KR101481454B1 - Injection mold for inner cover member of electronic device and method for forming inner cover member using the same - Google Patents

Abstract

Disclosed are an injection mold for an inner cover member of a case for forming an inner cover member of a case for an electronic device with a magnet fixated at a specific position, and a method for forming an inner cover member using the same. The disclosed injection mold for an inner cover member is used for manufacturing an inner cover member by injection-molding a reinforcement unit combined to surround a transparent window while the transparent window is mounted in the cavity formed by closing a first core and a second core, wherein the cavity includes a part corresponding to the central part of the transparent window, a part projected outward with a step at a thinner thickness than the central part of the transparent window, and corresponding to the outer periphery of the transparent window, and a part corresponding to the reinforcement part. On the upper side of the second core corresponding to the reinforcement part, multiple magnet support projections are installed in order to fix the position of the magnet within the cavity, and the multiple magnet support projections are mutually separated so that melted resin in the cavity is penetrated between the multiple magnet support projections to cover the magnet fixed by the multiple magnet support projections.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an injection molding die,

The present invention relates to an apparatus and a method for injection molding an in-cover member of a case of an electronic apparatus such as a smart phone, and more particularly to an apparatus and method for injection molding a member in a cover which inserts a magnet by inserting a magnet into a cavity of the mold, The present invention relates to a method for forming a member in a cover.

Injection molding is a method in which a molten resin is injected into a mold and cooled to form a product. Compared with other molding methods such as compression molding and extrusion molding, And the size is limited, and productivity and workability are excellent, and it is widely used for molding of plastic products.

FIG. 1 is a perspective view showing an example of a smartphone case, and FIG. 2 is a cross-sectional view cut along S1-S1 of FIG. 2. Description of the Related Art A smart phone case (1), which is widely used as a portable communication device in recent years, is becoming more and more likely to be damaged due to a large display panel and falling or collision. Referring to FIGS. 1 and 2 together, the smartphone case 1 includes a base 2 having a concave groove formed therein to be fitted with a smartphone (not shown) And a cover 4 attached to the cover 4 so as to open and close in such a manner as to open and close the cover 4.

The cover 4 has a sheath 6 made of thin leather, a nonwoven fabric or a cloth and an in-cover member 10 which is embedded in the inside of the sheath 6 to maintain the rigidity of the cover 4. The cover member 10 includes a transparent window 11 formed to be transparent so that a part of the display panel of the smartphone can be observed even when the cover 4 is closed and a reinforcing portion 20 provided outside the transparent window 11 Respectively. The reinforcement 20 is covered with the reinforcement 20 and the outer surface of the reinforcing portion 20 is covered with the outer surface of the reinforcing portion 20 so that the transparent window 11 is not covered with the outer surface. Is formed to be slightly smaller than the thickness of the transparent window (11).

The portion of the transparent window 11 of the inside of the cover member 10 is normally covered with a hardness of 4H or more to suppress scratching because the cover is not covered. For example, a polymethylmethacrylate (PMMA) ) Resin. However, if the reinforcing portion 20 is formed of PMMA, the PMMA is brittle and prone to break, so that it is formed of, for example, polycarbonate (PC) resin.

In order to form the in-cover member 10, a sheet made of PMMA resin is pressed on both sides of a sheet made of PC resin, and a portion of the reinforcing portion 20 is left with only a PC resin sheet. A numerical control method is used or a double injection method in which a portion of the transparent window 11 is first injected with a PMMA resin and a portion of the reinforcement portion 20 is subsequently injected with a PC resin is used.

However, in the former numerical control machining method, there is a problem that the numerical control machining area is large and productivity is deteriorated due to an increase in machining cost and a processing time delay. In the latter double injection method, There is a problem that the portion of the reinforcing portion 20 is advanced before curing and the hardness and transparency of the portion of the transparent window 11 is lowered. If the additional work is carried out in order to solve the problems of the hardness and the transparency lowering, the productivity is lowered and the cost is increased.

The smartphone case 1 has a function of automatically turning on the display panel of the smartphone when the cover 4 is opened with respect to the base 2 and automatically turning off the display panel when the cover 4 is closed. In order to realize this function, the magnet 25 is provided in the member 10 inside the cover. The magnet 25 is fixed to the magnet seating groove formed in the reinforcing portion 20 through an adhesive layer 27 made of an adhesive or an adhesive tape. Therefore, additional processes and manpower are required to attach the magnets 25, which leads to a problem of low productivity and high cost.

Korean Patent Registration No. 10-0787735

The present invention provides an in-cover member injection-molding die for molding an in-cover member of an electronic device case having a magnet fixed at a specific position, and a method for forming an in-cover member having the same.

The present invention also provides an in-cover member injection mold for manufacturing an in-cover member of an electronic device case having a small step between a transparent window portion to be inserted into a mold and an injection molded portion, and a method for forming an in-cover member using the same .

The present invention also relates to an in-cover member injection mold for preventing an unnecessary through hole from being formed in a completed in-cover member when a transparent window portion is disposed in a mold and injection molding is performed to manufacture an in-cover member of an electronic device case, and a cover Thereby providing a method of forming an inner member.

The present invention relates to a method of manufacturing an inner cover member by injection-molding a reinforcing portion surrounded and coupled to a transparent window in a state where a transparent window is seated in a cavity formed by closing a first core and a second core, And a portion corresponding to the outer peripheral portion of the transparent window and protruding outwardly in a stepped manner to a thickness thinner than the central portion of the transparent window and a portion corresponding to the reinforcing portion and corresponding to the reinforcing portion Wherein a plurality of magnet supporting protrusions are provided on an upper surface of the second core to fix a magnet in position in the cavity, and the plurality of magnet supporting protrusions are spaced apart from each other, And a plurality of magnet holding protrusions formed in the cavity to cover the magnet fixed by the plurality of magnet holding protrusions, Within the injection member provides a molding die.

