JP2010284727A - Punching die of plastic sheet molded product - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To disclose a punching die adapted to prevent deflection of movable protruding blades and vibration of stationary recessed blades, or the like, so that both always accurately mesh with each other, thereby stably supplying a high-quality plastic sheet molded product. <P>SOLUTION: The punching die includes the liftably supported movable protruding blades; and the stationary recessed blades having an internal shape to permit insertion of blade edges of these movable protruding blades. In each movable protruding blade, a blade edge part insertable into the stationary recessed blade is protrudingly disposed at a lower edge of an enlarged barrel having an external shape larger than the internal shape of the stationary recessed blade. The movable protruding blades have in the interior thereof an escape recess for a molded part of the plastic sheet molded product. The stationary recess blades are shaped like boxes where the interior of a die frame is divided for each movable protruding blade by partition portions. The die frame and the partition portions are bolt-fixed to a base. In the stationary recessed blades, the die frame and the partition portions are soldered or welded to the base along their internal shape. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a punching die for a plastic sheet molded product, and relates to a configuration in which a movable convex blade and a fixed concave blade are accurately meshed with each other.

  Plastic sheet molded products typified by food containers and trays are produced by punching molded sheets, such as vacuum forming, for each molded product in the final process, but the punching die consists of a movable convex blade and a fixed concave blade. (See Patent Documents 1 to 3).

  FIG. 3 is a conventional punching die that generalizes the configuration disclosed in Patent Documents 1 to 3, and a molded sheet 11 conveyed with the concave molded portion 10 facing upward is fixed to the fixed concave blade 12. The molding sheet 11 is punched out by stopping at a predetermined position on the upper surface and lowering the movable convex blade 13 from above to insert the blade edge 13a into the fixed concave blade 12. That is, the periphery of the molded portion of the molded sheet is sheared by the engagement of the outer periphery of the movable convex blade 13 with the inner periphery of the fixed concave blade 12. An escape recess 13b is formed in the movable convex blade 13 so that the molded portion 10 of the molded sheet 11 does not interfere when punching, while a discharge hole 12a is vertically formed in the fixed concave blade 12, and this discharge is performed. The molded product after being punched from the hole 12a is dropped and collected.

Japanese Patent Laid-Open No. 63-47098 (refer to FIGS. 8 and 9 in particular) Japanese Patent Laying-Open No. 2001-71298 (see particularly FIG. 11) JP 2002-172593 A (refer to FIG. 6 in particular)

  The present invention also punches a plastic sheet molded article by meshing a movable convex blade and a fixed concave blade, and its final object is to prevent debris and burrs from being generated during the punching. That is, when the movable convex blade and the fixed concave blade are not accurately meshed with each other, burrs, whiskers, and the like are generated in the punched residue and the molded product. Conventionally, as apparent from FIG. 3, the outer shape of the movable convex blade 13 is the cutting edge. Since the inner shape of the fixed concave blade 12 is the same as the inner shape of the fixed concave blade 12 from 13a to the substantially upper surface position of the relief concave portion 13b, this portion is thin and long and the support strength of the blade edge 13a is not so high. There is a case where it does not mesh with the fixed concave blade 12 by bending to the left and right. In particular, in order to obtain a molded product having a deep bottom, when the escape recess 13b of the movable protrusion 13 is also deep, the bending of the cutting edge 13a is more remarkable.

  In addition, as shown in FIG. 4, the conventional fixed concave blade 12 is bolted only to the fixing step 12b formed around the fixed concave blade 12 to the base 14, so that the entire fixed concave blade is fixed to the base 14 with uniform strength. The inner side (discharge hole side) of the fixed concave blade 12 slightly lifted or vibrated from the pedestal 14 during punching, and it was difficult to expect accurate engagement with the movable convex blade 13.

  As described above, the conventional punching die is liable to generate debris, burrs and the like in the plastic sheet molded product due to inaccurate engagement of the movable convex blade 13 and the fixed concave blade 12, and such foreign matter remains attached to the molded product. In many cases, the product is returned without satisfying the quality standards on the user side, not only the yield is poor, but also when the molded product is a container or tray for food, the foreign matter may be mixed into the food.

  In order to avoid such problems, in the past, the punching dies were frequently inspected and adjusted, but each time the line had to be stopped, there was another problem that productivity deteriorated due to a decline in operating rate. .

  The present invention has been made in view of the above-mentioned problems, and the object of the present invention is to prevent the bending of the movable convex blade, the vibration of the fixed concave blade, etc., so that the two are accurately meshed at all times, and the high quality is achieved. It is to disclose a punching die capable of stably supplying a plastic sheet molded article.

