JP6162397B2 - Differential thickness material and cylindrical member using the same - Google Patents

Description

  The present invention relates to a differential thickness material and a cylindrical member using the same, and more particularly to a differential thickness material that can be applied to a strength member of a vehicle body of a vehicle such as an automobile and a cylindrical member using the same.

  In recent years, body parts and chassis parts in vehicles such as automobiles have been welded with a plurality of plate members made of the same or different metals and having different plate thicknesses so that the required strength can be achieved while reducing weight. A differential thickness material as an integral member is used.

  Since such a differential thickness material is formed by welding a plurality of metal plate members to form an integral member, it is required to maintain a high strength and reliability of the welding.

  Under such circumstances, Patent Document 1 discloses that when a metal plate having a different plate thickness is butted and laser-welded, the dent formed on the lower surface of the weld bead is eliminated, and even if there is a gap in the butted portion, the welding energy loss is reduced. It is related with the laser butt-welding method which can weld the tailored blank material which is good shape | mold with low power consumption, high productivity, without producing. Specifically, the two surfaces of the two plate members having different thicknesses are abutted with each other in a state of being shifted from each other, and the laser light is applied to the step side where the surfaces of the one of the two members are displaced from each other along the abutting line. In a laser welding method in which a laser beam and a plate member are relatively moved while welding, a configuration is disclosed in which the welding speed is changed during welding while irradiating all the laser beams to the thick plate member.

JP 2006-218497 A

  However, according to the study of the present inventor, in Patent Document 1, it takes place along a butt line that is butted so as to present a step by shifting one surface of two plate members having different plate thicknesses from each other. A structure in which the laser beam and the plate member are relatively moved while irradiating the laser beam on the step side and welding is performed, and all the laser beams are irradiated to the thick plate member and the welding speed is changed during welding. Because it is adopted, it is not intended to suppress the formation of a sharp step on the welding surface on the step side, and to form the welding surface on the opposite side on a flat surface where no recess is formed. However, in such a welding method, forming such a weld surface on the opposite side as a flat surface where no recess is always formed tends to be difficult in practice and there is room for improvement.

  Furthermore, according to the study of the present inventor, it may be required to form a cylindrical member using a plate member after welding. Not teaching.

  The present invention has been made through the above-described studies, and a welded portion of a differential thickness material in which one surface of plate members having different plate thicknesses is flush and the other surface has a stepped shape is flush with the flush side. An object of the present invention is to provide a differential thickness material that is reliably recessed and is not unnecessarily projected on the surface on the step side, and a cylindrical member using the same.

In order to achieve the above object, in the first aspect of the present invention, a first plate member having a first plate thickness, and a second plate thickness smaller than the first plate thickness, A second plate member that is adjacent to the first plate member on one side in a first direction, and a first weld that connects the first plate member and the second plate member; The first plate member has the first plate thickness in a second direction orthogonal to the first direction, and the first plate member has a first plate member on one side in the second direction. having a first surface, said second plate member, front SL which has a plate thickness of the second Te second direction odor, said second plate at said one side of the said second direction having a first surface member, said front Symbol first surface of the first surface and the second plate member of said first plate member is flush with one another, said first The plate member has a second surface of the first plate member on the other side in the second direction, the second plate member, the at the other side in the second direction A second surface of the second plate member, and the second surface of the first plate member protrudes from the second surface of the second plate member, welds, towards the said front Symbol first surface of the first surface and the second plate member of the first plate member upward, and said second surface of said first plate member and in a state where the front Stories second surface of the second plate member facing downward, the contact portion between the second plate member and the first plate member is formed by laser welding, The third surface of the first welded portion on the one side in the second direction is the first surface of the first plate member and the first surface of the second plate member. More than Is, the fourth surface of the first weld at the other side in the second direction is the inclined surface on which the third surface is protruded toward a direction that is Ochii設A differential thickness material is prepared, and the differential thickness material is arranged in the first direction so that the first surface of the first plate member and the first surface of the second plate member are outside. When manufacturing the cylindrical member of the cylindrical member in which the opposite ends of the cylindrical member obtained by winding around an axis in a direction parallel to the cylindrical member are connected by a second welded portion, A first roller portion having a first diameter is applied to the second surface of the first plate member, and a second larger diameter than the first diameter is applied to the second surface of the second plate member. A second roller portion having a diameter of 2 is applied, and the first roller portion and the second roller portion are integral rollers.

