JP3319508B2 - Corrosion prevention structure, forming method and forming apparatus at end of pipe joint for earthquake resistance - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pipe joint for a cast iron pipe which is buried underground to form a pipe for water supply. The present invention relates to an anticorrosion structure at the end of an earthquake-resistant pipe joint including a cut pipe generated when a cast iron pipe is cut in the middle.

[0002]

2. Description of the Related Art Cast iron pipes are provided with an anticorrosion function entirely by coating the outer surface and inner lining, and are laid underground and surrounded by moisture and other corrosive atmospheres contained in earth and sand that are in contact with the outer peripheral surface of the pipe. Even in contact with running water, it is protected so that corrosion does not easily progress. Therefore, as in the case of ordinary laying work, if the insertion port of another cast iron pipe is inserted into the socket of the cast iron pipe, and it is joined to each other in a water-sealed state with an appropriate water-stopping packing etc., it is almost complete There is no opportunity for water to penetrate into the water, and there is no concern about delivering good quality drinking water to consumers.

[0003] However, the laying of pipes does not always end only with the joining of cast iron pipes of fixed dimensions. In most laying works, it is rare that the last joint point of the section ends at a fixed size of the cast iron pipe, and the cast iron pipe cut halfway to the specified length completes the half-constructed work area Is the normal mode.

[0004] The cut pipe cut on site on the way due to construction work, at least at the cut end, the anticorrosive paint is shaved off,
When the pipeline is laid underground and exposed to a corrosive atmosphere, the exposed cast iron surface becomes a weak point subject to intensive corrosive action. Regardless of how the other surfaces are protected by the anticorrosion function, if there is a weak point to which the metal surface is exposed even in one place, the corrosion protection as a whole is completely lost, corrosion concentrates, and rusting parts are rapidly formed. There is a high concern that the water in the pipe will be polluted in red as a defect that swells like a nodule and that the red water will be delivered to the home.

At present, a method of cutting and adding ductile cast iron pipes to desired dimensions at the site is inevitable at present, and it is natural that a means for ensuring waterproofness of the cut end is required. Most primitively, there is a construction method to re-apply the anticorrosion paint missing at the time of cutting at the cut end of the cut pipe at the site and restore the anticorrosion function. An example of attaching a cover and covering the exposed surface of the cast iron to recover the anticorrosion function has also been practiced.

FIGS. 13 (A) and 13 (B) show a practical example of Japanese Utility Model Laid-Open No. 4-1381.
In the prior art presented in Japanese Patent Publication No. 95, the pipe to be connected is a standard-shaped receptacle as can be seen from FIG. (B), and the tip of the cutting pipe is inserted into this receptacle as an insertion port. Assumes joining. An elastic rubber having a cylindrical body 101 having a diameter slightly smaller than the inner diameter of the target pipe is provided with a plurality of circumferentially continuous annular fins 102 at regular intervals in the axial direction and an annular ridge 103 serving as a stopper at the center. A seal member 104 made of a material, and an inner surface of the seal member 104,
The gist of the present invention is a composite layer in which a metal cylinder 105 having an axially continuous cutout is coaxially and integrally fitted. Due to the elastic deformation of the flexible sealing member 104 and the deformation allowed by the incision cut into the metal cylinder 105 supporting the back, the variation in the inner diameter due to the tolerance of the pipe is absorbed, and the strength of the rubber material is reduced. The weak point is the idea of complementing with the strength of the metal tube fitted behind.

[0007]

On the other hand, as a lesson learned from the Great Hanshin Earthquake last year, the power of the seismic resistant piping system was shown in various ways, and it became an essential requirement for future water pipe laying work. There are various types of earthquake-resistant structures. For example, in the NS type joint of a ductile cast iron pipe shown in FIG. 14 as a slip-on type, a centering rubber 251 and a lock ring 205 are previously inserted into the receiving port 202 and further inserted. The insertion ring 212 is protruded from the opening 201, and at the most retracted position, the lock ring 205 and the insertion ring 212 are locked to prevent further removal,
At the most inserted position, the step 211 corresponding to the insertion port tip 211 and the deepest part of the receiving port 202 is locked to prevent further intrusion, so that in this range, oscillation or vibration such as an earthquake is encountered. Also shows a configuration in which the tube does not come off.

