JPH04179536A - Inner mold for molding frp pipe joint and method for molding and demolding frp pipe joint using the same - Google Patents

Abstract

PURPOSE:To enhance dimensional accuracy and to facilitate demolding by separately forming a receiving mouth mold and a body mold in a divided state. CONSTITUTION:An inner mold 1A for molding an FRP pipe joint consists of receiving mouth molds 2, 3 and a curved pipe-like body mold 3 separately formed in a divided state and the end connection parts 2a, 2a of the receiving mouth molds 2, 2 and the end connection parts 3a, 3b of the body mold 3 are fitted each other to mold an FRP pipe joint. A filling member 11 is attached to the end connection part 2a of the receiving mouth mold 2 so as to become flush with the outer peripheral surface of said connection part 2a and the generation of wrinkles in the inner surface of a molded product by the expanding/contracting action of the inner mold 1A and a tape 9 in a heat-curing and cooling process is suppressed. A degassing nozzle 7 is provided to one end part of the body mold 3 and a hot-melt adhesive is applied to the contact part of the receiving mouth mold 2 and the body mold 3 and the fixing tape 9 is wound around the outer peripheral surface of the contact part to form the inner mold 1A having an integral shape. The receiving mouth mold 2 is easily separated from the body mold 3 by twisting the mold 2 around the axial center thereof and buckled by drawing out the air in the body mold 3 to make it possible to easily perform demolding. Further, it is pref. to soften the inner mold under heating at the time of buckling under suction.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention is utilized in the technical field of molding fiber-reinforced thermosetting resin (hereinafter referred to as FRP) in which glass fibers are impregnated with a thermosetting resin material. In particular, the present invention relates to an inner mold for molding an FRP pipe joint and a method for molding an FRP pipe joint using this inner mold.

(Prior art) As this type of internal mold, conventionally, for example, Japanese Patent Application No. 63-2
The one described in Japanese Patent No. 48645 is known.

For example, the T-shaped inner mold P disclosed in Japanese Patent Application No. 63-248645 has P+, Pz as shown in FIG.
. Then, a hemispherical inner mold support end is integrally bulged from the socket end face molding part d located at the tip of each body part a, and the spherical surface of this inner mold support end is molded. Deaeration nozzles C are provided at appropriate locations. Furthermore, the end opposite to the inner mold support end is formed into inclined joint surfaces e, e, f, f, and a fitting protrusion (not shown) provided on the inclined joint surface e and the inclined joint surface f. A T-shaped inner mold P is obtained by fitting a fitting recess (not shown) provided in the inner mold P.

However, the inner mold P disclosed in Japanese Patent Application No. 63-248645 has increased rigidity due to the lip effect caused by the inclined joint surfaces e and f. Therefore, after molding the FRP pipe joint, each inner mold P2. Even if a suction means is connected to the degassing nozzle C... to Pz and Pz to reduce the pressure inside the T-shaped inner mold P, it is not possible to easily buckle the mold, making demolding work extremely time-consuming. Ta. - Therefore, the applicant has developed an FR that solves this problem.
We have developed an inner mold for forming P-pipe joints (see Utility Model Application No. 32283/1993).

The inner mold g described in this Japanese Utility Model Publication No. 2-32283 is formed by separately forming the socket mold g, g and the assembly mold as shown in FIG. End joint part i of mouth type g
By fitting and joining the end joint portions (not shown) of each set of molds to the inside of the mold, a bent tubular inner mold g is formed into an integral shape, and then it is wrapped around the end joint portion i. A tape (not shown) that covers the outer periphery of the annular recess j provided is extended and wrapped around the outer periphery of the end of the mold, thereby correcting the level difference in the end joining portion i.

However, the tape (not shown) wrapped around the outer periphery of the annular recess j can prevent the resin from entering the annular recess j during molding of the FRP pipe joint, but it can prevent resin from entering the annular recess j after molding is completed. In the cooling process, the inner mold g and the tape expand and contract, causing wrinkles on the inner surface of the molded product, resulting in a problem of reduced dimensional accuracy.

In view of such conventional circumstances, the present invention provides an inner mold for molding FRP pipe joints that has high dimensional accuracy, is easy to demold, and can reduce the manufacturing cost of the inner mold, and this inner mold. The purpose of this paper is to provide a method for molding and demolding FRP pipe joints.

