JP5187886B2 - Protrusion formation by friction welding - Google Patents

Description

  The present invention relates to the formation of protrusions by friction welding.

Aluminum alloy and magnesium alloy thin plates are used for housings and the like for the purpose of reducing the weight of mobile devices such as notebook computers and mobile phones. This casing needs to be provided with a protrusion for assembling or mounting a substrate, a motor, etc. on the housing. Conventionally, a forging method has been employed exclusively when forming these protrusions. This method uses the characteristics of plastic processing of a material using a large machine and requires a complicated operation. For example, in the formation of the convex portion described in Patent Document 1 (Japanese Patent Laid-Open No. 2-6034), the plastic flow in the length direction and the plate thickness direction is caused by the punch side convex portion eccentric from the position facing the concave portion of the die. And a convex portion having a predetermined shape is formed on the base plate material. According to this method, there is a problem that a concave portion that is not necessary is formed on the opposite side of the convex portion as in the case of the convex portion, and the Nikkei BP “Nikkei Mechanical” 2000.10. no. According to No. 553, pages 70-71 (Non-patent Document 1), when a magnesium alloy is extruded and forged, a flow pattern is generated, which causes problems in the appearance quality of the surface, especially when a high boss is formed. The problem is pointed out that the other side of the boss is recessed.
From these, by pressing the plate material around the convex portion to be formed, or by pressing the protrusion provided on the back surface of the convex portion to be further formed, a part of the base plate material is directed toward the convex portion to be formed. A projecting part is formed by plastic flow (Patent Document 2, Japanese Patent Application Laid-Open No. 2002-273540). A magnesium alloy component having a step of forming a projecting part by applying a load in the thickness direction to a magnesium alloy sheet. In the manufacturing method, the fluidity A of the alloy material in the vicinity of the region where the projections on the surface of the plate material are to be formed is controlled to be larger than the fluidity B of the alloy material in the vicinity of the back surface (Patent Document 3) It has been pointed out that various operations such as open 2004-337935) are necessary.
Although it can be understood that plastic fluidity is used in the above method, various complicated fine operations are required to use plastic flow, and even if fine operations are performed, the problem is still completely solved. Therefore, there is a need for a protruding portion and a method for forming the protruding portion that are different from conventional methods.

The following methods are considered as candidates other than the forging method in forming the protrusions by utilizing the plastic fluidity of the material when forming the protrusions using the material.
In the case of using stud welding, there are problems such as dents on the surface of the housing and thermal effects, and it is considered difficult to eliminate them, which is not an effective means at this stage.
In the friction welding method, it is necessary to adjust the temperature and rotational speed of the friction surface itself (Patent Document 5, Japanese Patent Publication No. 52-11294, etc.), and if a fin or the like is attached to the plate state by friction welding, In consideration of positioning or the like, the vibration means is employed (Patent Document 6, Japanese Patent Laid-Open No. 11-340392), and pressure adjustment at the time of press-fitting is required (Patent Document 7, Japanese Patent Laid-Open No. 2006-255749, Patent Document 8) No. 187778, Patent Document 9 and Japanese Patent Application Laid-Open No. 2007-105735), and a protrusion formed by a single material having a strength of a portion joined by friction welding of the protrusion. Whether the same level of strength can be maintained is a problem. This is not an effective measure.
The friction welding process is usually used to utilize the fact that a rotating solid cylindrical body is brought into contact with a plate material to form a recessed portion in the plate material, and the material around the recessed portion is melted and softened. There is no example used for the formation of the protrusion. The plastic flow caused by melting and softening the periphery of the dent by the rotating solid cylindrical body works effectively on the formation of the dent, but there is an application example that this method forms a projection immediately. I can't. In the friction welding process, the rotating probe is deformed by moving the surface of the plate (Japanese Patent Application Laid-Open No. 2004-74255, Japanese Patent Application Laid-Open No. 2005-118877) and does not move. In some cases, the specific part of the material is simply kept in a molten state (Japanese Patent Application Laid-Open No. 2005-305480).
In the conventional method, it cannot be expected that the protrusion is formed simply by the friction welding process of the metal plate.
JP-A-2-6034 JP 2002-273540 A JP 2004-337935 A JP 2004-337935 A Japanese Patent Publication No.52-11294 JP 11-340392 A JP 2006-255749 A JP 2006-187778 A JP 2007-105735 A JP 2004-74255 A JP 2005-118877 A JP 2005-305480 A "Nikkei Mechanical" 2000.10. no. 553, pp. 70-71

  The problem to be solved by the present invention is to provide a novel shaped protrusion obtained by friction welding and a novel manufacturing method of the novel shaped protrusion.

