JP2964667B2 - Different material composite 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 composite injection molding apparatus of a different material, which is used for compounding a primary molded product with a secondary molded product such as a sealing material and performing injection molding.

[0002]

2. Description of the Related Art In recent years, a composite product obtained by combining a primary molded product with a secondary molded product such as a sealing material is injection-molded by one injection molding apparatus. Specifically, this injection molding is called high mold injection molding, in which one of the fixed or movable dies is sequentially replaced with a primary or secondary molding die, and the primary molded die is then replaced. The secondary molding is compounded into the primary molding by exchanging and performing secondary molding. Two-color molding and plastic molding with a sealing material correspond to this.

In the conventional high-mold injection molding method, the conventional high-mold injection molding has two injection units, one for the primary molding material and the other for the secondary molding material, in one injection molding machine. This was performed using a dedicated machine for high-mold molding.

Further, since the molding material on the secondary side is in a liquid state, burrs are likely to occur unless the injection volume is adjusted to a very small amount.
In the conventional secondary injection unit, the injection capacity is adjusted only by the stroke length of the injection cylinder having the maximum injection capacity, which has a considerable margin in order to correspond to various product shapes.

[0005]

In this system, a dedicated high mold molding machine having two injection units is required, so that the equipment is greatly increased and the cost of the molding machine is extremely high. I will.

In general, there is a considerable need to easily remodel a general-purpose molding machine for molding only a primary-side general-purpose plastic to perform high-mold molding. Due to the condition that an injection unit must be provided separately, the modification was too large and could not be done easily.

Further, since the secondary injection material is in a liquid state, it has good fluidity and easily generates burrs. Therefore, it is desirable to control the injection volume to a very small amount. In this case, precise control was difficult because there was no other way but to control the injection volume only by the cylinder stroke of the injection cylinder having a large inner diameter.

Accordingly, the present invention provides a composite injection molding apparatus of a dissimilar material using a reaction-curable liquid secondary molding material having a small capacity, whereby the apparatus can be simply constructed or the apparatus can be made versatile. It is an object of the present invention to reliably measure a secondary material.

[0009]

According to the present invention, there is provided a high-mold injection molding apparatus as set forth in the appended claims.

[0010] The method of attaching the injection portion to the mold may be either a method of embedding it inside the mold or a method of attaching it outside the mold.

[0011]

According to the dissimilar-material composite injection molding apparatus of the present invention, a secondary material injection apparatus corresponding to a conventional secondary injection unit is provided.
Since the material injection section and the injection section are configured separately, and at least the injection section is fixed to the secondary cover mold, a means for moving the nozzle of the injection section toward and away from the mold can be omitted,
In addition, the material pumping section can be fixedly provided on the ground or with respect to the device, and the configuration of the device can be simplified.

Further, since the material pumping section only needs to pump the liquid secondary molding material, it can be designed with versatility to various injection sections.

Further, the injection portion may be individually designed according to the material properties and the injection amount so that a small amount of the secondary molding material can be injected. High-mold molding can be performed using a general-purpose molding machine if a dedicated high-mold molding machine is not used, and at least a secondary material injection device is incorporated as part of the mold during mold production. Can be.

In addition, since a dedicated cylinder having an appropriate injection capacity according to the capacity of the secondary molding cavity can be incorporated into each mold, a very small injection capacity can be controlled and a good composite without burrs can be obtained. Molded articles can be made.

[0015]

FIG. 1 is an explanatory view showing a dissimilar material composite injection molding apparatus according to one embodiment of the present invention.

The dissimilar material composite injection molding apparatus of this embodiment is a plastic material with a sealing material obtained by compounding a primary molded product made of a thermoplastic resin with a secondary molded product as a sealing material made of a two-component silicone rubber. It is to be injection molded.

