JP3384301B2 - Long sandwich molded products - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a long sandwich molded product such as a side molding mounted on the side surface of a door of an automobile.

[0002]

2. Description of the Related Art As a long sandwich molded article such as a side molding, there is one having a core layer coated on the inside and a skin layer resin coated on the outside. In this structure, the core layer is made of a relatively hard core layer resin, and the skin layer resin is made of a relatively soft skin layer resin. Therefore, the surface is soft,
It can have a property of high overall rigidity.

Further, the long sandwich molded article is molded by an injection molding method using a mold. In the above molding, the skin layer resin is first injected from the gate into the cavity of the mold, and then the core layer resin is injected into the skin layer resin. As a result, a long sandwich molded product in which the core layer resin is covered with the skin layer resin is molded.

By the way, as shown in FIG. 8, the long sandwich molded article 9 has a tapered portion 91 whose cross-sectional shape in the width direction Y is gradually thin and a thick thick portion 92. There is. The tapered portion 91 is made of only the skin layer resin 94, and the thick portion 92 is made of the skin layer resin 94 and the core layer resin 95. A general portion 93 having a sandwich structure is provided between the tapered portion 91 and the thick portion 92, and a curved concave portion 931 is provided on the back surface 99 side thereof. The tapered portion 91 and the thick portion 92 have flat adhesive portions 914 and 924 for adhering the long sandwich molded product 9 to the vehicle body.

As described above, the reason why the tapered portion 91 has a structure of only the skin layer resin 94 is that the tapered portion 9 is formed.
The reason for this is that by molding 1 with a relatively soft skin layer resin 94, the tapered portion 91 is brought into close contact with an automobile door or the like.

[0006]

However, in the conventional long sandwich molded article 9 as shown in FIG. 9, the tapered portion 91 side is bent concavely in the longitudinal direction X as shown in FIG. There is a problem that warpage occurs.

That is, the shrinkage rate of the skin layer resin 94 is higher than that of the core layer resin 95. Therefore, the long sandwich molded article 9 is
It contracts more and bends in a concave shape. Therefore, as shown in FIG. 9, the long sandwich molded article 9 is warped in the longitudinal direction X. On the contrary, when the shrinkage rate of the core layer resin 95 is higher than the shrinkage rate of the skin layer resin 94, warpage occurs in the opposite direction to the above.
That is, when there is a difference in shrinkage between the skin layer resin 94 and the core layer resin 95, the long sandwich molded article 9 is bent because it bends to either the tapered portion 91 side or the thick portion 92 side. Warpage occurs in the longitudinal direction X of.

In the long sandwich molded article 90 shown in FIG. 10, the back surface 991 side of the general portion 93 is relatively flat, and the thickness A of the general portion 93 is thicker than that shown in FIG. However, in the case of this shape as well, similarly to the above, warpage occurs in the longitudinal direction X.

The present invention has been made in view of such conventional problems, and an object of the present invention is to provide a long sandwich molded product which does not cause warpage.

[0010]

The invention according to claim 1 has a sandwich structure in which an inner core layer resin is covered with an outer skin layer resin, and one side in the width direction is formed of only the skin layer resin. Is a long elongated sandwich molded product having a thick part made of only the skin layer resin on the other side and a general part having a sandwich structure between the two parts. And a groove portion along the longitudinal direction of the long sandwich molded product, and the thickness B of the remaining portion at the groove forming position is smaller than the thickness A of the general portion. It is a sandwich molded product.

What is most noticeable in the present invention is that the thick wall portion is made of only the skin layer resin, and the back surface side has a groove portion along the longitudinal direction. The thickness B is smaller than the thickness A of the general portion.

Next, the operation of the present invention will be described. In the present invention, the thick portion is made of only the skin layer resin. Therefore, in the long sandwich molded article, both the tapered portion and the thick portion in the width direction are made of only the skin layer resin, and the general portion between them forms a sandwich structure. Therefore, in the long sandwich molded product, the shrinkage ratios in the width direction are balanced with each other, and warpage does not occur unlike the conventional product.

Further, the thick portion has the groove portion along the longitudinal direction of the long sandwich molded article. Therefore, even if the thickness of the skin layer resin in the thick portion is larger than that in the tapered portion, the effect of the shrinkage can be mitigated, and the effect of preventing warpage can be further obtained. Further, the thickness B of the remaining portion between the groove and the design surface of the long sandwich molded product is smaller than the thickness A of the general portion. Therefore, it is unlikely to be affected by shrinkage in the general area. Therefore, the warp of the long sandwich molded product can be further prevented.

