JPH0718826U - Injection mold - Google Patents

Abstract

(57) [Abstract] [Purpose] In an injection-molding die for molding an injection-molded article having undercut-shaped projections, the release of the undercut-shaped projections from the slide core without impairing the function of the undercut-shaped projections. The purpose is to improve sex. By processing both the slide core 40 side and the movable side mold plate 30 side as a cavity for forming an undercut-shaped projection 51 formed integrally with an injection molded body 50, the slide core 40 is opened when the mold is opened. The releasability between the undercut protrusion 51 and the undercut protrusion 51 is improved.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an injection molding die for molding a resin molded body in which an undercut-shaped projection is formed using a slide core, and in particular, it facilitates release from the resin molded body and the slide core, The present invention relates to an injection molding die that prevents deformation of an undercut protrusion.

[0002]

[Prior art]

 For example, as a mold structure for injection molding a resin molded body having undercut-shaped protrusions, as shown in FIG. 7, a fixed-side mold plate 1 and a movable-side mold plate 2 which are engageable with each other, It is composed of a slide core 3 that slides in conjunction with the movable movement of the side template 2, and a resin is formed along a cavity shape defined between the fixed side template 1 and the movable side template 2. The undercut-shaped projections 5 formed integrally with the resin molding 4 while molding the molding 4 are molded by the cavity shape formed in the slide core 3.

Then, when the movable side mold plate 2 moves and the mold is opened, the slide core 3 also slides in the direction of the arrow in FIG. 7, and at that time, as shown in FIG. The undercut-shaped projection 5 tends to be deformed in the sliding direction together with the slide core 3 as a result of the sliding operation. As a countermeasure against this, the undercut-shaped projection 5 should be set to a large thickness or width. The method of strengthening the strength of 5 itself, and as shown in FIG. 9, the outer shape of the undercut projection 5 is set to a taper shape so that the sliding behavior of the slide core 3 can be smoothly performed. Attempts have been made.

[0004]

[Problems to be solved by the device]

 However, when the thickness or width of the undercut-shaped protrusion 5 is set to be large, the undercut-shaped protrusion 5 is often used as a hook or a locking piece, and the desired flexibility is reduced. However, there were drawbacks that it could not be expected to be fitted smoothly, the mounting workability was reduced, there were many design restrictions, and various problems such as weight increase were brought about.

Further, when the taper is set as shown in FIG. 9, even in this case, reliable mating with the companion component cannot be expected, and there is a problem that the mounting stability is impaired. The present invention has been made in view of such circumstances, and in an injection molding die in which an undercut-shaped projection integrally formed with an injection-molded body is molded using a slide core, the undercut-shaped projection is used. It is an object of the present invention to provide an injection molding die capable of enhancing the mold release property between the slide core and the undercut-shaped protrusion without deteriorating the function of.

[0006]

[Means for Solving the Problems]

 In order to achieve the above object, the present invention comprises a fixed-side mold plate that can be engaged with each other, a movable-side mold plate, and a slide core that slides in association with the operation of the movable-side mold plate. In an injection mold for injecting a molten resin into a cavity defined by each mold plate and a slide core to form an injection-molded article having undercut-shaped projections, the undercut-shaped projections are The cavity to be formed is characterized in that it is formed in both the movable side mold plate and the slide core.

[0007]

[Action]

 As is clear from the above configuration, the undercut-shaped protrusion integrally molded with the injection molded body is molded by injecting resin into the cavity formed in both the movable mold plate and the slide core. When the slide core slides, the undercut protrusions are not deformed by being pulled by the slide core.

Furthermore, since it is not necessary to set a conventional taper on the undercut-shaped protrusion, it is possible to prevent occurrence of problems (ease of disengagement, displacement of the fitting position, etc.) with respect to fitting with a mating component.

Further, since it is not necessary to increase the width and thickness of the undercut-shaped projection, the flexibility is excellent, and the degree of freedom in modeling is increased, which contributes to weight reduction.

[0010]

【Example】

 Hereinafter, an embodiment of an injection molding die according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a cross-sectional view of an essential part of a first embodiment of an injection molding die according to the present invention, FIG. 2 is a cross-sectional view of an undercut-shaped projection formed by the injection molding die, and FIGS. FIG. 6 is an explanatory view showing a modification of the injection molding die according to the present invention.