In order to solve the above-mentioned problems, the present inventors have been able to solve the above-mentioned problems by applying means that have not been used in the conventional method. Specifically, it is as follows.
(1) In the friction welding process, the plate material surface is moved by the rotating solid probe, and the outside of the probe is plastically deformed by friction, thereby performing processing such as welding. When the solid probe is rotated at one point to perform friction welding processing and penetrates into the plate material, the plate in contact with the outside of the probe can be melted to give plastic flow to the plate material.
The present inventors are not solid. When the hollow cylindrical tool or the stepped hollow cylindrical tool is rotated while being pressed from the surface of the plate material toward the inner surface, the tool is gradually rotated and the plate material is gradually rotated. While the outer plates of these tools melted, the plates in the hollow cylindrical portion of these tools also melted and caused plastic flow, and the molten plate was raised inside the hollow cylindrical portion of the tool. When the tool reaches the bottom surface, the rotation is stopped, and the raised part inside the hollow cylindrical part is separated from these tools and cooled, so that a protrusion with a new shape that was not expected in the prior art Can be formed.
When a single plate material is used, the protrusion is hollow, the top on the outside of the protrusion is relatively flat, can be perforated, and has a side wall. The bottom is open.
If there are two plates to be used, when the penetration of the tool is terminated when it reaches the bottom surface of the upper plate, the upper plate is deformed into a hollow cylindrical shape forming the top and side walls, When the hollow cylindrical shape is fixed to the lower plate by the friction welding, a protrusion having a new shape having a bottom can be formed.
As a result of the top of any protrusion rising along the inner side of the hollow cylindrical tool, the outer portion of the top is formed as a ring-shaped portion.
When such a protruding portion is formed by drawing, such a portion does not exist, and the shape of the protruding portion is not conventionally known. In use, a smooth shape can be achieved when the outer shape is deemed inappropriate for use. If the height is not suitable, it can be cut into an appropriate length for use.
The protrusion part by one board to be used can be used as a fixing means by a screw by making a hole in the top part and attaching a screw thread.
The projecting portion with two plates used can be used as a fixing means by a screw by making a hole in the top and attaching a screw thread, and can also be used by cutting a screw thread on the outside.
As a result, this casing can be used as a projection for attaching the instrument to the assembly or the casing.
(2) Specifically, it is as follows.
(A) Formation and manufacturing method of new protrusions by friction welding process The surface of a plate (magnesium alloy plate, aluminum alloy plate, copper plate, etc.) is rubbed with a hollow cylindrical tool or a stepped hollow cylindrical tool rotating at high speed. Then, by intruding to the bottom surface of the plate, the plate portion is raised inside the hollow cylindrical portion of the tool, and when the tool reaches the bottom surface, the rotation is stopped, and the raised portion inside the hollow cylindrical portion is When these are separated from the tool and cooled, a protrusion having a new shape (FIG. 4), which was not expected in the prior art, can be obtained. The obtained protrusion has a relatively flat top and a hollow cylindrical shape having a side wall.
The rising height is equal to or less than the height inside the hollow cylindrical portion, and the outer diameter of the protrusion is slightly shorter than the inner diameter of the hollow cylindrical tool. There is an annularly raised portion along the outside of the top. Such a portion does not exist when molding is performed by drawing.
The external shape and cross-sectional shape of the protrusions differ depending on the shape of the hollow cylindrical tool used and the stepped hollow cylindrical tool.
(B) Method of forming and manufacturing protrusion having novel bottom by friction welding process The upper plate stacked in two sheets is a plate selected from a magnesium alloy plate, an aluminum alloy plate or a copper plate, and the lower plate Is a plate material selected from a magnesium alloy plate, an aluminum alloy plate, a copper plate, an aluminum plate or an iron plate (a material different from the first one can be used), and the surface of the upper plate is formed in a hollow cylindrical shape. When a tool or a stepped hollow cylindrical tool is rotated at high speed and friction-welded and enters, the upper plate part rises into the hollow cylindrical part of the hollow cylindrical tool, and the upper plate turns into the lower plate. A novel shape protrusion (FIGS. 6 to 8) having a friction welded shape can be obtained. The obtained protrusion part is hollow, and the outer part of the top part has an annularly raised part. In the case of forming by drawing, such a portion does not exist and has a bottom portion, and a structure of this shape is not conventionally known. In use, a smooth shape can be achieved when the outer shape is deemed inappropriate for use. If the height is not suitable, it can be cut into an appropriate length for use.
The height of the protrusion is equal to or less than the inner height of the cylindrical tool, and the outer diameter of the protrusion is slightly shorter than the inner diameter of the hollow cylindrical tool. The external shape and cross-sectional shape of the protrusions differ depending on the cut surface of the hollow cylindrical tool used.
The external shape and cross-sectional shape of the protrusions differ depending on the shape of the hollow cylindrical tool or stepped hollow cylindrical tool used.

According to the present invention, (1) when the surface of a single plate (selected from a magnesium alloy plate, an aluminum alloy plate or a copper plate) is friction-welded with a hollow cylindrical tool or a stepped hollow cylindrical tool at high speed rotation, A plate rises in the hollow cylindrical portion of the tool, and a projection having a novel shape can be obtained. The shape of this protrusion is hollow, the top is relatively flat, and a hole can be drilled.
Further, according to the present invention, the upper side of a two-plate (the upper side is selected from a magnesium alloy plate, an aluminum alloy plate or a copper plate, and the lower side is selected from a magnesium alloy plate, an aluminum alloy plate, a copper plate, an aluminum plate or an iron plate) When a hollow cylindrical tool or a stepped hollow cylindrical tool is friction-welded at a high speed on the surface of the plate, the plate portion rises in the hollow cylindrical portion of the tool to form a protrusion having a new shape. The shape of this protrusion is hollow, the top is relatively flat, and a new shape of protrusion with the lower plate pressed against the bottom can be obtained.
The protrusion provides a fixing means that can be screwed.