The plurality of magnet support protrusions may have magnet supporting surfaces formed to be stepped at the same height to support the magnets apart from the upper surface of the second core.

Wherein at least one guide pin hole is formed in the outer periphery of the transparent window and a portion of the cavity corresponding to the central portion of the transparent window is disposed to have the same thickness as the central portion of the transparent window, The molten resin in the cavity covers the outer peripheral portion of the transparent window so that the resin does not cover the central portion of the transparent window and the outer peripheral portion of the transparent window of the cavity and the portion corresponding to the reinforcing portion have a greater thickness than the outer peripheral portion. Wherein one of the first core and the second core has a first position in which the guide pin hole is arranged so as to be able to move up and down and a second position in which the guide pin can be positioned at a second position, The pins may be disposed.

A lower seating groove is formed on an upper surface of the second core to define a lower seating groove on which a central portion of the transparent window is seated and a lower shape defining groove that defines a lower shape of a cover inner member in a portion other than the central portion, Wherein a center pin of the transparent window is seated in the lower seating groove when one guide pin is fitted in the at least one guide pin hole and the transparent window is lowered to the upper side of the second core, The at least one guide pin hole may be filled with the molten resin when the at least one guide pin is brought into close contact with the core and the molten resin is injected into the cavity after the at least one guide pin is lowered to the second position.

When the central portion of the transparent window is seated in the lower seating groove, a space through which the molten resin penetrates may be formed between the bottom surface of the lower shape defining groove and the outer peripheral portion of the transparent window.

The height difference between the lower seating groove and the lower shape defining groove may be 0.1 to 1 mm.

The in-cover member injection mold according to the present invention is characterized in that the at least one guide pin is raised and lowered to a first position and a second position by at least one pneumatic cylinder having the same number as the number of the at least one guide pin cylinder.

The cross section of the cavity may be curved.

A plurality of weight supporting protrusions are provided on an upper surface of the second core corresponding to one side of the inner member of the cover so as to fix a weight formed of a material having a specific gravity higher than that of the molten resin in the cavity , The plurality of weight supporting protrusions may be spaced apart from each other so as to cover the weight fixed by the plurality of weight supporting protrusions so that the molten resin in the cavity penetrates through the plurality of weight supporting protrusions.

According to another aspect of the present invention, there is provided a method of forming an in-cover member using the in-cover injection molding die of the present invention, comprising: a magnet mounting step of fixing the magnet to the plurality of magnet supporting protrusions, A transparent window mounting step in which the first and second cores are placed on the upper side, a mold closing step in which the first and second cores are closely contacted with each other to form a cavity between them, a resin injection step in which the molten resin is injected into the cavity, And a take-out step of separating the first core and the second core and taking out the product from the upper surface of the second core, wherein in the resin-injecting step, And the molten resin penetrates through the plurality of magnet supporting protrusions to cover the magnets.

The present invention also provides a method of forming an in-cover member using the in-cover injection injection molding die of the present invention, comprising: a magnet mounting step of fixing the magnet to the plurality of magnet supporting protrusions to fix the magnet thereon; A center portion made of a resin having a transparency superior to that of the inner layer and composed of first and second outer layers pressed on both surfaces of the inner layer and an outer peripheral portion formed by protruding the inner layer from the first and second outer layers A transparent window preparation step of preparing a transparent window having at least one guide pin hole formed in the outer peripheral part, a step of preparing a transparent window having a part corresponding to a center part of the transparent window of the cavity in a state of being separated from the first core and the second core, And the guide pin is positioned at the first position, A transparent window mounting step of fitting the guide pin into the guide pin hole, a mold closing step of closely contacting the first core and the second core to form a cavity between the two, A pin lowering step, a resin injecting step of injecting a molten resin into the cavity, a curing step of cooling the molten resin to harden it into a product, and a step of separating the first core and the second core, And a take-out step of taking out the product, wherein in the resin injection step, the molten resin penetrates through the plurality of magnet supporting protrusions to cover the magnet, and the at least one guide pin hole is filled with the molten resin A method for forming a member in a cover is provided.

The length of the outer circumferential portion of the transparent window may be 0.5 to 1 mm.

A coloring additive may be added to the molten resin so that the color of the molten resin is the same as that of the sheath covering the reinforcing portion.

According to the present invention, it is possible to mold an in-cover member having a magnet fixed at a specific position by inserting a magnet and inserting the magnet so that the magnet is fixedly supported at a specific position in the mold cavity. Thus, the productivity is improved and the cost is reduced as compared to the case where the magnet is adhered to the injection-molded product through an additional process.

According to the present invention, the transparent window is fastened with the guide pin when the transparent window as the insert is placed on the upper side of the second core, so that the transparent window can be quickly and accurately placed on the upper side. Therefore, the productivity of the inner member of the cover which is injection-molded by insert injection is improved, the work defects can be reduced, and the production cost can be reduced. This effect is more remarkable when the height difference between the lower seating groove and the lower shape defining groove on the second core side surface is minute.

Further, in the injection-molding mold of the present invention, the guide pin is lowered before the molten resin is injected after the first core and the second core are brought into close contact with each other, so that the guide pin hole is filled with the molten resin and hardened. Therefore, it is possible to prevent a crack caused when the guide pin hole is left in the injection-molded member in the cover member, and the durability of the member can be prevented from being weakened.

FIG. 1 is a perspective view showing an example of a smartphone case, and FIG. 2 is a cross-sectional view cut along S1-S1 of FIG.
3 is a cross-sectional view illustrating an injection molded product formed using an in-cover member injection mold according to an embodiment of the present invention.
4 is a cross-sectional view illustrating an in-cover member injection mold according to an embodiment of the present invention.
FIG. 5 is a plan view showing an upper surface of the second core of FIG. 4. FIG.
FIG. 6 is a perspective view showing the magnet supporting protrusions of FIG. 5, and FIG. 7 is a perspective view showing a modification of the magnet supporting protrusions of FIG.
Figs. 8 to 10 are sectional views sequentially showing the in-cover member forming method using the in-cover member injection-molding die of Fig. 4, which are cut along the line S2-S2 of Fig.
11 and 12 are cross-sectional views showing another embodiment of the in-cover member injection molding die according to the present invention, in which only the first core and the second core are extracted.
13 is a cross-sectional view showing another embodiment of the in-cover member injection-molding mold according to the present invention, in which only the first core and the second core are extracted.
14 is a perspective view showing an example of a smartphone case including a cover inner member formed by using the in-cover injection molding die of FIG.