  In addition to the first aspect, the second aspect of the present invention is that the second plate member side of the first welded portion exhibits a concave boundary line with respect to the second plate member. Let it be a situation.

According to the configuration in the first aspect of the present invention, the differential thickness member has the first plate member having the first plate thickness, the second plate thickness smaller than the first plate thickness, A first plate member that is adjacent to one plate member on one side in the first direction, and a first weld that connects the first plate member and the second plate member. The plate member and the second plate member have respective plate thicknesses in a second direction orthogonal to the first direction, and each has a first surface on one side in the second direction, The first surfaces of each of the first plate member and the second plate member are flush with each other, and the first plate member and the second plate member are respectively on the other side in the second direction. And the second surface of the first plate member protrudes from the second surface of the second plate member, and the first welded portion includes the first plate member and the second plate member. Each plate member With the second surface of each of the first plate member and the second plate member facing downward, between the first plate member and the second plate member. The third surface of the first welded portion on one side in the second direction is formed by laser welding the contact portion, and the first surface of the first plate member and the second plate member The fourth surface of the first welded portion on the other side in the second direction is an inclined surface that protrudes in the direction in which the third surface is recessed. Accordingly, the welded portion of the differential thickness material in which one surface of the plate members having different plate thicknesses is flush and the other surface has a stepped shape is reliably recessed on the flush surface side, and the step side In addition, it is possible to realize a differential thickness material that is not unnecessarily projected on the surface, and the differential thickness material can be processed into a cylindrical member using a simple post-process. Further, the cylindrical member winds the differential thickness material around an axis in a direction parallel to the first direction so that the first surfaces of the first plate member and the second plate member are on the outside. By having the configuration in which the opposite ends of the cylindrical member obtained by turning are connected by the second welded portion, the outer peripheral surface of the cylindrical member does not have a portion protruding outwardly unnecessarily. Can be obtained as a thing. Furthermore, when producing such a cylindrical member, the first roller part having the first diameter is applied to the second surface of the first plate member, and the second surface of the second plate member A second roller portion having a second diameter larger than the first diameter is applied to the first roller portion, and the first roller portion and the second roller portion are integral rollers. The cylindrical member which does not have can be obtained reliably.

  Moreover, according to the structure in the 2nd aspect of this invention, the 2nd board member side of a 1st welding part exhibits the boarder from which a board thickness differs by exhibiting a concave boundary line with respect to a 2nd board member. It is possible to reliably increase the weld area of the weld between the members and increase the weld strength.

The structure of the differential thickness material in the embodiment of the present invention is shown, FIG. 1A is a top view of the differential thickness material in the present embodiment, FIG. 1B is AA of FIG. It is sectional drawing. It is the elements on larger scale of FIG.1 (b). It is a schematic side view of the welding apparatus which welds the preform | base_material of the difference thickness material in this embodiment. It is a top view which shows the middle process which bends the difference thickness material in this embodiment with a bending apparatus. 4 is a cross-sectional view, FIG. 5A is a cross-sectional view taken along the line BB in FIG. 4, and FIG. 5B is a cross-sectional view taken along the line CC in FIG. It is a perspective view of the upper roller of the bending apparatus which bends the difference thickness material in this embodiment. The structure of the cylindrical member obtained from the difference thickness material in this embodiment is shown, Fig.7 (a) is a top view of a cylindrical member, FIG.7 (b) is X arrow view of Fig.7 (a). FIG.

  Hereinafter, a differential thickness material and a cylindrical member using the same according to an embodiment of the present invention will be described in detail with reference to the drawings as appropriate. In the figure, the x-axis, y-axis, and z-axis form a three-axis orthogonal coordinate system. For convenience of explanation, the positive direction of the x axis may correspond to the right direction, the negative direction of the x axis may correspond to the left direction, the positive direction of the z axis may correspond to the upward direction, and the negative direction of the z axis may correspond to the downward direction.

  First, the configuration of the differential thickness material in the present embodiment will be described in detail with reference to FIGS. 1 and 2.

  FIG. 1 shows a configuration of a differential thickness material in the present embodiment, FIG. 1 (a) is a top view of the differential thickness material in the present embodiment, and FIG. 1 (b) is an A view in FIG. It is -A sectional drawing. FIG. 2 is a partially enlarged view of FIG.

