JP2005271038A - Hot press processing method and apparatus - Google Patents

Abstract

The present invention relates to a method for hot pressing a steel material, and aims to increase production speed.
A press forming apparatus 18 includes a die forming portion capable of simultaneously press forming a plurality of steel materials 30a, 30b, 30c. The positioning device 10 sets a plurality of steel materials 30a, 30b, 30c in a predetermined relative positional relationship for simultaneous pressing in the press forming device. While maintaining this positional relationship, the plurality of steel materials 30a, 30b, 30c are introduced into the heating furnace 14 and heated to the quenching temperature. The heated steel materials 30a, 30b, and 30c are introduced into the corresponding mold forming portions maintained at a low temperature of the press device 18 while maintaining the mutual positional relationship, and the steel materials 30a, 30b, and 30c are subjected to simultaneous forming and rapid cooling. Quenching is performed.
[Selection] Figure 1

Description

  The present invention relates to a hot press working method for steel that heats a steel to its quenching temperature, presses the heated steel with a low-temperature mold and quenches the steel, and a hot press working apparatus for steel in the present invention.

In hot pressing, the steel material to be subjected to press forming is heated to its quenching temperature (austenite temperature) such as 750 to 1000 ° C., and the heated steel material is introduced and formed in a mold, and the heated steel material is pressed. During molding, it is rapidly cooled by a low-temperature mold, becomes a martensite structure, and is hardened (quenched). Therefore, despite the fact that an independent quenching process is not required, it is possible to press-mold high-strength and high-precision products, and a relatively low-cost steel material with a low chromium content, such as a tensile strength of 50-60 kp / mm2. (Blank) can be used as a starting material to obtain 150-170 kp / mm2 high-strength final products at low cost, and is also suitable for the production of press-molded body parts such as automobile door impact beams ( Patent Document 1).
British Patent No. 1490535

  In conventional hot press processing, heated steel materials are introduced into a press forming apparatus one by one and pressed. In the press working apparatus, in order to perform quenching reliably, the mold clamping requires a time of about 20 seconds at the shortest. When the steel material for forming, from the forming process through the forming process to unloading is included, a total time of at least about 30 seconds is required, and only about two products can be obtained per minute.

  The present invention has been made in view of the problems of the prior art, and aims to increase the production speed in hot press processing.

  According to the first aspect of the present invention, in a hot press working method of a steel material in which the steel material is heated to its quenching temperature, and the heated steel material is press-molded and quenched by a low temperature mold, from heating to press molding. There is provided a method for hot pressing a steel material, characterized in that a plurality of materials are simultaneously processed while maintaining a predetermined relative positional relationship as it is in a series of steps.

  According to invention of Claim 2, in the hot press processing method, the press molding apparatus provided with the separate metal mold forming part which can press-mold several steel materials simultaneously is prepared, and several steel materials are used in press molding apparatus. Set to a predetermined relative positional relationship for simultaneous pressing, introduce a plurality of steel materials into the heating furnace in this set positional relationship, and maintain the positional relationship to a plurality of steel materials up to the quenching temperature By heating and introducing a plurality of heated steel materials into a press molding apparatus from a heating furnace while maintaining the mutual positional relationship, a plurality of steel materials are simultaneously press-molded in a corresponding mold forming section maintained at a low temperature. There is provided a hot pressing method characterized by quenching together.

  According to the third aspect of the present invention, a heating furnace, a press molding apparatus provided with a separate mold forming section capable of simultaneously press-molding a plurality of steel materials, and simultaneous press working of the plurality of steel materials in the press-molding apparatus. Positioning device for setting a predetermined relative positional relationship, first steel material handling means for introducing a plurality of steel materials positioned by the positioning device into the heating furnace while maintaining the predetermined relative positional relationship, and quenching in the heating furnace A second steel material handling means for taking out a plurality of steel materials heated to a temperature while maintaining the relative positional relationship and introducing the steel materials into a corresponding mold forming part maintained at a low temperature of the press device; A hot press working apparatus is provided, in which each of the mold forming parts is simultaneously press-molded and quenched.

