JP2013220444A - Press forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a press forming method by which an edge caused by drilling is not in contact with a formed body so as to improve reliability.SOLUTION: In a press forming method which forms a formed article by holding the formed article arranged in between by an upper die and a lower die, the upper die and the lower die include a plurality of oil supply members arranged on a formed article side when the formed article is held. The upper die and the lower die include internal flow channels for flowing lubricant inside. When the lubricant flowing in the internal flow channels flows out to the formed article side through the oil supply members, the formed article, the upper die, and the lower die are lubricated.

Description

  The present invention relates to a press molding method, and more particularly to a structure for supplying a lubricating oil to a mold in forming a drawn shape.

  As background art of this technical field, there is JP-A-4-371323 (Patent Document 1). This publication states that “a lubrication nozzle made of the same material is embedded on the surface of a punch member of a draw mold, and the lubrication nozzle has a small diameter that does not cause deformation in the molded product during pressing. A number of outlets are perforated, and a necessary part of the surface of the punch member is lubricated by the lubricating oil discharged from these discharge ports.

JP-A-4-371323

  According to the said patent document, the hole for oil supply is made in the metal mold | die itself. The diameter of the hole is such that no deformation occurs in the molded product, but since it is a small diameter and deep hole processing, it is easily guessed that the mold manufacturing cost increases. In general, it is known that when the diameter in drilling is d and the depth is L, the tool is likely to be damaged when L / d ≧ 30. In order to achieve this, it is necessary to use an expensive dedicated tool that is difficult to break.

  Further, in the patent document, as shown in FIG. 2, when the lubricating oil discharge port 20 is formed in the mold member 19, a round hole is processed into a curved surface, so that the edge 21 generated by the drilling comes into contact with the object to be molded, Scratches may occur and it is considered difficult to realize.

  Accordingly, an object of the present invention is to provide a press molding method capable of improving the reliability without causing the edge formed by the above-described drilling to contact the workpiece.

In order to solve the above problems, for example, the configuration described in the claims is adopted.
The present application includes a plurality of means for solving the above-described problems. For example, “the molding is formed by sandwiching the molding placed between the upper mold and the lower mold. In the press molding method, the upper mold or the lower mold includes a plurality of oil supply materials disposed on the molding side when the molding is sandwiched, and the upper mold or the lower mold The mold has an internal flow path for flowing lubricating oil therein, and the lubricating oil that has flowed through the internal flow path flows out to the molded object side through the oil supply material, whereby the molded object. The upper mold and the lower mold are lubricated ”.

  ADVANTAGE OF THE INVENTION According to this invention, the edge by punching does not contact a to-be-molded body, and the press molding method which can improve reliability can be provided. Problems, configurations, and effects other than those described above will be clarified by the following description of embodiments.

It is a figure for demonstrating the state which sprays lubricating oil on a press metal mold | die using a nozzle. It is a figure explaining the lubricating oil discharge port of a prior art. It is an example of sectional drawing of the metal mold | die before a shaping | molding of a present Example, and a to-be-molded object. It is an example of sectional drawing of the metal mold | die after a shaping | molding of a present Example, and a to-be-molded object. It is an example of the structure which has arrange | positioned the oil supply material to the corner R which needs lubrication most. It is an example of an oil supply material. It is an example of the characteristic of an oil supply material. It is a figure which shows the attachment state of an oil supply material.

Embodiments of the present invention will be described below with reference to the drawings.
〔Example〕
FIG. 1 is a view for explaining a state in which lubricating oil is sprayed onto a press mold using a nozzle. The press machine shown in FIG. 1 includes a press die composed of an upper die 1 and a lower die 2, and an object to be molded is disposed between them, and is sandwiched between the upper die 1 and the lower die 2. A molded object is formed. The press machine includes a slide 3 of the press machine, a bolster 4, an upper mold base 5, a lower mold base 6, a die 7, a die holder 8, a plate retainer 9, a spring 10, a nozzle 11, an oil supply pipe 12 connected to a pump, an oil A supply pipe fixing portion 13 is provided.

  In general, drawing with a press die, especially when the shape after molding is complex, the metal plate, which is the molded body, is cracked and cracked, and the die wears over time. Problems arise. In order to prevent these phenomena, in FIG. 1, the lubricating oil 14 is sprayed from the nozzle 11 installed outside the mold toward the mold surface to reduce the frictional force between the workpiece and the mold. Among the press molds, in the drawing mold for forming irregularities, the reaction force accompanying the molding is applied to the corner R15 portion at the time of molding. Therefore, in order to improve the moldability, the lubricating oil 14 is applied to the corner R15 portion. Is required.