(Means for Solving the Problems) The inner mold for molding an FRP pipe joint of the present invention is an inner mold for molding a FRP pipe joint made of a hollow body made of synthetic resin, and is divided into a socket mold and a set mold. A deaeration nozzle is provided at one end of the assembly mold, and the socket mold and assembly mold are joined to form a predetermined shape before forming the FRP pipe joint. .

In addition, a method for molding and demolding an FRP pipe joint using this inner mold is to use a fiber-reinforced thermosetting resin in which glass fiber is impregnated with a thermosetting resin in the inner mold for forming an FRP pipe joint according to claim 1. After winding the resin and heating and hardening it to form a molded product, the inner mold is heated and softened, and the socket mold is held between clamping tools and twisted around the axis to reduce its diameter and removed from the mold. After that, a suction means is connected to the degassing nozzle of the mold, the air inside the body mold is suctioned and degassed to buckle the mold, and the buckled mold is pulled out from the molded product and degassed. It is something to be molded.

(Function) By dividing the inner mold into a socket mold and a set mold, it becomes possible to standardize the inner mold.

In addition, by forming the mold so that not only a portion of each corner but also the entire part is rounded, it is possible to prevent the formation of localized high-rigidity parts, and therefore, buckling due to vacuum pressure can be easily performed. As a result, the mold can be removed quickly.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

Inner mold IA for forming FRP pipe joints shown in Figures 1 to 3
In this case, the socket molds 2, 2 and the curved tube-shaped set mold 3 are separately formed.

Then, by fitting and joining the end joint parts 2a, 2a of the socket mold 2.2 and the end joint parts 3a, 3a of the body mold 3, as shown in FIG. is formed.

In this way, by using the inner mold IA formed into an integral shape by joining the socket molds 2, 2 and the body mold 3, a bent tubular F is formed.
RP pipe joints are formed.

The joining structure between the socket mold 2 and the body mold 3 is as shown in FIG.
An annular protrusion 4 having a diameter smaller than that of a and abutting on the inner surface of the end joint portion 2a of the socket mold 2 on the end joint portion 3a of the body mold 3.
．． 5 is provided.

Further, the annular protrusion 4 is placed at the location where the annular protrusion 4 on the tip side of the end joint portion 2a of the socket mold 2 is located.
An annular recess 6 is provided along the slope 4a on the tip side. In this annular recess 6, a filling member 11 is inserted into the socket mold 2.
It is attached so that it is flush with the outer circumferential surface of the end joint portion 2a.

This filling member 11 is used to prevent wrinkles from forming on the inner surface of the molded product due to the expansion and contraction of the inner mold IA and tape 9, which will be described later, during the heat curing and cooling process after the molding of the FRP pipe joint is completed. , an elastic material such as annular rubber is applied, and its cross-sectional shape is, for example, in the case where the annular recess 11 is U-shaped, a U-shape (Fig. 7), a V-shape (Fig. 8),
Hollow cylindrical shape (Fig. 9), oval shape slightly protruding from the outer peripheral surface of the end joint part 2a (Fig. 1O), and end joint part 2
It is formed by selecting either a hollow cylindrical shape (FIG. 11) that slightly protrudes from the outer circumferential surface of a.

Furthermore, as shown in FIG. 3, one end of the body mold 3 is provided with a deaeration nozzle 7 to which a suction means (not shown) such as a vacuum pump is connected.

When the socket mold 2 and the body mold 3 are joined together, when the end joint part 3a of the trunk mold 3 is inserted into the end joint part 2a of the socket mold 2, the tip of the annular protrusion 4 of the trunk mold 3 is inserted. The side slope 4a abuts the inner slope 6a of the annular recess 6 of the end joint portion 2a of the socket mold 2. It is possible to increase the adhesive strength by applying an adhesive to this contact portion in advance.

Further, by making surface contact in this manner, the axes of the barrel mold 3 and the socket mold 2 can be easily aligned.

On the other hand, the tip 2b of the end joint portion 2a of the socket mold 2 is connected to the body mold 3.
It abuts against the stepped portion 8 of the end joint portion 3a.

An adhesive such as Honmelt is applied to this contact area,
This part is fixed.

Further, a protrusion 4 provided at the end joint portion 3a of the body mold 3
, 5 are in contact with the inner surface of the end joint portion 2a of the socket mold 2,
In this state, the fixing tape 9 is wrapped around the outer circumferential surface and the end joint part 2a of the socket mold 2 and the end joint part 3a of the body mold 3 are joined and fixed, and the integrated inner mold IA is It is formed.

