JP3413520B2 - Composite injection molding method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention sequentially injects a plurality of types of synthetic resins to form a base of a molded article, a frame one step lower than the base and the inside of the frame, or a base of the body and a push-cut hole. Related to the compound injection molding method of integrally molding different color resins, it is possible to perform compound injection sequentially while changing the cavity shape with the mold closed state without changing the fixed side or movable side mold. The present invention relates to a molding method.

[0002]

2. Description of the Related Art When a plurality of synthetic resins are integrally injection-molded, (a) a fixed side and a movable side, which form a cavity which is a base of a main body of a first resin, are placed in a frame for injecting a second resin. Either the fixed side or the movable side that forms the cavity, (b) or the fixed side and the movable side that forms the base of the main body of the first resin, the frame that is lower than the second resin, or the protrusion. Either the fixed side or movable side that forms the cavities that become marks / characters, either the fixed side or the movable side that forms the cavities in the frame of the third resin,
(C) Furthermore, the fixed side and the movable side, which form the cavities that form the base of the main body having the push-out hole for the first resin, and the fixed side and the movable side, which form the cavities in the push-out hole for injecting the second resin. Either side is prepared, and when the first resin and the second resin or the third resin are injected, the respective dies are exchanged to cope with the problem. Although neither the fixed side mold nor the movable side mold is replaced, only the base of the main body is injection-molded, and then (1) a sticker with a mark / character printed on the base of the main body, (2) There are things such as hot stamping marks and letters on the base.

[0003]

As described above, in the case of preparing a plurality of dies on either the fixed side or the movable side as in the prior art, the manufacturing cost of the dies increases and the dies Replacing is also complicated. Further, it takes a long time to replace the mold, which makes it difficult to set molding conditions. And, in order to speed up the exchange of molds, it is necessary to prepare an injection molding machine in which the mold mounting plate is rotatable so that a plurality of molds can be mounted, and as a result, the equipment price rises. There is a point. 2) When sticking a seal, there is a problem that it is necessary to prepare a separate seal and a jig for improving work efficiency and sticking accuracy. 3) In the case of hot stamping, there is a problem that equipment is required and both costs are inevitably increased. The present invention has been made in view of the above problems, and an object of the present invention is to provide a composite injection molding method capable of efficiently performing injection molding with one injection mold at low cost.

[0004]

As a method for solving the above-mentioned problems of the prior art, the compound injection molding method according to the invention of claim 1 is for injection molding comprising a fixed side 10 and a movable side 20. A composite injection molding method of integrally molding a base 1a of a molded article main body and a resin of a different color with a part of the base 1a by a mold, wherein the fixed side 10 has the above-mentioned base through a first gate 11. 1a, a first sprue 12 for the first resin that communicates with the frame 1b one step lower than the base, and a second resin second spout that communicates with the inside 1e of the one-step lower frame 1b via the second gate 21. A first slide piece (2) that is provided with a sprue (13) and forms a frame (1b) that is one step lower than the base of the base (1a), and is capable of advancing and retracting in the mold opening direction and in a direction orthogonal to the mold opening direction, and the base. The frame 1b, which is one step lower than 1a, is closed to form a cavity in the frame 1e, which allows the mold to move forward and backward The ability of the second slide piece
A second gate 21 communicating with the second sprue 13 is provided on the movable side 20. The second gate 21 penetrates the opening 1d of the frame 1b one step lower than the base and communicates with the inside 1e of the frame. It is arranged in a submarine-like arrangement and is formed on a gate piece 23 which can be projected by an ejector plate 24.When the first slide piece 2 moves forward, the second gate 21 is closed, and when the second slide piece 3 moves forward, It is configured to communicate with the two gates 21, the first resin is injected from the first sprue 12, the base of the main body and the frame 1b one step lower than the base are primary-injected, and the second resin is injected from the second sprue 13 to the above. 1e in the frame that is one step lower than the base
It is characterized in that a series of operations up to the secondary injection for filling is performed with the mold closed state.

In the composite injection molding method according to the second aspect of the present invention, the base 1h of the molded article main body and a part of the base 1h of different colors are formed by the injection molding die including the fixed side 10 and the movable side 20. A composite injection molding method for integrally molding a resin,
The fixed side 10 has a push gate 1j through a first gate 11.
Sprue for the first resin communicating with the base 1h having
12 and a second sprue 13 for the second resin, which communicates with the press-cutting hole 1j via the second gate 21, and forms the press-cutting hole 1j, which is orthogonal to the mold opening direction and the mold opening direction. The first slide piece 2A that can be moved back and forth and the push-cut hole 1j are closed to form a cavity of the frame 1i that is one step lower than the base in the push-cut hole 1j, and can be moved back and forth only in the mold opening direction. The second slide piece 3A is provided, and the movable side 20 has a second gate 21 that penetrates the push-cut hole 1j and communicates with the inside of the cavity, and has a submarine shape that communicates with the second sprue 13. The ejector plate 24
Is formed in a gate piece 23 which can be protruded by means of the first sprue 2A, and the second gate 21 is closed when the first slide piece 2A moves forward, and communicates with the second gate 21 when the second slide piece 3A moves forward. The first resin is injected from 12 and the base of the main body having the press-cut hole 1j is primary-injected, and the second sprue
It is characterized in that a series of operations from 13 to the secondary injection for injecting the second resin and filling the frame 1i one step lower than the base in the press-cut hole 1j is performed in the mold closed state.

