JP5285482B2 - Resin mold - Google Patents

Description

  The present invention relates to a resin mold, and more particularly to a mold structure used for molding a molded product with a drainage portion having a stepped shape.

  In the conventional drainage structure of a wash bowl, the drain tube is dropped from above into a drain port provided at the bottom of the wash bowl, and the drain tube is attached to the drain port by tightening a nut from below. However, in this drainage structure, the boundary between the upper flange part of the drainage cylinder and the wash bowl is exposed on the inner face side of the wash bowl, and dust tends to collect. Need to do.

  Then, the structure which attaches a drain pipe from the downward direction of a wash bowl is known (for example, refer patent document 1). In this conventional example, the drain tube is not exposed to the inner surface side of the wash bowl, and the above problem is improved.

  However, in this patent document 1, since the drain tube is fixed by the mounting screw on the lower surface side of the wash bowl, it is difficult to fix the drain tube in close contact with the lower surface of the wash bowl. There is a problem that leakage is likely to occur.

JP 2002-266403 A

  Therefore, in order to solve the above-mentioned conventional problems, the present inventors have already filed Japanese Patent Application No. 2008-217403, and as shown in FIG. 5, the drain port portion that protrudes downward from the bottom portion of the wash bowl 1. 2, the lower end of the inner peripheral surface of the drain port 2 is recessed outward to form a fitting recess 4 into which the drain tube 5 is fitted from below, and the inner peripheral surface of the drain port 2 Has already disclosed a wash bowl 1 having a stepped drainage port 2 with the upper end of the cover being a cover 3 covering the upper side of the drainage cylinder 5 and a resin molding die shown in FIG. .

  The resin molding die shown in FIG. 6 is configured by inserting a holder 20 between an upper die 31 and a lower die 32. In the figure, 21 is a positioning convex portion, 33 is a release air discharge hole, 34 is a mounting nut, 35 is a vent pipe, arrow b is a resin material injecting direction, arrow c is an air vent direction, and arrow d is a mold release. Air supply direction for each is shown.

  A concave groove 52 for inserting an O-ring 51 that constitutes a ring-shaped elastic body is provided in the upper end surface 20a of the holder 20. The concave grooves 52 are provided at four locations as shown in FIG. 7, for example. The depth of each concave groove 52 is formed to be shallower than the thickness of the O-ring 51, whereby the O-ring 51 protrudes upward from the upper end surface 20 a of the holder 20, and the O-ring 51 protrudes during mold clamping. The air vent gap S is formed in a state in which the portion is elastically deformed by being pressed by the lower surface 31a of the upper mold 31 and the pedestal 20 is prevented from being lifted. The resin material to be injected fills the mold cavity 36, passes through the air vent gap S, fills the inside of the vent tube 40, and the injection is completed. After the material is cured, air pressure is applied from the release air discharge hole 33 to separate the molded product from the mold. The state after taking out is shown in FIG. At this time, the holder 20 is buried in the thin burr 53 filled in the air vent gap S between the upper die 31 and the holder 20, and the holder is placed with a hammer from the arrow direction e in FIG. By tapping 20, the holder 20 and the thin burr 53 are extracted in the arrow direction f to complete the molding operation.

  However, in the conventional structure for preventing the holder 20 from being lifted by the O-ring 51, the resin material enters and adheres into the concave groove 52 into which the O-ring 51 is fitted. It takes time and effort to work. In addition, since the resin material adheres to the O-ring 51 itself, it is necessary to clean the O-ring 51, which causes a problem that the molding cycle time becomes long. Further, since the width of the air vent gap S (FIG. 6) is determined by the allowance of the O-ring 51, the adjustment range of the air vent gap S is as small as about 0.1 to 0.5 mm, for example, and cannot be further increased. For this reason, there is a problem that the adjustment range of the thickness of the molded product cannot be increased.

  The present invention has been invented in view of the above-described conventional problems, and the object of the present invention is to prevent the lifting of the holder during resin injection molding using a vent tube, and to clean the holder. It is an object of the present invention to provide a resin molding die that can shorten the molding cycle time by omitting the work and can reduce the cost, and can further widen the range of thickness adjustment of the molded product.