[0008] Among the prior arts exemplified here, in the case of repainting on site, the preparation and application of the coating material are not performed by a coating expert, but the workability and the quality of the painted surface are insignificant. It is not without fear. In addition, since the construction may be a pipe laying construction in a cold district or in a severe winter, it is not uncommon for the factor to spend a long time for drying after painting and to reduce the workability. In addition, there is a possibility that the inspection after construction may be insufficient in the field work, so it is possible to overlook the residual paint, or to perform the local corrosion without completely exhibiting the anticorrosion function provided because the coating is not suitable. There is also concern about rusting.

The application of a dedicated anticorrosive core for a joint at the time of replenishment piping surely improves the low reliability of the manual operation. However, a dedicated anticorrosion core for a joint as shown in FIG.
It is extremely difficult to apply to a cut pipe of a seismic pipe joint as shown in FIG. That is, it is unknown in advance where the cut tube is to be cut, and as shown in FIG. 14, the insertion ring cannot be previously provided around the insertion port at the time of production of the ductile cast iron pipe. Inevitably, a method must be used in which a concave groove is machined and cut near the cut after cutting the dimensions at the laying construction site, and the opening ring is inserted into the groove. For this reason, a non-painted surface also appears on the entire surface of the groove in addition to the cut, and at the same time, in order to guarantee the seismic resistance, a structure in which the tip of the insertion port can relatively move over a certain range in the receptacle as shown in FIG. Must. In order to cover this movable range by applying the anticorrosion core of FIG. 13, a very wide range of length is required as shown in FIG. Practically, shortening of the inner diameter of the pipe over such a long section leads to an essential defect as a pipe, which causes a pressure loss, and is complicated in manufacturing and joining work of the anticorrosion core. There is a high concern that this will be a major burden.

In order to solve the above-mentioned problems, the present invention provides an anti-corrosion structure at the end of a seismic pipe joint which is easy to join a seismic structure using a cut in a field laying work and has excellent workability. With the goal.

[0011]

According to the present invention, the anticorrosion structure at the end of an earthquake-resistant pipe joint according to the present invention is obtained by applying the end anticorrosion rubber 3 to the non-painted surface consisting of the cut 11 of the cut pipe insertion port 1 and the inclined surface 12. The grooved anticorrosion rubber 4 is fitted into the gap between the inner surface 21 of the insertion ring 2 and the fitting groove 13 in which the insertion ring is fitted, and the insertion ring is inserted from the outer peripheral surface of the end anticorrosion rubber 3. 2 is covered with an anti-corrosion cover 5 made of a corrosion-resistant metal plate, and the lower end of the anti-corrosion cover 5 on the insertion ring side and the upper end of the groove anti-corrosion rubber 4 are undetachably engaged. Solved the problem.

As a method of forming the anticorrosion structure, a fitting groove 1 into which an insertion ring 2 is inserted into an insertion port 1 of a cut pipe is provided.
3 and the inclined surface 12 are cut, and the unformed anti-corrosion cover 5 and the grooved anti-corrosion rubber 4 in the form of a cylinder whose only rear end surface 51 is bent at a right angle onto the outer peripheral surface 14 of the insertion opening are deposited.
And the end anticorrosion rubber 3 covering the inclined surface 12 and the unpainted surface of the cut 11 is attached.
The groove anticorrosion rubber 4 is inserted into the gap between the inner surface 21 of the insertion ring 2 and the fitting groove 13 and locked and pressed to support the entire insertion opening and press the outer peripheral surface of the anticorrosion cover 5 having a cylindrical shape. Then, it is plastically deformed into a predetermined shape, and is achieved by a procedure of covering the entire end portion from the insertion ring 2 to the cut 11.

