EP4086560A1 - Cooling body for producing a ring cooler - Google Patents

Abstract

The invention relates to a heat sink for producing a ring cooler, formed from a tubular base body (1) on whose outer peripheral surface (U1) a large number of outwardly tapering cooling projections (2, 2a, 2b) are formed.

Description

The invention relates to a heat sink for producing a cooler and a method for producing such a heat sink.

According to the prior art, heat sinks for producing a ring cooler are generally known. Such heat sinks have a tubular base body, on the outer peripheral surface of which are formed cooling projections in the form of axially running ribs. According to the prior art, such heat sinks are usually produced by means of extrusion.

In particular, in order to achieve a high cooling capacity, it is necessary in the case of the known annular heat sinks to design the cooling ribs to have a relatively large area. As a result, annular heat sinks with a high cooling capacity are bulky and heavy or complex to manufacture.

The object of the invention is to eliminate the disadvantages of the prior art. In particular, a compact heat sink for producing a ring cooler is to be specified, which has a high cooling capacity. According to a further aim of the invention, a method for producing a heat sink that can be carried out as simply and inexpensively as possible is to be specified.

This object is solved by the features of patent claims 1 and 17. Expedient refinements of the invention result from the features of the dependent patent claims.

According to the invention, a cooling body for the production of a ring cooler is proposed, formed from a tubular base body, on the outer peripheral surface of which a multiplicity of outwardly tapering cooling projections are formed.

The configuration of the cooling projections proposed according to the invention enables the cooling body to be manufactured by means of forging, in particular hollow forging. It In particular, machining can be reduced. The proposed heat sink can be manufactured easily and inexpensively.

In the context of the present invention, the term “cooling projections” should be understood in general terms. These can be lamellae which run in the axial direction, in the circumferential direction or at an angle thereto. The slats can be formed in sections, i. H. in particular, also be spaced apart from one another in the axial direction. Cooling projections can be pyramidal, tapering to a point, conical, truncated, spherical, peg-like or hemispherical. A large number of adjacent cooling projections are expediently provided, between which cooling fluid can flow.

In the context of the present invention, the term “tubular base body” should also be understood in general terms. The tubular base body can have an essentially round or oval cross section. It is also conceivable that the tubular body has a polygonal, i. H. angular cross-section. The tubular base body does not necessarily have to be closed. It may be that the tubular base body has at least one axial and/or radial slot and/or at least one opening.

According to an advantageous embodiment, the tubular body is cylindrical. In this case, the tubular base body has an essentially annular cross-sectional area.

According to a further embodiment, the outer circumferential surface has at least three segments with cooling projections in the circumferential direction, each of which is delimited by two surfaces. The two surfaces may be axial planes intersecting along the cylinder axis. The two axial planes can form a first angle α of at most 120°. An axial center plane runs through an angle bisector of the two axial planes. The proposed segment-like design of the peripheral surface allows the production of the heat sink with a hollow forging tool which z. B. is formed of three segments.

According to a further embodiment, all of the cooling projections of each segment extend in a single direction of extent from the outer peripheral surface. i.e. the cooling protrusions of each segment can be located both in radial direction as well as in a direction oblique to the radial direction. Surprisingly, it has been shown that an excellent cooling performance can be achieved with cooling projections designed in this way.

The direction of extent expediently runs parallel to a radius lying in the axial center plane. The direction of extent essentially corresponds to a radial-linear direction of movement of a tool segment of the hollow forging tool.

According to a further embodiment, a section of a lateral surface of each cooling projection forms a second angle β of more than 0°, preferably more than 0.3°, with the direction of extension. The proposed design of the cooling projections enables trouble-free demoulding. The second angle β has a positive sign if the point of intersection between the direction of extension and the section of the lateral surface is outside the outer circumference.

According to a particularly advantageous embodiment, the first cooling projections are rotationally symmetrical in the area of the bisecting lines and the second cooling projections are non-rotationally symmetrical in the vicinity of the axial planes. The cooling projections can form rows extending in the axial direction. The cooling projections in one row are expediently designed to be identical. It has proven to be particularly advantageous if the cooling projections of rows that follow one another in the circumferential direction are offset from one another in at least one of the segments. This results in a particularly high cooling capacity.

According to a further embodiment, the outer peripheral surface has two pairs of segments which are mirror-symmetrical with respect to a plane of symmetry running through the cylinder axis or are rotationally symmetrical with respect to the cylinder axis. The proposed pairs of segments correspond to a hollow forging tool, which is formed in a corresponding manner from two pairs of tool segments. When the tool is closed, the tool segments complement each other to form a ring, the inside of which forms a matrix for producing the cooling projections in particular. A semi-finished product to be formed, for example a pipe section, is arranged in the ring. A forming force is introduced axially by means of an active part which can be moved into the ring and which can be conical at least in sections.

At least one web extending in the axial direction can be integrally formed on the outer peripheral surface of the heat sink. Furthermore, it is possible for lamellar projections to be formed on an inner peripheral surface opposite the outer peripheral surface. The lamellar projections can extend in the axial direction or be designed in the manner of a helix.

