Technical field
[0001]
The present disclosure relates to a manufacturing method and a quenching member quenching member.
BACKGROUND
[0002]
For example, Japanese Patent No. 3114918 (Patent Document 1), Japanese Patent No. 5886325 (Patent Document 2), Japanese Patent No. 3974324 Pat (Patent Document 3) Japanese Patent No. 4040840 No. the book (Patent Document 4), a method of manufacturing a hollow pipe member of metal plate is described.
[0003]
　In the manufacturing method described in Patent Document 1, by forming a longitudinal curved shape at the stage of first forming step, the cross-sectional shape in a pipe shape in a subsequent molding process.
[0004]
　In the manufacturing method described in Patent Document 2, by forming a longitudinal curved shape at the stage of first forming step as in Patent Document 1, the cross-sectional shape in a pipe shape in a subsequent molding process. Using a core as the tool for the longitudinal part of the cross-sectional shape to a rectangular shape.
[0005]
　In the manufacturing method described in Patent Documents 3 and 4, in a first processing step to form a wall having a seam in a pipe the finished body. In the second processing step, and one wall portion facing the joint, the angle between the other wall portion adjacent to the one wall portion, and an angle greater than the pipe finished body.
[0006]
　In the third processing step, to form a convex curved portion bulging outward in the first wall portion by applying an external force to the other wall. Then, in the fourth processing step, flatly deformed convex curved portion by applying an external force to the one wall portion to form a pipe body in which a pair of sides are in close contact with the spring-back force.
Summary of the Invention
Problems that the Invention is to Solve
[0007]
　In the manufacturing method described in Patent Document 1 and Patent Document 2, when the thickness of the metal plate is thick it is easy to mold. However, if a small thickness, when formed into a pipe shape curved in the longitudinal direction, buckling or wrinkles or the like is likely to occur at the curved portion.
[0008]
　When molding a cross-sectional shape to a rectangular shape, using a core in the tool, complex mold structure removing the core in the longitudinal direction is required, the cost becomes high. Furthermore, it is not possible to use the core in the entire longitudinal direction, it is difficult to maintain the cross-sectional shape of the longitudinal center portion.
[0009]
　Further, the cold working, if forming a shape which is curved in the longitudinal direction using a high-strength steel sheet, spring back after molding is increased. In this case, it is difficult to obtain a desired curved shape.
[0010]
　Further, in the manufacturing method described in Patent Documents 3 and 4, the production method of the hollow pipe member is described. However, the method of the curved shape of the hollow pipe member in the longitudinal direction is not described.
[0011]
　The present disclosure has been made in view of such problems, a member of rectangular cross-section with a hollow curved longitudinally, intended to form with good dimensional accuracy.
Means for Solving the Problems
[0012]
　In the manufacturing method of quenching member to solve the above problems, Ac3 transformation point of the steel sheet processed intermediate molded article into a rectangular cross-sectional shape in which two edges having a butted portion is butted in the same side of the steel plate comprises a heating to above, and to the heated said intermediate molded article quenched in the mold, the.
[0013]
　That is, after heating the intermediate product in which the end edges of the steel sheet is processed into a rectangular cross-sectional shape is butted than Ac3 transformation point, forming the member quenched by quenching in a mold while hot forming. Accordingly, even if the hardening member curved in the longitudinal direction is formed in the thin steel sheet, high strength, dimensional accuracy of the curved shape is good to form a hardened member which suppresses the occurrence of buckling or wrinkles be able to.
[0014]
　Furthermore, the intermediate molded article to be hardened has a substantially closed cross section. Therefore, as compared with the case of hot forming by heating the flat steel plate, hardly heat escapes from the heated intermediate product, a temperature drop can be suppressed. This makes it possible to increase the allowable time from completion of heating to the start of hot forming.
[0015]
　Therefore, to reduce the hardening failure due to a temperature drop, a highly robust manufacturing process.
Effect of the invention
[0016]
　According to the manufacturing method of quenching member of the present disclosure, the member of rectangular cross-section with a hollow curved in the longitudinal direction can be formed with good dimensional accuracy.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017]
FIG. 1 is a sectional view as seen from the front of the press showing a first step of the manufacturing method of quenching member according to the first embodiment.
It is a sectional view as seen from the front of the press showing a first step following FIG. 1; FIG.
3 is a perspective view showing a shaped molded article in the first step.
An enlarged view of a portion A of FIG. 4 FIG.
5 is a sectional view as seen from the front of the press showing a second step of the manufacturing method of quenching member according to the first embodiment.
It is a sectional view as seen from the front of the press showing a second step subsequent to FIG. 6 FIG.
7 is a perspective view showing molded article molded in the second step.
8 is a sectional view as seen from the front of the press showing a third step of the manufacturing method of quenching member according to the first embodiment.
It is a [9] a cross-sectional view as seen from the front of the press showing a third step following FIG.
Is a perspective view showing the FIG. 10 intermediate molded article molded in the third step.
11 is a schematic view showing a state viewed pressing device from the side showing the fifth step of the manufacturing method of quenching member according to the first embodiment.
Is a schematic view showing a state viewed pressing device from the side showing the FIG. 12 a fifth step subsequent to FIG. 11.
13 is a side view showing the quenching member according to the first embodiment.
An enlarged view of B part of FIG. 14 FIG. 13.
It is a C-C sectional view of FIG. 15 FIG. 14.
FIG. 16 is a partial perspective view seen from a direction D in FIG. 15.
17 is a graph showing the temperature change with respect to time from exiting furnace of the members.
18 is a diagram showing a second embodiment corresponding to a part perspective view seen from a direction D in FIG. 15.
Is a diagram showing a third embodiment corresponding to FIG. 19 partially perspective view as viewed from the D direction of FIG. 15.
Is a diagram showing a fourth embodiment corresponding to FIG. 20 partially perspective view as viewed from the D direction of FIG. 15.
DESCRIPTION OF THE INVENTION
[0018]
　(First Embodiment)
　Hereinafter, with reference to FIGS. 1 to 17, for explaining the first embodiment.
[0019]
　12 from FIG. 1 is a diagram showing a manufacturing method of quenching member according to the present embodiment, FIG. 13 is a diagram showing the quenching member 10 to be molded by the manufacturing method of the quenching member. Quenching member 10 is an elongated member, the reinforcing member can be cited as an example. The quenching member 10, with a rectangular cross-sectional shape, it is curved in the length direction NH.
[0020]
　(Steel)
　ratio of member height H of the curved direction of the tempering member 10 relative to the plate thickness T in the transverse plane (U direction) is preferably molded using a steel sheet 12 to be 40 or less. In this embodiment, a steel plate 12 of the H / T = 20 (see FIG. 15).
[0021]
　Steel used as the steel sheet 12 is a mass%, C: 0.1% or more and 0.8% or less, Si: 0.001% or more and 2.0% or less, Mn: 0.5% to 3.0% or less , P: 0.05% or less, S: containing 0.01% or less as the chemical composition. Further, steel is a mass%, sol. Al: 0.001% to 1.0% or less, N: 0.01% or less, B: 0.01% or less containing as a chemical composition, it is preferred that the balance being Fe and impurities. Further, the chemical composition, instead of a part of Fe, Ti, Nb, V, Cr, Mo, Cu, may contain one or more selected from the group consisting of Ni.
[0022]
　If the amount of carbon C is too small, can be a less effective is not so much the strength of the hardened product. Therefore, in the present embodiment, the amount of carbon contained in the steel sheet 12 was 0.1 mass% or more.
[0023]
　On the other hand, when the amount of carbon C is too large, the poor too hard toughness products. Therefore, in the present embodiment, the amount of carbon contained in the steel sheet 12, and 0.8 wt% or less, the amount of carbon contained in the steel sheet 12, and a 0.8 mass% 0.1 mass% or more.
