JP2008068282A - Hot press working apparatus and hot press working method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hot press working apparatus and a hot press working method by which a press forming, a cutting work in the state, where the load on cutting tool is satisfactorily reduced, and a quenching can be applied to heated metal plate as a series of stages. <P>SOLUTION: The apparatus of hot press working is provided with a lower die 10 and an upper die 20 which are relatively approachable and separable and trimming edges 5 as a cutting tool provided on the side of the upper die 20. The lower die 10 and the upper die 20 respectively have pressing parts 12, 23 for cutting object parts with the cutting object part of the metal plate or the vicinity with the trimming edges 5 are pinched by cooperation. In the pressing part 12 for the cutting object of the lower die and the pressing part 23 for the cutting object of the upper die, a Peltier module 3 respectively incorporated. Each Peltier module 3 is electrically connected to a direct current power source 7 through a current control circuit 6 for controlling the direction of the current of the direct current which flows through the Peltier module. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a hot press working apparatus and a hot press working method for performing press forming, cutting and quenching as a series of steps on a heated metal plate material.

  In the field of metal processing, hot press processing that simultaneously performs press forming and quenching by heating the steel plate as the starting material to its quenching temperature and pressing the steel plate in a high temperature state with a relatively low temperature mold. The method (hot pressing method) is known. However, in many cases, it is not possible to obtain a metal product of the desired shape by simple hot pressing. Therefore, mechanical cutting such as trimming and drilling is performed on the primary molded product obtained by hot pressing. In general, the final product is obtained. However, the excision processing after press molding was for the primary molded product whose hardness was increased by quenching at the same time as press molding. There was a problem of tending.

  As a measure for solving the problem of shortening the tool life, Patent Literature 1 discloses a hot press working method and apparatus for steel. In the processing apparatus of Patent Document 1, the lower die opposite to the upper die (movable die) is supported by floating with a die cushion so that both the upper and lower die can be moved relatively to each other even after die matching. A machining blade (22) and a trim blade (26) are provided on the side as cutting means. In hot pressing, in the process of pressing the steel material heated to the quenching temperature with the upper and lower molds, drilling and trimming with the machining blade and the trim blade are performed simultaneously, and after the drilling, the upper The die presses the lower die against the repulsive force of the die cushion, and the upper die keeps pressing the lower die at the position where the die cushion is fully contracted, thereby rapidly cooling the steel material, so that Quenched. According to the processing method of Patent Document 1, since the high-temperature steel material sandwiched between the upper and lower molds is drilled and trimmed in a substantially unhardened state before being subjected to full-scale quenching, It is said that it is possible to reduce the burden on the trim blade and prevent the shortening of the life of these cutting tools.

JP 2005-248253 A

  However, even with the hot press working apparatus and method disclosed in Patent Document 1, it seems that it is actually difficult to sufficiently extend the life of cutting tools such as working blades and trim blades. This is because, in the press molding process before full quenching by the upper and lower molds is performed at the position where the die cushion is fully contracted, the entire steel material in a heated state comes into contact with the lower mold and the upper mold at a low temperature. That is, from the point of contact with the mold, the entire steel material is cured by being cooled. Therefore, it is difficult to say that the burden (mechanical load) of the cutting tool that acts on such a steel material is sufficiently reduced.

  An object of the present invention is to provide a hot press working apparatus capable of performing cutting and quenching as a series of processes in a state in which the burden of a press forming and cutting tool is sufficiently reduced on a heated metal plate. It is to provide a hot press working method. In addition to extending the life of the cutting tool, the metal plate material that has been press-molded and cut is subjected to quenching.

  The hot press working apparatus of the present invention includes first and second molds that can be relatively approached and separated, and a cutting tool provided on one side of the first and second molds. A hot press working apparatus for press forming, cutting and quenching the formed metal plate material, wherein the first and second molds are parts to be cut of the metal plate material by the cutting tool or Each has an excision target pressing portion capable of clamping in cooperation with the vicinity thereof, and at least one of the first type excision target pressing portion and the second type excision target pressing portion. Is characterized in that a Peltier module is incorporated. More preferably, the Peltier module is a hot press working apparatus that is electrically connected to a DC power source via a current control circuit that controls the direction of a DC current flowing through the Peltier module.

