Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21D22/00—Shaping without cutting, by stamping, spinning, or deep-drawing
  • B21D22/02—Stamping using rigid devices or tools
  • B21D22/027—Stamping using rigid devices or tools for flattening the ends of corrugated sheets
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21D13/00—Corrugating sheet metal, rods or profiles; Bending sheet metal, rods or profiles into wave form
  • B21D13/02—Corrugating sheet metal, rods or profiles; Bending sheet metal, rods or profiles into wave form by pressing
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21D53/00—Making other particular articles
  • B21D53/02—Making other particular articles heat exchangers or parts thereof, e.g. radiators, condensers fins, headers

Definitions

• the present invention relates generally to heat exchangers and more particularly to a method and apparatus for use in the formation of thin metal plates used in such heat exchanger.
• a stacked plate heat exchanger of the type des ⁇ cribed is illustrated by United States Patent No. 3,759,323 to Harry J. Dawson et al.
• the header sections extend transversly to the corruga ⁇ tions, and as the corrugations in the header sections are flattened, the corrugations expand and often completely or partially block the fluid passages defined by adjacent corrugations. Attempts to al ⁇ leviate this problem have not been satisfactory.
• comb-like devices have been employed in an attempt to open the blocked passages following the crushing of the header section corrugations, but since the blockages are irregularly spaced, the regularly spaced comb devices sometimes contribute to the blockage instead of removing it.
• the present invention provides a novel method for flattening corrugated heat ex ⁇ changer plates to form header sections which includes separately and progressively crushing the corruga ⁇ tions in a transition zone between the fluid passages and a header section before forming the remainder of the header section.
• Another aspect of the present invention is to provide a novel apparatus for flattening corrugated heat exchanger plates to form header sections which includes opposed die members for progressively crush ⁇ ing the corrugations in a transition zone, each die member having blades which are maintained on either side of a corrugation to limit the ability of the corrugation to expand or flare outwardly during the cru ⁇ hing operation.
• Figure 1 is a plan view of a corrugated heat exchanger plate which is to be flattened to form header sections in accordance with the present inven ⁇ tion;
• Figure 2 is a diagrammatic illustration of the die assembly of the present invention for receiving a moving heat exchanger plate
• Figure 3 is a cross sectional view of the die set used for the die assembly of Figure 2;
• Figure 4 is a cross sectional view of one die slot and one die blade of the die set of Figure 3 taken along lines 4-4 of Figure 3;
• Figure 5 is a detailed illustration of the detent switches used for the die assembly of Figure 2; and Figure 6 is a circuit diagram of the control circuit for the die assembly of Figure 2.
• Figure 1 discloses a corrugated heat exchanger plate indicated generally at 10 formed from a thin metal or metal alloy sheet which has been corrugated to provide raised ridges having crowns or fins 12 which define intermediate passages 14. These crowns and passages are formed on both sides of the sheet 10, and when the sheet -4-
• the broken lines 16 and 18 in Figure 1 designate header zones 20 and 22 which must be formed on either 5 side of a central corrugated section by flattening the corrugations in the header zones. It is this flattening process which, in the past, has resulted in blockage of the passages 14 in the vicinity of the lines 16 and 18 due to expansion or flaring of 0 the crowns 12 as they are crushed.
• the header zones 20 and 22 may be flattened without resulting in substantial blockage of the passages 14. This is accomplished by progressively 5 crushing each individual crown 12 within transition zones 24 and 26 bordered by the lines 16 and 18 and broken lines 28-and 30 spaced therefrom. Each crown within a transition zone is subjected individually to a plurality of successive crushing steps during 0 which the crown is progressively flattened. During each crushing step, die set support blades are in ⁇ serted into the passages 14 on either side of the crown to act as spacers to prevent the crown from expanding outwardly to block the passages.
• the remainder of the header zones outboard of the transition zones may be easily flattened in a con ⁇ ventional manner to form transversely extending headers on either side of a central corrugated sec- 0 tion.