Hereinafter, an in-cover member injection mold according to an embodiment of the present invention and a method of forming an in-cover member using the same will be described in detail with reference to the accompanying drawings. The terminology used herein is a term used to properly express the preferred embodiment of the present invention, which may vary depending on the intention of the user or operator or the custom in the field to which the present invention belongs. Therefore, the definitions of these terms should be based on the contents throughout this specification.

3 is a cross-sectional view illustrating an injection-molded product formed using an in-cover member injection mold according to an embodiment of the present invention. Referring to FIG. 3, The injection molded product 32 formed using the mold 100 (see FIG. 4) has an inner cover member 10 as shown in FIG. 2 and a gate waste 30 therearound. The in-cover member (10) has a transparent window (11) and a reinforcing portion (20) around the transparent window (11). The transparent window 11 has an inner layer 12 and a first outer layer 13 and a second outer layer 14 stacked on both sides of the inner layer 12.

In this case, the inner layer 12, the first outer layer 13, and the second outer layer 14 may all be made of the same resin material having excellent transparency, but the inner layer 12 is made of a material having relatively high hardness, 1 and the second outer layers 13 and 14 are preferably made of a material having relatively high transparency. This is because the resin material having excellent transparency generally does not have a required hardness, for example, 4H hardness, and therefore, the transparent window 11 is broken by the brittleness of the resin material having excellent transparency This is because there is a high possibility of occurrence of deformation or deformation. Therefore, the inner layer 12 is made of a resin material having a relatively high hardness, and the first and second outer layers 13 and 14 made of a resin having excellent transparency are adhered to both surfaces of the inner layer 12 to improve transparency .

In this case, the inner layer 12 may be, for example, a resin product containing polycarbonate (PC), ABS, or glass fiber, and the first and second outer layers 13 and 14 may be formed of, , Polymethylmethacrylate (PMMA), and the like.

In the present embodiment, the inner layer 12 is a sheet made of polycarbonate resin, and the first outer layer 13 and the second outer layer 14 are sheets made of PMMA (polymethylmethacrylate) resin, The transparent window 11 can be formed. The thicknesses T2, T3 and T4 of the inner layer 12, the first outer layer 13 and the second outer layer 14 are respectively 0.5 mm and the thickness T1 of the transparent window 11 is 1.5 mm.

The transparent window 11 is formed on the outer periphery of the central portion formed by laminating the inner layer 12, the first outer layer 13 and the second outer layer 14 so as to be thinner than the thickness T1 of the central portion, And an outer peripheral portion (17) protruding in a horizontal direction so as to be stepped with the side and lower side surfaces. The outer peripheral portion 17 is present at the boundary portion between the transparent window 11 and the reinforcing portion 20 and the inner layer 12 extends beyond the outer peripheral boundary of the first outer layer 13 and the second outer layer 14 will be. The length P1 of the outer peripheral portion 17 protruding from the outer peripheral boundary of the second outer layer 14 is 0.5 to 1 mm. On the other hand, the outer circumferential boundary of the first outer layer 13 extends further to the periphery than the outer circumferential boundary of the second outer layer 14, and the extended length P2 is 0.2 to 0.4 mm. When the cover 6 (see Fig. 2) of the cover 4 (see Fig. 2) is covered with the reinforcing portion 20 by making such a difference, the boundary line of the casing 6 is not visible through the transparent window 11 A clean and luxurious aesthetic is formed.

The outer peripheral portion 17 of the transparent window 11 can be manufactured by NC machining. That is, after the first and second outer layers 13 and 14 and the inner layer 12 having the same cross-sectional area are first fabricated, the first and second outer layers 13 and 14 of the outer peripheral portion 17 are subjected to NC machining, The outer peripheral portion 17 can be formed. As a result, the NC machining area is reduced, the material requirement is reduced, and the purchase cost is reduced.

The reinforcing portion 20 is formed of polycarbonate (PC) resin and has a thickness T5 of 1 mm. Is formed to be thinner than the thickness T1 of the transparent window 11 in consideration of the thickness of the envelope 6 (see FIG. 6), so that the gap between the lower surface of the first outer layer 13 and the lower surface of the reinforcing portion 20 The height difference T6 formed between the upper surface of the second outer layer 14 and the upper surface of the reinforcing portion 20 is 0.25 mm.

A plurality of guide pin holes 15 (see FIG. 8) are formed in the outer peripheral portion 17 of the transparent window 11 so as to pass through the upper and lower portions. The upper end portion of the guide pin 140 (see FIG. 8) is fitted in the guide pin hole 15 in a one-to-one correspondence in the insert injection molding process so that the transparent window 11 is placed in the correct position in the cavity CAV . If P1 is less than 0.5 mm, it is difficult to form the guide pin hole 15 in the outer peripheral portion 17 and the length of the transparent window 11 The bonding force between the reinforcing portions 20 is weakened and the defective ratio can be increased. On the other hand, in the insert injection molding process, the high-temperature molten resin surrounds the outer peripheral portion 17. If P1 is larger than 1 mm, the outer peripheral portion 17 may be deformed or melted.

At one end of the reinforcing portion 20 near the transparent window 11 is provided a sound transmission aperture 22 opened so that sound generated from a speaker (not shown) of a smart phone (not shown) And when the smartphone case cover 4 (see FIG. 1) is closed at the other end portion of the reinforcing portion 20 remote from the transparent window 12, the protrusion button (not shown) A protruding button receiving groove 23 is formed so as to be recessed so as to accommodate the protruding button receiving groove 23 (not shown).

