JPH09254181A - Method and apparatus for molding laminated molded object - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance moldability and to suppress the material loss caused by the leakage of a material to the outside by well venting air at a time of molding in a method and apparatus for molding a laminated molded object by reactive injection molding. SOLUTION: When a hard urethane resin soln. is injected and filled into the cavity formed by a cavity mold 20 and a core mold 30 to mold a hard urethane core material, an air venting mechanism 50 capable of adjusting air venting quantity is set to the core mold 30 so as to perform control so that a large quantity of air in the cavity is discharged to the outside at the initial period of injection and the discharge quantity is reduced with the elapse of time and, on the point of the completion of filling, only a slight quantity of air is discharged. By effectively controlling air venting quantity as mentioned above, moldability in reactive injection molding is enhanced and material loss is suppressed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molding method and a molding apparatus for a laminated molded article represented by an automobile door trim and the like, and more particularly to a method for molding a laminated molded article with improved moldability in a reaction injection molding method and a molding method. The present invention relates to a molding device.

[0002]

2. Description of the Related Art For example, various interior parts are mounted in a vehicle interior. The interior parts require a fiber board, a resin board, etc. having shape retention and rigidity for mounting to a vehicle body panel. 2. Description of the Related Art A laminated molded body in which a skin material having a cushioning property and a decorative property is laminated on a surface side of a core material molded into a shape is generally known.

[0003] By the way, the disadvantages of the core material made of fiberboard, resin board, etc., are that they tend to be heavy and unsuitable for reducing the weight of products, and that they are not satisfactory in formability. There is a problem in that it cannot effectively cope with a product having a complicated curved surface shape.

As measures against this, it has been proposed and implemented to use a hard urethane reinforced with glass fiber or the like as a core material to promote weight reduction and improve moldability.

FIG. 13 is a sectional view showing the construction of an automobile door trim using a hard urethane core material. This automobile door trim 1 is made of a hard urethane resin liquid mixed with glass fibers and molded into a required shape. Urethane core material 2
And a skin material 3 which is integrally attached to the surface side so as to obtain decorativeness and a good surface feel.

Further, as a conventional example of the method of manufacturing the automobile door trim 1, as shown in FIG. 14, when the cavity mold 4 located on the lower side and the core mold 5 located on the upper side are in the mold open state. , The skin material 3 is set between the molds 4 and 5, and then the core mold 5 is clamped to the cavity mold 4, and the injection head of the injection machine 6 is placed in the cavity formed between the molds 4 and 5. By injecting and filling a hard urethane resin liquid mixed with glass fiber through 6a, the hard urethane core material 2 is formed into a required shape by reaction injection molding, and the skin material 3 is integrated on the surface side thereof.

Further, in the above-mentioned reaction injection molding method of the hard urethane resin liquid, since the air staying in the cavity dissipates the fluidity of the urethane, as shown in FIG. An air vent groove 7 is provided.

The air vent groove 7 usually has a width of 2-5.
mm and a depth of about 1 to 3 mm are set.

[0009]

As described above, in the conventional reaction injection molding method, in order to secure the fluidity of the urethane resin liquid, a predetermined portion of the core mold 5 (relatively separated from the injection port, the resin liquid is The air bleeding groove 7 is provided in the vicinity of the last reaching position), but it is very difficult to optimally adjust the dimensions and the like of the air bleeding groove 7 depending on the product shape and the characteristics of the resin material used.

That is, when the width of the air bleeding groove 7 is made smaller than necessary, air bleeding cannot be performed reliably, the flowability of the urethane resin liquid deteriorates, and voids are generated on the product surface. However, there is a drawback that the urethane resin liquid is not spread to the outer peripheral end, and the density of the peripheral end portion is reduced, resulting in poor rigidity.

On the other hand, when the width of the air bleed groove 7 is set larger than necessary, air bleeding is surely performed, but the urethane resin liquid leaks from this air bleed groove, resulting in material loss. There was a problem.

