JP2010076762A - Frame of welded structure with closed section - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a frame of a welded structure with closed section which does not largely open or break at a welded portion of the frame when an external force is added to crush the frame at the time of collision or the like. <P>SOLUTION: In the frame of the welded structure having a closed section structure, opening end edges of two frame members 1a, 1c made of aluminum alloy having opening sections are welded with each other, whereby an internal reinforcing material 5 is provided in the interior. The internal reinforcing material 5 is composed of a plate material 5b and a reinforcing member 5a inserted in a plurality of incisions formed on the plate material 5b. The reinforcing member 5a is contacted with the frame members 1a, 1c at the edge part in the orthogonal direction to a welding line. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a welded structure closed section frame such as a vehicle body frame and a suspension frame of an automobile, and more particularly to a welded structure closed section frame in which an external force is applied to the frame during a collision or the like and the absorbed energy does not decrease.

  In order to ensure the safety of passengers, the vertical direction of the frame (axial direction) of the vehicle body such as a car frame, particularly a side frame (side member), a crash box, a bumper stay, a suspension frame, etc. A hollow strength member that is crushed and bears impact energy is provided. Recently, from the viewpoint of reducing the weight of the vehicle body, an energy absorbing member formed of an extruded shape made of an aluminum alloy has been proposed as a hollow strength member (for example, Patent Document 1).

  However, an energy absorbing member using a hollow extruded shape is suitable for an energy absorbing member having a linear axial direction such as a bumper stay, but for example, a front side frame (side member) of a passenger car is bent in the axial direction. However, there is a problem that a linear extruded shape must be formed by bending, which requires high processing accuracy and high processing cost. In addition, the cross-sectional shape of the extruded shape member is constant, and it is difficult to change the cross-sectional shape depending on the required part of the member and the attachment part, and there is a problem that the design of the frame is limited.

  For this reason, energy absorbing members in which closed cross-section members formed by pressing plate members are joined by spot welding, arc welding, laser welding, or the like to form closed cross-sections have also been proposed (for example, Patent Document 2, Patent Document 3 and Patent Document 4).

  Furthermore, in the energy absorbing member, from the viewpoint of improving its performance, a method for improving energy absorbing performance by providing a weak portion such as a notch (for example, Patent Document 5), and a reinforcing member having a weak portion provide energy absorbing performance. An improvement method (for example, Patent Document 6) has also been proposed.

Japanese Patent Laid-Open No. 2004-203202 JP 7-310156 A JP-A-11-208504 JP 2003-175858 A Japanese Patent Laid-Open No. 3-65634 Japanese Patent Laid-Open No. 11-342862

  However, the structure disclosed in the above-described prior art has a greater degree of freedom in cross-sectional design than a frame made of an extruded profile. However, when an energy absorbing member having the above-described structure is formed of an aluminum alloy, the stress is reduced. Since the welded portion that tends to concentrate is weaker than the base material portion (non-welded portion), there is a problem that the welded portion opens greatly when an external force is applied to the frame during a collision or the like to cause collapse. If the welded part opens and breaks, the absorbed energy at the time of crushing may decrease, and since the opening becomes a sharp fracture surface, exposure of this fracture surface may damage the passenger and the surrounding environment. There is a problem.

  The present invention has been made in view of such problems, and provides a welded structure closed cross-section frame that does not greatly open or break at the welded portion of the frame when an external force is applied and crushes during a collision or the like. For the purpose.

  A welded structure closed section frame according to the present invention is a welded structure closed section frame in which two aluminum alloy frame members having an open section are closed by welding their open end edges to each other. An internal reinforcing material is arranged, and the internal reinforcing material is a plate material arranged in the longitudinal direction of the frame member inside, and the plate material is cut at a predetermined interval, and the surface of the cut is a surface of the plate material. And a plurality of reinforcing members that are inserted and arranged so as to be perpendicular to each other, wherein the reinforcing members are in contact with opposite side surfaces where welded portions of the frame members are present. .

