JPS60129225A - Manufacture of coupler having corrosion-resistant inner and outer faces - Google Patents

Abstract

PURPOSE:To obtain a coupler having corrosion-resistant inner and outer faces by a method in which a coupler is set in split molds, a slide core is inserted into the coupler to form a cavity between the periphery of the coupler and the molds and also between the inner surface of the coupler and the core, and a resin is injected to cover the inner and outer faces of the coupler. CONSTITUTION:A metal coupler 22 to be coated with a resin is set in split molds 2, and a slide cores 8-9 are inserted into the opening 3 of the molds 2. Thereby, an outside cavity 3B is formed between the coupler 22 and the molds 2, and an inside cavity 3A is formed between the coupler 22 and the cores 8-10. A molten resin is injected into the cavities 3A and 3B to obtain the coupler whose inner and outer faces are covered with the resin.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing an anti-corrosion joint whose inner and outer surfaces are lined with synthetic resin layers.

Conventional anti-corrosion fittings are generally made of metal and have only the inner or outer surface lined with synthetic resin. /, the inner and outer surfaces of the joint can be completely sealed by simply screwing together the jointed pipes without any special anti-corrosion measures during construction. An anti-corrosion joint on the inside and outside surfaces has been proposed.

Without further ado, such a corrosion-resistant inner and outer joint will be briefly explained with reference to FIG. 5, which is a longitudinal cross-sectional view of an example of the corrosion-proof joint and a joint pipe in a connected state.

In the figure, reference numeral 21 denotes a corrosion-proof joint on the inner and outer surfaces, and a tapered thread 23 is formed on the inner surface of each end of a T-shaped metal joint body 22. is in a floating state with a gap 24,
A synthetic resin layer 25 such as vinyl chloride resin is formed in two innings. Further, a similar synthetic resin layer 26 is formed as a lining over the entire outer surface of the joint main body 22, and its end portion protrudes beyond the end surface of the main body 22, and the inner surface of the protruding portion is formed in a tapered shape. On the other hand, the fitting pipe 30 has a pipe body 32 made of a steel pipe, a cast iron pipe, etc., which has a tapered thread 31' on the outer surface of the end, and the entire inner and outer surfaces except for the tapered thread 31 are covered with a synthetic resin layer 33 similar to the above. It has a lining.

Therefore, if such a joint pipe 30 is screwed and connected to the thread 23 of the joint 21 with its thread 31, the outer diameter DL of the fitting portion corresponding to the thread 23 of the resin layer 25 that has been internally lined on the joint 21 in advance is By making the inner diameter d□ of the joint pipe 30 slightly larger at the base, and by making the inner diameter D2 of the protruding portion of the resin layer 26 slightly smaller at the base than the outer diameter d2 of the joint pipe 3o, it is possible to The inner and outer surfaces are pressed together and the joint is completely sealed. In this case, adhesive is preferably applied to these crimped parts. In this way, the anti-corrosion joint 21 and the joint pipe 3o, which have been subjected to anti-corrosion treatment on the inner and outer surfaces, are tightly joined, and the metal part at the joint is not exposed on the inner and outer surfaces and is completely covered with the synthetic resin layer. , exhibits extremely good anti-corrosion effects.

The present invention aims to provide an extremely simple and reliable method for lining the inner and outer surfaces of the metal joint body with synthetic resin for the above-mentioned inner and outer anti-corrosion joint 21 as an example, and is based on the drawings below. The method of the present invention will now be described in detail.

In order to explain the method of the present invention, Fig. 1 is an example of the main part of the mold, with the fixed side mold plate of the split mold as an example omitted, and the main body of the joint to be lined set in place, with a part of the main part mold shown in cross section. FIG. 2 is a partially sectional plan view of the mold shown in FIG. 1 when the split mold is closed and ready for injection of synthetic resin. In this case, a case will be described below in which the above-mentioned inner and outer anti-corrosion joint 21 is manufactured, but the parts of the joint body 22 that have already been described will be given the same reference numerals and the description thereof will be omitted.

In Figures 1 and 2, 1 is a split mold, 2 is a movable mold plate thereof, and a joint body 22 to be lined is placed in the mold 2 with a gap necessary for lining the resin. A cavity 3 for installation is formed. In addition, in the portion of the cavity 3 of the mold 2 where the joint body 22 is disposed, there is a movable magnet 4 that can protrude into the cavity 3 or be retracted so as to coincide with the wall surface forming the cavity 3. 3
They are arranged individually and are configured to move in and out in conjunction with the opening and closing operations of the movable mold plate. In this case, one magnet 4 is disposed at each central portion of the outer surface of the T-type joint body 22 corresponding to each connection port to support the joint body 22.
For joints such as elbows and bushes, two to three or more joints may be placed in suitable positions for supporting the corresponding molds. Further, in order to determine the set position of the joint body to be lined, it is preferable that position fixing protrusions (not shown) are arranged so as to be able to move in and out in conjunction with each other.