As described above, it is difficult to optimally adjust the groove width and the like of the air bleeding groove 7 depending on the shape of the product and the characteristics of the resin liquid used, and there has been an urgent need to solve this problem.

The present invention has been made in view of the above circumstances, and a reaction injection molding method and a molding apparatus for a laminated molding formed by integrally molding a hard urethane core material and a skin material by reaction injection molding. It is an object of the present invention to provide a molding method and a molding apparatus for a laminated molded body, which can remarkably improve the moldability by performing air bleeding optimally during molding and have extremely little material loss.

[0014]

In order to achieve the above-mentioned object, the present invention sets the surface side of the skin material on the mold surface of the cavity mold so that the surface of the skin material faces downward, and the space between the cavity mold and the core mold is set. The cavity is filled with hard urethane resin liquid through the injection head of the injection machine, and the hard urethane core material is molded into the required shape by reaction injection molding, and the surface layer of the hard urethane core material is laminated with the skin material. In the method of molding a molded body, the core mold is provided with an air bleeding mechanism,
During the cycle from the initial injection of the hard urethane resin liquid to the end of filling, the amount of air bleeding by the air bleeding mechanism is set large at the beginning of injection, and the amount of air bleeding by the air bleeding mechanism is set small at the end of filling. Characterize.

Further, the present invention is composed of a cavity mold and a core mold which can be clamped with each other, and is formed by reaction injection molding into a hard urethane core material and a skin material on the surface side of the hard urethane core material. In a molding apparatus for a laminated molded body, in which the above and the above are integrated, the core mold is provided with a divided block which moves up and down by a cylinder, and a parting face between the divided block and a parting face of the cavity mold is provided. The feature is that the variable clearance is used as the air bleeding portion.

Here, the material used for the hard urethane core material is a polyol type two-liquid mixed type, in which the liquid A has a composition of polyol and a foaming agent (water), and the liquid B has an isocyanate composition before injection. Mix.

Further, in order to secure the rigidity of the hard urethane core material, a reinforcing material (for example, wallasite, talc, calcium charcoal, glass fiber, etc.) may be mixed in the liquid A, and
When the glass fiber mat is set in the mold and the hard urethane resin liquid is injected and molded, the glass fiber mat may be provided as an inner layer in the core material.

The density of the hard urethane core material is 0.3.
It is about 0.6 g / cm ³ , preferably about 0.4 g / cm ³ .

As the skin material, a laminated sheet in which polyethylene foam is lined on the back surface of a PVC sheet or a PVC foam sheet can be used, and the sheet-shaped skin material is integrally formed during reaction injection molding of a hard urethane core material. It may be molded, or may be preformed by vacuum molding before reaction injection molding.

Further, as an air bleeding mechanism, a divided block is incorporated in a core mold so as to be movable up and down, and the clearance between the parting surface of this divided block and the parting surface of the cavity mold is adjusted to remove the air. However, if desired, an air vent groove may be formed in the parting surface of the divided block. Further, the divided block is operated by an elevating cylinder such as an air cylinder or a hydraulic cylinder.

The timing of the vertical movement of the divided blocks may be such that each divided block is operated with the passage of time after the injection machine starts the injection, and a sensor is provided at a predetermined position of the core type. Alternatively, the sensor may detect the arrival of the resin liquid, and the signal may be used to operate the cylinder to operate the divided block.

