DE102020200649A1 - Partial forming for the production of heat sinks - Google Patents

Abstract

A method is disclosed for producing components (100), in particular pin heat sinks or ribbed heat sinks, at least one blank (40) being provided and inserted into a receptacle (23) of at least one mold section (21) of a first tool half (20), a second tool half (30), comprising at least one pressure disk (31), is partially pressed by tumble forming or rotary forging to form the first tool half (20), the at least one blank (40) under pressure through the pressure disk (31) through the receptacle (23) the at least one mold section (21) of the first tool half (20) is pressed into it. A device (10) is also disclosed.

Description

The invention relates to a method for producing heat sinks, in particular pin heat sinks or rib heat sinks, and a device.

With the increasing spread of electrically powered vehicles, the use of electric motors with appropriate control is increasing. The control of electric motors is usually designed in the form of power electronics. When the power electronics are in operation, heat loss occurs which has to be dissipated. In particular, power semiconductors of the power electronics can heat up during operation, whereby they only have a limited temperature stability and thus require cooling.

Different cooling concepts are already known which enable liquid-cooled or air-cooled temperature control of electronic components. Pin heat sinks or so-called PinFin heat sinks can be used for particularly efficient cooling. Such pin heat sinks can be produced, for example, by machining a solid material or by joining various individual parts. Further manufacturing processes for pin heat sinks can be implemented by sintering or by casting.

The known manufacturing processes for pin heat sinks are usually time-consuming. Machining manufacturing processes have a large amount of waste. A cost-efficient production of pin heat sinks in large numbers is therefore not possible.

The invention is based on the object of creating a method and a device for the cost-efficient production of heat sinks. This object is achieved by the features specified in claim 1. Further advantageous refinements of the invention are described in the subclaims.

According to one aspect of the invention, a method for producing heat sinks, in particular pin heat sinks or rib heat sinks, is provided.

In one step, at least one blank is provided and inserted into a receptacle of at least one mold section of a first tool half.

A second tool half, which has at least one thrust washer, is partially pressed to form the first tool half by tumbling or rotary forging. A tumbling movement with a feed rate in the direction of the first tool half can preferably be provided.

The at least one blank is then pressed under the action of pressure through the pressure disk through the receptacle into the at least one mold section of the first tool half.

By pressing the blank into the mold section, the blank is formed into a component. In a further step, the component can be removed from the mold section. For this purpose, release pins arranged in the first tool half can be provided, for example.

The method can preferably be implemented as a partial eccentric deformation by means of rotary forging or wobble deformation of non-rotationally symmetrical components. In this case, the mold section can have a cavity which has the shape of a component to be produced.

The method can be used, for example, to produce pin heat sinks for power electronics. However, the method is not limited to the production of heat sinks. The process is suitable for the production of complex components of all types with a high degree of deformation required.

The mold section is preferably arranged outside an axis of rotation of the second tool half or eccentrically, whereby the pressure disk can act gradually with increasing feed on the at least one blank and mold the blank into the cavity of the at least one mold section.

Eccentric rotary forging or wobble forming can enable the combined use of partial forming and vibration presses, which results in a particularly high degree of forming. In this way, complex shapes, such as PinFin structures or rib structures, can be designed particularly efficiently.

The method can preferably take place in one stroke, the second tool half being pressed against the at least one blank while rotating or tumbling. The blank is locked in place in the receptacle of the first tool half and can thus become flowable through eccentric rotary forging or tumble forming in such a way that the cavity of the mold section is filled with the material of the blank.

The mold halves can be compressed pneumatically, mechanically or hydraulically.

According to one exemplary embodiment, the at least one blank is designed as a sheet metal or a solid material and is inserted into the receptacle of the at least one shaped section. As a result, the at least one blank can be provided in a particularly cost-effective manner.

The at least one blank can consist of one material or be formed from several metallic materials. For example, the blank can consist of copper, a steel or a metal alloy such as AlSiC.

Furthermore, with the help of a suitable multi-part blank, hybrid forming for joining two metals, such as copper and aluminum, can be implemented.

The at least one component can be produced in a particularly flexible manner if the at least one blank is pressed into the at least one mold section of the first tool half at room temperature or under the influence of temperature by the action of pressure from the at least one pressure washer. Thus, the deformation can take place as a cold deformation or as a deformation with a heating temperature adapted to the material.

