JP3219540B2 - Fiber reinforced plastic fittings - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fiber reinforced resin joint used for joining a high internal pressure pipe such as a water pipe.

[0002]

2. Description of the Related Art In a fiber reinforced resin joint (hereinafter referred to as a fiber reinforced resin), in addition to the corrosion resistance and light weight of a synthetic resin joint, excellent internal pressure (tensile) strength, impact strength, etc. It has.

[0003] In this FRP joint, a continuous fiber impregnated with a resin is wound and laminated on a mandrel, and after the resin is cured, the mandrel is demolded and manufactured, that is, a filament winding method (hereinafter referred to as FW method). The FRP joint formed by the above method can effectively support the internal pressure hoop stress on the fiber and has a particularly high internal pressure strength.

However, the FW method FRP joints are
In particular, when used under pulsating load conditions, for example, when used as a joint for a water pipe, a phenomenon in which water inside leaks in a sweat-like manner, that is, a weeping phenomenon is likely to occur.

In order to prevent such a weeping phenomenon, a molded article made of synthetic resin having anti-weeping is formed by blow molding of polyvinyl chloride or the like, and a joint main body of FW method FRP is formed outside thereof. It is known to provide an anti-weeping layer on the entire inner peripheral surface of a joint (Japanese Patent Application Laid-Open No. 60-229).
742).

[0006]

In a joint, a straight joint (socket), a bend joint, and a pipe having the same diameter are used.
A variety of types such as a T-shaped joint and a cruciform joint are required.

Therefore, in the above-mentioned conventional example, it is necessary to form various kinds of molded articles made of synthetic resin for preventing weeping, so that various kinds of blow molding dies are required, and the production cost becomes high. Also, the management of blow molded products is troublesome.

By the way, when observing the weeping phenomenon of the ordinary FRP pipe joint shown in FIGS. 6A and 6B, the weeping occurs at the portion where the pipe insertion hole is inserted, that is, , Receiving port 12 ', especially taper step surface 12
2 ', water stop rubber ring mounting groove 141', retaining ring mounting groove 142 ', etc. Almost no occurrence is observed.

[0009] This is because local stress due to contact with the tip of the pipe insertion port, stress concentration at uneven portions such as grooves under the action of high internal pressure,
Alternatively, due to local stress due to the contact of the retaining ring, initial microcracks occur at those locations,
It can be inferred that this micro crack propagates in a chain so as to connect the interface between the resin and the fiber, and even if the anti-weeping layer is provided on the entire inner surface of the FRP joint, the insertion contacts The weeping prevention layer at the center of the inner surface of the joint, which does not have any, does not substantially contribute to weeping prevention.

In the above-mentioned conventional example, a molded article made of synthetic resin made of anti-weeping by blow molding is used as a mandrel of the FW, and the operation of removing the mandrel from the mandrel in the normal FW method is omitted, and the molding time is reduced. Although it is shortened, the cost (particularly, mold cost) required for blow molding of various types of anti-weeping synthetic resin molded articles and the management of various types of anti-weeping synthetic resin molded articles are required. Considering the required costs, it is difficult to deny high costs.

An object of the present invention is to reduce the cost of various types of joints having the same diameter, ie, straight joints, bend joints, T-shaped joints, cruciform joints, etc., while ensuring excellent weeping resistance. It is an object of the present invention to provide a fiber reinforced resin joint that can be used.

[0012]

According to the present invention, there is provided a fiber reinforced resin joint according to the present invention, which is a fiber reinforced resin pipe joint and is formed of a synthetic resin made of weeping preventing resin extending from the inlet of the receptacle to the inner end of the receptacle. The molded body is fixedly secured, and has a water-stopping rubber ring mounting groove and a retaining ring mounting groove formed on a weeping-preventive synthetic resin molded body, and has a retaining prevention function. Rubber ring seal for water stoppage
File system.

An example of the present invention will be described below with reference to the drawings. FIGS. 1A to 1D show a straight joint, a bend joint, a T-shaped joint, and a cruciform joint, respectively, according to an embodiment of the present invention.