  As shown in FIG. 1, each of the differential thickness members 1 is typically made of a metal such as an iron material and has a rectangular shape when viewed from the top. A second plate member 12 adjacent to the negative direction side of the shaft and a third plate member adjacent to the positive direction side of the x axis with respect to the first plate member 10 are provided. Further, the first plate member 10 and the second plate member 12 are connected by a first welded portion 16, and the first plate member 10 and the third plate member 14 are connected by a second welded portion 18. Connected with.

  Specifically, regarding the plate thickness (thickness in the z-axis direction) of each of the first plate member 10, the second plate member 12, and the third plate member 14, the plate thickness of the first plate member 10. Is thickest, and the plate thickness of the second plate member 12 and the plate thickness of the third plate member 14 are thinner than the plate thickness of the first plate member 10. The first plate member 10, the second plate member 12, and the third plate member 14 are set to be flush with each other in the z-axis positive plane, and the first plate member 10 corresponds to the first plate member 10. The plane on the negative side of the z-axis protrudes from the plane on the negative side of the z-axis of each of the second plate member 12 and the third plate member 14 on the negative direction side of the z-axis.

  In particular, as shown in FIG. 2, the cross-sectional shape of the first welded portion 16 is more than the straight line L1 corresponding to the plane on the positive direction side of the z-axis of each of the first plate member 10 and the second plate member 12. a surface 16T on the positive side of the z-axis that is recessed on the negative side of the z-axis, and an end of the first plate member 10 on the negative side of the z-axis that is on the negative side of the z-axis The negative direction of the z-axis projecting on the negative direction side of the z-axis from the inclined straight line L2 connecting the end of the second plate member 12 on the positive direction side of the x-axis and the negative direction side of the z-axis. It has a side surface 16B. The surface 16B on the negative direction side of the z axis in the cross-sectional shape of the first welded portion 16 projects from the plane of the first plate member 10 on the negative direction side of the z axis toward the negative direction side of the z axis. There is nothing. Further, the boundary line L3 between the second plate member 12 and the first welded portion 16 is a curve that protrudes from the second plate member 12 toward the first plate member 10 on the positive side of the x axis. Is. The shape of the boundary line L4 between the first plate member 10 and the first welded portion 16 is not particularly limited, but typically, the boundary line L4 is slightly inclined toward the negative direction side of the x-axis as it becomes the negative direction side of the z-axis. . The cross-sectional shape of the first welded portion 16 is the same vertical cross-sectional shape at any position in the y-axis direction of the AA cross section.

  On the other hand, the cross-sectional shape of the second welded portion 18 is not shown in detail, but the cross-sectional shape of the first welded portion 16 is axisymmetric with respect to the z axis, that is, the left and right sides are reversed on the x axis. Shape.

  To summarize the first welded portion 16 and the second welded portion 18, the upper surface 16T of the first welded portion 16 is the first plate member 10, the second plate member 12, and the third plate member 14. The lower surface 16 </ b> B of the first welded portion 16 is formed below the lower plane end of the first plate member 10 and the second plate member 12. Although projecting downward from the plane connecting the lower right end, it is the same as or lower than the lower surface of the first plate member 10. The boundary between the second plate member 12 and the first welded portion 16 protrudes from the second plate member 12 toward the first welded portion 16. Further, the shape of the second welded portion 18 is a shape obtained by horizontally inverting the shape of the first welded portion 16. That is, the upper surface of the second welded portion 18 is recessed below the upper plane of the z-axis of each of the first plate member 10, the second plate member 12, and the third plate member 14. The lower surface of the second welded portion 18 protrudes below a plane connecting the lower right end portion of the first plate member 10 and the lower left end portion of the third plate member 14. It is located at the same level as or above the lower surface of the first plate member 10. The boundary between the third plate member 12 and the second welded portion 18 protrudes from the third plate member 14 toward the first plate member 10.

  Since the differential thickness material 1 having the above-described configuration is manufactured through a series of manufacturing steps using a welding apparatus having a predetermined configuration, the differential thickness material 1 will also be described below with respect to the manufacturing method and with reference to FIG. This will be described in detail. Such a series of manufacturing steps may be automatically performed sequentially using a control device (not shown), or may be manually performed sequentially by an operator, and these automatic steps and manual steps may be performed. You may combine suitably with a process.

  FIG. 3 is a schematic side view of a welding apparatus for welding the base material of the differential thickness material in the present embodiment.