According to a further embodiment, the at least one blank is pressed into the at least one mold section of the first tool half with the addition of a solid and / or liquid lubricant by the action of pressure from the at least one pressure disk. By adding a lubricant, the first tool half and the second tool half can be protected during manufacture and the manufacturing device can be made more reliable.

Furthermore, a film can be pressed with the blank during the forming process in order to facilitate removal of the component from the mold section. Depending on the configuration of the molded section, a surface structure can be applied to the component. For example, a higher surface roughness can be applied to a component designed as a heat sink in order to optimize the cooling effect.

According to a further exemplary embodiment, several blanks are inserted into receptacles of several mold sections of the first tool half and pressed into the mold sections by a pressure disk or several pressure disks arranged concentrically on the second tool half. As a result of this measure, several blanks can be formed into several components at the same time in one stroke.

The respective mold sections can be configured identically or differently, as a result of which several different components can be produced within one work step.

The method can also be used to shape blanks made of materials that are difficult to deform into components if the at least one blank is preformed in at least one first mold section by a partially deforming movement of the pressure plate, in the preformed state from the at least one first mold section, in at least one second mold section is used and is finished formed by the pressure disc to at least one component. In this way, as an alternative to a complete filling of the structure or the cavity of a mold section, a multi-stage deformation for the production of the component can be realized in one deformation step. The blank is preformed in an intermediate step and formed into a finished structure or final geometry in at least one further molding step.

According to a further aspect of the invention, an apparatus for producing components such as heat sinks is provided. The device has a first tool half with at least one mold section, the at least one mold section having a receptacle for receiving a blank in a stationary manner. Furthermore, the device has a second tool half with at least one pressure disk, which can be driven in a partially deforming manner and can be pressed against the first tool half, the at least one mold section being arranged eccentrically.

By means of such a device, the at least one blank can be reshaped into components in a resource-efficient manner. The loss of material can be minimized compared to machining processes.

Since the at least one component can be produced in one stroke of the second tool half, the process time can be reduced.

Because of the minimized loss of material and the minimized manufacturing time, the at least one component can be manufactured particularly cost-effectively.

Furthermore, the eccentric deformation of the blank by wobbling or angular rotation of the second tool half enables the formation of a component without porosity, so that a Component with improved mechanical properties can be produced.

The at least one mold section has one or more cavities which determine a shape of the component. The component can be designed, for example, as a pin heat sink. The respective pins or PinFins of the heat sink can be formed oval, angular, hollow, round, star-shaped and the like, depending on the configuration of the cavity of the molded section.

According to one embodiment, the first tool half has a plurality of eccentrically arranged mold sections, the mold sections being distributed concentrically, linearly, cross-shaped or star-shaped on the first mold half. As a result, the mold sections can be distributed symmetrically on the first tool half. For example, four mold sections with an angular offset of 90 ° to one another or six mold sections with an angular offset of 60 ° to one another can be arranged on the first mold half. This measure enables the number of components that can be produced per stroke to be set.

The second tool half can be designed in a technically particularly simple manner if it has a pressure disk which is set up to reshape a plurality of blanks inserted in receptacles of a plurality of mold sections. The thrust washer can, for example, be conical or flat. In particular, the shape and size of the pressure disk can be adapted to an arrangement of the mold sections on the first tool half.

According to a further embodiment, the second tool half has at least two ring-shaped and concentrically arranged pressure disks which are set up to reshape a plurality of blanks inserted in receptacles of a plurality of mold sections. This measure enables the pressure disks to act specifically on the blanks. The pressure disks can preferably run above the mold sections in order to reshape the blanks in a concentrated manner into the cavities of the mold sections. Depending on the configuration of the device, the pressure disks can protrude into the receptacles of the mold sections in order to introduce the blanks into the cavities without leaving any residue.

The at least one pressure disk and in particular the second tool half preferably perform a tumbling movement with a circumferential direction (circular movement, spiral movement, linear movement, multi-blade curve movement). The first half of the tool can perform the feed movement (wobble forming).

The first and the second tool half can alternatively also rotate, preferably synchronously, so that the first tool half and the second tool half come together or are pressed onto one another at the same position after each rotation of the first tool half. Due to the angular position of the upper tool or the second tool half, the pressing takes place partially, and the combination with the rotary movement of the first tool half regularly results in loads and relief of the blank, which significantly improves the flowability of the material of the blank (rotary forging).

