JP4977173B2 - Mold and metal container manufacturing method using the same - Google Patents

Description

The present invention relates to a mold and a metal container manufacturing method for manufacturing a metal container.
The term “container” here refers to a bottomed cup-shaped product having a bottom wall and a side wall, and is included in the “container” regardless of whether it is a finished product or a semi-finished product. Its use is not particularly limited. For example, a semi-finished product such as a bottomed cylindrical liner which is an intermediate processed product before being processed into a final product is included together with a metal pressure vessel as a final product.

Conventionally, metal containers, such as aluminum, iron, and stainless steel, are used for the pressure vessel filled with high-pressure gas. When manufacturing such a metal container, a cylindrical bottomed container is manufactured by drawing using a disk-shaped metal material (blank) as a workpiece.
In general, in the drawing process, a plate-like material that is a workpiece is placed on a die in which holes (referred to as die holes) are formed. Next, the bottom wall and the side wall are processed by pressing the punch toward the die hole and pushing the plate material into the die hole (see Patent Document 1).

  When it is desired to manufacture a deep container having a long side wall, the drawing process in one step exceeds the limit drawing ratio and may break. In that case, the workpiece is formed into a large-diameter cup shape by drawing with a large-diameter mold (punch and die), then replaced with a small-diameter mold and the second drawing is performed. A redrawing process for processing into a desired cup shape is used (see Patent Document 2). In the case of forming a deeper container, three or more dies are exchanged and redrawing is performed so as not to exceed the limit drawing ratio.

JP 05-305359 A Japanese Patent Laid-Open No. 06-234029

  Fuel cell vehicles are being developed as next-generation vehicles to replace vehicles that run on fossil fuels such as gasoline. In a fuel cell vehicle, an on-vehicle high-pressure gas container for filling hydrogen gas used as fuel is mounted. The on-vehicle high-pressure gas container is required to have a large capacity by making it as long as possible within a vehicle width.

  In order to manufacture a long container from a disk-shaped metal material (blank), it is necessary to process so as not to exceed the limit drawing ratio as described above. For this reason, it is conventionally necessary to prepare a plurality of molds. was there. In addition, at the time of processing, it is necessary for an operator to move and process a metal material between a plurality of press devices each having a different mold attached thereto, or to perform processing while exchanging the die with one press device. It took time and effort.

  Therefore, in the present invention, if a single die is used for normal drawing, the limit drawing ratio will be exceeded. Therefore, a metal container having a depth that cannot be machined is set in a single press device. It is an object of the present invention to make it possible to manufacture a mold without performing an operation of exchanging the mold on the way.

The mold of the present invention made to solve the above-mentioned problems is a mold for producing a bottomed container from a disk-shaped metal material, and includes a cylindrical molding punch and an outer lower side of the molding punch. And a hollow cylindrical molding die that is coaxially disposed at the position of the molding punch and into which the molding punch can be inserted inside during processing. Also, the outer diameter of the forming die is larger than the outer diameter of the forming die, and alternately and coaxially arranged at the outer position of the forming die and the outer position of the forming die, and before processing by the forming punch and the forming die. At least one hollow cylindrical auxiliary punch for performing auxiliary bending and at least one hollow cylindrical auxiliary die. The forming punch and the auxiliary punch are configured independently of each other so as to move up and down independently one by one. Furthermore, the upper surface of the forming die and the upper surface of each auxiliary die are adjusted to the same height so as to simultaneously support the lower surface of the disk-shaped metal material. Each auxiliary punch is inserted between an auxiliary die disposed opposite to the outer lower position of each auxiliary punch during processing, an auxiliary die disposed opposite to the inner lower position, or a forming die to bend the metal material. An annular groove including a vertical wall is formed.