[0024]
　Si is preferably controlled to a range of 0.001 mass% to 2.0 mass%. Elemental Si is having an effect without deteriorating the ductility to suppress the formation of carbides during cooling from the austenite phase to be transformed into low-temperature transformation phase, or to improve ductility, increasing the strength after quenching it is. Si content is less than 0.001 wt% it is difficult to obtain the above effect. Therefore, Si content is preferably 0.001 mass% or more.
[0025]
　Incidentally, the Si content, when more than 0.05 mass%, ductility is further improved. Therefore, Si content is more preferably 0.05 mass% or more. On the other hand, Si content, the 2.0 mass%, the effect of the action on the economic disadvantage saturated, deterioration of the surface properties is remarkable. Therefore, Si content is preferably 2.0 mass% or less. More preferably not more than 1.5 mass%.
[0026]
　Mn is preferably controlled to a range of 0.5 mass% to 3.0 mass%. Mn enhances the hardenability of the steel, in order to stably secure the strength after quenching, is an element with a very effective. However, Mn content is less than 0.5 mass%, the effect is insufficient even in the rapid cooling conditions, in strength after hardening, to ensure the tensile strength of at least 1200MPa very difficult Become. Therefore, Mn content is preferably 0.5 mass% or more.
[0027]
　P is preferably controlled to 0.05 mass% or less. P is generally is an impurity which is inevitably contained in the steel, the solid solution strengthening, it may actively be contained since it has an effect of improving the strength. However, P content, resistance weldability occurs with member and other members of the present embodiment is significantly in excess 0.05%. Accordingly, P content is preferably 0.05 mass% or less. P content is more preferably 0.02 mass% or less. To obtain the above effects more reliably, the P content is preferably set to 0.003 mass% or more.
[0028]
　S is preferably controlled to 0.01% by mass or less. S is an impurity which is inevitably contained in the steel combines with Mn and Ti is deposited to produce a sulfide. When the deposition amount is excessively increased surface of the deposit and the main phase is preferably as low because it can be a starting point of fracture. S content, its adverse effect becomes significant at greater than 0.01 wt%. Thus, S content is preferably 0.01 mass% or less. More preferably, 0.003 wt% or less, still more preferably not more than 0.0015 mass%.
[0029]
　sol. Al is preferably controlled in a range of 0.001 mass% to 1.0 mass%. Al is an element having an effect of consolidation steel by deoxidation of steel and also an element having an effect of improving the yield of carbonitride-forming elements such as Ti. sol. Al content, it is difficult to obtain the effect is less than 0.001 mass%. Therefore, sol. Al content is preferably 0.001 mass% or more. More preferably, not less than 0.015 mass%. On the other hand, sol. Al content is in the than 1.0 wt%, reduction in weldability with a marked, oxide inclusions deterioration of surface properties is significantly increased. Therefore, sol. Al content is preferably 1.0 mass% or less. More preferably 0.080 mass% or less.
[0030]
　N is preferably controlled to 0.01% by mass or less. N is an impurity which is inevitably contained in the steel, preferably as low from the viewpoint of weldability. N content, reduction in weldability is significantly in excess of 0.01 mass%. Therefore, N content is preferably 0.01 mass% or less. More preferably 0.006 mass% or less.
[0031]
　B is preferably controlled to 0.01% by mass or less. B is an element having an effect of improving the low temperature toughness. Therefore, it may be contained B. However, when the content exceeds 0.01 mass%, hot workability is degraded, the hot rolling becomes difficult. Therefore, B content is preferably 0.01 mass% or less. Incidentally, in order to obtain the effect of the action more reliably, the B content is more preferably 0.0003 mass% or more.
[0032]
　Other additive elements, Ti, Nb, V, Cr, Mo, Cu, and Ni, to improve the hardenability of the steel, and be added as required in order to stably secure the strength after quenching good.
[0033]
　
　In forming the hardened member 10, as shown FIGS. 1 and 2, in a first step 14 which is part of a molding process for molding the intermediate molded article, the steel plate 12 first press cold-pressed with a device 16.
[0034]
　(First configuration of the press device)
　in Figures 1 and 2 show a first press device. The first press device 16 includes a first upper mold 18 has a first lower mold 20, the first lower mold 20, the pad 22 is provided.
[0035]
　The first lower mold 20, the recess 20A which opens upward U is formed in the central portion, the bottom portion 20B of the recess 20A, there is a pad accommodating portion 20C.
[0036]
　Inner surface of the recess 20A of the first lower mold 20 has a curved portion 20E extending from the upper end face 20D of the first lower mold 20, the recess which is inclined towards the die center C towards than the curved portion 20E downward and a wall 20F. Further, the inner surface of the concave portion 20A has a concave corner 20G curved toward the lower edge of the recess wall 20F to the mold center C, the pad housing portion 20C is provided between the recess corners 20G.
[0037]
　The pad housing portion 20C of the first lower die 20, and pad 22 is provided, the pad 22 is connected to the first lower mold 20 through the pad pressing device (not shown). The pad pressing device, for example a gas cushion, a hydraulic device, a spring, is configured with the electric drive apparatus or the like, to move the pad 22 to the pressing direction is upward U or downward D with respect to the first lower mold 20.
[0038]
　Top 22A of the pad 22 is formed to be flat, as shown in FIG. 2, the bottom dead center pad 22 is housed in the pad receiving portion 20C, the recess corners 20G on an extension line of the top surface 22A the lower edge of the are located. In this state, an obtuse angle from the top surface 22A and the concave wall surface 20F of the pad 22.
[0039]
　The first upper mold 18, as shown in FIG. 1, are arranged to face the first lower mold 20, the first upper die 18 is connected to a moving device (not shown). Mobile device, for example a hydraulic device is composed of an electric drive apparatus or the like, moves the pressing direction is upward U or downward D the first upper mold 18 relative to the first lower mold 20.
[0040]
　The first upper mold 18 has a shape having a lower end corresponding to the recess 20A of the first lower mold 20, as shown in FIG. 2, lower end first lower mold of the first upper mold 18 the bottom dead center housed in the recess 20A of 20, the lower surface 18A of the first upper mold 18 is opposed to the top surface 22A of the pad 22. Further, the curved shoulder 18B forms an angle of a first upper mold 18 is opposed to the concave corners 20G of the first lower mold 20, the inclined surface 18C extending from the shoulder portion 18B in the recess wall 20F opposite. The inclined surface 18C and the recess wall 20F, there are wave-shaped unevenness (not shown).
[0041]
　(First first step by a press device)
　when molded in the first press device 16, as shown in FIG. 1, the pad 22 increases with the pad pressing device, top 22A of the pad 22 is first to maintain the same height as the upper end face 20D of one lower die 20. In this state, the sets steel sheet 12 on the top surface 22A of the pad 22, the first upper mold 18 descends in the mobile device, the steel sheet at the top face 22A of the lower surface 18A and the pad 22 of the first upper mold 18 to hold the 12.
[0042]
　Then, as shown in FIG. 2, and moves down the first upper mold 18 in the mobile device to retract the pad 22 to the pad receiving portion 20C, the first lower mold to the lower end portion of the first upper mold 18 inserting into 20 of the recess 20A (see FIG. 1).
[0043]
　Then, the steel plate 12 is pressed part top face 22A of the lower surface 18A and the pad 22 of the first upper die 18 is a flat portion 24E. Further, the steel plate 12, a shoulder portion 18B and the press portion in the recess corners 20G of the first lower mold 20 of the first upper die 18 is bent portion 24F. Further, the steel plate 12, the inclined surface 18C and the recess wall 20F pressed part of the first lower mold 20 of the first upper die 18 is a flange portion 24G.
[0044]
　(First molded article)
　Figure 3 is a diagram showing a first molded article 24 molded using the first press device 16 in the first step 14. The end of the body portion 24A of the first molded product 24, the first support portion 24B and the second support portion 24C is disconnected in the final step is provided via a narrow neck portion 24D.
