Cooling plate and method for manufacturing a cooling plate

Abstract

To provide a cooling plate improved in terms of functionality and production technology, and a rational method for producing the cooling plate.SOLUTION: A cooling plate 1 for the battery cooling of a motor vehicle comprises: one plate body 2 including two plate elements 3, 4 joined together by soldering, at least one cooling channel 5 for the passage of a cooling fluid, and one stiffening molding 6. The cooling channel 5 and the stiffening molding 6 are initially formed together continuously during the manufacture of the plate body 2 by forming a channel in a plate element 3, 4 by internal high pressure forming. In the soldering process, a channel portion 7 of the channel 11 is sealed in a fluid-tight manner by a closing element 8 in the form of a press soldering joint 9. This separates the channel 11 into the cooling channel 5 and the stiffening molding 6.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a cooling plate for cooling a battery, particularly for cooling a battery of a motor vehicle, and a method for manufacturing the cooling plate.

Background Art

[0002] In electric or hybrid motor vehicles, high-voltage battery systems are used. In order to ensure the driving range, driving performance, charging performance and service life of an electrically driven vehicle, a predetermined thermal management of the battery is necessary. The battery is sensitive to different temperature distributions, which can cause overheating and premature deterioration. In order to keep the battery within an optimal temperature range, a cooling device is used to discharge the excessive waste heat generated during the operation of the battery from the battery and ensure that the battery is temperature-controlled to a uniform temperature level.

[0003] To cool a battery or a battery module, a cooling plate is used which is arranged above, beside and / or below the battery and directly or indirectly contacts the battery or the battery module. The cooling fluid flows through the cooling plate. Such a cooling plate usually consists of a plate body assembled from two plate elements that define one or more cooling channels therebetween. Usually, the cooling plate is manufactured from a light metal sheet, particularly an aluminum sheet.

[0004] According to German Patent Specification No. 102008059955, a method for manufacturing a cooling plate in which a cooling plate and cooling channels are integrated is part of the prior art. The cooling plate comprises a plate body composed of two plate elements having connections for the cooling fluid. In one of the plate elements of the cooling plate, the cooling channels are formed by non-cutting forming techniques. The plate element provided with the cooling channels is closed by a second flat plate element.

[0005] Cooling plates configured similarly are described in German Patent Application Publication No. 102011106662 and German Patent Application Publication No. 102011107607, in which the cooling plate or the plate body is provided with reinforcing elements in the form of a rigid molded portion or a coolant-free cavity, thereby providing additional reinforcement to the cooling plate. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] German Patent No. 102008059955 [Patent Document 2] German Patent Application Publication No. 102011106662 [Patent Document 3] German Patent Application Publication No. 102011107607 Specification [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] Based on prior art, the fundamental problem of the present invention is to provide a cooling plate that is functionally and technically improved in terms of manufacturing technology, and to present a rational method for manufacturing a cooling plate. [Means for solving the problem]

[0008] The solution to the physical part of the problem lies in the cooling plate according to the features of claim 1.

[0009] The method of the problem is solved by the method of claim 6.

[0010] Preferred embodiments and variations of the present invention are subject to the dependent claims.

[0011] The cooling plate comprises a plate body composed of two plate elements. Cooling fluid is supplied and discharged via connecting pipes. The connecting pipes are materially joined to the plate body or its plate elements. The plate elements are, in particular, channel plates and base plates that are integrated into and joined to each other in a plate stack to form the plate body. The plate elements are made of light metal or light metal alloy, particularly aluminum alloy. At least one of the plate elements of the cooling plate's plate body has a channel structure for allowing the cooling fluid to pass through. The plate elements are materially joined by press brazing. The brazing process is performed in a forming brazing die. Thus, the plate stack composed of both plate elements is clamped and pressed against each other in the forming brazing die, and the melting temperature of the brazing material applied between the plate elements exceeds the melting temperature. of When heated to a certain temperature, the brazing material melts and changes into a liquid phase. After the brazing material solidifies, a material bond is formed between the plate elements at the adjacent joint surfaces.

[0012] To form one or more channels in at least one of the plate elements, the plate elements are clamped within a forming brazing die, and the intermediate space between the plate elements is subjected to internal pressure. For this purpose, a working medium is introduced into the intermediate space, and a channel structure having at least one or more channels is formed by internal high-pressure technology.

