JPH072342B2 - Film insert injection molding machine - Google Patents

Description

TECHNICAL FIELD The present invention relates to a film insert injection molding machine.

[Prior Art] Conventionally, for example, a resin film in which designs such as letters, symbols, pictures, and patterns are printed on the back side and the designs are transparently displayed on the exposed side, and metal films in which the designs are formed on the exposed side, etc. A thin decorative film with a thickness of about 0.3 mm or less is set as an insert film in the cavity formed on the mating surface of the fixed mold and the movable mold, and a resin molding material with a certain thickness is integrally formed on the back surface of the cavity. When forming a formed product, a so-called film insert molded product, a horizontal opening injection molding machine or a vertical opening injection molding machine has been used.

[Problems to be Solved by the Invention] However, when a horizontal opening injection molding machine is used, since the cavity surface for setting the insert film is in the vertical position, the insert film is
There is a need for a means of securely holding in place. As the means, for example, static electricity is applied to the insert film in advance by a static electricity generator or the like, and the electrostatic action is used to adsorb to the cavity surface, or an adhesive is applied to a part of the exposed surface of the insert film. A method of adhering to the cavity surface is used.

In the case of utilizing the static electricity, there arises a problem that the insert film falls off from a fixed position or a position shift occurs due to vibration when the movable mold moves to the fixed mold side during mold clamping. Therefore, the defective rate of the molded product was as high as about 20%.

In the case of using an adhesive, a molding material may be injection-molded on the back surface of the insert film, and the design display surface of a molded product integrally molded with the insert film may be soiled by the adhesive. Therefore, although the side-opening injection molding machine is used at the trial production stage, it has not been put to practical use for mass production.

Therefore, using a vertical opening type injection molding machine, the insert film is placed horizontally on the cavity surface of the lower mold, and the molding material is injection-molded on the back surface side of the lower mold to form an integrally molded product. It is also possible to push it up by the ejector part and take it out from the cavity surface of the lower mold.

However, in this case, the tip of the ejector pin of the ejector portion abuts the exposed surface, which is the design surface of the insert film, and damages the exposed surface of the insert film, and the molten molding material injected from the lateral position of the cavity It penetrates between the exposed surface of the insert film and the cavity surface and adheres to the exposed surface, which hinders its practical use.

It is an object of the present invention to provide a film insert injection molding machine that solves the above conventional problems.

[Means for Solving the Problems] The film insert injection molding machine of the present invention comprises a lower mold having a mounting surface on which a cavity is formed on a mating surface at a horizontal position and the insert film is mounted on the cavity. A gate portion provided with a gate passage for injecting a molding material toward the back side of the insert film mounted on the mounting surface of the cavity through the gate passage; and a molded product integrally molded with the insert film. A holding mechanism, which is cured in the gate passage of the gate portion when the mold is opened and is held by a molding material portion connected to a part of the molded article, and an ejector pin movably arranged in the gate passage of the gate portion, An upper die having an ejector portion for pushing out the molded product held by the holding mechanism downward to release the holding of the holding mechanism; To.

One of the upper die and the lower die may be a fixed die and the other may be a movable die, which can be relatively moved.

The lower mold is a mounting surface for mounting the insert film of the cavity formed on the mating surface at the horizontal position together with the upper mold,
For example, a flat shape can be used.

The upper mold is. It has a gate part, a holding mechanism, and an injector part.

The gate part injects the molten molding material toward the back side of the insert film mounted on the mounting surface of the cavity. For example, a cold runner type upper tunnel gate or a hot runner type upper gate. It is possible to use a passage through which the molding material flows, such as a gate, which is connected to the hot runner portion of the mold.

The holding mechanism, during the mold opening of the molded product integrally molded with the insert film by the molding material injected into the cavity from the gate portion, until the upper mold and the lower mold reach a preset mold opening position. , Holds the upper mold. This holding mechanism is formed, for example, in a cold runner type upper gate tunnel gate portion formed in an upper mold, or in a hot runner passage in which the hot runner type upper mold gate is bent. In the state in which the molten molding material is injected into the cavity and hardened, and a part of the molding material remaining in the above-mentioned passage of the upper mold maintains a certain hardness. The one formed by connecting to the molded product to form a connecting part and the Z pin having a so-called Z-shaped gap at the tip of the ejector pin in contact with the cavity, and a part of the injected molding material is integrated with the molded product. It is possible to use a device in which the Z-shaped gap is filled in, and the Z pin and a part of the molded product are connected and held.