As shown in FIG. 3, the welding apparatus 120 used when manufacturing the differential thickness material 1 includes a support leg 122 fixed on the floor FL, a mounting table 124 supported by the support leg 122, and a mounting table. Two plate-like mounting jigs 126 fixed on the negative direction side of the x-axis and the positive direction side of the x-axis on the 124, respectively, and the x-axis of the x-axis facing each other above the mounting table 124. And two welding guns 130 respectively disposed on the negative direction side and the positive direction side of the x-axis. The support legs 122, the mounting table 124, and the mounting jig 126 are typically made of a metal such as iron from the viewpoint of sufficient strength and thermal conductivity. The welding gun 130 is typically a laser welding gun from the viewpoint of sufficiently exhibiting the ability to melt a metal such as an iron material to be welded, and considering that welding is performed in the atmosphere, It is preferable to use a shielding gas in combination.

  First, the first plate member 110 of the base member 100 is placed on the mounting table 124 and the first plate member 110 is adjacent to the negative direction side of the x axis of the welding apparatus 120 having the above configuration. Then, the second plate member 112 of the base member 100 is placed on the placement jig 126, and the placement jig is adjacent to the positive direction side of the x axis of the first plate member 110. The third plate member 114 of the base member 100 is placed on 126. The first plate member 110, the second plate member 112, and the third plate member 114 in the base member 100 are respectively the first plate member 10, the second plate member 12, and the second plate member 12 in the differential thickness material 1. The third plate member 14 is prepared by cutting into a size necessary for obtaining the third plate member 14.

  At this time, the planes on the positive side of the z-axis of each of the first plate member 110, the second plate member 112, and the third plate member 114 are set to be flush with each other. The plane on the negative direction side of the z-axis of the plate member 110 protrudes closer to the negative direction side of the z-axis than the plane on the negative direction side of the z-axis of each of the second plate member 112 and the third plate member 114. Is done. At the same time, the upper part of the negative end side of the first plate member 110 on the negative side of the x axis and the positive end portion of the second plate member 112 on the positive side of the x axis are in contact with each other. A part of the first plate member 110 on the positive side on the positive side of the x-axis is in contact with the negative side of the third plate member 114 on the negative side.

  Here, a part of the lower side of the end of the first plate member 110 on the negative direction side of the x axis and the positive side of the x axis of the mounting jig 126 arranged on the negative direction side of the x axis. A gap 128 is defined between the ends. Moreover, a part of the lower side of the end portion of the first plate member 110 on the positive direction side of the x axis, and an end of the mounting jig 126 arranged on the positive direction side of the x axis on the negative direction side of the x axis. A gap portion 128 is defined between the two portions.

  Further, in this way, in a state where the base member 100 is placed on the welding apparatus 120, the welding gun 130 disposed on the negative direction side of the x axis is the negative direction side of the first plate member 110 on the negative side of the x axis. The upper part of the second plate member 112 and the end of the second plate member 112 on the positive direction side of the x axis are opposed to each other above the contacting part, and on the positive direction side of the x axis. The arranged welding gun 130 has a part on the upper side of the x-axis positive direction end of the first plate member 110 and an end of the third plate member 114 on the x-axis negative direction side. It is opposed to the upper part of the contacting part.

  As described above, when the base member 100 is placed on the welding device 120, the two welding guns 130 are respectively driven, and the laser beam speed B is respectively changed from the two welding guns 130. a region including an abutting portion in which a part of an upper end portion on the negative side of the x-axis and an end portion on the positive side of the x-axis of the second plate member 112 are in contact with each other; In a region including an abutting portion where a part of the upper side of the end portion on the positive side of the x axis of the plate member 110 and an end portion of the third plate member 114 on the negative direction side of the x axis are in contact. Irradiation is performed so as to give a predetermined heat input.

