JP2006015388A - Super minute fin folding method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve such a problem that, since a material reinforced by adding alumina to copper is brittle and hard, a punch is not drawn out of a die in the state of folding a super minute fin, a bent part of a thin plate is irregularly thin, cracks are generated therein and the thin plate is hardly folded. <P>SOLUTION: Rugged super-fine fins can continuously be folded from a thin plate by alternately moving two punches in the vertical direction as shown in Figure. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method of folding fine fins for uneven heat exchangers used in the nuclear industry, general industry, automobiles, aerospace, and the like using ultra-small to large heat exchangers used at high temperature and pressure.

Conventional technology

  Conventionally, in the method of folding uneven heat exchanger fins, the hat method is generally used to process uneven fins by processing a thin plate with a single punch and then repeating this process. In this case, it is difficult to process a fine fin because the punch bites into the processed surface and cannot be removed.

  In order to improve the performance of a compact heat exchanger in which offset fins are laminated, it is effective to process an alloy thin plate having high thermal conductivity as finely as possible to process it into a concave and convex offset fin. Therefore, it is effective to process fins using a copper material with high thermal conductivity, but it is effective to use a heat exchanger at a high pressure, offset fins using a thin plate made of alloyed copper and strengthened. Must be processed. However, the material strengthened by adding alumina to copper is brittle and hard, so the punch cannot be removed from the processing mold at the stage of processing the fine fins, or the processed bending part of the thin plate becomes abnormally thin, causing cracks, etc. Have difficulty.

Means to solve the problem

  In the present invention, the uneven fine fins can be continuously processed from the thin plate by alternately moving the two punches up and down as shown in FIG. That is, the present invention uses a double action processing machine equipped with an upper fixed soybean, an upper movable soybean, a lower fixed soybean, and a lower movable soybean, and the work material placed on the lower fixed soybean and the lower movable soybean is the upper movable soybean. Is lowered and fixed, the lower movable soybean is raised to form the concave bent portion, and then the upper movable soybean is lowered to form the convex bent portion next to the concave bent portion, thereby removing the alloy thin plate. This is a method of folding a fine fin for an uneven heat exchanger.

The present invention will be specifically described with reference to FIG. 1. After forming the convex bent portion 8 on the work material 7, the work material is moved to the left by one section. The upper fixed soybean 2 is lowered onto the workpiece material placed on the lower stationary soybean 1 and the lower movable soybean 3 to fix the workpiece material. The lower movable soybean 3 is raised to form the concave bent portion 9. Next, the upper movable soybean 4 is lowered while the lower movable soybean is left as it is, and the convex bent portion 10 is formed. After the bent portions 9 and 10 are formed, all soybeans are raised or lowered to move the material to be processed to the left by one section, and the same forming process is repeated to produce uneven fins.
[The invention's effect]

  The present invention is a technology that enables the manufacture of ultra-small to large-sized heat exchangers that are used at high temperatures and pressures as compactly and lightly as possible. Further, since complex microfabrication can be performed continuously, an extremely wide range of application fields is expected. Is done.

  In normal fin processing, the fin is processed into a fin shape through complicated processing steps such as bending while bending and bending / unbending without being processed into a fin shape by simple bending. Since lifting and bending while processing a hard and brittle alloy thin plate and bending while receiving tension, the material may be severely deformed and may cause breakage. Therefore, in the present invention, the double action processing method described later is adopted. The feature of this processing method is that it suppresses the reduction of the plate thickness and prevents cracks by suppressing the tension on the material as much as possible without restricting the inflow of the material on one side.

  FIG. 2 shows a double action processing machine. This machine incorporates four dies: a lower fixed die 1, an upper fixed die 2, a lower movable die 3, and an upper movable die 4. The lower movable die is fixed to the lower movable plate, the upper movable die is fixed to the upper movable plate, the upper movable plate is the upper hydraulic cylinder 5 built in the machine, and the lower movable plate is guided by the lower hydraulic cylinder 6 built in the machine. Is driven up and down.

  FIG. 3 shows the shape and dimensions of a typical upper die. The lower movable die 3 is fixed to the lower movable plate, and the upper movable die 4 is fixed to the upper movable plate. The upper movable plate is the upper hydraulic cylinder built in the processing machine, and the lower movable plate is four by the lower hydraulic cylinder built in the processing machine. Guided by the guide post, it is driven up and down.

The fin folding test procedure using this double-axis machine is shown below.
(1) A double action processing machine is installed on the head (Polsta) of a material testing machine.
(2) Turn the dice interval adjustment knob to adjust the space between the upper and lower dies so that the molded test material can pass (about 4 to 8 mm).
(3) Lubricating oil (with a sulfur-based extreme pressure agent added) is applied to the front and back of the test piece in advance, and inserted along the guide from the testing machine entry side. Thereafter, the material testing machine ram is driven, and the test piece is fixed with the upper and lower fixing dies.
(4) Apply hydraulic pressure to the lower oil cylinder to raise the lower movable die and bend the test piece. Further, the hydraulic pressure is applied to the upper hydraulic cylinder while maintaining the hydraulic pressure of the lower hydraulic cylinder, the upper movable die is lowered, and the test piece is bent. Unload in the order of the upper hydraulic cylinder and the lower hydraulic cylinder, raise the upper movable die, and lower the lower movable die. The material testing machine is unloaded and the testing machine ram is raised until the vertical fixed die interval is close to the value set in (2). Move the test piece to determine the next machining position. After confirming the processing position of the test, the material testing machine ram is driven and the test piece is fixed with the upper and lower fixing dies. Thereafter, the procedure (4) is repeated. FIG. 4 shows the fin processed by the above procedure.

  The method of the present invention can fold straight fins or offset fin type fine fins for heat exchangers as shown in FIG. 5 from a heat-resistant and high-strength alloy thin plate, so that an intermediate heat exchanger or gas turbine of a high-temperature gas furnace The pressure resistance performance, heat exchange efficiency and compactness of the regenerative heat exchanger can be remarkably improved, which is effective for improving the economic efficiency of these nuclear power plants.

It is a figure which shows the process sequence of a double action processing method. It is a figure which shows a double action processing machine. It is a figure which shows a double action processing machine upper die typical shape and a dimension. It is a figure which shows the fin processed by the double action processing method. It is a figure which shows a straight fin or an offset fin.

Explanation of symbols

1: Lower fixed soybean 2: Upper fixed soybean 3: Lower movable soybean 4: Upper movable soybean 5: Upper water pressure cylinder 6: Lower water pressure cylinder 7: Work material 8: Convex bent part 9: Concave bent part

Claims (7)

  A method of folding uneven fins for heat exchangers from heat-resistant and high-strength alloy sheets.   2. A method according to claim 1, wherein the uneven fins are continuously folded from the alloy sheet by alternately raising and lowering a pair of dies.   The method according to claim 1, wherein when the uneven fin is folded from the heat-resistant alloy thin plate, it is folded without leaving a residual stress as much as possible in the folded portion.   The method according to claim 1, wherein an offset and a straight fin having a thickness of 0.0 mm or more, a height of 1 mm or more, a width of 1 mm or more, a pitch of 1 mm or more, and an offset of 5 mm or more are processed from the heat-resistant alloy sheet.   The method of Claim 1 which processes the offset and straight fin which were processed from the heat-resistant high-strength alloy thin plate which can be endured with a differential pressure of 4 MPa or more.   The method according to claim 1, wherein the brittle and hard alloy sheet can be processed from room temperature to 1000 ° C. The method according to claim 1, wherein fine offsets and straight fins for compact heat exchangers usable at high temperature and high pressure are processed.