The anticorrosion structure according to the present invention has a cutting surface formed at the site for adjusting the length of a pipe, and a cut surface of an insertion end composed of a cut surface 11 and an inclined surface 12, that is, a non-corrosion coated non-cut surface. The entire surface of the painted surface and the exposed outer peripheral surface of the insertion ring 2 is covered with an anticorrosion cover 5 to cut off contact with the outside to prevent rusting, and to reduce the gap between the insertion ring 2 and the fitting groove 13. Since the groove anticorrosion rubber 4 is fitted and compression-engaged below the rear end face 51 of the anticorrosion cover 5,
While preventing the groove anticorrosion rubber 4 from coming off, it also prevents rust on the side surface of the fitting groove, which is a non-painted surface, while exhibiting a retaining function.

FIGS. 2A and 2B show a method of forming the anticorrosion structure.
Insert ring 2 at end, anti-corrosion rubber 3 at the end,
After each of the groove anticorrosion rubbers 4 is attached, the rear end face 51 of the unformed anticorrosion cover 5 having a right cylindrical shape is pressed and deformed by a special jig in a state where the rear end face 51 is in contact with the inner surface 21 of the opening ring 2.
At this time, the generated bending force P1 plastically deforms the outer peripheral surface of the anticorrosion cover 5. The plastically deformed anticorrosion cover 5 receives the repulsion force P2 of the elastic rubber generated between the end anticorrosion rubber 3 and the tip of the insertion port, and induces the action of more securely inserting the anticorrosion cover to the tip of the insertion port. Solve the problem. Also,
The use of an elastic rubber material for the end portion anticorrosion rubber 3 prevents water from entering from the end surface.

The anticorrosion structure of the present invention is based on the premise of earthquake resistance in particular.
(A) When the joint part is contracted due to crustal deformation as shown in (B), the pull-out forces P1 and P2 act on the pipe, and the engaging part (lateral protrusion 53) at the lower end of the groove anticorrosion rubber is inserted into the insertion ring 2. There is a possibility that the solid portion S in FIG. 8B may be broken by being sandwiched by the lock ring 9 and the lower portion of the rear end face 51 of the anticorrosion cover. Since the surface is compressed and engaged, the water blocking function is not impaired and is maintained normally, so that rust is not generated from the gap of the fitting groove.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a partially longitudinal front view (A) showing an embodiment of the present invention, and an enlarged view (B) of a main part (circumscribed area) in FIG. A lock ring 9, which is evenly urged by a rubber ring 81 and a lock ring centering rubber 91 from the pipe end side, is attached to the socket 8 of one ductile cast iron pipe. A fitting groove 13 is formed in the insertion opening 1, and the insertion opening ring 2 is fitted into this groove, and at the final stage of the movement, the insertion opening ring 2 is formed.
The lock ring 9 collides with the lock ring 9 to serve as a stopper, and there is no change in the basic conditions for forming a typical anti-separation anti-seismic structure.

The anticorrosion structure, which is a feature of the present invention, has an inclined surface 12 (in the figure, a slanted surface) in which the inner peripheral surface of the insertion port is cut obliquely from the cut 11 which is the end face of the insertion port 1 of the cut pipe.
The area where the cross mark is continuous is an unpainted surface newly generated by the cutting pipe preparation), the inclined surface 22 of the insertion ring 2 that maintains a continuous gradient on the inclined surface 12, and the insertion ring 2 having the maximum outer diameter. It is formed by a corrosion-resistant cover 5 made of a corrosion-resistant metal plate that covers the top surface 23 and the inner surface 21 of the insertion ring tightly.