Here, “auxiliary bending” refers to temporary provisional bending performed at an intermediate stage of processing. The annular groove formed by the bending process at this time is further deformed in a later step.
In addition, “cylindrical molding punch”, “hollow cylindrical molding die”, “hollow cylindrical auxiliary punch”, and “hollow cylindrical auxiliary die” are the parts that contribute to the processing of metal materials as molds. The shape refers to the shape, and there is no particular limitation on the shape and mounting structure of the joint portion where these are attached to the press device.

  Moreover, the metal container manufacturing method of this invention made | formed in order to solve the said subject uses a metal mold | die mentioned above, and a bottomed container is made from the disk-shaped metal raw material mounted on the shaping | molding die and the auxiliary die. A metal container manufacturing method for manufacturing, wherein (a) a step of lowering the outermost auxiliary punch and performing an auxiliary bending process to form an annular groove including a vertical wall in a disk-shaped metal material (B) After returning the auxiliary punch lowered in the previous step, the auxiliary punch inside one is lowered so long as the inner vertical wall of the annular groove formed in the immediately preceding step is not lost, and an auxiliary bending process is performed. And forming a new annular groove having a vertical wall, then performing the same descending and returning to the inner auxiliary punch one by one, and repeating until the innermost auxiliary punch is lowered, ( c) After returning the innermost auxiliary punch, outside the forming die The step of forming the bottomed container from the bottom side by lowering the forming punch within the range where the vertical wall formed on the side does not disappear, and (d) remaining on the outside of the forming die in the previous step Lowering the outermost auxiliary punch capable of performing auxiliary bending on the metal material at that time, performing auxiliary bending, and thereafter repeating steps (b) to (d) A bottomed container is manufactured by drawing a metal punch with a forming punch and a forming die.

According to the present invention, first, in step (a), the outermost auxiliary punch is lowered to perform auxiliary bending, and an annular groove is formed at a position where the auxiliary punch is pressed down on the metal material. Is molded. At this time, the auxiliary punch is lowered until a vertical wall is formed in the annular groove (along the side wall of the die).
Subsequently, in the step (b), the outermost auxiliary punch is returned to the original position, and the inner auxiliary punch is lowered to form the second annular groove. At this time, a partial drawing process is performed in the region of the second annular groove, and the vertical wall inside the first annular groove formed earlier is deformed (becomes shorter gradually). However, until the vertical wall is shortened and completely disappeared, the diameter change of the metal material outside the vertical wall can be temporarily suppressed. That is, the force required for processing is mainly a force required to bend and deform the vertical wall (referred to as a bending forming force F2), and a force required to change the diameter of the metal material outside the vertical wall (shrinkage). It is possible to suppress the application of the flange forming force F1).
Therefore, since the second annular groove can be formed by bending with a relatively small bending force F2, there is no risk of breakage during processing. Thereafter, similarly, the inner auxiliary punches are sequentially lowered one by one to form an annular groove including vertical walls one after another at positions facing the auxiliary punches.
Subsequently, in step (c), after the innermost auxiliary punch is returned, the forming punch is lowered and drawn until the vertical wall formed on the outer peripheral side of the forming die completely disappears. . Thereby, a bottomed container is shape | molded from the bottom side. By performing the drawing process little by little in this way, the drawing process is performed without exceeding the limit drawing ratio.
Subsequently, in the step (d), the outermost auxiliary punch capable of performing an auxiliary bending process on the metal material remaining at the outside of the forming die up to the previous step is lowered. To perform auxiliary bending. Thereafter, the steps (b) to (d) are repeated, and the same processing is repeated until all metal materials are drawn with a forming punch and a forming die, thereby completing the bottomed container.

  According to the present invention, when processing a bottomed container from a metal material, an annular groove is formed one after another by a multistage auxiliary punch and auxiliary die, and the vertical wall of the annular groove formed at that time is formed. Since the drawing process is gradually advanced within the range in which the vertical wall does not disappear, the metal material does not change in diameter while the vertical wall is deformed. It is possible to suppress the force required to do this. As a result, it is possible to avoid processing exceeding the limit drawing ratio, and it is possible to safely perform drawing without performing mold replacement work with only a mold attached to one press device. It becomes like this.

