JPH0557098B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an apparatus for manufacturing a lined curved pipe, and more specifically, a lined elbow (hereinafter referred to as
This relates to manufacturing equipment for LP joints.

Note that the elbow here includes 90° long elbow, 90° straight pipe with short elbow, 45° elbow, etc.

[Conventional technology and its problems]

Generally, synthetic resin pipes have poor heat resistance, pressure resistance, and impact resistance, so to compensate for these drawbacks, they are constructed into composite pipes using steel pipes as reinforcement materials.

The manufacturing method for such composite pipes involves sufficiently surface-treating the inner surface of the steel pipe, applying adhesive to the inner surface of the steel pipe and the outer surface of the inner hard vinyl chloride pipe, and after drying, applying adhesive to the inner hard vinyl chloride inner pipe. While degassing between the steel pipe and inner hard vinyl chloride pipe, heating and pressure lining is performed, and after cooling, the flange is turned back to form a finished product.

On the other hand, the principle of manufacturing methods for LP joints is the same as that for composite pipes, but various concrete proposals have been made (for example, Japanese Patent Publication No. 15462/1983, Miyazaki et al.; Application with,
(See page 600). However, currently being carried out,
The process of manufacturing a typical LP joint by blow lining is shown in FIG. In other words, in the process shown in Figure 6, if we explain the flanged elbow made of steel pipe, it is called "pickling".
The inner surface is treated, and an adhesive is applied to the inner surface. Next, similar to the method for manufacturing the composite pipe,
"dry. On the other hand, for hard vinyl chloride pipes that have thermal expansion properties, the original pipe is "cut" and then "bended". Then, "apply adhesive" to its outer surface and "insert" it into the elbow at room temperature.

Next, these elbows, along with the bent pipes of hard PVC pipes inside them, are subjected to "pre-treatment".
and set it in the housing. This is done by fastening the elbow flange with multiple bolts. Next, the flange of the oil pipe for circulating the heated oil is further set to match the flange of the elbow. Thereafter, oil is circulated inside the hard vinyl chloride pipe to heat the hard vinyl chloride pipe, and the outer periphery of the elbow is also heated with a burner to melt the adhesive. Next, the stop of the oil pipe provided on the outlet side of one flange is closed, and the oil in the hard vinyl chloride pipe is pressurized. Therefore, the material for the LP joint is completed by applying so-called oil blowing and ``hydraulic lining.'' Next, as a "post-processing", the multiple bolts screwed to the flange of this elbow are removed from the housing, and the inside hard vinyl chloride pipe is "flipped".
Complete the LP fitting.

By the way, despite the recent demand for LP joints, the manufacturing method of LP joints using oil blowing is extremely time-consuming due to the bending process of hard PVC pipes and the drying process of adhesive. Poor productivity (e.g. 7 pieces/day)
Product costs are rising.

[Means for solving problems]

Therefore, the present invention focuses on solving the problems of the conventional method of manufacturing LP joints using oil blowing, and through trial and error, the following invention was completed and is thus provided herein. In other words, the gist is that in a manufacturing device for a lined curved pipe in which a synthetic resin pipe is fitted into a metal curved pipe via an adhesive and integrated by blow molding, the straight pipe is heated and softened. A long arm is formed by fitting a synthetic resin pipe into a bent pipe, and the arm has a plate-like cross-section with the long side in the direction of the rotational axis, and an arc-like shape with the rotational axis as the center. The apparatus for manufacturing a lined curved pipe is characterized in that the rotation axis of the arm is located at the center point of the circular arc of the metal curved pipe.

〔Example〕

The structure of the present invention will be explained in detail with reference to its working examples.

FIG. 1 is a plan view of an embodiment of the present invention, showing a state in which the lower molds 4 and 17 are open, and FIG. 2 is a plan view of an embodiment of the present invention.
The arrow side view and FIG. 3 show a sectional view taken along line B-B in FIG. 2.

In these figures, the outline of the device is a steel pipe flanged elbow 1 (for example, nominal diameter 80 to 250 mmφ) with adhesive applied to the inner surface and outer surface of the flange 1a, and a steel pipe flanged elbow 1 (for example, nominal diameter 80 to 250 mmφ) that is heated and softened to a predetermined shape. A straight hard vinyl chloride pipe (hereinafter referred to as vinyl pipe) 2 cut to length and coated with adhesive on its outer surface, and a first pipe for bending the vinyl pipe 2 and pushing it into the elbow 1. This is a device that manufactures LP joints by air blowing.