Next, the ratio B / A of the thickness B of the remaining portion to the thickness A of the general portion as in the second aspect of the invention.
Is preferably in the range of 0.2 to 0.9. In this case, it is possible to reliably prevent the occurrence of warpage.
A particularly preferable range is that the ratio B / A is 0.3
~ 0.7.

As a method for producing the long sandwich molded article, a protrusion-like weir for forming the groove along the longitudinal direction in a cavity for molding the long sandwich molded article. Using a mold with a section,
There is a method in which the skin layer resin is first injected into the portion forming the general portion, and then the core layer resin is injected into the skin layer resin.

In this case, the skin layer resin first flows into the thick wall portion over the weir portion. Therefore, the thick portion is filled only with the skin layer, and the core layer resin does not enter. Further, the taper portion is formed by the skin layer resin that flows in first, as in the conventional case. Therefore, the sandwich structure is formed only between the thick portion and the tapered portion. According to this example, the long sandwich molded product can be easily molded.

[0017]

DETAILED DESCRIPTION OF THE INVENTION

First Exemplary Embodiment A long sandwich molded article according to an exemplary embodiment of the present invention will be described with reference to FIGS. 1 to 4. As shown in FIGS. 1 and 2, the long sandwich molded article 1 has a sandwich structure in which an inner core layer resin 2 is covered with an outer skin layer resin 3. Further, a tapered portion 11 made of only the skin layer resin 3 is provided on one side in the width direction Y,
On the other hand, there is a thick-walled part 12 made of only the skin layer resin 3,
A general portion 13 having a sandwich structure is provided between the tapered portion 11 and the thick portion 12.

As shown in FIGS. 1 and 2, the thick wall portion 12 has a groove portion 7 which is open to the back surface 19 side and extends along the longitudinal direction X of the long sandwich molded article 1. The thickness B of the remaining portion 17 at the formation position of 7 is smaller than the thickness A of the general portion 13. In addition, the back surface 19
Has a curved dent. In this example, the ratio B
/ A is 0.6.

Also, the tapered portion 11 and the thick portion 12
Have adhesive parts 114 and 124 for attaching the long sandwich molded product 1 to the body or door of an automobile, respectively. The groove portion 7 is provided in the middle of the adhesive portion 124 of the thick portion 12.

Next, the molding of the long sandwich molded article 1 will be described with reference to FIGS. First, a cavity 60 for molding the long sandwich molded article 1
Are formed by the molds 61 and 62. The mold 61,6
2, the gate 66 is opened at the portion corresponding to the base end portion in the longitudinal direction X.

As shown in FIG. 3, the die 61 has a concave cavity wall 618 for forming the design surface (front side surface) 18 of the long sandwich molded article 1. On the other hand, the mold 62 has a convex cavity wall 629 for forming the back surface 19 of the long sandwich molded product 1, and a protruding weir for molding the groove portion 7 along the longitudinal direction X. A section 627 is provided. Incidentally, reference numeral 624 in the drawing is a cavity wall for molding the adhesive portions 114, 124.

In molding the long sandwich molded article 1, as shown in FIG. 4, first, the skin layer resin 3 is injected from the gate 66 into the cavity 60, and then the skin layer resin 3 is injected. The core layer resin 2 is injected therein. As a result, the core layer resin 2 pushes the skin layer resin 3 from the inside. Then, the long sandwich molded article 1 in which the core layer resin 2 is covered with the skin layer resin 3 is molded.

At the time of molding, the core layer resin 2
The skin layer resin 3 pushed by is shown in FIGS. 4 (A) and 4 (B).
As shown in FIG. 5, the mold 62 is passed over the dam portion 627 and flows into the thick portion cavity 612. Then, the skin layer resin 3 is deprived of heat by the mold 62 to increase its viscosity and solidify to form the thick portion 12. On the other hand, in the tapered portion cavity 611, since the space between the molds 61 and 62 is narrow, the skin layer resin 3 that has flowed into this portion first is deprived of heat and solidified to form the tapered portion 11.

Therefore, a sandwich structure composed of the skin layer resin 3 and the core layer resin 2 enclosed therein is formed in the general portion cavity 613 between the thick portion cavity 612 and the tapered portion cavity 611. To be done.

Next, the operation of this example will be described. In the long sandwich molded article 1 of this example, the thick portion 12 is made of only the skin layer resin 3. Therefore, both the tapered portion 11 and the thick portion 12 are made of only the skin layer resin 3, and the general portion 13 between them forms a sandwich structure. Therefore, in the long sandwich molded product 1, the shrinkage rates in the width direction Y are balanced with each other, and unlike the conventional product, no warpage occurs in the longitudinal direction X.