  The hot press working method of the present invention includes first and second molds that can be relatively approached and separated, and a cutting tool provided on one side of the first and second molds, Each of the first and second molds has a cutting target pressing portion that can be clamped in cooperation with the cutting target portion of the metal plate or the vicinity thereof by the cutting tool. It is a hot pressing method of a metal plate material using a hot pressing device in which a Peltier module is incorporated in at least one of the cutting target pressing portion and the second type cutting target pressing portion. Then, a preheating step for preheating the surface of the pressing portion to be cut in which the Peltier module is incorporated by passing a direct current through the Peltier module, and the heated metal plate material between the first and second molds. And press-molding with these first and second molds, and the first mold to be cut and the second mold to be cut are pressed by the first mold and the second mold to be cut when pressed. A cutting step of cutting the portion to be cut of the metal plate material with the cutting tool substantially synchronously with the press forming, and a direct current flowing through the Peltier module simultaneously with or immediately after the cutting. By reversing the direction of the current and cooling the surface of the excision target pressing part in which the Peltier module is incorporated, the surface of the excision target pressing part is cooled by turning from heating to cooling. A hot pressing method, wherein the sequentially executing a local quenching step of performing quenching to be resected or near the site of the metal plate material.

[Action]
The point of the present invention is that a Peltier module is incorporated in a hot press working apparatus. In the Peltier module, one of the front and back surfaces of the module is heated and the other is cooled according to the direction of the direct current flowing therethrough. By utilizing the characteristics of the Peltier module, the temperature of each surface of the first type excision target pressing part and / or the second type excision target pressing part in which the Peltier module is incorporated is heated or cooled. Thus, the state of the metal structure at or near the excision target portion of the metal plate that is in contact with the surface of the excision target pressing portion can be controlled.

  The hot press working method of the present invention is carried out using the hot press working apparatus of the present invention. First, the surface of the excision object pressing portion in which the Peltier module is incorporated is preheated by applying a direct current to the Peltier module of the hot press working apparatus (preheating step). Then, in the first mold and / or the second mold, the surface of the excision target pressing part in which the Peltier module is incorporated is in a heated state, and the surface other than the excision target pressing part is in an unheated state (that is, relatively (Low temperature). Next, the heated metal plate material is disposed between the first and second molds, and press-molded with these first and second molds (press molding process). Then, the metal plate material is press-molded into a shape corresponding to the shape of both molds by the shaping action of the first and second molds. However, at or near the excision target part of the metal plate pressed by the excision target pressing part preheated by the Peltier module, there is no noticeable temperature drop and no immediate baking, whereas the excision target press in the non-heated state The remainder of the metal plate material pressed by the mold part other than the part is baked based on a large temperature difference between the metal plate material and the mold.

  By using the cutting tool almost synchronously with the press molding for the cutting target portion of the metal plate material sandwiched between the first mold cutting target pressing portion and the second mold cutting target pressing portion during the press molding. Excision processing is performed (excision processing step). At this stage, as described above, the portion to be cut of the metal plate or the vicinity thereof is not hardened and is not hardened, so that the cutting with the cutting tool is performed very smoothly. Therefore, the burden on the cutting tool is light and blade spills are less likely to occur. Further, at the same time as or immediately after the excision process, the direction of the direct current flowing through the Peltier module is reversed, and the surface of the excision target pressing portion in which the Peltier module is incorporated is changed from heating to cooling (local quenching). Process). Then, quenching is performed also on the portion to be cut of the metal plate material in contact with the pressing portion to be cut or the vicinity thereof.

  As described above, according to the hot press working method of the present invention, the portion of the metal plate material pressed by the mold portion other than the cutting target pressing portion in which the Peltier module is not incorporated is subjected to quenching simultaneously with press molding. On the other hand, at or near the cutting target portion of the metal plate pressed by the cutting target pressing portion in which the Peltier module is incorporated, quenching is not performed at the press molding stage, and at the same time as cutting processing by the cutting tool or Immediately after that, quenching is performed by reversing the direction of the direct current flowing through the Peltier module. Accordingly, the entire metal plate material that has been subjected to press forming and cutting processing is uniformly quenched.