To explain this in detail, 3 is the lower first clamp,
4 is a lower mold that is slidably attached to the side surface of the lower first clamp 3; 5 is a first housing for placing the lower first clamp 3 and the lower mold 4;
Reference numeral 6 denotes a vertical axis provided under the first housing 5, and is located approximately at the center point of the arc of the elbow 1. 7
A first arm pivots approximately at the center of the vertical axis 6, and is formed into a long plate-like arc with the vertical axis 6 as the center in plan view. The base 8 of the first arm 7 is formed to have an elliptical cross section, and an elliptical flange 9 and a short axis 10 are connected to the base 8.

11 is a second arm, the tip of which is connected to the short axis 10 of the first arm 7 via a stand 12, and the base of the second arm 11 is connected to the vertical axis 6.
is fixed to.

An auxiliary stand 12a is attached to the stand 12, and these stands 12 and the auxiliary stand 12a
is erected on the substrate 13. The substrate 13 is fixed to the tip of the second arm 11.

The lower mold 4 is divided into two halves 4a and 4b, and two cylinders 14 and 15 are used to form the first mold.
They reciprocate on the housing 5 using the rails 5a and 5b as guides and along the side surface of the lower first clamp 4 to open and close each other.

Further, the second lower clamp 16 and the lower mold 17 shown in the first figure have the same structure as the first lower clamp 3 and the lower mold 4, and these 16,
17 is placed on the first housing 5.

The lower mold 17 is divided into two halves 17a and 17b, and the first
They reciprocate on the housing 5 using the rails 5a, 5a as guides and along the side surface of the lower second clamp 16 to open and close each other. Note that the operations of the cylinders 18 and 19 are linked to the operations of the cylinders 14 and 15.

An upper mold 20 that has the same structure as the first lower clamp 3, the closed lower mold 4, the second lower clamp 16, and the closed lower mold 17, and is integrated with the upper mold 20.
is installed on the first housing 5, and the columns 24, 2
It is designed to be raised and lowered using guides 5 and 26.

A plug body 21 having the same structure as the base portion 8, flange 9, and short shaft 10 of the first arm 7 is provided on the lower mold 17 side, and an air passage 22 is bored in this plug body 21. An air hose 23 is connected.

In addition, 27 is a pushing cylinder for pushing the vinyl pipe 2 into the first arm 7, and 28 is a drive device composed of an air blower or the like, which causes the vertical shaft 6 to reciprocate. Reference numeral 29 is a base frame, and 30 is a second housing, which is fixed onto the base frame 30 and the first housing 5 is assembled on the upper side thereof. 31
3 indicates a frame for suspending the drive device 28;
2 and 33 are bulging notches for bulging and attaching the vinyl pipe 2 to the flange 1a of the elbow 1;
34 is a notch into which the short shaft 10 is fitted, and 35 is a notch into which the base 8 is fitted.

The operation of this device is as follows. That is, the adhesive is applied to the inner surface of the elbow 1 and the outer surface of the flange 1a and heated. This is suspended and placed on the lower first and second clamps 3 and 16 using a chain block or the like. At this time, the lower molds 4 and 17 are opened, and the first arm 7 is retracted to the position shown in the first figure.

Therefore, the heated and softened vinyl tube 2 is fitted onto the first arm 7, which is heated if necessary, using a pushing cylinder 27, and one end thereof is pushed to the base 8 to form a bent tube. At this time, the other end of the vinyl tube 2 slightly protrudes from the tip of the first arm 7. Next, when the driving device 28 is driven and the vertical shaft 6 is rotated, the first arm 7 is rotated through 180 degrees via the second arm 11, and the vinyl tube 2 is pushed into the elbow 1. At that time, the base 8, flange 9 and short shaft 10 of the first arm are positioned between the open halves 4a, 4b of the lower mold 4.

On the other hand, on the side of the lower mold 17, the stopper 21 is pushed into the protruding tip of the vinyl tube 2 using an appropriate cylinder (not shown).