In FIGS. 1A to 1D, 11 denotes FR.
The joint body part made of P, 12 indicates a socket, and the dimensions of the socket are the same even if the type of the joint is different. Reference numeral 13 denotes a molded article made of synthetic resin that prevents weeping and is fixed to the inner surface of the receiving port 12 and has a length L from the inlet 121 of the receiving port to the end 123 of the tapered step surface 122 at the back of the receiving port. ing. These joints are usually used in an adhesive system (a system in which the space between the receiving port and the pipe insertion port is fixed with an adhesive).

2 (a) to 2 (d) show a linear joint, a bend joint, a T-shaped joint, and a cruciform joint according to another embodiment of the present invention, respectively. A retaining ring mounting groove 142 is formed in the molded article 13 made of synthetic resin that prevents weeping, and is used in a water-stop rubber ring seal system having a function of preventing falling off. 11 is FR
P is a joint main body, 12 is a receiving port, and L is from the inlet 121 of the receiving port 12 in the anti-weeping synthetic resin molded body 13 to the end 123 of the tapered step surface 122 at the back of the receiving port. The length is indicated respectively.

The above-mentioned molded article 1 made of synthetic resin for preventing weeping.
In No. 3, the flexible and easy-to-extend physical properties, contact of the front end of the pipe insertion from the inlet of the socket to the back end, contact of the retaining ring with the inner surface of the socket, or distortion of the groove uneven surface due to internal pressure Even under the occurrence or the like, the occurrence of initial microcracks is prevented.

This molded article 1 made of synthetic resin with anti-weeping property
For 3, various synthetic resins that are more flexible than the joint body 11 made of FRP can be used, but it is preferable to use one having excellent adhesiveness, for example, vinyl chloride.

This molded article 1 made of synthetic resin which prevents weeping
The molding method 3 is a vacuum molding method (plastic
Using a vacuum molding die, vacuum-molding the raw material under reduced pressure under heating and trimming the end surface of the molded product), blow molding method (expanding a barison from the extruder and molding with a blow molding die) And trimming the end surface of the molded product) or injection molding, etc., but in order to guarantee the dimensional accuracy of the insertion of the pipe insertion port into the pipe socket, the injection molding method with excellent inner diameter dimensional accuracy or Preferably, a vacuum forming method is used.

In particular, the molded article 13 made of synthetic resin for preventing weeping used for the joints shown in FIGS.
Has an undercut, it is necessary to use a split mold. A wheel with this undercut
In order to mold the ping-preventing synthetic resin molded article by, for example, a vacuum molding method, a mold 21 having a split structure as shown in FIG. 3A is used, and this mold is formed on a heat-softened plastic plate. 3 and the passage in the mold is evacuated, as shown in FIG.
As shown in (b), the softened plastic plate 131 is suctioned and adhered to the surface of the mold 21, which is cooled and solidified, and the central piece 211 of the divided mold 21 is pulled out.
Withdraw the opposing pieces 212, 212, and finally, oppose pieces 213, 213
, And the both ends of the molded body as shown in FIG.
After trimming, the molding of the molded article 13 made of synthetic resin with anti-weeping is completed.

As the resin of the fiber reinforced resin of the joint body 11, any of a curable resin and a thermoplastic resin can be used, but from the viewpoints of productivity, moldability, etc., use of a curable resin is preferred. Is preferred. Examples of the curable resin include an epoxy resin, an unsaturated polyester resin, a vinyl ester (epoxy acrylate) resin, and a phenol resin.As the thermoplastic resin, polyvinyl chloride, chlorinated polyvinyl chloride, Polyethylene, polypropylene, acrylonitrile-butadiene-styrene copolymer, polystyrene,
Polycarbonate, polyamide, polyvinylidene fluoride, polyphenylene sulfide, polysulfone, polyether / ether ketone and the like can be mentioned.

If necessary, fillers, low-shrinkage agents, modifiers, short fibers, heat stabilizers, plasticizers, lubricants, pigments, and the like can be added to these resins. Joint body 1
As the fibers of the fiber-reinforced resin, organic fibers such as aramid fibers, polyester fibers, and polyamide fibers can be used in addition to inorganic fibers such as glass fibers and carbon fibers.

The fiber content of the joint body 11 is preferably 30 to 95% by volume, and more preferably 40 to 65% by volume, so that the internal pressure resistance and the impact resistance can be ensured. In the present invention, the joint body 11 can be formed by a hand lay-up method or a spray-up method, but from the viewpoints of productivity, moldability, quality stability, etc.
The method is optimal.

