JP3093002B2 - Pipe fitting manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing pipe joints having different diameters for connecting pipes having different diameters.

[0002]

2. Description of the Related Art Conventionally, when manufacturing a pipe joint of different diameters using a plate-like body, first, a thermoplastic resin plate in which one end and the other end are formed by developing a cylindrical body having a different diameter is softened by heating. Then, the thermoplastic resin plate is wound around a mold in a heated and softened state to form a cylindrical body. Then, resin welding was performed along the seam in a state where the winding start end face and the winding end end face of the cylindrical body were butted together.

[0003]

However, in such a conventional method of manufacturing a pipe joint, a high-level technique is required as a means for bonding the winding start end face and the winding end end face of the tubular body. Uses resin welding. Therefore, unless a skilled person performs the resin welding work, due to variations in the pressure of the welding rod and the intensity of hot air that melts the welding rod,
The bonding strength is not stable.

[0004] Further, since a welding rod is usually added with a plasticizer in order to enhance the meltability, the welded bonding portion has a lower strength than the base metal. Therefore, it is difficult to perform secondary processing on the bonded portion after welding.

An object of the present invention is to provide a method of manufacturing a pipe joint that can manufacture a pipe joint without requiring advanced techniques such as resin welding, focusing on the above problems.

[0006]

In order to achieve the above object, a method for manufacturing a pipe joint according to the present invention comprises heating and softening a thermoplastic resin plate having a cylindrical body having one end and the other end developed with different diameters. And
The thermoplastic resin plate is wrapped around a mold in a heated and softened state to form a cylindrical body having one end and the other end having different diameters, and is applied to the inner peripheral surface of the joint between the winding start end surface and the winding end end surface. A method was adopted in which the both end faces were heated and melted in a state where the plate was applied, and the end face of the winding start and the end face of the winding were melt-bonded.

[0007]

In the method for manufacturing a pipe joint according to the present invention, the end surfaces are heated and melted while the abutment plate is applied to the inner peripheral surface of the joint between the winding end surface and the winding end surface of the tubular body. It is possible to prevent beads from being formed inside the cylindrical body during melting, and as a result, it is possible to manufacture a pipe joint having a smooth inner surface.

Further, in the method of manufacturing a pipe joint according to the present invention, as a means for bonding the winding start end face and the winding end end face of the tubular body, welding is employed in which both end faces are heated and melted and then joined. The strength at the location is equal to the base metal strength.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A method for manufacturing a pipe joint according to an embodiment of the present invention will be described below in detail with reference to FIGS.

First, as shown in FIG. 1, a thermoplastic resin plate 1 in which one end and the other end are formed by developing cylindrical bodies having different diameters is heated and softened. For heating, high-temperature oil, hot air, a silicon rubber heater, or the like can be employed.

Next, as shown in FIG. 2, the thermoplastic resin plate 1a is wound around a mold 2 in a heated and softened state to form a cylindrical body 1b having one end and the other end having different diameters.

When the cylindrical body 1b is solidified, as shown in FIGS. 3 and 4, the holder 4 connected to the hydraulic cylinder 3
The winding start end and the winding end end of the tubular body 1b are respectively attached to the cylindrical body 1b so that the joint between the winding start end face and the winding end end face of the tubular body 1b can be opened and closed. Then, by driving each hydraulic cylinder 3 to the contraction side, the joint between the winding start end face and the winding end face of the cylindrical body 1b is opened, and a hot plate 51 of the heater 5 is attached therebetween, and the hot plate 51
Is applied to the inner peripheral surface of the joint between the winding start end face and the winding end face.

Next, by driving each hydraulic cylinder 3 to the contraction side, the winding start end face and the winding end face of the tubular body 1b are pressed against the hot plate 51, and a predetermined temperature (the tubular body is made of vinyl chloride resin). In this case, the mixture is heated and melted at 220 to 250 ° C.). The temperature of the hot plate 51 is adjusted by the controller 53 of the heater 5.

After heating and melting for a predetermined time, each hydraulic cylinder 3 is driven to the contraction side to open the joint between the winding start end face and the winding end face of the cylindrical body 1b, and the heater 5 is removed. In this manner, the winding start end face and the winding end end face of the tubular body 1b are joined and bonded in a heat-softened state.