  The operation and effect of the invention of claim 1 will be described. A plurality of materials are simultaneously processed with respect to a plurality of steel materials while maintaining a predetermined relative positional relationship in a series of steps from heating to press forming, that is, heating and pressing. Processing is performed. Therefore, the production efficiency can be increased by the number of steel materials that are simultaneously processed.

  The operation and effect of the invention of claim 2 will be described. A plurality of steel materials are transferred to a heating furnace in a state in which a predetermined relative positional relationship for simultaneous pressing in a press forming apparatus set prior to hot pressing is maintained. Introduction and heating, and further, carrying from the heating furnace to the press forming apparatus and press forming are performed. Therefore, the process from heating to press molding can be continued regardless of the time of 30 seconds required for hot pressing of steel materials, and the production efficiency can be increased to the limit.

  The operation and effect of the invention of claim 3 will be described. A plurality of steel materials are set in a predetermined relative positional relationship for simultaneous pressing in the press molding device by the positioning device, and a plurality of steel materials are maintained while maintaining this positional relationship. The first steel material handling means and the second steel material handling means are carried into the heating furnace and from the heating furnace into the pressing device, so that simultaneous hot pressing of a plurality of steel materials can be efficiently performed continuously and automatically. Can be implemented.

  FIG. 1 shows an overall schematic configuration of a hot press working apparatus of the present invention. A positioning apparatus 10, a first robot 12 for material handling (first steel material handling means of the present invention), a heating furnace 14, A second robot 16 for material handling (second steel material handling means of the present invention) and a press molding apparatus 18 are configured.

  As shown in FIG. 2, the press molding device 18 is provided with a slide table 20 connected to a piston rod of a hydraulic cylinder (not shown) and a bolster table 22 fixed to a frame of the press device. An upper mold set 24 is attached to the lower surface of the slide table 20, and a lower mold set 26 is attached to the upper surface of the bolster table 22. Steel material is formed between the upper mold set 24 and the lower mold set 26. In this embodiment, three steel materials (blank plates) can be simultaneously formed in this embodiment. That is, the upper mold set 24 includes three upper mold forming portions 24a, 24b, and 24c installed in parallel, while the lower mold set 26 includes three lower mold forming portions 26a, 26b, 26c, and blank plates 30a, 30b, and 30c are simultaneously formed between the upper and lower mold forming portions of each pair, that is, between 24a and 26a, between 24b and 26b, and between 24c and 26c. That is, three blank plates 30a, 30b, 30c are introduced in the state of FIG. 2 (a) when the mold is opened, and are set on the lower mold forming portions 26a, 26b, 26c. The lower die set 26 is a well-known positioning pin (denoted by 31 in FIG. 3) for setting the three blank plates 30a, 30b, 30c to the desired positions with respect to the corresponding lower die forming portions 26a, 26b, 26c. Positioning means is provided at both ends. Each of the blank plates 30a, 30b, 30c is provided with positioning holes (indicated by 33 in FIG. 3) inserted into the corresponding positioning pins at both ends. Therefore, the positioning pins are inserted into the positioning holes. By doing so, the blank plates 30a, 30b, 30c can be correctly positioned on the corresponding lower mold forming portions 26a, 26b, 26c. In other words, when the blank plates 30a, 30b, 30c are correctly positioned on the lower mold set 26, the blank plates 30a, 30b, 30c are in a predetermined relative positional relationship with each other. FIG. 3 schematically shows the positioning of the blank plate by the positioning pins 31 on the lower mold set 26 and the positioning holes 33 on the blank plates 30a, 30b, 30c.

  When the hydraulic cylinder is driven from the mold open state of FIG. 2 (a), the slide table 20 is lowered to reach the mold clamping state shown in FIG. 2 (b). At this time, the upper mold forming parts 24a, 24b, 24c are The blank plates 30a, 26b, and 26c are combined with the lower mold forming portions 26a, 26b, and 26c, and the blank plates 30a, 30b, and 30c are simultaneously press-formed between the upper and lower dies 24a and 26a, between 24b and 26b, and between 24c and 26c.

  In FIG. 2, the upper mold set 24 and the lower mold set 26 are provided with cooling means such as cooling water passages 32 and 34, and are quenched by quenching during the formation of the heated blank plates 30a, 30b, and 30c. It can be performed.

