Cooling block with integral heat pipe

Abstract

A cooling block includes a metallic body that defines therein a plurality of cooling channels. Each of the cooling channels includes a wicking structure for moving a working fluid through the channels. Each of the cooling channels opens into a common manifold.

Description

COOLING BLOCK WITH INTEGRAL HEAT PIPEBACKGROUND

[0001] In injection molding, process cycle time and part quality depend to a large degree on the ability to control mold tooling temperature. In particular, cooling the molded part prior to ejection from the tooling can affect severity of heat sink marks, differential shrinkage, residual stress, and other characteristics. Water is often circulated through channels in the tooling in order to provide temperature control. The water, however, can carry particles that cause clogging of the channels, which requires tooling downtime for maintenance.SUMMARY

[0002] A cooling block according to an example of the present disclosure includes a metallic body that defines therein a plurality of cooling channels. Each of the cooling channels includes a wicking structure for moving a working fluid through the channels. Each of the cooling channels opens into a common manifold.

[0003] The present disclosure may include any one or more of the individual features disclosed above and / or below alone or in any combination thereof.BRIEF DESCRIPTION OF THE DRAWINGS

[0004] The various features and advantages of the present disclosure will become apparent to those skilled in the art from the following detailed description. In this disclosure, like reference numerals designate like elements where appropriate and reference numerals with the addition of one-hundred or multiples thereof designate modified elements that are understood to incorporate the same features and benefits of the corresponding elements. The drawings that accompany the detailed description can be briefly described as follows.

[0005] Figure 1 illustrates a cooling block.

[0006] Figure 2 illustrates the cooling block with transparent walls in order to observe internal cooling channels.DESCRIPTION

[0007] Figure 1 illustrates an example cooling block 20, and Figure 2 illustrates the block 20 with transparent walls so that features within the block 20 are visible. As will be appreciated, the block 20 is adapted as an insert in an injection molding tool 21, but thisdisclosure is not limited thereto and is applicable for cooling blocks in other equipment or industries where conformal cooling is beneficial.

[0008] The block 20 is formed from a metallic material, such as aluminum or aluminum alloy, steel, or other alloy that is capable of being 3D printed. The block 20 includes a body 22, which defines the geometry of the block 20. For example, the body is solid except for cooling channels 24 formed therein. As shown, there are six such cooling channels that generally run parallel to each other, though the number and orientation can be varied in order to tailor the cooling. Each channel 24 includes a wicking structure 26 for facilitating transport of a working fluid (coolant) in the channels 24, such as but not limited to water. For example, the wicking structure 26 is a porous foam that includes pores that are adapted in size to generate capillary action to move the working fluid through the channels 24. In general, such pores are approximately 25 micrometers or less in diameter, such as 10 micrometers, 1 micrometer, or 10 nanometers.

[0009] The block 20, including the channels 24 and wicking structure 26, is formed using a 3D printing process. In that regard, the body 22 and wicking structure 26 form a single, monolithic component, i.e., without any mechanical joints or seams. Moreover, as 3D printing permits building of very thin walled structures, the channels 24 can extend into small geometric features and be located close to the surfaces of the block 20, thereby facilitating enhanced cooling.

[0010] In general, each of the channels 24 includes one end that is closed and another end that opens to a manifold 28. The channels 24 thus intersect the manifold 28 but are non-intersecting with each other. The manifold 28 is a common passage into which each of the channels 24 opens and is generally larger in cross-sectional area than each of the channels 24. The manifold 28 serves for flow of the working fluid to and from the channels 24, to carry heat out of the block 20 to a heat sink 30. For example, the working fluid is initially inserted into the channels 24 and the channels 24 are then evacuated to a low pressure. The working fluid evaporates to absorb heat in the block 20 and the vapor carries the heat out of the block 20 by convection. The vapor then condenses to reject the heat to the heat sink 30 and the condensed water then flows back into the channels for another cycle. Thus, the cooling cycle is closed loop and the same water is continuously used, as opposed to an open loop cooling in which new water is constantly provided / circulated. The wicking structure 26 allows a closed loop, highly efficient two phase cooling process to be used in industrial processes such as injection molding.

[0011] Prior known conformal cooling strategies utilize separate water lines on the molds or inserts. This often results in complex shapes that easily clog and are difficult to maintain. In the disclosed closed loop system, however, maintenance is easy, as it is limited to external components of water hoses and manifold systems.

[0012] Although a combination of features is shown in the illustrated examples, not all of them need to be combined to realize the benefits of various embodiments of this disclosure. In other words, a system designed according to an embodiment of this disclosure will not necessarily include all of the features shown in any one of the Figures or all of the portions schematically shown in the Figures. Moreover, selected features of one example embodiment may be combined with selected features of other example embodiments.

[0013] The preceding description is exemplary rather than limiting in nature. Variations and modifications to the disclosed examples may become apparent to those skilled in the art that do not necessarily depart from this disclosure. The scope of legal protection given to this disclosure can only be determined by studying the following claims.

Claims

CLAIMSWhat is claimed is:

1. A cooling block comprising: a metallic body defining therein a plurality of cooling channels, each of the cooling channels including a wicking structure for moving a working fluid through the channels; and a common manifold into which each of the cooling channels opens.

2. The cooling block as recited in claim 1, wherein the body and the wicking structure are monolithic.

3. The cooling block as recited in claim 2, wherein the wicking structure is a porous foam.

4. The cooling block as recited in claim 1, wherein the common manifold is external of the metallic body.

5. An injection mold tool comprising: a cooling block having a metallic body defining therein a plurality of cooling channels, each of the cooling channels including a wicking structure for moving a working fluid through the channels; and a common manifold into which each of the cooling channels opens.

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