  According to the hot press working apparatus and the hot press working method of the present invention, a series of steps of cutting and quenching in a state in which the burden of the cutting tool is sufficiently reduced on the heated metal plate material. Can be applied as In addition, the life of the cutting tool can be extended, and the entire metal plate material subjected to the press molding and cutting can be uniformly quenched.

  An embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 1, the hot press working apparatus of this embodiment includes a lower mold base 1 that is a fixed base, and an upper mold base 2 disposed above the lower mold base 1. The upper mold base 2 is supported by a support drive mechanism (not shown) so as to be movable in the vertical direction (up and down direction). As a result, the upper mold base 2 can be approached and separated from the lower mold base 1.

  On the lower mold base 1, a lower mold 10 as a first mold or a fixed mold is fixedly installed. The lower mold 10 includes a central convex portion 11 that swells upward and two die portions 12 that are disposed on the left and right sides of the central convex portion 11. It has a cross-sectional shape. The left and right die portions 12 form a part of the lower mold 10, and each die portion 12 is formed with a horizontal upper surface 12a and a vertical side surface 12b.

  The horizontal upper surface 12a of each die portion is a pressing surface for shaping that is involved in press forming of the metal plate material M by pressing the metal plate material M as a work (work object) together with the central convex portion 11 during press forming. is there. On the other hand, the vertical side surface 12b of each die part functions as a fixed side blade surface involved in trim processing of the left and right end portions of the metal plate M in cooperation with an upper die side trim blade 5 described later. A Peltier module 3 is incorporated in each of the left and right die parts 12. The Peltier module 3 incorporated in each die part 12 heats or cools the upper surface 12a (pressing surface) of each die part 12 based on external power feeding control.

  On the lower side of the upper mold base 2, an upper mold 20 as a second mold or a movable mold is connected and supported via a spring 4 so as to be slightly movable relative to the upper mold base 2 in the vertical direction. As shown in FIGS. 2 and 3, the upper mold 20 includes an upper mold main body 21 and left and right nesting portions 23 that are integrally attached to the left and right sides of the lower surface of the upper mold main body 21. More specifically, the upper mold 20 includes an upper mold main body 21 having a central concave portion 22 opened on the lower surface side, and two nesting portions 23 arranged on the left and right sides of the central concave portion 22. It has a concave cross-sectional shape as a whole. The left and right nesting portions 23 form part of the upper mold 20, and a horizontal lower surface 23 a and a vertical side surface 23 b are formed in each nesting portion 23.

  The horizontal lower surface 23a of each nesting part is a pressing surface for shaping that presses the metal plate material M as a workpiece together with the upper die body 21 during press forming and participates in the press forming of the metal plate material M. On the other hand, the vertical side surface 23b of each nesting portion is continuous with the left and right vertical side surfaces 21a of the upper die main body 21, thereby providing a sliding guide surface for the trim blade 5 described later. A Peltier module 3 is incorporated in each of the left and right nesting portions 23. The Peltier module 3 incorporated in each nesting part 23 heats or cools the lower surface 23a (pressing surface) of each nesting part 23 based on external power feeding control.

  As shown in FIG. 1, a pair of left and right trim blades 5 as a cutting tool is further provided below the upper mold base 2. Since both the trim blades 5 are fixed to the upper mold base 2, the trim blade 5 can approach and separate from the lower mold base 1 and the lower mold 10 together with the upper mold base 2 and the upper mold 20. However, when the upper mold main body 21 is displaced relative to the upper mold base 2 in accordance with the expansion and contraction of the spring 4, both the trim blades 5 are provided on the left and right side surfaces 21a of the upper mold main body and the respective side surfaces of the left and right nesting portions. Relative movement in the vertical direction along 23b.

