JP2003291864A - Aeropart for automobile formed by foaming using dicyclopentadiene resin - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an aeropart for an automobile formed by foaming by which uniform fine foam is obtained even in a large aeropart produce such as an air deflector, an appearance thickness drop is prevented, and a rib and a boss part can be formed on a required part of the product. <P>SOLUTION: The physical properties of material and appearance quality required by a large product such as an air deflector are secured, and also in order to reduce the weight by foaming, foaming is performed at a foaming magnification of 1.05 to 2.0 and with a foam cell diameter of 100 μm using dicyclopentadiene resin. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aero part that is attached to a roof panel of a cabin of a truck and controls the flow of air by being attached to the outside of the vehicle such as an air deflector that rectifies the flow of air. When foam molding is performed using dicyclopentadiene resin, foam with a fine cell diameter is uniformly obtained, while ensuring high strength,
RIM that is lightweight and effective for improving the appearance design
(Reaction Injection Molding) The present invention relates to a molding method and an aero part for an automobile thus obtained.

[0002]

2. Description of the Related Art Conventionally, foam molding has been widely adopted for the purpose of reducing the weight of resin molded products. However, the conventional foaming method that mixes a large aero parts product such as an air deflector with a chemical foaming agent or gas mechanically results in a large foam cell diameter or non-uniform foaming. Even in this case, there are problems that the physical properties of the material are remarkably deteriorated and the appearance and design are deteriorated. In particular, if the foam cells are large, the strength of that part is significantly reduced, and the product shape itself may not be obtained due to sink marks in the product thick part, and if the foaming is uneven, the variation in product weight is large, We were unable to create stable product quality.

[0003]

SUMMARY OF THE INVENTION In view of the technical problems of the above prior art, the present invention can obtain uniform and fine foaming even in a large aero parts product such as an air deflector, and prevent appearance of sink marks. Accordingly, it is an object of the present invention to provide an aero parts product for automobiles, which is formed by foaming and is capable of forming ribs and bosses at necessary parts of the product.

[0004]

The present invention uses a dicyclopentadiene resin in order to reduce the weight by foam molding while ensuring the material properties and appearance quality required for large products such as air deflectors. Foaming ratio 1.05-2.
There is a technical point in that it is molded to 0 times and a foam cell diameter of 100 μm or less.

As a method for producing the same, the first container is filled with a liquid A containing dicyclopentadiene and a stable catalyst as main components, and dicyclopentadiene, a catalyst activator and a polymerization initiator as main components. Fill the second container with the liquid B, and
After injecting a predetermined gas into the liquid and the liquid B, they were mixed, injected into a molding die, and foam-molded.

Here, the liquid A is divided into a liquid containing dicyclopentadiene and a stable catalyst as main components and a liquid B containing dicyclopentadiene, a catalyst activator and a polymerization initiator as main components. The purpose is to inject and saturate CO ₂ gas, N ₂ gas, Ar gas, etc. in a state where the polymerization reaction does not occur with the liquid or the B liquid alone. Therefore, in addition to the metal catalyst, a stabilizer for stabilizing the catalyst is added to the liquid A, if necessary. If necessary, in addition to the catalyst activator and the polymerization initiator, a stabilizer of the polymerization initiator and the like are added to the liquid B so that the polymerization reaction is started only after being mixed with the liquid A.

When the injected gas is CO ₂ gas,
At a normal temperature of about 20 ° C. and a pressure of about 60 to 80 atm, the state becomes so-called a critical fluid. Further, in the case of N ₂ gas, it becomes a critical fluid state at about 30 atm, but since the dissolution rate is slower than that of CO ₂ gas, it is about 100 to 120.
It is injected at atmospheric pressure. In this way, the respective liquids are sent from the first container filled with the liquid A and the second container filled with the liquid B into the mixing chamber, and the liquids are made into a uniform liquid by collision mixing at the time of discharge, It is injected into the mold.

As described above, it is preferable to apply a back pressure of 0.1 to 0.5 MPa when the mixed solution is injected into the mold. Further, in order to keep the cavity pressure constant, it is necessary to release the pressure at the time of injection, and a relief valve or the like is used so that the optimum curing pressure is always maintained. The back pressure supply port is selected and arranged at a predetermined portion in the cavity according to the size and shape of the product. Here, the back pressure is 0.1 MPa
When the amount is below, the skin layer is easily molded and the surface property is improved, but the foaming rate and the physical properties of the material are deteriorated. On the other hand, when the back pressure is 0.5 MPa or more, the foamed cell diameter becomes small, the cell density becomes high, and the physical properties are improved, but in the case of a large product, it is likely that the end portion of the cavity cannot be completely filled. .

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. FIG. 5 shows a configuration example of a resin molded part of the air deflector. In trucks equipped with box-shaped panel vans, it is common for a step to occur between the roof panel of the cabin and the front of the box-shaped panel van. Attached to the panel is an air deflector as shown in FIG. Therefore, such an air deflector has to correspond to the size of the roof panel of the truck and thus becomes a large product. Further, since the product is mainly intended to rectify the flow of air, reduce the air resistance, and improve the fuel consumption, if it is not light, the fuel consumption will be worsened. On the other hand, strength is also required because it directly receives air resistance.

