JPH0227128B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing an instrument panel, and more specifically, a method for manufacturing an instrument panel in which a base material, pad material, etc. are integrally molded into a multilayer structure of two or more layers. Regarding.

Conventionally, instrument panels are manufactured by first manufacturing the base material of the instrument panel using a metal frame or various plastics by press molding or injection molding, and then separately applying a semi-rigid material to a vacuum-formed skin made of vinyl chloride resin or ABS resin. The manufacturing process involved injecting a polyurethane foam stock solution, foaming it to create a pad material, and finally combining and integrating the base material and pad material.

However, with this method, it is necessary to manufacture the base material and pad material using separate manufacturing equipment, labor, and location, or in separate factories, and furthermore, these intermediate products must be stored and transported to the place where they will be made into final products. However, it takes many production processes and time to combine and integrate these into a final product.
It had the disadvantage of causing a large economic loss.

Therefore, a method of manufacturing an instrument panel in which the base material and the pad material are integrated through a simple process is desired, and various proposals have been made to simplify the process, but few are satisfactory.

The present invention was made in view of the above circumstances, and it is possible to integrally mold the base material and the pad material etc. in the same mold in a short time, and to achieve process simplification, reducing equipment costs, labor, space, etc. An object of the present invention is to provide a manufacturing method of an instrument panel which can save a large amount of money and has a large cost advantage.

That is, in order to achieve the above-mentioned object, the present invention, when manufacturing an instrument panel with a multilayer structure made of polyurethane molded bodies having different properties using a mold, provides a space between the polyurethane and the polyurethane at a predetermined location within the cavity of the mold. After placing a moldable core and injecting a specified polyurethane molding raw material into this cavity and curing it to obtain a polyurethane molded body, the core is removed, and then a polyurethane molding raw material different from the polyurethane molding raw material is poured into the cavity. is injected into the space corresponding to the core placement location and cured to integrate a polyurethane molded product with different properties into the polyurethane molded product.

Hereinafter, an example of manufacturing an instrument panel with a two-layer structure consisting of a polyurethane base material and a pad material by the RIM (Reaction Injection Molding) process will be described with reference to the drawings.

The RIM process involves mixing and injecting two or more chemically active liquid components with relatively low viscosity that react with each other into a closed mold using a high-pressure foaming machine to cause a rapid chemical reaction. The liquid components are basically the same as those used for normal polyurethane, but they are highly activated.

The drawings are for sequentially explaining each step of a method of implementing the present invention, and in FIG. 1, 1 indicates a female mold (lower mold) 2.
This is a mold for forming an instrument panel consisting of a male die (upper die) 3 and a male die (upper die) 3. The female mold 2 can be engaged with a fixed female mold 2a fixed on a base 4, and can be moved forward and backward from the fixed female mold 2a by a hydraulic cylinder or the like on the base 4. It is composed of two split molds including a movable female mold 2b which is arranged to be movable. The fixed female die 2a and the movable female die 2b are respectively formed with a recess 5a and an uneven portion 5b having a predetermined shape.
In addition, the male die 3 has the concave portion 5a and the uneven portion 5b in a state where the fixed female die 2a and the movable female die 2b are engaged and connected as shown in FIGS. 2 and 4.
It has a convex portion 6 corresponding to the concave portion 5 of the female mold 2 formed by the mold 2, and is detachably attached to the female mold 2. When the male mold 3 is attached to the female mold 2, a cavity 7 is formed between the concave portion 5 and the convex portion 6, and each raw material injection port 8a, 8b formed in the fixed female mold 2a is inserted into the cavity 7. Channels 9a, 9
A predetermined molding raw material is injected into the cavity 7 through b. Although not shown, the injection ports 8a and 8b each have a
A RIM injection machine is connected. These RIM injection machines house the raw material systems necessary to construct the instrument panel base material, and the other injection machine houses the raw material system that satisfies the physical properties necessary to construct the instrument panel pad material. It is accommodated.

Next, to explain the method of molding an instrument panel using the mold 1, the first step is to pull up the male mold 3 from the female mold 2 as shown in FIG. Type 2a
In the state in which the movable female die 2b is pulled out and retreated from the movable female die 2b, a core 10 of a predetermined shape is placed on the surface of the uneven portion 5b of the movable female die 2b, and then, as a second step, the movable female die 2b is moved to the fixed female die as shown in FIG. 2a, engages and connects it, attaches the male mold 3 to the female mold 2, and closes the lid. As a result, the convex portion 6 of the male die 3, the concave portion 5a of the fixed female die 2a, and the uneven portion 5 of the movable female die 2b.
A cavity 7 is formed between the movable female die 2b and the movable female die 2b, but since the core 10 is placed on the uneven portion 5b of the movable female mold 2b, the core 10 protrudes from the cavity 7 in the state shown in FIG. is in a state of In this state, one of the RIM injection machines is operated to inject a predetermined polyurethane molding raw material (for example, a base material molding raw material) into the cavity 7 from one of the injection ports 8a through the channel 9a, and harden it. As a result, a molded body 11a having a shape corresponding to the cavity 7 except for the portion where the core 10 is arranged is obtained.