  For example, the two aluminum alloy frame members are joined by butt joint welding, or the two aluminum alloy frame members are joined by lap joint welding.

  According to the present invention, when an external force is applied to the closed cross-section frame that constitutes a closed cross section by welding two aluminum alloy frame members having an open cross section, such as at the time of a collision, and collapses, Since the two welded frame members do not greatly open at the welded portion, there is no decrease in absorbed energy at the time of crushing, and there is no possibility of damaging the occupant and the surrounding environment due to exposure of the sharp opening fracture surface.

It is a typical perspective view which shows the welding structure closed cross-section frame which concerns on the 1st reference example of this invention. It is a typical perspective view which shows the welding structure closed cross-section frame which concerns on the 2nd reference example of this invention. (A) is a typical side view which shows the welded structure closed cross-section frame which concerns on the 3rd reference example of this invention, (b) is the sectional view on the AA line in (a). (A) is a typical side view which shows the welded structure closed cross-section frame which concerns on the 3rd reference example of this invention, (b) is the sectional view on the AA line in (a). (A) is a typical side view which shows the welding structure closed cross-section frame which concerns on the 4th reference example of this invention, (b) is the sectional view on the AA line in (a). (A) is a typical side view which shows the welding structure closed cross-section frame which concerns on the 5th reference example of this invention, (b) is the sectional view on the AA line in (a). (A) is a typical side view which shows the welding structure closed cross-section frame which concerns on embodiment of this invention, (b) is the sectional view on the AA line in (a). It is a typical perspective view which similarly shows the shape of the internal reinforcement material 5 of embodiment of this invention. (A) is a typical side view which shows the welding structure closed cross-section frame which concerns on the 6th reference example of this invention, (b) is the sectional view on the AA line in (a). 6 is a schematic perspective view showing a welded structure closed section frame of Comparative Example 1. FIG. 6 is a schematic perspective view showing a welded structure closed cross-section frame of Comparative Example 2. FIG. 6 is a schematic perspective view showing a fracture situation of a welded structure closed cross-section frame of Comparative Example 2. FIG. (A) is the sectional view on the AA line in FIG. 12, (b) is the sectional view on the BB line similarly. It is a typical perspective view which shows the destruction condition of the welded structure closed cross-section frame of Reference Test Example 2. It is the sectional view on the AA line in FIG. (A) is a schematic top view which shows the destruction condition of the welded structure closed cross-section frame of Reference Test Example 6, and (b) is also a schematic left side view.

  Hereinafter, embodiments of the present invention will be specifically described with reference to the accompanying drawings. First, a first reference example of the present invention will be described. FIG. 1 is a schematic perspective view showing a welded structure closed section frame according to a first reference example of the present invention. An aluminum alloy sheet is formed by press working or the like to form a U-shaped frame member 1a having an open cross section. An internal reinforcing member 2 having a rectangular shape is connected to the inner surface of the frame member 1a at equal intervals, and the open end of the frame member 1b having the same shape as the frame member 1a is opposed to the frame member 1a. The edges are connected to each other by MIG (Metal Inert Gas) welding or the like, thereby forming a welded structure closed section frame having a closed section in the shape of a mouth provided with the internal reinforcing material 2. In the present embodiment, the welded portion of the frame is a butt joint.

  Next, the operation of the welded structure closed section frame of this reference example configured as described above will be described. When an external force is applied in the longitudinal direction of the welded structure closed section frame, such as during a vehicle collision, the welded structure closed section frame is deformed. Thereby, the energy by external force is absorbed. At this time, the internal reinforcing member 2 has a higher compressive strength in the direction connecting the opposed surfaces where the welded portions of the frame member are present than the compressive strength in any direction perpendicular to this direction. Therefore, the welded portion does not open.

