JP2015157465A - Injection molding device degassing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stably supply exhaust air means for an air exhauster with the highest effect by applying proper cutting work to an object to be cut.SOLUTION: A degassing device in an injection molding device, rapidly exhausting gas in a runner and a cavity to outside a machine is obtained by: installing a dent with about 4 mm width and about 2 mm depth on a head of an ejection pin or plug with about 12-16 mm diameter or part of a metal mold, with a standard that a cutting angle is 45 degrees and a ratio of a cutting part is width 2 : depth 1, for exhaust air means of the injection molding device decompressing compressed gas by passing through an extremely narrow passage, and guiding gas in a subsequent machine to the outside the machine by the decompression effect; conducting an opening with a width and height of about 0.2 mm into an exhaust air path from part of the dent; and installing a large number of combinations of the dent and the opening.

Description

      The present invention relates to a gas venting device in an injection molding apparatus.

      The present inventor has so far conducted research and development of venting to quickly and surely discharge the gas generated inside the runner and cavity of the injection molding machine and apply them to many work sites. Improvements have been made. Some of them are specified in the prior art document column.

Patent No. 4085182 Patent No. 4096327 Japanese Patent No. 5431780

      In the past, the generation of gas from high-temperature and high-pressure injection materials and the fact that the runner part and cavity part in the mold of the injection molding machine are filled with air have a great effect on the degree of product completion by injection molding. Although it has been confirmed that there is an effect, there is no effective means for exhausting those gases and intake air to the outside of the aircraft, and in order to solve such a problem, the present inventor The present invention has been completed.

    The principle for exhaustion shown in these inventions is that the pressurized gas is depressurized by passing through an extremely narrow passage, and the subsequent gas inside the fuselage is further guided to the outside by the depressurizing effect. Then, a recess having a diameter of about 4 mm and a depth of about 2 mm is drilled in the head of a protruding pin or plug having a diameter of about 12 to 16 mm, and an opening having a width and a height of about 0.2 mm is formed outside the part of the recess. By connecting a number of combinations of such depressions and openings, the gas inside the runner and the cavity is rapidly exhausted outside the apparatus.

      Exhaust by the combination of depression and passage shows unprecedented effectiveness, so the specific design of how to install these exhaust means in the mold has been repeatedly improved at the work site However, the problem of what hollow shape is more effective has been shelved without being pursued.

      The above-mentioned prior art is widely used in field work, so even if precise measurement is difficult, a large amount of empirical data can be accumulated, and for the purpose of organizing them and obtaining a more effective exhaust system The present invention has been made.

      From the experimental results and empirical rules so far, when manufacturing a gas venting device by cutting the edges of parts such as plugs, pins, and pieces in injection molding, the cutting angle and the width and depth of the cutting part are constant. The inventors of the present invention who have focused on the fact that the efficiency is very high although it is within the range of the results of categorizing and arranging those test results, the angle of cutting is 45 degrees to the edge of the object to be cut such as pins, plugs, and pieces The best results were obtained when cutting to a regular polygonal cone or a regular cone having a depth of 1 with respect to the width of 2.

      Since the best results are obtained when the conditions of cutting angle 45 degrees and cutting shape width 2: depth 1 are satisfied, it is concluded that this condition is the optimum processing shape of the degassing device in injection molding. The degassing apparatus according to the present invention is applied to various workpieces.

      According to the present invention, since it is possible to perform processing in accordance with the optimum conditions, it is possible to obtain a degassing device that always works reliably regardless of the material, shape, and volume of the workpiece, and molding in injection molding. This has the effect of improving the quality of the product and greatly extending the maintenance interval of the injection molding machine.

      FIG. 3 is a perspective view of a plug machined using a regular quadrangular pyramid according to the present invention.       It is sectional drawing of the conceptual diagram which shows the use condition of FIG.       It is a conceptual diagram of the cutting part for making the plug of FIG.       FIG. 4 is a perspective view of a plug machined using a regular cone shape according to the present invention.       It is a conceptual diagram of the cutting part for making the plug of FIG.       FIG. 3 is a perspective view of a pin machined using a regular quadrangular pyramid according to the present invention.       It is a conceptual diagram of the cutting part for making the pin of FIG.       FIG. 3 is a perspective view of a mold that has been subjected to a plurality of cutting operations using a regular quadrangular pyramid according to the present invention.       FIG. 6 is a perspective view of a discarded piece formed using the mold of FIG. 7 and the pin of FIG. 5.

