JP3343792B2 - Two-layer foam injection molding machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a two-layer foam molding of a surface material, such as an interior panel of an automobile, comprising a foam layer having a cushioning property on one surface of a core material made of a hard resin and a skin layer on the surface. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a two-layer foam injection molding apparatus for molding an article by one injection molding, and more particularly, to an apparatus having a fixed plate, a movable plate, and a rotary plate, which are simultaneously molded by two sets of dies.

[0002]

2. Description of the Related Art A two-layer injection molding apparatus capable of injection-molding a two-layer molded product in which two kinds of different materials or resin materials of different colors are superposed is disclosed in Japanese Patent Publication No. 3-51207.
It is known as disclosed in Japanese Patent Publication No.

In the two-layer injection molding apparatus disclosed in the publication, a rotary plate is provided between a fixed plate and a movable plate, and primary molding is performed between the fixed plate and the rotary plate and between the rotary plate and the movable plate. And secondary molding. That is, after a primary molded product is obtained by injection molding into a primary mold between the fixed plate and the rotary plate, the rotary plate is rotated by 180 °, and the inside of the secondary die between the rotary plate and the movable plate is formed. In the state where the primary molded product is located, injection molding is performed on a secondary mold to obtain a two-layer secondary molded product.

As disclosed in Japanese Patent Publication No. 3-51207, a mold clamping mechanism of such a two-layer injection molding apparatus is jointly fastened via a tie bar with a fixed platen, a rotary platen and a movable platen closed. Type is used.

[0005]

However, the above-mentioned 2
In the case of a layer foam molded product, it is necessary to open the mold at a predetermined interval between the rotating plate and the movable plate for foaming. However, there is a problem in that the secondary mold is opened and the primary mold is opened at the same time, so that control becomes impossible.

The present invention has been made in view of the above-mentioned problems of the prior art, and an object of the present invention is to perform ordinary injection molding using a primary mold and a secondary mold. Another object of the present invention is to provide a two-layer foam injection molding apparatus capable of performing foam injection molding by opening a mold with a secondary mold.

[0007]

A two-layer foam injection molding apparatus according to the present invention for solving the above-mentioned problems comprises a fixed plate provided between two sets of opposed injection units, and a plurality of protruding members provided from the fixed plate. A tie bar, a movable plate that is guided by the tie bar and is connected to a second opening / closing cylinder and that can be opened and closed; a second locking means for the tie bar provided on the movable plate; and between the movable plate and the fixed plate. An openable / closable turntable provided and guided by the tie bar and connected to a first open / close cylinder;
A first locking means for the tie bar provided on the rotating plate, a mold clamping cylinder for moving the tie bar forward and backward with respect to the fixed plate, and a mold opening cylinder for opening a predetermined interval between the movable plate and the rotating plate. Preferably, the first locking means and the second locking means have an elastically deformable member for gripping the tie bar and are hydraulically operated.

[0008]

With the first opening and closing cylinder and the second opening and closing cylinder, the fixed plate, the rotary plate and the movable plate are closed, and the second plate of the movable plate is
When the tie bar is integrated with the tie bar by the locking means and the tie bar is pulled into the fixed plate by the mold clamping cylinder, the fixed plate, the rotating plate and the movable plate are jointly fastened. In this state, normal injection molding for injecting a predetermined resin into the primary mold and the secondary mold is performed. Then, when the first lock means of the rotary disc is integrated with the tie bar and the second lock means of the movable disc is released, the mold clamping cylinder clamps the mold only between the rotary disc and the fixed disc. And
The mold is opened at a predetermined interval by a mold opening cylinder between the movable platen and the rotary platen. In this way, by switching between the first lock means and the second lock means, the primary mold and the secondary mold are jointly tightened and switched to the primary mold alone, and the secondary mold for foaming is switched. The mold opens smoothly.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a longitudinal sectional side view of a front closed state of a two-layer foam injection molding apparatus of the present invention, and FIG.
FIG. 3 is a sectional view showing the structure and operation of the locking means.

In FIG. 1, a first injection unit 2, a fixed platen 3, a rotary plate 4, a movable plate 5, and a second injection unit 6 are arranged on a common bed 1 in order from the right side of the drawing.

The first injection unit 2 includes a slide rail 11
It is slidably mounted on the top, and the whole is moved to the left in the drawing by the hydraulic cylinder during injection. Rotating disk 4 and moving disk 5
Is configured to be slidable on the slide rail 12 and through a tie bar 13 protruding from the fixed platen 3. One end of the tie bar 13 is a piston 14 and forms a mold clamping cylinder 16 together with the cylinder 15 in the fixed platen 3. An end plate 17 is fixed to the other end of the tie bar 13, and a lower portion of the plate 17 is slidable on the slide rail 12. The second injection unit 6 is slidably mounted on a slide rail 18, and the entirety moves rightward in the drawing at the time of injection.

