JPH01168413A - Method for manufacturing urethane molding article - Google Patents

Abstract

PURPOSE:To enable the title article to be separated at the same time with the cover even if a main body molding material oozes out to the recess portion of a lower die by setting a projection in a state of being enclosed with a cover to a die during insert molding and separating the cover from the projection after injection material and forming the main body. CONSTITUTION:The cover 30 is made up of 2 (two) pieces 30a, 30b, each piece is integrally connected to the periphery of a rectangular hole 28 in a basement 27 and the peripheral portion in the side surface of the projection 29 through a thin wall portion which is easily destructible (l) and encloses the projection 27, particularly, a through hole 33 as a triangular prism shape. At first, an insert 25 and a resin decorative layer 4 are set in the die 37 and the main body molding material 45 is injected into a cavity 39. The molding material oozed out is adhered to the surface of the cover 30. The die is performed with die opening and the product is separated from the die. Upon pulling to the both sides by pinching the takes 35 of the cover 30, each thin wall portion (l) is destroyed and respective pieces 30a, 30b are separated from the basement 27 and the projection 29 of the insert 25; thus, the molding material layer adhered therein may also be separated.

Description

Detailed Description of the Invention <Industrial Application Field> The present invention provides a urethane molded product comprising a main body made of a polyurethane material and an insert having a protrusion projecting from the main body by insert molding. Regarding the improvement of the manufacturing method, it is suitable for manufacturing, for example, largars, bumpers, etc. for vehicles. Hereinafter, in this specification, explanation will be given by taking a pillar garnish as an example.

<Prior Art> As shown in FIG. 7, the pillar garnish 1 comprises a main body 3 made of foamed polyurethane and an insert 5 made of synthetic resin.The surface of the main body 3 is covered with a resin decorative layer 4. There is.

The insert 5 has a base part embedded in the main body part 3 and a base part embedded in the main body part 3.
It consists of a protrusion 9 that protrudes from. The protrusion 9 is plate-shaped, and has a through hole 11 formed in the center. This through hole 11
The engaging pawl 15 of the clip 13 is engaged with the peripheral edge of the clip 13 . Then, the protruding portion 9 of the pillar garnish 1 is attached to a portion of the pillar of the vehicle (not shown) via the clip 13.

The pillar garnish 1 was formed as follows.

First, the insert 5 is injection molded. Then, as shown in FIG. 8, this is placed in a cavity 19 of a mold 17 made of steel, epoxy resin, or the like. Note that a recess 21 into which the protrusion 9 of the insert 5 can be inserted is formed in the lower mold 17a. At the same time, a resin coating S layer 4 previously formed by vacuum forming, slush molding, etc. is set onto the upper surface inside the cavity 19.

Thereafter, the main body molding material is injected into the cavity 19 to form the main body 3.

<Problems to be Solved by the Invention> However, in the Larger Nitsch 1 obtained by the above manufacturing method, the fluidity of the main body molding material before hardening is high, so that the material flows from between the lower mold f7a and the insert 5 to the protrusion 9. There is a risk that it will seep out and adhere there as shown in Figure 9. Then, the through hole 11 of the protrusion 9 is closed, and the clip 13 cannot be engaged. Therefore, in the past, the layer 23 of the main body molding material that seeped out to the protrusion 9 and adhered thereto was peeled off one by one by hand. However, since the polyurethane used as the main body molding material has strong adhesion to other members, such peeling work is time-consuming.

Therefore, in order to prevent the main body molding material from seeping out before hardening, the portion of the lower mold 17a that forms the recess 21 is replaced with an elastomer material 24 such as silicone resin, as shown in FIG. It is conceivable to improve the adhesion between the mold 5 and the lower mold 17a. However, replacing the lower mold 17a with such an elastomer material 24 is not preferable because the durability of the replaced portion decreases.

Means for Solving the Problems The present invention has been made in view of the above problems, and includes a main body made of polyurethane material and an insert having a protrusion projecting from the main body. This is a method for manufacturing a urethane molded product by insert molding, which is performed by injecting the main body molding material into the cavity of the mold with the insert set in the mold. The insert is set in the mold while being surrounded by a cover, and then a body molding material is injected into the cavity to form the body, and then the cover is separated from the protrusion.

<Examples> The present invention will be explained in more detail below with reference to Examples. Note that the same members as those explained in the conventional example are given the same reference numerals, and the explanation thereof will be partially omitted.

■Preparation of the insert 5 Figure 5.6 shows the insert 25 used in this example. This insert 25 is made of synthetic resin, and the base 2
7. Consists of a protrusion 29 and a cover 30.

The base 27 is plate-shaped, and has a rectangular hole 28 bored in the center. This hole 28 is required for demolding when injection molding the insert. And base 2
A tape 31 covering the hole 28 is attached to the upper surface of the hole 28 to prevent the main body molding material from entering the cover 30 through the string hole z8.

The protrusion 29 is provided on the lower surface of the base 27 and protrudes downward from the periphery of the hole 28 in a vertical direction. A through hole 33 communicating with the hole 28 is provided.

