shaft or a main shaft head of a machine tool; a machining shaft rotatably supported by the main body and having an attachment portion of a joining tool on the front end; and a pair of pushing members supported by the main body and disposed on both sides of the attachment portion, the pushing members being formed of a disc-shaped elastic material and being rotatably supported around a rotation axis that is obliquely intersected with the rotation axis of the machining shaft.

[0019] In such a friction stir joining tool of the present application, by attaching the joining tool to the attachment portion and rotating the machining shaft, friction stir joining of a workpiece can be performed. At this time, by pushing the pair of pushing members against the workpiece, raising of the workpiece on both sides of the joining tool can be prevented.

[0020] Since the pushing members are formed in a disc shape and are rotatably supported, when the joining tool moves with respect to the workpiece, the pushing members can follow by turning on the workpiece. Thus, friction against the workpiece can be avoided, even if there is a concave-convex on the workpiece, the pushing members can pass over, and the workpiece can be pushed in a stable state at all times.

[0021] Further, since the pushing member is formed of an elastic material, and the rotating shaft is arranged obliquely with respect to the machining shaft, i.e., obliquely with respect to the workpiece surface, a stable pushing force can be always applied to the workpiece by elastically deforming the pushing member by the pushing force when pushing against the workpiece.

[0022] In the friction stir joining tool of the present application, it is preferable that the above-mentioned main body be attached to the above-mentioned main shaft; and that a rotation driving portion for rotationally driving the above-mentioned machining shaft be provided on the above-mentioned main body.

[0023] In such a friction stir joining tool of the present application, since the main body is attached to the main shaft, the orientation of the inclination of the main body or the joining tool can be freely changed by controlling the rotational angle position of the main shaft in the machine tool.

[0024] Thus, by inclining the rotating shaft of the joining tool so as to be in a posture in which the front end side thereof is displaced to the front side of the moving direction, the entry into the workpiece and the holding of the softened material can be improved.

[0025] Further, the main body can be attached to the main shaft head, and the machining shaft can be connected to the main shaft. In the case of a machine tool of multi-axis control, the orientation of the main body can be changed by controlling the orientation of the main shaft head.

[0026] In the friction stir joining tool of the present application, it is preferable that the above-mentioned rotation driving portion be an air motor that is rotated by air supplied through the axis of the above-mentioned main shaft.

[0027] In such a friction stir joining tool of the present application, by using air from the main shaft, the power source can be easily ensured without the need for the supply of external power or the like.

[0028] Further, as the rotation driving portion of the present application, an electric motor that is supplied with power from the main shaft head through a cable can be provided.

[0029] In the friction stir joining tool of the present application, it is preferable that the profile of the outer peripheral portion in the cross-sectional shape of the pushing member along the rotating shaft be in a circular arc shape.

[0030] In such a friction stir joining tool of the present application, when the pushing member is pushed obliquely with respect to the workpiece, even if the pushing member is elastically deformed by the pushing force, any portion of the circular arc shape is always in contact with the workpiece in the same state.

[0031] The friction stir joining head of the present application is characterized by comprising: the above-mentioned friction stir joining tool of the present application; and the above-mentioned joining tool attached to the above-mentioned friction stir joining tool.

[0032] In such a friction stir joining head of the present application, the same effects as those of the above-mentioned friction stir joining tool of the present application can be obtained.

[0033] The friction stir joining device of the present application is characterized by comprising the friction stir joining fitting of the present application described above, the joining tool attached to the friction stir joining fitting, and the machine tool to which the friction stir joining fitting is attached.

[0034] In such the present application, the same effects as the friction stir joining fitting of the present application described above can be obtained.

[0035] According to the present application, it is possible to provide a friction stir joining fitting, a friction stir joining head, and a friction stir joining device which are simple in construction, can be adapted to a variety of joining, and can prevent warping of a workpiece. BRIEF DESCRIPTION OF DRAWINGS

[0036] Figure 1 is a perspective view showing a friction stir joining device of a first embodiment of the present application.

[0037] Figure 2 is a perspective view showing a friction stir joining fitting of the first embodiment.