According to a further measure of the invention, a method is proposed for the production of the heat sink according to the invention, in which a base body is formed by means of hollow forging. For this purpose, the base body or a semi-finished product is introduced into a mold space. The mold space is formed by segments of a hollow forging tool. To shape the semi-finished product, an active part is moved into the mold space so that the material of the semi-finished product is pressed into a die formed by the tool segments.

Fig. 1

eine perspektivische Ansicht eines Kühlkörpers,

Fig. 2

eine schematische Schnittansicht durch einen weiteren Kühlkörper,

Fig. 3

eine vergrößerte Teilansicht gemäß Fig. 2,

Fig. 4

eine erste perspektivische Teilansicht gemäß Fig. 2,

Fig. 5

eine zweite perspektivische Teilansicht gemäß Fig. 2, und

Fig. 6

eine Schnittansicht durch Werkzeugsegmente eines Hohlschmiedewerkzeugs.

An exemplary embodiment of the invention is explained in more detail below with reference to the drawings. Show it:

1

a perspective view of a heat sink,

2

a schematic sectional view through another heat sink,

3

an enlarged partial view according to FIG 2 ,

4

a first partial perspective view according to FIG 2 ,

figure 5

a second partial perspective view according to FIG 2 , and

6

a sectional view through tool segments of a hollow forging tool.

At the in 1 1, a plurality of cooling projections 2 extend from an outer peripheral surface U1 of a tubular base body 1. The cooling projections 2 are formed in the manner of columns or pegs. Furthermore, a web 3 extending in the axial direction is integrally formed on the outer peripheral surface U1. In the area of one end face (not visible here), a circumferential flange 4 extends from the outer circumferential surface (U1), which can be provided with a circumferential groove 5 on its further circumferential surface.

The base body 1 is essentially cylindrical here. The heat sink is made from at least one metal, for example aluminum, copper, brass or another metal that can be shaped, in particular, by means of hollow forging. It is considered advantageous to use at least one metal which is characterized by high thermal conductivity.

At the in 2 The further heat sink shown makes it clear that the outer peripheral surface U1 provided with the cooling projections 2 is divided into several segments. The outer peripheral surface U1 provided with the cooling projections 2 is divided here into four segments S1, S2, S3, S4. Each of the segments S1, S2, S3 and S4 is delimited by two axial planes A1, A2, A3 and A4 which intersect along a cylinder axis Z at a first angle α of 90° here. The additional heat sink is mirror-symmetrical with respect to a plane of symmetry corresponding to the axial planes A1 and A3. The reference symbols W1, W2, W3 and W4 designate axial center planes which also intersect in the cylinder axis Z. The axial center planes W1, W2, W3 and W4 form an angle bisector with respect to the first angle α.

The cooling projections 2 of each segment S1, S2, S3 and S4 each extend in a single extension direction E1, E2, E3 and E4 from the outer peripheral surface U1. The extension directions E1, E2, E3 and E4 each run parallel to a radius lying in the corresponding axial center plane W1, W2, W3 and W4.

Each of the cooling projections 2 is encased by a lateral surface 6 . A top surface, which delimits the lateral surface 6, is denoted by the reference symbol 7. The top surface 7 runs z. B. in an angular range of 90 ° to 45 ° relative to the respective direction of extent E1, E2, E3 or E4.

How out 3 As can be seen, the lateral surface 6 is delimited by two lines L1 and L2 in an axial section perpendicularly intersecting the cylinder axis Z. A first line L1 faces an adjacent axial plane A1, A2, A3 or A4. The second line L2 faces away from the adjacent axial plane A1, A2, A3 or A4.

Each first line L1 of a cooling projection 2 forms a second angle β with the respective extension direction E1, E2, E3 or E4. The second angle β is more than 0°, in particular more than 0.3°. The second line L2 intersects viewed outwards from the outer peripheral surface U1 with the respective extension direction E1, E2, E3 or E4.

How out 3 As can also be seen, the cooling projections 2 have a different geometry with regard to the design of their lateral surface 6: cooling projections 2, which are located adjacent to the respective axial planes A1, A2, are designed asymmetrically, whereas cooling projections 2, which are located in the area of the axial center plane W1 located are substantially symmetrical or uniform in shape.

4 shows an example of a first perspective view of cooling projections 2 in the area of the axial center plane W1, figure 5 FIG. 12 shows, by way of example, in a second perspective view, cooling projections 2 in the vicinity of the axial plane A1.

How out 4 As can be seen, in the exemplary embodiment shown here, first cooling projections 2a are formed in the region of the axial center plane W1 shown here, essentially with respect to the direction of extension E1 (not shown here).

figure 5 shows the configuration of second cooling projections 2b in the vicinity of the axial plane A1 shown here. The second cooling projections 2b are non-rotationally symmetrical with respect to the extension direction (not shown here).

The cooling projections 2, 2a, 2b may form first rows R1 and second rows R2 extending in the axial direction. The cooling projections 2, 2a, 2b of a row R1, R2 are expediently designed identically. First R1 and second rows R2 immediately following one another in the circumferential direction can be offset from one another in at least one of the segments S1, S2, S3 or S4.