In the composite injection molding method according to the third aspect of the present invention, a resin of different color is applied to the base of the molded article body and a part of the base by means of an injection molding die consisting of the fixed side 10 and the movable side 20. A composite injection molding method of integrally molding, wherein the fixed side 10 is provided with a first sprue 12 for a first resin, which communicates with a base 1t of a main body through a first gate 11, and a second gate 91. The second sprue 13 for the second resin, which communicates with the frame 1m one step lower than the base, and the third sprue 14 for the third resin, which communicates with the inside 1q of the frame one step lower through the third gate 93, are provided. , 1m lower frame than the base of the main body is cut off,
A first slide piece 70 that can move forward and backward in the mold opening direction and a direction orthogonal to the mold opening direction, and a frame 1m lower than the above base by one step.
And a second slide piece 78 capable of advancing and retreating in a mold opening direction and a direction orthogonal to the mold opening direction which is symmetrical to the first slide piece 70, and a frame 1m lower than the base of the main body is closed. Then, a cavity is formed in the frame 1q, and a third slide piece 86 that can advance and retreat only in the mold opening direction is arranged. The movable side 20 communicates with the frame 1m which is one step lower than the base. The second gate 91 is formed in a submarine-like arrangement that communicates with the second sprue 13, is formed on a gate piece 90 that can be projected by an ejector plate, and the third gate 93 that communicates with the frame 1q is In a submarine-like arrangement that communicates with the three sprue 14, it is formed on a gate piece 92 that can be projected by an ejector plate, and seals the second gate 91 and the third gate 93 when the first slide piece 70 advances. Second Sla The third gate 93 is sealed while the third bridge 93 is communicated with the second gate 91 when the moving piece 78 moves forward, and the third gate 93 is connected when the third sliding piece 86 moves forward, and the first resin is injected from the first sprue 12. The base of the body
Primary injection of 1t, second resin is injected from the second sprue 13 to secondary injection of the lower frame 1m, third resin is injected from the third sprue 14 to fill 1q inside the lower frame. It is characterized in that a series of operations up to the third injection is performed in the mold closed state.

The composite injection molding method according to claim 4 is the composite injection molding method according to claim 1, 2 or 3,
It is characterized in that marks / characters are formed on the surface of the first or second slide piece 2, 78 constituting the frames 1b, 1m which are lower than the base of the main body.

The composite injection molding method according to claim 5 is the composite injection molding method according to claim 1, 2 or 3, wherein
The secondary or tertiary injection is characterized by using a transparent resin or a resin of a different color from the base of the main body.

The compound injection molding method according to claim 6 is the compound injection molding method according to claim 4 or 5, in which the second or third slide piece 3 for closing the frames 1b, 1m lower than the base of the main body. , 86, the same marks / characters 2c, 2n as the first or second slide piece 2, 78 are formed, and the raised marks / characters formed by the primary or secondary injection are fitted or the marks / characters are pressed. It is characterized in that the secondary or tertiary injection is performed in this state.

The composite injection molding method according to claim 7 is the composite injection molding method according to claim 1 or 3 or 4 or 5 or 6, wherein the secondary or tertiary injection is incompatible with the base of the main body. It is characterized in that it is made of resin and is communicated with and integrated with the negative angle space a formed in the frames 1b and 1m lower than the base.

The composite injection molding method according to claim 8 is the composite injection molding method according to claim 4 or 5, wherein the surface height of the raised marks / characters 1c, 1n is the base 1 of the main body.
It is characterized in that it is formed slightly lower than a and 1t and that the surface of the marks / characters 1c and 1n is covered with a secondary or tertiary injection transparent resin. The compound injection molding method according to claim 9 is the compound injection molding method according to claim 4 or 5, wherein the surface heights of the raised marks / characters 1c, 1n are substantially the same as the bases 1a, 1t of the main body. It is characterized in that they are formed identically and secondary or tertiary injection is performed with the surfaces of the embossed marks / characters 1c, 1n pressed by the second or third slide pieces 3, 86.

A composite injection molding method according to claim 10 is the composite injection molding method according to claim 1 or 2 or 3 or 4, wherein the second or third slide piece 3, 86 is moved forward. Inject the first resin from one sprue 12 and base 1 of the main body
Frames 1b, 1i, 1m lower than a, 1h, 1t and inside frame 1
It is characterized in that e and 1q are molded by primary injection.

According to the eleventh aspect of the composite injection molding method, the base 1a of the molded article body and a resin of a different color different from each other are formed on the base 1a of the molded article main body by the injection molding die including the fixed side 10 and the movable side 20. A first injection sprue 12 for the first resin communicating with the base 1a via the first gate 11 and the frame 1b one step lower than the base on the fixed side 10. And inside the frame of the lower frame 1b through the second gate 91
A second slide 13 for the second resin communicating with 1e is provided, and a frame 1b that is one step lower than the base 1a is formed, and a first slide capable of advancing and retracting in the mold opening direction and a direction orthogonal to the mold opening direction. A second slide piece that closes the piece 70 and the frame 1b that is one step lower than the base 1a to form a cavity in the frame 1e, and that can move back and forth in the mold opening direction and the direction orthogonal to the mold opening direction.
The second gate 91, which is disposed so as to face 78, penetrates the opening 1d of the frame 1b one step lower than the base and communicates with the inside 1e of the frame one step lower than the base. , In a submarine-like arrangement that communicates with the second sprue 13, is formed on a gate piece 90 that can be projected by an ejector plate 24, and when the first slide piece 70 is advanced, it seals the second gate 91, When the second slide piece 78 moves forward, it is configured to communicate with the second gate 91, the first resin is injected from the first sprue 12, the base of the main body and the frame 1b one step lower than the base are primarily injected, and the second sprue 13 is ejected. It is characterized in that a series of operations up to the secondary injection for injecting the second resin and filling the inside of the frame 1e of the frame one step lower than the base is performed in the mold closed state.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a molded product 1 of the first embodiment, and FIGS. 2 to 19 are principle diagrams and embodiment diagrams of the injection molding. In Fig. 1, (1) is a plan view of molded product 1, (2) is molded product 1
The right half center horizontal enlarged view of (3) is a right half center vertical enlarged sectional view of the molded product 1. FIG. 2 is a principle diagram of the steps of the injection molding method, in which (1) is a state diagram at the time of primary injection by the first resin after the first slide piece 2 is lowered and held, and (2) is the first slide. State diagram when the piece 2 is raised, (3) is a state diagram when the first slide piece 2 is retracted, (4) is a state where the second slide piece 3 is lowered and held, and then a second resin piece is used. It is a state diagram at the time of the next injection. FIG. 3 is a sectional view taken along the line AA of FIG. 7 when the first slide piece 2 is lowered to perform the primary injection, FIG. 4 is a sectional view taken along the line AA of FIG. 7 when the first slide piece 2 is raised, and FIG. 7 is a sectional view taken along the line D-D of FIG. 7 when the first slide piece 2 is retracted, FIG. 6 is a sectional view taken along the line A-A of FIG. 7 at the time of secondary injection after the second slide piece 3 is lowered and held, and FIG. 3 is a view in the direction of arrow Y in FIG. 3, FIG. 8 is a view in the direction of arrow Z in FIG. 3, FIG. 9 is a sectional view taken along line BB in FIG. 7, FIG. 10 is a sectional view taken along line CC in FIG. 8, and FIG. EE cross-sectional view of FIG. 3 showing the engagement state of the slide piece 3, FIG. 12 is a FF cross-sectional view of FIG. 3, FIG. 13 is a plan view of the injection molding die, FIG.
4 is a sectional view of an essential part of the injection molding die, FIG. 15 is an operation state diagram of the first slide piece 2 with respect to the operation of the slider 5, and FIG. 16 (1)
16 is a detailed view of the gate portion, (2) is an enlarged sectional view taken along line GG of (1) in FIG. 16, and (3) is an enlarged sectional view taken along line HH of (1) in FIG. Figure
17 is an enlarged cross-sectional view of an essential part around the gate piece 23 of FIG. 14, FIG. 18 is an explanatory view of a negative angle structure on the movable side 20, and FIG. 19 is an enlarged view of an essential part of FIG.