Further, the anticorrosion cover 5 is not directly attached to the outer peripheral surface of the insertion opening or the outer peripheral surface of the insertion ring, but the end anticorrosion rubber 3 and the groove anticorrosion rubber 4 are exposed to the exposed unpainted surface where there is a possibility of corrosion. It has already been described that the interposed member exhibits a strong water-shielding effect and a detachment preventing effect by co-working with its elasticity. If the details of the embodiment are illustrated by each member, FIG. 4 shows a partially longitudinal front view (A), a partial side view (B), and a main part (circular area) in FIG. ) Is an enlarged view (C) and a further enlarged view (D) of FIG. (C), wherein only the rear end portion of the right cylindrical shape is bent inward at a constant width right angle to form a rear end surface 51, Lateral projection 5 having a tapered surface 52 at its lower end
Form 3

FIG. 5 is a partial longitudinal front view (A), a partial side view (B), and an enlarged view (C) of a main part (circular range) in FIG. The molded state is the tip face 54, the slope faces 55, 56, the horizontal faces 57, 58
Is newly classified. The material is preferably stainless steel, copper, or a copper alloy, as is the requirement for a member that normally comes into contact with water, such as corrosion resistance, strength, and formability.

FIG. 6 is a partially longitudinal front view (A), a partial side view (B), and an enlarged view (C) of a main part (circular range) in FIG. End face cut 1
The non-painted surface from 1 to the inclined surface 12 is covered to prevent corrosion. In practice, an appropriate one may be selected from rigid rubber used as a rubber ring for water supply. In terms of shape, the rubber thickness of the inward protruding portion 31 at the tip is determined by the slope surface 32 and the horizontal surface 33.
When the anticorrosion cover 5 is pressed and formed, it is sandwiched between the front end face 54 of the anticorrosion cover and the cutout 11 of the insertion opening, and a sufficient repulsion force of the rubber is generated. It is desirable to fix it.

FIG. 7 is a partial longitudinal front view (A), a partial side view (B), and an enlarged view (C) of a main part (circular range) in FIG. 13 and a main body 41 having a substantially rectangular cross section which inevitably occurs between the inner surface 21 of the insertion ring 2 and a gap which becomes a "water path", and a rear end surface 51 of the anticorrosion cover which is easily engaged with the top surface. An engagement piece 43 having a tapered surface 42 and a tapered surface 44 forming the tip of a laterally projecting portion 45 thinner than the main body 41 project from both ends of the top surface of the main body.

FIG. 8 illustrates the engagement relationship between the groove anticorrosion rubber 4 and the anticorrosion cover 5. The anticorrosion cover 5 indicated by a two-dot chain line in FIG. When it is slid to the left and set at a predetermined position, the tapered surface 52 of the anticorrosion cover 5 and the tapered surface 42 of the grooved anticorrosion rubber 4 are pressed tightly engaged, and the lateral protrusion 45 of the grooved anticorrosion rubber is provided.
Is fixed from above by compressing it from above. The compressed groove anticorrosion rubber 4 is sealed in the gap and cuts off the communication with the outside, so that the restraint fixation and the water-proof and rust-preventive action are simultaneously exhibited.

FIG. 9 is a partial longitudinal sectional front view (A) showing an embodiment of an apparatus used for forming the anticorrosion structure of the present invention.
FIG. 4B is an enlarged view (B) of a main part (circular range) thereof, in which a forming press is applied. Since cut pipes are usually generated at the final stage of construction at the site where the pipeline is laid, measures must also be taken at the construction site to fit an insertion ring into the insertion port of the cut pipe to create an earthquake-resistant structure. . Therefore, it is required that the equipment to be used is easy to handle, easy to transport, and light. In the embodiment shown in this figure, the insertion port support plate 61 for fixing the insertion port 1 of the cut tube fitted with the insertion port ring 2 and the forming section support plate 62 for supporting the hydraulic jack 63 at the center so that the hydraulic jack 63 can be extended and contracted. And are integrated with each other by fastening them together with long bolt nuts 65. The outer peripheral surface 14 of the insertion port 1 is fixed by the insertion port support plate 61, and the hydraulic jack 6 is fixed between the support plates 61 and 62.
The cylinder 3 is extended to plastically deform the anticorrosion cover 5 into a shape following the molding die 64. If the inner diameter of the straight cylindrical anticorrosion cover 5 before deformation is D, the shortest end surface 54 (FIG. One guideline is to narrow down to about 0.8D for the inner diameter of ()). Forming the anticorrosion cover using a forming press provides good finish after forming, and has the advantages of good workability because no work such as welding is required, and that no special techniques are required for construction. Can be As a material of the molding die, a non-ferrous alloy such as a gunmetal is preferable in consideration of a material of the anticorrosion cover.