1 and 2, a first embodiment of an injection molding die according to the present invention will be described.

First, the injection molding die 10 according to the present invention slides in a direction orthogonal to the mold opening direction of the fixed-side mold plate 20, the movable-side mold plate 30, and the movable-side mold plate 30 which can be engaged with each other. The slide core 40 is configured to move up and down.

More specifically, the fixed-side mold plate 20 is provided with a gate (not shown), and the injection molding machine is provided in a cavity defined between the fixed-side mold plate 20 and the movable-side mold plate 30. A molten resin supplied from (not shown) is injected and filled through a gate to mold an injection molded body 50 in a desired shape.

In the present invention, the injection molded body 50 integrally provided with the undercut-shaped projection 51 is a molding target, and the undercut-shaped projection 51 is provided between the movable side mold plate 30 and the slide core 40. The molten resin is injected and filled into the cavity formed in the above, and is integrally formed with the injection molded body 50.

By the way, the feature of the present invention is that the undercut-shaped projection 51 is not pulled by the slide core 40 during the sliding operation of the slide core 40, and the good releasability is imparted to the undercut. The point is that the function of the protrusion 51 is not impaired.

That is, the feature is that the cavity forming the undercut-shaped protrusion 51 is formed not only on the slide core 40 side but also on the movable side template 30 side. The parting surface P is set on a line that divides the undercut-shaped protrusion 51 into two in the vertical direction.

Therefore, after the molding is completed, when the movable side mold plate 30 operates, the slide core 40 also slides in the direction of the arrow in FIG. 1, but the cavity of the undercut-shaped protrusion 51 is also formed on the movable side mold plate 30 side. Since it is formed, the undercut-shaped projection 51 is not pulled by the slide core 40, and the deformation of the undercut-shaped projection 51 can be prevented in advance.

As described above, the injection-molding die 10 according to the present invention is fitted to an undercut-shaped projection 51 (a locking piece, a locking hook, or the like, which is integrally molded with the injection-molded body 50. By forming the cavities of the undercut-shaped protrusions 51 not only on the slide core 40 side but also on the movable side mold plate 30 side when molding a protrusion having a function), the undercut when the mold is opened. It is possible to enhance the releasability between the protrusions 51 and the slide core 40. Therefore, it is not necessary to set the width and thickness dimensions of the undercut protrusions 51 to be large, and the undercut protrusions 51 can be separated from the mating parts. It has the advantages that flexibility that affects the mating function can be sufficiently secured, weight reduction can be promoted, and a good mounting function can be obtained.

Further, according to the present invention, since the mold releasability between the slide core 40 and the undercut-shaped protrusion 51 can be enhanced, as shown in FIG. Since the taper angle of the provided taper 52 can be set to the minimum, it is possible to prevent problems related to fitting with the mating parts (e.g., ease of disengagement and misalignment at the time of mating) and to expect reliable mounting to the mating parts. .

Next, FIGS. 3 to 6 show modified examples of the injection molding die 10 according to the present invention, in which the shapes of the undercut-shaped protrusions 51 formed integrally with the resin molded body 50 are respectively shown. Since it has been changed, only a main part will be illustrated and briefly described.

First, in the structure shown in FIG. 3, both sides of the cavity of the movable side mold plate 30 of the undercut-shaped projection 51 are provided in an inclined shape, and the reverse-direction taper 53 is formed in the undercut-shaped projection 51. When the mold is opened, the reverse taper 53 firmly holds the undercut-shaped protrusion 51 on the movable-side mold plate 30, thereby further promoting the releasability between the undercut-shaped protrusion 51 and the slide core 40. is there.

Next, FIGS. 4 and 5 show an embodiment in which a convex portion 54 having the same function as the reverse taper 53 is set in the movable side mold plate 30 of the undercut-shaped protrusion 51.

Also in this embodiment, since the undercut-shaped projection 51 is firmly held by the movable side mold plate 30 when the mold is opened, the releasability between the undercut-shaped projection 51 and the slide core 40 is promoted. The width and thickness of the undercut-shaped protrusion 51 can be set thin.