  In order to achieve the above-described object, the present invention is a punching die comprising a movable convex blade supported so as to be movable up and down, and an inner fixed concave blade into which the cutting edge of the movable convex blade can be fitted, The blade used means that a blade edge portion that can be fitted into the fixed concave blade protrudes from the lower edge of the enlarged body having an outer shape larger than the inner shape of the fixed concave blade. According to the said means, a blade edge | tip part will be supported by an expansion trunk | drum, and the bending of a blade edge | tip part is prevented at the time of punching.

  In addition, the raising / lowering operation of the movable convex blade is naturally performed within a range in which the molded sheet to be punched can be sheared, and the molded sheet to be punched may be flat. When targeting a molded product having a concave molded part such as a container, the movable convex blade can be moved up and down without interfering with the molded part by providing a relief concave part of the molded part inside the movable convex blade. It can be operated.

  On the other hand, the fixed concave blade can adopt the same structure as the conventional one as long as the cutting edge portion of the movable convex blade can be inserted, but more preferably, the inside of the mold part is provided for each movable convex blade. A bowl-like shape partitioned by a partition portion is formed, and the mold frame portion and the partition portion are bolted to a base. According to this means, the entire fixed concave blade is firmly fixed to the pedestal, and partial lifting of the fixed concave blade is prevented.

  Furthermore, the fixing strength of the inner shape part, which is the most important part of the fixed concave blade, is increased by integrally joining the mold part and the partition part to the base by brazing or welding along the internal shape of the fixed concave blade. Thus, it is possible to prevent the fixed concave blade from rising and vibrating more reliably.

  Moreover, by hardening the movable convex blade and the fixed concave blade, the hardness of the blade is increased, high shearing force is obtained, and durability such as wear resistance is also increased.

  Furthermore, a scraper having a predetermined thickness that comes into contact with the cutting edge portion is provided at the rising position of the movable convex blade, and the amount of protrusion of the cutting edge portion from the enlarged body is made 4 to 6 mm larger than the thickness of the scraper. Thus, the scrap removal effect by the scrap collector can be obtained while preventing the cutting edge portion from being bent at the time of punching.

  According to the present invention, since the cutting edge portion of the movable convex blade is supported in a state in which bending and vibration are suppressed by the enlarged body portion, the movable convex blade accurately meshes with the fixed concave blade, and there is no punching residue, burrs, and whiskers. A plastic sheet molded product with high quality and high accuracy can be obtained. In addition, because the movable convex blade is provided with a relief recess in the molded part, it can be applied not only to flat molded products but also to containers and cup-shaped molded products. We were able to. Furthermore, since the fixing strength of the fixed concave blade with respect to the pedestal is increased, there is no vibration or bending on the fixed concave blade side, and more accurate meshing is possible. As a result, as an example, according to the present invention, when the punching operation is performed under exactly the same conditions as the blades need to be adjusted about 5 to 10 times a day in the prior art, 15 to 20 days according to the present invention. There was no need to adjust the blade at all, and a high-quality and high-precision plastic sheet molded product could be obtained stably.

The partial cross section side view of the punching die which concerns on one Embodiment of this invention Plan view of fixed concave blade in the same embodiment Partial sectional side view of a conventional punching die A plan view of a fixed concave blade in a conventional punching die

  Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a partial cross-sectional side view of a punching die according to an embodiment of the present invention, in which 1 is a movable convex blade, 2 is a base on which a plurality of movable convex blades 1 are fixed, and 3 is a movable convex blade. The fixed concave blade 4 corresponding to 1 is a base on which a plurality of fixed concave blades 3 are fixed. The plurality of movable convex blades 1... 1 fixed to the pedestal 2 are moved up and down simultaneously as a group by a lifting device (not shown). Further, the plastic sheet molded product to be punched is conveyed between the movable convex blade 1 and the fixed concave blade 3 with the molding portion S1 of the molded sheet S before punching upward, and after positioning appropriately, the movable convex A punching operation is performed by lowering the blade 1, and a pedestal 4 is formed with a molded product discharge hole 4a communicating with the inner shape 3a and penetrating vertically. The basic configuration and operation so far are the same as those of the conventional technology.

  Therefore, the features of the present invention will be described. First, the movable convex blade 1 is inserted into the inner shape 3a of the fixed concave blade 3 at the lower edge of the enlarged body 1a having an outer shape larger than the inner shape 3a of the fixed concave blade 3. The possible blade edge portion 1b is provided so as to protrude. That is, as compared with FIG. 3 showing the prior art, the movable convex blade 1 according to the present invention has a thicker body and a shorter cutting edge than the conventional one. Therefore, the blade edge portion 1b is not easily bent or vibrated, and accurately meshes with the fixed concave blade 3. Furthermore, it is preferable to employ quenching for both the movable convex blade 1 and the fixed concave blade 3 from the viewpoint of achieving both shearing ability and durability.