FIG. 10 shows another embodiment (before molding) of forming an anticorrosion cover. FIG. 10 is a partially longitudinal front view (A) using a spinning machine 7 and an enlarged view (B) of a main part in FIG. ), And FIG. 11 shows the same embodiment after molding. Insert support plate 7 for fixing insert 1 as shown in the figure
1 and a pressing shaft support plate 73 which is screwed with a pressing shaft 72 having a handle 76 at an end thereof, is integrally fastened by a long bolt nut 77 to oppose each other at a distance. Abuts a center of a side surface of a housing 75 in which a motor with a built-in motor (not shown) is built. A movable shaft 78 connected to a motor in the housing 75 rotates a forming plate 79, and inside the forming plate 79, forming rollers 74A and 74
When the handle 76 is turned, the housing 75 is pushed forward by the tip of the pushing shaft 72, and the forming roller 74 is moved forward.
A ... advances while rotating, plastically deforms the anticorrosion cover material of a straight cylindrical shape, and forms it into a predetermined shape. FIG. 11 shows a state where the molding is completed. In the embodiment of this figure, the anticorrosion cover is formed by rotating the processing machine side, but the same result can be obtained by pressing the formed plate while rotating the insertion port side.

FIG. 12 is a diagram showing a construction procedure according to the present invention. In FIG. 1A, after processing the inclined surface 12 fitting groove 13 of the cut tube, the unprocessed anticorrosion cover 5 and the groove anticorrosion rubber 4 are deposited in the insertion opening 1. In FIG. 1B, after the insertion ring 2 is fitted into the fitting groove 13, the groove anticorrosion rubber 4, the anticorrosion cover 5, and the end anticorrosion rubber 3 are set at predetermined positions. In FIG. 4C, the forming press 6 is attached to the insertion opening 1, and the hydraulic jack 63 is operated to press the forming die 64 against the outer peripheral surface of the anticorrosion cover 5. In FIG. 4D, the outer peripheral surface of the anticorrosion cover 5 is pressed and deformed. The forming press 6 is removed to complete the anticorrosion structure.

[0026]

As described above, according to the present invention, when a pipe joint to be joined to a receiving port is made earthquake-resistant by using a cut pipe generated in the on-site laying work of the pipeline, only the unpainted portion inevitably generated. Since the structure is covered with the anticorrosion cover, it can be constructed as usual after the anticorrosion cover is attached. Unlike the prior art (FIG. 13), since no member is inserted into the inner peripheral surface of the insertion port, the problem of pressure loss does not occur without reducing the inner diameter of the pipe. Even if the joint part expands or contracts due to ground deformation after pipe joining, the anticorrosion cover moves together with the insertion ring, so that the anticorrosion function is maintained without any influence.

Particularly, the feature of the present invention is that it has a stronger function of preventing detachment since it has a stronger binding force than the conventional anticorrosion cover and the like, and has an anticorrosion effect even when an external force such as vibration, vibration or impact is applied to the pipeline. The guaranteed benefits are great. In addition, cut pipes often occur at the final stage of pipe laying work, but the procedure for installing the anticorrosion structure of the present invention is easy and easy, and the quality depends on individual differences without assuming special skill of workers. There is no variation. An apparatus such as a molding press requires only a simple and portable structure, has a small maintenance burden, has good workmanship, and has a far superior effect of forming a joint having a robust appearance.

