JPS5947615B2 - Method for manufacturing heat transfer plates and press mold for the same manufacturing - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing heat transfer plates used in plate heat exchangers that do not cause deflection or distortion using a small press machine.

Generally, as shown in Fig. 1, in a plate heat exchanger, a liquid flow path with an uneven pattern is formed on a heat transfer plate 1 by press working, a liquid seal gasket 3 is attached to this, and a hot liquid side flow path is formed. The plates 1 are stacked one on top of the other, and the plates 1 are tightly tightened with bolts between the two frames 2 so that the cold liquid side channels are arranged alternately.

Such a plate heat exchanger has very large advantages, such as having a significantly higher heat transfer coefficient than other heat exchangers, being compact, and being easily disassembled and assembled.

However, when press forming the heat transfer plate 1, it is difficult to form the heat transfer plate 1 due to the presence of many uneven patterns (also, even a slight uneven pattern in the center causes the plate to warp or bend, especially when using materials such as stainless steel or titanium). As the material becomes harder, normal machining becomes increasingly difficult.

Therefore, in order to suppress the occurrence of distortion, it is necessary to form the entire uneven pattern and the five liquid flow paths on the heat transfer plate 1 in one strong press process. As the power of presses increased, equipment costs rose significantly.

Furthermore, since it is not possible to unnecessarily increase the size of the press machine, the size of the heat transfer plate is inevitably limited. Partly, the heat transfer plate is divided into several equal parts,
A proposal has been made to form the irregularities in this divided area using one press process and the remaining parts by punching, but this method still causes bending and loosening, making it unsatisfactory as a heat transfer plate. It wasn't.

In view of these drawbacks, the present invention has been developed to form heat transfer plates using a small press machine that is approximately one-tenth to one-tenth of the size of conventional presses, even with hard materials such as stainless steel and titanium, without causing bending or distortion. This method provides a method for manufacturing a heat transfer plate for a plate heat exchanger, in which continuous grooves, which become protrusions when viewed from the back side, are formed in the periphery of the heat transfer plate.
Then, a wavy portion in which peaks and troughs are consecutively arranged in the inner portion is set as one block, and a plurality of the wavy portions in the longitudinal direction of the heat transfer plate and the continuous groove of a constant length are set as one block, and the continuous groove of the peripheral portion is set as one block. When forming in multiple steps so that the grooves and the wavy portions on the inner part partially overlap each other, in the previous step, the vicinity of the edge of the block is pressed gradually shallowly in the direction of the edge into a boat-shaped shape. In the method of manufacturing a heat transfer plate and the method of manufacturing a heat transfer plate for a plate heat exchanger, the shallowly pressed portion is pressed to a final depth in the next step. A continuous groove that becomes a protrusion when viewed from the back side is formed on the peripheral part of the plate, a wavy part in which peaks and troughs are connected in a row is formed on the inner part, and the wavy shape is further transmitted to the outer part of the continuous groove in the peripheral part. The second wavy portion appearing on the edge of the heat transfer plate is defined as one block including a plurality of the wavy portions in the longitudinal direction of the heat transfer plate, the continuous groove of a constant length, and a plurality of the second wavy portions, and When molding is performed in multiple steps so that the continuous groove of the protrusion, the wavy portion in the inner portion, and the second wavy portion overlap each other, in the previous step, the bottom of the prong is formed near the edge in the direction of the edge. Pressing into a mold shape gradually to make it shallower,
In the next step, the shallowly pressed portion is pressed to a final depth. In the above-mentioned method, which is characterized in that the molding is performed before and after the molding of the parts and the continuous grooves, and in the press die for manufacturing the heat transfer plate in the plate type heat exchanger, the corrugated part with the ridges and troughs successively arranged in the inner part is formed. an upper mold having a protrusion for forming continuous grooves on the peripheral part, and a boat-bottom-shaped relief part at the front and back of the wavy part and the protrusion, or either one thereof facing in the molding direction; The present invention relates to a press mold for manufacturing a heat transfer plate, characterized in that it is composed of a lower mold having an uneven portion complementary to the upper mold.

This has made it possible to manufacture heat transfer plates with high precision at low cost and without bending or distortion.

Furthermore, by increasing the power of the press, it became possible to manufacture much larger heat transfer plates than conventional plates of the same size.

Next, the present invention will be explained with reference to the drawings.

