JP2006224105A - Method for positioning material plate at hot press work - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the positioning accuracy of a material plate at hot press work more than heretofore. <P>SOLUTION: A material plate 4 in a heated condition is primary-positioned by a nest mechanism to a lower die 2 for pressing. Next, a conical first position-adjusting pin 25 and a square pyramid second position adjusting pin 26 are protruded from the lower die 2, and inserted in a round hole 41 and a long hole 42 formed in the material plate 4 in advance, respectively. In a process in which the two position adjusting pins 25, 26 are protruded, edges of the holes 41, 42 of the material plate 4 are guided by a tapered outer face or an edge of each pin, and the position of the primary-positioned material plate 4 is re-adjusted based on the position adjusting pins 25, 26. The material plate 4 is secondary-positioned more precisely with respect to the lower die 2 for pressing. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for positioning a material plate in hot pressing.

  There is known a hot press process that simultaneously achieves forming and quenching by pressing a heated metal plate with a relatively low-temperature press die (see, for example, Patent Document 1). According to the processing method, the metal plate material is conveyed to a pressing mold (upper mold and lower mold) immediately after heating, positioned on a fixed mold (lower mold), and then pressed with a movable mold (upper mold). Usually, a positioning mechanism called a nest is used for positioning the plate material with respect to the lower mold (see, for example, Patent Document 2 for the nest). For example, after placing the plate material on the lower mold, with the movable nest, one side of the plate material is pushed horizontally toward the opposite side, and the opposite side of the plate material is brought into contact with the fixed nest, so that the position of the lower mold and the plate material is Aligning. This operation is generally called “centering”.

  However, when the metal plate is heated, the frictional resistance increases and it becomes difficult to slip. For this reason, in the positioning of the plate material by the nest, some misalignment tends to remain, and hot pressing is performed with low positioning accuracy, and defective products are likely to occur. Also, especially in hot pressing, the tensile strength (or hardness) of the resulting product is very high, so it is difficult to perform trim processing and piercing with a press machine after hot pressing, and press before hot pressing. It is necessary to finish trimming with a machine. Under such circumstances, how to improve the positioning accuracy of the material plate during hot pressing is a technical issue.

JP 2002-102980 A JP 2001-252728 A (paragraph 0002, etc.)

  The objective of this invention is providing the positioning method of the material board which can improve the positioning accuracy of the material board at the time of a hot press process conventionally.

  The invention of claim 1 is a method of positioning a material plate with respect to a press die during hot pressing, and after the primary positioning of the material plate in a heated state by a nest mechanism, Hot and hot positioning, wherein the material plate is further precisely positioned by projecting a conical or polygonal pyramid-shaped position adjustment pin from the press mold and engaging it with a hole formed in the material plate in advance. This is a method for positioning a material plate in press working.

  The invention of claim 2 is a method of positioning a material plate with respect to a press die during hot pressing, and after the primary positioning of the material plate in a heated state by a nest mechanism, A cone-shaped first position adjustment pin and a cone or polygonal pyramid-shaped second position adjustment pin protrude from the press mold, and a round hole corresponding to the first position adjustment pin formed in advance on the material plate and This is a method for positioning a material plate in hot pressing, characterized in that the material plate is secondarily positioned more precisely by engaging the elongated holes corresponding to the second position adjusting pins.

  According to a third aspect of the present invention, in the method for positioning a material plate in hot pressing according to the second aspect, the material plate is a long plate, and the round holes and the long holes are arranged in the longitudinal direction of the plate. The elongated hole extends long along the longitudinal direction of the plate material.

  Invention of Claim 4 is the positioning method of the material board in the hot press processing of Claim 3, The said nest mechanism is a fixed nest (33a) used as the positioning reference of the longitudinal direction in a long material board, A movable nest (33b) that pushes the material plate toward the fixed nest, and at the time of the primary positioning, the round hole is closer to the fixed nest (33a) and the elongated hole is moved to the movable nest (33b). In the press mold, a first position adjustment pin corresponding to the round hole and a second position adjustment pin corresponding to the elongated hole are arranged and set so as to be arranged closer to each other. .