The fixing tape 9 also serves to prevent resin from entering the inner mold IA or the annular recess 6 during molding of the FRP pipe joint.

After forming the FRP pipe joint with this inner mold IA, the socket mold 2 can be easily separated and removed from the adhesive surface with the body mold 3 by twisting around the axis. Subsequently, a suction means (not shown) is connected to the deaeration nozzle 7 of the body mold 3,
By extracting the air inside the body mold 3 and causing it to buckle,
Can be easily demolded. In addition, it is preferable that the inner mold is heated and softened when performing suction buckling.

Inner mold IB for forming FRP pipe joints shown in Figures 4 and 5
As with the inner mold IA, the socket mold 2゜2.2 and the body mold 1 are
0 are formed separately, and the socket type 2. 2
．． 2 end joint portion 2 a + 2 a + 2 a,
By fitting and joining the end joint portions 10a, 10a110a of the body mold 10, a T-shaped inner mold IB as shown in FIG. 4 is integrally formed.

When molding an FRP pipe joint using this inner mold IB,
A molded article is obtained through the same procedure as in the case of the inner mold IA described above.

(Effects of the Invention) In the inner mold for molding an FRP pipe joint of the present invention, the socket mold and the body mold are divided and formed separately, and since the socket mold is made independently, it has a symmetrical shape and dimensions. Accuracy can be improved. Therefore, when molding FRP pipe joints of different lengths and shapes, it is possible to share the socket type,
The more the production cost increases, the more significant the cost reduction becomes.Moreover, the number of molds for producing the inner mold can be reduced, and the amount invested in molds can be suppressed. moreover,
There is little variation in wall thickness, the accuracy of the inner diameter is improved, and the fitting accuracy between the socket mold and the assembly mold is extremely high.

In addition, the method for forming and demolding FRP pipe joints using this inner mold is that the inner mold is integrally formed with the shape of the assembled mold not only in a part of each corner but also in a rounded shape as a whole. It is possible to avoid an increase in rigidity due to the rib effect as in the conventional case. Therefore, after removing the inner mold from the socket mold by twisting, the assembly mold can be easily buckled and removed by vacuum pressure, which significantly improves the workability of forming FRP pipe joints. It has great advantages.

[Brief explanation of drawings]

The drawings show embodiments of the invention, and include FIGS. 1 and 4.
The figure shows a front view of the inner mold for forming FRP pipe joints, Figure 2 is a front view of the socket mold, Figures 3 and 5 are front views of the assembly mold, and Figure 6 shows the relationship between the socket mold and assembly mold. A longitudinal sectional view of the main part showing the joint shape, FIGS. 7 to 11 are longitudinal sectional views showing each side of the filling member,
FIGS. 12 and 13 are front views showing previous examples of inner molds for forming FRP pipe joints. IA, IB...Inner mold for FRP pipe joint molding 2...Socket mold 2a...End joint portion 3.10...Assembly mold
6... Annular recess 7... Deaeration nozzle 11... Filling member patent applicant Sekisui Chemical Co., Ltd.
Okayama Sekisui Kogyo Co., Ltd. Representative Patent Attorney Hiroshi Onishi Figure 1
Figure 2 Figure 6 d Figure 7 Question 8 Figure 9 Figure 10 LA Figure 11 Figure 12 Lawn 13) 2I

Claims (1)

[Scope of Claims] 1) An inner mold for molding an FRP pipe joint made of a hollow body made of synthetic resin, wherein a socket mold and a body mold are divided and formed separately, and one end of the body mold is formed separately. An inner mold for forming an FRP pipe joint, characterized in that a deaeration nozzle is provided in the inner mold, and the socket mold and the body mold are joined to form a predetermined shape before molding the FRP pipe joint. 2) A fiber-reinforced thermosetting resin obtained by impregnating glass fiber with a thermosetting resin was wound around the inner mold for molding the FRP pipe joint according to claim 1, and this was heated and cured to form a molded product. After that, the inner mold is heated to soften it, and the socket mold is held between clamping tools and twisted around the axis to reduce its diameter and removed from the mold, and then a suction means is connected to the degassing nozzle of the body mold. An inner mold for forming an FRP pipe joint is used, which is characterized in that the air in the body mold is suctioned and deaerated to cause the body mold to buckle, and the buckled body mold is pulled out from the molded product and removed from the mold. Method for molding and demolding FRP pipe joints.