CN211424336U - LED lamp heat radiation structure - Google Patents

Abstract

The utility model discloses a LED lamp heat radiation structure, which comprises a substrate, the heat pipe, the fin, end cover and imbibition core, use working medium as the heat carrier, rely on the capillary force that intraductal pressure differential and imbibition core provided as power, realize the circulation heat dissipation through the phase transition, there is a recess bottom the base plate, a LED chip array is used for placing, can decide the groove shape according to the array shape, there are acicular topping up and evacuation passageway at the end cover top, it is directly connected with the three-way pipe, a LED lamp heat radiation structure that the heat transfer effect is good.

Description

LED lamp heat radiation structure

Technical Field

The utility model relates to a LED equipment specifically is a LED lamp heat radiation structure.

Background

The popularization and application of the LED light source are a new revolution in the field of illumination, the luminous efficiency of the LED light source breaks through 100lm/W, and the LED light source is expected to take a leading position in the field of illumination. Compared with the traditional lighting source, the LED lamp has the advantages of long service life, low energy consumption, high controllability and the like. With the increasing demand of human beings on illumination, the LED light source develops towards high power and high integration, the heat dissipation problem becomes a core problem restricting the development of the LED light source, and the non-ideal heat dissipation will cause a series of problems such as light attenuation, reduced service life and reduced reliability.

The heat exchange enhancement can be realized by three methods of increasing the temperature difference in the heat transfer direction, increasing the surface convection heat transfer coefficient and increasing the heat exchange area. The principle of fin heat dissipation is to enhance the heat exchange effect with the ambient air by increasing the heat dissipation area, thereby obtaining a certain heat dissipation performance. The fins are sheet structures formed by expanding the original surface, and are the most common traditional heat dissipation means. The heat dissipation performance of the fin depends on the types of the fins, the materials of the fins, the efficiency of the fins, structural parameters and other factors.

SUMMERY OF THE UTILITY MODEL

Because of this, the utility model aims to provide a LED lamp heat radiation structure can effectively strengthen the heat dissipation through the fin to reach the radiating purpose of reinforcing LED lamp.

In order to achieve the above object, the utility model provides a following technical scheme: the utility model provides a LED lamp heat radiation structure, is including base plate, heat pipe, fin, end cover and imbibition core, heat pipe one end is connected perpendicularly base plate upper surface central authorities, the outer wall periphery of heat pipe is equipped with the fin, the fin sets up perpendicularly the base plate upper surface, the end cover lid is established the heat pipe upper end, end cover central authorities trompil make the outside air with the inner chamber of heat pipe communicates with each other, the base plate lower extreme has set up the recess of placing LED illuminating light source.

Furthermore, sealing materials are arranged at the joint of the heat pipe and the end cover.

Further, the fins and the base plate are connected through bolts.

Furthermore, a liquid-filled vacuum hole is formed in the substrate.

Furthermore, the substrate is provided with a micro-groove group.

Furthermore, a liquid storage cavity is laid on the micro-groove group.

Furthermore, the material of the heat dissipation structure of the LED lamp is aluminum.

Furthermore, the number of the heat pipes is at least 4 and the heat pipes are arranged in an array mode.

Further, the working medium for the heat pipe is water and/or methanol.

Further, the periphery of the substrate is filled with a sealing gasket, and the inner periphery is provided with a bottom plate support.

The technical effects of the utility model: the utility model discloses use working medium as heat carrier, rely on the capillary force that intraductal pressure differential and imbibition core provided as power, realize the circulation heat dissipation through the phase transition, have a recess bottom the base plate for place LED chip array, can decide the recess shape according to the array shape, there are acicular topping up and the evacuation passageway at the end cover top, directly are connected with the three-way pipe.

The utility model discloses the radiator thermal characteristic when still having optimized heat pipe diameter, heat pipe height, fin quantity simultaneously can be guaranteeing that the chip guarantees that the junction temperature is less than under the condition of 75 ℃, obtains the minimum LED lamp heat radiation structure of volume. A corresponding liquid filling and vacuum pumping structure and a specific method are provided, aluminum is selected as a tube shell, and water, methanol, ethanol or a mixed liquid of the three is selected as a working medium; the wire mesh liquid absorption core structure manufactured by bending and rolling the copper wire mesh is designed, has small thermal resistance and simple manufacture, and can prevent the wire mesh liquid absorption core structure from being displaced and separated from the inner wall of the heat pipe.

Drawings

FIG. 1 is a perspective view of a first heat dissipation structure of an LED lamp;

FIG. 2 is a cross-sectional view of a first heat dissipation structure of an LED lamp;

FIG. 3 is a schematic view of the liquid-filling and vacuum-pumping device of the present invention;

FIG. 4 is a perspective view of a second heat dissipation structure of an LED lamp;

FIG. 5 is a cross-sectional view of a second heat dissipation structure of an LED lamp;

FIG. 6 is a bottom view of a second heat dissipation structure of an LED lamp;

FIG. 7 is a view showing a connection structure of a first heat pipe and a fin;

FIG. 8 is a diagram of a second heat pipe and fins connection structure.