  According to this hot press working apparatus, when the lower mold 10 and the upper mold 20 are joined or closest, the upper mold central concave portion 22 is fitted to the lower mold central convex portion 11, and the lower mold The lower surfaces 23a of the left and right nesting portions of the upper mold 20 can come into contact with the upper surfaces 12a of the left and right die portions 10 respectively. Further, both the upper and lower trim blades 5 are sandwiched between the lower die portion upper surface 12a and the upper mold nesting portion lower surface 23a, and the left and right end portions of the metal plate M held between the two portions 12 and 23. This is a cutting tool for performing trim processing (specifically, vertical cutting) along the side surface 12b of the die portion with respect to (the part to be cut). Therefore, the lower die part 12 and the upper mold nesting part 23 in this embodiment are “a cutting target pressing part that can be clamped in cooperation with the cutting target part of the metal plate M or its vicinity by the cutting tool”. Is positioned.

  As shown in FIG. 1, a total of four Peltier modules 3 incorporated in the lower mold 10 and the upper mold 20 are connected to a DC power supply 7 via a current control circuit 6 that controls the direction of the DC current flowing through each Peltier module 3. Electrically connected. Here, the Peltier module will be briefly described. The Peltier module 3 is composed of a thermoelectric cooling element 30 composed of a junction pair of a P-type semiconductor and an N-type semiconductor as shown in FIG. 5, and a plurality of thermoelectric cooling elements 30 are electrically connected as shown in FIG. A unit that is connected in series. In the thermoelectric cooling element 30 constituting the Peltier module 3, one of the upper surface 31 and the lower surface 32 of the element is heated and the other is cooled by passing a direct current in a specific direction, and the other is cooled. By reversing the direction of the current, the heating / cooling relationship on the upper and lower surfaces 31, 32 of the element is switched. Incidentally, when the direction of the direct current flow is the direction shown in FIGS. 4 and 5, the upper surface 31 of the thermoelectric cooling element is a cooling surface (heat absorption surface), and the lower surface 32 is a heating surface (heat radiation surface). When the two switches 33 and 34 are simultaneously switched in the circuit diagram of FIG. 5, the direction of the direct current flow is reversed, the upper surface 31 of the thermoelectric cooling element becomes a heating surface (heat dissipation surface), and the lower surface 32 becomes a cooling surface (heat absorption surface). ) In FIG. 5, a circuit (a circuit including the two switches 33 and 34) interposed between the thermoelectric cooling element 30 and the battery 35 (DC power supply) controls the direction of the DC current flowing through the Peltier module 3. An example of the current control circuit 6 is shown.

  Next, the hot press processing method of the metal plate material M using the hot press processing apparatus of this embodiment is demonstrated, referring FIG.1, FIG.6 and FIG.7.

  Prior to the start of hot pressing, as shown in FIG. 1, the upper mold base 2, the trim blade 5, and the upper mold 10 are kept on standby in a state where the upper mold 20 is separated from the lower mold 10. During this standby time, a direct current is supplied from the direct current power supply 7 to the respective Peltier modules 3 of the lower mold 10 and the upper mold 20 via the current control circuit 6. By passing a direct current through each Peltier module 3, the upper surface 12a of the lower left and right die portions and the lower surface 23a of the upper left and right nested portions are heated, and the surface temperature of these upper surface 12a and lower surface 23a is about 600 to 700 ° C. Let the temperature rise. The central portions of the lower die 10 and the upper die 20 are in a non-heated state except for the lower left and right die portions 12 and the upper left and right nested portions 23 in which the Peltier module 3 is incorporated. The temperature is kept approximately at room temperature (for example, around 30 ° C.).

  Next, the metal plate M as a workpiece is heated to a quenching temperature by a heating device (not shown). For example, when the metal plate M is a high-strength steel plate made of iron, it is heated to a temperature of 850 to 1050 ° C. Then, the metal plate M in a high temperature state is conveyed at high speed from the heating device to the hot press working device, and placed on the central convex portion 11 of the lower die 10 as shown in FIG. It arrange | positions between the upper mold | types 20. After the arrangement of the metal plate M is completed, the upper mold base 2 is moved downward without inserting a gap, and the metal plate M is pressed by the lower mold 10 and the upper mold 20 as shown in FIG. To do.