After curing, the movable female mold 2b is separated from the fixed female mold 2a as shown in FIG. 3, and the core 10 is removed (third stage). Next, in the fourth step, as shown in FIG. 4, the movable female die 2b is again engaged with the fixed female die 2a. In this state, a space is formed in a portion of the cavity 7 corresponding to the location where the core 10 is disposed, and the molded body 11a exists in other portions of the cavity 7. Then, in this state, operate the other RIM injection machine,
A polyurethane molding raw material (for example, a pad molding raw material) different from the raw material is injected into the cavity 7 through the flow path 9b from the other injection port 8b into a space corresponding to the location where the core 10 is disposed, and hardened. This results in
A molded body 11b having a shape corresponding to the core 10 is molded integrally with the molded body 11a,
The overall shape corresponds to Cavity 7,
An instrument panel molded product 11 is obtained in which molded products 11a and 11b (base material and pad material) having mutually different properties are integrally molded into a two-layer structure. The molded product 11 is removed from the mold 1 after the male mold 3 is pulled up from the female mold 2 as shown in FIG. 5 (fifth stage).

After the molded product 11 is demolded, it returns to the first stage state shown in FIG. 1, and the molding is repeated in the same manner to continuously manufacture instrument panels.

In this case, it is necessary to use a material for the core 10 that has mold releasability with respect to the polyurethane molded body 11a obtained in the second step. child 10
There arises a problem that the molded body 11a adheres to itself due to the self-adhesion of the molded body 11a. In addition, in a method in which a mold release agent is applied to the core 10 instead of making the material of the core 10 from a material that has mold releasability, this mold release agent is applied to the molded body 11a obtained in the second step. This is not preferable because it may adhere to the other molded body 11b and prevent the other molded body 11b from being integrated with the one molded body 11a when the other molded body 11b is molded. Examples of materials with mold releasability include silicone resin, and as the base of the core 10, a material that itself adheres to the molded body 11a obtained in the second step is used, and the surface of this base It is possible to use a structure in which the molded body 11a is coated with or laminated with a film such as polyethylene having mold releasability to impart mold releasability to the molded body 11a.

Furthermore, as the raw materials used for molding, that is, the raw materials constituting the base material and pad material, a raw material system is used that is compatible with the RIM process and satisfies the physical properties necessary for constituting the base material and pad material. In this case, any raw material system can be used as the raw material for forming the base material as long as it satisfies the physical properties necessary to construct the base material, but usually the density when formed into a molded product is approximately 0.9~ A two-component system consisting of a polyol component system and an isocyanate component system that gives a so-called high-density microcellular elastomer of 1.2 g/cm ³ is used, or a system in which a reinforcing material such as glass fiber is mixed (so-called RRIM) is used.
〈Reinforced Reaction Injection Molding〉）
is preferably used. In addition, any raw material system can be used as the raw material for forming the pad material as long as it satisfies the physical properties necessary to construct the pad material, but usually the density when formed into a molded product is approximately
A raw material system consisting of two components, a polyol component system and an isocyanate component system, which provides a so-called low-density microcellular elastomer of 0.2 to 0.7 g/cm ³ is used.

According to the above-mentioned process, the base material and the pad material can be integrally molded easily and efficiently using one manufacturing equipment, and the molding can be performed continuously, and the RIM process is adopted. In addition, one cycle is quick and the cost advantage is very large. Furthermore, in this case, the female mold 2 is composed of a fixed female mold 2a and a movable female mold 2b, and the core 10 is placed on the movable female mold 2b and moved in and out. Removal is easy and quick, and when taking out the core in the third step, it is only necessary to open the opening to the minimum necessary, and there is no need to perform operations such as lifting the male mold 3 from the female mold 2, and the lid can be opened completely. Since there is no need to open the molded product in the second step, problems such as shrinkage due to excessive cooling of the molded product 11a obtained in the second step are unlikely to occur, and therefore, a good product can be reliably obtained and workability is also good. It is. Moreover, since the core 10 is made of a material that has good mold releasability with respect to polyurethane, it is easy to release the molded product 11 obtained in the second step.
In addition to being able to be peeled off from a, unlike when using a mold release material, the integration of both molded bodies 11a and 11b is not hindered, the adhesiveness is good, and the installation has a two-layer structure of an excellent quality base material and pad material. A mento panel molded product 11 is obtained.