• 1 eine schematische Vorrichtung zum Herstellen von Kühlkörpern gemäß einer ersten Ausführungsform,
• 2A, 2B Schnittdarstellungen einer Detailansicht einer Vorrichtung zum Herstellen von Kühlkörpern gemäß einer zweiten Ausführungsform,
• 3A, 3B, 3C Draufsichten auf eine erste Werkzeughälfte,
• 4 eine perspektivische Darstellung eines durch eine erfindungsgemäße Vorrichtung hergestellten Bauteils, und
• 5 eine Schnittdarstellung aus 2B zum Veranschaulichen eines mehrstufigen Verfahrens zum Herstellen von Kühlkörpern.

Exemplary embodiments of the invention are explained in greater detail below with reference to the drawings. Show it:

• 1 a schematic device for producing heat sinks according to a first embodiment,
• 2A , 2 B Sectional representations of a detailed view of a device for producing heat sinks according to a second embodiment,
• 3A , 3B , 3C Plan views of a first mold half,
• 4th a perspective view of a component produced by a device according to the invention, and
• 5 a sectional view 2 B to illustrate a multi-step process for manufacturing heat sinks.

In the figures, the same structural elements have the same reference numbers in each case.

the 1 shows a schematic device 10 for the manufacture of components 100 according to a first embodiment. In the figures the component is 100 configured as a heat sink, which is shown in FIG 4th is illustrated.

The device 10 has a first tool half 20th and a second tool half 30th on. The first half of the tool 20th is around an axis of rotation A. rotatably mounted. The second half of the tool 30th is also around the axis of rotation A. rotatably mounted, the second tool half 30th a synchronous rotational movement with angular offset W. performs. Such an arrangement of the tool halves 20th , 30th the device can be used to perform an eccentric rotary deformation.

The first half of the tool 20th is exemplarily opposite to a direction of rotation R. the second half of the tool 30th turned. The first Tool half 20th is in contrast to the second half of the tool 30th does not tumble rotates.

The second half of the tool 30th has a thrust washer 31 on. The thrust washer 31 is to the mold section 21 the first half of the tool 20th arranged directed and can with a feed rate V against the first half of the tool 20th be pressed. The thrust washer 31 is, for example, conically shaped and has a lateral surface 32 on, which can be used to exert a compressive force.

the 2A and 2 B show sectional views of a detailed view of a device 10 for the production of heat sinks 100 according to a second embodiment. The detailed view illustrates the first half of the tool 20th and the second half of the tool 30th . In contrast to the in 1 illustrated embodiment has the second tool half 30th two ring-shaped pressure washers 33 , 34 which are arranged concentrically. A first thrust washer 33 is arranged radially on the inside. A second thrust washer 34 is arranged radially on the outside.

The first half of the tool 20th has multiple mold sections 21 on which each has a cavity 22nd exhibit. Towards the second half of the tool 30th extends from each mold section 21 a recording 23 for holding a blank 40 , 41 .

The recording is carried out, for example, by two opposing webs, which are used for stationary positioning or receiving the blank 40 , 41 serve.

The blank 40 can consist of a metallic material. In the exemplary embodiment shown, the blank is 40 , 41 designed as a cube made of copper.

The thrust washers 33 , 34 the second half of the tool 30th are dimensioned so that they fit into the recordings 23 protrude and thus the blank 40 , 41 completely into the cavity 22nd can press.

The cavities 22nd are used to form components 100 shaped, which are designed as a pin heat sink.

Due to the partially deforming movement of the second half of the tool 30th and the thrust washers 33 , 34 there is a step-by-step or successive reshaping of the blanks 40 , 41 .

the 3A , 3B and 3C show schematic top views of the first tool halves 20th according to further exemplary embodiments. In the 3A shows the tool half 20th for example, shaped sections arranged in a cross shape 21 on. The respective recordings 23 and cavities 22nd are not shown for the sake of clarity.

the 3B shows a first tool half 20th with star-shaped distributed shaped sections 21 . In the 3C are the mold sections 21 arranged concentrically and are preferably corresponding to the extent of the concentric pressure surfaces 33 , 34 the second half of the tool 30th positioned.

the 4th shows a perspective view of a device according to the invention 10 manufactured component 100 , which after pressing into the cavity 22nd was demolded. The component 100 is shaped as a pin heat sink or as a so-called PinFin structure. To this end, the component 100 an extensive base section 110 on. From the basic section 110 extends a variety of pins 120 or pins. The pencils 120 stand perpendicular to the base section 110 .

In the 5 FIG. 3 is a sectional view from FIG 2 B to illustrate a multi-step process for manufacturing heat sinks 100 shown. During a press stroke in the direction of the feed V the “tumbling” pressing process takes place in all mold sections at the same time 21 instead of.