  By the shaping action of the upper and lower molds in this press molding process, the metal plate material M is press-molded into a predetermined shape corresponding to the shape when the lower mold 10 and the upper mold 20 are joined. And the central part of the metal plate M which is pressed by the lower mold central convex part 11 and the upper mold central concave part 22 (that is, the mold part other than the excision target pressing part) in the non-heated state in the lower mold 10 and upper mold 20 Is quenched simultaneously with press molding. On the other hand, in the vicinity of the left and right end portions (that is, the portion to be cut) of the metal plate M sandwiched between the lower die portion 12 and the upper die insert portion 23 preheated by the Peltier module 3, the metal plate material M and the lower die Since there is no large temperature difference between the portion 12 and the upper mold insert portion 23 and there is no significant temperature drop, no baking occurs. Therefore, at this stage, the central portion of the metal plate M starts hardening by quenching prior to the left and right ends, but the left and right ends of the metal plate M maintain a temperature of 600 ° C. or higher and the hardening does not start.

  The upper mold base 2 and the trim are continuously moved from the state shown in FIG. 6 against the upper mold 20 stopped on the lower mold 10 as shown in FIG. By further lowering the blade 5, trim processing is performed on the left and right end portions of the metal plate M held by the lower die portion 12 and the upper die insert portion 23. According to this trim processing, the trim blade 5 that slides from top to bottom along the side surface 21a of the upper die main body and the side surface 23b of the upper die nesting portion, and the side surface 12b of the lower die portion (that is, the fixed side blade surface). In the process of crossing, the left and right ends of the metal plate M are cut off. In this trim processing stage, the part connected to the left and right ends of the metal plate M is not quenched and hardened, and the part is kept in a certain softened state by the heat from the Peltier module 3. Moreover, the cutting of the metal plate material M by the trim blade 5 is performed very smoothly. Therefore, the load on the trim blade 5 is reduced and the blade spills hardly occur.

  Furthermore, in this embodiment, the current control circuit 6 reverses the direction of the direct current flowing through each Peltier module 3 almost simultaneously with the start of trim processing by the trim blade 5. For example, when the sensor detects the occurrence of relative displacement of the trim blade 5 with respect to the upper die 20 stopped by joining to the lower die 10, the direction of the direct current is reversed by the current control circuit 6. Due to the reversal of the direction of the direct current flowing through each Peltier module 3, the upper surface 12a of the left and right die portions of the lower mold and the lower surface 23a of the left and right nested portions of the upper mold are cooled from the previous heating. The surface temperature of 23a falls to room temperature or below. Then, the part of the metal plate M sandwiched between the lower die portion 12 and the upper die insert portion 23 is also quenched.

  As described above, according to the hot pressing method of the present embodiment, the center portion of the metal plate M pressed by the lower mold central convex portion 11 and the upper mold central concave portion 22 in a non-heated state is press-formed. At the same time, while quenching is performed, in the vicinity of the left and right ends of the metal plate M sandwiched between the lower die portion 12 and the upper die insert portion 23 in which the Peltier module 3 is incorporated, a press forming step is performed. In this case, quenching is not performed, and quenching is performed after trim processing, triggered by reversing the direction of the direct current flowing through the Peltier module 3 almost simultaneously with trim processing by the trim blade 5. Thus, the entire metal plate M after press forming and trim processing is uniformly quenched.

  As described above, according to the present embodiment, the heated metal sheet M can be subjected to press forming, trim processing and quenching in a state where the burden on the trim blade 5 is sufficiently reduced as a series of steps. . Therefore, the life of the trim blade 5 can be extended, and the entire metal plate M that has been press-formed and trimmed can be hardened uniformly.

