JPS58224024A - Formation of welded flange part of tube plate for multitubular heat exchanger - Google Patents

Abstract

PURPOSE:To form a titled flange part at high working efficiency by piercing a hole in the tube plate with a drill, expanding the upper part of the hole with a facing rod, pushing down a working roll while rotating it, and protruding the lower part of the hole to lower face. CONSTITUTION:A hole 2 is pierced in a tube plate 1 with a drill 3. The plate 1 is cut from above with a facing rod 4 having outer diameter slightly larger than the hole 2 to the part shown by slanter lines, leaving a specified thickness L at lower end of the hole 2. Then, it is placed on a die 6 provided with a concavity or a hole 5 having inner diameter slightly larger (corresponds to the thickness L of the hole) than the diameter L2 of the part 2a cut and expanded by the facing rod 4. It is then pressed by rotating and pressing a working roll 8 provided with pressing rolls 7 arranged at equal spaces on the outer periphery and incorporated in the frame allowing independent free rotation and the part L of the hole 2 is pressed and bent by the slanted faces 7a of the rolls 7 against the lower face of the tube plate 1. Thus, a welded flange 1a is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for forming a welded flange portion 2 of a tube sheet for a multi-tubular heat exchanger.

As shown in Fig. 1, the welded flange part of a conventional multi-tube heat exchanger tube sheet is removed by cutting the shaded part a on the body side of the tube sheet A, thereby forming the welded flange part of the tube C. Part B
was forming. However, this method of machining the circumference of the tube hole has the disadvantage that it is very labor intensive when there are a large number of tubes, and the productivity is low due to poor working efficiency.

The present invention has been devised to improve these drawbacks, and will be described in detail below with reference to FIGS. 2 to 5. First, as shown in Fig. 2A, drill a hole 2 in the tube plate 1 with the drill 3. Next, as shown in Fig. 2, open the hole 2 from above the tube plate 1. The diameter of the hole 2 is also slightly larger than the outside diameter. Using a counterbore rod 4, cut to the shaded area to leave a novel thickness at the lower end of the hole 2. Next, as shown in FIG.
It is placed on a die 6 provided with a recess or a through hole 5 having an inner diameter slightly larger than the diameter L2 of a (corresponding to the thickness of the hole 2). Pressure rolls 7, each of which is independently rotatable and incorporated into the frame, are installed on the outer periphery at equal intervals in the circumferential direction, and the operation rolls 8, which are rotated by a required rotational drive device, are rotated and pressed down. Apply pressure. In this way, the thick portion where the hole 2 remains is the inclined surface 7 of the pressure roll 7.
a is pressed against the lower surface of the tube plate 1, and the second
As shown in Figure 1, a welding flange 1a of the pipe is formed. (Support) The rotation of the operating roll 8 is achieved by fixing the operating roll 8 to a rotating HQ11 of a drive motor 10 supported on a radial drilling machine 9 and operating the drive motor 10, as shown in FIG. In addition, the diameter of the line connecting the outer peripheries of the pressure rolls 7.7... in the actuating roll 8 is the same diameter as the enlarged part 2a of the hole 2, or is slightly thicker, and the pressure rolls 7.7... The tips of ... are (,., 1□,
Kara. Aya□.

The diameter is equal to or slightly smaller than the diameter of the hole 2. As described above, according to the present invention, the portion 1a can be formed by drilling with a drill and counterboring rod and bending by pressing. Therefore, compared to conventional cutting methods, work efficiency is improved and productivity can be significantly increased.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of the conventional forming method, A is a longitudinal cross-sectional view of the tube sheet, the mouth is a bottom view -1 Fig. 2 is an explanatory diagram of the forming method according to the present invention, and Fig. 3 is an operating roll FIG. 4 is a sectional view taken along the line A--A in FIG. 3, and FIG. 5 is an explanatory view of the operating roll fixed to the drive device. 1... Tube plate C... Hole 2a...
... Enlarged part of the hole 3 ... Drill 4 ...
...Counterbore rod 5...Recess or through hole 6...
... Dice 7 ... Pressure roll 8 ...
...Operating roll 9...Radial drilling machine 1
0... Drive motor 11...Rotating axis Fig. 1 (In (,0) Fig. 2 (A) (Ron Fig. 3 Fig. 1 Fig. 4 Fig. 5

Claims (1)

[Claims] After drilling holes 2 in the tube sheet 1 with a drill 3, etc.,
From above, the diameter of the hole 2 is slightly larger and the counterbore rod 4, which has an outside diameter, is used to cut and enlarge the upper side of the hole 2, leaving a slight thickness at the lower end of the hole 2, and then the tube plate 1 is cut. , that hole 2
The enlarged part 2a is placed on a die 6 having four parts or through holes 5 having an inner diameter slightly larger than the diameter of the enlarged part 2a, each of which is rotatably supported independently, and the lower end is formed into a curved or conical part. Pressure rolls 7 having a shape of 1.5 mm are placed on the outer periphery at equal intervals in the circumferential direction, and an operating roll 8 rotated by a necessary rotation drive device is pressed down while rotating, and the lower end inclined surface 7a of the pressure roll 7 is held to open the hole 2. A method for forming a welded flange portion of a tube sheet for a multi-tubular heat exchanger, characterized in that the remaining thick portion is bent to protrude from the lower surface of the tube sheet 1, thereby forming a welded flange portion 1a.