2. The heat transfer plate blank 8 shown in FIG. 1 is formed by one press in the first step as shown in FIG. A plurality of wavy portions 5 (first wavy portions) are provided with linear continuous grooves 6 of a certain length that serve as gasket insertion grooves on both outsides thereof (this continuous groove becomes a convex strip on the back side), and further as the case may be. In order to improve the flatness of the heat transfer plate and to make it flexible, a portion of the uneven pattern is formed at its outer end, each completing a plurality of second corrugations 7 in which corrugations appear at the edges of the heat transfer plate.

(In Figure 2, the wavy parts and grooves are shown as lines.) When forming the wavy parts and grooves, the protrusions of the press die are placed on the unprocessed parts in the vertical direction of the heat transfer plate in Figure 2. At the front, it should be formed shallowly into the shape of the bottom of a boat.

This shallowly molded portion is shown as a dotted portion in FIG. Therefore, in a certain range 9 in the upper and lower parts of the press molding pattern shown in FIG. 2, the corrugated parts 5 and the grooves 6 are formed shallowly.

Further, the mold of the press machine has shapes 11, 12, and 13 that enable this molding, as shown in FIGS. 14 is configured to have a boat bottom-shaped relief part.

Next, as shown in FIG. 2, in the second step, the wavy shape formed in the first step is formed using the same mold as in the first step, or using a different mold if the shape is different. Part 5, T (first and second wavy parts) and continuous groove 6
Press so that they partially overlap.

By pressing in this second step, the shallowly worked portion in the first step is reduced to a predetermined depth of the wavy portions and grooves (
(indicated by 10 in Fig. 2), and is machined deeply.

At the same time, in the second process, the lower part of the press die
However, some corrugations and grooves are machined to a shallower depth than the final depth. The boat bottom mold part above this press mold is located in a part that has already been pressed to a predetermined depth, so it does not affect the molding. By repeating the above steps, as shown in Fig. 2, the same corrugated portion and continuous groove for gasket insertion are formed by multiple pressing processes, except for the vicinity of the upper and lower fluid flow holes, by the required length. Press each part to make sure they overlap.

In FIG. 2, the central portion is pressed three times, but it can be pressed two or more times. In one press in the above-mentioned one step, on the heat transfer plate,
This causes some bending and distortion, but in the next step, the molded parts are pressed so that they partially overlap, and the same pressing process is performed while absorbing the distortion.

Subsequently, a similar molding process is performed in multiple steps to completely eliminate any deflection or distortion that occurred at the beginning, and to form an extremely flat heat transfer plate. Furthermore, since the press working in the vicinity of the unprocessed portion is carried out using a press mold provided with a boat-bottom relief part as shown in FIGS. 3 to 5, the plate can be processed gently and without strain.

In general, it is common to think that as the number of processing steps increases, the distortion that initially occurs gradually increases, and that the distortion increases as the number of processing steps increases.

However, the molded product according to the present invention effectively absorbs the distortion caused in the previous process in the overlapping pressing process, and
In addition, the distortions generated in each process are made to interfere with each other, and a flat heat transfer plate having an uneven pattern is finally manufactured. This is something that cannot be considered by common sense, and as a result of intensive research and experiments, the inventor of the present application found that
It is finally completed. Although it is possible to form something that is difficult to process in multiple stages using deep drawing D or the like, it goes without saying that this cannot be used to form complex uneven parts such as a heat transfer plate.

After the above-described molding process of the present invention, as shown in FIG. 2V, uneven portions such as distribution grooves and gasket insertion grooves are formed in the vicinity of the portions that will become the fluid flow holes. In this case, almost the entire area has already been hardened by mutual strain interference and absorption by the corrugated portions and grooves, and is further hardened by processing, as shown in Figure 2 V.
In this process, bending and distortion no longer occur. Further, the shallowly formed portions 10 existing above and below the central wavy portion 5 and the continuous groove 6 may be formed simultaneously in the above-mentioned punching press process, or may be formed by a press process in which the distribution groove and the gasket insertion groove are formed separately. At the same time, press working is performed to a predetermined depth.

Conversely, even if the first wavy portion 5, the continuous groove 6, and the second wavy portion 7 in the central portion are formed after punching the fluid flow hole and processing the vicinity of the hole, the process is repeated multiple times in the same manner. After the repeated forming process is completed, the heat transfer plate 8 is formed flat.

Therefore, which step to perform first can be selected in consideration of ease of molding.

