Heat removal device. RU patent 2507614.

FIELD: heating.

SUBSTANCE: heat removal device consists of a housing with a heat sink, elastic elements, which are arranged in it and installed between the heat sink and a heat-stressed electronic module, a heat-conducting structure located between the heat sink and the heat-stressed electronic module; the heat sink has finning and inclined surfaces and is installed by means of fastening assemblies in the housing wall; on outer and inner surfaces of the heat sink there are heat-conducting gaskets, and elastic elements are located between the heat sink and the housing.

EFFECT: improvement of the device.

5 cl, 6 dwg

The device heat relates to the field of electronics and is intended for removal of heat from thermal loaded elements of electronic radio equipment in pressurized and unpressurized compartments on Board the aircraft operating in harsh climatic conditions and in conditions of influence of vibration and shock loads. The device can be used in structure of modular devices, manufactured according IEEE 1101.1-1998, the IEEE Standards for Mechanical Core Specifications for Microcomputers and IEEE 1101.2-1992, IEEE Standard for Mechanical Core Specifications for Conduction-Cooled Eurocards.

It is known that the most effective way of removing heat from radioactive elements - conductive, which is determined by the quality of thermal contact made between and cavity heat-elements of the design as well as the required thermal conductivity of materials of the construction elements. Quality assurance thermal contact is in contradiction with the requirement of simplicity of installation the electronic module to the product and the possibility of dismantling. When replacing the electronic module dismantle the minimum number of operations, the maximum keeping the hull of items of electronic equipment («Design-technological designing of electronic equipment», edited by Professor V.A. , - M, Publishing house of MGTU of a name of AD Bauman, 2005, p. 114). As a rule, before the dismantling of the electronic module it is necessary to weaken fixing nodes and exclude thermal contact the electronic module to the enclosure.

Known technical decision on the application of USA №2008158828, H05K 7/20, publ. 2008.07.03, in which the heat sink heat sink installed on element attached to the Board by means of springs.

Disadvantages: restriction of the use solution on the level of vibration due to the concentration in the surface mass element in the absence of rigid fixation of the heat sink; the decision is not consistent with the known principles of modularity design due to the large dimensions and ineffective as a heat sink, transmitting heat for near elements of the device.

Known technical solution chosen as the prototype (US patent # 7277291, H05K 7/20, publ. 2007.10.02), which is the device of a telescopic type, capable to transfer heat from the electronic module to the outside of the hull. It consists of a hosted in the building of the heat sink, the elastic element, gaskets and heat conducting base with a cavity in the form of a blind hole where you are installing the heat sink, consisting of a piston and a heat-transmitting parts, having the ability to move in a cavity in the vertical direction, the side surface is the track surface. Thermal contact between the heat sink and the inner surface of the cavity provides heat transfer from electronic module into the heat sink. Inside the heatsink installed elastic element - spring, providing the pressing heat sink to the outside of the hull, heat from the base to the constant heat heat sink contact with the outer panel of the housing and base with electronic module. Limitations: the presence of one surface of thermal contact between electronic module and the basis on which establishes a heat conductive lining does not allow to use the full resource of the device. The side surface of the cavity of the base and the surface of the heat sink, goes into waterside views of the external panel and are characterized by high thermal resistance and an increase in distance between the outer panel of the housing and surface element (hereinafter - TOE) area of thermal contact between the heat sink and the base decreases, accompanied by an increase in the area of the outer surface of the device, the increase in the length of the path extracting heat (from the TOE to the outside of the casing) and the increase of the heat capacity of the host. Assembly heat sink is fixed external wall of the enclosure when withdrawing which it falls out of the ground, making it difficult operation to dismantle parts of your device. Significant dimensions of the device do not allow to manufacture the product in accordance with the IEEE 1101.2-1992. The need to ensure thermal contact through the side surface telescopic systems requires a high accuracy and quality of processing the lateral surfaces of the heat sink base and the reason of occurrence of piston effect when the device. Drainage hole, made in the cavity of the Foundation, is a source of dust and all kinds of other contamination. All these components of the known solution help retain heat inside of the product casing. While the impact on the product vibration, dust, or salt fog probability of mechanical failure of the product is increased, simultaneously reduces heat removal device properties.