That is, the laser beam speed B emitted from the welding gun 130 disposed on the negative direction side of the x axis is the x axis of the first plate member 110 when it has a circular light beam shape with respect to the optical axis. The first plate member 110 is in contact with a contact portion where a part of the upper side end of the negative direction side of the second plate member 112 is in contact with the end of the second plate member 112 on the positive direction side of the x axis. The upper surfaces of the first plate member 110 and the second plate member 112 are irradiated so that the irradiation area of the second plate member 112 is equal to the irradiation area of the second plate member 112. Further, the laser light velocity B emitted from the welding gun 130 arranged on the positive direction side of the x axis is the x axis of the first plate member 110 when it has a circular light beam shape with respect to the optical axis. The first plate member 110 is in contact with a contact portion where a part of the upper end portion on the positive direction side of the third plate member 114 is in contact with the end portion on the negative direction side of the x axis of the third plate member 114. The upper surfaces of the first plate member 110 and the third plate member 114 are irradiated so that the irradiation area of the third plate member 114 is equal to the irradiation area of the third plate member 114. Here, each welding gun 130 is scanned at a predetermined scanning speed from one end of the base member 100 to the other end of the base member 100 in the y-axis direction. While scanning from one end of the base member 100 to the other end, the region including the corresponding contact portion in the base member 100 is irradiated.

  Thus, when each welding gun 130 has been scanned from one end of the base member 100 to the other end in the y-axis direction, that is, each welding gun 130 is When the other end is reached, scanning of each welding gun 130 is stopped and irradiation of each laser beam speed B is also stopped.

  When the above manufacturing process is completed, a part of the upper side of the end of the first plate member 110 on the negative side of the x axis and the end of the second plate member 112 on the positive side of the x axis are A first welded portion 16 is formed between the first plate member 110 and a portion of the first plate member 110 on the upper side of the positive side of the x axis, and the third plate member 114 is negative on the x axis. A second welded portion 18 is formed to connect the end portion on the direction side. That is, the 1st board member 10 and the 2nd board member 12 are connected by the 1st welding part 16, and the 1st board member 10 and the 3rd board member 14 are the 2nd welding. The differential thickness material 1 shown in FIG. 1 having the configuration connected by the portion 18 is manufactured.

  Here, as shown in FIG. 2, the cross-sectional shape of the first welded portion 16 is a straight line L1 corresponding to the plane on the positive direction side of each z-axis of the first plate member 10 and the second plate member 12. And a surface 16T on the positive side of the z-axis that is recessed further toward the negative side of the z-axis, and an end on the negative direction side of the z-axis that is on the negative side of the x-axis of the first plate member 10 Of the z-axis projecting on the negative side of the z-axis with respect to the inclined straight line L2 that connects the end of the second plate member 12 to the positive side of the x-axis and the end of the negative side of the z-axis. It has a surface 16B on the negative direction side. This is because the speed of laser light B emitted from the welding gun 130 arranged on the negative direction side of the x axis is equal to a part of the first plate member 110 above the end portion on the negative direction side of the x axis, A predetermined amount of heat input is given to an area including the abutting portion where the end of the second plate member 112 on the positive side of the x-axis is in contact, and the first plate member 10 and the second plate Since the plate member 12 is melted, the material melted in this manner flows downward due to its gravity, and as a result, forms an upper surface 16T that is recessed downward in the first welded portion 16. At the same time, the lower surface 16B of the first welded portion 16 projecting downward is formed in accordance with the recessed volume. Further, at this time, since the irradiation energy of the laser beam speed B is adjusted so as to apply a predetermined heat input amount, the lower surface 16B projecting downward in the first welded portion 16 has the first surface 16B. The plate member 10 is not projected below the plane on the negative side of the z axis.

Further, at this time, the lower part of the end of the first plate member 110 on the negative direction side of the x-axis and the positive direction of the x-axis of the mounting jig 126 arranged on the negative direction side of the x-axis. A gap portion 128 is defined between the first plate member 110, the second plate member 12, and the mounting jig 126 around the gap portion 128. Therefore, the amount of heat applied by the laser beam speed B is accumulated in the gap portion 128, and the temperature of the gap portion 128 is changed to the ambient temperature. The temperature becomes higher than the temperature of the member. As a result, the temperature of the end of the second plate member 12 on the positive side of the x axis and the negative side of the z axis rises, and on the positive side of the second plate member 12 on the positive side of the x axis. Since the temperature at the end on the positive direction side of the z-axis is originally on the irradiation side of the laser beam speed B, the temperature is originally high. Therefore, the second plate member 12 and the first plate member 12 in the cross-sectional shape of the first weld 16 are used. The boundary line L3 with the welded portion 16 is a curved line projecting from the second plate member 12 toward the first plate member 10 on the positive side of the x axis. On the other hand, since the lower part of the end portion on the negative direction side of the x-axis of the first plate member 110 is a vertical wall portion, the first welded portion is hardly affected by the temperature increase of the gap portion 128. The shape of the boundary line L4 between the first plate member 10 and the first welded portion 16 in the cross-sectional shape of 16 is not particularly limited, but typically, the negative direction of the x-axis becomes closer to the negative direction side of the z-axis. Slightly inclined to the side.