[0045]
　The body portion 24A is formed in an elongated shape. The main body portion 24A includes a flat portion 24E continuous with the first supporting portion 24B and the second support portion 24C, and a bent portion 24F formed on the edge of the flat portion 24E, a flange portion 24G extending from the bent portion 24F with the door. The flat part 24E and the flange 24G of the main body portion 24A, form an obtuse angle. The first support portion 24B, the circular hole 24H has been formed, the second support portion 24C, a long hole 24I extending in the longitudinal direction NH of the first molded product 24 is formed.
[0046]
　The flange portion 24G, as shown in FIG. 4, a corrugated portion 26 formed in the first step 14 is formed at intervals in the longitudinal direction NH. Corrugation 26 is constituted by the bent portion 26A forms a curved pair so as to protrude to the opposite flange portion 24G side. And one flange portion bend corrugated comprised of 26A of 24G, and the other flange portion bend corrugated comprised of 26A of 24G, the wave form of the phase is shifted by a half period in the length direction NH there.
[0047]
　
　The first molded product 24 molded in the first step 14, as shown in FIGS. 5 and 6, the cold pressing in the second press apparatus 30 in the second step 28.
[0048]
　(Second configuration of the press apparatus)
　the second pressing device 30, as shown in FIG. 5, and a second upper mold 32 and the second lower mold 34.
[0049]
　The second lower mold 34, the recess 34A which opens upward U is formed in the central portion, the opening width of the recess 34A is narrower than the width of the flat portion 24E of the first molded product 24.
[0050]
　Inner surface of the recess 34A of the second lower mold 34 has a curved portion 34C that extends through the upper end face 34B of the second lower mold 34, the recess which is inclined towards the die center C towards than the curved portion 34C downward and a wall 34D. Further, the inner surface of the concave portion 34A is provided with a recess corners 34E curved toward the lower edge of the recess wall 34D to the mold center C. Between the two recesses corners 34E, it is provided with a flat bottom surface of the recess 34F, the bottom surface of the recess 34F and the recess wall 34D form an obtuse angle.
[0051]
　Second upper mold 32 is arranged to face the second lower mold 34, the second upper mold 32 is connected to a moving device (not shown). Mobile device, for example a hydraulic device is composed of an electric drive apparatus or the like, to move the second upper mold 32 to the pressing direction is upward U or downward D to the second lower mold 34.
[0052]
　Second upper mold 32 has a lower end portion has a shape corresponding to the concave portion 34A of the second lower mold 34. As shown in FIG. 6, the lower end portion of the second upper mold 32 is concave 34A bottom dead center housed in (see FIG. 5) of the second lower mold 34, the lower surface of the second upper mold 32 32A There facing the bottom surface of the recess 34F of the second lower mold 34. Further, the curved shoulder 32B forms an angle of the second upper mold 32 is opposed to the concave corners 34E of the second lower mold 34, the inclined surface 32C extending from the shoulder portion 32B in the recess wall 34D opposite.
[0053]
　(Second second step by a press device)
　when molding in the second press apparatus 30, as shown in FIG. 5, sets the main body portion 24A of the first molded product 24 to the second lower mold 34 , both side portions of the flat portions 24E, is supported by both sides of the upper end face 34B of recess 34A of the second lower mold 34. In this case, although not shown, for positioning the first molded product 24 using the long hole 24I of the round hole 24H and the second support portion 24C of the first support portion 24B of the first molded product 24 (see FIG. 3) . The same applies to the following pressing step.
[0054]
　In this state, as shown in FIG. 6, and moves down the second upper mold 32 in the mobile device, inserting the lower end portion of the second upper mold 32 into the recess 34A of the second lower mold 34.
[0055]
　Then, the flat portion 24E of the main body portion 24A of the first molded product 24, the lower surface 32A and pressed width recess bottom surface 34F of the second lower mold 34 of the second upper mold 32 narrow flat portion 36D is formed that. Also, the flat portion 24E, and a bent portion 36E which is pressed by the concave corners 34E of the shoulder portion 32B and the second lower mold 34 of the second upper mold 32, the inclined surface of the second upper mold 32 32C and It is pressed at the recess wall surface 34D of the second lower mold 34, and upright standing portion 36F is formed.
[0056]
　(Second molding)
　FIG. 7 shows a second molded product 36 was molded using the second press apparatus 30 in the second step 28. The body portion 36A of the second molded product 36, and the narrow flat portions 36D contiguous with the first support portion 36B and the second support portion 36C, and a bent portion 36E formed at the side edge of the narrow flat portions 36D, bent and a standing portion 36F extending from the parts 36E. Width form an obtuse angle to the narrow flat portion 36D and the upright portion 36F.
[0057]
　Edge of the flange portion 36G formed in the upstanding portion 36F (corresponding to the flange portion 24G of the first molded product 24) are spaced apart, the body portion 36A is between the flange 36G is opened.
[0058]
　Further, the main body portion 36A and the side edges of the first support portion 36B and a second and a supporting portion 36C was continuously provided side edges of the neck portion 36H and the first support portion 36B and the second support portion 36C, continuously standing portion 36F reinforcing ribs 36I is formed to have. Thus, the main body portion 36A and the first support portion 36B and the second support portion 36C and the joint portion is reinforced.
[0059]
　
　The second molded product 36 molded in the second step 28, as shown in FIGS. 8 and 9, a cold pressing in the third press unit 42 in a third step 40.
[0060]
　(Third Configuration of the press)
　the third press unit 42, as shown in FIG. 8, and a third upper die 44 and a third lower die 46.
[0061]
　Third lower die 46 is a rectangular convex cross section rectangular, top 46A may have a length and width which can be placed a narrow flat portions 36D of the main body portion 36A of the second molded product 36 there. Cross-sectional shape of the third lower die 46 is not limited to a rectangular shape, have a shape that can be accommodated between the guide surface 44E of the third upper mold 44 to be described later, it may be a trapezoid.
[0062]
　Third upper mold 44 is arranged to face the third lower die 46, a third upper die 44 is connected to a moving device (not shown). Mobile device, for example a hydraulic device is composed of an electric drive apparatus or the like, to move the third upper mold 44 to the pressing direction is upward U or downward D relative to the third lower die 46.
[0063]
　Third upper mold 44, the recess 44A which opens toward the third lower die 46 side is formed in the central portion, the recess 44A includes a guide portion 44B constituting a third lower die 46 side, and a molding portion 44C constituting the rear side of the guide portion 44B.
[0064]
　Molding portion 44C of the concave portion 44A is formed in a rectangular cross section, having the same opening width as the inner side of the opening width of the guide portion 44B.
[0065]
　Guide portion 44B of the recess 44A, the opening width is narrowed in accordance with a third lower die 46 side toward the far side is an upper U side. The guide portion 44B opening width at the lower end face 44D of the third upper mold 44, the other standing portion from the outer surface of the bent portion 36J between one upright portion 36F and the flange portion 36G of the second molded product 36 36F and wider than the width of the to the outer surface of the bent portion 36J between the flange portion 36G.
[0066]
　The inner surface of the guide portion 44B of the recess 44A of the third upper mold 44 is provided with a guide surface 44E which is inclined to the mold center C according to the lower D of the third lower die 46 side upwardly directed U is the back side there. The inner surface of the molding portion 44C of the recessed portion 44A is provided with an extension forming part wall 44F to the pressing direction is upward U or downward D toward the back side from the guide surface 44E. In addition, the inner surface of the molding portion 44C is provided with a molded corner 44G curved surface provided on the end of each molding wall surface 44F constitute, a molding bottom face 44H of continuously arranged both molded corner 44G .
