JPS60118332A - Manufacture of porous plate provided with projection - Google Patents

Abstract

PURPOSE:To prevent cracks on the way of forming a cylindrical projection, and to raise the forming efficiency of a porous plate provided with a projection by piercing a stepped through-hole of a small diameter at a clad side of a large diameter in a base plate side of a clad plate formed by joining a clad layer to one surface of the base plate, and thereafter, executing burring to the clad layer. CONSTITUTION:A cald steel plate 1 which has joined a clad layer 1b consisting of a material which is large in elongation and low in strength, to a base material 1a consisting of a material having high strength is prepared. Subsequently, a circular hollow 4 of a large diameter D0 is pierced in the base plate 1a, a center hole 5 of a small diameter (d) is pierced in the clad layer 1b, a stepped through-hole of t1=tc is pierced, and a bottom part 6c is formed. Next, a tapered turning cylindrical tool 7 of a diameter D0 is turned and pushed into the stepped through-hole, the bottom part 6c is brought to burring, and a projecting part 8c is formed on the clad layer 1b. Also, the tool 7 is made to pass through a through-hole 3 and a circular projection 2c of a height (h) is formed on the clad layer. In this regard, as for the step difference, even if the bottom part of the through-hole is formed to t1<tc, the same effect as above is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a perforated plate with protrusions for use in a moisture separator or a tube plate for various shell-and-tube heat exchangers.

Conventionally, as shown in FIG. 1, a substrate 01 having a thickness to has a circular hole protrusion 02 having a protrusion height h. In order to manufacture a perforated plate with protrusions in which passage holes 03 are formed by burring, a procedure already proposed by the present inventor shown in FIG. 2 is carried out.

That is, (a) prepare a substrate 01 with a thickness to, and (b) leave a bottom part 06 of a thickness tl on the substrate 01 and deepen it to a depth to-tl).
After pre-drilling a circular depression 04 with a diameter of , a center hole 05 for burring with a diameter α is formed in the bottom 06 of a thickness tl.
(c) A protrusion forming tool 07 that moves forward and backward or while rotating is pushed into the surface of the substrate 01 perpendicularly along the circular depression 04 to perform burring on the bottom part 06 to form a protrusion 08. By molding, a substrate 01 having circular hole protrusions 02 is formed.

By the way, when the perforated plate with protrusions shown in Fig. 1 is used, for example, as the first-stage collision plate of a moisture separator that separates a two-phase flow of vapor and liquid, the protrusions of the perforated plate prevent water film flow. This has the effect of preventing the flow of water into the steam passage, and is effective for gas-liquid separation.

However, as a material for the perforated plate with protrusions, JIS G
Carbon steel sheet SB1 for boilers and pressure vessels, molybdenum steel sheet SB-M, chromium molybdenum steel sheet SCMV, etc. are used in , so the elongation value is low, as shown in Figure 3.
A crack 09 is generated in the axial direction of the circular hole projection (part of the collar) 02.

As a measure to prevent such cracks, it is possible to heat the substrate 01 and perform thermal release molding, but the workability is poor, and
This method has the drawback of causing seizure of the tools used during hot forming or shortening the life of the tools.

The present invention solves the above-mentioned drawbacks, and prevents the occurrence of cracks at the peripheral edges of the circular hole protrusions during the burring process of a perforated plate with protrusions, improves workability, extends the life of the forming tool, and improves the burring process. It is an object of the present invention to provide a method for manufacturing a perforated plate with projections that can increase the height of the hole projections (parts of the holes).

In order to achieve the above object, the present invention uses a clad plate in which a substrate serving as a strength member and a cladding layer serving as a member forming circular hole protrusions are integrally joined as a base plate of a perforated plate with projections. , this clad plate has a large diameter on the substrate side,
When creating a stepped through-hole with a small diameter on the cladding layer side, after pre-machining so that the stepped part of the stepped through-hole is chamfered to the cladding layer joining surface or a part of the cladding layer, use a bullet-shaped cylindrical tool to cut the stepped through-hole. The method of manufacturing a perforated plate with protrusions is characterized in that the cladding layer is rotated and pushed into a through hole with protrusions, the cladding layer is burred, and the protrusion is formed into a cylindrical shape.

Embodiments of the present invention will be described below with reference to the drawings.

What is shown in Fig. 4 is (a) a base material 1a made of a material such as a high-strength ordinary steel plate to serve as an element for maintaining strength;
and thickness tc, pure iron such as carbonyl iron, copper,
A cladding steel plate 1 having a total thickness to is prepared by joining a cladding layer 1b made of a material with high elongation and low strength, such as aluminum, by explosion bonding, pressure bonding, diffusion bonding, or the like. In addition, firepower,
Preferably, pure iron is used as the cladding layer for nuclear moisture separators.

(b) Next, a circular depression 4 with a large diameter Do is bored in the substrate 1a, and a center hole 5 with a small diameter d is bored in the cladding layer 1b. That is, if the preset thickness of the bottom is tl, then tl=tc
A stepped through hole is bored in the clad steel plate 1, and a bottom portion 6c is formed in the clad layer.