  Moreover, since the 2nd welding part 18 is formed similarly to the 1st welding part 16, the cross-sectional shape of the 2nd welding part 18 is the cross-sectional shape of the 1st welding part 16 with respect to az axis. The shape is line-symmetric, that is, the left and right sides are reversed on the x axis.

  Note that the amount of heat input required by the laser beam speed B may be small if the temperature of the base member 100 increases, so that the laser beam speed B scans from one end of the base member 100 to the other end in the y-axis direction. You may set so that irradiation energy of the laser beam speed B may be gradually reduced as it progresses.

  Now, since it is possible to manufacture a cylindrical member from the differential thickness material 1 manufactured as described above, using a bending apparatus having a predetermined configuration, hereinafter, for such a cylindrical member and a method for manufacturing the same, Further details will be described with reference to FIGS. Such bending may be automatically performed sequentially using a control device (not shown), or may be manually performed sequentially by an operator, and these automatic processes and manual processes may be performed. May be combined as appropriate.

  FIG. 4 is a top view showing an intermediate step of bending the differential thickness material in the present embodiment by a bending apparatus. 5 shows a cross-sectional view of FIG. 4, FIG. 5 (a) is a cross-sectional view taken along the line BB of FIG. 4, and FIG. 5 (b) is a cross-sectional view taken along the line CC of FIG. FIG. 6 is a perspective view of an upper roller of a bending apparatus for bending a differential thickness material in the present embodiment. Moreover, FIG. 7 shows the structure of the cylindrical member obtained from the difference thickness material in this embodiment, FIG.7 (a) is a top view of a cylindrical member, FIG.7 (b) shows FIG. It is a X arrow directional view of a).

  As shown in FIGS. 4 and 5, the bending apparatus 140 used when bending the cylindrical member 2 includes an upper roller 150 and a lower roller 160 that is below the upper roller 150 and faces the upper roller 150. . The upper roller 150 and the lower roller 160 are typically metal pressing members that are rotatable about the x-axis direction as a rotation axis, and the differential thickness material 1 can be inserted between them. In particular, as shown in detail in FIGS. 4 and 6, the upper roller 150 includes a small-diameter portion 150 </ b> S and large-diameter portions 150 </ b> L integrally provided at both ends thereof. The lower roller 160 has a cylindrical shape with a constant diameter.

  For the bending apparatus 140 having the above configuration, first, the end of the differential thickness material 1 on the negative direction side of the y-axis is inserted between the upper roller 150 and the lower roller 160. At this time, the surface of the differential thickness material 1 where the first plate member 10, the second plate member 12, and the third plate member 14 are flush with each other faces the peripheral surface of the lower roller 160. The portion of the first plate member 10 of the differential thickness material 1 is inserted correspondingly between the small diameter portion 150S of the upper roller 150 and the lower roller 160, and the second plate member 12 and the third plate 3 of the differential thickness material 1 are inserted. Each part of the plate member 14 is inserted correspondingly between each large-diameter portion 150L of the upper roller 150 and the lower roller 160.

Here, as shown in FIGS. 5A and 5B, the upper roller 150 is rotated clockwise in the drawing, the lower roller 160 is rotated counterclockwise in the drawing, and Since a predetermined rotational speed difference is given between them, the portion of the first plate member 10 of the differential thickness material 1 is inserted correspondingly between the small diameter portion 150S of the upper roller 150 and the lower roller 160. In addition, the differential thickness material in which the portions of the second plate member 12 and the third plate member 14 of the differential thickness material 1 are inserted correspondingly between the large diameter portions 150L of the upper roller 150 and the lower roller 160, respectively. 1 is sent toward the negative side of the y-axis while both surfaces abut against and press against these peripheral surfaces, and when it is sent from between the upper roller 150 and the lower roller 160, it is uniform. It is bent upwards while giving curvature. At this time, in the upper roller 150, the peripheral speed of the small diameter portion 150 </ b> S and the peripheral speed of each large diameter portion 150 </ b> L are the same, and they are set larger than the peripheral speed of the lower roller 160 at a predetermined rate. .