As is apparent from the above construction, according to the present invention, as the air bleeding mechanism at the time of reaction injection molding,
By setting a vertically movable split block in the core type, the initial injection of urethane resin liquid from the injection machine,
Since the divided block is located in the upper position and a large clearance is secured between the parting surface of the cavity type and the parting surface of the divided block, a large amount of stagnation in the cavity occurs during the initial injection of the urethane resin liquid. Air can be quickly discharged out of the mold, and as the filling progresses, the division block is gradually lowered to gradually narrow the clearance between the cavity mold parting surface and the division block parting surface. Just before the filling is completed, if the mold surface of the cavity mold and the mold surface of the divided block are brought into contact with each other or face each other with a minute clearance, the urethane resin liquid will almost leak out of the mold. Without, the material loss can be reduced.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a method and apparatus for forming a laminated molded product according to the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 is a front view showing an automobile door trim molded by the method of the present invention, FIG. 2 is a sectional view showing the constitution of the automobile door trim, and FIG. 3 is a schematic constitution of a molding apparatus used in the method of the present invention. FIG. 4 is a vertical sectional view, FIG. 4 is a plan view of a core mold in the molding apparatus, FIGS. 5 to 9 are sectional views showing respective steps of the method of the present invention, and FIG. 10 is a schematic view showing another embodiment of the method of the present invention. 11 and 12 are cross-sectional views showing modified embodiments of the air bleeding mechanism used in the method of the present invention.

1 and 2, an automobile door trim 10 is made of a hard urethane core material 11 which is almost uniformly filled with glass fibers, and a surface of which is integrated with a hard urethane core material 11, which has a cushioning property and a surface feeling. The material 12 is generally configured.

More specifically, as the material of the hard urethane core material 11, a two-liquid mixing type in which A liquid: polyol component and B liquid: isocyanate component are mixed is used. In addition, the milled glass fiber (fiber length of 0.1 to 1.0 mm, preferably 0.2 to 10 parts by weight based on 100 parts by weight of polyol).
0.3 mm, fiber diameter 5 to 50 μ), water (foaming agent) is mixed, and injection molding is performed to obtain a hard urethane core material 11
Is molded into the curved surface shape shown in the figure, and the plate thickness of the hard urethane core material 11 is approximately 4 mm throughout, and good rigidity is maintained throughout due to the reinforcing effect of the milled glass fiber.

In place of the milled glass fiber, an inorganic filler such as warasite, talc, calcium carbonate may be used.

On the other hand, the skin material 12 is PV in this embodiment.
A laminated sheet in which polyethylene foam (2 to 3 mm, foamed 30 to 40 times) is laminated on the back of the C sheet (sheet thickness 0.5 mm) is used, but a foam PVC sheet or a PVC slush molded powder slush Material 12 may be used.

It should be noted that the skin material 12 may be a sheet-shaped material integrally molded at the time of injection molding of the hard urethane core material 11.
Further, it may be preformed by vacuum forming or the like in advance.

By the way, a feature of the present invention resides in that when the above-mentioned automobile door trim 10 is subjected to the reaction injection molding, a material loss is small and an extremely excellent moldability is secured.

That is, the above-described automobile door trim 1
Before describing the molding method of No. 0, a schematic configuration of a molding apparatus used for the molding method will be described with reference to FIGS. 3 and 4.

First, the molding apparatus includes a cavity mold 20 having a desired mold surface shape, a core mold 30 having substantially the same mold surface shape, and an injection machine installed in the core mold 30 for injecting a hard urethane resin liquid. And 40.

The core die 30 located above the cavity die 20 located below can be moved up and down by a predetermined stroke by an elevator device (not shown). When the core die 30 reaches the bottom dead center, The cavity C having a predetermined space is formed between the core die 30 and the cavity die 20.

Further, the injecting machine 40 is provided with an injecting head 41 for injecting and filling a hard urethane resin liquid into the cavity at the tip end portion thereof, and a plurality of air bleeding mechanisms 50 are provided at predetermined positions of the core mold 30. It is installed in the place.

The characteristic of the molding apparatus used in the present invention is that the hard urethane core 11 is
In the reaction injection molding, the amount of air discharged to the outside can be controlled with the lapse of time from the start of the injection of the hard urethane resin liquid to the end of the injection.

That is, in this embodiment, the air bleeding mechanism 50 is formed on the lifting cylinder 51, the divided block 52 that moves up and down by the lifting cylinder 51, and the bottom surface (parting surface) of the divided block 52. The lifting cylinder 51 may be a conventional cylinder such as a hydraulic cylinder or an air cylinder, but the operating timing is as follows.
Starting from the beginning of the injection of the urethane resin liquid from the injection head 41 of 0, the descending operation is started several seconds later, and the operation is performed so that the divided block 52 comes into contact with the mold surface of the cavity mold 20 just before the completion of the filling. Controlled.