Further, what is shown in FIG. 6 is not the hook shape so far, but an undercut projection 51 ′ in which a plate 55 and a convex portion 56 integrally formed on the side surface of the plate 55 are formed. The convex portion 56 serves as an undercut portion.

Even in such a shape, if the cavity of the plate 55 is provided on the movable side mold plate 30 side and the cavity forming the convex portion 56 is provided on the slide core 40 side, the plate 55 and the convex portion 56 are formed. Even in the undercut-shaped projection 51 'composed of, there is no deformation at the time of mold opening, and the bending characteristics and the degree of freedom in design can be freely selected. As described above, in the injection-molding die 10 according to the present invention, the injection-molding body 50 in which the undercut-shaped protrusions 51 such as hooks and locking pieces are integrally molded is formed. At this time, since the slide core 40 and the undercut-shaped protrusion 51 can be smoothly released from the mold, various advantages such as prevention of deformation of the undercut-shaped protrusion 51, promotion of weight reduction, and provision of good bending characteristics can be obtained. In addition to the provision, since there is no problem such as deformation even if the slide speed of the slide core 40 is increased, the mold opening speed can be increased and the molding cycle can be shortened.

[0027]

[Effect of device]

 As described above, the injection molding die according to the present invention has the special working effects described below.

(1) Since a cavity for forming an undercut-shaped projection integrally formed with an injection-molded body is provided in both the slide core and the movable-side mold plate, when the mold is opened as in the conventional case, It is possible to effectively solve the problem that the slide core is deformed due to the undercut projection being pulled, and it is possible to prevent the deformation of the undercut projection in advance.

(2) According to the present invention, since the releasability of the undercut-shaped projection and the slide core can be improved, the width and thickness of the undercut-shaped projection can be set small and the locking can be achieved. When it is applied to a hook or a locking piece, it has the effects of increasing flexibility, allowing smooth mounting workability, and promoting product compactness and weight reduction.

(3) According to the present invention, since the releasability between the undercut-shaped protrusion and the slide core can be promoted, the taper conventionally set for the undercut-shaped protrusion can be minimized. When applied to locking pieces and locking hooks, there is no problem with the mating with mating parts (such as ease of disengagement or displacement of the mating position), which improves the mounting stability. Have.

(4) According to the present invention, the mold-releasing speed between the undercut-shaped protrusion and the slide core is enhanced, and thus the sliding speed of the conventional slide core is limited, so that the mold opening speed is also limited. However, the sliding speed of the slide core can be increased, and the molding cycle of the injection molding die can be accelerated.

[Brief description of drawings]

FIG. 1 is a sectional view showing a first embodiment of an injection molding die according to the present invention.

FIG. 2 is a sectional view taken along line II-II in FIG.

FIG. 3 is a view corresponding to FIG. 2 showing a second embodiment of the present invention.

FIG. 4 is a cross-sectional view of a main part showing a third embodiment of the present invention.

5 is a sectional view taken along line VV in FIG.

FIG. 6 is a cross-sectional view of an essential part showing a fourth embodiment of the present invention.

FIG. 7 is a cross-sectional view showing a conventional injection-molding die for molding an injection-molded body having undercut-shaped protrusions.

FIG. 8 is an explanatory diagram showing a behavior of a conventional undercut-shaped protrusion when the mold is opened.

FIG. 9 is an explanatory view showing the shape of a conventional undercut-shaped protrusion.

[Explanation of symbols]

 10 Injection Mold 20 Fixed Side Mold Plate 30 Movable Side Mold Plate 40 Slide Core 50 Injection Molded Body 51 Undercut Protrusion 52 Taper 53 Reverse Taper 54 Convex Part 55 Plate 56 Convex Part P Parting Line

Claims (1)

[Scope of utility model registration request] 1. A fixed-side template (20) which can be engaged with each other.
And a movable side template (30) and a slide core (40) that slides in association with the operation of the movable side template (30). Each template (20, 30) and slide core (40) An injection molding mold for injecting a molten resin into a cavity defined by and forming an injection-molded body (50) having an undercut-shaped projection (51), wherein the undercut-shaped projection (51) The mold for injection molding is characterized in that the cavity for forming is formed in both the movable side mold plate (30) and the slide core (40).