[0067]
　The molded part bottom face 44H and is parallel to the top surface 46A of the third lower die 46, it is perpendicular to the molding bottom face 44H and the shaped wall surface 44F. Thus, as shown in FIG. 9, the third upper mold as the top surface 46A of the third lower die 46 is located at the boundary between the molding portion 44C and the guide portion 44B of the third upper die 44 44 in the bottom dead point to move the, enclosed space and the third upper mold 44 and the third lower die 46 is a rectangular shape.
[0068]
Further, the sectional shape in the cross section of the hardened as described below member 10 (see FIG. 14), the upper surface 48I is an example of a surface included the flange portion 48H is to be slightly narrower trapezoidal than the lower surface 48D it can. In this case, not perpendicular to the molding bottom face 44H and the shaped wall surface 44F, in accordance with the sectional shape of the hardening member 10, slightly narrowed in accordance with intervals between the molding wall surface 44F comes close to the molding bottom face 44H. Thus, the angle formed between the molding wall surface 44F and the molded part bottom face 44H becomes obtuse.
[0069]
　(Third third step by a press device)
　when molded in the third press unit 42, a narrow flat portions 36D of the main body portion 36A of the second molded product 36 to the top surface 46A of the third lower die 46 It is placed and set, as shown in FIG. 8, a third upper mold 44 descends in the mobile device.
[0070]
　Then, while the bent portion 36J between upright portion 36F and the flange portion 36G of the second molded product 36, a bent portion 36J between the other standing portion 36F and the flange portion 36G is the concave portion 44A of the third upper mold 44 It abuts against the guide surface 44E in. In this state, when continuing the downward movement of the third upper mold 44, and one bent portion 36J and the other bent portion 36J of the second molded product 36 is guided by the corresponding guide surface 44E. Thus, upright standing portion 36F is caused to erect portion 36F side facing the narrow flat portion 36D.
[0071]
　When the one of the bent portion 36J and the other bent portion 36J of the second molded product 36 reaches the end of the guide surface 44E, edge EG and the other flange of one flange portion 36G of the second molded product 36 and the edge EG parts 36G are close to each other.
[0072]
　In this state, when continuing the downward movement of the third upper mold 44, as shown in FIG. 9, a third lower die 46 the flange portions 36G abuts on the molding bottom face 44H of the third upper mold 44 tilted to the side. Then, the bent portion between the flange portion 36G and the standing part 36F 36J (see FIG. 8), bent along the forming angle portion of the third upper mold 44 44G. Thus, the edge EG of each flange portion 36G is matched, in the space of the third upper mold 44 and the molding portion 44C which is surrounded by a third lower die 46, the main body portion 36A is rectangular sectional shape .
[0073]
　At this time, the flange portion 36G, as shown in FIG. 4, corrugations 26 are formed at intervals in the longitudinal direction NH, each corrugation 26, the flange 36G (FIG. 4 It is composed of a bent portion 26A which is curved in the thickness direction of the 24G). Then, a corrugated composed of a curved portion 26A of the one flange portion 36G (in FIG. 4 24G), and the other flange portion 36G bend configured corrugated in 26A of (in FIG. 4 24G), the corrugated phase is formed to be shifted a half period in the length direction.
[0074]
　Therefore, one flange portion 36G intersection KB where the corrugated portion 26 formed on (FIG. 4, 24G) which is formed in corrugated portion 26 and the other flange portion 36G (in FIG. 4 24G) crossing ( in reference to FIG. 16), one edge EG and the other edge EG may abut. This prevents collapse of the inner standing portion 36F.
[0075]
　Here, "one of the edges EG and other edge EG may contact" does not indicate a state in which one of the edges EG and the other edge EG is in contact always. During molding, it includes a case where the one of the edge EG and other edge EG in the standing part 36F and the like receives an external force collapses the standing part 36F side facing abuts.
[0076]
　(Intermediate molded article)
　10 is a diagram showing an intermediate molded article 48 molded using the third press unit 42 in the third step 40.
[0077]
　The main body portion 48A of the intermediate molded article 48 has a flat lower surface 48D contiguous with the first supporting portion 48B and the second support portion 48C, and a lower ridge 48E formed on the side edges of the lower surface 48D, raised from the lower ridge line 48E and a side 48F was.
[0078]
　The main body portion 48A of the intermediate molded article 48 has an upper surface 48I is formed by a pair of flange portions 48H that is continuously provided through the upper ridge 48G on each side 48F. This is the widthwise center of the upper surface 48I, butted portion 50 edge EG of the flange portion 48H is butted is formed along the length NH. Thus, the two edge EG of the steel plate 12 are matched in the same sides of the rectangular cross-sectional shape.
[0079]
　Here, the "butt portion 50 which edge EG is butted flange portion 48H", the rectangular cross-sectional shape main body portion 48A of the intermediate molded article 48 is formed, edge EG between the steel sheet 12 in the same edge It shows a portion facing adjacently. In the butted portion 50, edge EG between opposed adjacent are spaced apart. Butt portion 50, a portion of length direction, opposing edges EG themselves may be partial contact.
[0080]
　As described above, molded part bottom face 44H and a not orthogonal each forming wall surface 44F, if the interval between the molding wall surface 44F is somewhat narrower gets closer to the molding bottom face 44H, the body portion 48A of the molded article 48 the cross-sectional shape becomes a trapezoid shape. Here, the rectangular cross-section is also intended to include such a trapezoid shape.
[0081]
　The trapezoidal shaped body portion 48, forming a hardened member 10 shown in FIG. 13 through the fourth step (heating step) and the fifth step to be described later (quenching step). In this quenching member 10, outside the bending top 48I contained the flange portion 48H, if the bending moment in a direction in which the inner bending the lower surface 48D is applied, the longitudinal direction of the putting member 10 stamped on the flange portion 48H tension is generated by the. Moreover, tension in the width direction orthogonal to the longitudinal direction of the quenching member 10 of the flange portion 48H is generated.
[0082]
　At the same time compressive forces in the longitudinal direction is generated in the hardened member 10 to the lower surface 48D, the compression force in the width direction orthogonal to the longitudinal direction of the quenching member 10 of the lower surface 48D is generated. The width direction of the compressive force of the tension and the lower surface 48D in the width direction of the flange portion 48H acts to fall down in the direction of the side surface 48F is brought close to each other flange portion 48H. However, the flange portion 48H is formed with a configured wave-shaped portion 26 at the bent portion 26A which is curved in the thickness direction, and the bent portion 26A of the one flange portion 48H, the bend 26A of the other flange portion 48H because corrugated phase is formed to be shifted a half period in the longitudinal direction, and one edge EG and other edge EG of the two flange portions 48H that face abuts prevent collapsing of side 48F can do. Therefore, quenching member 10 by the bending moment can be prevented bent locally buckled.
[0083]
　Therefore the side 48F collapsing more aggressive induction direction toward to each other flange portion 48H, the angle (angle of the cross section of the lower ridge 48E) formed by the lower surface 48D and side surfaces 48F slightly may be acute.
[0084]
　When the angle between the lower surface 48D and side surfaces 48F too small, the width of the flange portion 48H is narrowed. As a result, strength of the molded article 48 (hardened member 10) is reduced. Thus it is not preferable to the angle formed by the lower surface 48D and side surfaces 48F too small. Angle between the lower surface 48D and side 48F is preferably more than 80 degrees 90 degrees or less.
[0085]
　In the present embodiment, the angle between the lower surface 48D and the side surface 48F of the main body portion 48A is a substantially 90 degrees, the angle between the upper surface 48I and side 48F, a case is approximately 90 degrees as an example explain. Further, the lower surface 48D and the upper surface 48I, as well as a substantially parallel, side surfaces 48F also is substantially parallel to, the main body portion 48A has a rectangular cross-sectional shape.
[0086]
　In the present embodiment, the angle between the lower surface 48D and the side surfaces 48F which is an example of a facing surface of the main body portion 48A, although the case of about 90 degrees will be described as an example, but is not limited thereto . The lower surface 48D and an angle and forms each side 48F may not more than 100 degrees 80 degrees.