(A) Protrusions formed by friction welding process and manufacturing method thereof Friction by a hollow cylindrical tool or a stepped hollow cylindrical tool rotating at a high speed on the surface of a single plate selected from a magnesium alloy plate, an aluminum alloy plate or a copper plate Pressure-treating, by allowing a hollow cylindrical tool or a stepped hollow cylindrical tool to enter the plate, the plate inside the hollow cylindrical portion of the tool is in a molten state and raised to the inside of the hollow cylindrical portion, When the tool reaches the bottom surface of the plate, the rotation is stopped, and the raised part inside the hollow cylindrical portion is separated from these tools and cooled, so that a plate selected from a magnesium alloy plate, an aluminum alloy plate and a copper plate is obtained. It is raised and a side wall part and a top part are formed, and the projection part which is a hollow cylinder shape can be obtained.

The projection forming apparatus of the present invention is as follows.
A hollow cylindrical tool or a stepped hollow cylinder via an attachment means at the tip of the main shaft of the friction welding / moving means by a rotational drive that can move in the propulsion direction while being rotatable and can move in the propulsion direction while rotating A plate-shaped tool is attached, and the surface of the plate selected from a magnesium alloy plate, an aluminum alloy plate or a copper plate is friction-welded with a hollow cylindrical tool or a stepped hollow cylindrical tool that rotates at high speed, and penetrates into the plate. By intruding, the plate inside the hollow cylindrical portion of the tool is in a state of rising in the hollow cylindrical portion inside in a molten state, forming a hollow column having a top portion and a side wall portion, and when the tool reaches the bottom surface, The apparatus is a projection forming device that forms a projection by separating the hollow cylinder from the tool by stopping the rotation of the tool and cooling the hollow cylinder from the tool.
FIG. 1 is an overall view of an apparatus for performing a friction welding process A with a hollow cylindrical tool of the present invention.
A column 7 is provided on the support base 8 of the friction stir processing apparatus so as to extend upward. The plate member 4 is fixed to the upper surface of the support base 8 by clamping means (not shown). The plate material is selected from a magnesium alloy plate, an aluminum alloy plate, or a copper plate. The column 7 is provided with a pressure-contact propulsion / rotation drive motor 1 that can rotate and move in the propulsion direction. A chuck which is the attaching means 5 is provided at the tip of the main shaft 9.
A hollow cylindrical tool or a stepped hollow cylindrical tool via a mounting means at the tip of the main shaft of the friction welding / moving motor 1 which becomes a friction welding / moving means by a rotational drive that can rotate and move in the propulsion direction. Is attached, and the surface of the plate material 4 is friction-welded with the hollow cylindrical tool or the stepped hollow cylindrical tool 3 to enter the plate 4 and melt the plate material inside the hollow cylindrical portion of the tool. When the plate inside the hollow cylindrical portion of the tool is in a molten state and swelled inside the hollow cylindrical portion, a hollow column 6 having a top portion and a side wall portion is formed, and when the tool reaches the bottom surface, the tool rotates. The hollow cylinder is pulled away from these tools and cooled, and the desired material selected from a single magnesium alloy plate, aluminum alloy plate and copper plate is raised to form a side wall portion and a top portion. Projections by the plate having a columnar shape can be obtained.

  The plate material 4 to be used is selected from a magnesium alloy plate, an aluminum alloy plate, or a copper plate. The plate 4 has a lower melting point and a higher coefficient of thermal expansion than the material constituting the hollow cylindrical tool or the stepped hollow cylindrical tool. The thickness of the plate material can be determined as appropriate. In general, it may be a thin plate, and is usually 0.3 mm or more, and those in the range of about 2 mm are used. In the embodiment, the one of 1.4 mm is cited.

If the above plate material is used for the hollow cylindrical tool or the stepped hollow cylindrical tool 3, one made of SUS304 stainless steel can be used. What is necessary is just to determine according to the material to be used. These tools 3 can be used as long as they have a higher melting point and a smaller coefficient of thermal expansion than the plate material 4.
A hollow cylindrical tool and a stepped hollow cylindrical tool are shown in FIG.
The inner diameter of the hollow cylindrical tool can be appropriately determined according to the outer diameter of the protrusion to be formed. Specifically, those having many shapes such as an outer diameter of 15 mm, an inner diameter of 10 mm, an outer diameter of 8 mm, an inner diameter of 5 mm; an outer diameter of 6 mm, an inner diameter of 3 mm; an outer diameter of 6 mm, and an inner diameter of 3 mm can be appropriately selected and used. . The maximum outer diameter is about 20 mm and the inner diameter is about 15 mm. The minimum outer diameter is about 5 mm and the inner diameter is about 3 mm.
The end of the hollow cylindrical tool or the stepped hollow cylindrical tool 3 can be of various shapes (FIG. 2). The shape of the protrusion 6 formed in accordance with this shape also changes.
The processing (friction welding process) conditions are determined by the shape of the hollow cylindrical tool, the number of revolutions, the pressure applied to the plate material, and the processing time.

The rotational speed of the hollow cylindrical tool 3 may be 5000 rpm or more, and 8000 to 10,000 rpm is adopted. Of course, it may be 10,000 rpm or more, and is determined by the apparatus used. According to the experiments by the inventors, the speed of about 50000 rpm has been confirmed.
The friction pressure applied to the plate material by the hollow cylindrical tool or the stepped hollow cylindrical tool 3 is sufficient to be 15 MPa or more, and in the examples, the case of 30 MPa is cited. The upper limit is determined by the device used. There is no need to raise it unnecessarily.
The peripheral speed may be about 150 m / min.

