Abstract
In a method for producing a cooling plate, a workpiece in the form of a flat material blank with uniform material thickness is precisely centered in a tool. A substantially radially extending flat peripheral edge of the workpiece is formed by an outer punch of the tool, as the workpiece is held down by an inner punch of the tool and the outer punch is pressed against the peripheral edge to thereby reduce the material thickness of the peripheral edge. Pins are formed on a coolant-swept effective surface of a base of the workpiece by the inner punch through pressing in cooperation with pin forming openings of the tool as the outer punch is held down, such that the pins protrude approximately perpendicular beyond the base and are surrounded by the peripheral edge.
Claims
1. A method for producing a cooling plate, said method comprising: centering a workpiece in a tool, wherein the workpiece comprises a flat material blank with uniform material thickness; forming a substantially radially extending flat peripheral edge of the workpiece by pressing an outer punch of the tool against a peripheral edge of the workpiece to thereby reduce the material thickness of the peripheral edge of the workpiece, as the workpiece is held down by an inner punch of the tool; and forming pins on a coolant-swept effective surface of a base of the workpiece by the inner punch through pressing in cooperation with pin forming openings of the tool as the outer punch is held down against the peripheral edge of the workpiece, such that the pins protrude approximately perpendicular beyond the base and are surrounded by the radially extending flat peripheral edge.
2. The method of claim 1, wherein the cooling plate is made of copper, aluminum, or alloys thereof.
3. The method of claim 1, further comprising closing off by an ejection device at least some of the pin forming openings of the tool that are adjacent to the peripheral edge and offset to the peripheral edge by a pin length, when forming the peripheral edge by the outer punch.
4. The method of claim 1, further comprising calibrating the pins starting from their free ends.
5. The method of claim 4, further comprising flatly pressing or upsetting the free ends of the pins during calibration.
6. The method of claim 4, wherein the calibration is executed such that a diameter of the pins, starting from their free ends in a direction of a foot area of the base, becomes smaller to have a counter-conical configuration.
7. The method of claim 4, wherein the calibration is executed such that a diameter of the pins, starting from their free ends in a direction of a foot area of the base, becomes greater to have a conical configuration.
8. The method of claim 1, wherein the flat material blank has a tetragonal configuration.
9. The method of claim 1, wherein the flat material blank has a rectangular configuration.
10. The method of claim 1, further comprising forming the flat material blank from rolled or pressed material.
11. The method of claim 10, further comprising forming the flat material blank from rolled copper.
12. The method of claim 1, further comprising moving the outer punch and the inner punch toward the workpiece to form the substantially radially extending flat peripheral edge of the workpiece and the pins.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) Further details, features and advantages of the invention will become apparent from the following description of preferred exemplary embodiments without limiting character, with reference to the accompanying drawings. It is shown in:
(2) FIG. 1 a schematic sectional view of an example for use of a cooling plate according to the invention;
(3) FIGS. 2 to 7 schematic perspective partial sectional views to elucidate the process sequence in the production method of a cooling plate according to the invention;
(4) FIG. 8 and FIG. 9 enlarged cutaway views of individual pins of the cooling plate shown in FIG. 7, and lastly in
(5) FIGS. 10 to 12 schematic examples of further embodiments of the pins.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
(6) In the figures of the drawing, same or similar parts are designated by same reference numerals.
(7) FIG. 1 shows schematically an example for use of a cooling arrangement according to the invention, generally designated by 1. A cooling plate 3 is attached via the surface opposite to the pins on a component 2 to be cooled, such as an electrical or electronic component. As shown, the cooling plate 3 includes pins 4 on an effective surface 5 which is swept by coolant. In the illustrated example, a cover 7 is connected via a seal 6 in a fluid-tight manner to the substantially radially extending, flat peripheral edge U, which surrounds the pins 4, such that a gap 8 is formed between the cover 7 and the pins 4 of the cooling plate 3 and is flowed through by a coolant 9, such as cooling liquid or cooling fluid.
(8) The process sequence according to the invention for the production of a cooling plate of a material with very good thermal conductivity will be explained hi more detail with reference to FIGS. 2 to 7.
(9) FIG. 2 depicts schematically a partial sectional view of a tool W, which has many forming openings 20 at the bottom. An ejector device closes at least some of the forming openings 20 that are adjacent to the peripheral edge U. Indicated schematically at a distance to the tool W is a workpiece WS in the form of a flat material blank. This workpiece WS has a uniform or same material thickness in FIG. 2.