[0013] The cooling plate according to the present invention for battery cooling comprises a plate body composed of two plate elements joined to each other by brazing technology. The plate body comprises a channel structure having at least one cooling channel for the passage of a cooling fluid and at least one reinforcing molded portion. The reinforcing molded portion is used to reinforce the plate body and improve the dimensional stability of the cooling plate. High dimensional stability ensures good contact of the cooling plate with the battery module, which is advantageous for thermal management. The high dimensional stability of the cooling plate also works to its advantage when subjected to impact loads, as well as during handling in the battery placement and cooling system assembly processes.

[0014] According to the present invention, the channel portion between the cooling channel and the reinforcing molded portion is fluid-tightly closed by a closing element.

[0015] The reinforcing molded portion is preferably composed of a groove-shaped or bead-shaped molded portion within at least one of the plate elements. The reinforcing molded portion is formed together with the cooling channel during molding using internal high-pressure technology. A closing element separates the channel formed between the plate elements into the cooling channel and the reinforcing molded portion. It will be done In this way, a cooling plate is provided that is functionally and technologically improved. The manufacture of the cooling plate, in particular a reinforcing structure having reinforcing molded parts within the cooling plate, is rational, economical, and space-saving. The arrangement and geometry of the reinforcing molded parts, especially the multiple reinforcing molded parts constituting the reinforcing structure, ensure high dimensional stability of the cooling plate with high rigidity suitable for the component against the weight of the battery or battery module, as well as the loads and forces acting during operation.

[0016] The coolant does not flow through the reinforced molded section. The coolant flow is fluid-tightly separated by a closure element. Advantageously, one or more openings are provided within the reinforced molded section. These are functional openings, which either allow ventilation of the reinforced molded section or are used for fixing, for example, to a base plate.

[0017] The method for manufacturing a cooling plate is: - A step of providing a plate laminate consisting of at least two plate elements made of a metal material with a brazing material placed between them, - The step of inserting a plate stack into a heated molding brazing die having a lower die and an upper die, - The step of closing the mold, in which the lower mold and upper mold are moved relative to each other, - The steps include closing the molding brazing die and clamping the plate stack between the lower and upper molds, - A step of heating the plate laminate; - A step of applying an internal pressure to the intermediate space between the plate elements of the plate laminate by introducing a working medium, and forming channels in at least one of the plate elements; - A step of melting the brazing material between the plate elements and joining the plate elements by brazing technology at the contacting joint surfaces, - A step of forming a closing element, by which the channels are separated into cooling channels and reinforcing molded parts; - A step of opening the molding brazing die and taking out the cooling plate from the molding brazing die; comprises.

[0018] The closing element is formed by a press brazing joint in the brazing process. Here, the closing element is formed within the channel portion of the channels formed by internal high-pressure technology. A plurality of reinforcing molded parts can be formed. Correspondingly, a plurality of channel portions are each closed by a closing element, whereby each one reinforcing molded part is separated from one or more cooling channels.

[0019] Before the fluid-tight separation of the cooling channels and the reinforcing molded parts, they are connected via the channel portion. The channel portion is part of the channels formed by hydroforming technology. The channel portion can be formed geometrically smaller than the cooling channels and / or the reinforcing molded parts. In particular, the channel portion can have a smaller cross-section than the cooling channels or the reinforcing molded parts. The channel portion is fluid-tightly closed by a closing element.

[0020] Preferably, an opening is formed in the reinforcing molded part, whereby the reinforcing molded part is vented. The opening can be formed within the molding brazing die. Preferably, one or more openings within the reinforcing molded part are formed following the manufacture of the cooling plate outside the molding brazing die.

[0021] The forming brazing mold is heated to the mold temperature when both the internal high-pressure forming process and the joining process by brazing technology are carried out. In particular, the mold temperature is 540°C to 670°C, and particularly preferably, the mold temperature is 550°C to 640°C.

[0022] Particularly preferably, a plurality of reinforcing forming parts, particularly reinforcing beads, extend parallel to one cooling channel, one cooling channel portion, one cooling channel structure or a plurality of cooling channels.