The composite injection molding method according to claim 1 of the present invention is preferably carried out by using an injection molding die having a fixed side 10 and a movable side 20. The fixed side (10) forms a cavity with the movable side (20) to be the molded product (1). In the cavity, a base 1a of a main body, which will be described later, a frame 1b lower than the base, and an embossed mark / character 1c with a projected mark / character are formed in the frame 1e. Figure 16, (1)
(2) As shown in (3), the fixed side 10 is provided with the base 1a of the main body, the frame 1b one step lower than the base, and the embossed mark / character 1c in the same frame 1e via the first gate 11. A first sprue 12 for injecting a communicating first resin, and a second sprue for injecting a second resin communicating between the raised mark / character 1c in the frame 1e through the second gate 21. And 13 are provided.
Further, on the fixed side 10, as shown in FIGS. 3 to 10, the first slide piece 2, the sliders 5 and 6, the slide piece 4, and the second slide piece 3 are provided.
Are arranged respectively. The first slide piece 2 has a frame 1b which is one step lower than the base of the main body, a raised mark, a mark 1c, and a character 2c to be a character 1c in the frame 1e. 2a, and a dovetail groove guide 2b provided in the mold opening direction so as to project to the right side thereof, and are arranged so as to be able to move back and forth in the mold opening direction and in a direction orthogonal to the mold opening direction. The slider 5 is engaged with the dovetail groove 2a and has a dovetail groove guide 5a provided with an upward L-shaped projection at its tip and is configured to move in a direction orthogonal to the mold opening direction. The slide piece 4 is provided between the first slide piece 2 and the slider 5 and has a dovetail groove 4a that engages with the dovetail groove guide 2b. When the slider 5 retracts, the tip of the dovetail groove guide 5a interferes. It is arranged in a portal shape (Figs. 6 and 10). The second slide piece 3 has the above-mentioned frame within the same range as the first slide piece 2.
While blocking 1b to form a cavity in the frame 1e,
Again, the upper end is in the upward-leftward shape in the drawing, and the cam 31 is provided in a U-shape in an arrangement orthogonal to the upward-leftward surface so as to be movable only in the shape opening direction. The slider 6 includes a rail 61 that engages with the cam 31 of the second slide piece 3, and is configured to move in a direction orthogonal to the mold opening direction. On the other hand, on the movable side 20, a second gate 21 protruding from the opening 1d in the frame 1b one step lower than the base 1a of the main body and communicating between the embossed mark and the character 1c is provided. And a divided side surface 22 with the movable side 20 of the gate piece 23 that can be projected by the ejector plate 24 in a configuration that forms a submarine shape that communicates with the.
Is formed in the lower part of the first slide piece 2 (forward)
This forms a frame 1b one step lower than the base 1a of the main body and an embossed mark / character 1c in the frame, and the gate piece 23
The second gate 21 is sealed by abutting the opening 1d of the second slide piece 3, and the second slide piece 3 is lowered (advanced) to close the frame 1b which is lower than the base 1a of the main body to form a cavity in the frame 1e. In addition, it is configured to communicate with the second gate 21. The gate piece 23 is arranged to be out of timing with a predetermined time delay from the operation of the ejector plate 24. That is, the ejector plate 24 on which the brim 30 of the gate piece 23 hangs is released by the dimension L, and the molded product and the second gate 21 are automatically separated at the time of mold release. 14 shows the whole, and FIG. 17 is an enlarged view of a main part of FIG. That is, the gate piece 23 is attached to the tip of the rod 25, and ejector pin 29 that is projected as the ejector plate 24 rises.
And are configured to operate with a delay of the L dimension (see FIG. 17). This is because the collar 30 is the ejector plate 24
Base built in movable plate 32 until immersed in
The groove formed by the ball plunger 27 of 28 in the lower part of the rod 25
26 is engaged to regulate the operation, and the ejector plate 24
When the size rises and comes into contact with the flange 30, the gate piece 23 is projected as the rod 25 is operated. At this time, the second gate 21 is cut from the molded product 1 that has been ejected by the ejector pin 29, and the secondary processing is omitted. When the slider 5 is moved forward, the tip of the injection molding die sinks under the stopper 8, and the first slide piece 2 is held by the stopper 8 from the resin pressure (FIG. 3). Next, when the slider 5 is retracted, the first slide piece 2 is raised (FIG. 4) by the engagement of the dovetail groove 2a and the dovetail groove guide 5a (FIGS. 8 to 10). First slide piece 2
Reaches the space of the fixed side 10, L of the dovetail guide 5a
The first slide piece 2 stops rising at the same time when the tip of the character shape interferes with the slide piece 4, and as the slider 5 retreats, it moves laterally together with the slide piece 4 out of the range of the base 1a of the main body (FIG. 5). . After that, as the slider 6 advances, the rail
The second slide piece 3 descends from the engagement between 61 and the cam 31.
Further, as the slider 6 advances, its lower end surface presses the upper end portion of the second slide piece 3, and the second slide piece 3 is pressed by the resin pressure.
Hold (Fig. 6). Both sliders 5 and 6 are operated by a cylinder S (not shown). Therefore, in the primary injection with the PP resin which is the first resin, the base 1a of the main body formed by the first slide piece 2 by the forward movement of the slider 5
Then, it is injected into the frame 1b, which is one step lower than the base 1a, and the cavity of the raised mark / character 1c in the frame 1e (FIG. 3). After the primary injection, the slider 5 is retracted to laterally remove the first slide piece 2 from the base 1a of the main body (Fig. 5), and then the slider 6 is moved forward to lower the second slide piece 3 (Fig. 6). Secondary injection for filling between the embossed mark and the character 1c in the frame 1e by a different kind of the second resin such as ABS resin or acrylic resin is performed by the second slide piece 3 held by the slider 6. It is injected into the cavity in the frame 1e that encloses the frame 1b. When the secondary injection is completed, the mold is opened and the molded product is taken out.
Before or after the mold is closed, the mold returns to the posture corresponding to the primary injection of the first resin. FIG. 15 shows the operation of the first slide piece 2 associated with the operation of the slider 5. A positioning pin 2d is provided on the lower surface of the center of the first slide piece 2 on the slide piece 4 side.
When the projecting portion forming the one-step lower frame 1b of the base 1a is laterally displaced from the range of the base 1a of the main body, a height high enough not to move the joint surface of the movable side 20 by contact and to interfere with the fixed side 10. When it is located within the range of the base 1a, it fits into the fitting hole 20a provided in the joint surface of the movable side 20 and maintains that position. That is, the first slide piece
The upward movement, the lateral movement, and the downward movement of 2 can be reliably and smoothly performed by the forward and backward operations orthogonal to the mold opening direction of the slider 5. Explaining with reference to FIG. 15, when the slider 5 retracts, the first slide piece 2 moves up, and the positioning pin 2d also moves up, and the dovetail guide 5a of the slider 5 moves.
Moves the slide piece 4 to move the positioning pin 2d together with the first slide piece 2d, 3d, and 5d, and at the same time, causes the protruding portion of the 1st slide piece 2 to follow and move, 2d and 3d, and vice versa. Move the first slide piece 2 by advancing 5
Ha, b, and descent.