  However, the tension balance at the time of molding due to the interference between the workpiece (molded body) on the nozzle 11 during the movement between the upper mold 1 and the lower mold 2 and the adhesion of lubricant to the die holder 8 of the blank material. Non-uniformity occurs. Furthermore, since the lubricating oil scatters to other than the target portion, the working environment is deteriorated due to the waste of the lubricating oil and the floating oil droplets. Further, when the spray to the corner R15 of the recess or the spray distance is long, there is a problem that the lubricating oil cannot be applied to the target portion. In FIG. 1, reference numeral 16 denotes a portion where the lubricating oil cannot be applied, and reference numeral 17 denotes a portion where the lubricating oil is applied wastefully. Therefore, the configuration of this embodiment for solving these problems will be described below.

  3 and 4 are diagrams showing the configuration of the press die of the present embodiment, and the procedure of the press die will be described using these.

  FIG. 3 is a cross-sectional view of the mold and the molding before molding, and FIG. 4 is a cross-sectional view of the mold and the molding after molding. First, as shown in FIG. 3, a thin sheet metal (generally 0.5) is formed between the upper upper mold 1 and the lower mold 2 disposed below the upper mold 1. ~ 6t). Thereafter, as shown in FIG. 4, the molding 22 is molded into a desired shape by sandwiching the molding 22 between the upper mold 1 and the lower mold 2. Here, in this embodiment, an internal flow path 23 for supplying lubricating oil to the upper mold 1 and the lower mold 2 is provided, and a discharge port for supplying oil from the flow path to a target location. Is formed using an oil supply 24.

  The internal flow path 23 is connected to a pumping device (for example, a positive displacement pump 18) (not shown in FIG. 3 and FIG. 4) for supplying oil, and is linked to the stroke of the mold by interlocking with the press machine. And it has the mechanism of discharging once at the top and bottom of one time. In addition, an electromagnetic valve is set between the positive displacement pump 18 and the oil supply member 24 to electrically open and close the oil filler opening. It is desirable that the internal flow path 23 has a size that can be processed with a general-purpose cutting tool in consideration of workability.

  The oil supply member 24 has a cylindrical shape in consideration of moldability, and a porous resin (for example, urethane foam) is used as the material. Alternatively, a sintered metal having an opening ratio of 5 to 80% can be used. At this time, it is needless to say that not only a cylindrical shape but also a shape such as a prism can be used depending on the shape of the mold. In the case of a porous material, the tolerance of the diameter of the oil supply material is -0.1 to 0 mm and the tolerance of the installation hole is +0.1 to +0.0. In the case of 2 mm and sintered metal, the tolerance of the diameter of the oil supply material is processed to ± 0.01 mm, and the tolerance of the installation hole is processed to +0.01 to +0.03 mm.

  A structure in which the oil supply material 24 is arranged at the corner R (15) that needs the most lubrication will be described with reference to FIG. The material of the oil supply material 24 is a sintered metal, and a material is selected that ensures rigidity to such an extent that the oil supply material will not be deformed or damaged even if the oil supply material itself is molded. By assembling the sintered metal into the mold and then processing the shape of the mold, it is possible to apply the lubricating oil to the corner R (15) that requires the most lubrication, and at the same time, realize a structure for molding the object to be molded.

  As described above, the press molding method of the present embodiment is to mold the molding 22 by sandwiching the molding 22 disposed between the upper mold 1 and the lower mold 2. The upper mold 1 or the lower mold 2 includes a plurality of oil supply materials 24 arranged on the molding object side when the molding object 22 is sandwiched, and the upper mold 1 or the lower mold 2 includes An internal flow path 23 for flowing lubricating oil is formed inside, and the lubricating oil that has flowed through the internal flow path 23 flows out to the molded object side through the oil supply material 24, whereby the molded object 22, Lubrication of the mold 1 and the lower mold 2 is performed.

  The oil supply material 24 is a porous resin in which a large number of through-holes are formed, and the lubricating oil that has flowed through the internal flow path 23 flows out to the molding object side through the oil supply material 24, thereby 22. It is desirable to lubricate the upper mold 1 and the lower mold 2. Alternatively, the material of the oil supply material 24 is a sintered metal, and the oil supply material 24 is disposed at a location to be a corner portion (corner R (15)) of the upper mold 1 or the lower mold 2 as described above. It becomes possible to shape | mold the to-be-molded product 22. In addition, after assembling the oil supply material 24, which is a sintered metal, to the upper mold 1 or the lower mold 2, the shape of the corner portion (corner R (15)) of the upper mold 1 or the lower mold 2 is processed. Desirably, the oil supply material 24 is used to apply lubricating oil and to form the molded body 22.

  By arranging the lubricating oil supply path in the mold itself in this way, it is possible to supply the required amount of lubricating oil only to the contact part between the workpiece and the mold, so that cracks and cracks in the molded object occur. And mold wear can be prevented. Further, it is possible to suppress the deterioration of the working environment and the waste of the lubricating oil caused by the scattering of the lubricating oil outside the mold. Further, it is possible to suppress scratches on the molded body due to the edge of the lubricating oil discharge port.