  [Modification] In the above embodiment, the hot press working apparatus and method using the trim blade 5 as the cutting tool have been described, but the hot press working apparatus using the punch 8 for punching as the cutting tool and The present invention can also be applied to a method. For example, as shown in FIG. 8A, a punching punch 8 is provided in a part of the upper die 20 so as to be movable relative to the upper die 20, and the punching punch is provided in the lower die 10. A punch receiving hole (through hole) 9 corresponding to 8 is provided. Further, the Peltier module 3 is incorporated into the cutting target pressing portion 25 of the upper mold 20 surrounding the punching punch 8 and the cutting target pressing portion 15 of the lower mold 10 surrounding the punch receiving hole 9. However, a Peltier module 3 is incorporated to construct a hot press working device. Then, as shown in FIG. 8B, the metal plate M is almost synchronized with the press forming in which the heated metal plate M is clamped by the lower die cutting target pressing portion 15 and the upper die cutting target pressing portion 25. The punch 8 for punching is made to penetrate through the hole. By reversing the direction of the direct current flowing through each Peltier module 3 before and after drilling, the surfaces of the upper and lower cut target pressing portions 15 and 25 are switched from the heated state to the cooled state. According to this method, the drilling process for the metal plate material M and the subsequent quenching of the peripheral portions of the holes of the metal plate material M can be performed continuously and smoothly.

  [Modification] In the above embodiment, the trim blade 5 is provided on the upper die 20 side, but a similar trim blade may be provided on the lower die 10 side.

  [Modification] In the above embodiment, the Peltier module 3 is incorporated in both the lower mold 10 and the upper mold 20, but the Peltier module 3 may be incorporated only in either the lower mold 10 or the upper mold 20.

The front view which shows the outline of the hot press processing apparatus according to one Embodiment. The fragmentary sectional view which expands and shows the part enclosed with the dashed-two dotted line of FIG. The disassembled perspective view which decomposes | disassembles and shows an upper mold | type. The perspective view which shows the outline of a Peltier module. The schematic circuit diagram which shows the electric constitution of the thermoelectric cooling element of a Peltier module. The front view which shows the press molding process by a hot press processing apparatus. The front view which shows the cutting process process and local quenching process by a hot press processing apparatus. (A) And (B) is a schematic sectional drawing which shows another example of excision processing.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 3 ... Peltier module, 5 ... Trim blade (cutting tool), 6 ... Current control circuit, 7 ... DC power supply, 8 ... Punch for drilling (cutting tool), 10 ... Lower mold (first mold or fixing) Mold), 12 ... Die part (removal target pressing part), 15 ... Resection target pressing part, 20 ... Upper mold (second mold or movable mold), 23 ... Nesting part (removal target pressing part), 25 ... Resection target Press part, M ... Metal plate material as a workpiece.

Claims (3)

First and second molds that can be relatively approached and separated, and a cutting tool provided on one side of the first and second molds, press-molded against a heated metal plate, A hot press machine for cutting and quenching,
Each of the first and second molds has an excision target pressing portion capable of pinching by cooperating with or near the excision target portion of the metal plate material by the excision processing tool. A hot press working apparatus, wherein a Peltier module is incorporated in at least one of the cutting target pressing portion of the mold and the cutting target pressing portion of the second mold.   2. The hot press working apparatus according to claim 1, wherein the Peltier module is electrically connected to a DC power source via a current control circuit that controls a direction of a DC current flowing through the Peltier module. The first and second molds capable of relatively approaching and separating, and a cutting tool provided on one side of the first and second molds, wherein the first and second molds are Each of the cutting target pressing portions that can be clamped in cooperation with the cutting target portion of the metal plate material or the vicinity thereof by the cutting tool is provided, and the cutting target pressing portion of the first mold and the second mold At least one of the excision target pressing parts is a hot pressing method of a metal plate using a hot pressing device in which a Peltier module is incorporated,
A preheating step of preheating the surface of the pressing portion to be cut in which a direct current is supplied to the Peltier module and the Peltier module is incorporated;
A press forming step of placing a heated metal plate between the first and second molds and press-molding with the first and second molds;
In synchronism with the press forming, with respect to the portion to be cut of the metal plate material sandwiched between the cut target pressing portion of the first mold and the cut target pressing portion of the second mold at the time of the press forming. A resection process for performing resection with the resection tool;
Simultaneously with or immediately after the excision processing, the direction of the direct current flowing through the Peltier module is reversed, and the surface of the excision target pressing portion in which the Peltier module is incorporated is cooled by reversing from heating. A hot press working method characterized by sequentially executing a local quenching step of quenching a portion to be excised of the metal plate material in contact with the target pressing portion or the vicinity thereof.

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