The stepped through hole can be punched with a stepped punch having a tip portion having a diameter d1 and a length tc, and a base portion having a diameter Do1 and a length t6-tc.

(c) Then, a bullet-shaped tapered rotary cylindrical tool 7 with a diameter of DO
is rotated and pushed into the stepped through hole, and the bottom portion 6c is burred to form the protruding portion 8c in the cladding layer 1b.

b) Penetrating the diameter Do portion of the tool 7 into the through hole 3,
A circular hole protrusion 2C having a height h is formed in the clad layer of the clad steel plate 1.

What is shown in FIG. 5 is another example in which the relationship between the bottom level and the clad layer is changed when drilling stepped through holes in the first step of processing a perforated plate with projections, and the relationship between the bottom level and the cladding layer is changed. The thickness tl of the bottom portion is made larger than the thickness tc of the cladding layer. In this case, the stepped through hole has a tip with a diameter d1 and a length tc, and a diameter Do1 with a length to-t (however, t
The hole can be punched using a two-stage punch having a base portion having a diameter of 1 (tc) and a base portion having a diameter of 1 (tc). Other operations are similar to the processing method shown in FIG.

Note that when drilling the stepped through hole in the clad steel plate 1, the preset bottom thickness tl is the cladding layer thickness tc.
It is not preferable for processing to make the thickness extremely thin compared to (t 1 << tc).

FIG. 6 shows another embodiment of the present invention in which the cladding layer is deep drawn.

That is, (a) a clad steel plate having a total thickness to is prepared by bonding a base material 1a and a clad layer 1b having a thickness tc.

(b) Diameter on the substrate 1a. A circular recess 4 is bored out.

(C) Place the cladding layer 1b on the die 11, press the holder 12 from above the base material 1a, and push the punch 13 with a diameter into the circular depression 4 to form a cup portion with a height hl on the cladding layer. Mold 9.

) Next, the diameter (D11D1≦D,
) is drilled with a bottom hole 10.

(E) A bullet-shaped turning tool 7 having a diameter Do is turned and pushed into the cup portion 9 to penetrate the bottom hole 10 to form the through hole 3;
A circular hole protrusion 2c having a height h 2 (hz >ht) is formed in the cladding layer 1b.

As described above, according to the pearling method of the present invention, since the cladding layer is made of a material with high elongation and low strength, the outer periphery of the circular hole protrusion is Cracks do not occur during the process of lengthening, improving processing efficiency.

In addition, the inner wall of the through hole is not dented due to burring, and the deformation resistance due to molding is low, so the equipment capacity can be reduced. Furthermore, since the cladding layer has a large elongation, the diameter of the pre-drilled hole in the cladding layer can be reduced, and therefore the height of the circular hole protrusion can be increased.

Note that when the stepped portion of the stepped through-hole is chamfered to a part of the cladding layer, there is an effect that the cladding layer does not peel off.

In the above embodiments of the present invention, a clad steel plate was used as the material for the perforated plate with protrusions, but any other material other than steel plate may be used as the material for the substrate as long as it achieves the effects of the present invention.・It may be a clad plate using a die, a 12 mm holder, or a material. In addition, the present invention is not limited to the embodiments described above and shown in the drawings, and it goes without saying that the present invention may be implemented with appropriate modifications within the scope of the invention.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view in the plate thickness direction of a conventional perforated plate with protrusions;
The figure is a process cross-sectional view showing the steps of a conventional method for manufacturing a perforated plate with projections, Fig. 3 is a partial front view of a perforated plate with protrusions showing a state in which cracks occur in the conventional circular hole protrusions, and Fig. 4 is a main view of the present invention. FIG. 5 is a process sectional view showing the steps of a method for manufacturing a perforated plate with protrusions according to an embodiment of the present invention; FIG. FIG. 7 is a process sectional view showing the steps of a method for manufacturing a perforated plate with projections according to still another embodiment of the present invention. 1.O clad steel plate, 1a.. Substrate, 1b.. Clad layer, 2C-φ circular hole protrusion (partial empty), 3.. Through hole, 4
...Circular depression, 5.Center hole, 6c.Bottom, 7.Cannonball-shaped tapered rotating cylindrical tool, 8c.Protrusion during molding.
9.Cup part, 10.-(8) 13@.Bunch

Claims (1)

[Claims] A clad plate made of a highly ductile material of a predetermined thickness is bonded to one side of the substrate, which will serve as a strength member, in advance.
In the method for manufacturing a perforated plate with protrusions, in which a stepped through hole having a large diameter on the substrate side and a small diameter on the cladding layer side is burred, the step portion of the stepped through hole is formed on the cladding layer bonding surface or on the cladding layer bonding surface. A method for manufacturing a perforated plate with protrusions, which comprises performing preliminary processing to chamfer a portion of the layer, and then rotating and pushing a tapered small cylindrical tool into the stepped through-hole to perform burring on the cladding layer.