[0023] When forming the brazed joint between the plate elements, the channel portion is closed during the brazing process. In this brazing process, the punch in the forming brazing mold presses to close the channel portion, whereby this channel portion is also brazed. This provides a reinforcing forming part having a hollow chamber that is separated from the cooling channel and through which the cooling fluid does not flow during operation but increases the component rigidity.

[0024] An advantageous formation of the method according to the invention contemplates that the closing process of the forming brazing mold is interrupted before reaching the closed position. The upper mold and the lower mold are positioned spaced apart from each other at this holding position when inserting the plate laminate. The holding position is held for a holding time. Here, the plate laminate located on the lower mold is heated. After the holding time, the closing movement is continued, the forming brazing mold is closed, and the plate laminate is clamped between the lower mold and the upper mold. Clamped in the forming brazing mold, further heating of the plate laminate is carried out to the brazing temperature.

[0025] The present invention will be described in detail below with reference to the drawings.

Brief Description of the Drawings

[0026] [Figure 1] Perspective view of the cooling plate according to the present invention

Embodiments for Carrying out the Invention

[0027] Cooling plate 1 is used for battery cooling, particularly for vehicle batteries in automobiles.

[0028] The cooling plate 1 comprises a plate body 2 composed of two plate elements 3 and 4. In the image plane, the front plate element 3 is a channel plate having a channel structure with at least one cooling channel 5. The rear plate element 4 shown in the figure is typically a completely or nearly completely flat base plate.

[0029] The two plate elements 3 and 4 are positioned flat vertically to form the plate body 2. The adjacent surfaces of the plate elements 3 and 4 are coated with brazing material, either entirely or regionally. In particular, the brazing material is pre-applied to one of the plate elements 3 and 4 in the form of a plating brazing layer.

[0030] The adjacent surfaces of plate elements 3 and 4 are joined to each other, either entirely or regionally. A connecting pipe for cooling fluid, not shown in Figure 1, is connected to plate body 2. The connecting pipe is used to supply and discharge the cooling fluid.

[0031] The plate body 2 comprises a reinforcing structure having one, preferably multiple, reinforcing molded portions 6. The reinforcing molded portions 6 are formed in particular in the form of reinforcing beads. Molding part The 6 and the cooling channel 5 were initially connected via a channel portion 7. The channel portion 7 between the cooling channel 5 and the reinforcing molded portion 6 is fluid-tightly closed by a closure element 8. The closure element 8 is composed of a press-brazed joint 9.

[0032] The reinforcing molded section 6 is provided with one or more openings 10. The openings 10 are used for ventilation of the reinforcing molded section 6 or for fixing to or to functional components, and are formed after the manufacture of the cooling plate 1 or plate body 2.

[0033] The cooling channel 5, reinforcing molded portion 6, channel portion 7, and closing element 8 that fluidly closes the channel portion 7 are formed during the manufacturing of the cooling plate 1 or plate body 2.

[0034] To manufacture the cooling plate 1, a plate laminate is provided consisting of at least two initially flat plate elements 3 and 4 made of aluminum alloy. A brazing material is applied between the plate elements 3 and 4, and the brazing material is applied to at least one of the plate elements 3 and 4 in the form of a plating brazing layer.

[0035] The plate stack is inserted into a heated molding brazing die.

[0036] A forming brazing die comprises a lower die and an upper die. These dies move relative to each other during the closing motion of the forming brazing die. In particular, the upper die is lowered onto the lower die. The closing motion is interrupted to heat the plate stack. The upper and lower dies are positioned with a small gap between them. The gap is several centimeters. The plate stack is movably positioned on the lower die and preheated. After this heating stage, which can be longer than 5 seconds and preferably less than 1 minute, particularly 10 to 30 seconds, the forming brazing die is completely closed by the lowering of the upper die onto the lower die. The plate stack is housed and clamped between the lower and upper dies. The plate stack is in surface contact with the lower and upper dies and is further heated within the forming brazing die. The forming brazing die is heated to a die temperature in which both the forming process and the joining process by brazing technique are performed. In particular, the die temperature is 54°C to 670°C, and particularly advantageously, the die temperature is 550°C to 640°C.