• the preliminary progressive flattening of the corrugations in the transition zones 24 and 26 may be accomplished by feeding the corrugated heat ex ⁇ changer plate 10 between opposed die members of a 5 die set mechanism which closes once each time the plate moves for a distance equal to the distance between two adjacent crowns 12. As the crowns move beneath the die members, they are progressively re ⁇ ceived in slots of ever decreasing depth as the die members close. At least one passage 14 between the first crown to be crushed and the next adjacent crown to be crushed receives a die support blade which extends into the passage for substantially the total depth thereof to act as a locator blade for following die set blades. This locator blade also stabilizes and reinforces the heat exchanger plate 10 during the flattening operation.
• a novel die assembly 32 constructed in accor ⁇ dance with the present invention is illustrated dia- gra matically in Figure 2.
• This die assembly includes an " upper die 34 and a lower die 36 having opposed die surfaces which are engaged and disengaged by the operation of upper and lower hydraulic cylinders 42 and 44 respectively.
• the upper and lower dies 34 and 36 are connected to hydraulic pistons in cylinders 42 and 44 by rod means 38 and 40, "although other suitable known driving units may be employed to engage and disengage the upper and lower dies.
• the operation of the hydraulic cylinders 42 and 44 is controlled by a die control circuit 46 which controls a valve in each cylinder to cause the rods 38 and 40 to extend or retract. When the rods extend to bring the upper and lower dies 34 and 36 together, the crowns 12 on the heat exchanger plate 10 are crushed.
• the heat exchanger plate 10 is fed between the upper and lower dies 34 and 36 by a suitable drive means such " as opposed driven rollers 48 and 50. Ideally, essentially a continuous feeding motion is imparted to the heat exchanger plate 10, and consequently, the operation of the upper and lower dies must be accurately timed. This timing sequence is accomplished in response to sensing switches 52 54 and 56A and 56B. To comprehend the manner in which the die as ⁇ sembly 32 operates, it is first necessary to consider the structure of the upper and lower dies 34 and 36 as illustrated in Figures 3 and 4. The face of the upper die 34 is formed to provide a plurality of downwardly extending sequential blades 58, 60,
• the face of the lower die 36 is formed to provide a plurality of upwardly extending sequential blades 78, 80, 82, 84, 86 and 88 which are spaced by intervening slots 90, 92, 94, 96 and 98.
• the blades 80-88 enter the slots 68-76 respectively while the blades 58-66 enter the slots 90-98 respectively. It will be noted that some clearance is left between a slot and the blade received thereby to acco odate the heat exchanger plate 10.
• the heat exchanger plate 10 is fed between the upper and lower dies 34 and 36 from the left in Figure 3.
• the blades 58, 78 and 80 constitute entrant blades and are the first blades to enter into passages 14 - in a heat exchanger plate as the plate moves between the dies.
• the blade 58 enters a passage on the top side of the plate while the blades 78 and 80 enter individual passages on the bottom side of the plate.
• These entrant blades and the slots 68 and 90 which receive them are full size and receive and support the heat exchanger plate without crushing the crowns 12.
• a second full sized slot and blade combination 60 and 92 may be provided so that the top and bottom passages 14 are supported by two blades on either side of the heat exchanger plate 10 at the entrant end of the die set.
• the slots 70, 72, 74 and 76 in the top die 34 and the slots 94, 96 and 98 in the bottom die 36 decrease progressively in depth so that the slots 76 and 98 at the exit end of the die set are very shallow.
• the crowns 12 of the heat exchanger plate are progressively crushed as they move into slots of decreasing depth.
• a projection 100 extends from the root of each slot while the opposing blade has a scalloped end as indicated at 102 in Figure 4.
• the structure of the detent switch 52 is shown in greater detail in Figure 5.
• the switch includes a detent ball 104 mounted on a spring arm 106 which spring biases the ball downwardly against the crowns 12 on the heat exchanger plate 10.
• the ball consists of two electrically conductive halves 108 and 110 which are electrically separated by a central in ⁇ sulating strip 112. Electrical conductors 114 and 116 are each connected to one of the conductive halves, so that when the ball is nested in a passage 14 as shown in Figure 5, an electrical circuit is completed between the conductors by the conductive halves 108 and 110 and the heat exchanger plate. When the ball is not in contact with the crowns 12 on both sides of a passage 14, no electrical circuit is completed between the conductors 114 and 116.