The thick portion 12 has the groove portion 7 along the longitudinal direction X of the long sandwich molded article 1. Therefore, even if the thickness of the skin layer resin 3 in the thick portion 12 is larger than the thickness of the skin layer resin 3 in the tapered portion 11, the amount of the skin layer resin 3 in the thick portion 12 is changed to the skin layer of the tapered portion 11. Since the amount of resin 3 can be approached,
The effect of the shrinkage ratio can be alleviated, and the effect of preventing warpage can be further obtained.

Further, the thickness B of the remaining portion 17 between the groove 7 and the design surface 18 of the long sandwich molded article 1
Is smaller than the thickness A of the general portion 13. Therefore, it is difficult to be affected by the contraction in the general portion 13. Therefore, warpage of the long sandwich molded article 1 can be further prevented.

Further, according to the above-mentioned molding method, the excellent long sandwich molded article as described above can be easily molded.

Embodiment 2 In this embodiment, as shown in FIGS. 5 and 6, the adhesive portion 114 of the tapered portion 11 and the adhesive portion 1 of the thick portion 12 are used.
24, three linear protrusions 125 are provided along the longitudinal direction X. Further, the height H of any of the six linear projections 125 is shorter than the depth D of the groove 7. The other configurations and shapes are the same as those of the first embodiment.

In this case, the linear protrusion 125 is
When the long sandwich molded article 10 is bonded to the vehicle body by using a double-sided tape (not shown), it is possible to prevent the design surface 18 on the side opposite to the bonding portion 124 from having a recess. In addition, also in this example, the same operational effects as those of the first embodiment can be obtained.

Embodiment 3 In this embodiment, the back surface 191 is flat as shown in FIG.
Each of the adhesive portions 114 and 124 is provided with two linear protrusions 125. Others have the same shape and structure as those of the second embodiment.

Also in this case, the long sandwich molded article 1
In No. 5, the contraction rates in the width direction Y are balanced with each other, and unlike the conventional product, no warpage occurs in the longitudinal direction X. In addition, also in this example, the same operational effect as that of the second embodiment can be obtained.

[0033]

As described above, according to the present invention, it is possible to provide a long sandwich molded article which does not warp.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional perspective view of a long sandwich molded product according to a first embodiment.

FIG. 2 is a perspective view of the back surface side of the long sandwich molded article in the first embodiment.

FIG. 3 is a cross-sectional view of a mold for a long sandwich molded product according to the first embodiment.

FIG. 4 is an explanatory view of a method for molding a long sandwich molded article in the first embodiment.

FIG. 5 is a partial cross-sectional perspective view of a long sandwich molded product according to the second embodiment.

FIG. 6 is a perspective view of the back surface side of the long sandwich molded article in the second embodiment.

FIG. 7 is a partial cross-sectional perspective view of a long sandwich molded product according to the third embodiment.

FIG. 8 is a partial cross-sectional perspective view of a long sandwich molded product in a conventional example.

FIG. 9 is an explanatory view showing a problem of a long sandwich molded product in a conventional example.

FIG. 10 is a partial cross-sectional perspective view of another long sandwich molded product in the conventional example.

[Explanation of symbols]

1. ． ． Long sandwich molding, 11. ． ． Taper, 12. ． ． Thick part, 13. ． ． General department, 17. ． ． Remnants, 2. ． ． Core layer resin, 3. ． ． Skin layer resin, 61, 62. ． ． Mold, 611. ． ． Tapered cavity, 612. ． ． Thick wall cavity, 613. ． ． General part cavity, 7. ． ． Groove, A, B. ． ． Thickness,

Front page continuation (72) Inventor Hiroshi Mukai 1 Ochiai, Nagachibata, Kasuga-cho, Nishikasugai-gun, Aichi Prefecture, within Toyoda Gosei Co., Ltd. (56) Reference JP-A-4-246534 (JP, A) JP-A-4-164616 (JP, A) JP-A-5-69456 (JP, A) JP-A-2-206517 (JP, A) Actual development Sho 59-187425 (JP, U) (58) Fields investigated (Int. Cl. ⁷⁾ , DB name) B29C 45 / 16,45 / 26 B60R 13/04

Claims (2)

(57) [Claims] 1. A sandwich structure in which an inner core layer resin is covered with an outer skin layer resin, wherein one side in the width direction is a tapered portion made of only the above skin layer resin, and the other is a skin layer resin. A long-sized long sandwich-molded product having a thick-walled part consisting of only one and a general part having a sandwich structure between the two parts. A long sandwich molded product having a groove portion along the longitudinal direction of the product, wherein the thickness B of the remaining portion at the groove forming position is smaller than the thickness A of the general portion. 2. The thickness A of the general portion according to claim 1.
The ratio B / A of the thickness B of the remaining portion to
A long sandwich molded article characterized by being in the range of 0.9.