JP2024049332A - Heat sink for UV LED curing device - Google Patents

Abstract

[Problem] To provide an air-cooled heat sink with excellent cooling efficiency, which shows a cooling effect similar to that of a water-cooled type, even though it is an air-cooled type. [Solution] The heat sink includes a heat sink 10 having UV LEDs attached to one side and arc grooves on the other side into which a number of heat pipes 20 are closely inserted, a fixing member 30 having arc grooves corresponding to the arc grooves of the heat sink to fix and connect the heat pipes to the heat sink, and a number of stacked fins 40 stacked and supported in parallel with the heat pipes. [Selected Figure] Figure 2

Description

The present invention relates to a heat sink for an air-cooled UV LED curing device, and more specifically, to a heat sink for a UV LED curing device that includes a heat sink plate to which UV LEDs are attached, a number of heat pipes, a fixing member that fixes and connects the heat pipes to the heat sink plate, and a number of stacked fins that are stacked and supported in parallel with the heat pipes.

UV (ultraviolet) hardeners are devices that harden ultraviolet-curable resins that contain photoinitiators, and are widely used in various industrial fields to carry out adhesion, coating, printing, and other processes. UV LED hardeners use LEDs as the ultraviolet light source, and have the advantage of being smaller in size and consuming less electricity than conventional UV lamps.

In UV LED curing devices, the heat generated by the LED, which is the light source, has a negative effect of reducing the lifespan and light output of the UV LED. For this reason, various UV LED curing devices equipped with a cooling device, i.e., a heat sink, that efficiently cools the heat generated by the UV LED have been proposed.

For example, Korean Patent Registration No. 10-1623299 (May 16, 2016) discloses a cooling means for a UV LED curing device for large-area coating that uses UV LEDs to cure products coated with ultraviolet-curable resin, the cooling means being composed of a heat sink on which an LED module is installed, a water-cooling jacket surrounding the heat sink, and a radiator equipped with a cooling water circulation path.

And Korean Patent Registration No. 10-1723130 (March 29, 2017) discloses a cooling module in an ultraviolet curing device used in the bonding process of display panels, which includes a metal block attached to the rear surface of a light-emitting unit having multiple LEDs, and a cooling tube that circulates a refrigerant along the metal block.

In addition, Korean Patent No. 10-2016288 (August 23, 2019) states that UV
The present invention discloses a UV ink curing device for printing using LEDs, the UV ink curing device including a first case and a second case through which a printed material passes, a UV LED board that irradiates UV light toward the printed material inside the first case, a heat sink that releases heat generated by the UV LED board, and a heat dissipation cooling fan that circulates air through the heat sink.

Finally, Korean Patent Registration No. 10-2402027 (May 20, 2022) discloses an LED UV curing device that is mounted on a normal UV printing device and can prevent deformation of printed matter and deterioration of print quality by improving the heat dissipation structure. Attached FIG. 1 shows the curing module of the LED UV curing device, which includes a first module A arranged above the printed matter and a second module B arranged below the printed matter.

The first module A irradiates the surface of the printed material with UV light and is composed of a housing A1, a light irradiation unit A2, a reflector A3, a diffusion plate A4 and a heat dissipation section A5. The heat dissipation section A5 includes a heat sink A51, a heat dissipation fan A52 and a heat pipe A53, and the heat sink A51 includes a heat dissipation plate A511 and a heat dissipation fin A512.

The heat sink according to the present invention may correspond to the heat dissipation part A5 in the LED UV curing device shown in FIG. 1. Explanations of other unexplained reference symbols in FIG. 1 will be omitted.

Korean Patent No. 10-1623299 (May 16, 2016) Korean Patent No. 10-1723130 (March 29, 2017) Korean Patent No. 10-2016288 (August 23, 2019) Korean Patent Registered No. 10-2402027 (May 20, 2022)

The heat sinks generally used in UV LED curing devices can be divided into air-cooled and water-cooled types. Air-cooled types have the advantages of simpler structure and lower manufacturing costs compared to water-cooled types, but have the disadvantage of relatively low cooling effect.