For example, as shown in FIG. 4, in this embodiment, the air bleeding mechanism 5 is provided at four locations around the core die 30.
0 is installed respectively, but the air bleeding mechanism 50 is set at a place where the urethane resin liquid is expected to arrive relatively early.
a and 50b, the operation of the divided block 52 is the same as that of the divided block 52 after 2 to 3 seconds after the injection of the urethane resin liquid.
The air bleeding mechanism 50 is controlled to start the descending operation of the
In c and 50d, after injection of the urethane resin liquid, 5 to 6
The operation timing of each air bleeding mechanism 50 is controlled in consideration of the product shape such that the descending operation is started after a second.

Next, the molding process of the automobile door trim 10 using the above-mentioned molding apparatus will be described step by step.

First, as shown in FIG. 5, when the core mold 30 is in the uppermost position, that is, in the mold open state, the skin material 12 is set in the mold. In the air bleeding mechanism 50, the divided block 52 is located above.

Then, the core die 30 starts descending, and as shown in FIG. 6, the core die 30 reaches the bottom dead center and the core die 30 is reached.
And the cavity mold 20 are engaged with each other through a predetermined clearance, and then the hard urethane resin liquid is injected into the cavity C formed between the molds 20 and 30 through the injection head 41 of the injection machine 40 provided in the core mold 30. P is injection filled.

At this time, in each air bleeding mechanism 50 provided at a predetermined position of the core die 30, the cylinder 51 operates,
As shown in FIG. 7, each of the divided blocks 52 starts descending in the direction of the arrow, but at the initial stage of injecting the hard urethane resin liquid P, the divided blocks 52 are at a considerably upper position, so that the cavity between the molds 20 and 30 is increased. The air staying in C is quickly removed to the outside through a wide area air passage indicated by reference symbol A in the figure, whereby the hard urethane resin liquid satisfactorily flows in the mold and quickly enters the cavity C. It will go through without any trouble.

Then, as the hard urethane resin liquid P is filled in the cavity C, the divided block 52 in the air bleeding mechanism 50 continues the descending operation, and immediately before the filling of the hard urethane resin liquid is completed, as shown in FIG. As shown in FIG. 9, the bottom surface of the divided block 52 contacts the mold surface of the cavity mold 20.

Here, since the hard urethane resin liquid P leaking from the cavity C to the outside only leaks to the outside through the air bleeding groove 53 having an extremely narrow groove width, the leak amount is very small and the conventional one. There is almost no material loss compared to.

When the injection machine 40 is separated from the core mold 30 and the mold is open, the cavity 40 is filled with the hard urethane resin liquid P from the injection machine 40, and then the core mold 3 is used.
0 may be clamped to the cavity mold 20.

As described above, according to the method of the present invention, as the air bleeding mechanism 50, the air bleeding groove 53 is formed in the divided block 52.
The cylinder 51 is used to move the divided block 52 to remove a large amount of air out of the mold in the initial stage of injection, and when the filling is almost completed, the air is discharged to the outside through the air bleed groove 53 having an extremely small groove width. Since it is to appropriately control the discharge amount of the hard urethane resin liquid P, good fluidity of the hard urethane resin liquid P can be ensured, and defects such as conventionally occurring molding defects such as voids and a decrease in rigidity due to insufficient density at the end of the product are caused. Can be effectively solved, and it is possible to mass-produce accurate molded products.

Further, by providing the air bleeding groove 53 having a small groove width in the divided block 52, the leakage of the hard urethane resin liquid to the outside can be suppressed to the minimum, the material loss is extremely small, and the material is effectively used. There is also an advantage that the cost can be reduced.

In addition, the hard urethane core material 11 is the skin material 1.
There is also an advantage that more accurate molding can be performed by freely adjusting the operation timing of the air bleeding mechanism 50 in consideration of the thickness specifications of No. 2 and molding conditions such as the outside air temperature and the mold temperature.