  When the differential thickness material 1 has been inserted between the upper roller 150 and the lower roller 160 and the differential thickness material 1 has been delivered from between the upper roller 150 and the lower roller 160, the differential thickness material 1 is The member is curved so as to have an axis parallel to the axis as the central axis, and has a cylindrical shape that does not have an unnecessary outwardly protruding portion on the outer peripheral surface thereof. However, at this time, the opposite ends of the cylindrical member may be spaced apart with a certain gap in the circumferential direction.

  Furthermore, finally, the opposite end portions of the cylindrical member are welded over the entire length in the x-axis direction using a welding device (not shown) while appropriately adjusting the distance between them. A cylindrical member 2 shown in FIG. 7 (a) and FIG. 7 (b) is obtained. Here, in the cylindrical member 2, the second plate member 12 and the third plate member 14 correspond to both ends of the first plate member 10 by the first welded portion 16 and the second welded portion 18. The second cylindrical member 212 and the third cylindrical member 214 are connected to the first welded portion 216 and the first cylindrical member 210 at both ends of the first cylindrical member 210 corresponding to the configuration of the differential thickness material 1 welded in this manner. 2 are welded correspondingly at the welded portion 218, are welded at the welded portion W over the entire length in the x-axis direction, and are cylindrical cylindrical members having the x-axis direction as the central axis C, The outer peripheral surface does not have a step protruding outwardly unnecessarily. Further, when forming such a welded portion W, the outer peripheral surface of the member having a cylindrical shape before the formation does not have an unnecessary protruding portion, so that the formation is simple and reliable. To be done.

  In the above configuration, the number of plate members having different plate thicknesses is not limited to three, and may be set to two or four or more as necessary.

  Further, regarding the upper roller 150, if the peripheral speed of the small diameter portion 150S and the peripheral speed of each large diameter portion 150L that are equal to each other are set smaller than the peripheral speed of the lower roller 160 by a predetermined ratio, the inner peripheral surface of the upper roller 150 is unnecessarily removed. Of course, it is possible to obtain a member having a cylindrical shape that does not have a step projecting in the direction. Moreover, since the diameter of the outer peripheral surface of the member having such a shape is not constant, the welding process at the time of welding both ends tends to be complicated, so that a cylindrical member is obtained by welding it. It is something that can be done.

As described above, according to the configuration of the present embodiment, the differential thickness member 1 has the first plate member 10 having the first plate thickness and the second plate thickness that is thinner than the first plate thickness, A second plate member 12 that is adjacent to one plate member 10 on one side in the first direction, a first welded portion 16 that connects the first plate member 10 and the second plate member 12, and The first plate member 10 and the second plate member 12 have respective plate thicknesses in a second direction orthogonal to the first direction, and are each first on one side in the second direction. The first surfaces of the first plate member 10 and the second plate member 12 are flush with each other, and the first plate member 10 and the second plate member 12 are Each of the other sides in the second direction has a second surface, and the second surface of the first plate member 10 protrudes from the second surface of the second plate member 12, and the first surface The welded portion 16 faces the first surface of each of the first plate member 10 and the second plate member 12 upward, and the second of each of the first plate member 10 and the second plate member 12. Formed by laser welding the contact portion between the first plate member 10 and the second plate member 12 in a state where the surface of the first plate member 10 is directed downward, and the first portion on one side in the second direction. The third surface 16T of the first welded portion 16 is recessed from the first surfaces of the first plate member 10 and the second plate member 12, and the first surface on the other side in the second direction. Since the fourth surface 16B of the welded portion 16 is an inclined surface projecting in the direction in which the third surface 16T is recessed, one of the plate members 10, 12, and 14 having different plate thicknesses. The welded portions 16 and 18 of the differential thickness material 1 having the same surface and the other surface having a stepped shape are reliably recessed on the surface 16T side, The differential thickness material 1 that is not unnecessarily projected on the step-side surface 16B can be realized, and the differential thickness material 1 is processed into the cylindrical member 2 using a simple post-process. Can do.

  Moreover, the 2nd board member 12 side of the 1st welding part 16 exhibits the concave boundary line L3 with respect to the 2nd board member 12, between plate members 10, 12, 14 from which board thickness differs. The weld area of the welds 16 and 18 can be reliably increased, and the weld strength can be increased.