Next, a composite injection molding method according to the invention described in claim 4, which is carried out by the injection molding die having the above-mentioned structure, is represented by (1), (2), (3), (in FIG. 2). Description will be made based on the embodiment shown in 4). However, the molded product 1 shown in Fig. 1
Is not for specifying the product, but is shown for the sake of easy understanding of the shape description. 1) First, the first slide piece 2 on the movable side 10 is moved to the position of the base 1a of the main body by the forward movement of the slider 5 and is lowered to mark and mark on the frame 1b one step lower than the base 1a and the frame 1e. 2
c is arranged to form a cavity, and the first slide piece 2 seals the second gate 23, the base 1a of the main body, the lower frame 1b, and the embossed mark / character 1c made of the first resin. Injection is performed (Fig. 2 (1)). 2) After the primary injection, the slider 5 is retracted to raise the first slide piece 2 (Fig. 2 (2)). 3) Further, the first slide piece 2 is laterally removed from the position of the base 1a of the main body by retracting the slider 5 (Fig. 2 (3)). 4) The second slide piece 3 is lowered by the forward movement of the slider 6 to close the one-step lower frame 1b formed of the first resin to form a cavity between the embossed mark and the character 1c in the frame 1e. Secondary injection is performed between the output mark and the character 1c with a second resin of a different color from the first resin (Fig. 2
(Four)). In the above-described embodiment, it is possible to reverse the order of operation of the first slide piece 2 and the second slide piece 3 for implementation. In other words, a frame 1b that is one step lower than the base of the main body on the second slide piece 3, and a mark / character 2c is placed in the frame 1e to perform primary injection as a cavity, and a frame that is one step lower than the base on the first slide piece 2. 1b is closed, a cavity is formed in the frame 1e, and the secondary injection is different,
Other configurations are the same as the above. Next, a composite injection molding method according to the invention described in claim 1 will be described. Although not shown, in the above drawings, the first slide piece of the first embodiment
Only the frame without marks and characters is formed in 2 and within that frame 1
The second resin is secondarily injected into e, and the composite injection molding method according to the invention described in claim 2 is the same as the above-mentioned drawing, but the first slide piece 2 of the second embodiment is used to To cut off a portion, and form a cut-out hole 1j in the base,
Only the second injection of the second resin into the push-cut hole 1j is different, and the other configurations are the same. Furthermore, it goes without saying that the arrangement configuration of the first slide piece 2 and the second slide piece 3 can be reversed and the operation order can be reversed in the same manner as described above. A series of operations of each slide piece forming the cavity shape in the above composite injection is performed not only in the mold open state but also in the mold closed state. It is preferable to release the mold clamping force from the effective use of energy, but in consideration of the time cost of zeroing the residual stress of 15 to 40%, it will not hinder the operation even if residual stress remains. Has been adjusted to.

FIG. 20 is a detailed view of the molded product and the gate portion according to the second embodiment of the above-mentioned claim 2, which is the base 1h of the molded product main body.
Into the frame 1i which is one step lower, there is fitted a stainless steel molding (not shown) having no marks or characters, or pressing the marks or characters. Frame 1 lower than the base 1h
i and the first slide piece 2 that forms the outside thereof in a frame shape presses off a part of the base 1h of the main body, and the base of the main body is primarily injected with the first resin. The press-cut hole 1j is closed to form a cavity, and the press-cut hole 1j is secondarily injected with a second resin. Compared to the first embodiment, a stainless steel molding is used to increase the sense of quality. be able to. This molding method is selected according to the grade of the product. For the first embodiment, a part of the base of the main body is pressed by the first slide piece, and the press cut hole 1j is formed in the base. The only difference is that the second resin is secondarily injected into the cut hole 1j, and the other configurations are the same, so the same reference numerals are given and the description thereof is omitted. Figure 21 shows G2-G2 of Figure 20.
FIG. 22 is an enlarged cross-sectional view of FIG. 20 taken along line H2-H2.
FIG. 23 is a second embodiment, and is a cross-sectional view taken along the line AA of FIG. 7 when the first slide piece 2A is lowered to perform the primary injection, and FIG. 24 is the first slide piece 2A of the same embodiment retracted. 7 is a sectional view taken along the line AA of FIG. 7, and FIG. 25 is a sectional view taken along the line AA of FIG. 7 when the second slide piece 3A of the embodiment is lowered to perform the secondary injection.