  When the surface of a single plate is friction-welded with a hollow cylindrical tool or a stepped hollow cylindrical tool 3 at high speed and the tool 3 is inserted into the plate, the plate is placed inside the hollow cylindrical portion of these tools. The height that rises and rises into the hollow cylindrical portion is generally about 5 mm to 7 mm (about 7 mm has been confirmed). The height of the hollow cylindrical part of the hollow cylindrical tool needs to be higher than this height. If the height is shorter than this, there will be no place to go out after the climax, and trouble will occur. The height of the resulting protrusion is lower than this height because the protrusion is cooled.

The outer shape of the protruding portion is the same shape as when a hollow cylindrical tool is copied, and the rubbing trace from the hollow rotating tool remains on the outer periphery of the protruding portion. On the outer periphery of the tip of the protrusion, bulging by the flash is recognized (a portion swelled in an annular shape is recognized along the outer side of the top). It is observed that the inside of the protrusion has a shape in which a plate material is taken into the inside, is a hollow cylindrical shape, and is hollow at the bottom.
As shown in FIG. 4, the outer diameter of the projecting portion of the hollow cylindrical shape is approximately 10 mm, and the height of the projecting portion is close to 7 mm. The height of the outer shape of the protrusion is high with respect to the outer diameter of the protrusion, and the shape is abrupt (it is considered that such a shape cannot be formed by deep drawing or the like). A flat part is seen at the top. Similarly, FIG. 6 shows a hollow cylindrical shape.
There is a flat part at the top, and a hole can be made. A screw thread can be provided and can be used to screw a housing or the like.
The resulting compressive strength of the protrusion can withstand screwing. A wide range of uses can be considered as means for screwing the housing.

(B) Novel protrusion by friction welding and manufacturing method thereof The upper plate stacked in two is a plate selected from a magnesium alloy plate, an aluminum alloy plate or a copper plate, and the lower plate is a magnesium alloy plate , An aluminum alloy plate, a copper plate, an aluminum plate, or a plate selected from iron (a plate material different from the upper plate can be used).
The surface of the upper plate selected from a magnesium alloy plate, an aluminum alloy plate or a copper plate is subjected to friction welding with a hollow cylindrical tool or a stepped hollow cylindrical tool that rotates at a high speed, and a hollow cylindrical tool or a stepped hollow cylindrical tool is obtained. It penetrates into the plate. The plate inside the hollow cylindrical portion of the tool is melted and raised to the inside of the hollow cylindrical portion, and a hollow cylinder forming a top portion and a side portion is formed by the upper plate material.
When the tool reaches the bottom surface of the upper plate, the rotation is stopped and the bottom of the lower hollow plate is formed by friction welding on the deformed hollow cylinder. Thus, it is possible to obtain a projection having a novel shape in which the bottom of the plate is friction welded.
By pulling them away from the tool and cooling them, it is possible to complete a new-shaped protrusion having an independent shape.

An apparatus for forming a protrusion formed by two plates of the present invention is as follows.
A hollow cylindrical tool or a stepped hollow cylindrical tool is attached to the tip of the main shaft of the friction welding / moving means by a rotational drive that can rotate and move in the propulsion direction, and is stacked in two. The upper plate member is a plate selected from a magnesium alloy plate, an aluminum alloy plate or a copper plate, and the lower plate is a plate selected from a magnesium alloy plate, an aluminum alloy plate, a copper plate, an aluminum plate or an iron plate, and the upper plate Is in a state of friction welding with a hollow cylindrical tool rotating at a high speed or a stepped hollow cylindrical tool, allowing the tool to enter the upper plate, melting the plate inside the hollow cylindrical portion of the tool, and raising the plate And when the tool reaches the bottom surface of the upper plate, the rotation of the tool is stopped, and the formed hollow cylinder is subjected to friction welding. It forms the bottom by the side of the plate material, which due to be released from the tool, a forming device of the projecting portion by two plate.
FIG. 5 is an overall view of an apparatus for performing the friction welding process B with the hollow cylindrical tool or the stepped hollow cylindrical tool 3 of the present invention.
A column 7 is provided on the support base 8 of the friction stir processing apparatus so as to extend upward. The plate 4 is fixed to the upper surface of the support base 8 by clamping means (not shown).
The plate 4 is a plate in which the upper plate stacked in two is selected from a magnesium alloy plate, an aluminum alloy plate or a copper plate, and the lower plate is a magnesium alloy plate, an aluminum alloy plate, a copper plate, an aluminum plate or iron. (A material different from that of the upper plate can be used for the material of the plate).
The column 7 is provided with a friction welding / moving motor 1 that is a friction welding / moving means by a rotational drive that can rotate and move in the propulsion direction. A chuck 3 as an attaching means is provided at the tip of the main shaft 9.
A hollow cylindrical tool or stepped through a chuck 5 as an attachment means at the tip of the main shaft of the friction welding / moving motor 1 which becomes a friction welding / moving means by a rotational drive that can rotate and move in the propulsion direction. The hollow cylindrical tool 3 is attached, and the surface of the plate member 4 is friction-welded with the hollow cylindrical tool or the stepped hollow cylindrical tool to enter the plate, and the plate member inside the hollow cylindrical portion of the tool is melted. The plate inside the hollow cylindrical portion of the tool is in a state of rising in the hollow cylindrical portion in a molten state, forming a hollow column having a top portion and a side wall portion, and when the tool reaches the bottom surface, the tool is rotated. By stopping and cooling the hollow cylinder away from these tools, the material selected from the magnesium alloy plate, aluminum alloy plate and copper plate, which is the upper plate, is raised to form the side wall portion and the top portion, When the tool reaches the bottom surface of the upper plate, the rotation is stopped, and the bottom portion 10 is formed by the lower plate in the deformed hollow cylinder 6 by friction welding, and the lower column is formed in the hollow cylinder shape by the upper plate. Produces a protrusion with a novel shape by friction welding the bottom of the side plate.