It is a schematic block diagram of the metal mold | die which is one Embodiment of this invention, and a metal container manufacturing apparatus using the same. It is A-A 'sectional drawing of FIG. It is B-B 'sectional drawing of FIG. It is a figure which shows a part of processing state by the metal container manufacturing apparatus of FIG. It is a figure which shows a part of processing state by the metal container manufacturing apparatus of FIG. It is a figure which shows a part of processing state by the metal container manufacturing apparatus of FIG. It is a figure which shows a part of processing state by the metal container manufacturing apparatus of FIG. It is a figure which shows a part of processing state by the metal container manufacturing apparatus of FIG. It is a figure which shows a part of processing state by the metal container manufacturing apparatus of FIG. It is a figure which shows a part of processing state by the metal container manufacturing apparatus of FIG. It is a figure which shows a part of processing state by the metal container manufacturing apparatus of FIG.

  Hereinafter, the metal mold | die of this invention and the metal container manufacturing method using the same are demonstrated using drawing. FIG. 1 is a schematic cross-sectional view showing the overall configuration of a metal container manufacturing press apparatus to which a mold according to an embodiment of the present invention is attached, FIG. 2 is a cross-sectional view taken along line AA ′, and FIG. It is sectional drawing.

In the press apparatus 10, a composite die 11 is installed on the lower side of the apparatus, and a composite punch 12 is attached to the upper side of the composite die 11 at a position facing it.
The composite punch 12 includes a cylindrical forming punch 21 disposed in the center and hollow cylindrical auxiliary punches 22, 23, and 24 disposed in multiple stages on the outside thereof. Among these, the molding punch 21 may be a hollow cylindrical shape or a solid cylindrical shape. If a hollow cylinder is used, the weight can be reduced, and if a solid cylinder is used, the shape of the bottom wall can be rounded or an arbitrary shape.
In this embodiment, the auxiliary punch has three stages, but the number of stages may be increased or decreased according to the diameter of the disk-shaped metal material M to be processed. Specifically, as the diameter of the metal material increases, the number of steps is increased so that processing that does not exceed the limit drawing ratio can be performed.

The composite die 11 includes a hollow cylindrical molding die 31 disposed on the lower outer side of the molding punch 21 and hollow cylindrical auxiliary dies 32, 33, and 34 disposed in multiple stages on the outer side thereof. The number of steps of the auxiliary die is adapted to the number of steps of the auxiliary punch described above.
The forming die 31 and the auxiliary dies 32, 33, and 34 are arranged so that the heights of the upper surfaces thereof are equalized, so that when the disk-shaped metal material M is set, it is supported by the respective dies. .

  In this embodiment, the forming die 31 and the auxiliary dies 32, 33, and 34 are fixed so as to be integrated, but are divided separately so that the gap distance between the die and the punch can be changed depending on the thickness of the metal material. You may make it attach.

As shown in the figure, the forming die 31, the forming punch 21, the auxiliary dies 32, 33, 34, and the auxiliary punches 22, 23, 24 are arranged coaxially with a common axis as the central axis, and They are arranged alternately. The molding punch 21 is inserted into the hollow of the molding die 31, and the auxiliary punches 22, 23, 24 are gently inserted between the molding die 31 or the auxiliary dies 31, 32, 33 adjacent to the inner side and the outer side. It is made to do. The diameter of each punch and each die can bend the metal material when inserted, but it is almost the same as the thickness of the metal material to prevent the plate thickness from being excessively stretched and thinned. Designed so that a slightly smaller gap is formed between the punch and the die.
Further, the end surface where each punch and each die abuts against the metal material is a curved surface, and a curved wall is formed on the metal material where the end surface abuts.

  The forming punch 21 and the auxiliary punches 22, 23, 24 are independently connected to the pistons 45 to 48 of the hydraulic cylinders 41 to 44, and the piston is adjusted by adjusting the amount of oil supplied into the hydraulic cylinder. Each punch is moved up and down by moving up and down.

