JP2012148332A - Method of manufacturing tailored blank material - Google Patents

Abstract

The present invention provides a method for producing a tailored blank material that can uniform a gap between two blank materials to be joined and joined in the direction of the weld line and ensure welding accuracy and quality even when the weld line is curved. .
SOLUTION: Two blank materials P11 and P12 for which cutting margins for cutting edges S1 and S2 are anticipated are prepared in advance, and the cutting margins for cutting edges S1 and S2 are mutually exceeded on both sides of the abutting portion during welding. The blanks P11 and P12 are simultaneously cut with the portion corresponding to the abutting portion as a cutting line 8 in a state of being overlapped so as to be wrapped. Cut ends 3 and 4 corresponding to the cutting lines 8 of the respective plate materials P1 and P2 after cutting excluding the cut ends S1 and S2 are butted together, and laser welding is performed using the butted portion as a welding line.
[Selection] Figure 1

Description

  The present invention relates to a method for manufacturing a tailored blank formed by welding different types of plate materials in combination.

  Tailored blanks made by molding a plurality of plate materials (thin metal plates such as steel plates) with different thicknesses, materials, or strengths and joining them together by laser welding or the like as molding elements for automobile body parts Materials may be used. In particular, steel plates having different thicknesses that are joined together and welded together are also called differential thickness steel plates or differential thickness blank materials. By press-molding car body parts into the required shape using such a tailored blank material, the necessary parts can have the necessary thickness, material, or strength, and the car body parts themselves and thus the weight of the entire car body It is said that it can contribute to

  For example, in order to manufacture a tailored blank material in which two plate materials having different plate thicknesses are butted and joined together, laser welding is performed after the cut surfaces of one plate material and the other plate material which are cut separately are butted together. 1 and 2 of Patent Document 1 disclose a plate cutting method that involves generation of a cut material and a plate cutting method that does not involve generation of a cut material.

Japanese Patent No. 4435921

  However, in the conventional method as typified by the above-mentioned Patent Document 1, it is not possible to simply butt the cut edges of one plate material and the other plate material cut separately (in many cases, cut with separate cutting blades). In addition, a gap may be generated at the abutting portion, or the gap is likely to be non-uniform in the weld line direction, and subsequent welding accuracy and welding quality may not be stable, and welding defects such as unwelding may occur. This tendency is particularly noticeable when the weld line that is the butt portion between both plate materials is other than a straight line, particularly when the weld line is curved, and each plate material was prepared individually. Since it is necessary to cut with separate cutting dies, the equipment cost increases, which is not preferable.

  Further, the method described in FIG. 1 of Patent Document 1 is effective in improving the material yield because there is no generation of cut material, but as described above, the butt portion between both plate materials This is applicable only when the weld line is a straight line, and when the weld line is other than a straight line, especially when the weld line has a complicated shape such as a curve, the welding accuracy and welding There is still room for improvement in terms of quality improvement.

  The present invention has been made paying attention to such a problem, and gives priority to the improvement of welding accuracy and welding quality by accepting the generation of cutting material, and in particular, the welding line is other than a straight line such as a curve. It is an object of the present invention to provide a tailored blank material manufacturing method that is considered so as to ensure stable welding accuracy and welding quality even in the case of a complex shape.

  The invention according to claim 1 is a method of manufacturing a tailored blank material formed by abutting and welding at least two plate materials, and comprising two independent plate materials that allow for a cutting margin for the cut end material. Prepare both in advance, and on both sides of the abutting part at the time of welding, the two plate members are overlapped with each other so as to overlap each other by the cutting margin for the cut end material, and the parts corresponding to the above-mentioned abutting part are used as a cutting line for both plate materials Are cut at the same time, the cut edges corresponding to the cutting lines of the respective plate materials after cutting except for the cut end material are butted together, and welding is performed using the butted portion as a welding line.

  In this case, as described in claim 2, the cutting line (welding line) is assumed to have a shape other than a straight line, for example, a curved shape, a V shape or a crank shape, and welding. As for the method, any method such as carbon dioxide welding, plasma welding, MIG welding, and mash seam welding may be used as long as a butt joint can be achieved as a welding joint.

  Furthermore, in consideration of productivity and simplicity of equipment, the simultaneous cutting of the two plate members is a press shearing process using a common cutting blade such as shear cutting or blanking as described in claim 3. Is preferred. However, when the cutting line is a complicated curved line, as described in claim 4, it may be a cutting process using a laser.

  Therefore, in at least the invention described in claim 1, the cut ends of both plate materials cut at the same time in a superposed state are brought into contact with each other, and then welding is performed, so that both the cut ends to be welded lines can be accurately aligned. As a result, gaps and non-uniformities are less likely to occur, leading to stabilization of welding accuracy and welding quality.

  According to the first aspect of the present invention, it is possible to suppress the generation of a gap in the butt joint which is a welded joint, to stabilize the welding accuracy and the welding quality, and to cut the plate material. The cost of equipment can be reduced at the same time.