  In order to solve the above-described problem, the present invention provides a placement tube 20 between an upper mold 31 and a lower mold 32, and a vent tube 40 for extracting air from the mold cavity 36 inside the upper mold 31. Removably attached. A projecting portion 43 projecting downward from the lower surface 31 a of the upper mold 31 is provided at the lower end portion of the vent tube 40. In the mold clamping state, a part of the upper end surface 20a of the holder 20 is pressed toward the lower mold 32 by the protrusion 43 of the vent tube 40, and the lower surface 31a of the upper mold 31 and the upper end surface 20a of the holder 20 An air vent gap S that allows communication between the inside of the mold cavity 36 and the inside of the vent tube 40 is formed in a portion other than the protruding portion 43 therebetween.

  By adopting such a configuration, it is possible to prevent the holder 20 from being lifted by the protrusion 43 of the vent tube 40, so that it is not necessary to separately use a conventional elastic member such as an O-ring. It is no longer necessary to form a conventional groove for O-ring on the end surface 20a, and the upper end surface 20a of the holder 20 is thereby flattened and adhered to the thin burr 53 (thin burrs filled in the air vent gap S). ) Can be easily removed from the holder 20, so that the holder 20 can be used for the next molding without cleaning. Furthermore, by increasing the protrusion height H of the protrusion 43 of the vent tube 40, for example, when the protrusion 43 is made of resin, it is possible to greatly change the amount of collapse of the protrusion 43 during mold clamping. Thereby, the adjustment amount of the air vent gap S can be made larger than before, and the thickness adjustment range of the molded product can be expanded.

  Further, the lower mold 32 is provided with a release air discharge hole 33 for releasing the holder 20 by air pressure when the mold is opened, and is inserted into the release air discharge hole 33 on the lower end surface 20b of the holder 20. It is preferable to project the positioning convex portion 21 to be positioned, and in this case, the positioning convex portion 21 allows the holder 20 to be accurately and easily set with respect to the lower mold 32, so that the molding cycle time can be reduced. It becomes possible to shorten further.

  According to the present invention, the protruding portion provided at the lower end portion of the vent tube can prevent the holder from being lifted, so that it is not necessary to form a conventional groove for O-ring on the upper end surface of the holder, and the resin material is removed. This can eliminate the cleaning work of the laying element for shortening the molding cycle time and reduce the cost. In addition, by increasing the height of the vent tube protrusion, the adjustment amount of the air vent gap can be increased compared to the conventional one, and the thickness adjustment range of the molded product is expanded. As a result, the product strength is increased by increasing the thickness of the molded product. It is possible to adjust the material reduction by reducing the thickness of the molded product

It is sectional drawing explaining the resin molding metal mold | die provided with the upper mold | type of 1 embodiment of this invention, the lower mold | type, and the holder. (A) is sectional drawing of the vent tube provided with the piece part with a projection part inserted in the upper mold | die same as the above, and (b) is a bottom view. It is explanatory drawing in the case of removing an insert and a thin burr | flash from a molded article after shaping | molding same as the above. (A) is a perspective view of the wash bowl which is a molded product same as the above, (b) is a sectional view taken along line EE of (a). It is sectional drawing explaining the use condition which attached the drain pipe to the drain outlet part of the wash bowl same as the above. It is sectional drawing of the resin molding metal mold | die explaining the basic composition of this invention. FIG. 7 is a plan view of a keeper with the O-ring of FIG. 6 attached thereto. (A) is an exploded sectional view for explaining a molded product, an inserter and a thin burr after being molded using the resin mold of FIG. 6, and (b) is a removal of the inserter and the thin burr from the molded product. It is explanatory drawing in the case of doing.

  Hereinafter, the present invention will be described based on embodiments shown in the accompanying drawings.

  FIG. 4 shows a drain port 2 provided at the bottom of a resin wash bowl 1. The drain port portion 2 includes a fitting recess 4 into which the lower end portion of the inner peripheral surface of the drain port portion 2 that opens in the vertical direction is recessed outwardly so that the drain tube 5 (FIG. 5) is fitted from below. The upper end portion of the inner peripheral surface of the mouth portion 2 has a stepped shape that is a cover portion 3 that covers the upper side of the drainage cylinder 5. For example, an acrylic resin is selected as the material of the wash bowl 1.