A first opening / closing cylinder 20 is interposed between the rotating plate 4 and the fixed platen 3. The rotating plate 4 opens and closes with respect to the fixed platen 3 by extending or shortening the first opening / closing cylinder 20. Similarly, a second opening / closing cylinder 21 is provided between the movable platen 5 and the fixed platen 3, and the movable platen 5 opens and closes with respect to the fixed platen 3 by extending or shortening the second opening / closing cylinder 21.

Further, the first tie bar 13 is provided between the turntable 4 and the tie bar 13.
A lock means 22 is interposed, and a second lock means 23 is interposed between the movable plate 5 and the tie bar 13. By these lock means 22, 23, the rotary plate 4 and the movable plate 5 are separately integrated with the tie bar. Or move freely.

Further, a mold opening cylinder 24 is interposed between the rotary platen 4 and the movable platen 5. That is, the micrometer head 26 is attached to the tip of the rod 25 protruding from the turntable 4.
Is screwed, and the tip of the rod 24a of the mold opening cylinder 24 abuts on the micrometer head 26. When pressure oil is introduced into the cylinder side chamber of the mold opening cylinder 24 and the rod extends to the stroke end, the movable platen 5 opens a predetermined distance. This predetermined distance can be adjusted by rotating the micrometer head 26.

FIG. 2 shows the positional relationship among the tie bar 13, the first opening / closing cylinder 20, the second opening / closing cylinder 21, and the mold opening cylinder 24 (rod 25). Four tie bars 13 are arranged at four corners, two first opening / closing cylinders 20 and second opening / closing cylinders 21 are arranged on diagonal lines crossing each other, and two bar bodies 25 are provided with respect to the center O. They are arranged symmetrically.

Returning to FIG. 1, a primary die 30 is mounted between the fixed platen 3 and the rotary plate 4, and a secondary die 31 is mounted between the rotary plate 4 and the movable plate 5. ing. In particular, the turntable 4 has a rotating body 33 rotatable about a shaft 32. A male mold 30a of the primary mold 30 and a male mold 31a of the secondary mold 31 having the same shape are attached to the rotating body 33. Have been. The rotating body 33 is a rotary actuator 34
, The rotation of the male mold 30a of the primary mold 30 and the male mold 31a of the secondary mold 31 are switched. A primary molding cavity 35 is formed in the primary mold 30, and a secondary molding cavity 36 is formed in the secondary mold 31. The secondary molding cavity 36 is wide for injection onto the primary molding layer.
Further, the secondary molding cavity 36 is further opened by the above-described mold opening cylinder 24 so that the secondary molding layer injected onto the primary molded product foams.

In FIG. 3, the molded product is taken out of the secondary mold 31 and the rotating body 33 of the rotating disk 4 is rotated by 180 °.
Due to the rotation, the rotary platen 4 and the movable platen 5 are fully opened as shown by the extension of the first opening / closing cylinder 20 and the second opening / closing cylinder 21. When the first opening / closing cylinder 20 and the second opening / closing cylinder 21 are shortened, the fixed platen 3, the rotary platen 4, and the movable platen 5 are fully closed as shown in FIG.

Next, the structure and operation of the preferred first lock means 22 and second lock means 23 will be described with reference to FIG. FIG. 4A is a sectional view in a locked state, and FIG. 4B is a sectional view in an unlocked state.

In FIG. 4A, a sleeve 41 for the tie bar 13 is fixed to the rotating plate 4 or the movable plate 5 via flanges 42 at both ends. The sleeve 41 has an inner diameter that is tight against the tie bar 13, and is usually integrated with the tie bar 13 by grasping the tie bar 13. Further, the sleeve 41 is elastically deformable, a seal 43 is provided between the sleeve 41 and both end flanges 42, a seal 44 is provided between both end flanges 42 and the tie bar 13, and a pressure oil chamber 45 is formed. ing. Therefore, port 46
When the pressurized oil is supplied from, as shown in FIG. 4B, the sleeve 41 expands to form a gap between the sleeve 41 and the tie bar 13.
The rotation of the turntable 4 or the movable platen 5 with respect to the tie bar 13 is performed smoothly. When pressure oil is drained from port 46, FIG.
The state returns to the locked state of FIG. The locking means 22, 23
Can form a locked state at any position of the tie bar 13.

Next, the molding process of a two-layer foam molded article by the above-described two-layer foam injection molding apparatus will be described with reference to FIG. FIG. 5A shows a preparation step, and FIGS. 5B to 5D show a repetition step.