      According to the standard that the present inventors have reached, a cutting angle of 45 degrees, a cutting part shape width: a depth of 2: 1, the edges of various workpieces 1 are cut, and the opening 3 continuous to the cutting part 2 is formed. Connected to the exhaust passage 4 that continues outside the machine.

      In the first embodiment shown in FIG. 1, a cutting part 2 that is a half of a regular quadrangular pyramid obtained by FIG. 2 is provided on a cuboid body 1 to be cut, and an exhaust passage 4 provided with the cutting part 2 and the body 1 to be cut. Are connected by an opening 3 drilled at the apex of a regular quadrangular pyramid.

      For simplicity of explanation, FIG. 2 shows a state in which a half regular quadrangular pyramid is inscribed in a quarter spherical surface, but this is a regular quadrangular pyramid inscribed in a hemisphere and sharing a vertex and a bottom surface. , Which proves that the ratio of width to depth of the cutting part 2 is 2: 1.

      In FIG. 2, A · X · B is the diameter of the sphere, and C · X is the radius of the sphere, so the proportionality is 2: 1, and A · X · B · D that matches one surface of the workpiece 1 The angle formed between the side surface and one side DC of the cutting portion 2 is 45 degrees.

      3 and 4 are exactly the same as those shown in FIG. 1 except that the shape of the cutting part 2 is determined according to a regular quadrangular pyramid. Cutting is performed using a regular cone instead of a regular quadrangular pyramid. The shape of part 2 is arranged. In this case as well, the proportion of dimensions is exactly the same as that shown in FIG.

      FIG. 5 is a perspective view of the cutting portion 2 formed by cutting the bottom edge of the cylindrical pin 5, and the outer peripheral surface rising from the cylindrical bottom surface is bent. Both wings are slightly shorter than the example shown in FIG. 1, but the ratio of width to depth can be considered to be approximately 2: 1 as shown in FIG.

      FIG. 7 shows a plurality of cutting parts 2 according to the present invention arranged side by side on a part of a mold 6. By combining such a mold 6 and the pin 5 shown in FIG. 5, the small volume shown in FIG. A discarded piece 7 can be formed, whereby a large amount of exhaust can be performed. The throwing piece 7 is formed by installing a small sub mold separately from the main mold of the injection molding apparatus, the former for product molding, and the latter for exhaust of the main mold. It is used at the same time as a means to assist.

      According to the present invention, since the cutting portion having the highest exhaust effect can be accurately installed in any case, a more stable and more effective exhaust device can be obtained regardless of the injection material. Highly accurate injection molded products can be manufactured in all injection molding apparatuses and die casting apparatuses.

DESCRIPTION OF SYMBOLS 1 ... To-be-cut body 2 ... Cutting part 3 ... Opening part 4 ... Exhaust passage 5 ... Pin 6 ... Mold 7 ... Discarding piece

      FIG. 3 is a perspective view of a plug machined using a regular quadrangular pyramid according to the present invention.       It is a perspective view showing the concept for manufacturing the Example of FIG.       FIG. 4 is a perspective view of a plug machined using a regular cone shape according to the present invention.       It is a perspective view showing the concept for manufacturing the Example of FIG.       FIG. 3 is a perspective view of a pin machined using a regular quadrangular pyramid according to the present invention.       It is a slope figure showing the concept for manufacturing the Example of FIG.       FIG. 3 is a perspective view of a mold that has been subjected to a plurality of cutting operations using a regular quadrangular pyramid according to the present invention.       FIG. 6 is a perspective view of a discarded piece formed using the mold of FIG. 7 and the pin of FIG. 5.

Claims (1)

Assuming an axis extending through the center of the base circle from the vertex of the half sphere at an angle perpendicular to the virtual half sphere base circle,
A vertex of a virtual regular polygonal cone or regular cone inscribed in the half sphere is positioned at the vertex of the half spherical shape, and the bottom of the regular polygonal cone or regular cone is made coincident with the bottom of the half spherical shape; The half sphere is divided into two by the plane of the object to be cut passing through the axis or the curved surface having a constant curvature, and the surface perpendicular to the plane of the object to be cut or the constant curvature is made to coincide with the bottom surface of the half sphere. In the state, the inside of the regular polygonal cone or the regular cone virtually drawn on the workpiece is cut and removed, and the cut portion of the workpiece generated by the removal is connected to the outside of the injection molding machine. A gas venting device in an injection molding apparatus, wherein an opening passing through a half spherical apex is formed.

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