The reinforcing portion 20 is provided with a magnet 25 so that the display panel of the smartphone is automatically turned on and off when the cover 4 (see Fig. 1) is opened and closed with respect to the base 2 do. The magnet 25 is inserted into the in-cover member injection molding die 100 (see Fig. 4), and the molten resin is injected by a so-called insert injection, 20). Reference numeral 26 denotes a magnet support protrusion 145 (see FIG. 9) for fixedly supporting the magnet 25 in a fixed state in the cavity CAV (see FIG. 9) of the mold 100 Is a groove corresponding to the magnet supporting protrusion.

The gate waste 30 is formed of the same material as the reinforcing portion 20 around the reinforcing portion 20. The gate waist 30 is formed by filling and curing the molten resin in the gate 143 (see FIG. 5) formed to uniformly and rapidly inject the molten resin into the cavity CAV (see FIG. 9). The inside of the cover member 10 can be obtained by cutting off the gate waist 30 along a cutting line 31 between the reinforcing portion 20 and the gate waist 30. The lower end of the gate waist 30 may be the interface with the eject pin 114 (see Fig. 4).

5 is a plan view showing an upper side surface of the second core of FIG. 4, and FIG. 6 is a cross-sectional view of the magnet supporting projection of FIG. 5, And FIG. 7 is a perspective view showing a modified example of the magnet supporting protrusion of FIG. 4 and 5, the in-cover member injection mold 100 according to the embodiment of the present invention includes an upper mold 150 that can be lifted and a lower mold 101 below the upper mold 150. As shown in FIG. The upper mold 150 has an upper mold base 170, an upper circular plate 165 supported thereon, and a first upper core 151 fixedly supported on the upper circular plate 165. A sprue bush (not shown) is provided at the center of the upper mold base 170, which is an inlet through which the molten resin is injection-injected from the outside of the injection-molding mold 100 to the inside. The molten resin flowing into the mold 100 through the sprue bushing 43 flows into the first core 151 through a runner (not shown).

The lower mold 101 includes a lower mold base 102 supported on the floor, a lower circular plate 128 supported by the lower mold base 102 with a spacer 110 interposed therebetween, And a second core 130 fixedly supported on the second core 128. When the second core 130 and the first core 151 are in close contact with each other, molten resin is injected between the two cores to form a cavity CAV defining the shape of the injection molded product 32 (see FIG. 3).

The cavity CAV is defined by the upper surface of the second core 130 and the lower surface of the first core 151. A lower seating groove 133 in which a center portion of a transparent window 11 (see FIG. 3) as an insert is seated is formed on the upper surface of the second core 130 and a lower seating groove 133 in which a reinforcing portion 20 3) is formed on the upper surface of the lower-side surface of the lower-side surface. 3) is seated in the lower seating groove 133 and the lower seating recess 133 is recessed more concave than the lower shape defining recess 135. [ A difference in height is formed between the lower seating groove 133 and the lower shape defining groove 135 by a difference in height between the lower surface of the first outer layer 13 and the lower surface of the reinforcing portion 20 T6) (see FIG. 3). In the embodiment shown in FIG. 3, the height difference (T6) is 0.25 mm, but the present invention is not limited thereto and can be smaller or larger. For example, the height difference between the lower seating groove 133 and the lower shape defining groove 135 may be 0.1 to 1 mm.

3 and 9, the cavity CAV includes a portion corresponding to the central portion of the transparent window 11, a portion corresponding to the outer peripheral portion 17 of the transparent window 11, As shown in FIG. A portion of the cavity CAV corresponding to the central portion of the transparent window 11 is disposed to have the same thickness as the center portion of the transparent window 11 so that the molten resin in the cavity CAV The center portion is not covered. A portion of the cavity CAV corresponding to the outer circumferential portion 17 of the transparent window 11 and a portion corresponding to the reinforcing portion 20 have a larger thickness than the outer circumferential portion 17 of the transparent window 11 So that the molten resin in the cavity CAV covers the outer peripheral portion 17.

5 and 6, the upper side of the second core 130, specifically, the lower shape defining groove 135, is provided with upwardly protruding portions 3 (see FIG. 5) for fixing the magnet 25 in the cavity Magnet supporting protrusions 145 are provided. The three magnet support protrusions 145 are provided at positions corresponding to the three vertexes of an equilateral triangle when viewed from above and are spaced apart from each other. The magnet 25 can be aligned so that the center of the equilateral triangle coincides with the center of the disk-shaped magnet 25 and can be lowered to fit the magnet 25 into the space between the three magnet support protrusions 145, (25) is brought into contact with the bottom surface of the lower shape defining groove (135) and fixed in position without moving in the horizontal direction. The molten resin introduced into the lower shape defining groove 135 penetrates through the three magnet supporting protrusions 145 to cover the magnet 25 supported by the magnet supporting protrusions 145. [

The three magnet support protrusions 146 shown in Fig. 7 may be provided in the lower shape defining recess 135 of Fig. 5 in place of the three magnet support protrusions 145 shown in Fig. The three magnet support protrusions 146 shown in Fig. 7 have magnet support surfaces 147 that are stepped at the same height. The three magnet supporting surfaces 147 support the lower outer peripheral surface of the disk-shaped magnet 25 at three points. When the magnet 25 is aligned and lowered so that the center of an equilateral triangle formed by the three magnet supporting protrusions 146 and the center of the disk-shaped magnet 25 coincide with each other, The lower surface of the outer circumferential portion of the magnet 25 is contacted with the magnet supporting surfaces 147 so that the magnet 25 is held in contact with the upper surface 142 of the second core 130, Specifically, the bottom surface of the lower shape defining groove 135. [ However, the three magnet support protrusions 145 and 146 and the disc-shaped magnet 25 shown in Figs. 5 to 7 are merely examples, and for example, four magnet support protrusions and a square magnet are also applicable.