The upper plate stacked in two sheets is a plate selected from a magnesium alloy plate, an aluminum alloy plate or a copper plate, and the lower plate is selected from a magnesium alloy plate, an aluminum alloy plate, a copper plate, an aluminum plate or iron A material different from the first sheet can be used. ).
The upper plate is selected to have a lower melting point and a higher coefficient of thermal expansion than the material constituting the hollow cylindrical tool or the stepped hollow cylindrical tool.
The thickness of the plate material can be determined as appropriate. In general, the upper plate may be a thin plate, and is usually 0.3 mm or more, and those having a range of about 2 mm are used. In the embodiment, the one of 1.4 mm is cited. Since the lower plate material forms the bottom, it is not particularly limited. There is no problem in cases where the thickness is equal to or less than that of the upper plate, or even if a dent or the like is generated on the back surface. If the same thickness is used, there will be no problem of dents.

If the plate material is used for the hollow cylindrical tool or the stepped hollow cylindrical tool 3, one made of SUS304 stainless steel can be used. What is necessary is just to determine according to the material to be used. These tools 3 can be used as long as they have a higher melting point and a smaller coefficient of thermal expansion than the plate material 4.
A hollow cylindrical tool and a stepped hollow cylindrical tool are shown in FIG.
The inner diameter of the hollow cylindrical tool can be appropriately determined according to the outer diameter of the protrusion to be formed. Specifically, those having many shapes such as an outer diameter of 15 mm, an inner diameter of 10 mm, an outer diameter of 8 mm, an inner diameter of 5 mm; an outer diameter of 6 mm, an inner diameter of 3 mm; an outer diameter of 6 mm, and an inner diameter of 3 mm can be appropriately selected and used. . The maximum outer diameter is about 20 mm and the inner diameter is about 15 mm. The minimum outer diameter is about 5 mm and the inner diameter is about 3 mm.
The end of the hollow cylindrical tool 3 can be used in various shapes (FIG. 2). The shape of the protrusion 6 formed in accordance with this shape also changes.
The processing (friction welding process) conditions are determined by the shape of the hollow cylindrical tool, the number of revolutions, the pressure applied to the plate material, and the processing time.

  The number of rotations of the hollow cylindrical tool 3 is the same as that described above, and may be operated in the same manner. The rotational speed may be 5000 rpm or more, and 8000 to 10,000 rpm is adopted. Of course, it may be 10,000 rpm or more, and is determined by the apparatus used. According to the experiments by the inventors, the speed of about 50000 rpm has been confirmed.

The friction pressure applied to the plate material by the hollow cylindrical tool or the stepped hollow cylindrical tool 3 is sufficient to be 15 MPa or more, and in the examples, the case of 30 MPa is cited. The upper limit is determined by the device used. There is no need to raise it unnecessarily.
The peripheral speed may be about 150 m / min.

  When a hollow cylindrical tool or a stepped hollow cylindrical tool is rubbed into the surface of the upper plate at a high speed, the plate material enters the hollow cylindrical part of the tool in a raised state, and the height rising into the hollow cylindrical part is Generally, it is about 5 mm to 7 mm (about 7 mm has been confirmed). The height of the hollow cylindrical part of the hollow cylindrical tool needs to be higher than this height. If the height is shorter than this, there will be no place to go out after the climax, and trouble will occur. The height of the resulting protrusion is lower than this height because the protrusion is cooled.

The shape of the protrusion is as shown in FIGS.
The outer shape of the protruding portion is the same shape as when a hollow cylindrical tool is copied, and the rubbing trace from the hollow rotating tool remains on the outer periphery of the protruding portion. On the outer periphery of the tip of the protrusion, bulging by the flash is recognized (a portion swelled in an annular shape is recognized along the outer side of the top). The inside of the projecting portion has a shape in which a plate material is taken in, and is a hollow cylinder, and the bottom is formed on the bottom plate on the bottom surface. Also, there is no recess at the bottom.
As shown in FIGS. 7 to 10, the outer diameter of the protrusion of the hollow cylinder is close to the inner diameter of the hollow cylindrical tool, and the height of the protrusion is close to 5 to 7 mm. The height of the outer shape of the protrusion is high with respect to the outer diameter of the protrusion, and the shape is abrupt (it is considered that such a shape cannot be formed by deep drawing or the like). A flat part is seen at the top.
By making a hole in the top, the screw can be unscrewed. Moreover, a screw thread can also be provided in the outer side of a projection part. It can be used to screw a housing or the like.
The resulting compressive strength of the protrusion can withstand screwing. It can be used in a wide range as a means for screwing the housing.
A macroscopic structure of the central cross section of the protrusion is shown in FIG. An example of the obtained height is as shown in FIG. The height is equal to or less than the inner height of the cylindrical tool, and differs depending on the cut surface of the hollow cylindrical tool used.
The compressive strength of the resulting protrusion varies depending on the shape of the end (FIG. 14). The staircase type (Step type (d)) shows the strongest strength.
The state of the fracture surface of the protrusion is as shown in FIG.
Specific examples are shown below as examples.