In the above process, the surface of the molded body 11a molded in the second stage that comes into contact with the molded body 11b to be molded in the fourth stage can be roughened in advance with a mold, so that both molded bodies 11
The adhesive force between a and 11b can be strengthened. Further, the adhesive surfaces of both molded bodies 11a and 11b can be formed into a shape such as a concave and convex shape that engages with each other. Formation of such a roughened or uneven shape can be easily achieved by roughening the core 10 or forming the core 10 into a roughened shape. Alternatively, when removing the core 10 in the third step, the molded body 11a may be roughened or unevenness may be formed. Furthermore, by applying adhesive to the molded body 11a in this third step, both molded bodies 11a,
11b can also be firmly bonded via an adhesive.

Furthermore, in order to decorate the surface of the instrument panel, a grain pattern is formed on the concave portion 5 of the female mold 2 and/or the convex portion 6 of the male mold 3, and the pattern is formed on the surface of the panel pad material and/or the base material. Furthermore, the surface can be formed into an integral skin shape to provide strength and beauty.

Furthermore, in the present invention, depending on the shape of the core, the shape of the cavity, etc., the pad material may be molded after the base material is molded, or conversely, the pad material may be molded after the pad material is molded. good. In addition, although the above process describes a method for manufacturing an instrument panel with a two-layer structure consisting of a base material and a pad material by using the core 10, a multi-layer structure with three or more layers can be manufactured by a similar process using a core. It may also be formed into

EXAMPLES Next, the present invention will be explained in more detail with reference to Examples.

Example: Prepare a mold for molding an instrument panel as shown in the drawing above, and heat it to approximately 50 to 60°C.
The concave portion 5a of the fixed female mold 2a and the movable female mold 2 are heated to
A mold release agent was applied to the uneven portions 5b of b and the convex portions 6 of the male mold 3, respectively. As shown in FIG. 1, pull out the movable female mold 2b from the fixed female mold 2a, and
After placing the core 10 made of silicone rubber on the mold b, the movable female mold 2b was engaged and connected with the fixed female mold 2a, and the male mold 3 was clamped to the female mold 2. Next, one RIM injection machine is used to inject the raw material system (product name: "RIM-140") that makes up the base material (Mitsui Nisso Urethane Co., Ltd.).
A predetermined amount of the solution (manufactured by M. Co., Ltd.) was injected into the cavity 7 from one injection port 8a through one channel 9a and cured (hardened in about 60 seconds).

After the base material 11a was cured, the movable female mold 2b was pulled out and the core 10 was removed. Next, the movable female mold 2
Set b again on the fixed female mold 2a, and insert the other RIM
A predetermined amount of the raw material system (trade name: "Bayflex 20/30" (manufactured by Sumitomo Bayer Urethane Co., Ltd.)) constituting the pad material is poured from the injection machine through the other injection port 8b and the other channel 9b to form the core 10. It was injected into the space it occupied and allowed to harden (hardens in about 120 seconds).

After curing, the movable female mold 2b was pulled out, the male mold 3 was removed, and the instrument panel 11 in which the pad material 11b and the base material 11a were integrated was taken out.

Thereafter, the above cycle was repeated to continuously manufacture instrument panels.

The instrument panel obtained in this example has a density of approximately 1.06 g/cm ³ in the base material portion and approximately 0.30 g/cm ³ in the pad material portion, and the base material and pad material are strong. was glued to.

As explained above, according to the present invention, an instrument panel with a multilayer structure made of polyurethane molded bodies with different properties such as the base material and pad material can be manufactured in a short time and at low cost using the same molding equipment. , its industrial applicability is extremely high. The method of the present invention can be applied not only to instrument panels but also to the production of integrally molded products consisting of two or more layers having different physical properties such as hardness.

[Brief explanation of drawings]

FIGS. 1 to 5 explain the steps of a method for carrying out the present invention step by step, and are side views with a part of the apparatus used in this method in cross section. 1...Mold, 2...Female mold, 2a...Fixed female mold, 2
b...Movable female mold, 3...Male mold, 7...Cavity, 8
a, 8b... Raw material injection port, 9a, 9b... Channel, 10
...core, 11...instrument panel molded product,
11a, 11b...Polyurethane molded bodies having mutually different properties.

Claims (1)

[Scope of Claims] 1. In a method for manufacturing an instrument panel with a multilayer structure made of polyurethane molded bodies having different properties using a mold, a medium having mold releasability against polyurethane is provided at a predetermined location in the cavity of the mold. A predetermined polyurethane molding raw material is injected into this cavity and cured to obtain a polyurethane molded body, after which the core is removed, and then a polyurethane molding raw material different from the polyurethane molding raw material is poured into the core arrangement. A method for manufacturing an instrument panel, comprising: injecting the polyurethane into a space corresponding to a location and curing it to integrate a polyurethane molded product with different properties into the polyurethane molded product. 2. Form the mold into a predetermined number of split molds, make at least one of the split molds a movable mold that can move forward and backward relative to the other split molds, and place a core on this movable mold to connect it with the other split molds. Claim 1, wherein the core is placed in the cavity by doing this, and the core placed on the movable mold is removed by pulling out the movable mold from another split mold. A method of manufacturing the instrument panel described.