JPS5912469Y2 - flange pipe - Google Patents

Description

[Detailed explanation of the idea] The present invention relates to a flange pipe made of cast iron pipe.

When manufacturing a tube with flanges at both ends by centrifugal casting,
Since it becomes difficult to extract the product from the mold, a tube having a flange at only one end is cast, and then a flange member is fixed to the other end.

In addition, even in the case of a tube with a flange on only one end, the flange may become wavy or tilted during the annealing stage, which may cause a seal failure when connecting the tube, so a separately shaped flange member is attached to the tube body. It is advantageous to stick.

As such a flange pipe, as shown in FIG. 2, a flange member 23 having a flange 22 protruding from the outer periphery of a cylindrical portion 21 has been proposed.

The end face 23a at one end of the flange member 23 constitutes a sealing surface and cannot be welded to the tube body 24, and only the other end is welded to the tube body 24.

However, if only one end is fixed in this way, the resistance to the bending moment in the direction of the arrow that acts on the flange 22 during piping conditions and handling is weak.
In order to obtain sufficient stability, it is necessary to increase the length l of the cylindrical portion 21.

Therefore, material costs increase. Moreover, it is necessary to make the build-up of the weld 25 sufficiently large.

The present invention solves the above problem by fitting a flange member formed by protruding a flange on the outer periphery of a cylindrical part to the end of a cast iron pipe body, and at least the inner circumferential portion of the end face of the pipe body. an annular notch recess is provided in the flange member, an annular engagement projection whose side surface can be engaged with the notch recess of the tube body is provided on the inner periphery of one end of the flange member, and the other end of the flange member is connected to the outer surface of the tube body. An example of this will be described below with reference to FIG. 1.

1 is a cast iron tube body, and 2 is a flange member.

The flange member 2 consists of a cylindrical portion 3 and a flange 4 protruding from the outer periphery of the cylindrical portion 3, and is fitted onto the end of the tube body 1.

5 is a bolt hole provided in the flange 4 for pipe connection.

An annular notched recess 6 having a tapered surface is provided on the inner periphery of the end surface of the tube body 1, and an annular engaging protrusion 7 whose side surface engages with the notched recess 6 is provided on the inner periphery of one end of the flange member 2. There is.

That is, the inner peripheral side of the side surface of the engagement protrusion 7 protrudes in a tapered shape so as to fit tightly into the notch recess 6 .

The cutout recess 6 may extend over the entire thickness of the tube body 1, or may be provided only in the inner peripheral portion.

The inner diameter of the annular protrusion 7 is the same as the inner diameter of the tube body 1.

The other end of the flange member 2 is welded 8 to the outer surface of the tube body 1.

With this structure, the engaging protrusion 7 of the flange member 2 engages with the notch recess 6 of the tube body 1 at one end, and is fixed by welding 8 at the other end, so both ends are supported. Become.

Therefore, even if the length of the cylindrical portion 3 in the tube axis direction is short, strong resistance to the bending moment acting on the flange 4 can be obtained, and stability of the flange 4 can be obtained.

Furthermore, only a small amount of overlay for the weld 8 is sufficient.

In addition, since the inner side surface of the engaging protrusion 7 engages with the tube body 1, the outer surface, that is, the contact surface 9 that contacts the other tube body of the flange member 2, can be shaped smoothly, ensuring reliable sealing. can be achieved.

Note that the cutout recess 6 of the tube body 1 may be cut out to have a rectangular cross-section, but if it is shaped with a tapered surface as in this embodiment, it will be difficult to fit the flange member 2 into the tube body 1. Even if the pipe body 1 or the flange member 2 is distorted within the tolerance when the tube body 1 or the flange member 2 is bent, there is no problem such as catching on the outer periphery of the notch recess 6 until the engaging protrusion 7 is tightly fitted into the notch recess 6. Insertion can be performed smoothly.

As explained above, according to the present invention, the side surface of the engaging protrusion at one end of the flange member is engaged with the notch recess provided in the end face of the pipe body, and the welded part at the other end and the flange member are fixed at both ends. As a result, the flange is strong against the bending moment acting on the flange, and the cylindrical portion of the flange member can be made short.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention, and FIG. 2 is a partial sectional view of a conventional flange pipe. DESCRIPTION OF SYMBOLS 1... Pipe body, 2... Flange member, 3... Cylindrical part, 4... Flange, 6... Tapered concave surface part, 7...
...Engaging protrusion, 8...Welding.

Claims (1)

[Scope of utility model registration request] A flange member having a flange protruding from the outer periphery of a cylindrical portion is fitted onto the end of a cast iron pipe body, an annular notch recess is provided at least on the inner peripheral portion of the end face of the pipe body, and the flange member is A flange pipe, characterized in that an annular engaging protrusion whose side surface can be secured to the notch recess of the pipe body is provided on the inner periphery of one end, and the other end of the flange member and the outer surface of the pipe main body are welded.