Finally, as shown in FIG. 6A, the receiving ports 11 and 12 are formed at both ends of the cylindrical body 1b by using a large diameter die, or As shown in FIG. 6 (b), the spigots 13 and 14 are formed at both ends of the cylindrical body 1b using a reduced diameter die to complete the pipe joint.

Next, the operation of this embodiment will be described.

In the method of manufacturing a pipe joint according to the present embodiment, both end surfaces are heated and melted in a state where the contact plate 52 is applied to the inner peripheral surface of the joint between the winding start end surface and the winding end surface of the tubular body 1b. As shown in FIG. 4, it is possible to prevent beads from being formed inside the cylindrical body 1b during the heating and melting, and as a result, it is possible to manufacture a pipe joint having a smooth inner surface.

In the method of manufacturing a pipe joint according to the present embodiment,
As a means for bonding the winding start end face and the winding end end face of the tubular body 1b, welding in which both end faces are joined in a heated and melted state is adopted, so that the strength of the bonded portion is equal to the base material strength. Therefore, the receptacles 11 and 12 or the outlets 13 and 14 can be formed by secondary processing after the bonding without a troublesome operation such as forming a separate cylindrical body and bonding the cylindrical body 1b to the end of the cylindrical body 1b. .

FIG. 7 (a) is a side view showing a modified example of the pipe joint having the sockets formed at both ends, and FIG. 7 (b) is a modified example of the pipe joint having the spigots formed at both ends. In these pipe joints, the center of one receiving port 11a or outlet 13a and the other receiving port 12a or outlet 14a are shifted from each other. The method of manufacturing this pipe joint is the same as that of the above embodiment except that the shape of the thermoplastic resin plate is different, and the other methods are the same.

Although the embodiment of the present invention has been described in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and there are changes in the design without departing from the gist of the present invention. Are also included in the present invention. For example, in the embodiment, in the secondary processing, a pipe joint having receiving ports formed at both ends,
Although the pipe joint having the spigot formed at both ends is shown, in the secondary processing, a spigot may be formed at one end and a spigot may be formed at the other end. Further, in the embodiment, when the winding start end surface and the winding end end surface of the cylindrical body are heated and melted, the contact plate attached to the hot plate of the heater is applied to the inner peripheral surface of the joint of the end surfaces. The plate may be used separately from the heater. Further, the opening and closing of the joint between the winding start end surface and the winding end surface of the cylindrical body is not limited to automatic operation, and may be performed manually.

[0021]

As described above, the method for manufacturing a pipe joint according to the present invention does not require advanced techniques such as resin welding, so that a pipe joint having a stable strength can be used by non-experts. Can be manufactured.

Further, in the method for manufacturing a pipe joint according to the present invention, as a means for bonding the winding start end face and the winding end end face of the tubular body, welding is performed in which both end faces are heated and melted and then joined. Therefore, the strength of the bonding portion becomes equal to the strength of the base material, and an effect that secondary processing after bonding is possible is obtained.

[Brief description of the drawings]

FIG. 1 is a plan view showing a thermoplastic resin plate.

FIG. 2 is a perspective view showing a state where the thermoplastic resin plate is wound around a mold.

FIG. 3 is a perspective view showing a state in which a heater is attached to a tubular body formed from the thermoplastic resin plate.

FIG. 4 is a front view showing a state where a winding start end face and a winding end end face of the tubular body are heated and melted by a heater.

FIG. 5 is a perspective view showing a cylindrical body having both end surfaces bonded thereto.

FIG. 6 (a) is a side view showing a pipe joint completed by forming receiving ports at both ends of the tubular body. (B) is a side view showing the completed pipe joint by forming a spigot at both ends of the tubular body.

FIG. 7A is a side view showing a modified example of a pipe joint in which receiving ports are formed at both ends. (B) is a side view showing a modification of the pipe joint in which the spigot is formed at both ends.

[Explanation of symbols]

 1a Thermoplastic resin plate 1b Cylindrical body 2 type 5 Heater 51 Hot plate 52 Backing plate

Claims (1)

(57) [Claims] 1. A thermoplastic resin plate having a tubular body having one end and the other end having different diameters is heated and softened, and the thermoplastic resin plate is wound around a mold in a heated and softened state, so that one end and the other end are different. A cylindrical body having a diameter is formed, and the both end faces are heated and melted in a state where a contact plate is applied to an inner peripheral surface of a joint between a winding start end face and a winding end face of the tubular body, and the winding start end face and the winding A method for manufacturing a pipe joint, wherein the end joint is melt-bonded.