Process explanatory drawing which shows the specific form for enforcing the manufacturing method of the tailored blank material which concerns on this invention. It is sectional drawing of the tailored blank material after welding, and is an expanded sectional view which follows the QQ line in (E) of FIG. The expanded sectional view when the cut ends of both board | plate materials are faced | matched. Cross-sectional explanatory drawing of the main part of a blanking press die that functions as a cutting die. Explanatory drawing which shows the modification of the cutting line in the manufacturing method of the tailored blank material which concerns on this invention.

  1-4 is a figure which shows the more concrete form for enforcing the manufacturing method of the tailored blank material which concerns on this invention, and especially FIG. 1 is a series of processes until the tailored blank material W which became one sheet is obtained. An explanatory diagram is shown.

  As shown in FIG. 1D, two deformed rectangular plate materials (for example, steel plates) P1 and P2 that are blanked or precut in advance and are independent of each other are prepared. As shown in FIG. 2, one plate P1 has a relatively small plate thickness t1, the other plate P2 has a relatively large plate thickness t2, and the relationship between the plate thicknesses t1 and t2 is t1 <t2. In addition, the end faces of both plate materials P1 and P2 are finally abutted against each other and aligned and matched to individually form curved cuts 3 or 4 as abutting surfaces to be welded lines. It is.

  Then, as shown in FIG. 1E and FIGS. 2 and 3, the cut ends 3, 4 of both plate materials P 1, P 2 are butted to each other and then subjected to laser welding, and the butted portion of the cut edges 3, 4 is set as the butted portion By continuously performing laser welding in the form of a butt joint as a weld line, a rectangular flat plate tailored blank material W made of two plate materials P1 and P2 having different plate thicknesses is obtained. In addition, the code | symbol Be of (E) of FIG. 1 shows the bead part formed by performing laser welding to the butt | matching surface of cut | intersection 3,4.

  The tailored blank W obtained in this way is used, for example, as a pressing material for automobile body parts and the like, and is formed into a required three-dimensional shape by bending or drawing as is well known.

  Here, when the plate materials P1 and P2 having different plate thicknesses are cut in different processes and with different cutting dies, the matching accuracy between the cut edges 3 and 4 cannot be secured, and the cut edges are cut prior to welding. As described above, when gaps 3 and 4 are brought into contact with each other, gaps and non-uniform gaps due to variations thereof may occur and welding defects may occur.

  Therefore, in the present embodiment, when securing the matching accuracy between the cut edges 3 and 4 of both plate materials P1 and P2, the cut edges 3 and 4 are shared in a state where the base materials of both plate materials P1 and P2 are overlapped. By cutting at the same time with this cutting die, it is intended to ensure the matching accuracy between the cut edges 3 and 4.

  More specifically, as shown in FIG. 1A, as a rectangular blank material P11 that is a base material of one plate material P1, a cutting margin as a cutting material S1 is provided in the vicinity of a portion to be the cut edge 3. Is prepared in advance, and similarly, a rectangular blank material P12 serving as a base material of the other plate material P2 is preliminarily provided with a cutting margin as a cutting material S2 in the vicinity of the portion to be the cut edge 4. Prepare one of the expected size.

  And after these blank materials P11 and P12 are piled up, as shown to (B) and FIG. 4 of FIG. 1, it shall be used for the simultaneous cutting | disconnection by the common cutting die 5. FIG. The cutting die 5 shown in FIG. 4 is a so-called blanking press die, and a movable upper blade 7 that is also a cutting blade moves up and down with respect to a fixed lower blade 6 that is a cutting blade. The blank materials P11 and P12 are simultaneously cut by a shearing action based on the engagement between the two. Note that the cutting blades 6a and 7a on the side of the lower blade 6 and the upper blade 7 both match the shape of the cut edges 3 and 4 in FIG. 1D, and a slight clearance is set between them.

  When the two blank materials P11 and P12 are overlapped with each other, as shown in FIG. 4, for example, one blank material P11 is set as the upper side, the other blank material P12 is set as the lower side, and both sides of the butted portion at the time of welding. That is, it is assumed that the blank materials P11 and P12 are overlapped on both sides of the portion to be the cut edges 3 and 4 so as to overlap each other by the cutting margins of the cut ends S1 and S2. In this state, the upper blade 7 is lowered with respect to the lower blade 6 so that one blank material P11 is the dropping side and the other blank material P12 is the remaining side, and the portion corresponding to the cut edges 3 and 4 is a cutting line. 8, both blank materials P11 and P12 are simultaneously cut (sheared).

  In this case, one blank material P11 on the dropping side tends to become unstable, so that one blank material P11 is supported by a cushion pad or the like from the lower side as necessary, or one of the blank materials P11 It is desirable to pressurize and restrain the region to be the cut material S1 from above with a pad (not shown). Also, the vertical relationship between one blank material P11 and the other blank material 12 may be reversed from that shown in FIG.