As a method of controlling the operation timing of the air bleeding mechanism 50, the elevating cylinder 51 of the air bleeding mechanism 50 is temporally set with reference to the time of injecting the hard urethane resin liquid P from the injecting head 41 of the injecting machine 40. In addition to the method of controlling the operation timing, a sensor is installed in the cavity mold 20 or the core mold 30, and the filling situation of the hard urethane resin liquid P is detected by the sensor, and the cylinder 51 of the air bleeding mechanism 50 is detected.
You may employ the method of operating.

Further, as shown in FIG. 10, as a method of reinforcing the hard urethane core material 11, after a reinforcing mat such as a glass fiber mat G is set on the upper side of the skin material 12a set in the cavity mold 20, the hard urethane resin is set. It is also possible to inject the liquid P and then perform mold clamping.

Also in this method, the air bleeding mechanism 50
In the same manner as in the above-described embodiment, the air bleeding at the time of filling the hard urethane resin liquid P can be smoothly controlled.

The hard urethane resin liquid P may be poured into the cavity after the cavity mold 20 and the core mold 30 are clamped.

Next, FIGS. 11 and 12 show the air bleeding mechanism 50.
11 shows a configuration in which the divided block 52 having a narrow width is installed only in the installation location of the air bleed groove 53, and the shape and dimensions of the air bleed groove 53 are different from those of the first embodiment. However, the operation timing and function of the divided block 52 are the same as in the first embodiment.

In this embodiment, when the rigid urethane core material is subjected to reaction injection molding, the fluidity is usually changed due to the outside air temperature, the mold temperature, etc., and the flow of the rigid urethane resin liquid P becomes fast. It becomes a burr of and leaks to the outside,
In this embodiment, since the width of the divided block 52 is narrow, the vertical stroke of the divided block 52 is set to be larger than that in the above-described embodiments, and thus the air bleeding amount can be more accurately and There is an advantage that the amount can be reduced.

Further, the one shown in FIG. 12 has a configuration in which the air vent groove 53 is omitted by more accurately controlling the clearance between the parting surface of the divided block 52 and the parting surface of the cavity mold 20. Also in this embodiment, in this embodiment, the divided block 52 is located at the uppermost position in the initial stage of the injection of the hard urethane resin liquid P, and when the filling of the hard urethane resin liquid P is almost completed, Since the parting surface and the parting surface of the cavity mold 20 face each other with a minute clearance, there is an advantage that the amount of burr can be suppressed.

[0055]

As described above, according to the present invention, the following special effects can be obtained.

(1) The present invention is a method for molding a laminated molded article by reaction injection molding, wherein during reaction injection molding by an air bleeding mechanism, a large amount of air staying in the cavity is removed from the mold at the initial stage of injection. The amount of air discharged over time is reduced, and a slight amount of air in the cavity is removed to the outside of the mold just before the end of filling, thereby smoothly controlling the air bleeding in the cavity. As a result, the fluidity of the resin liquid in the cavity can be increased, molding defects such as voids and short shots that have conventionally occurred can be effectively eliminated, and accurate laminated moldings can be mass-produced.

(2) According to the present invention, the air bleeding amount is adjusted so that a large amount of air in the cavity can be removed to the outside at the beginning of injection and only a small amount of air is removed to the outside at the end of filling. Since it is a method, there is no problem that the resin material leaks to the outside in order to ensure good air bleeding as in the conventional method, the material loss is small, and the material can be effectively used. Have.

(3) Since the present invention controls the amount of air extracted by the air bleeding mechanism in the method for molding a laminated molded body using reaction injection molding, the thickness specifications of the core material and the skin material are Alternatively, by freely controlling the operation timing of the air bleeding mechanism according to the molding conditions and the like, it is possible to obtain good molding accuracy according to various specifications.

[Brief description of drawings]

FIG. 1 is a front view showing an automobile door trim formed by the method of the present invention.