  Moreover, since the length according to the depth of the bottomed container to manufacture is required for the shaping | molding punch 21, the length of the side wall is made longer than the other auxiliary punches 22-24. Similarly, also about the shaping | molding die 31, the side wall is made longer than the other auxiliary dies 32-34 according to the depth of the bottomed container to manufacture. In this embodiment, the auxiliary punches 22, 23, and 24 have the same length, and the auxiliary dies 32, 33, and 34 have the same length. May be increased toward the inside.

  The press device 10 is computer-controlled in the same manner as a normal press device, but as control parameters, the initial setting position of each punch, the pressing start position, the pressing start time, the pressing distance, the pressing end time, the pulling start time, the pulling distance, Numerical values can be set in advance for the withdrawal end time, stationary position, pushing speed, withdrawal speed, and pushing force. These numerical values are set so as to obtain optimum conditions through preliminary tests and trial and error before processing the product.

  Next, the container manufacturing method by the said press apparatus 10 is demonstrated. FIG. 4A to FIG. 4J are diagrams for sequentially explaining steps when manufacturing a bottomed container from a metal material (blank material). In the following drawings, for the sake of convenience, only the positional relationship between the composite die 11 (forming die 31, auxiliary dies 32, 33, 34), composite punch 12 (forming punch 21, auxiliary punches 22, 23, 24) and the metal material M is shown. Is shown.

First, as shown in FIG. 4A, the disk-shaped metal material M to be processed is placed on the forming die 31 and the auxiliary dies 32, 33 and 34. At this time, the metal material M is positioned so that the center of the metal material M coincides with the center axis of the punch and die.
Subsequently, as shown in FIG. 4B, the outermost auxiliary punch 22 is lowered, and between the auxiliary die 32 positioned outside the auxiliary punch 22 and the auxiliary die 33 positioned inside the auxiliary punch 22. By inserting, an annular groove G1 is formed.
At this time, a curved wall P1 is formed at a portion that contacts the end surface of the auxiliary punch 22, and a curved wall P2 is formed at a portion that contacts the end surface of the auxiliary die 33. Along with these, a vertical wall is formed between the curved wall P1 and the curved wall P2. The auxiliary punch 22 is sufficiently pushed so that T1 is formed. The vertical wall T <b> 1 is formed at a portion sandwiched between the side surface of the auxiliary punch 22 and the side surface of the auxiliary die 33.

  Subsequently, as shown in FIG. 4C, the auxiliary punch 22 is returned to the original position, the auxiliary punch 23 on the one inner side is lowered, the auxiliary die 33 located outside the auxiliary punch 23, and the auxiliary located on the inner side. By inserting between the dies 33, an annular groove G2 is formed. At this time, a part of the groove G1 formed in the previous step (see FIG. 4B) is deformed so as to be sequentially drawn toward the groove G2, but the vertical wall T1 does not disappear completely. The pushing depth of the auxiliary punch 23 (that is, the pushing length of the piston 47 in FIG. 1) is limited to the range.

  By limiting the pushing depth of the auxiliary punch 23 to this range, only the change in which the curved wall P1 moves upward from the bottom (the vertical wall T1 is contracted) occurs, and the radial deformation of the curved wall P1 occurs. Can not be. As a result, only the force required for bending deformation is applied to the metal material M when the groove G2 is formed, and when the curved wall P1 outside the vertical wall T1 starts to be drawn, Do not apply the large force required for shrinkage deformation. In this way, the problem that the metal material M is erroneously applied with a large force and is broken is eliminated.

  A vertical wall T2 is formed between the auxiliary punch 23 and the auxiliary die 33, a curved wall P3 is formed at a portion that contacts the end surface of the auxiliary punch 23, and a vertical wall is formed between the auxiliary punch 23 and the auxiliary die 34. T3 is formed, and the curved wall P4 is formed in the portion that contacts the end face of the auxiliary die 34. As a result, the groove G1 is deformed and floats from the original position.