The clip 13 shown in FIG.
will be engaged.

The cover 30 consists of two pieces 30a and 30b, and each piece 30a and 30b is integrally connected to the periphery of the hole 29 in the base 27 and the periphery of the side surface of the protrusion 29 by an easily breakable thin wall portion. has been done. As a result, a cover 30 having a triangular prism-shaped outer shape is formed in the thickness direction of the paper, and the insert 25 with such a structure surrounds the protrusion 27, especially the through hole 33. and the mold from each piece 30a, 30b side,
Can be integrally molded. In addition, the code 35 in the figure is
This is a knob used when separating the cover from the protrusion 29.

The material of the insert 5 is not particularly limited. (2) Setting the insert 25 into the mold (FIG. 1) The insert 25 having the above structure is set into the mold 37. That is, the base 2 is placed in the cavity 39 and the cover 30 is inserted into the recess 41 of the lower mold 37a.

Then, similarly to the conventional example, the resin decorative layer 4 is applied to the cavity 3.
9 Set to the inner top surface.

(2) Step of injecting the main body molding material 45 into the cavity 39 (FIG. 2) The main body molding material 45 is injected into the cavity 39 through a sprue, a runner, and a gate (not shown). This main body molding material is polyurethane and has high fluidity before curing, so the lower mold 37a and the base 2 of the insert 25
7 into the recess 41 and adhere to the surface of the cover 39.

Note that polyurethane does not matter whether it is two-component or one-component, and in the case of zero foamability, whether it is hard or foamable, a chemical foaming method, a physical foaming method, etc. are used.

■ Step a (3.4) of releasing the product, forming the sieve surface layer 4, and separating the cover 30 from the protrusion 29.
figure).

Open the mold 37 and prepare the product (main body 3 + insert 25).
) is released from the mold.

Next, the cover 30 is separated from the protrusion 29.

Separation is performed by pinching the grip portion 35 by hand and pulling it to both sides. Then, each thin section is destroyed,
Each piece 30a, 30b constituting the cover 30 will be separated from the base 27 and protrusion 29 of the insert 25. At the same time, the main body molding material layer 43 adhering to the surface of the cover 30 is also separated.

Note that by reducing variations in the shape of the cover 30, it becomes possible to mechanically separate the cover 30 from the protrusion 29. This is effective from the standpoint of reducing labor when manufacturing long larger dishes in which a large amount of inserts 25 are used.

As a result, the pillar garnish 1 is completed, and the retaining pawl 15 of the clip 13 is engaged with the periphery of the through hole 33 of the protrusion 290.

<Operations and Effects of the Invention> As explained above, the main body made of polyurethane material,
When insert-molding a urethane molded product comprising an insert having a protrusion projecting from the main body, the insert is set in the mold with the protrusion surrounded by a cover, and then the material is poured into the cavity. According to this invention, which is characterized in that the main body is formed by injection, and then the cover is separated from the protrusion, even if the main body molding material, which has high fluidity, seeps into the recess of the lower mold before hardening, , it adheres to the cover on the insert. By separating the cover from the protrusion, the seeping main body molding material can also be separated at the same time.

Here, when compared with peeling off the main body molding material that has adhered to the protrusion from the protrusion (conventional example), separating the cover from the protrusion requires less time and effort.
Depending on the shape of the cover and the manner in which it is connected to the protrusion, the separation work can be performed in a uniform manner. In other words, it becomes possible to mechanically (automatically) separate the cover from the protrusion.

Therefore, according to the present invention, it is possible to reduce the labor and cost of manufacturing urethane molded products.

[Brief explanation of the drawing]

1 to 4 show the manufacturing process of an embodiment of this invention, and the first
2 is a cross-sectional view showing the state in which the insert 25 is set in the mold 37, FIG. 2 is a cross-sectional view showing the state in which the main body molding material 43 is injected into the cavity 39 of the mold 37, and FIG. FIG. 4 is a cross-sectional view showing the pillar garnish 5o of the example, and FIG. 5 is a cross-sectional view of the insert 25 of the example.
6 is a perspective view of the insert 25 with the first piece 30a of the cover 30 separated, FIG. 7 is a sectional view showing the conventional pillar garnish 1, and FIG. FIG.
Cross-sectional view showing the state in which the main body molding material is attached, No. 10
The figure is a cross-sectional view showing the mold 17 of the examined example. 1.50... Pillar garnish (urethane molded product), 3... Main body, 5.25... Insert, 9.29... Projection, 17.37... Mold, 19.39. ...Cavity thread 30...Cover, 45...Main body molding material. Patent filed by Toyoda Gosei Co., Ltd. Figure 1 Figure 7

Claims (1)

[Claims] A urethane molded product comprising a main body made of a polyurethane material and an insert having a protrusion projecting from the main body is placed in the mold with the insert set in the mold. A manufacturing method by insert molding performed by injecting a main body molding material into a cavity, the insert being set in the mold with the protruding part surrounded by a cover integrally connected to the protruding part. A method for producing a urethane molded product, comprising: injecting the main body molding material into the cavity to form the main body; and then separating the cover from the protrusion.