FIG. 2 is a sectional view taken along line II-II in FIG.

FIG. 3 is a sectional view showing a schematic configuration of a molding apparatus used in the method of the present invention.

FIG. 4 is a plan view of the core mold shown in FIG.

5 is a cross-sectional view taken along line VV in FIG. 4 showing a step of setting a skin material in the method for molding a laminated molded body according to the method of the present invention.

FIG. 6 is a cross-sectional view showing an initial state of injection of a urethane resin liquid in the method for molding a laminated molded body according to the present invention.

FIG. 7 is a view showing the structure of an air bleeding mechanism in the initial state of injecting a urethane resin liquid in the method of the present invention, VII-VII in FIG.
Sectional view.

FIG. 8 is a cross-sectional view showing a state just before the completion of the filling of the urethane resin liquid in the method for molding a laminated molded body according to the present invention.

FIG. 9 is an explanatory view showing an air bleeding mechanism just before the completion of the filling of the urethane resin liquid in the method of the present invention.

FIG. 10 is a schematic view showing another embodiment of the method of the present invention.

FIG. 11 is a sectional view showing another embodiment of the air bleeding mechanism in the molding apparatus used in the method of the present invention.

FIG. 12 is a sectional view showing another embodiment of the air bleeding mechanism in the molding apparatus used in the method of the present invention.

FIG. 13 is a cross-sectional view showing a conventional automobile door trim.

FIG. 14 is a cross-sectional view showing a schematic configuration of a molding device used for molding a conventional automobile door trim.

FIG. 15 is a sectional view showing an air bleeding mechanism in a conventional molding apparatus.

[Explanation of symbols]

 10 Automotive Door Trim 11 Hard Urethane Core Material 12 Skin Material 20 Cavity Type 30 Core Type 40 Injector 41 Injecting Head 50 Air Venting Mechanism 51 Cylinder 52 Dividing Block 53 Air Venting C C Cavity P Hard Urethane Resin Liquid G Glass Fiber Mat

Claims (5)

[Claims] 1. A cavity (C) between the cavity mold (20) and the core mold (30) is set on the mold surface of the cavity mold (20) with the surface side of the skin material (12) facing down. ) Is filled with the hard urethane resin liquid (P) through the injection head (41) of the injection machine (40), and the hard urethane core material (11) is molded into a required shape by reaction injection molding. In the method for molding a laminated molded body in which the surface material (12) is integrated on the surface side of (11), an air bleeding mechanism (50) is provided in the core mold (30), and the hard urethane resin liquid (P) is initially injected. During the cycle from the filling to the end of filling, the air bleeding amount by the air bleeding mechanism (50) is set to be large at the beginning of injection, and the air bleeding mechanism (5
A method for molding a laminated molded article, characterized in that the air bleeding amount according to 0) is set small. 2. The hard urethane resin liquid (P) contains:
The method for molding a laminated molded body according to claim 1, wherein a reinforcing material is mixed. 3. A hard urethane resin liquid (P) is placed in the cavity (C) after a reinforcing mat (G) is set on the upper surface of the skin material (12) set in the cavity mold (20).
The method for molding a laminated molded body according to claim 1, wherein the hard urethane core material (11) having the reinforcing mat (G) as an inner layer is molded by pouring the hard urethane core material inside. 4. A cavity mold (2) capable of mutually clamping.
0) and a core mold (30), and a hard urethane core material (11) molded into a required shape by reaction injection molding, and a skin material (12) integrally on the surface side of the hard urethane core material (11). In the molding device for the laminated molded body, the core mold (30) is provided with a divided block (52) which moves up and down by a cylinder (51), and a parting surface and a cavity of the divided block (52). A molding apparatus for a laminated molded body, wherein a variable clearance between the mold (20) and a parting surface is used as an air bleeding portion. 5. The divided block (52) of the air bleeding mechanism (50) is adapted to individually adjust the operation timing according to the installation location on the core mold (30). Forming device for laminated molded body.