In contrast to the above-mentioned two types of resin being subjected to primary and secondary injections, the composite injection molding method described in claim 3 is to subject three types of resin to primary, secondary and tertiary injections. Figure 26
Is a process principle diagram of the injection molding method according to the third embodiment, in which (1) is a state diagram of the primary injection by the first resin after the first slide piece 70 is advanced and lowered and held; )
Is a state diagram of the secondary injection by the second resin after the first slide piece 70 is retracted and the second slide piece 78 is advanced and lowered to be held, (3) is the second slide piece 78 is retracted, FIG. 19 is a state diagram of the third injection by the third resin after the third slide piece 86 is lowered and held. 27 to 33 show an embodiment, in which a first slide piece 70, a slider 76 and a slide piece 74, a second slide piece 78, a slider 84 and a slide piece 8 are shown.
2. A third slide piece 86 and a slider 6 are arranged respectively. The first slide piece 70 is configured to push down the frame 1m, which is one step lower than the base 1t of the main body, and the cam 72 of the first slider piece 70 is moved by the movement in the direction orthogonal to the mold opening direction of the slider 76.
And the rail 77 of the slider 76, the first slide piece
The dovetail guide 71 of 70 is configured to be able to move forward and backward in the dovetail 75 of the slide piece 74 in the mold opening direction, and the second slide piece 78 forms a frame 1m one step lower than the base 1t of the main body, and the slider 84 of the slider 84. By moving in a direction orthogonal to the mold opening direction, the second slide piece
The engagement of the cam 80 of 78 with the rail 85 of the slider 84 allows the dovetail groove guide 79 of the second slide piece 78 to move forward and backward in the dovetail groove 83 of the slide piece 82 in the mold opening direction.
Reference numeral 6 indicates a frame 1m which is one step lower than the base and closes the frame 1m.
By forming a cavity in q and moving the slider 6 in a direction orthogonal to the mold opening direction, the engagement between the cam 87 and the rail 61 allows the slider 6 to advance and retreat only in the mold opening direction. The operation of the first slide piece to the third slide piece is the same as above. Figure 27 shows a partial bottom view of the injection molding die,
The secondary and tertiary injection sprues 12, 13 and 14 are arranged on the horizontal center line of the mold, and engage with the sliders 76 and 84 sandwiching the horizontal center line in a position that does not interfere with the sprue and also interferes with each gate. First and second slide piece 7 with cams 72 and 80 of non-form
0 and 78 are arranged facing each other. FIG. 28 shows a cross-section of the main part of the above-mentioned mold, in which the first slide piece 70 is advanced to push down the frame 1m, which is one step lower than the base 1t, and the base 1t is primarily injected with the first resin. Is. FIG. 29 also shows a state in which the first slide piece 70 is retracted and the second slide piece 78 is moved forward so that the frame 1m one step lower than the base 1t is secondarily injected with the second resin. The second slide piece 78 is also shown in FIG. 30.
And the third slide piece 86 is lowered to close the one-step lower frame 1m of the base 1t, and the third resin is used for tertiary injection of the inside 1q of the frame. The second slide piece
The difference is that 78 is provided in a symmetrical arrangement with the first slide piece 70 described above, and other configurations are the same, so detailed description will be omitted. Figure 31 (1) (2), 32 (1) (2), 33 (1) (2), the above,
Each gate structure at the time of secondary and tertiary injection is shown. Figure 31 shows
At the time of primary injection, the second gate 91 communicating with the frame 1 m which is one step lower as in (1) is sealed by the first slide piece 70,
The third gate 93 penetrating the opening 1p as in (2) is also sealed by the first slide piece 70. FIG. 32 shows the second injection, and the second gate 91 is communicated with the lower frame 1 m by the second slide piece 78 as shown in (1), and the third gate 93 is shown as (2). It is sealed with a second slide piece 78. Figure 33 shows
At the time of the third injection, the second gate 91 is closed by the second injection as in (1), and the third gate 91 is closed as in (2).
The opening 1p is opened by the third slide piece 86 and communicates with the inside 1q of the frame.

The composite injection molding method according to claim 5 is
Inside the frame 1b, 1m lower than the base 1a, 1t of the main body 1
The secondary injection or the tertiary injection for filling e, 1q is made of a transparent resin or a resin of a color different from that of the bases 1a, 1t. In the case of a scuff plate made of transparent resin, it is possible to illuminate your feet during nighttime use by lighting the lamp from the lower frame 1b, 1m of the second gate 21 of 1m, or the opening 1d or 1p for the third gate 93. . When different color resins are used, the marks and characters can be easily recognized by filling around the raised marks and characters 1c and 1n.

The composite injection molding method according to claim 6 is
On the second slide piece 3 or the third slide piece 86 that closes the frames 1b and 1m lower than the base of the main body, the same marks / characters 2 as the first slide piece 2 or the second slide piece 78 are provided.
c, 2n are formed, and the embossed marks / characters formed by primary injection or secondary injection are fitted, or in the state where the marks / characters are pressed against each other, in the secondary injection or the tertiary injection, the inside of the frame 1
e, which protrudes from the surface filled with 1q, or forms embossed marks / characters in a recessed state. It is formed of a resin of a different color or different from the bases 1a, 1t of the main body. Marks and characters are made easier to recognize.

The composite injection molding method according to claim 7 is
The secondary injection or the tertiary injection that fills the insides 1e, 1q of the frame that is one step lower than the base of the main body is a different resin that is incompatible with the base of the main body, and is used during the primary injection or the secondary injection. A through-hole 1g is formed reaching the lower frame 1b, 1m, and is retracted by a required dimension to form a negative angle space a before the secondary injection or the tertiary injection. The second or third resin is injected into the negative angle space a to be integrated. The formation of the negative angle (undercut) space a is shown in FIG.
In 8, 19, by moving the slide bar 34 arranged on the movable side 20 to the left by a cylinder (not shown), the tapered pin 33 whose lower end is engaged with the inclined groove 35 of the slide bar 34 rises, The tip thereof comes into contact with the first slide piece 2 or the second slide piece 70 to form a through hole 1g, and the pin 33 is lowered by moving it to the right side to lower the frame 1 by one.
The pin 33 is configured to form a negative angle space a in b and 1 m, and the pin 33 is raised during the primary injection or the secondary injection, and is lowered during the secondary injection or the tertiary injection.

The composite injection molding method according to claim 8 is:
The heights of the embossed marks / characters 1c, 1n are made slightly lower than those of the bases 1a, 1t of the main body, and the transparent resin for secondary injection or tertiary injection is used for the embossed marks / characters 1c, 1n.
It is a form that covers the surface of. The surface height of the embossed marks / characters 1c, 1n is the same as the base 1a
Although it is assumed that the height is slightly lower than 1t, this is a precondition for covering the surface of the raised marks / characters 1c, 1n with a transparent resin for secondary or tertiary injection, which is slightly lower than the base 1a or 1t of the main body. Even if it is high, the first or second slide piece closes the lower frame 1b, 1m, and the raised marks / characters 1c, 1m
The same is done by injecting the second resin or the third resin in a form of covering the surface of n.