The ejector portion is configured to push down the molded product held by the holding mechanism in the upper mold to forcibly release the holding of the holding mechanism. The ejector parts are respectively held by the upper molds and moved up and down so that the tips come into contact with the molding material filled on the side opposite to the exposed surface which is the design display surface of the insert film, that is, the back surface side of the insert film. The ejector pin that is held movably, the ejector plate that is held on the back side of the upper mold opposite to the cavity surface so that it can move up and down, the stopper member that limits the movable range of the ejector plate, and one end of which is connected to the ejector plate. It can be composed of a plurality of ejector pins that push the product downward at the other end, and a biasing member that biases the ejector plate downward when the upper die moves upward. A plurality of ejector pins can be used. Further, it is preferable that at least one of the plurality of ejector pins has a Z-shaped notch at its tip and forms a part of the above-described holding mechanism. Further, the biasing member biases the ejector pin against the ejector plate until the upper mold and the lower mold are separated by a certain distance when the mold is opened. It is possible to use a structure having a structure capable of releasing the above-mentioned urging to the. Further, by using the urging member, the mold opening distance between the upper mold and the lower mold can be sufficiently taken, and it is easy to set the insert film on the mounting surface, the operation of taking out the molded product, the maintenance of the cavity surface, etc. It has the effect of hardening such as being easy to do.

[Operations and Effects] According to the film insert injection molding machine of the present invention, the upper mold for forming the cavity on the mating surface at the horizontal position and the lower mold having the mounting surface for mounting the insert film on the cavity are in the mold open state. In the case of, the insert film is placed horizontally with respect to the placement surface with the exposed surface side serving as the design display surface placed and the back surface side facing upward.
After the upper mold and the lower mold are closed, the molding material is injected toward the back surface side of the insert film through the curved gate passage formed in the upper mold. Then, the insert film is pressed against the mounting surface from the back surface side by the pressure of the injection of the molding material, and is securely held at a predetermined set position. Therefore, the molding material is
A molded product that is integrally molded with the insert film that is filled between the insert film and the placement surface, that is, does not enter the exposed surface side of the insert film and is filled in the cavity space on the back surface side and has no dirt on the design display surface To be done. Then, when the mold is opened, the molded product is preset in a state in which the molded product is held in the upper mold by a holding mechanism that is hardened in the bent gate passage of the gate portion and held by a molding material portion connected to a part of the molded product. The ejector pin, which is held by the upper mold and is arranged to be able to advance and move in the bent gate passage when the die reaches the opened position, is held in the holding mechanism by moving to the bent gate passage. Further, the holding of the holding mechanism is released by abutting the portion integrally formed on the back surface of the insert film of the molded product and pushing it downward. As a result, the insert film inserted on the lower end side of the molded product moves forward to the bent gate passage from the state held in the upper mold because the exposed surface, which is the design display surface, is located on the side opposite to the ejector section. The design display surface is not damaged when it is pushed downward by the ejector pin of the ejector part that is arranged as possible.

Further, it is possible to eliminate the problem that the insert film is vertically set on the setting surface of the cavity as in the case of using the horizontal opening injection molding machine.

[Example] (Example 1) The film insert injection molding machine of Example 1 of the present invention is of a vertically open type, and as shown in Figs. It consists of an upper mold 2 of the cold runner type that closes and opens the mold with respect to the lower mold 1. In the mold closed state, the lower mold 1 and the upper mold 2 each have a lower cavity surface 40 and an upper cavity surface 42 provided on the lower mating surface 3a and the upper mating surface 3b in the horizontal position, respectively. 4 is forming.

The lower mold 1 has a flat mounting surface 41 on which the insert film 8 is mounted on the lower cavity surface 40. Further, the lower mold 1 has an insertion hole 10 having an engaging portion 10a for engaging a biasing member 227 described later, a wall surface 202a forming a horizontal passage 202 of the tunnel gate portion 20, and a nozzle touch portion 201. Concave wall 2
01a and are provided. The lower end of the lower die 1 is connected to and held by the lower die mounting plate 11.

The upper mold 2 is of the cold runner type and has a holding mechanism 21.
And an ejector portion 22 and the upper cavity surface 42. Further, the upper end of the upper mold 2 is connected and held via a spacer member 23 to an upper mold mounting plate 24 mounted interlockingly with a movable part of a mold clamping device (not shown). This makes upper mold 2
Is configured so that the upper mating surface 3b can be moved in a direction of coming into contact with and leaving the lower mating surface 3a of the lower mold 1 by interlocking with the upper mold mounting plate 24 at the time of mold closing and mold opening. .