[Action]
According to the first to fourth aspects, the material plate is primarily positioned with respect to the press mold by the nest mechanism. Thereafter, a conical or polygonal pyramid-shaped position adjusting pin is projected from the pressing mold, and is inserted into a hole formed in advance in the material plate. The edge of the hole in the material plate is guided to the taper outer surface or edge of the pin in the process of projecting the cone or polygonal pyramid type alignment pin, and the position of the primary positioned material plate is readjusted with reference to the alignment pin The In this way, the material plate is secondarily positioned more precisely with respect to the press mold.

  According to the second, third, and fourth aspects, the accuracy of the secondary positioning is increased by using at least two position adjusting pins. In addition, when the round hole is considered as the reference hole, the distance from the round hole to the long hole may change due to the thermal expansion of the heated material plate, but the hole corresponding to the second position adjustment pin is long. Since it is a hole, even if the distance between both holes changes to some extent, the second position adjusting pin can be reliably engaged with the elongated hole. Further, according to the fourth aspect, the first position adjustment pin (pin corresponding to the round hole) serving as the reference for the secondary positioning is arranged and set so as to be close to the fixed nest serving as the longitudinal reference for the primary positioning. Therefore, the positioning accuracy in the longitudinal direction is further increased.

  According to the present invention, the primary positioning of the material plate by the nest mechanism is followed by the secondary positioning process of performing the secondary positioning by the cone or polygonal pyramid type position adjustment pin. In spite of the fact that the slippage is poor, the positioning accuracy of the material plate during hot pressing can be improved as compared with the prior art.

  An embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 1, a press die for hot pressing (for die quenching) is composed of a lower die 2 and an upper die (not shown). The lower mold 2 has a long shape corresponding to a metal material plate 4 (see FIG. 2) to be processed, and includes a water cooling means (not shown) inside. A nest mechanism 3 for primary positioning and a pin mechanism (25, 26) for secondary positioning are provided on the lower mold 2 and its periphery.

  The primary positioning nest mechanism 3 includes three pairs of nests, each of which includes a fixed nest (31a, 32a, 33a) and a movable nest (31b, 32b, 33b) facing each other. Each movable nest includes a drive cylinder 34 for positioning operation. As shown in FIGS. 1 and 2, two fixed nests 31a are provided on one side of two sides along the longitudinal direction of the lower mold 2 (or the material plate 4 placed on the lower mold 2). 32a, and two movable nests 31b and 32b facing these fixed nests are disposed on the other side. In addition, one fixed nest 33a is arranged on one side of the two sides along the width direction of the lower mold 2 (or the material plate 4 placed on the lower mold 2), and the other On the side of the side, one movable nest 33b facing the side is arranged. The three fixed nests (31a, 32a, 33a) serve as the primary positioning reference for the material plate 4 by the nest mechanism 3.

  As shown in FIG. 1 and FIG. 3, the lower mold 2 has a flat molding part 21 that is substantially horizontal at the center thereof, and has a curved molding part 22 that is gently curved before and after the flat molding part 21. Yes. First and second pin guide holes 23 and 24 extending in the vertical direction are formed in the vicinity of the front and rear end portions of the flat molding portion 21. First and second position adjustment pins 25 and 26 are inserted into the first and second pin guide holes 23 and 24, respectively.

  The first position adjusting pin 25 is configured as a generally conical pin in which the upper end portion has a conical shape and the other portion has a cylindrical shape. The first pin guide hole 23 has a circular cross section corresponding to the first position adjustment pin 25. On the other hand, the second position adjusting pin 26 has a generally quadrangular pyramid shape in which the upper end portion has a substantially rhombic quadrangular pyramid shape in plan view and the other portion has a substantially rhombic prism shape in cross section that is continuous with the quadrangular pyramid shape. It is configured as a pin. The second pin guide hole 24 has a substantially rhombic cross section corresponding to the second position adjustment pin 26. The first and second position adjusting pins 25 and 26 are in a submerged position (see FIG. 3A) where the upper end of each pin is immersed in the lower mold by a drive mechanism (not shown), and the upper end of each pin is lower. It is possible to move vertically between the protruding position protruding above the upper surface of the mold 2 (see FIG. 3B).