[0087]

　In the fourth step, which is an example of a heating step, the intermediate molded article 48 molded in the third step 40, heating above Ac3 transformation point of the steel plate 12 in a heating furnace not shown.
[0088]
　The heating furnace, and a gas heating furnace, or an electric heating furnace, and electric heating furnace, or an infrared heating furnace, high-frequency heating furnace and the like.
[0089]
　Ac3 transformation point showing the austenitizing transformation temperature is the temperature at which the steel plate 12 made of a steel material described above is austenitized, represented by the following formula as an example.
[0090]
　Ac3 (℃) = 910-203 × √C (mass%) + 44.7 × Si (mass%) - 30 × Mn (mass%) - 11 × Cr (mass%) + 700 × S (mass%) + 400 × Al (mass%) + 50 × Ti (% by mass)
[0091]

　The intermediate molded article 48 which has been heated to the Ac3 transformation point or higher in the fourth step, as shown in FIGS. 11 and 12, in a fifth step 52, which is an example of a tempering process to hot press at a hot press device 54.
[0092]
(Hot structure of the press)
　hot press device 54, as shown in FIG. 11, and a hot pressing the upper die 56 and the hot press under die 58.
[0093]
　The hot pressing under die 58, the opened groove 58A upward U is formed. The groove 58A is sized to accommodate the body portion 48A of the intermediate molded article 48, the groove 58A, the central portion in the length direction NH is recessed downward D. Also, the groove 58A has a portion curved portion so as to protrude upward U.
[0094]
　The one side of the length direction of NH hot pressing under die 58, the first formed in the supporting portion 48B are round holes 48J (see FIG. 10) to be inserted for the first positioning pin 58B of the intermediate molded article 48 There has been erected. The first positioning pin 58B prevents rolling of the intermediate molded article 48. On the other side of the longitudinal NH hot pressing under die 58, the second positioning pin 58C can be inserted into the long hole 48K formed in the second support portion 48C of the intermediate molded article 48 (see FIG. 10) It is erected. Second positioning pin 58C, while absorbing the molding errors of the intermediate molded article 48, to prevent rolling of the intermediate molded article 48.
[0095]
　Hot pressing the upper die 56 is disposed to face the hot pressing under die 58, hot pressing upper die 56 is connected to the moving device (not shown). Mobile device, for example a hydraulic device is composed of an electric drive apparatus or the like, to move the hot pressing upper die 56 against the hot press under die 58 to the press direction is upward U or downward D.
[0096]
　Hot pressing the upper die 56 corresponds to the groove 58A of the hot pressing under die 58, the middle portion in the longitudinal direction NH is formed ridge 56A which is curved toward the hot pressing under die 58 there. The ridges 56A of the heat-pressing the upper die 56 and inserted into the groove 58A of the hot press under die 58, a state in which hot pressing upper die 56 reaches the bottom dead center. Then, as shown in FIG. 12, the main body portion 48A of the intermediate molded article 48 in the groove 58A, as well as the lower surface 48D are in surface contact with the groove bottom surface 58D, the upper surface 48I of hot pressing the upper die 56 projections 56A in surface contact with the lower surface 56B. At this time, the side surface 48F of the intermediate molded article 48 is in surface contact with the groove wall surface 58E (see FIG. 11) of the groove 58A.
[0097]
　Thus, Ac3 rapidly deprive the intermediate product 48 of the heat which has been heated above the transformation point with hot press upper die 56 and the hot press under die 58, quenching with the intermediate molded article 48 is cooled (Martensite to site transformation) to.
[0098]
　Further, bent portions 26A formed in the flange portion 48H of the intermediate molded article 48 is curved so as to protrude inward. Therefore, bend 26A is compared with the case where curved so as to protrude outwardly, and the like without the uneven portion of the lower surface 56B of the hot pressing upper die 56 corresponding to the bent portion 26A, the hot press shape of the mold 56 can be simplified.
[0099]
(Fifth step by hot press device)
　when molding in the hot press device 54, as shown in FIG. 11, the upper surface 48I having a butt portion 50 as hot press upper die 56 side the intermediate molded article 48 disposed, inserted through the first positioning pin 58B to the round hole 48J of the first support portion 48B (see FIG. 10). Also, inserting the second positioning pin 58C to the long hole 48K (see FIG. 10) of the second support portion 48C. This prevents rolling while positioning the intermediate molded article 48. Then, set and support the ends of the intermediate product 48 to the upper end surface of the hot press under die 58.
[0100]
　In this state, hot pressing upper die 56 is lowered in the mobile device, the lower surface 56B of the projections 56A of the hot pressing upper die 56 is brought into contact with the upper surface 48I of the intermediate molded article 48. Then, hot pressing upper die 56 is further lowered, as shown in FIG. 12, inserting the projections 56A of the hot pressing upper die 56 to the groove 58A of the hot press under die 58.
[0101]
　Then, the main body portion 48A of the intermediate molded article 48 is to be curved in the out-of-plane direction top 48I having a butt portion 50 is perpendicular to the upper surface 48I, the lower surface of the ridges 56A of the heat-pressing the upper die 56 curved along the groove bottom surface 58D of 56B and hot press under die 58. Thus, the intermediate molded article 48 has a main body portion 48A is bent curved in the length direction.
[0102]
　At this time, the second positioning pin 58C to position the intermediate molded article 48 is inserted through a long hole 48K of the second support portion 48C. Therefore, the main body portion 48A is moved in the direction towards the groove 58A is allowed.
[0103]
　The intermediate molded article 48, the edge EG of the steel plate 12 constituting the butted portion 50 is not bonded. Therefore, butt surfaces of the moderately edge EG during bending process, by displacing the out-of-plane direction of the upper surface 48I, local buckling is suppressed.
[0104]
　In this case, the intermediate molded article 48 corrugations 26 formed (see e.g. FIG. 4) is set to a large portion of the curvature bending in the length direction NH of the main body portion 48A. Since this makes it possible to facilitate the deformation of the out-of-plane direction of the edge EG of the steel plate 12 constituting the butted portion 50, it is possible to further suppress the local buckling.
[0105]
　Then, in a state where the hot pressing upper die 56 reaches the bottom dead center, the lower surface 48D of the intermediate molded article 48 is in surface contact with the groove bottom surface 58D of the hot pressing under die 58, the upper surface 48I is hot in surface contact with the lower surface 56B of the projections 56A of the pressing upper die 56. Further, each side 48F of the intermediate molded article 48 is in surface contact with the groove wall surface 58E of the hot pressing under die 58.
[0106]
　Thus, the intermediate molded article 48 which is austenitized heated above Ac3 transformation point in the fourth step, rapidly heat is cooled deprived hot pressing upper die 56 and the hot press under die 58, It is hardening (martensite).
[0107]
　At this time, since the delay in the cooling of the outer surface of the body portion 48A of rectangular cross-section to cool the inner surface is started, tilting force is generated toward inward side 48F. However, the flange portion 48H of the top surface 48I, corrugations 26 are formed, with one flange portion corrugations 26 and other corrugated portion 26 of the flange portion 48H of 48H constituting the butted portion 50 intersect at the intersection KB when viewed from the direction TH (see FIG. 16) butt. Therefore, by the edge EG of the one flange portion 48H and the edge EG of the other flange portion 48H abuts, it can be suppressed from leaning in the inner side surface 48F.
[0108]
(Quenching member)
　13 is a diagram showing the quenching member 10 which is molded using a hot press apparatus 54 in the fifth step 52, each component is identical to the intermediate product 48 except that curved or represented by the same reference signs for the same.