On the other hand, at one side end of the lower shape defining groove 135, a sound transmission hole forming protrusion 137 protruded upward to define a sound transmitting hole 22 (see FIG. 3) 135 are provided with projecting button receiving groove forming protrusions 138 projecting upward to define the projecting button receiving grooves 23 (see FIG. 3).

Referring again to FIGS. 4 and 5, an upper seating groove 153 (see FIG. 9) in which the central portion of the transparent window 11 (see FIG. 3) is seated is provided on the lower side of the first core 151, An upper shape defining groove 155 (see Fig. 9) is formed to define the upper shape of the reinforcing portion 20 (see Fig. 3) around the seating groove 153. [ The upper seating groove 153 and the upper shape defining groove 155 correspond to the lower seating groove 133 and the lower shape defining groove 135, respectively. An upper surface of the second outer layer 14 (see FIG. 3) is seated in the upper seating groove 153, and the upper seating groove 153 is more concave than the upper shape defining groove 155. The height difference between the upper seating groove 153 and the upper shape defining groove 155 is a difference in height between the upper surface of the second outer layer 14 and the upper surface of the reinforcing portion 20 T7) (see FIG. 3).

A gate 143 is formed concavely around the lower shape defining groove 135 and a gate 143 is connected to the lower shape defining groove 135. When the upper mold 150 is in close contact with the lower mold 101, the lower end of the runner (not shown) is connected to the gate 143. Therefore, the molten resin flowing into the mold 100 through the sprue bush (not shown) is injected into the cavity (CAV) through the runner and the gate 143.

The in-cover member injection mold 100 further includes a plurality of eject pins 114 for lifting and separating the injection molded product 32 from the upper surface of the second core 130. The upper end of the eject pin 114 is connected to the gate 143 or the lower shape defining groove 135 and the lower end of the eject pin 114 is connected to the plate 112 between the lower mold base 102 and the lower circular plate 128, As shown in Fig. The molten resin injected into the cavity CAV is cured and the injection molded product 32 (see FIG. 3) is transferred to the upper surface of the second core 130 after the upper mold 150 is raised and separated from the lower mold 101 The platen 112 rises and the plurality of eject pins 114 rise and the injection molded product 32 is lifted and separated from the side surface of the second core 130. [

The in-cover member injection-molding mold 100 further includes four guide pins 140 for guiding the transparent window 11 (see FIG. 8) to be seated in the lower seating groove 133. The guide pin 140 extends upward and downward to the lower mold base 121 through the second core 130 and the lower circular plate 128 and the upper end thereof is connected to the lower shape defining groove 135 Or is lower than or equal in height to the lower shape defining groove 135. The lower shape defining groove 135 is formed at a predetermined position of the lower shape defining groove 135, Specifically, the guide pin 140 has a first position (see FIG. 8) in which the upper end of the guide pin 140 protrudes higher than the bottom surface of the lower shape defining groove 135, and an upper end of the guide pin 140, (See Fig. 10), which is lower than or equal to the height of the bottom surface of the base plate (see Fig. 10).

The plurality of guide pins 140 correspond to a plurality of guide pin holes 15 (see FIG. 8) formed in the transparent window 11 (see FIG. 8). When the upper ends of the plurality of guide pins 140 are fitted to the plurality of guide pin holes 15, the transparent window 11 (FIG. 8) is accurately aligned on the lower seating groove 133, 11 is lowered, the transparent window 11 is correctly seated in the lower seating groove 133. If the guide pin 140 is not provided, the operator can move the transparent window 11 to the lower seating groove 133 due to the small height difference T6 (see FIG. 3) between the lower seating groove 133 and the lower shape defining groove 135, So that a work error frequently occurs, and the productivity of the in-cover member 10 may also be deteriorated.

The lower mold base 102 is provided with a plurality of pneumatic cylinders (not shown) which are in one-to-one correspondence with the guide pins 140 and which elevate the plurality of guide pins 140 between the first position and the second position. cylinders 104 are fixedly supported on the cylinder supports 103. As shown in Fig. The lower end of the guide pin 140 penetrates the plate 112 and is coupled to the pneumatic cylinder 104. The lower mold base 102 is provided with a first mold base 102 for supplying air outside the lower mold base 102 to the inside of the pneumatic cylinder 104 or for discharging air inside the pneumatic cylinder 104 to the outside of the lower mold base 102 And second air inlet / outlet flow paths 107 and 108 are formed.

The first air inlet and outlet flow passage 107 is connected to the upper side of the pneumatic cylinder 104 and the second air inlet and outlet flow passage 108 is connected to the lower side of the pneumatic cylinder 104. Air is supplied into the pneumatic cylinder 104 through the first air inlet and outlet passage 107 and air inside the pneumatic cylinder 104 is discharged to the outside of the lower mold base 102 through the second air inlet and outlet flow path 108 , The guide pin 140 is lowered to the second position (see FIG. 10). On the other hand, air is supplied into the pneumatic cylinder 104 through the second air inlet / outlet flow path 108 and air in the pneumatic cylinder 104 flows through the first air inlet / outlet flow path 107 to the outside of the lower mold base 103 When discharged, the guide pin 140 rises to the first position (see FIG. 8).

The in-cover member injection-molding mold 100 further includes cooling means for cooling the molten resin injected into the cavity (CAV) to be cured. Specifically, the cooling means may include refrigerant flow passages 149 and 159 through which the coolant such as cooling water passes through the second core 130 and the first core 151. The coolant flows through the coolant passages 149 and 159 to cool the second core 130 and the first core 151 to cure the molten resin injected into the cavity CAV.

Figs. 8 to 10 are sectional views sequentially showing the in-cover member forming method using the in-cover member injection-molding die of Fig. 4, which are cut along the line S2-S2 of Fig. Hereinafter, the in-cover member forming method using the in-cover member injection-molding mold 100 shown in FIG. 4 will be described in detail with reference to FIGS. 8 to 10 sequentially. The method of forming an in-cover member according to an embodiment of the present invention includes a magnet mounting step, a transparent window preparing step, a transparent window mounting step, a mold closing step, a guide pin descending step, a resin injection step, a curing step, and a takeout step.