5 is a switching gate for molding the outer and inner synthetic resin layers;
Following the gate 5, a runner 6 for forming an inner synthetic resin layer and a runner 7 for forming an outer synthetic resin layer are installed in the cavity 3, respectively.
It is formed to lead to. Numerals 8, 9 and 10 are slide cores disposed in such a way that they can move in and out of the cavity 3 in conjunction with the movable mold plate.
, 9.10 may be an integral rod body, but in this case, they are formed of a double structure of core bodies 8A, 9A, IOA, cylinder bodies sT3, 9B, and IOB so that they can mutually slide on the shaft. .

The cylindrical body 8B of the slide core 8 aligns with the open end of the runner 6 at a predetermined entry position into the cavity 3.
a is formed through the wall surface of the cylindrical body 8B so that the inner surface side has a smaller diameter than the outer surface side, and the end peripheral surface is a stepped portion 8b that forms a protrusion of the outer surface lining resin layer 26 of the joint 21.
, a stepped portion 8C forming a gap 24 corresponding to the threaded portion 23 of the joint 21, and the tip thereof is connected to the joint body 2.
It is formed to have a slightly protruding length than the length corresponding to the screw 23 of No. 2. The lower half of the top end of the core body 8A in FIG. 1 is cut at 45 degrees in this case to form an inclined surface 8d, and between the inclined surface 8d and the side surface communicating with the runner 8aK of the cylindrical body 8B, A runner 8e for molding the inner synthetic resin layer is formed which penetrates between both parts, and furthermore, from the inclined surface 8d to the upper circumferential surface in FIG. The diameter is narrowed down and a runner 8f is formed through the upper circumferential surface.

Also, on the peripheral surface of the end of the core body 8A, there is a thread 2 of the joint body 22.
Floating inner surface synthetic resin layer 2 on the part corresponding to part 3
In order to form the extension part 5, a step part 8g is formed to form a gap with the cylindrical body 8B. On the other hand, at the end of the core 9A of the slide core 9, an inclined surface 9a similar to that of the core 8A is formed, and a partial runner 9b communicating with the runner 8f is formed at the middle of the end of the core 9A. The upper part of the runner 9b has a hook-shaped core 9A with respect to the partial runner 9b, with the inner side being deeper upward than the end side. The circumferential surface of the core body 8A forms a stepped portion 9C similar to the stepped portion 8g of the core body 8A. Regarding the cylinder 9B, similarly to the steps 8b and 8c on the outer surface of the cylinder 8B, there are steps 9d and 9.
e is formed, and has a configuration symmetrical to the peripheral surface shape of the core 8. Furthermore, the core body 1'O of the slide core 10
End face d of A, each core 8. 9. 10 cavities 3
When the core body enters a predetermined position within the core body, an inclined face 10a is formed with both sides cut from the center so as to coincide with the above-mentioned respective inclined faces 8d and 9a of the cores 8 and 9. 1
The peripheral surface of the end portion of 0A is formed with a stepped portion 10b'ff similar to the stepped portion 8g of the core body 8A. Regarding the cylinder 10B, a step 10 similar to the steps 8b and 8c on the outer surface of the cylinder 8B is formed.
c and 10d are formed, respectively.

In order to line the inner and outer surfaces of the joint body 22 with a synthetic resin layer using a mold having such a structure, the joint body 22 must be placed inside the cavity 3 of the movable mold plate 2, as shown in FIG. If the magnet 4 is set so as to take a predetermined position and is then aligned with the fixed side template, an interlocking mechanism (not shown), for example, an inclined pin provided on the fixed side template and each core 8, 9° Each core 8, 9
゜10 enters the inside from each connection I of the joint body 22,
As shown in Figure 2, at the same time as the mold is closed, each core 8,9゜10
The ends of the joint body 22 are pressed together to form a predetermined space for synthetic resin lining on the inner and outer surfaces of the joint body 22, that is, an inner lining cavity 3A and an outer lining cavity 3Bi. At this time, the magnet 4 supporting the joint body 22 at a predetermined position in the -H cavity 3 is connected to each slide core 8 by a manual mechanism or the like to connect the fixed side mold plate and the cam mechanism as appropriate. 9. Immediately before or after the movable mold plate 10 takes the predetermined position, it is retracted from the supporting position and finally coincides with the wall surface forming the cavity 3 of the movable mold plate 2. Therefore, at this time, the joint body 22 is stably and firmly fixed in the mold 1 by the cores 8, 9, 10, with a predetermined cavity formed therein for the synthetic resin lining.