  Next, a second reference example of the present invention will be described. FIG. 2 is a schematic perspective view showing a welded structure closed section frame according to the present reference example. 2, the same components as those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted. An aluminum alloy sheet is formed by press working or the like to form a U-shaped frame member 1a having an open cross section. An inner reinforcement member 2 having a rectangular shape is connected to the inner surface of the frame member 1a at equal intervals, and a frame member 1c having an inner surface interval equal to the outer surface interval of the frame member 1a is connected to the frame member 1a. In a state of facing each other, the open end edges are partially overlapped and connected by MIG welding or the like, that is, overlapped fillet welded, whereby the welded structure closed cross-section frame provided with the internal reinforcement 2 is formed. Is formed. In the present embodiment, the welded portion of the frame is a lap joint.

  Next, the operation of the welded structure closed section frame of this reference example configured as described above will be described. Similar to the operation of the welded structure closed section frame according to the first reference example described above, when an external force is applied in the longitudinal direction of the welded structure closed section frame during a vehicle collision or the like, the welded structure closed section frame is deformed. Thereby, the energy by external force is absorbed. At this time, the welded portion does not open due to the same effect as in the first embodiment.

  Next, a third reference example of the present invention will be described. 3 (a) and 4 (a) are schematic side views showing a welded structure closed section frame according to this reference example, and FIGS. 3 (b) and 4 (b) are FIGS. 3 (a) and 4 (b). It is an AA line sectional view in a). 3 and 4, the same components as those in FIGS. 1 and 2 are denoted by the same reference numerals, and detailed description thereof is omitted.

  An aluminum alloy sheet is formed by press working or the like to form a U-shaped frame member 1a having an open cross section. The inner reinforcing material 3 is connected to the inner surface of the frame member 1a at regular intervals. The internal reinforcing member 3 is formed longer than the U-shaped opposing sides of the frame member 1a, and the portions not contacting the two opposing sides of the frame member 1a are inclined inward, thereby An inclined part is provided in the part. Further, the difference between the length of the internal reinforcing member 3 and the length from the inner bottom surface of the frame member 1a to the front end of the frame member 1a is designed to be equal to the length from the front end of the frame member 1a to the inner bottom surface of the frame member 1c. ing.

  In the present reference example, as shown in FIG. 4B, the internal reinforcing member 3 and the frame member 1a are connected only on the side surface of the U-shaped frame. The frame member 1c having an inner surface interval equal to the outer surface interval of the frame member 1a is opposed to the frame member 1a, and a part of the frame member 1c has an overlap determined by the height of the internal reinforcing member 3 or the like. Are connected, that is, overlapped fillet welds are formed, thereby forming a welded structure closed section frame provided with an internal reinforcement 3.

  When welding with a lap joint, it is difficult to position the frame member 1a and the frame member 1c so as to have a desired lap joint length, but in this reference example, the internal reinforcing material 3 is the bottom surface of both frame members. It is in a shape to abut. Thereby, the internal reinforcing material 3 has not only the function of reinforcing the welded structure closed section frame but also the function of positioning the frame welded portion.

  Next, the operation of the welded structure closed section frame of this reference example configured as described above will be described. Similar to the operation of the welded structure closed section frame according to the first and second reference examples described above, when an external force is applied in the longitudinal direction of the welded structure closed section frame, such as during a vehicle collision, the welded structure closed section frame is deformed. To do. At this time, unlike the first and second reference examples, since the internal reinforcing material 3 is in contact with both the frame members 1a and 1c, the absorbed energy becomes higher when absorbing the energy due to the external force. Further, at this time, the internal reinforcing member 3 is provided with inclined portions at the corners, and the compressive strength in the direction connecting the opposed surfaces where the welded portions of the frame members are present is compressed in any direction perpendicular to this direction. Since the strength is higher than the strength, the welded portion is not deformed so as to be recessed inward, and thus the welded portion does not open.