(10) As readily apparent from FIG. 3, the workpiece WS or the flat material blank 10 is placed precisely centered in the tool W resting on its bottom. As can be seen from FIG. 3, the flat material blank 10 is arranged in the tool W such that a predetermined distance A is maintained hi circumferential direction between the lateral boundaries of the tool W and the outer circumference of the flat material blank 10.
(11) FIG. 4 shows a schematic partial sectional view of a punch assembly, generally designated by 22. This punch assembly 22 includes at least one outer punch or peripheral edge punch 23 and an inner punch or pin punch 24. This punch assembly 22 is moved according to FIG. 5 toward the flat material blank 10 in such a way that the outer punch 23 forms by pressing the peripheral edge U with a reduced material thickness, as the workpiece WS or 10 is held down by the inner punch 24, As a result, a material overhang 11 is formed in the workpiece WS in relation to the formed peripheral edge U, when compared to FIG. 4. As is further apparent from FIGS. 4 and 5, parts of the ejection device 21 close off in preferred manner at least some of the pin forming openings 20 that are adjacent to the peripheral edge U. As a result, material of the workpiece WS can be effectively prevented from also entering the forming openings 20 during the pressing process for forming the peripheral edge U.
(12) The illustration according to FIG. 6 explains schematically the processing procedure, by which the inner punch 24 forms the pins 4 in cooperation with the pin forming openings 20 through pressing, as the outer punch 23 is held down. As can be seen from FIG. 6, the finished cooling plate 3 has a continuous base comprised of peripheral edge U and the remaining part of the cooling plate 3 with the pins 4. The material thickness of the base of the cooling plate 3 is substantially of same size as at the peripheral edge U.
(13) FIG. 7 illustrates a schematic perspective view of a cooling plate 3 with very closely lying pins 4 on the effective surface 5. The peripheral edge U surrounds the pins 4 and forms a common base with the foot region of the pins 4.
(14) FIG. 8 shows a schematic enlarged illustration of two pins, with the shape of which, as shown in FIGS. 5 and 6, being formed by the interaction of the inner punch 24 through a pressing operation in conjunction with the pin forming openings 20. FIG. 9 illustrates the cooling plate 3 with the pins 4 after undergoing calibration. As can be seen from FIGS. 8 and 9, the pins 4, 4 have, after formation during forming according to FIG. 6, free ends 12, which are slightly curved outward. During the calibration according to FIG. 9, these free ends 12 have been pressed flatly, or they may also be upset.
(15) Finally, with reference to FIGS. 10 to 12, further exemplary embodiments of configurations of the pins 4 are shown schematically.
(16) FIG. 10 shows cylindrically shaped pins 4′. FIG. 11 shows as an example a counter-conical configuration of pins 4″, which counter-conical configuration, however, extends only approximately over half the height of the respective pin 4″. With such a counter-conical configuration, starting from the free ends of the pins 4″, such a calibration is implemented by which the diameter of the pins 4″, starting from the free end 12, becomes smaller in direction of the foot area.
(17) FIG. 12 also illustrates an example of such a counter-conical construction of pins 4″. Here, the counter-conical configuration reaches almost to the foot region of the pins 4′″. Alternatively, the pins 4 can be formed as a whole conically or partly conically. This is realized by a corresponding calibration process. In such a case, starting from the free ends 12 of the pins 4, such a calibration is implemented by which the diameter of the pins 4, starting from the free end, increases in direction of the foot area.
(18) Of course, the invention is not limited to the illustrated exemplary embodiments, but numerous changes and modifications are possible, which the artisan will optionally apply, without departing from the spirit of the invention. In particular, the pins 4, 4′, 4″, 4′″ may, depending on the respective field of application, have configurations through calibration, which deviate from the illustrated exemplary embodiments, or may also include combinations of the exemplary embodiments shown in FIGS. 9 to 12. Even though the illustrated examples are based on a rectangular flat material blank 10, the latter may, of course, also be configured generally tetragonal or oval or the like, and a flat material blank of square shape may also be involved.
(19) Preferably, the flat material blank may be formed from rolled or pressed material, in particular from rolled copper. This involves a material with very good thermal conductivity.