Subsequently, as shown in FIG. 4D, the auxiliary punch 23 is returned to the original position, and the auxiliary punch 24 is lowered and inserted between the auxiliary die 34 and the forming die 31 to thereby form an annular groove G3. Form. At this time, a part of the groove G2 formed in the previous step (see FIG. 4C) is deformed so as to be sequentially drawn toward the groove G3, but the vertical wall T3 is not completely lost. Is limited to the pushing depth of the auxiliary punch 24 (that is, the pushing length of the piston 46 in FIG. 1).
As a result, only the force required for bending deformation is applied to the metal material M when the groove G3 is formed, and when the curved wall P3 outside the vertical wall T3 starts to be pulled in, a new force is applied. Do not apply the large force required for shrinkage deformation. In this way, the problem that the metal material M is erroneously applied with a large force and is broken is eliminated. A vertical wall T 4 is formed between the auxiliary punch 24 and the auxiliary die 34, a curved wall P 5 is formed at a portion that contacts the end face of the auxiliary punch 24, and the vertical wall is formed between the auxiliary punch 24 and the forming die 31. T5 is formed, and the curved wall P6 is formed in the portion that contacts the end face of the forming die. At this time, the grooves G1 and G2 are deformed and come to float.

Subsequently, as shown in FIG. 4 (e), the auxiliary punch 24 is returned to its original position, and the molding punch 21 is lowered and inserted inside the molding die 31. At this time, the bottom wall U0 of the container is formed. Further, by pushing the molding punch 21, the side wall U <b> 1 is formed.
At this time, the groove G3 formed in the previous step (see FIG. 4D) is deformed so as to be sequentially drawn toward the bottom wall U0 and the side wall U1, but the vertical wall T5 has completely disappeared. The push-in depth of the forming punch 21 is limited to the extent that it does not streak. Thereby, when the bottom wall U0 and the side wall U1 are formed, only the force required for bending deformation is applied to the metal material M, and the curved wall P5 outside the vertical wall T5 starts to be drawn. In addition, a large force required for shrinkage deformation to be newly applied is not applied. In this way, the problem that the metal material M is erroneously applied with a large force and is broken is eliminated.

  Through the above steps, a part of the bottomed container is formed, but a part of the metal material M that has been deformed into a corrugated shape still remains outside the forming die 31. In FIG. 4E, since the remaining portion of the metal material M exists up to the position between the auxiliary die 32 and the auxiliary die 33, the processing is continued from the auxiliary punch 22 thereafter.

  That is, as shown in FIG. 4 (f), the auxiliary punch 22 is lowered and inserted between the auxiliary die 32 and the auxiliary die 33, so that an annular groove G1 partially lacking is formed again. In this case, the curved wall P1 is shorter than that in FIG. 4B, but the vertical wall T1 is formed.

  Thereafter, the operation described with reference to FIGS. 4C to 4F is repeated several times, and the side wall U1 is extended little by little. At this time, the length of the vertical wall T5 becomes the upper limit of the length change of the side wall U1 per one time. Immediately before completion, as shown in FIG. 4G, the final machining of the vertical wall T5 by the auxiliary punch 24 is performed.

Subsequently, as shown in FIG. 4 (h), the auxiliary punch 24 is returned to the original position, and the forming punch 21 is lowered. Thereby, all the metal raw materials M are squeezed by the forming punch 21 and the forming die 31, and a desired bottomed container U2 is formed.
By the above procedure, when manufacturing a bottomed container from a disk-shaped metal material, it is possible to perform drawing without failing with a single press device.

(Other embodiment)
In the metal container manufacturing apparatus 10 described above, the auxiliary punches 22, 23, and 24 and the auxiliary dies 32, 33, and 34 have the same height, but the outer auxiliary punch 22 and the auxiliary die 32 become shallower and the inner side becomes closer. You may make it deep.
Thereby, since the formed annular groove can be made deeper toward the inner side, it can be processed efficiently.