  As shown in FIG. 1, a resin molding die 30 for molding the wash bowl 1 with the stepped drainage port 2 is inserted into the upper die 31 that is a movable die and the upper die 31 so as to be freely inserted and removed. The vent tube 40, the lower die 32, which is a fixed type, and the pedestal 20 disposed between the upper and lower dies 31, 32, and other configurations excluding the pedestal 20 and the vent tube 40 are shown in FIG. It is basically the same as the resin molding die shown in.

  A vent pipe 35 whose upper and lower ends are opened is fixed inside the upper mold 31, and a vent tube 40 is inserted into the vent pipe 35 so as to be freely inserted and removed. The center side of the lower surface 31 a of the upper mold 31 is wider than the upper end surface 20 a of the pedestal 20, and a part thereof overlaps with the upper end surface 20 a of the pedestal 20.

  The vent tube 40 of this example is configured by integrally connecting a tube main body 41 and a piece 42 with a projection 43. The hole 42a of the piece part 42 is opened to an air vent gap S formed between the upper mold 31 and the holder 20 during mold clamping, and a plurality of holes protruding from the outer periphery of the lower end of the hole 42a of the piece part 42 are provided. The protrusion 43 protrudes below the lower surface 31a of the upper mold 31 and presses a part of the upper end surface 20a of the lay 20 toward the lower mold 32 during mold clamping. The piece portion 42 with the protrusion 43 is made of, for example, resin, and PE is used in this example. The number of the protrusions 43 is, for example, four as shown in FIG. 2, the external appearance of the protrusions 43 is, for example, a cone or a column, and the height H is, for example, 0.5 to 1.5 mm. For example, d is 0.5 to 2 mm. Of course, not only these numerical values but also the number, material, shape, height, dimensions, and the like of the protrusions 43 can be appropriately changed in design.

  On the other hand, the uppermost central surface 32a of the lower mold 32 has a shape that forms the cover 3 of the drain port 2, and one end of the release air discharge hole 33 is opened at the center. Yes. The other end of the release air discharge hole 33 is connected to an air supply source (not shown).

  The holder 20 is placed on the upper surface 32 a of the lower mold 32. A positioning convex portion 21 projects from the center side of the lower end surface 20b of the holder 20, and this positioning convex portion 21 is inserted into the release air discharge hole 33 of the lower mold 32 so that the holder 20 is The lower mold 32 can be set with high accuracy. The holder 20 has a ring shape that forms the insertion recess 4 of the drain port portion 2, and the thickness of the holder 20 becomes the vertical length of the insertion recess 4 as it is, and the outer diameter of the holder 20. The dimension becomes the inner diameter dimension of the insertion recess 4 as it is. The upper end surface 20a of the holder 20 of this example is formed as a flat surface.

  Next, the molding operation procedure will be described.

  First, as shown in FIG. 1, the positioning element 20 is placed on the upper surface 32 a of the lower mold 32 in a state where the positioning convex portion 21 of the lower end surface 20 b of the positioning element 20 is inserted into the release air discharge hole 33 of the lower mold 32. After setting, the upper die 31 is lowered and clamped. At this time, the resin protrusion 43 provided on the piece 42 of the vent tube 40 presses a part of the upper end surface 20a of the holder 20 with its elastic force to hold down the holder 20, and the upper die 31. An air vent gap S is formed in a portion other than the protrusion 43 between the holder 20 and the holder 20. When the resin material is injected into the mold cavity 36 in this state, the air in the mold cavity 36 is exhausted into the vent tube 40 from the air vent gap S. The resin material filling the inside of the mold cavity 36 further flows into the vent tube 40 through the air vent gap S. At this point, the infusion is stopped. Thereafter, the resin material is cured by raising the temperature of the mold, and after curing, the mold is opened to take out the molded product and the holder 20. At this time, as shown in FIG. 3, while the air is blown from the release air discharge hole 33 of the lower mold 32, the holder 20 is pushed out together with the thin burr 53 in the arrow direction a. By inverting the obtained molded product up and down, as shown in FIG. 5, a wash bowl having a stepped drainage port 2 in which a cover 3 is formed on the upper side and a fitting recess 4 is formed on the lower side. 1 is obtained.