The liquid storage device comprises a base plate 1, a heat pipe 2, a rib 3, an end cover 4, a liquid absorption core 5, a sealing material 6, a groove 7, a bolt 8, a liquid filling vacuum hole 9, a micro-groove group 10, a working medium 11, a sealing gasket 12, a liquid storage cavity 13 and a bottom plate support 14.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

Fig. 1 is a schematic diagram of the structural design and the working principle of a heat dissipation structure of an LED lamp, and the main functional components include a substrate 1, a heat pipe 2, fins 3, an end cap 4, and a wick 5, and structurally, the whole body is composed of only two parts, that is, the substrate 1, the heat pipe 2, the integrated structural members of the fins 3, and the end cap 4. The working principle is the same as that of a traditional heat pipe, a working medium 11 is used as a heat carrier, the capillary force provided by the pressure difference in the pipe and the liquid absorption core 5 is used as power, the circulating heat dissipation is realized through phase change, a groove 7 is formed in the bottom of the substrate 1 and used for placing an LED chip array, and the shape of the groove 7 can be determined according to the shape of the array.

Fig. 2 is a schematic diagram of a liquid filling and vacuum pumping method of the heat dissipation structure of the LED lamp, wherein an end cover 4 is connected with a heat pipe 2 through threads, the heat pipe 2 is sealed by a sealing material 6, and a needle-shaped liquid filling and vacuum pumping channel is arranged at the top of the end cover 4 and is directly connected with a three-way pipe. When vacuum pumping is carried out, the channel 2 is closed, and the vacuum pump pumps air in the heat pipe 2 to a pre-designed vacuum degree through the channel 1; during liquid filling, the channel 1 is closed, the channel 2 is opened, and the working medium 11 with the preset volume is sucked by utilizing the pressure difference between the air in the heat pipe 2 and the atmospheric pressure; when sealing, the channel 1 and the channel 2 are closed, and the needle-shaped channel is squeezed and pinched off by the high-temperature pressure clamp to realize sealing, so that the sealing process is mature and is applied to the actual production of the copper heat pipe 2.

According to the designed LED lamp heat dissipation structure, the concept of the flat heat pipe 2 is combined for improvement, the uniform temperature type LED lamp heat dissipation structure is designed, the gravity heat pipe 2 does not contain a wick 5 structure, the working principle is consistent with that of the LED lamp heat dissipation structure, and the structure is shown in figures 4-5. The LED lamp mainly comprises an integrated structure of fins 3 and a heat pipe 2 and a base plate, wherein the fins 3 and the heat pipe 2 are connected through a bolt 8 in a threaded mode, the base plate is sealed through a circle of sealing gasket 12, liquid filling and vacuum pumping are carried out through liquid filling/vacuum holes, and the specific method is consistent with that of an LED lamp heat dissipation structure and is shown in figure 3.

Fig. 6 shows a bottom plate structure, which is a main improvement, the micro-groove group 10 is arranged on the bottom plate to form a simple flat heat pipe 2, and the bottom plate support 14 can prevent the micro-groove group 10 from directly contacting with other structures, thereby protecting the micro-groove group from deformation. On the basis of the LED lamp heat dissipation structure, the flat heat pipe 2 structure is additionally arranged at the bottom, so that the temperature equalization performance of the heat radiator can be greatly improved, according to the heat exchange theory, when the input heat flux density is higher, the temperature equalization performance of the temperature equalization plate is much stronger than that of the material per se, the hot spot phenomenon can be effectively prevented, the thermal stress of the bottom plate is reduced, and the service life of an LED element is prolonged. The disadvantage of this structure is that the processing is complicated, which is not favorable for reducing the cost.

For higher input heat flux density, a method of increasing the number of the internal heat pipes 2 may be selected to improve the heat dissipation performance, and a specific scheme is shown in fig. 7-8, a heat pipe bundle formed by a plurality of heat pipes 2 may be arranged according to actual conditions, so that the heat conduction capability in the heat transfer direction may be greatly improved, and further the heat dissipation performance is improved, but adverse consequences of increasing the cost and the processing difficulty may also be brought at the same time.