  Next, a fourth reference example of the present invention will be described. FIG. 5A is a schematic side view showing a welded structure closed section frame according to this reference example, and FIG. 5B is a sectional view taken along line AA in FIG. 5, the same components as those in FIGS. 1 to 4 are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the third reference example described above, the internal reinforcing member 3 and the frame member 1a are connected only on the side surface of the U-shaped frame as shown in FIG. As shown in FIG. 5, the internal reinforcing member 3 and the frame member 1a are connected only at the bottom surface of the U-shaped frame, and the other structure is the same as that of the third reference example. In addition to the operation of the third reference example and the effects obtained, the welded structure closed cross-section frame according to this reference example is connected only at the bottom surface and not connected at the side surface. The absorption form which deforms into the shape is promoted, and as a result, the opening fracture of the welded portion does not occur.

  Next, a fifth reference example of the present invention will be described. FIG. 6A is a schematic side view showing a welded structure closed section frame according to this reference example, and FIG. 6B is a sectional view taken along line AA in FIG. 6, the same components as those in FIGS. 1 to 5 are denoted by the same reference numerals, and detailed description thereof is omitted.

  An aluminum alloy sheet is formed by press working or the like to form a U-shaped frame member 1a having an open cross section. In addition, an internal reinforcing member 4 having a rectangular shape is connected to the inner surface of the frame member 1c having an inner surface interval equal to the interval between the outer surfaces of the frame member 1a. The frame member 1a and the frame member 1c are connected to each other. Are opposed to the distal end portion of the internal reinforcing member 4. Thereby, the internal reinforcing material 4 has not only the function of reinforcing the welded structure closed section frame but also the function of positioning the frame welded portion. The frame member 1 a and the frame member 1 c are opposed to each other, and a part thereof is connected by MIG welding or the like with an overlap determined by the height of the internal reinforcement member 4, that is, overlapped fillet welded. A closed cross-section frame with a welded structure is formed. The operation of this reference example and the effects obtained are the same as those of the second reference example described above.

  Next, an embodiment of the present invention will be described. Fig.7 (a) is a typical side view which shows the welding structure closed cross-section frame which concerns on this embodiment, FIG.7 (b) is the sectional view on the AA line in Fig.7 (a). 7, the same components as those in FIGS. 1 to 6 are denoted by the same reference numerals, and detailed description thereof is omitted.

  FIG. 8 is a schematic perspective view showing the shape of the internal reinforcing member 5 of the present embodiment. 8, the same components as those in FIGS. 1 to 7 are denoted by the same reference numerals, and detailed description thereof is omitted. The plate member 5b having the same dimension as the length in the longitudinal direction of the frame member 1c is provided with cuts at equal intervals by cutting or the like, and the internal reinforcing member 5a is inserted into the cuts in a direction perpendicular to the weld line, thereby causing the internal reinforcing material. 5 is formed. Since the internal reinforcement member 5 is in contact with the bottom surfaces of both frame members, the internal reinforcement member 5 has not only a function of reinforcing the closed cross-section frame of the welded structure but also a function of positioning the frame welded portion. Yes. Further, since the internal reinforcement 5 is self-supporting, the internal reinforcement 5 and the frame members 1a and 1c are not particularly welded, and the frame member 1a is inserted in the frame member 1c. The frame members 1a and 1c are connected to each other by MIG welding or the like with a part of the overlap determined by the height of the internal reinforcement member 5, that is, overlapped fillet welding is performed. A provided closed cross-section frame is formed.

  Next, the operation of the welded structure closed section frame of the present embodiment configured as described above will be described. Similar to the operation of the welded structure closed section frame according to the first to fifth reference examples described above, when an external force is applied in the longitudinal direction of the welded structure closed section frame during a vehicle collision or the like, the welded structure closed section frame is deformed. . At this time, unlike the first and second reference examples, since the internal reinforcing material 5 is in contact with both the frame members 1a and 1c, the absorbed energy becomes higher when absorbing the energy due to the external force. At this time, since the inner reinforcing member 5 is provided with a cut in a direction perpendicular to the direction connecting the opposed surfaces where the welded portions of the frame member are present, the compressive strength in the direction in which the cut is provided. Therefore, the compressive strength in the direction connecting the opposite surfaces where the weld is present is relatively high, so that the weld does not deform so as to be recessed inward, and thus the weld is opened. There is no.

