JP2002225097A - Injection-molded product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an injection-molded product capable of increasing the height of protruding-type carving and capable of easily enhancing the visibility of a decoration due to the protruding-type carving. SOLUTION: The injection-molded product 13 having a decoration such as a character, a pattern or the like applied to the peripheral surface thereof by the protruding-type carving 11 is obtained by injecting a resin in the cavity 17 formed to a mold 16 consisting of a female mold 14 and a male mold 15. The protruding type carving 11 applied to the peripheral surface 18 along the drawing-out direction X of the female mold 14 or the male mold 15 at the time of mold release has a triangular or trapezoidal cross-sectional shape and the surface 19 becoming the undercut part of the protruding type carving 11 having the triangular or trapezoidal cross-sectional shape is inclined at an angle of 50 deg. or less in the drawing-out direction X with respect to the peripheral surface 18. The height of the protruding-type carving 11 from the peripheral surface 18 is 0.1-0.4 mm and the protruding-type carving 11 is connected to a top part through an R-part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an injection-molded article, an injection-molding mold, and a mold processing method, and more particularly to an injection-molded article in which decorations such as characters and patterns are provided on a peripheral surface by convex engraving.
The present invention relates to an injection mold for molding the injection molded article, and a method of processing the injection mold.

[0002]

2. Description of the Related Art In the case of forming a molded product having a deep concave portion such as a measuring spoon or a container for a detergent from a synthetic resin, injection molding is generally employed. You. According to such injection molding,
The resin flows into a cavity formed by a molding die composed of a female die and a male die, and is solidified. Thereafter, the female die and the male die are extracted to obtain a molded product.

[0003] In addition, such injection-molded articles have, for example, a scale or numeral for measurement in the case of a measuring spoon for detergents, in which the decoration such as letters and patterns is convex on the outer and inner surfaces. May be applied by sculpture. This convex sculpture is obtained by forming a concave groove for molding these decorations on the inner peripheral surface of the female die or the outer peripheral surface of the male die which is a cavity surface, and filling and solidifying the concave with the synthetic resin. And
The decorations such as characters and designs are raised so that they can be easily viewed.

[0004] However, the convex sculpture obtained by the groove can only have a height of, for example, about 0.05 mm, and the visibility of the decoration cannot be sufficiently secured. In other words, when trying to increase the depth of the concave groove to increase the height of the convex sculpture and improve the visibility, the surface serving as the undercut portion when the female or male mold is pulled out becomes too high, and it is impossible. There is a problem in that it becomes difficult to remove the mold, and this surface is sagged at the time of mold release, and the shapeability is deteriorated.

[0005] In addition, the concave groove for molding the decoration is formed on the peripheral surface of the mold by electric discharge machining. However, in the electric discharge machining, the decoration with the concave groove having a shape faithful to the underplate is formed on the cavity surface. On the other hand, masters for electric discharge machining had to be manufactured one by one, which required a lot of time and cost, and the degree of freedom of decoration to be formed was poor.

According to the present invention, an injection-molded article capable of increasing the height of a convex sculpture and easily improving the visibility of a decoration by the convex sculpture, and molding the injection-molded article. The purpose is to provide a mold for injection molding.

Further, the present invention provides a method for easily forming a concave groove for forming a decoration by a convex sculpture on an injection-molded article with considerable flexibility without requiring much time and cost. It is an object of the present invention to provide a mold processing method for an injection mold that can be performed.

[0008]

According to the present invention, characters,
An injection-molded product obtained by performing decoration such as a pattern by convex engraving, wherein the convex engraving has a triangular or trapezoidal cross-sectional shape, and has the triangular or trapezoidal cross-sectional shape. The object has been achieved by providing an injection-molded product in which a surface serving as an undercut portion of a convex engraving is inclined at an angle of 50 degrees or less in a direction in which a molding die is drawn with respect to the peripheral surface. Things.

The present invention also relates to a molding die comprising a female die and a male die for forming the above-mentioned injection-molded article, wherein the inner peripheral surface of the female die or the outer peripheral surface of the male die is provided. On the peripheral surface along the pulling direction at the time of releasing one of the surfaces, a decoration such as a character or a pattern engraved by a concave groove having a triangular or trapezoidal cross-sectional shape is provided, and the triangular shape is provided. Alternatively, the above object is achieved by providing an injection molding die in which both side walls of a concave groove having a trapezoidal cross-sectional shape are inclined at an angle of 50 degrees or less with respect to the inner peripheral surface or the outer peripheral surface. Is achieved.

