KR20070003088A - Injection mold for producing small parts - Google Patents

Abstract

A metal mold for an injection molding to produce a small part is provided to save a metal mold cost for producing an other part by exchanging only a part of a lower core. In a metal mold for an injection molding to produce a small part, an upper core(110) and a lower core(120) faces each other capable of being separated from each other. In the lower core, a base lower core(124), an external form determining core(122), and an internal form determining core(123) is laminated in order of above statement from the bottom of the lower core. A vertically movable fixing lower core supports the external form determining core downward from outside. A cavity is formed between an inner surface of a through hole in the internal form determining core and an outer surface of protrusive bar which is standing on the external form determining core.

Description

Injection Mold for Small Parts Production {INJECTION MOLD FOR PRODUCING SMALL PARTS}

1 is a cross-sectional view showing a conventional injection molding mold,

Figure 2 is a cross-sectional view showing a mold for injection molding for producing small parts according to the present invention.

<Description of the symbols for the main parts of the drawings>

1: molded article 10: mold

15: cavity 20: upper core

22: gate 25: cavity

30: core 100: mold

110: upper core 112: gate

120: core 122 122: core for appearance determination

123: core for determining the shape 124: base core

125: up and down flow fixing core 126: up and down flow fixing bolt

The present invention relates to an injection molding mold for producing small parts, and more particularly, to efficiently exchange only a part of a lower core without having to prepare and replace an entire mold when producing a multi-component exchange of small parts such as gears, pulleys, and bushes. The present invention relates to an injection molding mold for producing small parts that can be produced as a product.

In general, injection molding injects molten resin into a mold to solidify, thereby repeatedly producing a product having a predetermined shape.

1 is a cross-sectional view showing a conventional injection molding mold.

The injection mold 10 is composed of a pair of upper core 20 and lower core 30 which are separated and interviewed up and down so as to be separated from each other, and between the upper core 20 and the lower core 30, a molded article ( A cavity 25 is formed in a shape corresponding to the shape of 1), and the gate 22 is vertically formed in the upper core 20 to inject molten resin into the cavity 25. ) Is formed.

In the manufacture of the molded article using the mold 10, when molten resin is injected into the cavity 25 inside the mold 10 through the gate 22, the injected molten resin solidifies in the cavity 25 to form a molded article ( 1), the upper core 20 and the lower core 30 are separated from each other to form the molded article 1 formed from the cavity 25.

On the other hand, in recent years, in order to meet various demands of consumers, the diversity of design and quality of electric and electronic parts and various household goods has become important, and as a result, the number of molds required by injection companies is increasing due to the large number of small quantity production parts. Increased and frequent mold replacement is required, the productivity is reduced, as well as the situation is enormous cost.

In this regard, in the case of parts produced in small quantities of many kinds, the shapes between parts are often similar, but even in this case, a mold cost is required because a pair of molds 10 must be prepared for each part, and molds are required even during injection. Since the separation, reinstallation of the cooling oil, and preheating of the mold have to be repeated, productivity is greatly reduced.

That is, similar parts may include a gear, a pulley, a bush, and the like, and if any number of teeth of the gear or pulley is different, a separate mold 10 has to be prepared.

The present invention was devised to solve the above problems, and in the case of a mold for producing small parts such as gears, pulleys, and bushes, the main functional surface of the corresponding parts to prevent the top core side of the parts from being pinched. It is an object of the present invention to provide an injection molding die that can be produced efficiently by exchanging only a part of the main core, leaving all the other mold parts intact.

Injection molding mold for producing small parts of the present invention for achieving the above object is composed of an upper core and a lower core to be interviewed separately up and down to be divided into each other, the lower core, the lower core from the lower base A core, an inner crystal lower core, and an outer crystal lower core are stacked in this order, and the upper and lower flow fixing lower cores are formed to press and support the outer lower crystal core from the top to the lower direction. A cavity corresponding to the shape of the molded article is formed in a space formed between the inner surface of the through hole formed in the lower core and the outer surface of the protruding rod formed to be inserted into the lower core for determining the external shape. It is characterized in that only the lower core for the external appearance and the lower core for determining the appearance.

The above objects and various advantages of the present invention will become more apparent from the preferred embodiments of the invention described below with reference to the accompanying drawings by those skilled in the art.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Conventionally, in the case of molds for producing small parts such as gears, pulleys and bushes, all of the main functional surfaces of the parts were provided on the lower core side in order to prevent the upper core side from sticking.