  After the mold is opened, the bent tube 40 filled with a resin material and hardened is extracted from the vent pipe 35 of the upper mold 31 and discarded, and replaced with a new vent tube 40. The replacement of the vent tube 40 is performed for each molding shot. On the other hand, the holder 20 is reused as it is.

  Thus, the bent tube 40 with the protrusion 43 having the above-described configuration can be used to prevent the pedestal 20 from being lifted up. It is no longer necessary to form a groove, and the upper end surface 20a of the holder 20 can be formed flat. Accordingly, the thin burr 53 adhering to the upper end surface 20a of the holder 20 can be easily removed by hand, so that the holder 20 can be used as it is for the next molding without being cleaned. As a result, the cleaning operation of the pedestal 20 can be omitted, and the conventional O-ring mounting operation is not required, the molding cycle time can be shortened, and a simple structure in which the protruding portion 43 is projected from the existing vent tube 40 is sufficient. Since the O-ring is not required, the mold structure is simplified and the cost is reduced.

  In addition, since the holder 20 can be easily positioned with respect to the lower mold 32 using the release air discharge holes 33 of the lower mold 32, the molding cycle time can be further shortened. Moreover, since the holder 20 can be accurately set on the concentricity of the release air discharge hole 33, the insertion recess 4 formed by the holder 20 and the cover 3 formed by the lower mold 32 are the core. The stepped drainage port 2 including the insertion recess 4 and the cover 3 can be formed with high accuracy without causing any deviation, and as a result, the insertion recess 4 of the drainage port 2. The accuracy of concentric circles between the cover 3 and the cover 3 is improved, the occurrence of variation in each molding can be prevented and the number of defects can be reduced, and the quality of the molded product can be further improved.

  Furthermore, since the protrusion height H of the protrusion 43 of the vent tube 40 is sufficiently larger than the allowance for the conventional O-ring, the amount of collapse of the resin protrusion 43 during mold clamping is greatly changed. Thus, the adjustment amount of the air vent gap S can be increased as compared with the conventional O-ring structure. That is, when the molded product is thick, the amount of crushing at the tip of the projection 43 is reduced, and when the molded product is thin, only the amount of crushing at the tip of the projection 43 is increased. The product thickness adjustment range is expanded, and as a result, the product strength can be increased by increasing the thickness of the molded product, or the material reduction can be adjusted by reducing the thickness of the molded product.

  In addition, in the said embodiment, although the case where the tube main body 41 and the piece part 42 with the projection part 43 were couple | bonded and the vent tube 40 was comprised was illustrated, also with the structure which forms the projection part 43 integrally in the lower end part of the tube main body 41. There may be.

DESCRIPTION OF SYMBOLS 1 Washing bowl 2 Drain port part 3 Cover part 4 Insertion recess 5 Drain cylinder 20 Placer 20a Placement upper end surface 20b Placement lower end surface 21 Positioning convex part 30 Resin mold 31 Upper mold 31a Upper mold Lower surface 32 Lower mold 32a Lower mold upper surface 33 Release air discharge hole 36 Mold cavity 40 Vent tube 43 Projection 53 Thin burr S Air vent gap H Projection height of projection

Claims (2)

  A placement element is arranged between the upper mold and the lower mold, and a vent tube for extracting air from the mold cavity is detachably attached to the upper mold, and an upper mold is attached to the lower end of the vent tube. A protrusion projecting downward from the lower surface is projected, and in the mold clamping state, a part of the upper end surface of the holder is pressed toward the lower mold by the protrusion of the vent tube, and the lower surface of the upper mold An air venting gap for communicating the inside of the mold cavity and the inside of the vent tube is formed in a portion other than the protruding portion between the upper end surface of the holder and the holder. The lower mold is provided with a release air discharge hole for releasing the holder by air pressure when the mold is opened, and a convex portion that is inserted into the release air discharge hole and positioned on the lower end surface of the holder. The resin molding die according to claim 1, wherein a protrusion is provided.

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