The tunnel gate portion 20 is provided on the mounting surface of the cavity 4 41
A passage for injecting the molten molding material is formed toward the back surface 81 side of the insert film 8 placed on. When the mold is closed (see FIG. 1), the tunnel gate portion 20 forms a horizontal passage 202 communicating with the nozzle touch portion 201 and a throttle portion extending obliquely upward from the horizontal passage 202 via a reservoir chamber 203. It is formed by an inclined passage 204 and a vertical passage 20 that intersects the inclined passage 204 at an acute angle and opens to the upper cavity surface 42.

The holding mechanism 21 uses the molded product 4A formed in the cavity 4
It is kept in a state of being adhered to the upper cavity surface 42 of the upper mold 2 until it reaches a preset mold opening position.
It comprises a first holding part 210 and a second holding part 211. The first holding part 210 has a substantially inverted V-shaped space formed by the inclined passage 204 and the vertical passage 205 forming the tunnel gate portion 20 when the mold is closed, and when the cavity 4 is filled with the molding material. , A rod-shaped body (molding material) 4a existing before and after the intersection position P1 between the two passages 204 and 205 and filled in the cavity 4 and integrated with the molded product 4A after molding. . The second holding part 211 is located on the upper cavity surface 42 of the upper mold 2 when the mold is closed, and the second ejector pin 225 having a Z-shaped cutout P2 connected to the cavity 4 and the cutout P2 are filled. It is composed of a part integrated with the molded product 4A in the cavity 4.

The ejector portion 22 is for pushing down the molded product 4A held by the upper mold 2 by the holding mechanism 21 to release the held state, and the rear surface 43 opposite to the upper cavity surface 42.
And the first and second ejector plates 221 and 222 that are vertically movable and held by the first and second ejector plates.
A stopper member 223 that limits the movable range of the members 221 and 222, and one end of which is connected to the first ejector plate 221, and the other end of which pushes out the molded product 4A in the downward direction, the first and second ejector pins 224 and 225, and the third ejector. From the pin 226 and the biasing member 277 that biases the first and second ejector plates 221 and 222 downward when the upper mold 2 reaches the preset position when the upper mold 2 moves upward due to the mold opening. Become.

The stopper member 223 is of a hanging type, one end of which is engaged with the upper die mounting plate 24 and the other end of which is engaged with the second ejector plate 222 when the die is opened.
It controls the extrusion amount of 4, 225 and 226.

One end of the first ejector pin 224 is fixed to the first ejector plate 221, and the other end of the first ejector pin 224 can move in the vertical passage 205 of the tunnel gate portion 20 of the upper mold 2, and above the crossing position P1 when the mold is closed. In addition, the lengths are respectively located below the crossing position P1 when the ejector portion 22 is actuated by opening the mold.

One end of the second ejector pin 225 is fixed to the first ejector plate 221, and the other end of the second ejector pin 225 is movable toward and away from the upper cavity surface 42 side of the upper mold 2 so that the cavity surface 42 is activated when the ejector portion 22 is activated when the mold is opened. The length is more protruding toward the molded product 4A side. The other end of the second ejector pin 225 has a Z-shaped notch P2, and is located on the same plane as the upper cavity surface 42 when the mold is closed.

One end of the third ejector pin 226 is fixed to the first ejector plate 221, and the other end of the third ejector pin 226 is movable toward and away from the horizontal passage 202 side of the tunnel gate portion 20.
It is located on the same plane as the wall surface 202b on the side of the upper mold 2 forming 02, and has a length protruding from the wall surface 202b when the ejector portion 22 is actuated when the mold is opened.

The biasing member 227 has one end engaged and held by the first ejector plate 221, and the other end penetrating the upper mold 2 and extending in the lower mold 1 direction. The other end of the biasing member 227 has a vertical split groove 227a,
A tip engaging portion 227b is formed that is elastically deformed in the radial direction and has an outer diameter that is reduced and that can be expanded from the reduced state.

Next, a case will be described in which the insert film injection molding machine of Example 1 formed as described above is used to form a molded product 4A having the insert film 8.