[Brief description of the drawings]

FIG. 1 is a partial longitudinal sectional front view (A) of an embodiment of the present invention and an enlarged view (B) of a main part (circular part) of the same figure.

FIG. 2 is a partial vertical sectional front view showing before (A) and after (B) molding of the anticorrosion cover.

FIG. 3 is a partial longitudinal front view (A) showing the inside of the pipe joint in which the pipe has relatively moved due to crustal deformation, and an enlarged view (B) of a main part (circular part) of the same figure.

FIG. 4 is a partial longitudinal front view of the anticorrosion cover before molding (A),
It is the enlarged view (C) of the principal part (deformation part) of the partial side view (B) and figure (A), and the enlarged view (D) which further expanded a part further.

FIG. 5 is a partial longitudinal front view of the anticorrosion cover after molding (A),
It is a partial side view (B) and the enlarged view (C) of the principal part (deformation part) of FIG.

FIG. 6 is a partial longitudinal sectional front view (A), a partial side view (B), and an enlarged view (C) of a main part (deformed part) of FIG.

FIG. 7 is a partial longitudinal sectional front view (A), a partial side view (B), and an enlarged view (C) of a main part (deformed part) of FIG.

FIG. 8 is a partial cross-sectional view showing an engagement state between the anticorrosion cover and the groove anticorrosion rubber.

FIG. 9 is a partial longitudinal sectional front view of a molding press (A), an enlarged view (B) of a main part (circular part) of the same figure, and an enlarged view (C) of a main part (circular part) of FIG. .

FIG. 10 is a partial longitudinal front view (A) of a spinning machine (before forming an anticorrosion cover) and an enlarged view (B) of a main part (circular portion) of the same figure.

FIG. 11 is a partial vertical front view (A) of the same apparatus after the formation of the anticorrosion cover, and an enlarged view (B) of a main part (circular part) of the same figure.

12 (A) to 12 (E) show a construction procedure of the present invention in a partially longitudinal front view.

FIG. 13 is a vertical sectional front view (A) of a conventional technique (corrosion protection structure for a cut pipe) and a partial vertical sectional front view (B) of an embodiment.

FIG. 14 is a partial longitudinal sectional front view showing a conventional technique (seismic pipe joint).

FIG. 15 is a partial longitudinal front view showing a problem when a conventional anticorrosion structure is applied to an earthquake-resistant structure.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Insertion opening 2 Insertion ring 3 End anticorrosion rubber 4 Groove anticorrosion rubber 5 Anticorrosion cover 6 Molding press 7 Spinning machine 8 Reception opening 9 Lock ring 11 Cut end 12 Inclined surface 13 Fitting groove 14 Outer surface 21 Inner surface 31 Inward Projection 41 Body 42 Tapered surface 43 Engagement piece 44 Tapered surface 51 Rear end surface 52 Tapered surface 53 Lateral projection 54 Tip surface 61 Insert support plate 62 Mold support plate 63 Hydraulic jack 64 Mold 71 Insert support plate 72 Pressing shaft 73 Pressing shaft support plate 74 Forming roller 75 Housing

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-54-34124 (JP, A) JP-A-11-230483 (JP, A) JP-A-7-112485 (JP, A) 22198 (JP, U) Fully open sho 61-99794 (JP, U) Fully open sho 62-15681 (JP, U) Fully open flat 3-86293 (JP, U) Fully open sho 60-169488 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) F16L 21/00-21/08 F16L 58/18 F16L 57/00

Claims (5)