The composite injection molding method described in claim 9 is
Embossed marks / characters 1c, 1n surface height is the base of the body
Almost the same as 1a, 1t, and the second slide piece 3, 7
8 or the third slide piece 86 with the above embossed mark / character 1c,
The secondary injection and the tertiary injection are made of a transparent resin or a resin of a different color from the primary injection and a different color in the state where the surface of 1n is pressed. The surface heights of the embossed marks / characters 1c and 1n are substantially the same as those of the bases 1a and 1t of the main body, but the embossed marks / characters 1c are formed on the second slide piece 3, 78 or the third slide piece 86. It is a precondition of the form of pressing the surface of 1n,
This is to prevent secondary or tertiary injection resin from entering the surface of the embossed marks / characters 1c, 1n. In the case of the embodiment, it is optimal to compress about 0.5 mm by pressure contact.
For example, the second slide piece 3, 78 or the third slide piece 86 has the same marks / characters 2c, 2 as the embossed marks / characters 1c, 1n.
n (third slide piece not shown) is the base 1a of the main body,
When the height of the embossed marks / characters 1c, 1n is made higher than that of the base 1a, 1t, the embossed marks / characters 1c, 1n are formed on the base 1 of the main body.
It stands out from 1t. On the contrary, the marks / characters 2c, 2n of the second slide piece or the third slide piece are formed to project, and the surface heights of the embossed marks / characters 1c, 1n are the same as or lower than those of the bases 1a, 1t of the main body. In the case, it is recessed from the bases 1a and 1t of the main body. In addition, the second or third slide piece does not have any marks or letters formed and is a raised mark in a flat state.
When the surfaces of the letters 1c and 1n are pressed, the base 1a of the main body,
It has the same height as 1t.

The composite injection molding method according to claim 10 is
Without forming the press-cutting holes 1j in the frames 1b, 1m lower than the bases 1a, 1t of the molded product main body by the first or second slide pieces 2, 70, 78, or in the bases 1a, 1t of the main body,
First, the second slide piece 3, 78 or the third slide piece 86 is moved forward to move the first base 1a, 1h, 1t lower frame 1b, 1i, 1m and the frame 1e, 1q into The resin is primarily injected from the first gate 11 or the second gate 91 and integrally molded with the same resin. In injection molding only in this case, it is not necessary to use a complicated and expensive injection molding die, but as described above, a molding product in which one color or two colors is selected depending on the grade can be used with one mold It can be handled in the closed state. A molded product obtained by this composite injection molding method is used for decoration such as a scuff plate attached to an elevating step of a vehicle or a number frame attached to the rear side of an RV vehicle. Needless to say, it is used for decoration of injection-molded articles regardless of the vehicle. As shown in FIG. 34 (1), the alphabet characters, such as A, B, D, O ... Of the embossed marks / characters, are displayed on the second slide piece 3, 78 or the third slide piece 86. When injecting the second or third resin by pressing the surface of the mark / character with pressure, the resin flow path is not formed in the part of the mark / character by the above-mentioned configuration, and the resin is injected into the enclosed part. However, this notch makes the appearance unattractive and causes a problem. Therefore, as shown in FIG. 34 (2), the opening 40 that straddles the inside and the outside of the character surrounded by the embossed mark / character 1c (1n) in the primary injection is provided with a frame 1b (lower). 1m) so that both can communicate with each other, as shown in Fig. 34 (3).
The resin of 1e (1q) in the frame is opened by the secondary injection shown in
And then injected into the enclosed interior. Figure 35 (1),
(2) shows an embodiment thereof, in which the pin 41 forming the opening 40 is formed.
The lower end of the pin is engaged with the inclined groove 35 of the slide bar 34, and the opening 41 is formed by the rising of the pin 41 by the same operation as the formation of the space a of the negative angle described above, and the inside of the frame 1e ( 1q) and the inside surrounded by marks and letters are communicated and injected. Figure
36 (1) and 36 (2) are other embodiments replacing the slide bar 34, in which the block 42 forming the opening 40 is attached to the spring 43.
It is held by an elastic body such as, and lowered by a required dimension by the resin pressure of the secondary injection so that the inside of the frame 1e (1q) communicates with the inside of the mark / character.

FIG. 37 related to the description of the invention of claim 11 shows another embodiment in which two kinds of resins are injection molded.
The first slide piece 70 and the second slide piece 78 are arranged so as to face each other. According to this injection molding method, the volume of the mold becomes thin and the weight is reduced, so that the injection molding machine can be used as a small machine. The first and second slide pieces are the same as the operations of the first slide piece 70 and the second slide piece 78 for injection-molding the above-mentioned three kinds of resins, and therefore the description thereof will be omitted.

[0026]

According to the present invention having the above-described structure, the following effects are exhibited. (1) Two or three different types of injection molding can be performed by exchanging the mold and operating the slide piece while the mold is closed. Therefore, it is possible to reduce the cost of the equipment to a large extent, because it is possible to use a single mold that requires two molds or three molds for either the fixed side or the movable side. (2) Mold replacement time is not required, and the cavity shape can be changed while the mold is closed, shortening the molding cycle. Therefore, the change in mold temperature is reduced,
Moreover, it becomes easy to maintain molding conditions. Further, for this reason, the molding efficiency is improved and the total cost can be reduced. (3) Since the molded product does not need to have stickers or hot stamps on which marks and characters are printed due to the integration of different types of resin, it is possible to save equipment and work processes for stickers and sticking jigs and hot stamps. In addition, the molded product can be provided at low cost, and peeling does not occur. (4) Since the first slide piece and the second slide piece are arranged so as to face each other, the mold volume of the injection molding machine is thin and the weight is reduced. Therefore, the injection molding machine can be used as a small machine.

[Brief description of drawings]

FIG. 1 is a plan view of a molded product, (2) is a right half center lateral enlarged sectional view of the molded product, and (3) is a right half center longitudinal enlarged sectional view of the molded product.

FIG. 2 is a principle view of the steps of the injection molding method, in which (1) is a state diagram when the first slide piece is lowered and primary injection is performed, and (2) is the first slide piece is raised. (3) is a state diagram when the first slide piece is retracted, (4) is a state diagram when the second slide piece is lowered and held, and then secondary injection is performed.