[0037] The intermediate space between plate elements 3 and 4 of the plate stack is subjected to internal pressure. The intermediate space is the region between adjacent plate elements, and the gap between the plate elements does not necessarily have to be located within the intermediate space region. The internal pressure is applied to the intermediate space by introducing a working medium, particularly nitrogen, into the intermediate space. Here, the channel 11 is formed by forming at least one plate element region into a channel cavity within one or both contact surfaces of the forming brazing die using internal pressure techniques. The working medium is preferably supplied via one of the connecting tubes of the plate stack or via an external connecting adapter.

[0038] The brazing material between plate elements 3 and 4 is melted due to the mold temperature of the brazing die. The plate elements 3 and 4 and the connecting pipe, which is positioned by the joint, are joined together by brazing technology.

[0039] During the formation of the joint between plate elements 3 and 4 using press brazing technology, the channel portion 7 of channel 11 is closed by a closing element 8 in the form of a press brazed joint 9. This separates channel 11, which is continuously formed by internal high-pressure technology, into a cooling channel 5 and a reinforcing molded portion 6. The cooling channel 5 and the reinforcing molded portion 6 were connected via channel portion 7 during internal high-pressure molding. These connections or channel portions 2 are closed by the closing element 8 during the brazing process. Therefore, the punch in the molding brazing die but By pressing and closing the channel portion 7, this channel portion is also brazed, thereby the press-brazed joint 9 becomes the channel portion minutes It is formed within 7. In this way, one or more cooling channels 5 are provided that are set and configured to allow the cooling fluid to pass through. Furthermore, a number of reinforcing molded sections 6 are provided through which the cooling fluid does not pass during operation. The reinforcing molded sections 6 enhance dimensional stability and part rigidity.

[0040] The forming brazing die is opened after the forming brazing process is complete, and the lower and upper dies are moved relative to each other and separated. The joined hot plate body 2 or cooling plate 1 can be removed from the forming brazing die after it has been opened. Before removal, the cooling plate 1 can be held and cooled within the forming brazing die. Cooling is preferably carried out to below the melting temperature of the brazing material.

[0041] The plate stack is clamped between the lower and upper molds during the manufacture of the cooling plate. During the molding and formation of the channel 11 by internal pressure technology, and during the separation of the fluid-tightness of the channel 11 from the cooling channel 5 and the reinforcing molded portion 6, particularly the reinforcing bead, the plate stack is sealed annularly along adjacent peripheral regions and / or adjacent to the channel cavity. The seal can be achieved or assisted by pressurizing elements provided in the lower and / or upper molds. Such pressurizing elements are optional and may also be provided in the region of the connecting tube. The pressurizing elements can be formed by corresponding contour formation within the molded portions of the lower and / or upper molds, for example, by a seal bead. The seal elements can be provided annularly along adjacent peripheral regions of the upper and / or lower molds. The seal elements may also be provided adjacent to the channel cavity. The seal elements ensure a particularly advantageous molding process, especially that this molding process takes place in the region of the channel cavity. In this way, high dimensional accuracy and molding accuracy are guaranteed. While this application relates to the invention described in the claims, it may also encompass the following other embodiments. 1. A cooling plate (1) for cooling a battery has a plate body (2) which is composed of two plate elements (3,4) joined together by brazing, and which has at least one cooling channel (5) for passing a cooling fluid and one reinforcing molded part (6), A cooling plate (1) characterized in that the channel portion (7) between the cooling channel (5) and the reinforcing molded portion (6) is fluid-tightly closed by a closing element (8). 2. The cooling plate according to claim 1, characterized in that the closing element (8) is composed of a joint, in particular a press-brazed joint (9). 3. The cooling plate according to claim 1 or 2, characterized in that the reinforcing molded portion (6) is composed of groove-shaped or bead-shaped molded portions within at least one of the plate elements (3, 4). 4. A cooling plate according to any one of the above 1 to 3, characterized in that the reinforcing molded portion (6) is provided with an opening (10). 5. A cooling plate according to any one of claims 1 to 4 above, characterized in that the cooling channel (5) and the reinforcing molded portion (6) are formed by internal high-pressure technology. 6. In a method for manufacturing a cooling plate (1), - A plate laminate consisting of at least two plate elements (3,4) made of a metal material with a brazing material placed between them, - The step of inserting a plate stack into a heated molding brazing die having a lower die and an upper die, - The steps include moving the lower and upper molds relative to each other, closing the mold, - The steps include closing the molding brazing die and clamping the plate stack between the lower and upper molds, - The step of heating the plate stack, - The steps include: applying internal pressure to the intermediate space between the plate elements (3,4) of the plate stack by introducing a working medium, thereby forming a channel (11) in at least one of the plate elements (3,4); - A step of melting brazing material between plate elements (3,4) and joining the plate elements (3,4) at the contacting joint surfaces by brazing technique, - A closing element (8) is formed, and this closing element separates the channel (11) into a cooling channel (5) and a reinforcing molded portion (6). - The steps include opening the molding brazing die and removing the cooling plate (1) from the molding brazing die, A method characterized by having the following: 7. The method according to the above-mentioned paragraph, characterized in that the closing element (8) is formed by a press-brazed joint (9) in a brazing process. 8. The method according to 6 or 7, characterized in that the closing element (8) is formed within the channel portion (7) of the channel (11). 9. The method according to any one of 6 to 8 above, characterized in that an opening (10) is formed in the reinforcing molded portion (6). 10. The method according to any one of the above 6 to 9, characterized in that the molding brazing die is heated to a die temperature of 540°C to 670°C, particularly 550°C to 640°C. 11. The method according to any one of 6 to 10 above, characterized in that the closing process of the molding brazing die is interrupted for a holding time before reaching the closed position, the upper and lower dies are positioned spaced apart from each other when the plate stack is inserted, and after the holding time the molding brazing die is closed and the plate stack is clamped between the lower and upper dies. [Explanation of symbols]