A commercially available aluminum alloy thin plate (plate thickness 1.4 mm) was machined to □ 30 mm, and then the processed surface was degreased and washed. The hollow cylindrical tool was made of cylindrical SUS304 stainless steel, and had a tool outer diameter of 15 mm and an inner diameter of 10 mm.
At the time of processing, the aluminum alloy thin plate was fixed with a jig. At the time of processing, the hollow cylindrical tool rotation speed was 9550 rpm and the friction pressure was 30 MPa from the results of preliminary experiments. The process was completed with the hollow cylindrical tool being pushed in by 1.4 mm, the same as the plate thickness. Appearance observation, structure observation, and tensile test of the obtained protrusion were performed at room temperature (threaded into the protrusion to obtain a test piece).
The external shape of the protrusion is as shown in FIG. The outside of the protruding portion was in a state as if a hollow cylindrical tool was copied, and the rubbing trace by the rotating tool remained on the outer periphery of the protruding portion. On the outer periphery of the tip of the protrusion, bulging due to flashing was observed (a part that swelled in an annular shape was recognized along the outer side of the top). It was observed that the inside of the protrusion was taken in and was a hollow cylinder and hollow at the bottom.
The hollow cylindrical protrusion has an outer diameter of approximately 10 mm and a protrusion height of approximately 7 mm.
The height of the outer shape of the protruding portion is high with respect to the outer diameter of the protruding portion, and the shape is steep (it is considered that such a shape cannot be formed by deep drawing or the like). A flat part is seen at the top.

A commercially available AZ31 magnesium alloy thin plate (plate thickness: 1.0 mm) was used as the plate. □ After machining to 30 mm, the machined surface was degreased and washed. The stepped hollow cylindrical tool was made of cylindrical SUS304 stainless steel, and was a hollow hollow cylindrical tool having an outer diameter of 8 mm and an inner diameter of 4 mm. From the results of preliminary experiments, the hollow cylindrical tool rotation speed was 9600 rpm and the friction pressure was 30 MPa. The process was completed with the hollow cylindrical tool being pushed in by 1.0 mm, which is the same as the plate thickness. Appearance observation, structure observation, and tensile test of the obtained protrusion were performed at room temperature (threaded into the protrusion to obtain a test piece).
The external shape of the protrusion is as shown in FIG. The outside of the protruding portion was in a state as if a hollow cylindrical tool was copied, and the rubbing trace by the rotating tool remained on the outer periphery of the protruding portion. On the outer periphery of the tip of the protrusion, bulging due to flashing was observed (a part that swelled in an annular shape was recognized along the outer side of the top). The inside of the protrusion is a hollow cylinder with the shape taken in. The inside of the hollow cylinder can be observed from the back side.
A hole was made in the center.
The outer diameter of the protrusion of the hollow cylinder is approximately 4 mm, and the height of the protrusion is close to 6 mm.
The height of the outer shape of the protruding portion is high with respect to the outer diameter of the protruding portion, and the shape is steep (it is considered that such a shape cannot be formed by deep drawing or the like). A flat part is seen at the top.

Commercially available AZ magnesium alloy thin plates (thickness 1.0 mm) were used as two upper and lower plates. □ After machining to 30 mm, the machined surface was degreased and washed. The stepped hollow cylindrical tool was made of cylindrical SUS304 stainless steel, and had a tool outer diameter of 8 mm and an inner diameter of 5 mm.
At the time of processing, the magnesium alloy thin plate was fixed with a jig. At the time of processing, the hollow cylindrical tool rotation speed was 10000 rpm and the friction pressure was 30 MPa from the results of preliminary experiments. The process was completed with the hollow cylindrical tool being pushed in by 1.0 mm, which is the same as the plate thickness. Appearance observation, structure observation, and tensile test of the obtained protrusion were performed at room temperature (threaded into the protrusion to obtain a test piece).
The external shape of the protrusion is as shown in FIG. The outside of the protruding portion was in a state as if a hollow cylindrical tool was copied, and the rubbing trace by the rotating tool remained on the outer periphery of the protruding portion. On the outer periphery of the tip of the protrusion, bulging due to flashing was observed (a part that swelled in an annular shape was recognized along the outer side of the top). The inside of the protrusion was a hollow cylinder, and the bottom due to the lower plate was observed.
The hollow cylindrical protrusion has an outer diameter close to 5 mm and a protrusion height close to 7 mm.
The height of the outer shape of the protruding portion is high with respect to the outer diameter of the protruding portion, and the shape is steep (it is considered that such a shape cannot be formed by deep drawing or the like). A flat part is seen at the top.
A slight trace was observed on the back side.

A commercially available AZ31 magnesium alloy thin plate (plate thickness: 1.0 mm) was used as two upper and lower plates. □ After machining to 30 mm, the machined surface was degreased and washed. The hollow cylindrical tool was made of cylindrical SUS304 stainless steel, and the tool had an outer diameter of 8 mm and an inner diameter of 5 mm.
At the time of processing, the magnesium alloy thin plate was fixed with a jig. At the time of processing, the hollow cylindrical tool rotation speed was 10000 rpm and the friction pressure was 30 MPa from the results of preliminary experiments. The process was completed with the hollow cylindrical tool being pushed in by 1.0 mm, which is the same as the plate thickness. Appearance observation, structure observation, and tensile test of the obtained protrusion were performed at room temperature (threaded into the protrusion to obtain a test piece).
The external shape of the protrusion is as shown in FIG. The outside of the protruding portion was in a state as if a hollow cylindrical tool was copied, and the rubbing trace by the rotating tool remained on the outer periphery of the protruding portion. On the outer periphery of the tip of the protrusion, bulging due to flashing was observed (a part that swelled in an annular shape was recognized along the outer side of the top). It was observed that the inside of the protruding part was a hollow cylinder with the shape taken in, and the bottom part by the lower plate was formed by friction welding.
The hollow cylindrical protrusion has an outer diameter close to 5 mm and a protrusion height close to 7 mm.
The height of the outer shape of the protruding portion is high with respect to the outer diameter of the protruding portion, and the shape is steep (it is considered that such a shape cannot be formed by deep drawing or the like). There is a flat part at the top