• the die control circuit 46 is identical in structure and operation, for flattening both zones 24 and 26 and consequently will be described with reference to the structure of die control circuit 46 shown in Figure 6.
• This circuit includes input terminals 118 and 120 which supply power to control the operation of cylinder 42 ( Figure 2) , and input terminals 122 and 124 which supply power to a holding circuit. These input terminals may be connected to the same or separate power supplies, such as a battery power supply 140.
• the contact 134 is part of a holding relay including a holding relay coil 136 which is kept energized from terminal 122 across normally closed switches 56A and 56B after the contacts 138 have been initially closed by a brief closure of switch 54 to energize the coil 136 switches 56A and 56B open at the end of each die stroke.
• the heat exchanger plate 10 is moved between the upper and lower dies 34 and 36 by the driving wheels 48 and 50.
• the switches 56A and 56B are normally closed and the switch 54 is open.
• the holding relay coil 136 is normally energized with the contacts 134 and 138 closed.
• the detent switch 52 momentarily closes to energize holding relay coil 126 and close contacts 128.
• Current now flows from terminal 118 across contacts 128 and through coil 126, control solenoids 130A, 130B and contacts 134 back to terminal 120.
• the energization of solenoids 130A and 130B causes cylinders 42 and 44 to expand die piston rods 38 and 40 driving the dies 34 and 36 together.
• switches 56A and 56B are momentarily opened to deenergize holding relay coil 136. This opens contacts 134 and 138 causing the deenergization of control solenoids 130A, 130B and holding relay coil 126. upon deenergization of the control solenoids, the rods 38 and 40 are retracted to disengage the upper and lower dies 34 and 36 and reclose the switches 56A and 56B.
• a switch 54 is normally closed. The switch 54 is similar to switch 52 but is positioned to close during movement of the sheet and prior to closure of switch 52 to affect the next die stroke.
• Switch 54 is positioned appro ⁇ ximately 1/2 passage pitch different from switch 52 so that movement of the sheet alternately engages switches 52 and 54. This assures that switch 54 will close prior to the point where the passage in position for switch 52 to close and actuate the die stroke.
• the detent switch 52 is located closely adjacent the blades 58 and 80 at the entrant end of the die set and is spaced relative to these blades so that these entrant blades serve as locators for the re ⁇ maining blades in the die set,
• the slots 70-76 and 94-98 pro ⁇ gressively crush the crowns 12 received thereby while the intervening blades prevent the crushed crowns from expanding to block the passages 14.
• Each crown is subjected to a plurality of separate successive crushing operations until it reaches either the slot 76 or the slot 98. These final exit slots are so shallow that full crushing of the transition zones 24 and 26 is completed thereby. After these tran ⁇ sition zones are completely crushed, the remainder of the header zones 20 and 22 is crushed in the conventional manner.
• the blades in the faces of the upper and lower dies 34 and 36 will be formed to conform to the configuration of the passages 14 in the heat exchanger plate 10. Therefore, when the passages are wavy in configuration as shown in Figure 1, to enhance heat transfer, the blades will be similarly configured to conform therewith. Also, if the passages in one side of the plate vary in width from the passages on the opposite side, the width of the blades will also vary accordingly. Thus, as will be noted in Figure 3, the blades in the face of the lower die 36 are wider than those in the face. of the upper die 34.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Perforating, Stamping-Out Or Severing By Means Other Than Cutting (AREA)
• Heat-Exchange Devices With Radiators And Conduit Assemblies (AREA)

Priority Applications (5)

Applications Claiming Priority (2)

Publications (1)

Family

ID=22154179

Family Applications (1)

Country Status (5)

Cited By (1)

Citations (2)

Family Cites Families (7)

• 1980
  • 1980-01-28 DE DE8080901245T patent/DE3068482D1/de not_active Expired
  • 1980-01-28 WO PCT/US1980/000082 patent/WO1981002121A1/en active IP Right Grant
  • 1980-01-28 JP JP55501466A patent/JPH0217256B2/ja not_active Expired
  • 1980-01-28 EP EP19800901245 patent/EP0046750B1/en not_active Expired
  • 1980-08-22 CA CA000358989A patent/CA1148339A/en not_active Expired

Patent Citations (2)

Non-Patent Citations (1)

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