The technical result of the claimed invention is to provide constant quality of thermal contact between electronic module (hereinafter application - ) and the housing of the device, simplifying installation and dismantling the electronic module. Additional technical result - providing design modularity electronic module and compatibility with known standards on the hull.

To achieve the specified result in the device heat, consisting of housing hosting the a heatsink elastic elements mounted between heat sink and an electronic module, heat-conducting structure, located between the heat sink and an electronic module, heat sink is made with fins and sloped surfaces and installed using nodes of fixation in the housing wall without a thermal contact with an electronic module, the external and internal surfaces of the heat sink are thermally conductive seals, and elastic elements are located between the heat sink and chassis. With elastic elements represent rubber dampers or metal springs. Moreover, the mentioned fin performed along the direction of the rising heat flux and is located in the wall of the casing. Moreover, the mentioned sloping surfaces are made in the locations of nodes fixation. Moreover node commit consists of a shaft with threaded surface and installed with the possibility of reciprocating motion along its axis, at least, two waypoints prismatic form with sloping surfaces, matched with sloping surfaces of the heat sink.

The proposed device for heat dissipation is illustrated with drawings presented in figures 1-6.

Fig.1 - a view of the outer wall of the chassis.

Figure 2 - view of the heat sink with groups of elastic elements in axonometric projection.

Figure 3 - the view of the heat sink with nodes fixation of axonometric projection.

Figure 4 - fixed (operating position) heat sink.

Figure 5 - view on the heat sink with elastic elements from finning in axonometric projection.

6 - the view of the heat sink with elastic elements from the side.

The drawings are shown:

1 - body;

2 - heat;

3 - heat-conductive strip;

4 - heat conductive structure;

5 - elastic elements;

6. - lamellas;

7 - inclined surface;

8 - elastic strip;

9 - tabs;

10 - bushing;

11 - shaft with threaded surface;

12 - ;

13 - groove.

The device contains a body heat 1 (1-6) mantle heat sink 2 (1, 4), which is set in the window (Fig. not shown) housing wall 1 (1-6) from the inside. On the inner surface of the heat sink 2 (1, 4)are located elastic strip 3 (figure 2, 4, 6), heat-conductive structure 4 made, for example, from the paste KPT-8 or it can be a plate F. Berquist, and elastic elements 5, for example, rubber shock-absorbers or screw or flat metal springs. The outer surface of the heat sink 2 (1, 4), performed with finning 6 (3, 5) and sloping flat surfaces 7 (figure 3, 4, 5). By finning 6 (3, 5) heat sink 2 (1, 4), installed heat-conductive strip 8 (figure 2, 4, 5, 6)with a thickness of size larger than the thickness of thermal conductivity of gaskets 3 (figure 2, 4, 6). Ribs in 6 (3, 5) located along the direction of the rising heat flow devices. Sloping surfaces 7 (figure 3, 4, 5) performed in the locations of nodes fixation (not shown) type «wedge-shaped clamp». Each node includes a shaft fixation with threaded surface and, for example, two release 9 (figure 2, 3, 4), prismatic forms with inclined surface, the mating with an inclined surface of the heat sink 2 (1, 4). Claws 9 (figure 2, 3, 4), installed in the hole (not shown) housing wall 1 (1-6) and attached to it with the sleeves 10 (figures 2, 3, 4)have the opportunity to reciprocating motion along the axis of the shaft 11 (figure 2, 3, 4) with threaded surface, record heat sink 2 (1, 4) in the wall of the body 1 (1-6). Heat conductive structure 4 2, 4, 6) using clamps 9 (figure 2, 3, 4) tightly pressed against the surface 12 (figure 4), which is placed in a metal housing PCB installed on its surfaces, (not shown). In 6 (3, 5) it is executed a groove 13, for example, the cylindrical form, to capture the heat sink 2 (1, 4), for example, instrument or fingers on its external side.

The device heat works as follows.