  The material plate 4 to be processed (worked) by hot pressing is a high-tensile steel plate having a tensile strength of 500 to 600 MPa, for example, and is a long plate having a length much larger than the width (see FIG. 2). ). On the center line C of the material plate 4, a round hole 41 and a long hole 42 are formed at a predetermined interval. The round hole 41 corresponding to the first position adjustment pin 25 has a circular shape having a diameter substantially corresponding to the diameter of the first position adjustment pin 25 (see FIG. 3D). On the other hand, the long hole 42 corresponding to the second position adjustment pin 26 has a width (a) substantially corresponding to the length (a) along the lower mold width direction of the second position adjustment pin 26, and the second The position adjusting pin 26 has an oval shape with a length (d) that is clearly larger than the length (b) along the lower die longitudinal direction (see FIG. 3C).

  Next, the positioning procedure of this embodiment using the positioning mechanism will be described.

  First, the first and second position adjustment pins 25 and 26 of the lower mold 2 are arranged at the immersion positions. A material plate 4 heated to, for example, 850 ° C. or higher by a heating device (not shown) is conveyed at high speed between the lower mold 2 and the upper mold. At that time, the material plate material 4 is placed on the planar molding portion 21 of the lower mold 2 so that the round hole 41 is positioned not on the movable nest 33b but on the fixed nest 33a. Then, the movable nest (31b, 32b, 33b) is operated, and the material plate 4 is slid toward the fixed nest (31a, 32a, 33a) with these movable nests, whereby the fixed nest 33a is positioned in the longitudinal direction. Using the fixed nests 31 a and 32 a as a position reference in the width direction, the material plate 4 is primarily positioned with respect to the lower mold 2.

  When the material plate 4 is in a heated state, the slippage of the plate is deteriorated, and the positioning accuracy of the material plate 4 may not be sufficient in the primary positioning by the nest mechanism 3. Therefore, in order to increase the positioning accuracy of the material plate 4, secondary positioning by the pin mechanism (25, 26) is performed. That is, the first and second position adjusting pins 25 and 26 at the immersion position in FIG. 3A are projected to the projecting position in FIG. At that time, the material plate 4 is positioned with a certain degree of accuracy by the primary positioning, and even if the distance from the round hole 41 to the elongated hole 42 is slightly changed due to the thermal expansion of the heated material plate 4. Since the hole 42 corresponding to the second position adjustment pin 26 is a long hole, the upper end portions of the position adjustment pins 25 and 26 are always engaged with the corresponding round hole 41 and long hole 42, respectively.

  Then, in the process in which the position adjusting pins 25 and 26 protrude, the edges of the holes 41 and 42 of the material plate material are guided by the tapered outer surface or edge of the upper end portion of each pin. Specifically, as the first position adjustment pin 25 having a conical upper end projects, the round hole 41 of the material plate 4 is guided by the tapered conical outer surface of the upper end of the pin. As a result, the position of the material plate 4 is finely adjusted so that the eccentricity of the center of the round hole 41 with respect to the central axis of the first position adjusting pin 25 is eliminated as much as possible.

  Further, as the second position adjustment pin 26 having a quadrangular pyramid upper end projects, the elongated hole 42 of the material plate 4 is guided by the tapered isosceles triangular edge of the upper end of the pin. As a result, the material plate 4 is arranged so that the discrepancy between the center axis of the second position adjusting pin 26 and the center line (or virtual vertical surface) that bisects the width (a) of the long hole 42 is eliminated. The position of is finely adjusted. The fine adjustment by the second position adjustment pin 26 is performed in the horizontal plane of the material plate 4 using the first position adjustment pin 25 based on the fitting relationship between the first position adjustment pin 25 and the round hole 41 as a rotation axis. This corresponds to the positioning adjustment that restricts the rotation.

  That is, in this embodiment, the longitudinal direction reference and the width direction reference in the secondary positioning are determined by the fitting of the first position adjustment pin 25 and the round hole 41. Further, by engaging the isosceles triangular edge of the second position adjusting pin 26 and the two parallel sides of the elongated hole 42 in synchronization with the fitting of the first position adjusting pin 25 and the round hole 41, A reference in the width direction in the secondary positioning of the long plate 4 is determined.