  In addition, the cylindrical member has an axis in a direction parallel to the first direction such that the first thickness of the differential thickness material 1 is on the outer side of the first plate member 10 and the second plate member 12. By being the structure which connected the edge parts which the cylindrical member obtained by winding around each other was connected by the 2nd welding part W, the outer peripheral surface of this cylindrical member 2 protruded outside unnecessary. It can be reliably obtained as having no part.

  Further, when the cylindrical member manufacturing method manufactures such a cylindrical member, the first roller member 150S having the first diameter is applied to the second surface of the first plate member 10, and A second roller portion 150L having a second diameter larger than the first diameter is applied to the second surface of the second plate member 12, and the first roller portion 150S and the second roller portion 150L are integrated rollers. By being 150, the cylindrical member 2 which does not have the part which protruded to the exterior unnecessarily can be obtained reliably.

  In the present invention, the shape, arrangement, number, and the like of the members are not limited to the above-described embodiments, and the constituent elements thereof are appropriately replaced with those having the same operational effects, and the gist of the invention is not deviated. Of course, it can be appropriately changed within the range.

  As described above, in the present invention, the welded portion of the differential thickness material in which one surface of plate members having different plate thicknesses is flush and the other surface has a stepped shape is surely depressed on the flush surface side. It is possible to provide a differential thickness material and a cylindrical member using the same, which are provided and are not unnecessarily projected on the surface on the step side. It is expected that the present invention can be applied to the field of front structural strength members of a vehicle body such as a vehicle.

DESCRIPTION OF SYMBOLS 1 ... Differential thickness material 2 ... Cylindrical member 10 ... 1st board member 12 ... 2nd board member 14 ... 3rd board member 16 ... 1st welding part 16T ... Upper surface 16B ... Lower surface 18 ... 2nd welding Part 100 ... Base member 110 ... First plate member 112 ... Second plate member 114 ... Third plate member 120 ... Welding device 122 ... Support leg 124 ... Placing table 126 ... Placing jig 128 ... Gap portion 130 ... Welding gun 140 ... bending apparatus 150 ... upper roller 150S ... small diameter part 150L ... large diameter part 160 ... lower roller 210 ... first cylindrical member 212 ... second cylindrical member 214 ... third cylindrical member 216 ... 1st welded part 218 ... 2nd welded part W ... welded part FL ... floor C ... central axis L1 ... straight line L2 ... inclined straight lines L3, L4 ... boundary line

Claims (2)

A first plate member having a first plate thickness;
A second plate member having a second plate thickness that is less than the first plate thickness and adjacent to the first plate member on one side in a first direction;
A first weld that connects the first plate member and the second plate member;
With
The first plate member has the first plate thickness in a second direction orthogonal to the first direction, and the first plate member has a first thickness on one side in the second direction. of having a face, said second plate member, along with the pre-SL has a thickness the second plate Te second direction odor, of the said at said one side of the second direction the second plate member having a first surface, the front Symbol first surface of the first surface and the second plate member of said first plate member is flush with one another,
Said first plate member has a second surface of the first plate member on the other side in the second direction, the second plate member, of the other in the second direction A second surface of the second plate member on the side , wherein the second surface of the first plate member protrudes from the second surface of the second plate member;
The first weld, toward the front Symbol first surface of said first of said first plate member side and the second plate member upward, and the said first plate member first the second face and the front Stories second face of the second plate member in a state of facing downward, the laser welding the abutting portion between the said first plate member and the second plate member Formed by
The third surface of the first welded portion on the one side in the second direction is the first surface of the first plate member and the first surface of the second plate member. Than laid down,
It said fourth face of said first welds at the other side in the second direction, the third surface is an inclined surface that protrudes toward a direction that is Ochii設different thickness Prepare the materials,
The difference thickness material is formed on an axis in a direction parallel to the first direction so that the first surface of the first plate member and the first surface of the second plate member are outside. When producing the cylindrical member of the cylindrical member in which the opposite ends of the cylindrical member obtained by winding around are connected by a second weld, the first plate member A second roller having a second diameter larger than the first diameter is applied to the second surface of the second plate member by applying a first roller portion having a first diameter to the second surface. A cylindrical member manufacturing method in which the first roller portion and the second roller portion are integral rollers. The method for producing a cylindrical member according to claim 1, wherein the second plate member side of the first welded portion exhibits a concave boundary line with respect to the second plate member.

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