A commercially available AZ31 magnesium alloy thin plate (plate thickness: 1.0 mm) was used as two upper and lower plates. □ After machining to 30 mm, the machined surface was degreased and washed. The stepped hollow cylindrical tool is made of cylindrical SUS304 stainless steel, and has a tool outer diameter of 8 mm and an inner diameter of 3 mm.
At the time of processing, the magnesium alloy thin plate was fixed with a jig. In processing, the hollow cylindrical tool rotation speed was 9600 rpm and the friction pressure was 30 MPa from the results of preliminary experiments. The process was completed with the hollow cylindrical tool being pushed in by 1.0 mm, the same as the upper plate thickness. Appearance observation, structure observation, and tensile test of the obtained protrusion were performed at room temperature (threaded into the protrusion to obtain a test piece).
The appearance of the protrusion is as shown in FIG. The outside of the protruding portion was in a state as if a hollow cylindrical tool was copied, and the rubbing trace by the rotating tool remained on the outer periphery of the protruding portion. On the outer periphery of the tip of the protrusion, bulging due to flashing was observed (a part that swelled in an annular shape was recognized along the outer side of the top). It was observed that the inside of the protrusion was taken in and was a hollow cylinder, and the bottom of the lower plate was formed by friction welding. Traces are observed on the back side.
The outer diameter of the protrusion of the hollow cylinder is close to about 5 mm, and the height of the protrusion is close to 6 mm.
The height of the outer shape of the protruding portion is high with respect to the outer diameter of the protruding portion, and the shape is steep (it is considered that such a shape cannot be formed by deep drawing or the like). A flat part is seen at the top.

A commercially available AZ31 magnesium alloy thin plate (plate thickness: 1.0 mm) was used as two upper and lower plates. □ After machining to 30 mm, the machined surface was degreased and washed. The stepped hollow cylindrical tool was made of cylindrical SUS304 stainless steel, and had a tool outer diameter of 8 mm and an inner diameter of 5 mm.
At the time of processing, the magnesium alloy thin plate was fixed with a jig. In processing, the hollow cylindrical tool rotation speed was 9600 rpm and the friction pressure was 30 MPa from the results of preliminary experiments. The process was completed with the hollow cylindrical tool being pushed in by 1.0 mm, the same as the upper plate thickness. Appearance observation, structure observation, and tensile test of the obtained protrusion were performed at room temperature (threaded into the protrusion to obtain a test piece).
The external shape of the protrusion is as shown in FIG. The outside of the protruding portion was in a state as if a hollow cylindrical tool was copied, and the rubbing trace by the rotating tool remained on the outer periphery of the protruding portion. On the outer periphery of the tip of the protrusion, bulging due to flashing was observed (a part that swelled in an annular shape was recognized along the outer side of the top). It was observed that the inside of the protrusion was taken in and was a hollow cylinder, and the bottom of the lower plate was formed by friction welding. Traces are observed on the back side.
The outer diameter of the protrusion of the hollow cylinder is close to about 5 mm, and the height of the protrusion is close to 6 mm.
The height of the outer shape of the protruding portion is high with respect to the outer diameter of the protruding portion, and the shape is steep (it is considered that such a shape cannot be formed by deep drawing or the like). A flat part is seen at the top.

A commercially available AZ31 magnesium alloy thin plate (plate thickness 1.0 mm, σ _B = 13.6%, 50.3 HK 0.05) was machined to □ 30 mm, and then the processed surface was degreased and washed. The tool was made of cylindrical SUS304 stainless steel, and the machined one shown in FIG. 2 was used. The inner diameter of the tool was set to 6 mm on the assumption that an M4 screw was machined inside the generated protrusion.
At the time of processing, the upper plate and the lower plate were fixed with a jig so that a margin of overlap was 25 mm. In the processing, the hollow cylindrical tool was rotated at 9550 rpm and the friction pressure was 30 MPa from the results of the preliminary experiment, and the hollow cylindrical tool was finished in a state where it was pushed in by 1.4 mm, which is the same as the plate thickness of the upper plate. Appearance observation, structure observation, and tensile test of the obtained protrusion (M4 screw processing was performed in the protrusion to obtain a test piece) were performed at room temperature.

The test results were as follows.
The appearance of the protrusion is as shown in FIG. The shape of the protrusion is as if a hollow cylindrical tool was copied, and scratch marks from the rotating tool remain on the outer periphery of the protrusion. Swelling due to flash was observed on the outer periphery of the tip of the protrusion. In Taper, the flash was in a state of covering the tip of the protrusion. In Straight, a spiral pattern was observed on the side surface of the protrusion.
Although no discoloration or deformation due to heat effects was observed on the back surface of the lower plate in Taper and Champfering, slight discoloration was observed in Straight and Step. Although not shown in the drawing, the separated upper plate was punched by a hollow cylindrical tool, and a slight flash was observed around the punched hole.
In FIG. 12, which shows a macroscopic structure of the cross section of the central portion of the protrusion, it is shown that the protrusion is hollow (cavity) regardless of the difference in the shape of the end of the hollow cylindrical tool. The thickness of the protrusion was about the same as that of the base material (plate material) at the top of the protrusion, but on the side of the protrusion, the thickness gradually decreased from the top of the protrusion to the bottom. In Straight, the cavity was larger than the shape of other hollow cylindrical tools, and the thickness of the bottom of the protrusion was clearly reduced. Nugget formation observed in stud welding was not observed at the joint interface between the bottom of the protrusion and the lower plate. Further, no deformation of the lower plate was observed regardless of the shape of the hollow cylindrical tool.