Therefore, the object of the present invention is to provide an air-cooled heat sink that is highly suitable for use in a cooling device for a UV LED curing device, and has excellent cooling efficiency, so that it exhibits a cooling effect similar to that of a water-cooled type, even though it is air-cooled.

Another object of the present invention is to provide an air-cooled heat sink that allows for easy adjustment of cooling efficiency depending on the intended use of the UV LED curing device, and thus allows for quick and easy assembly and maintenance.

The heat sink for the UV LED curing device according to the present invention is

A metal heat sink 10 on which UV LEDs 11 are attached in a row on one side and on which arc-shaped upward arc grooves 12 extending to a predetermined length L1 are arranged in a row on the other side;

A cylindrical metal tube with both ends sealed and filled with liquid, a lateral support part 21 that is tightly inserted into the upward arc groove 12 of the heat sink 10, and multiple heat pipes 20 that have vertical bent parts 22a, 22b that are bent perpendicularly to the heat sink 10 from both ends of the lateral support part 21;

A fixing member 30 that covers the lateral support portion 21 of the heat pipe 20 and fixes and connects the heat pipe 20 to the heat sink 10, and has downward arc grooves 31 aligned along the length on one side corresponding to the upward arc grooves 12;

It is characterized in that it is composed of a number of stacked fins 40; a thin metal plate that is inserted and supported by the vertical bent parts 22a, 22b on both sides of the heat pipe 20 and arranged at regular intervals on the other side of the heat sink 10, a number of pipe insertion holes 41 into which the vertical bent parts 22a, 22b are closely inserted, and a sleeve 42 protrudes around the pipe insertion holes 41 at a certain height L3.

The upward arc grooves 12 of the heat sink 10 are arranged alternately so that the ends of adjacent upward arc grooves 12 pass each other.

The heat pipe 20 and the stacked fins 40 connected to the heat sink 10 are assembled and separated into a stacked fin module M1, M2.
The heat exchanger is characterized in that it is constructed by inserting and fixing 20 to 100 stacked fins 40 into 8 to 16 heat pipes.

The heat sink for a UV LED curing device according to the present invention has a cooling effect similar to that of a water-cooled type, even though it is an air-cooled type, because the heat generated by the UV LED 11 is transferred to the stacked fins 40 through the heat sink 10 and the heat pipe 20 and then quickly diffused into the air.

The heat sink for a UV LED curing device according to the present invention can easily adjust the cooling efficiency by adjusting the number and size of the heat pipes 20 and stacked fins 40, and can also be easily assembled and disassembled, as well as maintained and repaired, using the stacked fin modules M1 and M2.

1 is a diagram illustrating the structure of a conventional LED UV curing device. FIG. 1 is a perspective view of a heat sink according to an embodiment of the present invention. FIG. 3 is a front view of FIG. 2 . FIG. 3 is a side view of FIG. 2 . FIG. 2 is a perspective view of the heat sink 10. FIG. 2 is a perspective view of the heat pipe 20. FIG. 2 is a perspective view of the fixing member 30. FIG. 2 is a plan view of the stacked fin 40. FIG. 2 is a side view of the stacked fin 40. FIG. 10 is a perspective view of a heat sink 10a according to another embodiment of the present invention. FIG. 3 is a perspective view of the stacked fin module M1 used in FIG. 2. FIG. 13 is a perspective view of a heat sink according to still another embodiment of the present invention.

The present invention will now be described in detail with reference to the attached drawings. However, the attached drawings are merely illustrative of preferred embodiments of the present invention, and the scope of the invention is not limited by these embodiments. Furthermore, detailed descriptions of configurations that are essential to the implementation of the present invention but that have been introduced in the prior art or that can be easily implemented by ordinary engineers using publicly known techniques will be omitted.

As shown in the attached Figs. 2 to 4, the heat sink for a UV LED curing device according to the present invention comprises a heat sink 10 to which the UV curing device LEDs are attached, a number of heat pipes 20, a fixing member 30 for fixing and connecting the heat pipes 20 to the heat sink 10, and a number of stacked fins 40 stacked and supported in parallel with the heat pipes 20. A conventional cooling fan (not shown) may be arranged on the side of the stacked fins 40.