Further, the present invention relates to a method of processing an injection molding die provided with decoration by a concave groove having a triangular or trapezoidal cross-sectional shape, wherein the inner peripheral surface of the female die or the male is provided. After drawing the trajectory of the center line of the decoration by the concave groove composed of characters, designs, etc. on the outer peripheral surface of the mold, slide the tip of the drill cutter having an apex angle of 80 to 120 degrees along the trajectory. The above object has been achieved by providing a mold processing method characterized by engraving the decoration by engraving the inner peripheral surface or the outer peripheral surface so as to trace the locus. is there.

In the above description, the surface serving as an undercut portion refers to a surface that becomes a resistance when a female die or a male die is pulled out. Further, the peripheral surface along the drawing direction of the female mold or the male mold does not necessarily mean only the peripheral surface parallel to the drawing direction, and such a surface is generally a female mold or a male mold. In view of the ease of pulling out, it is provided at an angle of about 0.5 to 10 degrees with respect to the pulling direction, and includes a surface along a direction that is slightly tilted with respect to the pulling direction. It is the purpose.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An injection-molded article 10 according to a preferred embodiment of the present invention shown in FIG. 1 is a transparent measuring spoon formed of a synthetic resin for measuring a powder detergent, and has a deep concave portion at the bottom. On the inner peripheral surface of a certain measuring unit 13, a scale 12 for measurement, numerals, characters and the like are decorated 12 by a convex sculpture 11.
As shown in FIG.

According to the present embodiment, the measuring spoon 10 is obtained by injection molding. According to this injection molding, the measuring section 13 comprises, as shown in FIG. The resin flows into the cavity 17 formed by the molding die 16 composed of the mold 15 and is solidified. Thereafter, the female mold 14 and the male mold 15 are extracted to obtain a molded product of the measuring section 13. Yes (Fig. 3 (a)
To (c)).

According to the present embodiment, at least one of the convex sculptures 11 formed on the inner peripheral surface 18 of the measuring section 13 along the pulling direction X of the male mold 15 at the time of release from the mold. The convex sculpture 11 extending in a direction intersecting with the triangle has a triangular cross-sectional shape, and the surface 1 serving as an undercut portion of the convex sculpture 11 having the triangular cross-sectional shape
9 is 50 degrees or less in the withdrawal direction X with respect to the inner peripheral surface 18 as shown in FIG.
It is inclined at an angle of θ1.

Further, according to the present embodiment, the height of the convex sculpture 11 having the triangular cross section from the inner peripheral surface 18 is 0.1 to 0.4 mm, and the height of the convex sculpture 11 is Since the tip is curved in an arc shape, the surface 19 serving as the undercut portion and the surface 21 on the opposite side are connected to the top portion 20 via the R portion.

FIG. 2 (a) and FIG.
(C) As shown in (a) to (c), the weighing portion 13 has a cavity portion having an inner peripheral surface formed along the outer peripheral surface, and the cavity portion has a female bottom wall 22 and a female side wall 23. And is surrounded by The female side wall 23 is 0.5 ° away from the drawing direction X, which is a direction perpendicular to the parting line 24.
It is inclined at an angle of about 10 to 10 degrees and stands upright along the drawing direction X.

The male mold 15 has a core portion having an outer peripheral surface shaped along the inner peripheral surface of the measuring portion 13, and the core portion is surrounded by a male side bottom wall 25 and a male side side wall 26. I have. The male side wall 26 is used for the parting line 24.
It is inclined at an angle of about 0.5 to 10 degrees with respect to the drawing direction X, which is a direction perpendicular to the drawing direction, and stands up along the drawing direction X. The male mold 15 has a cavity having a width equal to the thickness of the measuring section 13 by being inserted into the cavity of the female mold 14 and overlapping with the female mold 14 with the parting line 24 interposed therebetween. The part 17 is formed. The male side wall 26 constituting the inner cavity surface of the cavity portion 17 is formed by a mold processing method described later.
The decoration such as graduations, numerals, characters, etc. is provided by the concave groove 27 having a triangular cross-sectional shape obtained by molding the convex sculpture 11.
It is engraved at a depth of 1 to 0.4 mm. This groove 27
Are inclined at an angle of 50 degrees or less with respect to the outer peripheral surface of the male mold 15 so that the concave groove 27 is filled with a synthetic resin and solidified to obtain a convex sculpture 1.
Both the surface 19 serving as the undercut portion 1 and the surface 21 on the opposite side (see FIG. 2B) are inclined at an angle of 50 degrees or less in the drawing direction X with respect to the inner peripheral surface 18. .