[0038] Figure 3 is a side view showing an attached state of the friction stir joining fitting of the first embodiment.

[0039] Figure 4 is a side view showing a friction stir joining fitting of a second embodiment of the present application. DETAILED DESCRIPTION

[0040] In Figures 1 to 3 the first embodiment of the present application is shown.

[0041] In Figure 1 the friction stir joining device 1 of the present embodiment is configured by attaching the friction stir joining fitting 10 and the general joining tool 20 for friction stir joining based on the present application to the general machine tool 2 having a longitudinal main shaft.

[0042] The machine tool 2 is provided with a worktable 3 to fix a workpiece 9, a main shaft 4 to which a tool can be attached on a front end, a main shaft head 5 to rotatably support the main shaft 4, and a moving mechanism 6 to move the main shaft head 5 to an arbitrary position.

[0043] The moving mechanism 6 has a slider 62 supported by a horizontal guide rod 61, and the main shaft head 5 is supported downward from the slider 62. Thus, by elevating the main shaft head 5 with respect to the slider 62, it is possible to move the front end of the main shaft 4 to a designated position in the Z-axis direction. Further, by moving the slider 62 along the guide rod 61, it is possible to move the front end of the main shaft 4 to a designated position in the X-axis direction.

[0044] The main shaft 4 has its rotation axis R set vertically (Z-axis direction), and is capable of rotating around the rotation axis R (C-axis direction) by a driving motor in the main shaft head 5, and is capable of stopping at a designated angular position.

[0045] The table 3 is capable of rotating around a vertical axis (C-axis direction) by a driving mechanism provided in the bed 7, and is capable of stopping at a designated angular position.

[0046] These table 3, main shaft 4, main shaft head 5, and moving mechanism 6 are each provided on the upper surface of the bed 7, and the entire body can be enclosed by an openable and closable cover 8.

[0047] On the main shaft 4, the joining tool 20 is attached via the friction stir joining fitting 10 based on the present application. Here, by attaching the joining tool 20 on the friction stir joining fitting 10, a friction stir joining head 19 of the present application is constituted.

[0048] In the Figure 2 , the friction stir joining fitting 10 has a main body 11 attached to the main shaft 4 of the machine tool 2, a machining shaft 13 rotatably supported by the main body 11 and having an attachment portion 131 of the joining tool 20 on the front end, a rotation driving portion 14 that rotationally drives the machining shaft 13, and a pair of push members 16 supported by the main body 11 and disposed on both sides of the attachment portion 131.

[0049] The main body 11 is capable of being attached to the main shaft 4 with a taper shank 12 based on the specifications, and has a central through-hole 121 along the axis, and central through air is capable of being supplied from the main shaft 4 to the central through-hole 121.

[0050] The rotation driving portion 14 is constituted by an air motor that is rotated by high-pressure air, is capable of rotationally driving the machining shaft 13 by being rotated by the central through air supplied from the main shaft 4 via the central through-hole 121.

[0051] The push members 16 are each formed of a disc-shaped elastic material, and are rotatably supported around a rotation axis A that is obliquely intersected with the rotation axis R of the machining shaft 13.

[0052] The outer peripheral portion 161 of the push member 16 has its radial cross-sectional shape profiled in a semicircular shape, i.e., a circular arc shape with a central angle of about 180 degrees.

[0053] In the main body 11, the rotation center of the machining shaft 13 is disposed at a slight angle of 0 to 5 degrees obliquely with respect to the rotation axis R of the main shaft 4.

[0054] The direction in which the rotation center of the machining shaft 13 is obliquely disposed is set to a direction orthogonal to the rotation axis A of each of the pair of push members 16 (a direction orthogonal to the drawing surface of the Figure 3 ).

[0055] In Figure 3 the present embodiment, when friction stir joining is performed using the friction stir joining tool 10, after the joining tool 20 is attached to the attachment portion 131, the friction stir joining tool 10 is attached to the spindle 4. Next, the center through-air is supplied from the spindle 4 via the center through-hole 121, the rotation driving portion 14 rotationally drives the machining shaft 13 and the joining tool 20, and brings the joining tool 20 close to the joining line WL of the joining portions Wl, W2 of the workpiece 9.