Therefore, in the present invention, in view of this point for the efficient production of small quantities of the multi-parts of the corresponding parts without replacing the entire mold 100, only a part of the lower core 120 that forms the main functional surface of the corresponding parts ( 100).

Figure 2 is a cross-sectional view showing a mold for injection molding for producing small parts according to the present invention.

The mold 100 is composed of a pair of upper cores 110 and lower cores 120 that are separated and interviewed to be divided up and down so that the upper and lower cores 110 are vertically formed therein. Will be.

The lower core 120 is formed of a lower determination core 122, an inner determination lower core 123, a base lower core 124, and an upper and lower flow fixing lower core 125, each of which will be described below.

The shape determination lower core 122 has a through hole formed at its center in the vertical direction, and a shape corresponding to the outer shape of the molded product 1 is processed on the inner surface of the through hole.

The inner core for determining the internal shape 123 is provided to be in close contact with the lower side of the lower core 122 for determining the external shape, the center is formed so that the protrusion bar is inserted, the outer side of the molded bar (1) As the shape corresponding to the inner shape is processed, the protruding rod is inserted into the center of the through hole of the lower core 122 for determining the external shape so that the molded article 1 is formed in the space between the inner side of the through hole and the outer side of the protruding rod. The cavity corresponding to the shape of is formed.

The base lower core 124 is provided to be in close contact with the lower side of the lower core for determining the internal shape described above.

The upper and lower flow fixing lower cores 125 are the uppermost outermost crystal lower cores in the state in which the above-described base lower core 124, the internal crystal lower core 123, and the external lower crystal core 122 are stacked. 122 by pressing from the outside to the lower direction to be fixed, the up and down flow fixing bolt 126 is fastened in a supporting state, thereby fixing the entire lower core 120 so as not to flow up and down.

In the mold 100 as described above, the master mold portion that is commonly used without being replaced when the mold is exchanged for the production of other molded products 1, the upper core 110, the base lower core 124, the vertical flow A fixing lower core 125 and a vertical flow fixing bolt 126 are included, and the exchange mold part to be exchanged for the production of each molded product 1 includes the outer core 122 for external appearance determination and the lower core for internal resistance determination. 123 will be included.

Thus, only one master mold portion may be prepared, and only the external shape determination lower core 122 and the internal shape determination lower core 123 may be prepared and replaced for each molded product 1.

Referring to the mold exchange process, when the other component (1) is to be produced, first loosen the up and down flow fixing bolts 126, expose the up and down flow fixing lower core 125, and in turn, determine the appearance core ( 122) and the lower core 123 for the internal determination.

Subsequently, all of the internal crystal lower core 123 and the external crystal lower core 122 corresponding to the parts 1 to be produced are replaced or only one of the cores for the external crystals, and then the upper and lower flow fixing lower cores ( 125) after mounting the up and down flow fixing bolt 126, the mold replacement process is completed.

As a result, since only a part of the lower core 120 needs to be replaced without replacing the entire mold 100, the replacement is easy and can be made in a short time, thereby improving productivity, and for the production of each part 1. Since only a part of the core 120 needs to be prepared, the mold cost can be greatly reduced.

In the foregoing description, it should be understood that those skilled in the art can make modifications and changes to the present invention without changing the gist of the present invention as merely illustrative of a preferred embodiment of the present invention.

According to the present invention, since only a part of the cores need to be replaced without having to prepare and replace the entire mold for producing one kind of parts, the mold cost can be greatly reduced, and the replacement can be easily performed, thereby improving productivity. Can be achieved.

Claims (2)

It consists of upper and lower cores that are separated and interviewed up and down to be divided into each other. The core is, The lower core is stacked in order from the bottom to the base lower core, the inner crystal lower core, the outer crystal lower core, and the upper and lower flow fixing lower core which presses and supports the outer lower crystal for uppermost part from the outer side to the lower direction. The cavity corresponding to the shape of the molded article is formed in the space formed between the inner surface of the through hole formed in the inner core for determining the inner shape and the outer surface of the protruding rod formed in the lower core for determining the outer shape. Injection molding mold for the production of small parts, characterized in that to replace only the inner core for determining the shape and the lower core for determining the external shape during the production of the molded article. The method of claim 1, The molded article, Injection mold for producing small parts, characterized in that any one of the gear, pulley, bush.

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