According to the present embodiment, the decoration by the concave groove 27 having a triangular cross section is easily formed on the male side wall 26 which is the outer peripheral surface along the pulling direction X of the male mold 15. can do. That is, as shown in FIG. 4, for example, a ball end mill is used as the drill cutter 28 having the apex angle (opening angle) θ2 of 80 to 120 degrees at the tip portion, and the drill cutter 28 is positioned at a predetermined position on the male side wall 26 of the male mold 15. ,
After drawing the trajectory of the center line of the decoration by the concave groove 27 composed of scales and numerals, the ball end mill 2 is moved along the trajectory.
8 by sculpting the side wall 26 so as to follow the trajectory while sliding the tip of the groove 2.
The decoration by 7 is easily engraved.

Here, according to this embodiment, by adjusting the engraving depth by the ball end mill 28,
The concave groove 27 and the convex sculpture 11 molded by the concave groove 27
The depth (height) and width of the groove can be easily adjusted, and by appropriately selecting ball end mills 28 having different apex angles, the side wall surfaces of the concave groove 27 and the surface 19 serving as an undercut portion of the convex engraving 11 can be obtained. And the inclination angle of the surface 21 on the opposite side can be easily adjusted. Further, the tip of the ball end mill 28 has a curved surface of, for example, about R 0.3 mm, so that the bottom of the concave groove 27 and the convex engraving 11 are formed.
Can be formed into an arcuate curved surface. Furthermore, the decoration by the concave groove 27 is formed by drawing the locus of the center line and engraving the side wall 26 while sliding the tip end of the ball end mill 28 along this locus. It is possible to engrave decorations of any shape with a considerable degree of freedom without the troublesome work of drawing and manufacturing masters for electric discharge machining one by one, thereby allowing, for example, as shown in FIG. Various decorations by the convex sculpture 11 can be easily provided on the inner peripheral surface of the measuring section 13 at a considerable height of about 0.1 to 0.4 mm.

According to the present embodiment, the measuring portion 13 of the measuring spoon puts the synthetic resin into the cavity portion 17 of the molding die 16 provided by superposing the male die 15 on the female die 14. After inflow and solidification, FIG.
As shown in (a) to (c), it is formed by sequentially extracting the female mold 14 and the male mold 15. That is, first, the female mold 14 is pulled out below in FIG. 3 and the male mold 15 and the solidified measuring portion 13 are removed from the female mold 14 (see (a)), and then the ejector pin 29 is pressed. By inserting the measuring unit 13 into the center of the unit 15 and pushing out the measuring unit 13, the male die 15 is extracted upward in FIG. 3, and the measuring unit 13 is removed from the molding die 16 ((b)).
And (c)).

Here, according to the present embodiment, the measuring section 13
The inner peripheral surface 18 is molded by the concave groove 27 of the male mold 15 so that the decoration by the convex sculpture 11 is 0.1 to 0.4 m.
m, but the surface 19 serving as an undercut portion of the convex sculpture 11 is inclined at an angle of 50 degrees or less in the drawing direction X with respect to the inner peripheral surface 18. When the mold 15 is extracted, the concave groove 27 can be easily overcome while deforming outward due to the elasticity of the solidified synthetic resin. As a result, the convex engraving 11 can be easily formed without sagging. It will be forcibly pulled out while maintaining the height. According to the present embodiment,
Since the tip of the convex sculpture 11 is curved in an arc shape and the surface 19 serving as the undercut portion is connected to the top portion 20 via the R portion, the occurrence of sagging when the male mold 15 is forcibly removed is prevented. It is possible to avoid more effectively.

The surface 19 serving as the undercut portion of the convex engraving 11 is 50 to 50 mm in the withdrawal direction X with respect to the inner peripheral surface 18.
Preferably, it is inclined at an angle θ1 of 30 degrees. By setting the inclination angle θ1 to 50 to 30 degrees, it is possible to prevent the occurrence of sagging and reduce the shaping property, and to improve the visibility by attaching characters to the characters. It is preferable that the protruding height of the convex sculpture 11 from the inner peripheral surface 18 be 0.1 to 0.4 mm. By setting the protruding height to 0.1 to 0.4 mm, it is possible to improve the visibility by making the characters float and to improve the visibility, and to prevent the occurrence of sagging and to reduce the formability. Absent.

According to this embodiment, the male mold 1
Since the surface 19 serving as an undercut portion of the convex sculpture 11 formed by the concave groove 27 of 5 is inclined at an angle of 50 degrees or less in the drawing direction X with respect to the inner peripheral surface 18, sagging occurs. The height of the convex sculpture 11 can be kept high without any problem, and thus the visibility of the decoration 12 by the convex sculpture 11 can be easily improved.