  The internal reinforcing members 2 to 4 in the first to fifth reference examples described above and the plate member 5b in the embodiment of the present invention are provided at equal intervals in the longitudinal direction of the welded structure closed section frame. It does not need to be provided at intervals, and can be provided at appropriate intervals in consideration of the structure inside and outside the welded structure closed section frame.

  Next, a sixth reference example of the present invention will be described. Fig.9 (a) is a typical side view which shows the welded structure closed cross-section frame which concerns on this reference example, FIG.9 (b) is the sectional view on the AA line in Fig.9 (a). 9, the same components as those in FIGS. 1 to 8 are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the internal reinforcing material 6 of this reference example, the mouth-shaped extruded shape whose one side is shorter than the length of the inner side surface of the bottom side of the frame member 1a is cut to a length shorter than the length in the longitudinal direction of the frame member 1a. It is formed by being connected by welding or the like in a state in which a plurality are arranged horizontally. The mouth-shaped extruded shape member is arranged in the frame so that the direction of extrusion coincides with the direction connecting the surfaces where the welds exist. Since the internal reinforcing member 6 is simply formed by cutting an extruded profile and connected by welding or the like, the internal reinforcing member 6 is formed by cutting as in the internal reinforcing member 5 of the above-described embodiment of the present invention. Compared to, the processing cost is very low. Moreover, the connection between the cut-out extrusion-molded members may be a temporary attachment, and a large bonding strength is not required.

  The frame member 1c is opposed to the frame member 1a with the internal reinforcement member 6 inserted therein, and MIG welding is performed with the frame members 1a and 1c partially overlapping each other depending on the height of the internal reinforcement member 6. Etc., that is, a fillet welded by overlapped fillet, and thereby a welded structure closed section frame provided with an internal reinforcement 6 is formed.

  Next, the operation of the welded structure closed section frame of the sixth reference example configured as described above will be described. Similar to the operation of the welded structure closed section frame according to the first to fifth reference examples and the embodiment of the present invention, when an external force is applied in the longitudinal direction of the welded structure closed section frame, such as during a vehicle collision, the welded structure The closed section frame is deformed. At this time, unlike the first and second reference examples, since the internal reinforcing material 6 is in contact with both the frame members 1a and 1c, the absorbed energy becomes higher when absorbing the energy due to the external force. Further, at this time, since the extrusion-type extruded shape member is arranged in the frame so that the extrusion direction coincides with the direction connecting the surfaces where the welded portion exists, the internal reinforcing material 6 has the welded portion of the frame member. The compressive strength in the direction connecting the opposed surfaces is higher than the compressive strength in any direction perpendicular to this direction. Accordingly, the welded portion is not deformed so as to be recessed inward, and thus the welded portion is not opened.

  In addition, although the internal reinforcing material 6 in the above-mentioned 6th reference example uses the shape material of the same cross-sectional shape cut | disconnected from the same extrusion shape material, it is not necessarily required to use the shape material of the same shape, and welding structure In consideration of the internal structure of the closed cross-section frame, a plurality of types of profiles can be used.

  Examples for demonstrating the effects of the present invention will be described below. As Reference Test Example 1 of the present invention, a welded structure closed section frame according to the first reference example shown in FIG. 1 was prepared. The frame members 1a and 1b were formed by press working so as to have an open cross section using an A5454P-O aluminum alloy plate material having a plate thickness of 4 mm. The length of the frame members 1a and 1b in the longitudinal direction is 500 mm, and the length of the base is 100 mm on the outer surface.

  As the internal reinforcing material 2, an A5454P-O aluminum alloy plate material having a thickness of 4 mm is formed into a rectangular shape, and is placed at an equal interval of 100 mm in contact with the inner surface from a portion of 50 mm from the end of the frame member 1a. Connected by welding.

  Thereafter, MIG welding was performed with the frame members 1a and 1b facing each other so that the frame welded portion became a butt joint, thereby creating a welded structure closed section frame having a height of 100 mm. Further, MIG welding was performed by a normal MIG welding machine using an A4043WY welding wire having a wire diameter of 1.2 mm.