  Next, the dimensions of the oil supply member 24 will be described with reference to FIG. (A) is a cylindrical shape with a diameter d1 and a height h1. Thus, the oil supply material 24 is arranged in parallel to the surface on the molding object side, so that it is not necessary to process the oil supply material 24 into a complicated shape in accordance with the upper mold and the lower mold. (B) is the height h2 of (a) (h1-0.5, in this case, 0.5 mm in consideration of the surface tension of the oil). By forming a gap in the gap, lubricating oil can be held in the gap.

  FIG. 6 (c) shows an oil sump groove (chamfered at a diameter larger than the oil droplet diameter) around (a), and FIG. 6 (d) shows a hole of φd2 and depth i on the upper surface of (a). It is added. (C) and (d), as in (b), in order to allow the lubricating oil to be stored in the gap between the oil supply member 24 and the molding object of the mold, It is a cut structure. That is, in FIG. 6C, the oil supply member 24 is formed in a cylindrical shape, and the oil supply member 24 forms an oil reservoir groove along the outer periphery of the molding side surface. In FIG. 6D, the oil supply member 24 forms a hole at the center of the side surface of the molding. In this way, the oil supply material 24 is disposed on the same plane as the side surface of the molding object of the upper mold 1 or the lower mold 2 or on the opposite side of the molding object side through the clearance, so that the gap is formed. Lubricating oil can be retained.

  The characteristics of the oil supply material will be described with reference to FIG. FIG. 7 shows a state in which the oil supply material is assembled in the mold. In (b), (c), and (d) in which a part of the oil supply material is cut to supply oil, the oil discharged to the groove formed by the mold surface and the supply material is held without flowing out. The structure is such that oil does not come out in unnecessary parts.

  A method of attaching the oil supply material will be described with reference to FIG. Normally, the oil supply material is attached as shown in (a). However, in order to prevent the oil supply material from falling off during refueling, the shape of the oil supply material is provided with a flange as shown in (e). In some cases, a structure that is tightened with is used. In addition, this invention is not limited to an above-described Example, Various modifications are included. For example, the above-described embodiments have been described in detail in order to explain the present invention in an easy-to-understand manner, and are not necessarily limited to those having all the configurations described.

1 Upper mold 2 Lower mold 3 Slide 4 Bolster 5 Upper mold base 6 Lower mold base 7 Die 8 Die holder 9 Plate holder 10 Spring 11 Nozzle 12 Oil supply pipe 13 connected to the pump 13 Oil supply pipe fixing part 14 Lubricating oil 15 Corner R
16 Portion where lubricant cannot be applied 17 Portion where waste lubricant is applied 18 Positive displacement pump 19 Mold member 20 Lubricant discharge port 21 Edge 22 formed by drilling molding 23 Inside of lubricant connected to pump Flow path 24 Oil supply material 25 Direction of material extension 26 Oil reservoir 27 Bolt

Claims (8)

In a press molding method of molding the molding by sandwiching the molding arranged between the upper mold and the lower mold,
The upper mold or the lower mold includes a plurality of oil supply materials arranged on the molding side when the molding is sandwiched,
The upper mold or the lower mold is formed with an internal flow path for flowing lubricating oil therein, and the lubricating oil that has flowed through the internal flow path passes through the oil supply material to the molding object side. A press molding method characterized by lubricating the workpiece, the upper mold, and the lower mold by flowing out. In the press molding method according to claim 1,
The oil supply material is a porous resin in which a large number of through-holes are formed, and the lubricating oil that has flowed through the internal flow channel flows out to the molding object side through the oil supply material, whereby the molded product The press molding method characterized in that the upper mold and the lower mold are lubricated. In the press molding method according to claim 1,
The material of the oil supply material is a sintered metal, and the oil supply material is disposed at a location that becomes a corner portion of the upper mold or the lower mold. In the press molding method according to claim 3,
A press molding method, wherein the shape of the corner portion of the upper mold or the lower mold is processed after the oil supply material, which is the sintered metal, is assembled to the upper mold or the lower mold. In the press molding method according to claim 3,
A press molding method characterized by applying lubricating oil by the oil supply material which is the sintered metal and molding the object to be molded. In the press molding method according to claim 1,
The said oil supply material is comprised by the column shape, and this oil supply material forms the groove | channel for oil pools along the outer periphery of the said to-be-molded material side, The press molding method characterized by the above-mentioned. In the press molding method according to claim 1,
The said oil supply material forms a hole in the center part of the said to-be-molded object side surface, The press molding method characterized by the above-mentioned. In the press molding method according to claim 1,
A press molding method, wherein the oil supply material is disposed on the same plane as the side surface of the molding object of the upper mold or the lower mold or on the opposite side of the molding object side via a gap.