FIG. 3 is a cross-sectional view taken along the line AA of FIG. 7 when performing the primary injection after the first slide piece is lowered and held.

FIG. 4 is a cross-sectional view taken along the line AA of FIG. 7 when the first slide piece is raised.

5 is a sectional view taken along the line D-D of FIG. 7 when the first slide piece is retracted.

6 is a sectional view taken along line AA of FIG. 7 at the time of secondary injection after the second slide piece is lowered and held.

FIG. 7 is a view on arrow Y of FIG.

FIG. 8 is a view on arrow Z in FIG.

9 is a sectional view taken along line BB of FIG. 7.

10 is a sectional view taken along line CC of FIG.

FIG. 11 shows the engagement state of the rail and the second slide piece,
FIG. 4 is a sectional view taken along line EE of FIG.

12 is a sectional view taken along line FF of FIG.

FIG. 13 is a plan view of an injection molding die.

FIG. 14 is a sectional view of a main part of an injection molding die.

FIG. 15 is an operation state diagram of the first slide piece with respect to the operation of the slider.

[FIG. 16] (1) is a detailed view of the gate portion, (2) is FIG. 16 (1)
16 is an enlarged cross-sectional view taken along line G-G, and (3) is an enlarged cross-sectional view taken along line H-H in FIG.

17 is an enlarged cross-sectional view of a main part around the gate piece in FIG. 14.

FIG. 18 is an explanatory diagram of a negative angle structure on the movable side.

19 is an enlarged view of a main part of FIG. 18.

FIG. 20 is a detailed view of a molded product and a gate portion according to the second embodiment.

21 is an enlarged cross-sectional view taken along line G2-G2 of FIG. 20.

22 is an enlarged cross-sectional view taken along line H2-H2 of FIG.

23 is a cross-sectional view taken along the line AA of FIG. 7 at the time of primary injection of the second embodiment.

FIG. 24 is a cross-sectional view taken along the line AA of FIG. 7 when the first slide piece of the second embodiment is retracted.

FIG. 25 is a cross-sectional view taken along the line AA of FIG. 7 at the time of secondary injection after the second slide piece of the second embodiment is advanced and held.

FIG. 26 is a process principle diagram of a composite injection molding method which is a third embodiment, (1) is a state diagram when the first slide piece is advanced to perform primary injection, and (2) is a first slide piece. After the retreat, the second slide piece is advanced to perform the secondary injection, and (3) is the state diagram when the second slide piece is retracted and the third slide piece is advanced to perform the third injection. .

FIG. 27 is a partial bottom view of the injection molding die that is the third embodiment.

FIG. 28 is a cross-sectional view taken along the line AA of FIG. 27 when the primary injection is performed after the first slide piece is moved forward and held.

29 is a cross-sectional view taken along the line AA of FIG. 27 when the second slide piece is moved forward and held, and then the secondary injection is performed after the first slide piece is retracted.

FIG. 30 is a cross-sectional view taken along the line AA of FIG. 27 when the third slide piece is advanced and held after the second slide piece is retracted, and then the third injection is performed.

[Fig. 31] (1) shows the second gate at the time of primary injection, and is a state diagram in which it is blocked by the first slide piece, and (2) is a state diagram in which the push-out hole of the third gate is also similarly blocked. is there.

[FIG. 32] (1) is a state diagram showing the second gate at the time of secondary injection, in which the second slide piece is opened, and (2) is a state diagram in which the third gate is closed.

[FIG. 33] (1) shows a second gate at the time of tertiary injection, and is a state diagram in which it is closed by secondary injection, and (2) is a state diagram in which the third gate is opened by a third slide piece. .

FIG. 34 shows another embodiment, in which the inside surrounded by marks and characters is filled, (1) is an explanatory diagram of marks and characters,
(2) is an explanatory view at the time of primary injection, and (3) is an explanatory view at the time of secondary injection.

35 (1) is an explanatory view of the mold structure in the embodiment of FIG. 34, and (2) is a sectional view taken along the line JJ of FIG. 35 (1).

36 (1) is an explanatory view of another mold structure in the embodiment of FIG. 34, and (2) is a sectional view taken along the line KK of FIG. 36 (1).

FIG. 37 is a diagram of another example of injection molding two kinds of resins.

[Explanation of symbols]

10 Fixed side 20 Movable side 1 Molded product 1a, 1h, 1t Base (of molded product body) 1b, 1i, 1m Lower frame 1c, 1n Embossed mark / character 1e, 1q Frame 1d, 1p Opening 1g Through hole 1j Push-out hole 11 First gate 21, 91 Second gate 93 Third gate 12 First sprue (for first resin) 13 Second sprue (for second resin) 14 Third sprue ((third resin 2) 2A, 70 1st slide piece (possible to move back and forth in the die opening direction and the direction orthogonal to the die opening direction) 3, 3A, 78 2nd slide piece (die opening direction only, die opening direction and die opening) 86 Third slide piece (possible to move in and out of the mold opening direction and the direction orthogonal to the mold opening direction) 2a, 4a, 75, 83 Dovetail grooves 2b, 5a, 71, 79 Dovetail guide 2c Mark / Character 2d Positioning pin 20a Fitting hole 22 Split side faces 23, 90, 92 Gate piece 24 Ejector plate 25 Rod 26 Groove 27 Lupler 28 Base 29 Ejector pin 30 Collar 31, 72, 80, 87 Cam 32 Movable side plate 33 Tapered pin 34 Slide bar 35 Inclined groove 40 Opening 41 Pin 42 Block 43 Spring 4, 74, 82 Slide piece 5, 6, 76, 84 Slider 61, 77, 85 Rail 8 Stopper a Negative space S cylinder

─────────────────────────────────────────────────── ─── Continuation of the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) B29C 45/00-45/84

Claims (11)