  As a result, a closed cross-section frame having a height of 100 mm, a width of 100 mm, and a length of 500 mm, having five internal reinforcing members 2 arranged at an interval of 100 mm inside the frame member 1a and having a butt joint was created.

  Further, as Comparative Example 1, as shown in FIG. 10, in Reference Test Example 1 described above, the inner reinforcing material 2 is not disposed on the inner surface of the frame member 1a, that is, a closed cross section of 100 mm × 100 mm and a 500 mm A welded structure closed section frame having a length and having a butt joint was prepared. 10, the same components as those in FIGS. 1 to 9 are denoted by the same reference numerals, and detailed description thereof is omitted.

  Further, as Reference Test Example 2 of the present invention, a welded structure closed section frame according to the second reference example shown in FIG. 2 was prepared. The frame members 1a and 1c were formed by pressing so as to have an open cross section using an A5454P-O aluminum alloy plate material having a plate thickness of 4 mm. The length of the frame members 1a and 1b in the longitudinal direction is 500 mm, the length of the bottom side of the frame member 1a is 100 mm on the outer side, and the length of the bottom side of the frame member 1c is 108 mm on the outer side.

  As the internal reinforcing material 2, an A5454P-O aluminum alloy plate material having a thickness of 4 mm is formed into a rectangular shape, and is placed at an equal interval of 100 mm in contact with the inner surface from a portion of 50 mm from the end of the frame member 1a. Connected by welding.

  After that, with the frame members 1a and 1c partially overlapping, MIG welding is performed so that the frame welding part becomes a lap joint, that is, overlapped fillet welding is performed, whereby a welded structure having a height of 100 mm. A closed section frame was created. Further, MIG welding was performed by a normal MIG welding machine using an A4043WY welding wire having a wire diameter of 1.2 mm.

  As a result, a welded structure having a height joint of 100 mm, a larger width of 108 mm, a smaller width of 100 mm, a length of 500 mm, five internal reinforcing members 2 arranged at intervals of 100 mm inside the frame member 1a, and having a lap joint. A closed section frame was created.

  Further, as Comparative Example 2, as shown in FIG. 11, a welded structure cross-section frame in which the internal reinforcing material 2 is not disposed on the inner surface of the frame member 1a in the above-described Reference Test Example 2 was created. 11, the same components as those in FIGS. 1 to 10 are denoted by the same reference numerals, and detailed description thereof is omitted.

  Further, as Reference Test Example 3 of the present invention, a welded structure closed cross-section frame according to the above-described third reference example shown in FIG. 4 was prepared. As the frame members 1a and 1c and the internal reinforcement member 3, an A5454P-O aluminum alloy plate material having a plate thickness of 4 mm was used as in Reference Test Examples 1 and 2. As shown in FIG.4 (b), the internal reinforcement material 3 and the frame member 1a were connected by MIG welding only in the side surface of the U-shaped frame. Then, the frame member 1a and the frame member 1c are connected by MIG welding in a state where an overlap is determined in part by the height of the internal reinforcing material 3, that is, overlapped fillet welding is performed, whereby the height is 100 mm. A closed cross-section frame was created. Further, MIG welding was performed by a normal MIG welding machine using an A4043WY welding wire having a wire diameter of 1.2 mm.

  Further, as Reference Test Example 4 of the present invention, a welded structure closed section frame according to the above-mentioned fourth reference example shown in FIG. 5 was prepared. In the closed cross-section frame of the reference test example 3, as shown in FIG. 4, the internal reinforcing member 3 and the frame member 1a are welded only on the side surface of the U-shaped frame, whereas the reference test example 4 As shown in FIG. 5, the inner reinforcing member 3 and the frame member 1a are different from each other in that they are welded only at the bottom surface of the U-shaped frame. .