  As a result, as shown in FIGS. 1B and 1C, both blank materials P11 and P12 have cut lines 3 and 4 having the same shape with a cutting line 8 by the common cutting die 5. That is, at the same time, one plate material P1 and the cut material S1 are generated from one blank material P11, and the other plate material P2 and the cut material S2 are generated from the other blank material P12. Further, as shown in FIG. 3, “cutting” occurs on the lower surface side of the cut surface 3 of the one plate material P <b> 1 on the dropping side as a special feature of the cut surface due to shear, and a burr 3 a is generated upward. In addition, at the cut end 4 of the other plate material P2 which is the remaining side, “sag” is generated on the upper surface side and a burr 4a is generated downward.

  Thereafter, as described above with reference to FIG. 1D, the cut edges 3, 4 corresponding to the cutting line 8 of the respective plate materials P1, P2 after cutting excluding the cut ends S1, S2 are formed. Then, laser welding is performed using the butted portion as a welding line, and a tailored blank material W that is a so-called single plate as shown in FIG. As a matter of course, when the cut ends 3 and 4 are brought into contact with each other, both the plate materials P1 and P2 remain in the posture at the time of cutting and are not reversed.

  In this case, as described above with reference to FIG. 3, when the cut edges 3 and 4 of both the plate materials P1 and P2 are brought into contact with each other prior to laser welding, the burr 3a is formed on the one plate material P1 facing upward. Since the cut end 3 and the burr 4a are combined with the cut end 4 of the other plate material P2 facing downward, a V-shaped groove shape suitable for butt welding is formed in the butt portion of the two because the volume is relatively small. Will be.

  As described above, according to the present embodiment, the cuts 3 and 4 to be the butt surfaces of the two plate materials P1 and P2 are simultaneously cut by the common cutting die 5, thereby matching the cuts 3 and 4 with each other. The accuracy is remarkably improved, and it is possible to greatly suppress the occurrence of gaps and non-uniformity when they are brought into contact with each other. This means that it is possible to greatly suppress the occurrence of poor welding when laser welding is performed, and a great improvement in welding accuracy and welding quality can be expected.

  In other words, laser welding has a higher energy density in the laser beam irradiated portion than other welding methods, and the width of the bead portion Be formed is small, so the welding quality is affected by the gap variation at the butt portion anyway. Although it tends to be easy, according to the present embodiment, it is possible to prevent the occurrence of poor welding by remarkably improving the matching accuracy between the cut edges 3 and 4 of both plate materials P1 and P2, and the matching accuracy. It becomes possible.

  Here, in the form shown in FIG. 1, the case where the cutting lines 8 (welding lines) of the respective plate materials P1, P2 are curved is illustrated, but when the cutting line 8 is other than a straight line, for example, As shown in FIGS. 5A to 5D, the present invention can be applied even if the cutting line 8 has a bent shape combining straight lines or a bent shape combining straight lines and curves. It is possible to apply.

  In the previous embodiment, the cutting line 8 is cut at the same time with the common cutting die 5, but it is also possible to use laser cutting instead. For example, when the shape of the cutting line 8 is a more complicated shape such as a curve, for example, an NC control type laser processing head or a laser processing head held by an industrial robot is based on the same locus as the cutting line 8. It is good also as a system cut | disconnected by, and cut | disconnecting the two blank materials P11 and P12 which overlap | superposed simultaneously.

  Furthermore, although the example in the case where both plate materials are steel plates is shown in the previous embodiment, the present invention can naturally be applied to tailored blank materials made of the same or different types of plate materials other than steel plates. .

3 ... Cut 4 ... Cut 5 ... Blanking press die (cutting die)
6 ... Lower blade (cutting blade)
7 ... Upper blade (cutting blade)
8 ... Cutting line (welding line)
P1 ... Plate material P2 ... Plate material P11 ... Blank material (base material)
P12 ... Blank material (base material)
S1 ... Cut material S2 ... Cut material W ... Tailored blank material

Claims (4)

A method for producing a tailored blank material formed by welding at least two plate materials together,
Prepare two independent plate materials that allow for the cutting allowance for the cut ends,
In the state where two plates are overlapped on both sides of the abutting part at the time of welding so as to overlap each other by the cutting margin of the cut end material, both parts are cut at the same time using the portion corresponding to the abutting part as a cutting line. ,
A method for producing a tailored blank material, characterized in that cuts corresponding to the cutting lines of the respective plate materials after cutting excluding the cut end material are butted together and welding is performed using the butted portion as a welding line.   The method for producing a tailored blank material according to claim 1, wherein the cutting line and the welding line are other than a straight line.   The method for producing a tailored blank material according to claim 2, wherein the simultaneous cutting of the two plate members is performed by press shearing using a common cutting blade.   The method for producing a tailored blank material according to claim 2, wherein the simultaneous cutting of the two plate materials is performed by a cutting process using a laser.

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