8, the magnet mounting step is a step of mounting the magnets 25 to the plurality of magnet supporting protrusions 145 in a state where the first core 130 and the second core 151 (see FIG. 9) are spaced apart from each other So that the magnet 25 is prevented from moving in the horizontal direction within the lower shape defining groove 135. The manner in which the magnet 25 is sandwiched between the plurality of magnet support protrusions 145 has been described above with reference to FIGS. 5 and 6, and a duplicate description will be omitted. The magnet supporting protrusion 145 may be replaced with the magnet supporting protrusion 146 of Fig. 7 in the magnet mounting step.

The transparent window preparation step is a step of preparing the transparent window 11 described above with reference to FIG. 3, and redundant description of the transparent window 11 is omitted. The transparent window mounting step is to place the transparent window 11 on the upper surface of the second core 130 in a state where the first core 130 and the second core 151 (see FIG. 9) are spaced apart from each other . 9, the center of the transparent window 11 is brought into contact with a portion corresponding to the central portion of the transparent window 11, and at the same time, the plurality of guide pins 140 are placed in contact with the first So as to be fitted in the plurality of guide pin holes 15. [

The upper ends of the plurality of guide pins 140 are inserted into the plurality of guide pin holes 15 formed in the outer peripheral portion 17 of the transparent window 11 and the transparent window 11 is lowered to lower the central portion of the transparent window 11 To the lower seating groove 133. Specifically, when the transparent window 11 is lowered so that the lower surface of the first outer layer 13 of the transparent window 11 comes into contact with the upper surface of the second core 130, And is correctly aligned and seated in the groove 133. The outer peripheral portion 17 of the transparent window 11 invades the region of the lower shape defining groove 135 when the central portion of the transparent window 11 is seated in the lower seating groove 133. [ A gap is formed between the bottom surface of the lower shape defining groove 135 and the outer peripheral portion 17 so that the molten resin can penetrate.

Next, referring to FIG. 9, the mold-closing step is a step of forming a cavity (CAV) between the first and second cores 151 and 151 by closely contacting the first and second cores 151 and. The cavities CAV are formed by closely contacting the first and second cores 151 and 131 by lowering the upper mold 150 (see FIG. 4). When the first core 151 and the second core 131 are in close contact with each other, the second outer layer 14 of the transparent window 11 is fitted and seated in the upper seating groove 153 of the lower side of the first core 151, The shape defining groove 155 and the lower shape defining groove 135 together define the shape of the reinforcing portion 20 (see FIG. 10). At this time, the outer circumferential portion 17 of the transparent window 11 comes into contact with the region of the upper shape defining groove 155, and molten resin can penetrate between the outer circumferential portion 17 and the top surface of the upper shape defining groove 155 A gap is formed. The sound transmission hole forming protrusions 137 and 157 of the second core 130 and the first core 151 are also in close contact with each other.

The upper ends of the plurality of guide pins 140 are pushed down by the upper surface of the first core 151. Since the guide pin 140 is supported by the pneumatic cylinder 104 (see FIG. 4), even when the lower end of the first core 151 collides with the upper end of the guide pin 140, the first core 151 and the guide pin 140 are not damaged or broken.

10, the lowering step of the guide pins 140 moves the upper ends of the plurality of guide pins 140 to the plurality of guide pin holes 15 See Fig. 8). As a result, the plurality of guide pin holes 15 are opened. 10, the height of the upper end of the guide pin 140 at the second position becomes equal to the height of the lower shape defining groove 135. [ As described above, the plurality of guide pins 140 are lowered by the operation of the pneumatic cylinder 104 (see Fig. 4).

Next, the resin injection step is a step of injecting a molten resin such as, for example, molten PC resin into the cavity (CAV) (see FIG. 9) into the cavity (CAV). The molten resin is also filled in the gate 143 (FIG. 5) and filled into the open guide pin hole 15 (see FIG. 8), so that the guide pin hole 15 disappears. Further, the molten resin penetrates between the plurality of magnet supporting protrusions 145 to cover the magnets 25 and sticks to the magnets 25.

Next, the curing step is a step of cooling the molten resin and curing the molded product 32 (see Fig. 3). The refrigerant flows through the refrigerant flow paths 149 and 159 to facilitate the heat exchange, so that the molten resin can be quickly cured. The injection molded product 32 has a transparent window 11 integrally formed with a reinforcing portion 20, a magnet 25 and a gate waist 30 (see FIG. 3). In this case, the molten resin may contain a coloring additive. The color of the additive may be the same color as the color of the envelope 6 (see FIG. 2) or may have a color that can match the color of the envelope 6, so that even if a part of the envelope 6 is removed, (20) is exposed to the outside with the same color as that of the outer skin (6) or a color matching the color of the outer skin (6).

The molten resin may be a material having excellent bending strength. Examples of the above-mentioned molten resin material include PC, PC containing glass paste and PA, and resin containing 15% to 30% of nylon. However, it is clear that the present invention is not limited to these materials.

In the taking-out step, the upper mold 150 (see FIG. 4) is lifted to separate the first core 151 and the second core 130, and the injection-molded product 32) (refer to FIG. 3). The upper end of the eject pin 114 pushes up the gate waist 30 (see FIG. 3) and the reinforcing portion 20 when the upper plate 150 is raised and the plate 112 (see FIG. 4) The molded product 32 is separated from the upper surface of the second core 130.