In this state, when synthetic resin is injected through the switching gate 5, the resin from the inner surface synthetic resin layer forming runner 6 is filled into the inner surface lining cavity 3A of the joint body 22 from the runners 8a, 8e, and 8f. The resin from the outer synthetic resin layer forming runner 7 is immediately filled into the outer lining cavity 3B. After filling, cooling water is passed through cooling holes (not shown) provided in each mold plate to cool the mold 1'f and harden the filled resin. Then mold 1'f: Open 11
In conjunction with the movable side mold plate in the opposite manner to the above-described operation, each slide core 8, 9, 10 moves back together with respect to the joint body 22 and returns to the position shown in FIG. At this time, the resin filled in the runners 6.8c is rotated clockwise in FIG. As the core 9 retreats, the resin in the partial runner 9b is caught by the hook-shaped portion 9f of the core 9 above and moves together, so the filled resin is pulled together and can be easily taken out. . In addition, the joints of the product are each slide core 8. 9. After 10 has retreated, it can be detached from cavity 3 and taken out using magnet 4 or a separately provided protruding mechanism. Furthermore, if the joint body 22 is heated in advance before the resin lining, bondability with the resin will be better.

Figures 3 and 4 are a partially sectional plan view of the main part corresponding to Figure 1 for explaining another resin lining method of the present invention, and Figure 2 is a plan view of the synthetic resin in a state ready for injection. This is a plan view of the main part with a part cut away, but in this case, the inner surface is lined with resin without using the slide core, and the same parts as the mold in Figure 1 are given the same reference numerals. Therefore, its explanation will be omitted. In this case, the movable mold plate 2' of the split mold 1' is provided with only one runner 7, and the cavity of the runner 7 of the joint body 22', which is set to be attracted to the magnet 4, A through hole 22'a communicating with the inner and outer surfaces of the wall portion corresponding to the opening gate 3 is formed in the wall portion corresponding to the opening gate 3.

Therefore, in this case as well, by closing the movable template, each slide core 8, 9. 1
0 is set, cavity 3 for inner and outer resin lining
A and 3B are formed. Therefore, when synthetic resin is injected through the runner 7, the resin is filled into the cavity 3B to form an outer synthetic resin layer, and is also filled into the cavity 3A through the wall through-hole 22'at of the joint body 22'. , forming an inner synthetic resin layer. In this case as well, it is preferable to heat the joint body 22' appropriately in advance. Thereafter, by cooling and opening the mold in the same manner as in the above case, a joint 21' whose inner and outer surfaces are lined with resin will be obtained.

As described above, the present invention sets the joint body in the split mold,
In addition, the manufacturing method involves inserting a slide core into the joint body to form lining cavities on the inner and outer surfaces of the joint body, and then filling each cavity with molten resin.
The inner and outer surfaces of the metal joint main body can be coated reliably and firmly with the full synthetic resin layer, and the thus obtained anticorrosive joint on the inner and outer surfaces is extremely excellent as a joint for underground piping.

[Brief explanation of the drawing]

In order to explain the method of the present invention, Fig. 1 is an example in which the fixed plate of the split mold is omitted and the main body of the joint to be lined is shown set, with a part of the main part mold shown in section 7. FIG. 2 is a partially sectional plan view of the mold shown in FIG. 1 when the mold is closed and the synthetic resin can be injected. FIGS. 3 and 4 are views of another synthetic resin according to the present invention. FIG. 2 is a plan view of each main part, with a part thereof in cross section, corresponding to FIG. 1 and FIG. 2, respectively, for explaining the lining method. 1.1'・・・Split mold, 2,2′・・・・・・
・Movable side template, 3.3A, 3B... Cavity cover 4-... Magnet, 8, 9. 10...
Slide core, 21... Inner and outer anti-corrosion joint, 22
. . . Joint body, 25 . . . Inner surface synthetic resin layer, 26 . . . Outer surface synthetic resin layer. Applicant Mitsubishi Plastics Co., Ltd. and one other person No. 317I Figure 4 ζi, 5++ Procedural amendment form) 1. Display of case 1982 Patent application No. 23729
No. 7 No. 2, Title of the invention Method for manufacturing internal and external anti-corrosion joints 3 Relationship with the amended case Applicant Toyo Kagaku Sangyo Co., Ltd. 300 Kamijo Arai-cho, Kofu City, Yamanashi Prefecture 2, 1 person 4, Agent ◎ 101 5 Date of amendment order] Drafted on March 7, 1982 Sent on March 27, 1982

Claims (1)

[Claims] a step of placing a metal joint body in a split mold consisting of a fixed side mold plate and a movable side mold plate and forming an outer surface lining cavity between the outer surface of the joint body and the split mold; A step of inserting a slide core into the joint body to form an inner lining cavity between the inner surface of the joint body and the slide core, and filling each of the outer and inner cavities with molten resin to form the joint body. 1. A method for producing an inner and outer corrosion-resistant joint, comprising the step of lining the outer and inner surfaces of the joint with a synthetic resin layer.