[0056] The rotating joining tool 20 is introduced to the joining line WL, and the pressing member 16 comes into contact with the surface of the workpiece 9. At the time of bringing the pressing member 16 into contact with the workpiece 9, the pressing member 16 exerts a sufficient pressing force to be elastically deformed to a state of being deflected (refer to the single-dotted line of FIG. 10). Figure 3

[0057] Here, the orientation of the friction stir joining tool 10 is adjusted by the spindle 4 so that the direction in which the machining shaft 13 is inclined follows the joining line WL. In this state, by moving the spindle 4 along the joining line WL, friction stir joining is performed by the joining tool 20 at the joining line WL. The pressing member 16 rotates on the joining portions Wl, W2 as the joining tool 20 moves while pressing the joining portions Wl, W2 of the workpiece 9 on both sides of the joining tool 20, thereby preventing the joining portions Wl, W2 from being lifted at the portions where the joining tool 20 performs friction stir joining.

[0058] According to such a present embodiment, the following effects can be obtained.

[0059] In the present embodiment, by attaching the joining tool 20 to the attachment portion 131 and rotating the machining shaft 13, friction stir joining can be performed on the workpiece 9. At this time, by pressing the pair of pressing members 16 against the workpiece 9, lifting of the joining portions Wl, W2 of the workpiece 9 can be prevented on both sides of the joining tool 20.

[0060] The pressing member 16 is formed in a disc shape and is rotatably supported, so that it can follow by rotating on the workpiece 9 when the joining tool 20 moves relative to the workpiece 9. Thus, friction against the workpiece 9 can be avoided, and even if there are irregularities on the workpiece 9, the workpiece 9 can be pressed over the irregularities in a stable state.

[0061] Further, the pressing member 16 is formed of an elastic material, and the rotation axis A is disposed obliquely with respect to the machining shaft 13, i.e., obliquely with respect to the surface of the workpiece 9, so that it is elastically deformed by the pressing force when pressed against the workpiece 9, and a stable pressing force can be exerted on the workpiece 9.

[0062] ​In the present embodiment, since the main body 11 is attached to the main shaft 4, the inclination direction of the main body 11 or the joining tool 20 can be freely changed by controlling the rotational angle position of the main shaft 4 in the machine tool 2.

[0063] Thus, by inclining the rotational axis R of the joining tool 20 and setting it to a posture in which the front end side thereof is displaced to the front side of the moving direction, the access to the workpiece 9 and the holding property of the softened material can be improved.

[0064] In the present embodiment, since the rotational driving portion 14 is set to an air motor, the power source can be easily ensured by using air from the main shaft 4 without the need for the supply of external power or the like.

[0065] In the present embodiment, since the outline of the outer peripheral portion 161 in the cross-sectional shape along the rotational axis A of the push member 16 is semicircular, when the push member 16 is obliquely pushed against the workpiece 9, even if the push member is elastically deformed by the pushing force, any portion of the circular arc shape can always be in contact with the workpiece 9 in the same state.

[0066] Figure 4 A second embodiment of the present application is shown in FIG. 8.

[0067] The present embodiment shares the basic structure with the above-described first embodiment, but differs in the air supply path to the rotational driving portion 14. Therefore, the repeated description of the shared parts with the first embodiment is omitted, and the different parts are described below.

[0068] In the above-described first embodiment, the central through-hole 121 is provided in the main body 11, and the rotational driving portion 14 is rotated by the central through air supplied from the main shaft 4.

[0069] In contrast, in the present embodiment, as shown in FIG. 8, the outer peripheral member 17 is attached to the outer periphery of the main body 11. Figure 4

[0070] The outer peripheral member 17 is rotatably attached to the outer periphery of the main body 11 about the rotational axis R, and can be connected to the main shaft head 5 through the extension member 171 and the sub-shaft 172.

[0071] The air passage is formed from the sub-shaft 173 toward the outer peripheral member 17, and air from the main shaft head 5 can be supplied. The air supply to the rotational driving portion 14 can be performed via the annular groove formed on the inner peripheral surface of the outer peripheral member 17 or the outer peripheral surface of the main body 11 between the outer peripheral member 17 and the main body 11.