Although not shown in the figures, the cooling projections 2, 2a, 2b can also be configured differently. In particular, they can be configured in a prismatic, pyramidal, hemispherical, convex, lamellar, etc. manner. Furthermore, it is also possible that on an inner peripheral surface U2 of the base body 1 opposite the outer peripheral surface U1 there are provided further radially inwardly projecting lamellar cooling projections, which extend axially or are designed in the manner of a helix (not shown here).

The heat sink according to the invention can be produced easily and inexpensively from one piece, in particular by means of hollow forging.

6 shows a schematic sectional view through tool segments WS1, WS2, WS3, WS4 of a hollow forging tool, which form a matrix for the cooling projections 2, 2a, 2b in the closed state shown here. Each of the tool segments WS1, WS2, WS3 and WS4 corresponds to one of the 2 shown segments S1, S2, S3 and S4.

To produce the heat sink according to the invention, a semi-finished product formed, for example, from a tube section is introduced into a mold space formed by the tool segments WS1, WS2, WS3 and WS4. The mold space is then closed by axially movable active parts or stamps, some of which are not shown here. One of the stamps can be conical, at least in sections. To shape the semi-finished product, such a stamp is pressed into the semi-finished product so that its material flows into the die formed by the tool segments WS1, WS2, WS3 and WS4. Lamellae can be formed on an inner peripheral surface of the base body 1 by providing slot-like recesses in the punch. The stamp can also be moved in a rotating manner with respect to the semi-finished product, as a result of which lamellar projections can be produced in the manner of a helix.

Reference List

1

body

2, 2a, 2b

cooling tab

3

web

4

flange

5

groove

6

lateral surface

7

top surface

S1, S2, S3, S4

segment

E1, E2, E3, E4

direction of extension

A1, A2, A3, A4

axial plane

W1, W2, W3, W4

axial center plane

L1

first line

L2

second line

Z

cylinder axis

a

first angle

β

second angle

WS1, WS2, WS3, WS4

tool segment

R1

first row

R2

second row

U1

outer peripheral surface

U2

inner peripheral surface

Claims (17)

Cooling body for producing a ring cooler, formed from a tubular base body (1) on whose outer peripheral surface (U1) a large number of outwardly tapering cooling projections (2, 2a, 2b) are formed. Heat sink according to claim 1,
wherein the base body (1) is cylindrical. Heat sink according to one of the preceding claims,
wherein the outer peripheral surface (U1) provided with the cooling projections (2, 2a, 2b) has at least three segments (S1, S2, S3, S4) in the peripheral direction, each of which is delimited by two surfaces. Heat sink according to claim 3,
the two surfaces being two axial planes (A1, A2, A3, A4) intersecting along the cylinder axis (Z). Heat sink according to one of the preceding claims,
whereby the two axial planes (A1, A2, A3, A4) form a first angle α of at most 120° and an axial center plane (W1, W2, W3, W4) through a bisector of the two axial planes (A1, A2, A3, A4). ) runs. Heat sink according to one of the preceding claims,
wherein all cooling projections (2) of each segment (S1, S2, S3, S4) extend in a single extension direction (E1, E2, E3, E4) from the outer peripheral surface (U1). Heat sink according to one of the preceding claims,
wherein the extension direction (E1, E2, E3, E4) is parallel to a radius lying in the axial center plane (W1, W2, W3, W4). Heat sink according to one of the preceding claims,
wherein a section of a lateral surface (6) of each cooling projection (2) forms a second angle β of more than 0°, preferably more than 0.3°, with the extension direction (E1, E2, E3, E4). Heat sink according to one of the preceding claims,
wherein first cooling projections (2a) are rotationally symmetrical in the area of the bisecting lines and second cooling projections (2b) are non-rotationally symmetrical in the vicinity of the axial planes (A1, A2, A3, A4). Heat sink according to one of the preceding claims,
the cooling projections (2, 2a, 2b) forming rows (R1, R2) extending in the axial direction. Heat sink according to one of the preceding claims,
wherein the cooling projections (2, 2a, 2b) of a row (R1, R2) are designed identically. Heat sink according to one of the preceding claims,
wherein the cooling projections (2, 2a, 2b) of rows (R1, R2) following one another in the circumferential direction are offset in relation to one another in at least one of the segments (S1, S2, S3, S4). Heat sink according to one of the preceding claims,
wherein the outer peripheral surface (U1) has two pairs of segments which are mirror-symmetrical with respect to a plane of symmetry running through the cylinder axis (Z) or are rotationally symmetrical with respect to the cylinder axis (Z). Heat sink according to one of the preceding claims,
at least one web (3) extending in the axial direction being integrally formed on the outer peripheral surface (U1). Heat sink according to one of the preceding claims,
lamellar projections being formed on one of the inner peripheral surfaces (U2) opposite the outer peripheral surface. Heat sink according to one of the preceding claims,
wherein the lamellar projections extend in the axial direction or are designed in the manner of a helix. Method for producing a heat sink according to one of the preceding claims by forming a base body (1) by means of hollow forging.

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