According to the film insert injection molding machine of this embodiment, when the lower mold 1 and the upper mold 2 are in the mold open state (see FIG. 3), the lower mold surface 1 of the lower cavity surface 40 of the lower mold 1 is On the other hand, the insert film 8 is placed in a horizontal state with the exposed surface 80 side serving as the design display surface placed and the back surface 81 side facing upward. Then, as shown in FIG. 1, the lower mold 1 and the upper mold 2 are closed. At this time, the biasing member 22
The tip engaging portion 227b of 7 penetrates the engaging hole 10 of the lower mold 1. Thereafter, the molding material is injected and filled from the tunnel gate portion 20 of the upper mold 2 toward the back surface 81 side of the insert film 8. At this time, the insert film 8 is
The mounting surface 41 from the back surface 81 side by the injection pressure of the molding material.
Then, the molding material is securely held at a predetermined set position, and the molding material is filled in the cavity 4 without invading and wrapping around the exposed surface 80 side. Then, a molded product 4A integrated with the insert film 8 is molded. Next, when the mold is opened, the upper mold 2 moves upward with respect to the lower mold 1 and separates. At this time, when the upper mold 2 reaches the preset mold opening position while the molded product 4A is adhered and held to the upper cavity surface 42 by the holding mechanism 21, the tip of the biasing member 227 of the ejector portion 22 is reached. The engagement portion 227b engages with the engagement portion 10a of the engagement hole 10 of the lower mold 1. When the upper mold 2 is further moved upward in this state, the biasing member 227 biases the first ejector plate 221 engaged with one end thereof downward. Then, the first and second ejector pins 224, 225
And the third ejector pin 226 communicate with each other, the other end (tip) of the first ejector pin 224 moves below the intersection position P1 of the tunnel gate 20, and the second ejector pin 22
The other end (tip) of 5 projects from the upper cavity surface 42,
The other end (tip) of the third ejector pin 226 is the upper mold wall surface 202.
It protrudes from b (see Fig. 2). As a result, the first ejector pin 224 is connected to the vertical passage 2 of the tunnel gate portion 20.
The rod-shaped molding material 4a of 05 is extruded, and the second ejector pin 225 forms the back surface 8 of the insert film 8 of the molding 4A.
Abut the part integrally formed with 1 and extrude it
The ejector pin 226 pushes out the molding material (not shown) of the horizontal passage 202 of the tunnel gate portion 20 and forcibly releases the holding of the molded product 4A by the holding mechanism 21. Then, the molded product 4A extruded as shown in FIG. 2 is separated from the Z-shaped notch P2 of the second ejector pin 255 and taken out to the outside.

Therefore, according to the injection molding machine of the first embodiment,
When the molded product 4A is pushed downward by the ejector portion 22 from the state of being held by the upper mold 2, the insert film 8 inserted at the lower end side of the molded product 4A has an exposed surface 80 serving as a design display surface thereof. Is located on the side opposite to the ejector portion 22, so that the design display surface is not scratched.

Further, as in the case of using the conventional side opening injection molding machine, it is possible to eliminate the problem caused by setting the injection film 8 in the vertical direction on the setting surface of the cavity, and it is possible to greatly reduce the defect rate. .

Further, when opening the injection molding machine of the present embodiment,
The urging member 227 moves upward together with the upper die 2 because the first ejector plate 221 that engages the tip engaging portion 277b is restricted from moving downward by the stopper member 223. As shown, the tip engaging portion 227b is disengaged from the engaging portion 10a of the engaging hole 10 of the lower die 1, so that the upper die 2 and the lower die 1 can obtain a wide die opening stroke L. Therefore, the insert film 8 is placed on the mounting surface 41 of the lower cavity surface 42 of the lower mold 1.
Is easy to set, and the molded product 4A can be taken out to the outside,
Lower cavity surface 40 and upper cavity surface of both molds 1 and 2
Workability such as cleaning of 42 is improved.

In addition, the embodiment of the present invention is not limited to the first embodiment, and for example, a hot runner can be used in the system of the film insert injection molding machine of the system shown in FIG.

[Brief description of drawings]

1 to 3 relate to the film insert injection molding machine in Example 1, FIG. 1 is a sectional view showing a mold closed state, FIG. 2 is a sectional view showing a state during mold opening, and FIG. It is sectional drawing which shows the state after mold opening. Fourth
The drawing is a partially enlarged sectional view showing a partially enlarged view of FIG. 1 ... Lower mold 2 ... Upper mold 3a ... Lower mating surface, 3b ... Upper mating surface 4 ... Cavity, 20 ... Tunnel gate part 21 ... Holding mechanism, 22 ... Ejector part 40 ... Lower cavity surface 41 ... Mounting surface, 42 … Upper cavity surface

Claims (1)

[Claims] 1. A lower die having a mounting surface on which a cavity is formed on a mating surface at a horizontal position and an insert film is mounted on the cavity, and a bent gate passage is provided, and the lower mold is mounted on the mounting surface of the cavity. And a gate portion for injecting a molding material toward the back side of the insert film through the gate passage, and a molded product integrally molded with the insert film is cured in the gate passage of the gate portion when the mold is opened. A holding mechanism for holding a molding material portion connected to a part of the molded product, and an ejector pin movably advancing into the gate passage of the gate portion are arranged, and the molded product held by the holding mechanism is moved downward. A film insert injection molding machine comprising: an upper mold having an ejector portion that is pushed out to release the holding of the holding mechanism.