[0109]
　The main body portion 48A of the hardening member 10 includes a lower surface 48D contiguous with the first supporting portion 48B and the second support portion 48C, the side surface 48F standing upright from the side edge of the lower surface 48D, the flange portion 48H extending from the side surface 48F It is formed in a rectangular sectional shape by a configured top surface 48I in. Angle between the lower surface 48D and side surfaces 48F, and the angle formed by the side surface 48F and the upper surface 48I is approximately 90 degrees.
[0110]
　Use quenching member 10 as a structural member, outside the bending top 48I contained the flange portion 48H, if the bending moment in a direction in which the lower surface 48D facing inward bending is applied, to control the direction of falling down the side 48F Therefore, the angle formed by the lower surface 48D and side surfaces 48F may be acute than 80 degrees 90 degrees.
[0111]
　On the other hand, quenching member 10, outside the bending top 48I contained the flange portion 48H, even when the bending moment in a direction in which the inner bending the lower surface 48D is applied, bending when moment is small aspect 48F collapse is insignificant. In this case, there is a case where control of the direction in which falls down the side 48F is unnecessary.
[0112]
　Furthermore, the quenching member 10, when used as a structural member, such as a different load and bending moment, for example, torsional moment acts, there is a case where control of the direction in which falls down the side 48F is unnecessary. In this case, and for controlling the characteristics of the cross-sectional shape (e.g. the second moment), depending on the purpose of avoidance of interference with other parts, the sectional shape of the hardening member 10 of the upper surface 48I including a flange surface 48H width of the lower surface 48D may be narrow trapezoidal slightly greater than the width. In the tempering member 10, the angle formed between the lower surface 48D and the side surface 48F becomes slightly larger obtuse than 90 degrees. When molding the hardening member 10, it is not possible to mold the third step in the mold of Figure 8 and 9, using another mold die shape is different.
[0113]
　When the angle formed between the lower surface 48D and the side surface 48F too large, the width of the lower surface 48D is narrowed. As a result, strength of the molded article 48 (hardened member 10) is reduced. Thus it is not preferable angle of the cross section of the lower ridge 48E too large. Therefore, when the angle between the lower surface 48D and side surfaces 48F and obtuse, the angle formed by the lower surface 48D and side 48F, preferably not more than 100 degrees 90 degrees.
[0114]
　Figure 14 is an enlarged view of a B portion of FIG. 13, the main body portion to the 48A of the upper surface 48I, butted portion corrugations 26 provided at intervals in the extending direction EH of 50 in quenching member 10 prevention structure overlap by is formed.
[0115]
　Corrugations 26, as shown in FIGS. 14 and 15, while a bent portion 26A formed on the edge EG of the steel plate 12 constituting the butted portion 50, bending is formed on the other edge EG It is formed by a section 26A. Further, a bent portion 26A of one of the edge EG, The bent portion 26A of the other edge EG, are arranged at different positions while partially overlapping with the extending direction EH butt portion 50.
[0116]
　Specifically, as shown in FIG. 16, the wave phase in constituted wave portion 26 in the bending portion 26A is shifted by a half period in the extending direction EH butt portion 50. Thus, intersection KB end edge EG that constitute the butted portion 50 intersect as viewed from the direction TH butt is formed by corrugation 26.
[0117]

　In a sixth step which constitutes the final step, the first support portion 48B and the second support portion 48C is separated from the main body portion 48A of the hardening member 10, a final product.
[0118]

　Next, a description will be given of the operation and effects of the present embodiment.
[0119]
　In this manufacturing method of quenching member, an intermediate product 48 of rectangular cross-section edge EG are butt of the steel plate 12, in the heating step of the fourth step, heating above Ac3 transformation point of the steel plate 12. Then, the quenching step of the fifth step 52, quenching with hot pressing upper die 56 and the hot press under die 58 of the hot press device 54. Therefore, as compared with the molded article which is not quenched, high tensile strength material, can be obtained hardened member 10 having high flexural strength as members. The tensile strength of this case, it is also possible to more 1180 MPa.
[0120]
　Further, it is possible to heat a flat steel plate 12 as compared with the case of hot pressing, heat is less likely to escape after heating, to suppress the temperature drop before quenching by the hot press device 54. Thus, the heating process time allowed for starting hot forming can be lengthened after completion, it is possible to reduce the risk of quenching failure occurs due to temperature drop. Therefore, it can be made uniform over the intensity of the quenching member 10 throughout.
[0121]
　Here, in a general hot pressing, the temperature drop of the steel sheet after the heating is likely to be a challenge, if the plate thickness is thin, a case, for example 2.3mm or less, the present embodiment at the time of such conditions it is particularly effective.
[0122]
　Furthermore, the intermediate molded article 48 to be hardened is processed into a rectangular cross-sectional shape. Therefore, a flat steel plate 12 heated as compared to the case of transporting to the pressing device, is deformed during transportation (sag) is suppressed, thereby facilitating the transport task. Here, if the deformation during transport generally heated steel sheet is easy to be a challenge in plate thickness is particularly thin, a case of for example 1.2mm or less, the present embodiment is particularly effective when such conditions it is.
[0123]
　Normally, by raising the heating temperature of the steel plate 12 in the heating furnace, temperature before quenching by the hot press device 54 can be considered a way to be equal to or greater than a predetermined value. However, if the plating material has been subjected to plating processing object, the higher the heating temperature in the heating furnace, alteration of the plating is concerned. For such plating material, manufacturing method of quenching member of this embodiment is effective.
[0124]
　Figure 17 shows the measurement result of measuring the temperature change after the removal of the members of different thickness from the furnace. And temperature change upon Delo was heated to 950 ° C. Each member in a heating furnace is shown in Figure 17.
[0125]
　17, the plate thickness T is the temperature change of the intermediate molded article 48 of the present embodiment in which the steel sheet 0.8mm and rectangular cross-sectional shape, thickness T is the first comparative example 60 flat of 0.8mm It is shown. Further, the thickness T is the third comparative example and the second comparative example 62 comprising a flat GA material 1.6mm (galvannealed steel sheet), the thickness T becomes a flat steel plate 1.6mm temperature change of the 64 are also shown.
[0126]
　Thickness T is in the first comparative example 60 comprised a flat steel plate 0.8 mm, it is found that sudden temperature drops from 1 seconds after Delo. On the other hand, the thickness T is, 0.8 mm in the intermediate molded article 48 of a rectangular cross-sectional shape of the temperature reduction after exiting furnace is gentle. The intermediate molded article 48, the thickness T is, and the second comparative example 62 comprising a flat GA material 1.6mm, thickness T is of the third comparative example 64 comprising a flat steel plate 1.6mm it is substantially the same as the temperature changes.
[0127]
　Intermediate molded article 48 of the present embodiment from the test plate thickness T is found to have a flat Comparative Examples 62 and 64 the same temperature holding capacity of 1.6 mm.
[0128]
　Then, in the quenching step of the fifth step, the bend between the thermoforming the intermediate molded article 48 to be curved in the out-of-plane direction in the extending direction EH upper surface 48I is butted portion 50 having a butt portion 50 baked to put. Thus, it is possible to perform the shaping and bending quenching of the intermediate molded article 48 simultaneously, it is possible to shorten the manufacturing time.
[0129]
　Thus quenching member 10 obtained has a rectangular cross-sectional shape, the ridge line including the lower edge line 48E and the upper ridge 48G longitudinally extending NH exist four. Therefore, as compared with the sectional groove shape ridge line of the longitudinal NH is two, it is possible to increase the flexural rigidity. Thereby, while maintaining the desired bending stiffness, it is possible to reduce the cross-sectional shape of the hardening member 10, the weight can be reduced.
[0130]
　Further, since bending a intermediate molded article 48 which has been heated to Ac3 transformation point or higher in the heating step of the fourth step, as compared to the case of bending by cold forming, facilitating good dimensional accuracy quenching member 10 to be obtained.
[0131]
　Here, generally when the metal sheet to press molding a groove shape, the inner side and outer side of the channel by pressing a mold, pressed into a desired groove shape.