The fiber reinforced resin joint of the present invention can be manufactured by using a usual filament winding device shown in FIG. In FIG. 4A, 31 is a roving supply bobbin, 32 is a resin impregnation tank, 33 is a doctor blade, 34 is a feed eye, and 35 is a mold. Is passed through a resin impregnation tank to impregnate the resin, and as shown in FIG. 4B, the rotational speed of the mold 35 and the Y-axis direction of the feed eye 34 (the rotational axis of the mold 35). And the Z-axis direction (the direction in which the feed eye 34 is moved back and forth in a direction perpendicular to the Y-axis) is controlled to set the wrapping angle of the roving to the mold 35 to a predetermined value. The resin impregnated roving is wound around a mold at a predetermined fixed angle by the controlled movement of the feeder, and laminated.

To manufacture the fiber reinforced resin joint of the present invention, for example, the straight joint shown in FIG. 2A by using the filament winding device, as shown in FIG. The spacer 35 shown in FIG.
A molded article 13 made of synthetic resin for preventing weeping is mounted via 1 and the roving is unreeled from the bobbin, passed through a resin impregnation tank, and the resin impregnated roving is passed through a doctor blade to adjust the amount of resin. Then, as shown in FIG. 5B, the laminate is wound and laminated at a predetermined winding angle on a molded article 13 made of anti-weeping synthetic resin and a mold 35, and then wound and laminated by a predetermined amount. Is carried into a heating furnace together with a mold to cure the resin. Thereafter, the mold is removed as shown in FIG. 5C, and the production is completed.

In this case, in order to achieve a strong integration between the anti-weeping synthetic resin molded body 13 and the FW method FRP 11, an adhesive or an adhesive is formed on the outer surface of the anti-weeping synthetic resin molded body 13. It is preferable to apply a surface treatment agent or the like and then perform filament winding. The adhesive or surface treatment agent includes unsaturated polyester resin, epoxy resin, urethane, vinyl ester (epoxy acrylate) resin, etc., but from the viewpoint of adhesive strength and application workability. It is preferable to use a solvent-evaporable one-part urethane treating agent.

In the fiber reinforced resin joint of the present invention,
Molding 13 made of synthetic resin preventing weeping only on the inner surface of the receiving port
However, even if it is bonded, it exhibits excellent weeping resistance and exhibits high internal pressure breaking strength due to the FW FRP joint body 11 having a high fiber content. This is also evident from the results of the hydrostatic pressure tests of Examples and Comparative Examples described later.

[0027]

[Action] Abutting the tip of the pipe insertion port from the inlet to the back end, contacting the rubber ring for water stop and the retaining ring against the inner surface of the inlet, or distortion of the groove uneven surface due to internal pressure The molded article made of synthetic resin that prevents weeping prevents the occurrence of initial microcracks and eliminates the occurrence of weeping.

Further, under the same diameter, a molded article made of synthetic resin made of anti-weeping is commonly used under the same dimensions as the receiving dimensions of various joints such as a straight joint, a bend joint, a T-shaped joint and a cruciform joint. It is possible to reduce the manufacturing cost by using a common molding die for the molded article made of a synthetic resin made of anti-weeping.

[0029]

Examples The joints used in the following examples and comparative examples are shown in FIGS. 2 (a) and 6 (b). , The total length is 420 mm, and the length of the inner surface of the receiving port [FIG.
(A) Length L] is 163 mm, center inner diameter is 154 mm
Is a straight joint.

The resin compositions used in these Examples and Comparative Examples were as follows: resin: 100 parts of an unsaturated polyester resin (viscosity: 7 poise), curing agent: 0.8 parts of methyl ethyl ketone peroxide, curing accelerator: 6% Consisting of 0.3 part of cobalt naphthenate, the continuous fibers used were glass fiber rovings having a count of 2230 g / km.
It is a book, and the method of FW machine used is to rotate the mold,
This is a three-axis system in which the feed eye is moved in the Y-axis direction (the rotation axis direction of the forming die) and the Z-axis direction, and the die used is a straight pipe die having an outer diameter of 150 mm.