In the example of the air deflector shown in FIG. 5, a front cover 2 is attached to the front portion of a main body 1 called a drag, and a flap 3 is attached to the rear portion. Therefore, as shown in FIG. 4, it is necessary to form the boss portion 1b into which the nuts or bolts for attaching these parts and for attaching to the roof panel are inserted in the main body 1, as shown in FIG. An example of the shape of the boss portion is shown in FIG. Further, in order to secure the strength of the main body 1, a rib portion 1a is formed as shown in FIG. In the conventional foam molding, when such a rib portion is provided on the back side of the product, that portion becomes thick, and a sink mark is apt to occur on the surface side, so that a large rib as shown in FIG. 3 cannot be set. . According to the molding method of the present invention described below, it is possible to easily mold the boss portion and the rib as described above without a sink mark.

FIG. 1 shows a schematic diagram of a molding method for obtaining a large aero parts product such as an air deflector according to the present invention. The first container 4 is filled with dicyclopentadiene as a liquid A and a stabilized metal catalyst. On the other hand, the second container 5 is filled with liquid B such as dicyclopentadiene, a catalyst activator, and a polymerization initiator. In the case of CO ₂ gas, 60 to 80 atmospheric pressure is applied to the first container and the second container for saturation injection. Further, in the case of N ₂ gas, 100
Saturate injection at ~ 120 atm. Next, the liquid A and the liquid B are sent to the mixing chamber 7 by a pump or the like, uniformly mixed in this mixing chamber, and then injected into the mold 10 by the mixed liquid sending means 6. FIG. 2 shows the structure of the mold 10. In FIG. 2 (a), the cavity mold 1
1 is a perspective view, and FIG. 2B shows the positional relationship with the core die 12 together with the aa sectional view. Cavity mold 1
1, a seal rubber member 13 that seals when closed with a core mold 12 is provided, and a back pressure gas supply unit 14 that faces a filter tube 17 for applying a back pressure of N ₂ gas or the like is provided inside thereof. Has been. In addition, here the filter tube 17
The reason for using is to prevent the resin from entering. A reservoir portion 15 is provided between the back pressure gas supply portion and the product portion 1 as a resin reservoir for ensuring the product shape and physical properties. The core mold 12 and the cavity mold 11 are closed, and N ₂ gas is supplied from the back pressure gas supply pipe 16 in an amount of 0.1 to 0.
When 5 MPa is applied and the mixed resin of liquid A and liquid B is injected from the injection port 18 into the cavity 11a, the expansion ratio is 1.05
An air deflector having a foam cell diameter of 100 μm or less was obtained at 2.0 times.

[0012]

According to the present invention, when RIM molding is performed using dicyclopentadiene resin while applying a predetermined back pressure, a plurality of ribs are formed in the main body of the air deflector, and assembling of components and roof panel mounting are performed. It is possible to form a boss part for use, and there is no sink mark in the thick part,
An air deflector with excellent appearance and high strength can be obtained.

[Brief description of drawings]

FIG. 1 shows a schematic diagram of a RIM molding method according to the present invention.

FIG. 2 shows an example of a molding die for an air deflector according to the present invention.

FIG. 3 shows a setting example of ribs of an air deflector.

FIG. 4 shows a setting example of a boss portion of an air deflector.

FIG. 5 shows an example of an air deflector.

[Explanation of symbols]

1 Air deflector body 2 Front cover 3 flaps 4 first container 5 Second container 6 Mixed liquid feeding means 7 mixing chamber 10 mold 11 cavity type 12 core type 13 Seal rubber member 14 Back pressure gas supply section 15 Reservoir section 16 Back pressure gas supply piping 17 Back pressure gas supply filter tube 18 Mixed liquid injection port

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) B29K 105: 04 B29K 105: 04 F term (reference) 4F206 AA12 AB02 AB04 AG20 AH17 AR02 AR20 JA01 JA04 JM05 JN22 JN27 4J032 CA38 CB01 CD01 CE06 CG07

Claims (4)

[Claims] 1. An aero part for an automobile, which is obtained by foam molding using a dicyclopentadiene resin. 2. The aero parts for automobiles according to claim 1, which has a foaming ratio of 1.05 to 2.0 and a foaming cell diameter of 100 μm or less. 3. A liquid A containing dicyclopentadiene and a stable catalyst as main components is filled in a first container, and B containing dicyclopentadiene, a catalyst activator and a polymerization initiator as main components.
The liquid is filled in a second container, and a predetermined gas is injected into the liquid A and the liquid B, which are mixed and injected into a molding die to be foam-molded. Aero parts for automobiles described. 4. When the foam molding according to claim 3 is carried out,
Aero parts for automobiles, characterized by applying a back pressure of 1 to 0.5 MPa.