  In this way, by performing secondary positioning of the material plate 4 that has been primarily positioned by the pin mechanism (25, 26), the position of the material plate 4 is readjusted, and precise positioning of the material plate 4 with respect to the lower mold 2 is achieved. . Then, after the two position adjusting pins 25 and 26 are immersed in the lower mold 2 or in synchronization with the immersion operation, the heated material plate 4 is pressed between the lower mold 2 and the upper mold. A desired hot-pressed product is obtained.

  Examples of processed products by this method include vehicle parts such as bumper reinforcements for vehicles, door impact beams, side members, front pillar reinforcements, center pillar reinforcements, rear pillar reinforcements, and roof reinforcements. it can.

  According to the present embodiment, since the material plate 4 can be positioned very precisely with respect to the lower mold 2 as a press mold, a press-processed product with excellent dimensional accuracy is produced with almost no defective products. be able to. In particular, since the positioning accuracy at the time of pressing is high, piercing and trimming can be performed on the material plate 4 in advance with peace of mind. Since piercing and trimming can be performed in advance before press forming, the total processing cost until product completion can be greatly reduced.

  [Modification] In the above embodiment, the second position adjustment pin 26 corresponding to the long hole 42 is a quadrangular pyramid pin having a substantially rhombus shape in plan view, but this is a conical pin or a hexagonal shape or more in plan view. It may be replaced with a polygonal pyramid pin.

  [Modification] In the above embodiment, the hole corresponding to the second position adjustment pin 26 is the long hole 42, but it may be a round hole instead of the long hole 42.

  [Modification] In the embodiment described above, the second position adjustment pin 26 corresponding to the elongated hole 42 is provided in the planar molding portion 21 of the lower mold 2, but the curved surface of the lower mold 2 is used for the second position adjustment pin 26. You may arrange | position in the shaping | molding part 22. FIG.

The perspective view which shows the outline | summary of the metal mold | die (lower mold) for hot press work, and various positioning mechanisms. The top view which shows the outline | summary when a material board | plate material is primarily positioned by a nest mechanism. (A) and (B) are schematic cross-sectional views taken along the line Q-Q in FIG. 2, and (C) and (D) are schematic plan views showing the relationship between the long hole or round hole of the material plate and the position adjustment pin of the lower mold. .

Explanation of symbols

  2 ... Lower mold (press mold), 3 ... Nest mechanism, 4 ... Material plate material, 25 ... First position adjustment pin, 26 ... Second position adjustment pin, 31a, 32a, 33a ... Fixed nest, 31b, 32b, 33b ... movable nest, 41 ... round hole (reference hole) in material plate, 42 ... long hole in material plate.

Claims (4)

A method of positioning a material plate with respect to a press mold during hot pressing,
After primary positioning of the heated material plate to the press mold by the nest mechanism,
Hot and hot positioning, wherein the material plate is further precisely positioned by projecting a conical or polygonal pyramid-shaped position adjustment pin from the press mold and engaging it with a hole formed in the material plate in advance. A method for positioning a material plate in press working. A method of positioning a material plate with respect to a press mold during hot pressing,
After primary positioning of the heated material plate to the press mold by the nest mechanism,
A cone-shaped first position adjustment pin and a cone or polygonal pyramid-shaped second position adjustment pin protrude from the press mold, and a round hole corresponding to the first position adjustment pin formed in advance on the material plate and A method for positioning a material plate in hot pressing, wherein the material plate is subjected to secondary positioning more precisely by engaging the elongated holes corresponding to the second position adjusting pins, respectively.   3. The material plate material is a long plate material, and the round hole and the long hole are arranged in a longitudinal direction of the plate material, and the long hole extends long along the longitudinal direction of the plate material. A method for positioning a material plate in the hot pressing described above. The nest mechanism includes at least a fixed nest (33a) serving as a longitudinal positioning reference for a long material plate and a movable nest (33b) for pushing the material plate toward the fixed nest.
In the primary positioning, the first hole corresponding to the round hole in the pressing die is arranged so that the round hole can be arranged closer to the fixed nest (33a) and the elongated hole can be arranged closer to the movable nest (33b). 4. The method for positioning a material plate in hot press working according to claim 3, wherein a position adjusting pin and a second position adjusting pin corresponding to the elongated hole are arranged and set.

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