First, the heat sink 10 is a rectangular plate made of metal, with UV LEDs 11 attached in a row on one side and a number of upward arc grooves 12 arranged in a row on the other side. Attached FIG. 5 shows an example of a rectangular heat sink 10 made of copper, which has excellent thermal conductivity, and has dimensions of 95 mm wide, 340 mm long, and 7 mm thick.

The UV LED 11 may be an LED that emits ultraviolet light in a wavelength range of about 315 to 400 nm with an output of about 200 W per LED. The UV LED 11 may be a COB type or a package type, and may be attached to one side of the heat sink 10 using a normal fixing screw. For this purpose, the UV LED 11 in FIG. 4 is provided with a screw hole.

The upward arc groove 12 is, for example, an arc-shaped groove with a radius of 3 mm, preferably a semicircular groove, and its length L1 is preferably about 60 to 80 mm, which is shorter than the width of the heat sink 10. The attached Figure 5 shows the heat sink 10 with 48 upward arc grooves 12 of the same length L1 arranged in a line along the length of the heat sink 10.

The heat pipe 20 is a cylindrical metal tube with both ends sealed and filled with liquid, as shown in FIG. 6, and has a structure in which the horizontal support part 21 and the vertical bent parts 22a and 22b are bent into a "U" shape. The metal tube that constitutes the heat pipe 20 is made of copper material, and is preferably filled with water.

The lateral support portion 21 is inserted closely into the upward arc groove 12 of the heat sink 10, and its radius and length L1 are the same as the radius and length L1 of the upward arc groove 12. It is preferable that about half of the circular cross section of the lateral support portion 21 is accommodated in the upward arc groove 12.

The vertical bends 22a and 22b are bent from both ends of the horizontal support 21 in a direction perpendicular to the heat sink 10, and the ends are sealed. The number of heat pipes 20 is the same as the number of upward arc grooves 12 provided on the heat sink 10.

The fixing member 30 covers the lateral support portion 21 of the heat pipe 20 and functions to fix and connect the heat pipe 20 independently to the heat sink 10. The fixing member 30 may be made of aluminum, and its length is the same as the length of the heat sink 10.

As shown in FIG. 7, downward arc grooves 31 corresponding to the upward arc grooves 12 are provided in a line along the length direction on one surface of the fixing member 30. The radius and spacing of the downward arc grooves 31 are the same as the radius and spacing of the upward arc grooves 12. Therefore, the upward arc grooves 12 and the downward arc grooves 31 are aligned to surround both the upper and lower halves of the lateral support portion 21.

The other side of the fixing member 30 is provided with a heat dissipation groove 32 along the length direction. The heat dissipation groove 32 functions to expand the surface area of the fixing member 30 and enhance the heat dissipation effect. The fixing member 30 may be attached to the heat dissipation plate 10 by welding together with the lateral support portion 21 of the heat pipe 20, or may be connected to the heat dissipation plate 10 by separate fixing screws. For this purpose, the heat dissipation plate 10 of FIG. 5 is provided with a number of screw holes at appropriate positions.

Finally, the stacked fins 40 are in the form of thin metal plates, and are arranged in multiple layers at regular intervals on the other side of the heat sink 10 while being supported by the vertical bent portions 22a and 22b. Figure 8 shows an example of a rectangular stacked fin 40 made of an aluminum thin plate with a thickness of 0.3 to 0.7 mm, and measuring 115 mm wide and 84 mm long.

The stacked fins 40 are perforated with a number of pipe insertion holes 41 into which the vertical bent portions 22a, 22b on both sides of the heat pipe 20 are closely inserted. The inner diameter of the pipe insertion holes 41 is the same as the diameter of the vertical bent portions 22a, 22b. Therefore, the stacked fins 40 are arranged in multiple layers at regular intervals while being inserted and supported by the vertical bent portions 22a, 22b.