The height from the bottom to the top at the center of the protrusion was defined as the protrusion height, and the measurement results are shown in FIG. The theoretical value shown in the figure is a value calculated on the assumption that the protrusion has the same thickness as the base material and is molded in an ideal state without loss due to flash or the like. The height of the protrusion was highest at Straight, followed by Step and Chamfering, the Taper was the lowest, and the difference from the theoretical value was also large. This is considered to be due to the occurrence of flash in a state that covers the tip of the protrusion in Taper, as is apparent from external observation. In Straight, as observed in the macroscopic structure, the thickness of the bottom of the protrusion became thinner, so that the height of the protrusion became larger than the theoretical value.

According to the result of the tensile test (FIG. 14), the tensile load of the protrusion is high in Step and Champfering, shows a value of about 650 N, and then is Taper, and the Straight where the thin part exists at the bottom of the protrusion is low. became.
According to the result (FIG. 15) showing the state of the cross section after the tensile test of the protrusion, the fracture position was broken from the bottom of the protrusion at the highest strength of Champing and Step, but the taper was joined to the upper and lower plates. It peeled from the part. In Straight, it broke from the thin part.

Overall view of the apparatus for friction welding with the hollow cylindrical tool of the present invention (when using a single plate) Diagram showing various shapes of the end of a hollow cylindrical tool Diagram showing hollow cylindrical tool and stepped hollow cylindrical tool The figure which shows the hollow cylinder which formed the aluminum alloy thin plate using the hollow cylindrical tool of 15 mm outside diameter made from SUS304 stainless steel and 10 mm inside diameter Overall view of the apparatus for friction welding with the hollow cylindrical tool of the present invention (when using two plates) The figure which shows the hollow cylinder which formed the AZ31 magnesium alloy thin plate using the hollow cylindrical tool made from SUS304 stainless steel with an outer diameter of 8 mm and an inner diameter of 4 mm. The figure which shows the hollow cylinder which has the bottom part which formed the AZ31 magnesium alloy thin plate using the hollow cylindrical tool made from SUS304 stainless steel with an outer diameter of 8 mm and an inner diameter of 5 mm. The figure which shows the hollow cylinder which has the bottom part which formed the AZ31 magnesium alloy thin plate using the hollow cylindrical tool made from SUS304 stainless steel with an outer diameter of 8 mm and an inner diameter of 5 mm. The figure which shows the hollow cylinder which has a bottom part which formed the AZ31 magnesium alloy thin plate using the hollow cylindrical tool made from SUS304 stainless steel with an outer diameter of 6 mm and an inner diameter of 3 mm. The figure which shows the hollow cylinder which has the bottom part which formed the AZ31 magnesium alloy thin plate using the stepped hollow cylindrical tool made from SUS304 stainless steel outer diameter 8mm and inner diameter 5mm. The figure which shows that a projection part changes according to the various shapes of the edge part of a hollow cylindrical tool. The figure which shows the macroscopic organization of the projection central part cross section The figure which shows the result of having measured the height from the bottom of the projection center to the top The figure which shows that the compressive strength of a projection part changes according to the shape of an end. The figure which shows the state of the protrusion fracture surface

Explanation of symbols

A: Friction welding equipment
B: Friction welding processing device 1: Friction welding / moving motor 2: Friction welding / moving motor support part 3: Hollow cylindrical tool or stepped hollow cylindrical tool 4: Plate material 5: Chuck 6: Protruding part 7: Column 8: Support base 9: Spindle 10: Bottom

Claims (3)

  The upper plate material stacked in two is a plate material selected from magnesium alloy plate, aluminum alloy plate or copper plate, and the lower plate material is selected from magnesium alloy plate, aluminum alloy plate, copper plate, aluminum plate or iron Formed of two plates, wherein a hollow cylinder having a top portion and a side wall portion is formed in a raised state after the upper plate member is melted, and the bottom portion is formed by the lower plate member Protruding part.   The upper plate material stacked in two is a plate material selected from magnesium alloy plate, aluminum alloy plate or copper plate, and the lower plate material is selected from magnesium alloy plate, aluminum alloy plate, copper plate, aluminum plate or iron The upper plate is friction-welded with a hollow cylindrical tool or a stepped hollow cylindrical tool that rotates at a high speed, and the upper plate in the hollow cylindrical portion of the tool is melted while the tool enters the plate. When the tool reaches the bottom surface of the upper plate, the rotation of the tool is stopped to form a hollow cylinder having a top portion and a side wall portion, and friction welding is performed on the lower side. A protrusion formed by two plates, wherein the protrusion is formed by forming a bottom portion by a plate, and separating these from the tool and cooling them. The method of formation. The shape of the end of the hollow cylindrical tool or stepped hollow cylindrical tool is straight type (Stright type (a)), inclined type (Taper type (b)), annular steeply inclined type (Chamfering type (c)). Or a step type (Step type (d)). 3. A method of forming a projection formed by two plate members.

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