In the initial position the heat sink 2 is elastic - state, as one side is influenced by the elastic force thermally conductive strips 8, and on the other hand - elastic force elements 5. Overcoming the force of gaskets 8, elastic elements 5 press the movable heat sink 2 to a wall of the case 1. When tightening the shaft 11 with threaded surface claws 9 are driven and through the inclined surface of 7 to transmit power on the heat sink 2, shifting it to 12.

Allocated heat, perceived housing 12 and then through structure 4 is put on the heat sink 2, falling to its entire volume. The abstraction of heat into the surrounding space in two directions: one part of the heat is dissipated through the fins 6 with the location along the edges of the rising heat flow formed the outer surface of the housing wall 1, and the other part of the heat flow - through elastic linings 3 and elastic strip 8 is transmitted to the wall of the housing 1, then diffused in the surrounding space of the entire surface of the body 1. Thus, the abstraction of heat in two areas increases the overall efficiency of heat removal from the 12.

Tightening the shaft 11 with threaded surface through the tabs 9 creates an additional effort to force thermally conductive strips 8, which overcomes the effect of elastic elements 5, that leads to displacement of heat sink 2 to 12. Sloping surfaces 7 form a wedge-shaped clamp than you fix a heat sink 2. When shifting the heat sink 2 to 12 loss occurs thermal contact with the wall of the housing 1, because the thickness of the heat conductive strip 8 performed in size than the thickness of the heat conductive strip 3.

When removing the shaft torque with threaded surface heat sink 2 returns to the position at which the heat-conductive structure 4 is not touching the 12, which provides a simple removing and installing the heat sink 2.

With the dismantling of the device in case of emergency modes of operation, for example, if imperfectly expanded operating temperatures, refusal etc. to capture heat sink 2 is used groove 13.

Studies have shown that the most effective material for heat sink 2, building 1 and retainers 9 is aluminum alloy type of 6. For thermally conductive strips 3, thermally conductive strips 8, heat-conducting structure 4 can be selected thermal interface material companies Bergquist, and for the elastic element 5 - rubber type IRP or BUT. Sleeve 10 are made of metal, for example, of aluminium alloy D16, 18 or stainless steel 12X18H10T etc. and shaft with threaded surface of steel, A12.

The device works effectively in modular designs using that correspond to the standard «Euromechanics» formats 3U etc.

Unlike the original, where thermal contact is provided by a spring, that in the conditions of vibration is not enough to ensure the permanent quality of thermal contact between and body of the device, in the proposed technical solution, the consistency and quality of thermal contact area is ensured by the use host fixation type «wedge-shaped clamp». The abstraction of heat in the nearest analogue is only in one direction in the same proposed technical solution heat dissipation in two directions increases efficiency (quality) heat sink. Replace item in the prototype is done only when the complete dismantling of the device, the proposed invention sufficiently to loosen the tabs that accompanied -conducting structure from and provides easy retrieval and replaced without dismantling the walls of the enclosure. With the full extraction of fasteners is not happening drop rolling of product design, which is a significant advantage in the product. The proposed invention is fully compatible with the operating standards for the design of electronic modules of type «Euromechanics».

Thus, due to the presence of the distinctive features in the device heat removal is achieved-the claimed technical result - to ensure the permanent quality of thermal contact between and mounting, simplifying installation and dismantling of the electronic module and software modularity of the design of the electronic module and compatibility with known standards on the hull.

Tests showed the workability of the proposed device. It can be realised on any instrument-making enterprise.

1. Device dissipation of heat, consisting of housing hosting the heat sink, elastic elements mounted between heat sink and an electronic module, heat-conducting structure located between the heat sink and an electronic module, wherein the heat sink is made with fins and sloped surfaces and installed using nodes of fixation in the housing wall without a thermal contact with an electronic module, the external and internal surfaces of the heat sink there are thermally conductive seals, and elastic elements are located between the heat sink and chassis.

2. The device according to claim 1, wherein the elastic elements represent rubber dampers or metal springs.

3. The device according to claim 1, characterized in that said fin performed along the direction of the rising heat flux and is located in the wall of the casing.

4. The device according to claim 1, characterized in that the said sloping surfaces are made in the locations of nodes fixation.