(57) [Claims] In an earthquake-resistant pipe joint including a cut pipe, an end-corrosion-resistant rubber 3 is entirely attached to a non-painted surface formed by a cut 11 and an inclined surface 12 of a cut pipe insertion port 1 to cover the cut pipe. The groove anticorrosion rubber 4 is inserted into the gap between the inner surface 21 of the ring 2 and the fitting groove 13 into which the insertion ring is fitted, and the corrosion resistant metal extends from the outer peripheral surface of the end anticorrosion rubber 3 to the exposed surface of the insertion ring 2. An end of the anti-seismic pipe joint, wherein a lower end of the anti-corrosion cover 5 on the insertion ring side and an upper end of the groove anti-corrosion rubber 4 are irremovably engaged with each other. Anti-corrosion structure. 2. The engagement member according to claim 1, wherein the anticorrosion rubber groove is formed as an annular body having a substantially L-shaped cross section, and a top surface of a main body inserted into the gap has a tapered surface protruding outward. At both ends, a mating piece 43 and a lateral protrusion 45 projecting laterally and terminating at a tapered surface 44 are provided, while the lower end of a rear end surface 51 of the anticorrosion cover 5 bent at a right angle is formed into a tapered surface 52.
And the tapered surface 52 of the anticorrosion cover 5 and the horizontal projection 53 compress the tapered surface 42 of the grooved anticorrosion rubber 4 and the horizontal projection 45 so that they cannot be separated. An anticorrosion structure at the end of a pipe joint for earthquake resistance. 3. A method for forming an anticorrosion structure at an end of an earthquake-resistant pipe joint including a cut pipe, wherein a fitting groove 13 and an inclined surface 12 for inserting an insertion ring 2 into an insertion port 1 of the cut pipe are cut and processed. The unformed anti-corrosion cover 5 and the grooved anti-corrosion rubber 4 in the form of a cylinder whose only the rear end surface 51 is bent at a right angle are deposited on the outer peripheral surface 14 of the insertion port, and the insertion ring 2 is fitted into the fitting groove 13 and inclined. The end anticorrosion rubber 3 covering the non-painted surface of the face 12 and the cut 11 is attached, and the groove anticorrosion rubber 4 is fitted into the gap between the inner side surface 21 of the insertion ring 2 and the fitting groove 13 and locked and crimped. To support the entire insertion opening and to press the outer peripheral surface of the unformed anticorrosion cover 5 of a right cylindrical shape to plastically deform into a predetermined shape, thereby covering the entire end of the insertion opening from the insertion ring 2 to the cut 11. For forming anti-corrosion structure at the end of seismic fittings Law. 4. An insertion port support plate 61 for fixing an insertion port 1 of a cut tube fitted with an insertion port ring 2, a hydraulic jack 63.
A straight cylindrical unformed anticorrosion anti-corrosion member, which is fastened at a distance to a molded portion support plate 62 which supports the center of the opening ring 2 at a distance, and one end of which is attached to the outer peripheral surface of the opening ring 2 between the two support plates 61, 62. A molding die 64 for plastically deforming the outer peripheral surface of the cover 5 into a predetermined insertion end shape is formed by a molding press 6 connected to the hydraulic jack 63. Molding equipment. 5. An insertion port support plate 71 for fixing an insertion port 1 of a cut tube fitted with an insertion port ring 2 in place of the forming press 6, and a pressing shaft 72 screwed at the center. The pressing shaft support plate 73 is fastened at a distance and both support plates 7
A plurality of stages are connected in series so as to press the outer peripheral surface of the unformed anti-corrosion cover 5 of a straight cylindrical shape having one end attached to the outer peripheral surface of the insertion ring 2 between the first and the third 73 to form a predetermined insertion end shape. Forming plate 79 in which forming rollers 74A, 74B,.
Characterized by a spinning machine 7 in which a housing 75 for rotating the forming plate 79 is in contact with the pressing shaft 72 so as to be able to move forward and backward so as to face the insertion port 1. Equipment used for