In FIG. 5 (a), at least the rotating plate 4 is closed with respect to the fixed plate 3, and the first injection unit 2 injects a hard resin into the primary cavity 35 of the primary mold 30.
A primary molded product of the core material is formed on the male mold 30a.

In FIG. 5 (b), the rotary plate 4 and the movable plate 5 are opened as shown by the arrow a so as to be fully opened, and the rotating body 33 of the rotary plate 4 is rotated by 180.degree. Position it toward the side mold. Then, the rotary platen 4 and the movable platen 5 are closed as shown by an arrow b to bring them into a fully closed state.

In FIG. 5 (c), the tie bar 13 and the movable platen 5
Are integrated. At this time, the first locking means 22 of the turntable 4 remains in the unlocked state. Then, pressure oil is supplied to the rod side chamber of the mold clamping cylinder 16 and the piston 14
Is pulled in the direction of the arrow c, the rotary plate 4 and the movable plate 5 are fastened to the fixed plate 3 together. In this state, the first
The injection of the injection unit 2 and the second injection unit 6 is performed. Then, a new core material is formed in the primary mold 30, and a foamed resin is laminated on the core material in the secondary mold.

In FIG. 5D, when the first locking means 22 of the rotary platen 4 is changed from the unlocked state to the locked state and the second locking means 23 of the movable platen 5 is changed from the locked state to the locked state, the fixed platen 3 On the other hand, only the turntable 4 is switched to the single mold clamping in which the mold is clamped by the mold clamping cylinder 16. When the rod 24a of the mold opening cylinder 24 is extended in the direction of arrow d, the tip of the rod 24a hits the micrometer head 26, the movable platen 5 moves to the left in the drawing, and the mold is opened by the distance ε. Then, foaming of the foamed resin is performed, and a laminate formed of a surface material having a surface skin layer and an inner foam layer and a core is formed. When the laminated molded body cools, the mold clamping cylinder 16 is released, and the first locking means 22 is released.
Is also unlocked.

Then, the first opening / closing cylinder 20 and the second opening / closing cylinder 21 are extended to the fully opened state in FIG. Next, the laminated molded body was taken out, and the rotating body 33 of the rotating disk 4 was set to 1
Rotate 80 °. Next, the first opening / closing cylinder 20 and the second opening / closing cylinder 21 are shortened to the fully closed state in FIG. This state is the state shown in FIG.
(C) → The molding cycle of FIG. 5 (d) is repeated.

[0026]

The two-layer foam injection molding apparatus according to the present invention has a first
By switching between the lock means and the second lock means, the primary mold and the secondary mold are switched from co-tightening to the primary mold alone, and the secondary mold for foaming is opened smoothly. Therefore, the two-layer foam molding can be continuously produced by one injection molding apparatus. Also, the first
When the lock means and the second lock means having an elastic deformation member for gripping the tie bar are used, the tie bar can be gripped at an arbitrary position, and troublesome adjustment such as grip position adjustment accompanying a change in mold thickness is unnecessary. Can quickly respond to setup changes.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional side view of a front closed state of a two-layer foam injection molding apparatus of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a view showing the structure and operation of a locking means.

FIG. 4 is a vertical sectional side view of the two-layer foam injection molding apparatus of the present invention in a fully opened state.

FIG. 5 is an operation diagram of the two-layer foam injection molding apparatus of the present invention.

[Explanation of symbols]

 2 First injection unit 3 Fixed plate 4 Rotary plate 5 Movable plate 13 Tie bar 16 Mold clamping cylinder 20 First opening / closing cylinder 21 Second opening / closing cylinder 22 First locking means 23 Second locking means 24 Mold opening cylinder 41 Sleeve (elastic deformation member) )

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B29C 45/00-45/84

Claims (2)

(57) [Claims] 1. A fixed plate provided between two sets of opposed injection units, a plurality of tie bars protruding from the fixed plate, and connected to a second opening / closing cylinder guided by the tie bar to be openable and closable. A movable plate, a second locking means for the tie bar provided on the movable plate, and an openable / closable rotary plate provided between the movable plate and the fixed plate and guided by the tie bar and connected to a first opening / closing cylinder First locking means for the tie bar provided on the rotary plate, a mold clamping cylinder for moving the tie bar forward and backward with respect to the fixed plate,
A two-layer foam injection molding apparatus including a mold opening cylinder that opens a predetermined distance between the movable platen and the rotary plate. 2. The two-layer foam injection molding apparatus according to claim 1, wherein said first locking means and said second locking means have an elastically deformable member for gripping said tie bar and are hydraulically operated.