  Further, as Reference Test Example 5 of the present invention, a welded structure closed section frame according to the above-mentioned fifth reference example shown in FIG. 6 was prepared. As the frame members 1a and 1c and the internal reinforcement member 4, an A5454P-O aluminum alloy plate material having a plate thickness of 4 mm was used as in Reference Test Examples 1 to 4. As shown in FIG.6 (b), the internal reinforcement material 4 which contact | abuts to the inner surface of the frame member 1c, and has a rectangular shape at equal intervals was arrange | positioned, and it connected by MIG welding. Then, the frame member 1a and the frame member 1c are connected by MIG welding in a state where an overlap is partially determined by the height of the internal reinforcing member 4, that is, overlapped fillet welding is performed, whereby the height is 100 mm. A closed cross-section frame was created. Further, MIG welding was performed by a normal MIG welding machine using an A4043WY welding wire having a wire diameter of 1.2 mm.

  Further, as an example of the present invention, a welded structure closed section frame according to the above-described embodiment of the present invention shown in FIG. 7 was created. As the frame members 1a and 1c and the internal reinforcing material 5, the A5454P-O aluminum alloy plate material having a plate thickness of 4 mm was used as in Reference Test Examples 1 to 5. The plate member 5b having the same dimension as the length in the longitudinal direction of the frame member 1c is cut at equal intervals by cutting or the like, and the internal reinforcing member 5a is inserted into the notch by inserting the internal reinforcing member 5a in a direction perpendicular to the weld line. Formed. Since the internal reinforcement member 5 is self-supporting, the internal reinforcement member 5 and the frame members 1a and 1c are not particularly connected, and the frame member 1a is opposed to the frame member 1c with the internal reinforcement member 5 inserted therein. The frame members 1a and 1c are connected by MIG welding in a state where a part thereof is determined by the height of the internal reinforcing member 5, that is, overlapped fillet welding is performed, thereby closing the welded structure having a height of 100 mm. A cross section frame was created. Further, MIG welding was performed by a normal MIG welding machine using an A4043WY welding wire having a wire diameter of 1.2 mm.

  Further, as Reference Test Example 6 of the present invention, a welded structure closed cross-section frame according to the above-described sixth reference example shown in FIG. 9 was prepared. Cut the A6063-T5 aluminum alloy mold extrusions with a side of 80 mm and a wall thickness of 2.5 mm to a length of 85 mm, and connect the cut mold extrusions side by side by MIG welding. An internal reinforcement 6 was formed. The frame member 1c is opposed to the frame member 1a with the internal reinforcement member 6 inserted therein, and the frame members 1a and 1c are overlapped by MIG welding with a part of the overlap determined by the height of the internal reinforcement member 6. Connection, that is, overlapped fillet welding was performed, thereby creating a closed cross-section frame having a height of 100 mm. Further, MIG welding was performed by a normal MIG welding machine using an A4043WY welding wire having a wire diameter of 1.2 mm.

  The above-mentioned Examples, Reference Test Examples 1 to 6 and Comparative Examples 1 to 2 were evaluated by a compression test in the longitudinal direction (longitudinal direction) of the welded structure closed section frame using a 100 ton universal material testing machine. The compression test was finished when each welded structure closed section frame was compressed by 100 mm, and when the total length of each welded structure closed section frame reached 400 mm, the fracture state of each welded structure closed section frame was observed.

  As a result, the welded structure closed section frame of Comparative Examples 1 and 2, that is, the welded structure closed section frame in which the internal reinforcing material 2 is not installed on the inside, is welded when a longitudinal compression load is applied by a universal material testing machine. The welded part of the structural closed section frame was deformed so as to be recessed inside, opened at the welded part, and fractured.

  12 is a schematic perspective view showing a fracture state of the welded structure closed section frame of Comparative Example 2, FIG. 13 (a) is a sectional view taken along the line AA in FIG. 12, and FIG. 13 (b) is a sectional view taken along the line BB. FIG. 12 and 13, the same components as those in FIGS. 1 to 11 are denoted by the same reference numerals, and detailed description thereof is omitted. In particular, in the welded structure closed section frame having the lap joint of Comparative Example 2, since stress concentrates at the intersection of the interface between the upper plate and the lower plate and the weld metal part, as shown in FIG. A large opening was formed at the part, and fractured. The welded structure closed section frame having the butt joint of Comparative Example 1 also did not open as much as the welded structure closed section frame of Comparative Example 2 although the stress concentrated in the vicinity of the weld and fractured.