The present invention is not limited to the above embodiment, but can be variously modified. For example, the convex sculpture does not necessarily have to have a triangular cross-sectional shape, and may have a trapezoidal cross-sectional shape with inclined side surfaces. The concave groove for molding a convex sculpture having a trapezoidal cross-sectional shape can be easily formed by repeatedly carving the peripheral surface of the mold while slightly shifting the locus of the center line using a drill cutter, for example. it can. The decoration by the convex sculpture having the trapezoidal cross-sectional shape has an improved visibility due to an increase in the width.

Also, the convex engraving does not necessarily need to be provided so as to protrude inward from the inner peripheral surface of the injection-molded product. A concave groove is formed in the inner peripheral surface of the female mold, and the convex engraving is formed from the outer peripheral surface of the injection-molded product. It may be provided so as to protrude outward. Furthermore, the present invention is not limited to a measuring spoon of a powder detergent, but can be employed to decorate various other molded products obtained by injection molding such as container containers by convex sculpture.

[0026]

According to the injection-molded article and the injection-molding mold of the present invention, the height of the convex sculpture can be increased, and the visibility of the decoration by the convex sculpture can be easily improved. be able to. In addition, according to the method of working a mold for injection molding of the present invention, a concave groove for forming a decoration by convex sculpture on an injection molded product can be provided with a considerable degree of freedom without much time and cost. Thus, it can be easily formed on the cavity surface of the mold.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a measuring spoon as an injection molded product according to an embodiment of the present invention.

FIG. 2A is a cross-sectional view showing a state in which an injection molded product according to an embodiment of the present invention is formed by a molding die including a female die and a male die, and FIG. It is an A section enlarged view of (a) explaining composition of a sculpture.

FIGS. 3A to 3C are cross-sectional views showing a situation in which an injection molded product is taken out of a molding die.

FIG. 4 is a side view showing an example of a drill cutter.

FIG. 5 is a plan view illustrating decoration by convex sculpture.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Injection molded article 11 Convex sculpture 12 Decoration 13 Measuring part (injection molded article) 14 Female mold 15 Male mold 16 Molding mold 17 Cavity part 18 Inner peripheral surface 19 Surface to be an undercut part 20 Top part 21 Undercut Opposite side 22 Female bottom wall 23 Female side wall 24 Parting line 25 Male bottom wall 26 Male side wall 27 Groove 28 Ball end mill (drill cutter) 29 Ejector pin X Pulling direction

 ────────────────────────────────────────────────── ─── Continued on front page (72) Inventor Takeshi Oumi 2-1-3 Bunka, Sumida-ku, Tokyo F-term in Kao Corporation Research Laboratories 4F202 CA11 CB01 CD30 CK11 CK32 CM31

Claims (5)

[Claims] 1. An injection-molded product obtained by applying decorations such as characters and designs on a peripheral surface by convex sculpture, wherein the convex sculpture has a triangular or trapezoidal cross-sectional shape, and An injection-molded product in which a surface serving as an undercut portion of a convex sculpture having a shape or a trapezoidal cross-sectional shape is inclined at an angle of 50 degrees or less with respect to the peripheral surface in a direction in which a molding die is removed. 2. The height of the convex sculpture having the triangular or trapezoidal cross-sectional shape from the peripheral surface is 0.1 to 0.4.
The injection-molded article according to claim 1, wherein the diameter is in mm. 3. The injection molding according to claim 1, wherein the surface serving as the undercut portion of the convex sculpture having the triangular or trapezoidal cross-sectional shape is connected to a top portion via an R portion. Goods. 4. A molding die comprising a female die and a male die for forming the injection molded product according to claim 1, wherein the inner peripheral surface of the female die or On the peripheral surface along the pulling direction at the time of release of one of the outer peripheral surfaces of the male mold, characters, designs, etc., engraved with concave grooves having a triangular or trapezoidal cross-sectional shape are provided. An injection mold having a concave groove having a triangular or trapezoidal cross-sectional shape, wherein both side surfaces of the groove are inclined at an angle of 50 degrees or less with respect to the inner peripheral surface or the outer peripheral surface. 5. A method for processing an injection molding die provided with decoration by a concave groove having a triangular or trapezoidal cross-sectional shape according to claim 4, wherein the inner peripheral surface of the female die or After drawing the trajectory of the center line of the decoration by the concave groove made of characters, designs, etc. on the outer peripheral surface of the male mold, slide the tip of the drill cutter having an apex angle of 80 to 120 degrees along the trajectory. A mold processing method for engraving the decoration by engraving the inner peripheral surface or the outer peripheral surface so as to trace the locus.