Example 1 A molded article made of synthetic resin having anti-weeping was formed by vacuum forming a 3 mm thick vinyl chloride plate. As shown in FIG. 5 (a), this molded article made of synthetic resin having anti-weeping is mounted on a mold, a urethane-based surface treatment agent is applied on the molded article, and then the mold is rotated to form a filter. - the control of the degree, 90 ⁰ and ± 60 ⁰ angle with resin impregnated Garasuro - winding Bing, laminated, the laminate 50 ° C., and cured for 2 hours, the mold was removed from the mold, fibers A reinforced resin joint was manufactured.

Example 2 The procedure of Example 1 was repeated except that the molded article made of synthetic resin having anti-weeping was molded by injection molding of vinyl chloride resin.

Example 3 Example 3 was the same as Example 1 except that the molded article made of synthetic resin with anti-weeping was molded by blow molding of vinyl chloride resin.

[0034] Comparative Example Wie - without using the ping preventing synthetic resin molded body, using a mold of the split, Fi - to the mold-axis direction by controlling the degree at an angle of 90 ⁰ with ± 60 ⁰ The resin-impregnated glass roving was wound and laminated with the same winding amount as in the example, and cured under the same conditions as in the example to produce a fiber reinforced resin joint without a weeping-preventive synthetic resin molded article.

When a hydrostatic pressure test was performed on 10 samples of each of the sample of the example and the sample of the comparative example, weeping occurred at 15 kgf / cm ² (average value) in the comparative example. No weeping occurred even in the product of Example 1 and FRP breakdown occurred.
, 70 kgf / cm ² (average value, the same applies hereinafter), 75 kgf / cm ^{2 in} Example 2, and 65 kgf / cm ² in Example 3.
/ cm ² .

The dimensional accuracy of the inner diameter is ± 0.5 of the comparative example.
mm was ± 0.3 mm in Example 1 and ± 0.1 mm in Example 2, which were both good. In the third embodiment, the accuracy was slightly lower than that of the embodiment, but was not so much as to hinder practical use.

[0037]

The fiber-reinforced resin joint of the present invention has the structure described above, and in view of the fact that weeping frequently occurs in the receiving portion in the conventional fiber-reinforced resin joint, the receiving portion is formed. A molded article made of anti-weeping synthetic resin is fixed only to the inner surface of the mouth, and as long as the bore diameter is the same, a straight joint,
A common anti-weeping synthetic resin molded article can be used between different types of joints such as a bend joint, a T-shaped joint, and a cruciform joint, and the number of molds for the anti-weeping synthetic resin molded article can be reduced. Since the management of the molded article made of synthetic resin that prevents weeping is simplified, it is possible to easily manufacture a fiber-reinforced resin joint having excellent weeping resistance at low cost.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing a different embodiment of the fiber reinforced resin joint of the present invention.

FIG. 2 is an explanatory view showing another embodiment of the fiber reinforced resin joint according to the present invention which is different from the above embodiment.

FIG. 3 is an explanatory view showing an operation procedure of a vacuum forming method of a molded article made of synthetic resin made of anti-weeping used in the present invention.

FIG. 4 (A) is an explanatory view showing a filament winding apparatus used for manufacturing the fiber reinforced resin joint of the present invention, and FIG. 4 (B) is a view showing the feed eye in FIG. 4 (A); It is explanatory drawing which shows a metal mold | die.

FIG. 5 is an explanatory view showing a manufacturing procedure of the embodiment of the present invention.

FIG. 6 is an explanatory diagram showing a different conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Joint main body 12 Reception port 121 Reception port entrance 122 Recess step surface 123 Reception port rear end part 13 Molding made of synthetic resin made of anti-weeping 141 Water stop rubber ring mounting groove 142 Retaining ring mounting groove

Claims (2)

(57) [Claims] 1. A fiber reinforced resin pipe joint, wherein a molded article made of synthetic resin for preventing weeping is fixed to an inner surface of a receiving port from an entrance of the receiving port to a far end of the receiving port. Resin fitting. 2. The fiber reinforced resin joint according to claim 1, wherein a rubber ring mounting groove and a retaining ring mounting groove are formed in the molded article made of synthetic resin that prevents weeping.