The operator picks up the injection molded product 32 (see Fig. 3) separated from the side of the second core 130 and takes it out of the mold 100 (see Fig. 4). A magnet supporting protrusion corresponding groove 26 (see FIG. 3) is formed around the magnet 25 in the ejected molded product 32 taken out. The magnet supporting projection corresponding groove 26 is formed in such a resin injection step that the portion is not filled with the molten resin due to the magnet supporting protrusion 145. [

After the injection molded product 32 is taken out, it is cut along the cutting line 31 (see FIG. 3) and the gate waste 30 (see FIG. 3) is removed from the injection molded product 32, do. The operator can proceed with the molding process of the new injection molded product 32 by mounting the new transparent window 11 and the new magnet 25 on the side of the empty second core 130. The injection-molded product 32 manufactured in this manner is filled with the molten resin to harden the guide pin hole 15 (see FIG. 8). Therefore, it is possible to prevent a defect that cracks are formed in the guide pin hole 15, and the durability is improved. The molten resin adheres to the magnet 25 and hardens so that the reinforcing portion 20 (see FIG. 3) and the magnet 25 are integrally formed, no adhesive agent such as an adhesive or an adhesive tape is required, .

On the other hand, the in-cover member 10 (see FIG. 3) manufactured by the mold 100 (see FIG. 4) can be re-pressurized by the mold hydraulic device. As a result, the density of the resin increases and the bending prevention and the impact strength of the in-cover member 10 increase.

11 and 12 are cross-sectional views showing another embodiment of the in-cover member injection-molding mold according to the present invention, in which only the first core and the second core are extracted. 11, the in-cover member injection mold according to another embodiment of the present invention includes a first core 151_2 and a second core 130_2 which are in close contact with each other to form a cavity CAV_2, The elements are the same as those of the in-cover member injection mold 100 of Fig. The lower side of the first core 151_2 forming the cavity CAV_2 protrudes downwardly in a curved shape and the upper side of the second core 130_2 forming the cavity CAV_2 is curved downwardly So that the cross section of the cavity becomes a curved shape. Accordingly, when the central portion of the inner cover material injection-molded by the mold shown in Fig. 11 is cut in the lateral direction, the cross section becomes curved.

12, the in-cover member injection mold according to another embodiment of the present invention includes a first core 151_3 and a second core 130_3 which are in close contact with each other to form a cavity CAV_3, The components are the same as those of the in-cover member injection-molding metal mold 100 of Fig. The lower surface of the first core 151_3 forming the cavity CAV_3 protrudes downwardly in a curved shape and the upper surface of the second core 130_3 forming the cavity CAV_3 is curved downwardly So that the cross section of the cavity becomes a curved shape. Accordingly, when the central portion of the inner cover material injection-molded by the mold shown in Fig. 12 is cut in the longitudinal direction, the cross section becomes curved.

As shown in Figs. 11 and 12, when a mold having a curved section of a cavity is applied, it is possible to injection-mold the member in the cover bent in the longitudinal direction or curved in the lateral direction, Various kinds of cover members can be manufactured according to the degree of warpage.

13 is a cross-sectional view showing still another embodiment of the in-cover member injection molding die according to the present invention, in which only the first core and the second core are extracted and FIG. 14 is a cross- FIG. 1 is a perspective view illustrating an example of a smartphone case including a cover inner member formed using a cover. FIG. 13, the in-cover member injection mold according to another embodiment of the present invention includes a first core 151_4 and a second core 130_4 which are in close contact with each other to form a cavity CAV_4, The components are the same as those of the in-cover member injection-molding metal mold 100 of Fig. The transparent window 11 and the magnets 25 (see FIG. 8B) are formed before the molten resin is injected into the cavity CAV_4 by forming the cavity CAV_4 in close contact with the first core 151_4 and the second core 130_4, A weight 28 is seated on the upper surface of the second core 130_4. Specifically, the transparent window 11 is seated in the lower seating groove 133_4 of the second core 130_4, the magnet 25 is seated in the lower shape defining recess 135_4 of the second core 130_4, (28) is seated on one side of the lower shape defining groove (135_4). This position is a position corresponding to one side of the in-cover member 10_4 (see Fig. 14) injected through the mold shown in Fig.

Although not shown in FIG. 13, the lower shape defining groove 135_4 of the second core 130_4 is provided with a plurality of weight supporting projections projected to fix the weight 28 in the cavity CAV_4. The plurality of weight supporting protrusions are spaced apart from each other similarly to the plurality of magnet supporting protrusions 145 and 146 described with reference to Figs. 5 to 7, and the weight supporting protrusions 145 and 146 are formed so that the weight 28 is fitted into the space formed inside the plurality of weight supporting protrusions. . However, the number and arrangement of the plurality of weight supporting protrusions may vary depending on the shape and size of the weight 28.

When the molten resin is injected into the cavity CAV_4 formed by closely contacting the first core 151_4 and the second core 130_4, the molten resin penetrates through the plurality of weight supporting protrusions and is moved by the plurality of weight supporting protrusions Thereby covering the fixed weight 28. 14, a weight 28 is integrally formed with the transparent window 11 and the magnet 25 on the in-cover member 10_4 formed by curing the molten resin. 1 and 2, the smartphone case 1_4 includes a base 2 on which a smart phone (not shown) is seated and fixed, and a cover 4_4 that can be opened and closed with respect to the base 2 And the cover 4_4 has an inner cover member 10_4 and a sheath 6 wrapped around the inner cover member 10_4.

The weight 28 is a phenomenon in which the cover 4_4 is unintentionally opened due to the elasticity of a connection portion (not shown) where the cover 4_4 and the base 2 are connected to each other when the cover 4_4 is closed with respect to the base 2 And is provided on one side of the in-cover member 10_4 which is closer to the base 2 when the cover 4_4 is closed and is away from the base 2 when the cover 4-4 is opened. The weight 28 is intended to cancel the elasticity of the connecting portion by making the weight heavier, so that the weight 28 is formed of a material constituting the reinforcing portion 20_4, that is, a material heavier than the specific gravity of the molten resin. For example, steel, stainless steel, or the like can be applied. 13 and 14, the weight 28 is composed of one long and thin plate, but a plurality of pieces may be spaced apart. Further, the shape of the weight is not limited to a long and thin plate.