Therefore, the cylinders 14, 15, 18, and 19 are operated, the lower molds 4 and 17 are closed, and the base 8 of the first arm 7, the flange 9, etc., and the stopper 21 are clamped. Both ends of the vinyl tube 2 fitted onto the base 8 are held in the grooves of the elliptical notches 35 of 7. Next, the upper mold 20 (upper mold,
(first and second clamps) are lowered and the mold is clamped like a normal air blow mold. Therefore, setting of elbow 1 is easy.

Therefore, pressurized air is introduced into the air hose 23 to inflate the vinyl pipe 2 housed therein like a normal air blower, so that it is brought into close contact with the inner surface of the elbow 1 and also with the outer surface of the flange 1a.

After that, the upper mold 20 is raised and the elbow 1 is cooled with water, and then the elbow 1 with the vinyl pipe 2 integrated therein is taken out from the lower molds 4 and 17 (see Fig. 4), and the vinyl pipe 2 is protruded. Cut the end along flange 1a to complete the LP joint as shown in Figure 5.

Although this embodiment has been described using a flanged elbow made of a steel pipe, the present invention is not limited to this, and may be a bend made of a steel pipe, and both are collectively referred to as a curved pipe in this specification.

That is, it also includes the case of manufacturing a straight pipe 1' with a 90° short elbow as shown in FIG. 7, for example. To explain Figure 7, a straight pipe with a 90° short elbow (for example, nominal diameter 350 mm, straight pipe length
1000mm) 1' to the lower first and second clamps 3,
16, the first arm 7 is inserted into the straight pipe 1' with a 90° short elbow from the curved side, and the lower mold 4 is closed.

Therefore, the heated and softened straight vinyl pipe 2
' into the piston 36. Next, by reciprocating the reciprocating plate 37 on which the pushing piston 36 is mounted and fixed, the vinyl pipe 2' can be pushed into the straight pipe 1' with a 90° short elbow. Here, since the vinyl pipe 2' is longer than the pushing piston 36, it is pushed into the first arm 7, which is already on standby, by that length, and the bend portion can be formed.
Then, only the push piston 36 is retracted.
Thereafter, a straight pipe 1' with a 90° short elbow is completed using the same method as for manufacturing the LP joint. In addition,
If the lengths of the straight pipes 1' with 90° short elbows are different, adjust the adjustment table 38 on the rail 39.

〔Effect of the invention〕

According to the present invention, when a heated and softened synthetic resin tube is inserted into an arc-shaped arm, a so-called bent tube is formed, so the process of separately processing the bent tube can be omitted, and moreover, Even if adhesive is applied to the inner periphery and/or the outer periphery of the synthetic resin pipe, the synthetic resin pipe is formed with an elliptical cross section and will not fit into the curved metal pipe, so the inner periphery and the outer periphery will not fit together. The contact area is reduced, making it convenient for blow molding. Moreover, the heating step for melting the adhesive can be omitted, and the productivity of the lined curved pipe can be further improved.

[Brief explanation of drawings]

Fig. 1 is a plan view of an embodiment of the present invention, Fig. 2 is a side view taken in the direction of arrow A in Fig. 1, Fig. 3 is a cross-sectional view taken from B to B in Fig. 2, and Fig. 4 is an air lining. 5 is a perspective view of the appearance of the finished product, FIG. 6 is a process diagram of a conventional example, and FIG. 7 is a plan view of another embodiment of the present invention. 1... Elbow with flange, 2... Hard vinyl chloride pipe, 6... Vertical shaft, 7... First arm, 8... Base, 9... Flange, 21... Plug body, 23... Air hose .

Claims (1)

[Scope of Claims] 1. In an apparatus for manufacturing a lining curved pipe in which a synthetic resin pipe is fitted into a metal curved pipe via an adhesive and integrated by blow molding, the synthetic resin is heated and softened in a straight pipe state. A long arm is formed into a bent pipe by fitting the manufactured pipe outward, and the arm is configured to have a plate-like cross section with the long side in the direction of the rotational axis and an arc shape centered on the rotational axis. ,
A manufacturing apparatus for a lined curved pipe, characterized in that the rotational axis of the arm is located approximately at the center point of the arc of the metal curved pipe.