In the figure, a cover mold 2 is arranged to face a reference mold 1. The overmold 2 is a primary mold 2-
1 and a secondary mold 2-2. The reference mold 1 and the overlaid mold 2 are configured such that one mold is fixed and the other mold is movable in a direction (Y) orthogonal to the mold alignment direction (X). In the example, the reference mold 1 is fixed in both the (X) and (Y) directions, the cover mold 2 is movable in the (X) and (Y) directions, and the primary injection unit 3 is the reference mold 1. Is disposed on the back surface side of the cover mold 2 on the center axis of the cover. The primary injection molding unit 3 is capable of approaching / separating from the nozzle fitting hole 4 provided in the mold 2-1 in a state where the primary alignment mold 2-1 is fitted to the reference mold 1.

The figure shows a primary overmold 2-
1 shows the state when the primary injection unit 3 is approached to perform the primary injection, then the injection unit 3 is retracted, and the cover mold 2 is changed to the next one.

In this state, a primary molded product 5 is injection-molded in the reference mold 1. The secondary molding die 2-2 is fitted to the primary molded product 5, and a two-part liquid rubber as a secondary molding material is injected into a secondary cavity formed between the two, so that the primary molded product 5 is formed. A composite product with a rubber sealing material is obtained. The injection amount is generally about several grams to several tens of grams.

In order to inject the secondary molding material, an injection cylinder 6 is built in the secondary cover mold.

The injection cylinder 6 has an injection nozzle at the tip thereof, and this nozzle is connected to the secondary cavity via a gate.

The injection cylinder 6 is connected to a liquid receiving pipe 7, a cooling pipe 8, and driving air pipes 9, 10, and these pipes are connected via a flexible pipe to a material pumping section 11 installed on the ground. , Cooling water supply device 12, air directional switching valve 1
3 respectively. The material pumping section 11 includes A,
It comprises tanks 11a and 11b for supplying the B2 liquid, and a mixer 11c for mixing the two liquids fed from these tanks 11a and 11b. The switching valve 13 is connected to an air source 14.

In the above-described material injection apparatus, when air is injected into one chamber in the cylinder 6 through the air pipe 9, the piston in the cylinder 6 is moved rightward in FIG. Weigh the secondary molding material. At this time, the cooling water is flowing through the cooling water pipe 8,
Since the entire cylinder and the liquid receiving pipe 7 are cooled, the received secondary molding material does not harden.

Next, the reference mold 1 is overlaid with a secondary mold 2-2.
Is adjusted, the air-direction switching valve 13 is switched, and the piston in the cylinder 6 is moved leftward in the figure. Then, the secondary molding material in the cylinder 6 is injected into the secondary cavity via the nozzle and the gate. 2
The secondary molding material injected into the next cavity is cured by the heat of the mold, and is integrated with the primary molded product 5 to be composited.

Next, the secondary overmold 2-2 is retracted,
The product is knocked out, the secondary overmold 2-2 is replaced with the primary overmold 2-1 and returns to the original process, and these processes are repeated to produce a composite product one after another.

As described above, in the dissimilar material composite injection molding apparatus of this embodiment, the nozzle of the injection cylinder 6 does not need to be moved with respect to the dies 1 and 2, so that the apparatus configuration is simplified and its control is easy.

The material pumping section 11 can be composed of a mixer 11c and a pressure tank, and can be used for a mold 2 which is appropriately replaced, so that it is versatile and can be used for general injection without excessive capital investment. The molding device can be easily modified.

Further, since the injection cylinder 6 can be designed for each die or in series according to the injection amount, there is no need to change the material at the time of die replacement, and the optimum injection process can be performed according to the secondary molded product. Quality can be stabilized.

In the above embodiment, the reference mold 1 is fixed, but the cover mold 2 can be fixed as described above. In this case, the injection cylinder 6 and the material pumping unit 1
The connection such as 1 may be a fixed pipe.

FIG. 2 is an explanatory view showing an example in which the injection cylinder is mounted outside the mold.

In the present embodiment, the injection cylinder 15 is fixed to the runner 16 on the outside of the secondary overmold 2-2.