On the other hand, the weight 28 is formed of a permanent magnet or a ferromagnetic metal as a material. When the cover 4_4 is closed, a permanent magnet or a ferromagnetic metal A corresponding material (not shown) may be provided. This makes it possible to more effectively suppress the phenomenon that the magnetic attraction force acts between the weight 28 and the corresponding part of the base 2 to unintentionally open the cover 4_4 to the base 2 have.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the scope of the present invention. Therefore, the true scope of protection of the present invention should be defined only by the appended claims.

10: Inside cover member 25: Magnet
100: In-cover member injection injection molding die 101: Lower mold
102: lower mold base 145, 146: magnet supporting projection
128: lower original plate 130: second core
140: guide pin 150: upper mold
151: first core 165: upper disk

Claims (13)

delete delete Forming a reinforcing portion surrounding and enclosing the transparent window in a state in which a transparent window is seated in a cavity formed by closing the first and second cores,
The cavity includes a portion corresponding to the central portion of the transparent window and a portion corresponding to the outer peripheral portion of the transparent window projected outwardly in a stepped manner with a thickness thinner than the center portion of the transparent window and a portion corresponding to the reinforcing portion ,
A plurality of magnet supporting protrusions protruded to fix a magnet in the cavity are provided on an upper surface of the second core corresponding to the reinforcing portion,
Wherein the plurality of magnet supporting protrusions are spaced apart from each other so as to cover a magnet fixed by the plurality of magnet supporting protrusions by penetration of the molten resin in the cavity through the plurality of magnet supporting protrusions,
At least one guide pin hole is formed in the outer periphery of the transparent window,
A portion of the cavity corresponding to the central portion of the transparent window is disposed so as to have the same thickness as the central portion of the transparent window so that the molten resin in the cavity does not cover the central portion of the transparent window,
Wherein the molten resin in the cavity covers the outer periphery of the transparent window so that the outer periphery of the transparent window and the portion corresponding to the reinforcement have a greater thickness than the outer periphery,
Wherein one of the first core and the second core is provided with a guide pin capable of being raised and lowered to a first position where the guide pin hole is inserted and a second position where the guide pin is lowered to form the cavity face, Wherein the mold is formed by injection molding. The method of claim 3,
A lower seating groove is formed on an upper surface of the second core to define a lower seating groove in which a central portion of the transparent window is seated,
The central portion of the transparent window is seated in the lower seating groove when the at least one guide pin located at the first position is fitted in the at least one guide pin hole and the transparent window is lowered to the upper side of the second core,
The first core is brought into close contact with the second core and the at least one guide pin is lowered to the second position and the molten resin is injected into the cavity so that the at least one guide pin hole is filled with the molten resin Wherein the cover member is made of a resin. 5. The method of claim 4,
Wherein when the central portion of the transparent window is seated in the lower seating groove, a gap penetrating the molten resin is formed between the bottom surface of the lower shape defining groove and the outer peripheral portion of the transparent window. 5. The method of claim 4,
Wherein the height difference between the lower seating groove and the lower shape defining groove is 0.1 to 1 mm. 5. The method of claim 4,
Further comprising at least one air pressure cylinder for raising and lowering the at least one guide pin to a first position and a second position, the number being equal to the number of the at least one guide pin. Injection Molding Mold. The method of claim 3,
Wherein an end face of the cavity is curved. Forming a reinforcing portion surrounding and enclosing the transparent window in a state in which a transparent window is seated in a cavity formed by closing the first and second cores,
The cavity includes a portion corresponding to the central portion of the transparent window and a portion corresponding to the outer peripheral portion of the transparent window projected outwardly in a stepped manner with a thickness thinner than the center portion of the transparent window and a portion corresponding to the reinforcing portion ,
A plurality of magnet supporting protrusions protruded to fix a magnet in the cavity are provided on an upper surface of the second core corresponding to the reinforcing portion,
Wherein the plurality of magnet supporting protrusions are spaced apart from each other so as to cover a magnet fixed by the plurality of magnet supporting protrusions by penetration of the molten resin in the cavity through the plurality of magnet supporting protrusions,
A plurality of weight supporting protrusions are provided on an upper surface of the second core corresponding to one side of the inner member of the cover so as to fix a weight formed of a material having a specific gravity higher than that of the molten resin in the cavity ,
Wherein the plurality of weight supporting protrusions are spaced apart from each other so as to cover the weight fixed by the plurality of weight supporting protrusions by penetration of the molten resin in the cavity through the plurality of weight supporting protrusions. Molding mold. delete A method of forming an in-cover member using the in-cover member injection-molding die according to claim 3,
A magnet mounting step of positioning and fixing the magnet to the plurality of magnet supporting protrusions;
An inner layer which is a sheet made of a resin and a central portion made of a resin having a transparency superior to that of the inner layer and composed of first and second outer layers pressed on both surfaces of the inner layer, A transparent window preparing step of preparing a transparent window including an outer peripheral part formed outwardly protruding from the outer peripheral part and having at least one guide pin hole formed therein;
Placing a center portion of the transparent window in contact with a portion of the cavity corresponding to a central portion of the transparent window in a state where the first core and the second core are spaced apart from each other, A transparent window mounting step to be fitted in the guide pin hole;
Closing the first core and the second core to form a cavity between the first core and the second core;
A guide pin lowering step of lowering the guide pin to the second position;
A resin injection step of injecting a molten resin into the cavity;
A curing step of cooling the molten resin to cure the product; And
And a take-out step of separating the first core and the second core and taking out the product from the upper surface of the second core,
Wherein in the resin injection step, the molten resin penetrates through the plurality of magnet supporting protrusions to cover the magnets, and the at least one guide pin hole is filled with the molten resin. 12. The method of claim 11,
Wherein a length of an outer peripheral portion of the transparent window is 0.5 to 1 mm. 12. The method of claim 11,
Wherein the molten resin is added with a coloring additive that has the same color as that of the sheath covering the reinforcing portion.

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