  In FIG. 1, the positioning device 10 uses the blank plates 30a, 30b, 30c as relative positions of the blank plates 30a, 30b, 30c for pressing in the press molding device 18 (between the upper and lower molds 24a-26a, 24b-26b, 24c- The positions of the blank plates 30a, 30b, and 30c in the horizontal plane xy between the blank plates 30a, 30b, and 30c are determined at the same time. That is, the positioning device 10 includes three pairs of positioning blocks 40a, 40b, and 40c, and the blank plates 30a, 30b, and 30c are arranged in the vertical and horizontal directions (x and y positions) on the positioning blocks 40a, 40b, and 40c. In a state where the blank plates 30a, 30b and 30c are mounted on the corresponding positioning blocks 40a, 40b and 40c, the blank plates 30a, 30b and 30c are simultaneously pressed by the press molding apparatus 18 with the blank plates 30a, 30b and 30c. For mutual position.

  In FIG. 1, the first robot 12 for material introduction grips blank plates 30 a, 30 b, 30 c positioned in a predetermined relative positional relationship by the positioning device 10, and introduces them into the heating furnace 14 while maintaining the relative positional relationship. . That is, as shown in FIG. 4, an openable / closable gripping arm 42 is attached to the first robot 12, and the gripping arm 42 is provided with three pairs of gripping portions 44a, 44b, 44c. The blank plates 30a, 30b, 30c are gripped by 44b, 44c, and the robot arm is appropriately rotated on each axis to convey the blank plates 30a, 30b, 30 while maintaining the intended relative position in the horizontal plane xy. be able to. The material input second robot 16 has the same configuration as that of the first robot 12, and has a gripping arm 45 for transporting the blank plates 30a, 30b, 30c while maintaining a predetermined positional relationship. I have.

  The heating furnace 14 heats steel materials (blank plates 30a, 30b, 30c) to the quenching temperature, and includes a heater 46, and conveys the blank plates 30a, 30b, 30c while maintaining a predetermined positional relationship. (See FIG. 5).

  Next, the hot press working method by the hot press working apparatus of the present invention will be described. As shown in FIG. 4, blank plates 30a, 30b, 30c, which are steel materials to be processed, correspond to respective pairs of positioning blocks of the positioning apparatus 10. 40a, 40b, 40c. And well-known means (not shown) such as a pusher for positioning the blank plates 30a, 30b, 30c placed on the positioning blocks 40a, 40b, 40c is provided. This positioning step is performed so that the relative position between the blank plates 30a, 30b, 30c on the positioning blocks 40a, 40b, 40c matches the relative position between the blank plates 30a, 30b, 30c in the press device 18. .

  Next, the blank plates 30a, 30b, 30c positioned in this way are gripped by the corresponding gripping portions 44a, 44b, 44c in the gripping arm 42 attached to the first robot 12, and are positioned blocks 40a, 40b, 40c. It is taken out more. The blank plates 30a, 30b, 30c gripped by the gripping arm 42 are introduced into the heating furnace 14 by an appropriate turning operation of the corresponding rotating shaft of the robot arm, as shown in FIG. Placed on. Accordingly, the blank plates 30a, 30b, and 30c are conveyed on the conveyor 48 while maintaining the relative positions set by the positioning device 10, and are heated by the heater 46 in the meantime to achieve the hardening temperature of the steel material (so-called austenite state). Although the temperature varies depending on the steel composition, it is heated to a temperature in the range of 750 to 1000 ° C., for example. In the heating furnace 14, another set of blank plates 30 a, 30 b, 30 c can be sequentially heat-treated, and during the holding at the bottom dead center for pressing and cooling the set of blank plates in the press device. Next, the heating of the blank plate to be pressed next is completed, and immediately after the heating is completed, the process proceeds to the press forming process of the next steel material by the press forming apparatus 18, and the production efficiency can be maximized.