[0072] ​In the present embodiment, the driving air of the rotary drive section 14 can be supplied from the spindle head 5. Therefore, in the case where the spindle 4 does not have a function of supplying the center through air, the air supply to the rotary drive section 14 is easily performed by forming the air supply pipe on the spindle head 5.

[0073] Further, by using the outer peripheral member 17, the orientation adjustment of the inclination of the main body 11 or the joining tool 20 by the spindle 4 can be freely performed since the main body 11 is rotatable with respect to the outer peripheral member 17 as long as the outer peripheral member 17 is merely fixed with respect to the spindle head 5.

[0074] In addition, the present application is not limited to the above-described embodiments, and modifications and the like within the scope of achieving the object of the present application are included in the present application.

[0075] In the above-described embodiment, the push member 16 is made of an elastic material in a disc shape, but can be a polygonal shape or can not be limited to a plate shape as long as it can rotate on the workpiece 9 when the joining tool 20 moves with respect to the workpiece 9, or can be a roller or the like in which the elastic member is formed in a cylindrical shape.

[0076] In the above-described embodiment, the push member 16 can also be in a posture in which the front side in the advancing direction is wider than the rear side. By being in such a posture, when the push member 16 rotates on the workpiece 9, a self-centering effect is generated, and the swing in the advancing direction of the joining tool 20 can be suppressed.

[0077] In the above-described embodiment, an air motor is used as the rotary drive section 14, but as the rotary drive section of the present application, an electric motor to which power is supplied from the spindle head 5 via a cable can also be used.

[0078] In the above-described embodiment, the structure in which the main body 11 is attached to the spindle 4 and the orientation change can be performed by the spindle 4 is made, but the main body 11 can also be attached to the spindle head 5. In this case, the machining shaft 13 can be connected to the spindle 4, and the joining tool 20 can be rotationally driven by the rotational force of the spindle 4. In this case, as long as the machine tool 2 is a multi-axis control, the orientation of the inclination of the main body 11 or the joining tool 20 can be changed by the control of the orientation of the spindle head 5.

[0079] Industrial Applicability

[0080] The present application can be used for a friction stir joining tool, a friction stir joining head, and a friction stir joining device.

[0081] Explanation of Reference Numerals

[0082] 1…friction stir welding device; 2…machine tool; 3…table; 4…spindle; 5…spindle head; 6…moving mechanism; 7…bed; 8…cover; 9…workpiece; 10…friction stir welding fitting; 11…main body; 12…tapered shank; 121…central through-hole; 13…processing shaft; 131…attachment portion; 14…rotary drive portion; 16…pushing member; 161…outer peripheral portion; 17…outer peripheral member; 171…elongated member; 172…sub-shank; 173…sub-shank; 19…friction stir welding head; 20…joining tool; 61…guide rod; 62…slide block; A…rotary axis of pushing member; R…rotary axis of processing shaft; W1, W2…joining portion; WL…joining line.

Claims

1. A friction stir joining tool comprising: a main body attached to a main shaft or a main shaft head of a machine tool; a processing shaft rotatably supported by the main body and having a joining tool attaching portion at a front end; and a pair of pressing members supported by the main body and disposed on both sides of the attaching portion.

2. The friction stir joining tool according to claim 1, wherein the main body is attached to the main shaft, and a rotation drive portion that rotationally drives the processing shaft is provided on the main body.

3. The friction stir joining tool according to claim 2, wherein the rotation drive portion is an air motor that is rotated by air supplied through a shaft center of the main shaft.

4. The friction stir joining tool according to any one of claims 1 to 3, wherein a profile of an outer peripheral portion in a cross-sectional shape of the pressing member along a rotation axis is in a circular arc shape.

5. A friction stir joining head comprising: the friction stir joining tool according to any one of claims 1 to 4; and a joining tool attached to the friction stir joining tool.

6. A friction stir joining apparatus comprising: the friction stir joining tool according to any one of claims 1 to 4; the joining tool attached to the friction stir joining tool; and a machine tool to which the friction stir joining tool is attached. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

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