In this embodiment, since the injection cylinder 15 is provided outside the mold, a means for cooling the cylinder 15 is unnecessary.

FIG. 3 shows an example in which a mixer 18 is provided at the tip of an injection cylinder 17 in the composite injection molding apparatus of different materials shown in FIG. The cooling water pipe 19 is connected only to the mixer 18. A pair of cylinders 17 are provided for the liquids A and B,
One mixer 18 is arranged in the middle of both cylinders, and the two mixers 18 injected from both cylinders 17 by this mixer 18
Mix the liquid.

In this embodiment, since the secondary molding material mixed by the mixer 18 provided at the tip of the cylinder 17 is injected into the secondary cavity, high-mold injection molding can be performed as in FIG.

Also, since the two liquids before mixing can be preheated by the cylinder 17, the secondary molding material can be heated and injected into the secondary cavity, and the curing speed can be increased by that amount and the cycle time can be shortened. Can be hidden. However, in order to obtain this effect, the capacity of the mixer 18 needs to be sufficiently smaller than the injection amount.

In the above embodiments, the secondary molding material is shown as an example of a two-part liquid rubber, but the same applies to a liquid resin other than rubber.

[0037]

As described above, the present invention is a dissimilar material composite injection molding apparatus as described in the claims, and a secondary material injection apparatus corresponding to a conventional secondary injection unit is provided.
Since the material injection section and the injection section are configured separately, and at least the injection section is fixed to the secondary covering mold, a means for moving the nozzle of the injection section toward and away from the mold can be omitted,
Further, the material feeding section can be fixedly provided on the ground or in the apparatus, so that the apparatus configuration can be simplified and the existing molding machine can be easily modified.

Further, since the material feeding section only needs to feed the liquid secondary molding material simply by pressure, it can be designed with versatility for various injection sections.

Further, the injection portion may be individually designed in accordance with the material properties and the injection amount so that a small amount of the secondary molding material can be injected. High-mold molding can be performed using a general-purpose molding machine if a dedicated high-mold molding machine is not used, and at least a secondary material injection device is incorporated as part of the mold during mold production. Can be.

In addition, since a dedicated cylinder having an appropriate injection capacity according to the capacity of the secondary molding cavity can be incorporated in each mold, a very small injection capacity can be controlled and a good composite without burrs can be obtained. Molded articles can be made.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing a dissimilar material composite injection molding apparatus according to one embodiment of the present invention.

FIG. 2 is an explanatory view showing an example in which an injection cylinder is provided outside a mold.

FIG. 3 is an explanatory view showing an example in which a mixer is provided at the tip of an injection cylinder.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 reference mold 2 cover mold 3 primary injection unit 5 primary molded product 6 injection cylinder 11 material feeding section

Continuation of front page (56) References JP-A-62-260611 (JP, A) JP-A-2-227224 (JP, A) JP-A-2-206520 (JP, A) JP-A-4-52115 (JP) JP-A-64-69316 (JP, A) JP-A-64-18613 (JP, A) JP-A-62-152822 (JP, A) JP-A-56-161621 (JP, A) 2-124119 (JP, U) Japanese Utility Model 63-100211 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) B29C 45/00-45/24

Claims (1)

(57) [Claims] 1. A primary or secondary cover mold is sequentially associated with a reference mold, and after injection of a primary molding material, a secondary cover is formed between the primary molded product and the secondary cover mold. Inject a small volume reaction-curable liquid secondary molding material into the next cavity,
A dissimilar material composite injection molding apparatus for compounding a secondary molded product into a secondary molded product and performing injection molding, the secondary material injection device for injecting the secondary molding material includes a material pumping unit and a measuring cylinder. An injection unit configured to measure the material pumped from the pumping unit and inject the material into the secondary cavity, at least the injection unit of the secondary material injection device,
A composite injection molding apparatus of a different material, which is fixedly mounted inside or outside the secondary cover mold.