  The blank plates 30a, 30b, 30c heated to the curing temperature are gripped by the gripping arm 45 of the second robot 16 as shown in FIG. 6 while securing the relative position, taken out from the heating furnace 14, and the mold is opened. 18 is introduced between the upper mold set 24 and the lower mold set 26, and the blank plates 30a, 30b, 30c are set at predetermined positions on the lower mold. That is, since the blank plates 30a, 30b, and 30c are held and carried at mutual positions for simultaneous processing by the press device, the blank plates 30a, 30b, and 30c can be handled only by the input operation by the second robot 16. Expected positions on the lower mold parts 26a, 26b, 26c (positions where the positioning holes 33 of the blank plates 30a, 30b, 30c are inserted into the corresponding positioning pins 31 on the lower mold as schematically shown in FIG. ) Can be set as is. This set state is shown in FIG. Then, the slide table 20 is lowered by hydraulic control to the hydraulic cylinder of the hydraulic press device, the upper and lower mold forming portions 24a, 26a; 24b, 26b; 24c, 26c are united, and the blank plates 30a, 30b, 30c are press-molded simultaneously. Is done. The mold clamping state is maintained for a period of 30 seconds, and the molded product is quenched and quenched by the low temperature molds 24 and 26. The mold is opened by raising the slide table 20 after a predetermined time, and three products can be taken out simultaneously.

  According to the present invention, since a plurality of steel materials are processed simultaneously while maintaining a predetermined relative positional relationship between a plurality of materials in a series of processes from heating to press forming, a single steel material is hot pressed. High production efficiency can be obtained regardless of the limitation of the clamping time of about 30 seconds required for the process.

FIG. 1 is a schematic plan view of the entire system for hot pressing according to the present invention. FIG. 2 is a schematic longitudinal sectional view of the press molding apparatus in FIG. FIG. 3 is a perspective view schematically showing a method of positioning a plurality of steel materials in the mold of the press molding apparatus of FIG. FIG. 4 is a perspective view schematically showing removal of a plurality of steel materials from the positioning device by the first robot. FIG. 5 is a perspective view schematically showing the conveyance of a plurality of steel materials to the heating furnace by the first robot. FIG. 6 is a perspective view schematically showing conveyance of a plurality of steel materials from the heating furnace to the press forming apparatus by the second robot.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Positioning device 12 ... 1st robot 14 ... Heating furnace 16 ... 2nd robot 18 ... Press molding apparatus 20 ... Slide table 22 ... Bolster table 24 ... Upper die set
24a, 24b, 24c ... Upper mold part 26 ... Lower mold set
26a, 26b, 26c… Lower mold part
30a, 30b, 30c… Blank plate
32, 34… Cooling water passage
40a, 40b, 40c ... positioning block 42 ... gripping arm
44a, 44b, 44c ... gripping portion 45 ... gripping arm 46 ... heater 48 ... conveyor

Claims (3)

  In a method of hot pressing a steel material in which the steel material is heated to its quenching temperature, and the heated steel material is press-molded and quenched by a low-temperature mold, a plurality of materials are determined in a series of steps from heating to press molding. A method of hot pressing a steel material, wherein a plurality of steel materials are simultaneously processed while maintaining a relative positional relationship.   In a hot press processing method, a press forming device having a separate mold forming part capable of simultaneously press-forming a plurality of steel materials is prepared, and a predetermined relative positional relationship for simultaneous pressing in the plurality of steel materials in the press-forming device is prepared. In this manner, a plurality of steel materials are introduced into the heating furnace in the set positional relationship, and the plurality of steel materials are heated to the quenching temperature while maintaining this positional relationship, and the heated steel materials are mutually connected. The hot press process is characterized in that a plurality of steel materials are simultaneously press-formed and quenched in a corresponding mold-forming part maintained at a low temperature by introducing them into a press-forming device from a heating furnace while maintaining the positional relationship of Method. A heating furnace, a press forming device with a separate mold forming part capable of simultaneously pressing a plurality of steel materials, and positioning for setting a plurality of steel materials in a predetermined relative positional relationship for simultaneous pressing in the press forming device Apparatus, first steel material handling means for introducing a plurality of steel materials positioned by a positioning device into a heating furnace while maintaining a predetermined relative positional relationship, and a plurality of steel materials heated to a quenching temperature in the heating furnace. The second steel material handling means for taking out while maintaining the relative positional relationship and introducing it into the corresponding mold forming section maintained at a low temperature of the press device, and simultaneously pressing a plurality of steel materials in each mold forming section. And a hot press working device characterized by quenching.

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