[0042] 1 Cooling plate 2 Plate bodies 3 Plate elements 4 plate elements 5 Cooling Channels 6. Reinforced molded section 7 Channel Section 8 Closure elements 9 Press brazed joint 10 aperture 11 channels

Claims

1. A cooling plate (1) for cooling a battery has a plate body (2) which is composed of two plate elements (3, 4) joined together by brazing, and which has at least one cooling channel (5) for passing a cooling fluid and one reinforcing molded part (6), A cooling plate (1) characterized in that the channel portion (7) between the cooling channel (5) and the reinforcing molded portion (6) of a channel (11) continuously formed by internal high-pressure molding is fluid-tightly closed by a closing element (8) in the form of a press-brazed joint (9), thereby separating the channel (11) into the cooling channel (5) and the reinforcing molded portion (6).

2. The cooling plate according to claim 1, characterized in that the reinforcing molded portion (6) is composed of groove-shaped or bead-shaped molded portions within at least one of the plate elements (3, 4).

3. The cooling plate according to claim 1, characterized in that the reinforcing molded portion (6) is provided with an opening (10).

4. In a method for manufacturing a cooling plate (1), - A plate laminate comprising at least two plate elements (3, 4) made of a metal material with a brazing material placed between them, - The step of inserting a plate stack into a heated molding brazing die having a lower die and an upper die, - The steps include moving the lower and upper molds relative to each other, closing the mold, - The steps include closing the molding brazing die and clamping the plate stack between the lower and upper molds, - A step of heating the plate stack, - The step of introducing a working medium to apply internal pressure to the intermediate space between the plate elements (3, 4) of the plate stack, thereby forming a channel (11) in at least one of the plate elements (3, 4), - A step of melting the brazing material between the plate elements (3, 4) and joining the plate elements (3, 4) at the contacting joint surfaces by brazing technology, - A closing element (8) in the form of a press-brazed joint (9) is formed within the channel portion (7) between the cooling channel (5) and the reinforcing molded portion (6) of the channel (11), and this closing element separates the channel (11) into the cooling channel (5) and the reinforcing molded portion (6). - The steps include opening the molding brazing die and removing the cooling plate (1) from the molding brazing die, A method characterized by having the following:

5. The method according to claim 4, characterized in that an opening (10) is formed in the reinforcing molded portion (6).

6. The method according to claim 4, characterized in that the molding brazing die is heated to a die temperature of 540°C to 670°C, particularly 550°C to 640°C.

7. The method according to claim 4, characterized in that the closing process of the molding brazing die is interrupted for a holding time before reaching the closed position, the upper and lower dies are positioned spaced apart from each other when the plate stack is inserted, and after the holding time the molding brazing die is closed and the plate stack is clamped between the lower and upper dies.

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