  On the other hand, in the welded structure closed section frame of Reference Test Examples 1 and 2, that is, the welded structure closed section frame in which the internal reinforcing material 2 is connected to the inside, the welded portion is deformed into a convex shape as shown in FIG. Although the metal cracked, the joint did not break and did not open greatly. 15 is a cross-sectional view taken along line AA in FIG. 14 and 15, the same components as those in FIGS. 1 to 13 are denoted by the same reference numerals, and detailed description thereof is omitted.

  Further, in Examples and Reference Test Examples 3 to 6, there was no large opening fracture at the welded part of the frame in any welded structure closed section frame. However, as in Reference Test Example 3, the inner reinforcing member 3 and the frame member 1a connected by MIG welding only on the side surface of the U-shaped frame are the portions of the frame in contact with the inner reinforcing member 3. Although the welded portion was not broken, the welded portion of the frame was broken between the internal reinforcing material 3 and the internal reinforcing material 3. However, there was no large opening as shown in FIG.

  The welded structure closed cross-section frame of Reference Test Example 4 has the same internal reinforcing material 3 as in Reference Test Example 3, and the internal reinforcing material 3 and the frame member 1a are connected in a U-shape as in Reference Test Example 3. The inner reinforcing material 3 and the frame member 1a are welded by MIG welding only on the bottom surface of the U-shaped frame member 1a, instead of being welded only by the MIG welding on the side surface of the frame. In Reference Test Example 4, the side surface (the side surface of the U-shaped frame) where the welded portion of the frame was deformed into a convex shape, but the welded portion opened greatly as shown in FIG. 12, and did not break.

  Further, in the closed cross-sectional frame of the welded structure of Reference Test Example 6, as shown in FIG. 16, the wall surface of the internal reinforcing member 6 was deformed in a U-shape, but before and after the most greatly deformed part (part A shown in FIG. 16). However, the welded part of the frame was not deformed so as to be recessed inward. That is, the internal reinforcing member 6 is also deformed simultaneously with the longitudinal compression deformation of the welded structure closed section frame, and the portion A shown in FIG. 16 is in contact with the frame members 1a and 1c so that the welded portion of the frame is not deformed inward. Therefore, the breakage (cracking) was the smallest among Examples, Reference Test Examples 1 to 6 and Comparative Examples 1 to 2.

  In a welded structure closed cross-section frame that forms a closed cross-section by welding two aluminum alloy frame members having an open cross-section, the inner reinforcing material is in contact with the inner surface of the frame member inside the welded structure closed cross-section frame When the external force is applied to the frame at the time of a collision and the like, the two welded frame members do not open greatly at the welded part, so there is no decrease in the absorbed energy at the time of the collapse and a sharp opening There is no risk of damaging the occupant and the surrounding environment due to the exposed fracture surface.

1a, 1b, 1c; frame member 2, 3, 4, 5, 6; internal reinforcing material 5a; internal reinforcing member 5b; plate material

Claims (3)

In a closed cross-section frame having a closed cross-section structure by welding two open end frames of two aluminum alloy frame members having an open cross-section, an internal reinforcing material is disposed inside, and the internal The reinforcing member is disposed inside the plate member arranged in the longitudinal direction of the frame member, and the plate member is cut at a predetermined interval and inserted into the cut so that the surface is perpendicular to the surface of the plate member. And a plurality of reinforcing members, wherein the reinforcing members are in contact with opposing side surfaces where welded portions of the frame members are present. The welded structure closed section frame according to claim 1, wherein the two aluminum alloy frame members are welded together by a butt joint. The welded structure closed section frame according to claim 1, wherein the two aluminum alloy frame members are welded by a lap joint.

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