  In this embodiment, in order to obtain a molded product of the container, the inside of the movable convex blade 1 is hollowed out to form the relief concave portion 1c of the molded portion of the container. However, the strength of the blade edge portion 1b is nevertheless. Is high, and bending at the time of punching is prevented. However, when the punching target is a smooth sheet, the relief recess 1c can be omitted.

  On the other hand, in this embodiment, the fixed concave blade 3 is also characterized. That is, as shown in FIG. 2, each of the fixed concave blades 3... 3 has a hook shape in which the interior of the rectangular mold part 3 a is partitioned by the partition part 3 b, and the mold part 3 b and the pedestal 4. Both of the partition portions 3 c are fixed with bolts 5. For this reason, the attachment strength with respect to a base becomes higher than the conventional fixed concave blade which bolted only the mold side (step part), and it is prevented that the fixed concave blade 3 partially lifts or vibrates. . Accordingly, in combination with the thick movable convex blade 1, more accurate meshing is possible, and the occurrence of punch debris, burrs, whiskers, and the like is suppressed. However, the number of bolts 5 and the fixing points are not limited to those illustrated.

  Furthermore, in this embodiment, along the inner side (inner shape 3a of the fixed concave blade 3), the mold part 3b and the partition part 3c are brazed or welded to the base 4 to form the metal joint part 6. 2 (shaded portion in FIG. 2), the fixing strength of the fixed concave blade 3 with respect to the base 4 is further increased, and the above-described lifting and vibration are almost completely eliminated.

  Furthermore, in this embodiment, the scraper 7 having a predetermined thickness is provided on the base 2 of the movable convex blade 1. This waste catcher 7 itself has a known configuration adopted in a conventional punching die, and removes waste by contacting the cutting edge portion 1b of the movable convex blade 1 that rises after punching. In order to satisfy both of the scrap removal function and the above-described bending prevention function of the blade edge portion 1b, the protruding amount of the blade edge portion 1b from the enlarged body portion 1a may be made larger by about 5 mm than the thickness of the scraper 7. Preferably, this numerical value can be changed within a range of 4 to 6 mm.

  According to the above embodiment, there is no generation of scum (kona), burrs, and mustaches, and naturally there is no need to remove them, and high-quality plastic sheet molded products can be stably supplied with high productivity. It was. Moreover, in addition to the fact that both the movable convex blade 1 and the fixed concave blade 3 are free from bending and vibration, and the hardness is increased by quenching, the life of these blades is 3-5 times that of the prior art. Of course, the number of movable convex blades 1 and fixed concave blades 3 and the arrangement when a plurality of movable concave blades 3 are provided are not limited to those of the present embodiment.

DESCRIPTION OF SYMBOLS 1 Movable convex blade 1a Enlarged trunk | drum 1b Cutting edge part 3 Fixed concave blade 3a Inner shape 3b Formwork part 3c Partition part 2, 4 Upper and lower pedestal 5 Bolt 6 Metal junction part 7 Scraper

Claims (6)

A punching die comprising a movable convex blade supported so as to be movable up and down, and an inner fixed concave blade into which the cutting edge of the movable convex blade can be inserted, wherein the movable convex blade is more than the inner shape of the fixed concave blade. A punching die for a plastic sheet molded product, characterized in that a cutting edge portion that can be fitted into the fixed concave blade protrudes from a lower edge of an enlarged body portion having a large outer shape. 2. The punching die for a plastic sheet molded product according to claim 1, wherein the movable convex blade has a relief recess of a molded part of the plastic sheet molded product inside. The plastic sheet molding according to claim 1 or 2, wherein the fixed concave blade has a bowl shape in which the inside of the mold part is partitioned by a partition part for each movable convex blade, and the mold part and the partition part are bolted to a base. Product punching die. 4. The punching die for a plastic sheet molded product according to claim 3, wherein the fixed concave blade is further integrally joined with the pedestal along the inner shape of the fixed frame and the partition. The punching die for a plastic sheet molded product according to any one of claims 1 to 4, wherein the movable convex blade and the fixed concave blade are quenched. A dipping machine having a predetermined thickness that comes into contact with the cutting edge at the rising position of the movable convex blade, and the amount of protrusion of the cutting edge from the enlarged body is 4 to 6 mm larger than the thickness of the cutting board. A punching die for a plastic sheet molded product according to any one of 1 to 5.

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