Matching the working temperature of the heat pipe 2 for LED heat dissipation, acetone (CH3OHCH3), ethanol (CH3CH2OH), methanol (CH3OH) and water (H2O) can be selected as the working medium 11, if the LED chip junction temperature is controlled within 70 ℃, the working medium 11 in the pipe can enter a high-efficiency phase-change heat transfer state only when reaching a boiling point below 70 ℃, the normal boiling point of acetone is 56.25 ℃, the normal boiling point of methanol is 64.7 ℃, the normal boiling point of ethanol is 78.3 ℃, the normal boiling point of water is 100 ℃, and for the working medium 11 with the boiling point exceeding the working temperature, the boiling point can be reduced by vacuumizing the pipe, the boiling point of water can be reduced to 60 ℃ by vacuumizing the pipe to 0.2 atmospheric pressure, and the boiling point of ethanol can be reduced to 60 ℃ by vacuumizing to 0.47 atmospheric pressure. Because acetone has certain toxicity and corrosivity, generally used for experiments, methanol, ethanol, water or a mixed liquid of the three is mostly used as the working medium 11 in engineering application, and besides the working temperature and the characteristics of the medium, the compatibility of the working medium 11 and the tube shell material should be considered.

Common types of wicks 5 are micro-grooves, wire mesh cores, sintered metal felts, and the like. The sintered metal felt is the most common type of the liquid absorption core 5 at present, firstly, a shaping rod and a copper pipe are nested together, a certain gap is reserved between the shaping rod and the copper pipe, then copper powder is filled in the gap, the copper powder is placed in a sintering furnace for sintering, the copper powder is sintered on the inner wall of the copper pipe, finally, the shaping rod is pulled out, the sintered copper pipe can be bent or flattened according to the actual use condition, the sintering process is quite mature, and the liquid absorption core 5 is basically manufactured by the method for the copper heat pipe 2 on the market. The micro grooves are formed by manufacturing a series of grooves on the inner wall of the heat pipe 2 and are used as a channel for backflow of condensed liquid to form a liquid absorption core 5 structure, the grooves can be rectangular, triangular or circular, but the micro grooves are manufactured on the inner wall of the heat pipe 2, so that the processing difficulty is high and the processing cost is too high. The wire mesh core is formed by rolling a mesh material with fine holes into a tube shape and tightly attaching the mesh material to the inner wall of the heat pipe 2 to form a liquid absorption core 5 structure.

The whole shape of the current LED chip array is mostly circular or square, for the high-power LED chip array for daily illumination, the power is different from several watts to dozens of watts, the diameter of the LED chip array with the general power of 20W is about 50mm (or the length and the width are 50mm), for the LED chip array with the specification and the size, the allowance of 20mm is reserved, the bottom plate is designed to be a disc with the diameter of 70mm, the bottom part is provided with a circular groove 7 with the diameter of 50mm for installing the LED chip array, and the depth of the groove 7 is 4 mm. The heat dissipation overall structure of the column type heat pipe 2 is cylindrical (convenient for installation in storage and transportation), and according to the condition, it can be known that the width W of the fin 3 and the diameter d of the heat pipe 2 should satisfy the condition of 2W + d being 70mm, the height H of the fin 3 is consistent with the height of the heat pipe 2, and the thickness of the fin 3 is 2 mm. Considering the whole structure and the heat input power, the diameter d of the heat pipe 2 is designed to be 6-16 mm, the height H of the heat pipe 2 is designed to be 60-90 mm, and the number N of the fins 3 is designed to be 8-18.

The test result shows that the LED lamp heat dissipation structure with the minimum volume can be obtained under the condition that the chip ensures that the junction temperature is less than 75 ℃.

The above description is only for the preferred embodiment of the present invention, and the structure is not limited to the above-mentioned shape, and any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (10)

1. The utility model provides a LED lamp heat radiation structure, its characterized in that, including base plate, heat pipe, fin, end cover and wick, heat pipe one end is connected perpendicularly base plate upper surface central authorities, the outer wall periphery of heat pipe is equipped with the fin, the fin sets up perpendicularly the base plate upper surface, the end cover lid is established the heat pipe upper end, end cover central authorities trompil make outside air with the inner chamber of heat pipe communicates with each other, the base plate lower extreme has set up the recess of placing LED illuminating light source.

2. The heat dissipation structure of claim 1, wherein: and sealing materials are arranged at the joint of the heat pipe and the end cover.

3. The heat dissipation structure of claim 1, wherein: the fins are connected with the base plate through bolts.

4. The heat dissipation structure of claim 1, wherein: the base plate is provided with a liquid-filled vacuum hole.

5. The heat dissipation structure of claim 4, wherein: the substrate has a plurality of microgrooves.

6. The heat dissipation structure of claim 5, wherein: and a liquid storage cavity is laid on the micro-groove group.

7. The heat dissipation structure of claim 1, wherein: the LED lamp heat radiation structure is made of aluminum.

8. The heat dissipation structure of claim 1, wherein: the number of the heat pipes is at least 4 and the heat pipes are arranged in an array mode.

9. The heat dissipation structure of claim 1, wherein: the working medium for the heat pipe is water and/or methanol.

10. The heat dissipation structure of claim 1, wherein: the periphery of the substrate is filled with a sealing gasket, and the inner periphery of the substrate is provided with a bottom plate support.

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