[0132]
　However, in the present embodiment, for pressing only the outer of the intermediate molded article 48 of a rectangular cross-sectional shape in a mold, falling to the inside of the rectangular cross-sectional shape of the side surface 48F is concerned.
[0133]
　In particular, the intermediate molded article 48 which is cooled from the outside at the beginning hot pressing, by hot pressing under die 58 is inclined to the outside of the side surface 48F is suppressed. In this state, when the inside of the cooling of the intermediate molded article 48 begins, because the tilting force inward on the side surfaces 48F acts, leaning in the inner side surface 48F is concerned.
[0134]
　Therefore, in this embodiment, in the intermediate molded article 48 is brought into contact with the edge EG together of the steel plate 12 constituting the butt portion 50 partially. Thus, by the edge EG each other butted portion 50 prior to falling into the inside of the side surface 48F abuts, it can be suppressed from leaning in the inner side surface 48F. Thus, it is possible to suppress their shape of rectangular cross-section.
[0135]
　At this time, the edge EG of the steel plate 12, bent portion 26A which is bent in a rectangular sectional shape is formed, when viewed from the butt direction TH, edge EG each other butt portion 50 intersect intersect parts KB is formed. Therefore, even if the edge EG of the butt portion 50 is shifted to the thickness direction, it is possible to maintain the contact state between the edge EG.
[0136]
　Furthermore, the bending portion 26A is formed respectively on each edge EG of the butt portion 50, a bent portion 26A formed in the bent portion 26A and the other edge EG formed on one edge EG They are arranged at different positions in the extending direction EH of butted portions 50. Thus, the corrugated phase of one edge EG of adjacent bent portion 26A is formed, and the other edge EG wave type phase, and is formed to be shifted a half period in the length direction.
[0137]
　Such can extend the range of contact edges EG each other by the configuration, it is possible to suppress the pass-between edge EG.
[0138]
　Then, the bending portion 26A is formed in a curved shape protruding to the inside of the rectangular cross-sectional shape of the intermediate molded article 48. Therefore, bend 26A can be compared with curved projecting to the outside of the rectangular cross-section, it is brought into close contact with portion which becomes the upper surface 48I of the bending portion 26A is formed with a reinforcing target.
[0139]
　Further, the bending portion 26A is formed at the time of cold pressing in a first step 14 which is an example of a molding process. Therefore, it is possible to perform the molding of the molding and bending portion 26A of the flange portion 24G at the same time.
[0140]
　Then, the intermediate product 48 of rectangular cross-section, shaped by hot pressing upper die 56 and the hot press under die 58 for pressing from the outside. Accordingly, or using the core to be inserted inside the intermediate molded article 48, and the standing portion 36F of the second molded product 36 as compared with the case of or using a movable die for pressing from the side, simple mold structure it is possible to achieve the reduction.
[0141]
　In the present embodiment has described the case of forming a curved bend 26A to each edge EG of the butt portion 50, bent portion 26A is not limited to this shape, the following embodiments it may be of the form.
[0142]
　(Second Embodiment)
　FIG. 18 is a diagram showing a second embodiment, for the first embodiment and the same or similar parts, with a description thereof will be omitted with denoted by the same reference numerals and their descriptions are omitted .
[0143]
　Figure 18 is a view corresponding to a part perspective view seen from D in Fig. 15 of the first embodiment. The intermediate molded article 48 and hardened member 10 according to this embodiment, bent portions 26A formed on the edge EG of the steel plate 12 constituting the butted portion 50, V-shaped projecting inwardly of the rectangular cross-section It is formed in. Thus, corrugations 26 configured in adjacent bend 26A is formed in a polygonal line when viewed from the direction TH butt.
[0144]
　Even with such a configuration, it is possible to obtain the same effect as the first embodiment.
[0145]
　In the present embodiment, although the bending portion 26A formed on the edge EG of the steel plate 12 has been described which projects inwardly of the rectangular cross-sectional shape is not limited thereto, the following embodiments it may be.
[0146]
(Third Embodiment)
　FIG. 19 is a diagram showing a third embodiment, the same or similar parts in the first embodiment, the description thereof will be omitted with denoted by the same reference numerals and their descriptions are omitted .
[0147]
　Figure 19 is a view corresponding to a part perspective view seen from D in Fig. 15 of the first embodiment. The intermediate molded article 48 and hardened member 10 according to this embodiment, bent portions 26A formed on the edge EG of the steel plate 12 constituting the abutting portion 50 projects inside and outside the rectangular cross-sectional shape.
[0148]
　Even with such a configuration, it is possible to obtain the same effect as the first embodiment.
[0149]
　In the present embodiment has described the case of forming the bent portion 26A in the opposite edges EG of the steel plate 12 constituting the butted portion 50 is not limited thereto, as the following embodiments it may be.
[0150]
(Fourth Embodiment)
　FIG. 20 is a diagram showing a fourth embodiment, the same or similar parts in the first embodiment, the description thereof will be omitted with denoted by the same reference numerals and their descriptions are omitted .
[0151]
　Figure 20 is a view corresponding to a part perspective view seen from D in Fig. 15 of the first embodiment. In the intermediate molded article 48 and hardened member 10 according to the present embodiment, without being bent portion 26A is formed on one edge EG of the steel plate 12 constituting the butted portion 50, bends only in the other end edge EG portion 26A is formed.
[0152]
　Even with such a configuration, it is possible to obtain the same effect as the first embodiment.
[0153]
　In each embodiment, although a plurality of intersections KB the butt portion 50, the cross section KB may be one.
[0154]
　It is a description of the code below.
[0155]
10 Hardening member
12 steel
26 Corrugated portion
26A bent portion
48 intermediate product
48A body portion
48D bottom surface (opposing
surface) 48I top (one
surface) 50 abutting portion
52 fifth step
54 the hot press device
56 hot press upper type
58 hot pressing under die
EG edge
KB intersection
TH butt direction
[0156]
　«Supplementary Note»
　from the specification, the following aspects are conceptualized.
[0157]
　In other words, embodiments 1
　and heating the intermediate molded article which is processed into a rectangular cross-sectional shape having a butted portion where the two edges of the steel sheet was butted in the same side than Ac3 transformation point of the steel sheet,
　and that the heated said intermediate molded article quenched in the mold,
　the production method of quenching member having a.
[0158]
　Embodiment 2,
　in the quenching, aspects one surface having the butted portion, and the intermediate molded article to be curved in the out-of-plane direction in the extending direction of the butted portion hardened by forming bent hot method for producing a hardened member according to 1.
[0159]
　Embodiment 3,
　butted manufacturing method of quenching member according to embodiment 1 or embodiment 2 edges of the steel plate are in contact.
[0160]
　Embodiment 4,
　the steel sheet further comprises that molding the intermediate molded article,
　said intermediate molded article is caused to face at least one edge is in the butted portion, bent into partially thickness direction quenching method for producing a member as set forth in aspect 1, there is a bend to any of embodiments 3.
[0161]
　Embodiment 5,
　the ratio of the height of the curved direction of the hardening member against a plate thickness of the steel plate in the transverse plane, the manufacturing method of quenching member according to any of embodiments 4 from embodiment 1 is 40 or less.
[0162]
　Embodiment 6,
　the plate thickness of the steel plate, the manufacturing method of quenching member according to any of embodiments 5 from embodiment 1 is 2.3mm or less.
[0163]
　Embodiment 7,
　a rectangular cross-sectional shape in which the end edges between the steel faces adjacent in the same edge, the one face which edges face each other is curved in the out-of-plane direction in the extending direction of the edge, and quenching member having a cross-section of the edge with each other said end edges to each other when viewed from the opposing direction opposite crossing.
[0164]
　Embodiment 8,
　at least one of the edges, there is bend curved to one side in the thickness direction, quenching member embodiments 7, wherein there is the intersection inside the bent portion.