  The present invention can be used when a bottomed container is manufactured from a disk-shaped metal material.

10: Metal container manufacturing apparatus 11: Compound die 12: Compound punch 21: Molding punch 22, 23, 24: Auxiliary punch 31: Molding die 32, 33, 34: Auxiliary die 41, 42, 43, 44: Hydraulic cylinder 45, 46, 47, 48: Pistons T1 to T5: Vertical walls P1 to P6: Curved walls

Claims (5)

A mold for producing a bottomed container from a disk-shaped metal material,
A cylindrical molding punch,
A hollow cylindrical forming die that is coaxially disposed opposite to the forming punch at a position below and outside the forming punch, and into which the forming punch can be inserted inside during processing.
The outer diameter of the molding die is larger than the outer diameter of the molding die, and is alternately and coaxially disposed at the outer position of the molding die and the outer position of the molding die, and is processed by the molding punch and the molding die. Comprising at least one hollow cylindrical auxiliary punch and at least one hollow cylindrical auxiliary die that are previously subjected to auxiliary bending;
The forming punch and the auxiliary punch are configured independently of each other so as to move up and down independently one by one,
The upper surface of the forming die and the upper surface of each auxiliary die are adjusted to the same height so as to simultaneously support the lower surface of the disk-shaped metal material,
Each auxiliary punch is inserted between an auxiliary die arranged opposite to the outer lower position of each auxiliary punch and an auxiliary die or a forming die arranged opposite to the inner lower position during processing, and the metal material includes a vertical wall. A mold characterized by forming an annular groove.   The mold according to claim 1, wherein the axial length of the forming die is longer than that of the auxiliary die.   The mold according to claim 1, wherein the molding die and each auxiliary die are fixed so as to be integrated.   The mold according to claim 1, wherein the molding die and each auxiliary die are separately divided and attached. A cylindrical forming punch, a hollow cylindrical forming die that is coaxially disposed opposite to the forming punch at a position below and outside the forming punch, and into which the forming punch can be inserted, and an outer diameter of the forming die At least one hollow cylindrical auxiliary punch and at least one hollow cylindrical shape that are larger in diameter and are alternately arranged coaxially and oppositely on the outer side of the molding punch and on the outer side of the molding die. And the upper surface of the forming die and the upper surface of each auxiliary die are adjusted to the same height so as to simultaneously support the lower surface of the disk-shaped metal material, The molding die and the auxiliary die are formed using a mold having a structure inserted between an auxiliary die arranged opposite to the outer position of the auxiliary punch and an auxiliary die or molding die arranged opposed to the inner position. A metal container manufacturing method for manufacturing the bottomed container from a circular plate-like metal material is placed on top of,
(A) Lowering the outermost auxiliary punch to perform an auxiliary bending process, and forming an annular groove including a vertical wall in a disk-shaped metal material,
(B) After returning the auxiliary punch lowered in the previous process, the auxiliary punch inside is lowered in a range where the vertical wall formed in the previous process does not disappear, and an auxiliary bending process is performed, and the vertical wall is included. Forming an annular groove, and thereafter performing the same lowering and returning to the inner auxiliary punch one by one, repeating until the innermost auxiliary punch is lowered,
(C) After the innermost auxiliary punch is returned, the bottomed container is formed from the bottom side by lowering the forming punch and performing drawing processing within a range in which the vertical wall formed on the outer peripheral side of the forming die does not disappear. The process of
(D) After the previous step, the metal material remaining outside the forming die is lowered by lowering the outermost auxiliary punch capable of performing auxiliary bending on the metal material at that time. Thereafter, the steps (b) to (c) are repeated, and a metal container manufacturing method for manufacturing a bottomed container so that all metal materials are drawn with a forming punch and a forming die.