The so-called second wavy portion T, which is formed so that a wavy shape appears on the edge of the heat transfer plate outside the continuous groove, has the role of effectively eliminating the occurrence of deflection or distortion.
The presence of this corrugation 1 further increases the flatness and gives rise to flexibility of the plate. In this way, a small press machine is used to form the continuous grooves 6 on both sides of the central wavy part (first wavy part) 5, and the second wavy part T where a waveform appears on the edge of the heat transfer plate outside of the continuous grooves 6. Through multiple pressing processes,
By molding these so that they partially overlap,
It was possible to easily form a flat heat transfer plate, which was previously considered impossible.

An example of a press mold is shown in FIG.

A plurality of herringhorn-shaped (herringbone pattern) wavy convex portions (first wavy portions) 11 are present inside this mold. Continuous linear convex portions 1 extending vertically on both outer sides of this herringhorn convex wave.
2 and a convex portion 13 for forming a transverse wave (second wavy portion) connected thereto.
There is. The press die shown in FIG. 3 is a die that performs one press, and the hatched areas indicate the areas where the presses are overlapped.

The protruding part of the press die in the outward direction of the diagonally shaded part has a boat-bottom relief part, and has a shape that is formed to become gradually shallower during pressing. This breath-type first wavy portion can be of any shape, such as a herringhorn, parallel corrugate, oblique parallel corrugate, interrupted wave, or petal shape. Furthermore, the heat transfer plate obtained according to the present invention can be employed in general plate heat exchange.

As described above, the present invention makes the press machine smaller and
Heat transfer plates can be manufactured at low cost, and if the press machine is made larger, even larger heat transfer plates can be manufactured.

[Brief explanation of drawings]

Fig. 1 is an exploded perspective view of a plate heat exchanger, Fig. 2 is an explanatory diagram showing the manufacturing steps of the method of the present invention, Fig. 3 is a plan view showing an example of the press mold of the present invention, and Fig. 4 is shown in Figure 3
The sectional view, FIG. 5, is a sectional view taken along Y-Y in FIG.

Claims (1)

[Claims] 1. A method for manufacturing a heat transfer plate for a plate heat exchanger, in which continuous grooves are formed in the peripheral part of the heat transfer plate as seen from the back side, and peaks and valleys are connected in the inner part. A plurality of the wavy portions in the longitudinal direction of the heat transfer plate and the continuous groove of a certain length are considered as one block, and a portion of the continuous groove in the peripheral portion and the wavy portion in the inner portion are respectively When forming in multiple steps so that each block overlaps, in the previous step, the vicinity of the edge of the block is pressed gradually shallower in the shape of a boat bottom in the direction of the edge, and in the next step, the shallowly pressed portion is made to have the final depth. A method for manufacturing a heat transfer plate, characterized by press working. 2. In the method of manufacturing a heat transfer plate for a plate heat exchanger, continuous grooves that become protrusions when viewed from the back surface are formed on the peripheral portion of the heat transfer plate, and a wavy portion with continuous peaks and valleys is provided on the inner side, Furthermore, a second wavy portion in which a waveform appears on the edge of the heat transfer plate is provided on the outer side of the continuous groove in the peripheral portion, and a plurality of the wavy portions in the longitudinal direction of the heat transfer plate and the continuous groove of a constant length; When molding a plurality of second wavy portions as one block in a plurality of steps so that the continuous groove in the peripheral portion, the wavy portion in the inner portion, and the second wavy portion overlap each other, a pre-process. In,
Production of a heat transfer plate, characterized in that the vicinity of the edge of the block is pressed gradually shallower in the shape of a boat bottom in the edge direction, and in the next step, the shallowly pressed portion is pressed to a final depth. Method. 3. The method according to claims 1 and 2, characterized in that the fluid flow holes of the heat transfer plate and the concavo-convex portions in the vicinity thereof are formed before and after the wavy portions and continuous grooves are formed. 4. In a press mold for manufacturing a heat transfer plate in a plate heat exchanger, a wavy part with consecutive peaks and troughs is provided on the inner part, a protrusion for forming continuous grooves is provided on the peripheral part, and the above-mentioned shape in the molding direction is provided. It is composed of an upper mold having a boat-bottom shaped relief part at the front and back of the wavy part and the protruding part, or either one thereof, and a lower mold having an uneven part complementary to the upper mold. A press mold for manufacturing heat transfer plates with special features.