In the illustrated embodiment, there are two different types of mold sections 21 provided with differently shaped cavities. A first type of mold section 21 ' with a first cavity is designed in such a way that a blank 40 into a preformed blank 42 due to the radially inner pressure surface 33 is reshaped.

A second mold section 21 " has a second cavity 22 " on which the preformed blank 42 can be inserted and through the radially outer pressure surface 34 to a heat sink or finished component 100 is malleable.

Several blanks can be used 40 in a first stroke of the second mold half 30th through the first mold section 21 ' into several preformed blanks 42 be shaped. After the second half of the tool has been spaced apart 30th from the first half of the tool 20th can use the preformed blanks 42 by release pins 50 demolded and into the second mold sections 21 " can be used.

In a second pressing process, they can be used in the second mold sections 21 " inserted preformed blanks 42 final to components 100 reshaped and then by release pins 50 be demolded.

Through the device 10 For example, the first or the pre-forming step and the second or the final forming step can be carried out simultaneously. This process can also be done with a one-piece or conically shaped pressure surface 31 implemented.

List of reference symbols

100

Component

110

Basic section

120

pencils

10

contraption

20th

first mold half

21

Mold section

21 '

first mold section

21 "

second mold section

22nd

cavity

22 '

first cavity

22 "

second cavity

23

recording

30th

second mold half

31

conically shaped pressure surface

32

Outer surface of the conically shaped pressure surface

33

radially inner pressure surface

34

radially outer pressure surface

40

radially inner blank

41

radially outer blank

42

preformed blank

50

Release pin

A.

Axis of rotation

R.

Direction of rotation of the second half of the tool

V

Feed

W.

Angular offset of the rotating movement

Claims (10)

Method for producing components (100), in particular pin heat sinks or rib heat sinks, wherein - at least one blank (40) is provided and inserted into a receptacle (23) of at least one mold section (21) of a first tool half (20), - A second tool half (30), having at least one pressure disk (31) in the direction of the first tool half (20), is partially pressed to the first tool half (20) by tumbling or rotary forging, - The at least one blank (40) is pressed under the action of pressure through the pressure disc (31) through the receptacle (23) into the at least one mold section (21) of the first tool half (20). Procedure according to Claim 1 wherein the at least one blank (40) is designed as a sheet metal or a solid material and is inserted into the receptacle (23) of the at least one molded section (21). Procedure according to Claim 1 or 2 wherein the at least one blank (40) is pressed into the at least one mold section (21) of the first tool half (20) at room temperature or under the action of temperature by the action of pressure from the at least one pressure disk (31). Method according to one of the Claims 1 until 3 , wherein several blanks (40, 41) are inserted into receptacles (23) of several mold sections (21) of the first tool half (20) and are supported by a pressure disk (31) or several pressure disks (33, 34) arranged concentrically on the second tool half (30) ) are pressed into the mold sections (21). Method according to one of the Claims 1 until 4th , wherein the at least one blank (40) is preformed by a partially deforming movement of the thrust washer (31) in at least one first mold section (21 '), demolded in the preformed state from the at least one first mold section (21'), in at least one second mold section (21 ") is inserted and finished-formed into at least one component (100) by the thrust washer (31). Device (10) for producing components (100), for example heat sinks, having a first tool half (20) with at least one mold section (21), the at least one mold section (21) having a receptacle (23) for the stationary reception of a blank ( 40), and having a second tool half (30) with at least one thrust washer (31), which can be driven in a partially deforming manner and can be pressed against the first tool half (20), the at least one mold section (21) being arranged eccentrically. Device according to Claim 6 wherein the first tool half (20) has several eccentrically arranged mold sections (21), the mold sections (21) being distributed concentrically, linearly, cross-shaped or star-shaped on the first tool half (20). Device according to Claim 6 or 7th wherein the second tool half (30) has a pressure disk (31) which is set up to reshape a plurality of blanks (40, 41) inserted in receptacles (23) of a plurality of mold sections (21). Device according to one of the Claims 6 until 8th , wherein the second tool half has at least one annular and concentrically arranged pressure disk, which is set up to reshape a plurality of blanks inserted in receptacles of a plurality of mold sections. Device according to one of the Claims 6 until 9 wherein the first tool half (20) is designed to be rotatable, the rotatable first tool half (20) being rotatable synchronously with a direction of rotation (R) of the second tool half (30).

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