JPS59175691A - Method of joining pipe and flange - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of joining a flanged pipe to a flange, which is used when joining pipes together with flanges in piping equipment.

In recent years, with the development of welding technology, welded connections are increasingly used to connect pipe systems in piping equipment, and flange connections are being used only in limited fields such as connections with valve bodies. In the flange industry, reducing manufacturing costs has become a major technical challenge in order to cope with this drastic decrease in demand.

Conventionally, as a means of joining a pipe and a flange, the method shown in Fig. 1(a) (
A welding method as shown in b) and a screw joining method as shown in Fig. 2 are used.
In view of the above, we investigated the workability (stickiness) of conventional joining means and came to the following conclusions.

That is, when joining by welding, a skilled welding worker is required, and grooves (3) are cut in the welded part of the pipe (1) or flange (2) as shown in Figure 1 (a). ,
Alternatively, as shown in Fig. 1(b), one step (such as the one required after welding)
4), and in the case of threaded joints, not only do threads need to be cut on both the pipe (1) and the flange (2), but both (1) and (2) must be ground. It was discovered that it required a large amount of man-hours, such as having to conclude multiple contracts.

The present invention employs a press-fitting method in place of conventional welding or threaded joints to reduce the cost of flange connection of such pipe systems, and the present invention aims to reduce the cost of flange connection of such pipe systems. Any joining means that undergoes plastic deformation due to the action of mechanical force, such as a protrusion, is provided, the pipe to be joined is press-fitted into the pipe insertion hole, and the pipe and flange are tightly joined by the plastic deformation of the joining means. This is a characteristic feature.

Next, embodiments of the present invention will be described based on the accompanying drawings.

FIG. 3 shows a first example of implementation, in which a plurality of protrusions having the required width and height are formed on the inner surface of the pipe insertion hole (5) made in the flange (2) as a means of joining the pipe and the flange. (8) are arranged in parallel to each other. In this case, the cross-sectional shape of the protrusion (6) is
The cross-sectional shape is not limited to the triangle shown in FIG. 3, but can be formed into any desired cross-sectional shape, such as a trapezoidal cross-section or a hemispherical cross-section.

The above embodiment is an example in which a plurality of protrusions (6) having the required width and height are provided circumferentially in parallel as a means for joining the pipe and the flange, but the gist of the present invention lies in this. However, as shown in FIG. 4, the protrusion (6
) can also be formed into a spiral strip.

In addition, as a means for joining the pipe and the flange, instead of the protrusion (6) as in the above two embodiments, as shown in FIG. It is also possible to protrude almost uniformly.

That is, whether to select the protrusion (6) or the protrusion (7) and the shape of the protrusion (6) or the protrusion (7) can be determined as appropriate by design.

The three embodiments described above are examples in which a protrusion (6) or a protrusion (7) is formed on the inner surface of the tube insertion hole (5) as a means for joining the tube and the flange. In addition to the structure, as shown in FIG. 6, the required protrusion (8) can also be formed by subjecting the outer circumferential surface of the tip of the tube (1) to a necessary machining process such as a Laurent process.

When joining the pipe (1) and flange (2) formed as described above, as shown in FIG.
1 (9) in the flange (2) (
5) Tightly press fit the tip of the tube (1) into the tube.

The above four embodiments are examples in which no means for improving airtightness was provided between the pipe (1) and the flange (2), but as shown in FIG. A locking step (10) is provided inwardly protruding at the end of the tube insertion hole (5) from which the strip (5) or protrusion (6) is provided, and the locking step (10) and the tube insertion hole (5) are connected to each other. The tube insertion hole (
A gasket 1-(II) formed thinner than the thickness of 5) is installed inside the pipe (1-(II)), and the pipe (
1) can be press-fitted to join the pipe (1) and flange (2) and also to improve airtightness between them.

Since the present invention joins the pipe and flange by press-fitting using a press machine, it does not require skilled workers unlike conventional welding methods, and the process of forming a bevel on the pipe before joining is not required. In addition, the joining method of the present invention can omit the process of cutting out parts of the pipe or the excess after joining.In addition, the joining method of the present invention only needs to form a protrusion or protrusion on either the pipe or the flange. As such, there is no need to perform machining on both the pipe and the flange, and machining is easier than thread cutting. In addition, the pipe and flange can be joined quickly using a press machine, which is more productive than welding or screwing.

In summary, the joining method of the present invention has much better workability than conventional welding methods and screw methods, and can significantly reduce the cost of joining pipes and flanges.

The present invention utilizes the tube insertion hole of the flange or the plastic deformation of the protrusions or protrusions provided on the outer circumferential surface of the tube to join the tube and the two flanges, so that the joint between the two is tight, which is different from the conventional method. Similar to the welding method and screw method, there is no risk of it falling off during use.

[Brief explanation of drawings]

Figure 1 is a cross-sectional view showing a welded joint between a pipe and a flange, Figure 2 is a cross-sectional view showing a threaded joint between a pipe and a flange, and Figure 3 is a cross-sectional view showing a threaded joint between a pipe and a flange. FIG. 4 is a cross-sectional view of a flange showing an example in which a spiral protrusion is provided in the tube insertion hole, and FIG. 5 is a sectional view in which a protrusion is provided in the tube insertion hole. 6 is a front view of a tube showing an embodiment in which projections are provided on the outer peripheral surface of the tube; FIG. 7 is a partial sectional view showing a means for press-fitting the tube and flange; FIG. 8 is a sectional view of the flange shown in FIG. FIG. 2 is a sectional view of a flange showing an embodiment in which a locking step is formed at the end of a tube insertion hole.

Claims (1)

[Claims] ■. When joining a pipe and a flange, a joining means that causes plastic deformation by the action of mechanical force is provided on the inner surface of the pipe insertion hole formed in the flange and/or on the outer peripheral surface of the tip of the pipe;
A method for joining a pipe and a flange, the method comprising: press-fitting the tip of the pipe into the pipe insertion hole of the flange, causing plastic deformation in the joining means by the pressure force of the pipe, and joining the pipe and the flange. 2. The pipe and flange according to claim 1, characterized in that a plurality of parallel protrusions are provided around the inner surface of the pipe insertion hole as a joining means that causes plastic deformation by the action of mechanical force. joining method. 3. A method for joining a pipe and a flange according to claim 1, characterized in that a protrusion is spirally provided around the pipe insertion hole or the inner surface as a joining means that causes plastic deformation by the action of mechanical force. . 4. The tube and flange according to claim 1, characterized in that a plurality of small protrusions are provided almost uniformly on the inner surface of the tube insertion hole as a joining means that causes plastic deformation by the action of mechanical force. joining method. 5. Claim 1, characterized in that, as a joining means that causes plastic deformation by the action of mechanical force, the outer circumferential surface of the tip of the tube is knurled so that a plurality of small protrusions are protruded almost uniformly. The method of joining the pipe and flange described in section. 8. As a tube insertion hole, a locking step is formed at the terminal end, and a required hole formed thinner than the thickness of the flap and the lung in the space formed by the locking step and the side wall of the tube insertion hole. A method for joining a pipe and a flange according to claim 1, 2, 3, or 4, characterized in that a flange having a pipe insertion hole with a caskerat inside is used.