(57) [Claims] 1. A composite injection molding method comprising integrally molding a base of a molded article main body and a resin of different color with a different color by means of an injection molding die having a fixed side and a movable side.
On the fixed side, the base is connected via a first gate, the first sprue for the first resin is connected to the frame one step lower than the base, and the base is connected to the inside of the frame one step lower via the second gate. And a second sprue for the second resin that forms a frame one step lower than the base of the base, and is capable of advancing and retracting in the mold opening direction and in a direction orthogonal to the mold opening direction. And a second slide piece capable of forming a cavity in the frame by closing a frame lower than the base by one step and moving back and forth only in the mold opening direction. The second gate, which penetrates the opening of the lower frame and communicates with the frame, is arranged in a submarine shape that communicates with the second sprue and is formed on a gate piece that can be projected by an ejector plate. When one slide piece moves forward, the second game When the second slide piece is moved forward, the second gate is connected to the second gate, the first resin is injected from the first sprue, and the base of the main body and the frame one step lower than the base are primary-injected. A composite injection molding method, characterized in that a series of operations up to secondary injection for injecting a resin and filling a frame of a frame one step lower than the base is performed in a mold closed state. 2. A composite injection molding method in which a base of a molded article body and a resin of a different color are integrally molded on a base of a molded article main body by an injection molding die having a fixed side and a movable side, wherein the fixed On the side, a first sprue for the first resin, which communicates with the base having a push-cut hole through the first gate, and a second sprue for the second resin, which communicates with the push-cut hole through the second gate. And a first slide piece capable of forming a press-cutting hole and moving forward and backward in the mold opening direction and a direction orthogonal to the mold opening direction, and closing the press-cutting hole to insert the base into the base. A second slide piece that forms a cavity of a frame that is one step lower and that can advance and retreat only in the mold opening direction is provided, and on the movable side, a second slide piece that penetrates the push-out hole and communicates with the inside of the cavity is formed. Two gates are formed in the shape of a submarine communicating with the second sprue. In the arrangement, it is formed in a gate piece that can be projected by an ejector plate, and the second gate is closed when the first slide piece is moved forward, and is connected to the second gate when the second slide piece is moved forward. A series of processes from one injection of resin to the primary injection of the base of the main body having the press-cut hole, and the injection of the second resin from the second sprue to the secondary injection of filling the frame in the press-cut hole one step lower than the base. The composite injection molding method is characterized in that the above-mentioned operation is performed in a mold closed state. 3. A composite injection molding method in which a base of a molded article body and a part of the base are integrally molded with a resin of different color by an injection molding die having a fixed side and a movable side. On the side, a first sprue for the first resin that communicates with the base of the main body through the first gate, and a second sprue for the second resin that communicates with the frame that is one step lower than the base through the second gate, A third sprue for the third resin, which communicates with the inside of the frame one step lower through the third gate, is provided, and the frame one step lower than the base of the main body is pushed off, and the mold opening direction and the direction orthogonal to the mold opening direction And a first slide piece capable of advancing and retreating to form a cavity of a frame one step lower than the base, and capable of advancing and retracting in a mold opening direction and a direction orthogonal to the mold opening direction symmetrical with the first slide piece. Second slide piece and one step lower than the base of the main body A third slide piece that closes the frame to form a cavity in the frame and that can advance and retreat only in the mold opening direction is provided, and the movable side is connected to a frame that is one step lower than the base. The two gates are arranged in the shape of a submarine that communicates with the second sprue, and are formed on a gate piece that can be projected by an ejector plate, and the third gate that communicates with the frame has a submarine that communicates with the third sprue. Formed in a gate piece that can be protruded by an ejector plate, and seals the second gate and the third gate when the first slide piece moves forward, and communicates with the second gate when the second slide piece moves forward Along with that, the third gate is sealed and communicated with the third gate when the third slide piece moves forward, the first resin is injected from the first sprue, and the base of the main body is primary-injected. The second resin is injected from the sprue and the second lower injection of the frame is performed, and the third resin is injected from the third sprue and the third injection is performed to fill the inside of the lower frame of the frame. A composite injection molding method, characterized in that it is carried out as it is. 4. The composite injection molding method according to claim 1, 2 or 3, wherein marks or characters are formed on the surface of the first or second slide piece forming a frame one step lower than the base of the main body. . 5. The composite injection molding method according to claim 1, wherein the secondary or tertiary injection is a transparent resin or a resin of a different color from the base of the main body. 6. A float formed by primary or secondary injection by forming the same marks and characters as those of the first or second slide piece on the second or third slide piece that closes the frame one step lower than the base of the main body. 6. The composite injection molding method according to claim 4 or 5, characterized in that the marks or characters that are put out are fitted or the secondary injection or the tertiary injection is performed while the marks and characters are pressed against each other. 7. The secondary or tertiary injection is performed with a resin incompatible with the base of the main body, and is communicated with and integrated with a negative angle space formed in a frame one step lower than the base. 7. The composite injection molding method according to claim 1, 2 or 3 or 4 or 5 or 6. 8. The surface height of the raised marks / characters is formed slightly lower than that of the base of the main body, and the surface of the marks / characters is covered with a secondary or tertiary injection transparent resin. The composite injection molding method according to claim 4 or 5. 9. The surface height of the embossing marks / characters is formed to be substantially the same as the base of the main body, and the surface of the embossing marks / characters is pressed against the surface by the second or third slide piece. The composite injection molding method according to claim 4 or 5, wherein secondary or tertiary injection is performed. 10. The first resin is injected from the first sprue in a state in which the second or third slide piece is moved forward, and inside the base and push-out hole of the main body, or lower than the base of the main body and inside the frame. 5. The composite injection molding method according to claim 1, characterized in that and are molded by primary injection. 11. A composite injection molding method for integrally molding a base of a molded article body and a resin of a different color with a different color by an injection molding die comprising a fixed side and a movable side,
On the fixed side, the base is connected via a first gate, the first sprue for the first resin is connected to the frame one step lower than the base, and the base is connected to the inside of the frame one step lower via the second gate. And a second slide for the second resin for forming a frame one step lower than the base, the first slide piece capable of advancing and retracting in the mold opening direction and the direction orthogonal to the mold opening direction,
Forming a cavity in the frame by closing the frame one step lower than the base, the mold opening direction and a second slide piece capable of advancing and retreating in a direction orthogonal to the mold opening direction are arranged to face each other, On the movable side, a second gate penetrating through the opening of the frame one step lower than the base and communicating with the frame of the one step lower frame is formed in a submarine shape communicating with the second sprue. It is formed into a gate piece that can be projected by a plate, and the second gate is sealed when the first slide piece moves forward and communicates with the second gate when the second slide piece moves forward, and the first resin is injected from the first sprue. Then, the base of the main body and a frame one step lower than the base are primarily injected, and a series of operations up to the secondary injection in which the second resin is injected from the second sprue to fill the frame of the frame one step lower than the base, Mold closed Composite injection molding process, which comprises carrying out remains.