[0165]
　Embodiment 9,
　wherein the bent portion is hardened member aspect 8, wherein the curved inside of the rectangular cross-sectional shape.
[0166]
　Embodiment 10,
　there is the bent portion to respective opposite end edges, different positions and bend formed on one edge facing the other are formed on the edge was bent portion in the extending direction of the edge quenching member according to embodiment 8 or embodiment 9 in.
[0167]
　Embodiment 11,
　the ratio of the bending direction of the height of the hardening member against a plate thickness of the steel plate in the transverse plane, quenching member according to any of embodiments 10 from embodiment 7 is 40 or less.
[0168]
　A twelfth aspect is
　a plate thickness of the steel sheet, quenching member according to any of embodiments 11 from embodiment 7 is 2.3mm or less.
[0169]
　Thirteenth aspect, the angle of the facing surface that faces the one surface, and a side surface connecting said opposing surface and said one surface formed is hardened according to any of embodiments 12 from embodiment 7 or less 100 degrees 80 degrees Element.
[0170]
　
　In addition, the present specification, the following other aspects are conceptualized.
[0171]
　That is, other embodiments 1,
　heating to heat the intermediate molded article which is processed into a rectangular cross-sectional shape having a butted portion where the two edges of the steel sheet was butted in the same side than Ac3 transformation point of the steel sheet step and,
　the quenching step, which said intermediate molded article is heated at said heating step quenching in a mold
　manufacturing method of quenching member having a.
[0172]
　Other embodiments 2,
　wherein the quenching step, a surface having the butted portion, the intermediate molded article to be curved in the out-of-plane direction in the extending direction of the butted portion by molding bent hot baked quenching method for producing a member according to another embodiment 1 to be put.
[0173]
　Other embodiments 3,
　butted manufacturing method of quenching member according to embodiment 1 or other embodiments 2 other edge is in contact of the steel sheet.
[0174]
　Other aspects 4,
　comprises a forming step of forming the steel sheet into the intermediate molded article,
　the molding step, butted at least one edge is in the butted portion, bent into partially thickness direction method for producing a hardened member according to any bend from another aspect 1 which form other aspects 3.
[0175]
　Other aspects 5,
　the ratio of the bending direction of the height of the hardening member against a plate thickness of the steel plate, producing quenching member according the other embodiment 1 is 40 or less in any of the other aspects 4 Method.
[0176]
　Other aspects 6,
　the plate thickness of the steel sheet, quenching method for producing a member according the other embodiment 1 is 2.3mm or less in any of the other aspects 5.
[0177]
　Other embodiments 7,
　is a rectangular cross-section having a butt portion edge of the steel sheet is abutted on one side, one side said is curved in the extending direction of the butted portion in the out-of-plane direction, the butt quenching member having a cross-section of the edge between the part intersect as viewed from the butt direction.
[0178]
　Other aspects 8,
　at least one edge of the butted portion, portions bent curved to one side in the thickness direction is formed, hardened member of another embodiment 7, wherein said intersecting portion is formed .
[0179]
　Other aspects 9,
　wherein the bent portion, the rectangular cross-section quenching member of another embodiment 8, wherein the curved is formed on the inside of the shape.
[0180]
　Other embodiments 10,
　wherein the bent portions are formed respectively on each edge constituting the butted portion, and a bent portion formed at one end edge opposite the other are formed on the edge was bent portion is the quenching member according to another aspect 8 or other aspects 9 are arranged at different positions in the extending direction of the butt portion.
[0181]
　Other embodiments 11,
　the ratio of the bending direction of the height of the hardening member against a plate thickness of the steel sheet, quenching member as set forth in another aspect 7 is 40 or less in any of the other aspects 10.
[0182]
　Other twelfth aspect,
　the thickness of the steel sheet, quenching member according to any of the other aspects 11 from another aspect 7 is 2.3mm or less.
[0183]
　In these other embodiments the following advantages can be obtained.
[0184]
　According to another aspect 1, after heating the intermediate product in which the end edges of the steel sheet is processed into a rectangular cross-sectional shape is butted than Ac3 transformation point, since quenching in a mold while hot forming, high strength, and a longitudinal bending dimensional accuracy good quenching member shape, even if a small thickness, can be molded without buckling or wrinkles.
[0185]
　Furthermore, the intermediate molded article to be hardened is processed in a substantially closed cross section. Therefore, as compared with the case of hot forming by heating the flat steel plate, the intermediate molded article is unlikely to heat escapes after heating, since the temperature decrease is suppressed, from after the heating step is completed to start hot forming it is possible to take a long time.
[0186]
　Thus, it is possible to reduce the risk of quenching failure due to temperature drop takes place, can have high robustness manufacturing process.
[0187]
　According to the manufacturing method of quenching member of the other aspects, the high strength hollow-rectangular cross-section member which is curved in the longitudinal direction can be obtained with good dimensional accuracy, to further suppress hardening failure due to temperature drop can.
[0188]
　2017 March 15 discloses a the Japanese Patent Application No. 2017-049911 filed on days, entirely incorporated herein by reference.
[0189]
　Further, all documents described herein, patent applications and technical standards, each individual publication, to the same extent as if the patent and technical standards are incorporated by reference marked specifically and individually, It incorporated by reference herein.

The scope of the claims
[Requested item 1]
　And that the two edges of the steel sheet to heat the intermediate molded article which is processed into a rectangular cross-sectional shape having a butted portion is butted in the same side than Ac3 transformation point of the steel sheet,
　heating the said intermediate molded article and that quenching in a mold,
　hardening method for producing a member having a.
[Requested item 2]
　In the quenching, a surface having the butted portion, wherein said intermediate molded article to be curved in the out-of-plane direction in the extending direction of the butted portions in claim 1, quenching by molding bent hot the method of manufacturing quenching member.
[Requested item 3]
　Butted manufacturing method of quenching member according to claim 1 or claim 2 edges of the steel plate are in contact.
[Requested item 4]
　Further comprising molding the said steel plate to said intermediate molded article,
　said intermediate molded article, the butt butted least one edge is at the portion partially is bent portion bent toward the plate thickness direction method for producing a hardened member according to claim 1, claim 3.
[Requested item 5]
　The ratio of the height of the bending direction of the hardening member against a plate thickness of the steel plate in the transverse plane, the manufacturing method of quenching member according to any one of claims 1 to 4 is 40 or less.
[Requested item 6]
　A plate thickness of the steel plate, the manufacturing method of quenching member as claimed in any one of claims 5 is 2.3mm or less.
[Requested item 7]
　A rectangular cross-sectional shape in which the end edges between the steel faces adjacent in the same edge, the one face which edges face each other is curved in the out-of-plane direction in the extending direction of the edge, and said end edges to each other quenching member having a cross-section but intersect the end edges to each other when viewed from the opposing direction facing.
[Requested item 8]
　At least one of the edges, there is bend curved to one side in the thickness direction, the bent portion hardened member according to claim 7, wherein the intersection is in the.
[Requested item 9]
　The bent portion is hardened member curved to have claim 8, wherein the inner side of the rectangular cross-sectional shape.
[Requested item 10]
　There is a bend in the respective opposite end edges, and a curved portion formed on one edge facing the other are formed on the edge was bent portion is in a different position in the extending direction of the edge claim 8 or quenching member according to claim 9.
[Requested item 11]
　Quenching member according to any one of the ratio of the bending direction of the height of the hardening member against a plate thickness of the steel plate in the transverse plane, according to claim 10 claim 7 is 40 or less.
[Requested item 12]
　Quenching member according to claim 11 wherein the plate thickness of the steel sheet, according to claim 7 is 2.3mm or less.
[Requested item 13]
　A facing surface that faces the one surface, the opposite surface and the angle between the side surfaces connecting one aspect, quenching member according to any one of claims 12 to claim 7 or less 100 degrees 80 degrees.