It is preferable that the pipe insertion hole 41 of the laminated fin 40 is provided with a sleeve 42 having a predetermined height L3 as shown in FIG.
The diameter of the sleeve 42 is equal to the diameter of the longitudinal bent portions 22a and 22b. Therefore, the sleeve 42 functions to increase the supporting force of the stacked fins 40 against the longitudinal bent portions 22a and 22b, and at the same time to uniformly space the vertical intervals between the stacked fins 40. The height H of the sleeve 42 is preferably 1.5 to 3 mm.

As shown in FIG. 5, it is preferable that the upward arc grooves 12 arranged on the heat sink 10 are arranged alternately one by one so that the both side ends of adjacent upward arc grooves 12 pass each other. In this way, the vertical bent portions 22a, 22b of adjacent heat pipes 20 and the corresponding pipe insertion holes 41 of the stacked fins 40 are also arranged alternately in a zigzag pattern as shown in FIG. 6 and FIG. 8.

Therefore, sufficient space is secured between the vertical bent portions 22a and 22b, and the wind provided by the cooling fan (not shown) installed on the side of the stacked fin 40 creates a vortex phenomenon, which enhances the heat dissipation effect, and the spacing between the pipe insertion holes 41 is widened, which increases the structural strength of the stacked fin 40.

Incidentally, if the vertical bent portions 22a, 22b of the heat pipe 20 are arranged in a row, the adjacent vertical bent portions 22a, 22b will come into close contact with each other to create a wall that blocks the air flow, resulting in a relatively reduced heat dissipation effect. Also, if the pipe insertion holes 41 of the stacked fins 40 are arranged in a row, the spacing between the adjacent pipe insertion holes 41 will be too narrow, and even a slight mistake could result in the stacked fins 40 being bent or cut along the pipe insertion holes 41.

So far, we have described the use of a heat sink 10 in which the ends of the upward arc grooves 12, which have the same length L1, are alternately arranged so that they cross each other. Figure 10 shows another embodiment of the present invention, a heat sink 10a in which two types of upward arc grooves 12a, 12b, which have different lengths L1a, L1b, are alternately arranged. In the heat sink 10a, both side ends of two adjacent upward arc grooves 12a, 12b are also alternately arranged so that they cross each other. When using the heat sink 10a of Figure 10, two types of heat pipes (not shown) must be used in which the lengths of the lateral support parts 21 are different depending on the lengths L1a, L1b of the upward arc grooves 12a, 12b.

Furthermore, according to a preferred embodiment of the present invention, the heat pipes 20 and stacked fins 40 coupled to the heat sink 10 may be assembled and separated in the form of one stacked fin module M1, M2. In this case, the stacked fin modules M1, M2 may be configured by inserting and fixing 20 to 100 stacked fins 40 into 8 to 16 heat pipes 20.

Attached Figure 11 shows a stacked fin module M1 consisting of 12 heat pipes 20 and 51 stacked fins 40, and Figure 2 shows an example of a heat sink to which four such stacked fin modules M1 are combined. Attached Figure 12 shows an example of a stacked fin module M2 consisting of 12 heat pipes 20 and 73 stacked fins 40, and a heat sink to which four such stacked fin modules M2 are combined.

The specifications of the heat pipes 20 and stacked fins 40 used therein may be appropriately changed depending on the application of the stacked fin modules M1 and M2, and the number of stacked fin modules M1 and M2 to be combined with the heat sink 10 may be determined depending on the application of the heat sink. By using such stacked fin modules M1 and M2, the heat sink according to the present invention can be more easily assembled and disassembled, which has the effect of making it convenient to maintain and repair the heat sink.

10, 10a: heat sink 11: UV LED
12, 12a, 12b: Upward arc groove 20: Heat pipe
21: Lateral support portion 22a, 22b: Vertical bending portion 30: Fixing member 31: Downward arc groove 32: Heat dissipation groove 40: Stack fin
41: Pipe insertion hole 42: Sleeve
L1: Length of the upward arc groove 12 L2: Length of the vertical bent portions 22a, 22b L3: Height of the sleeve 42 M1, M2: Stacked fin module

Claims (2)

a rectangular metal heat sink (10) having UV LEDs (11) attached in a row on one side and arc-shaped upward arc grooves (12) extended to a predetermined length (L1) arranged in a row on the other side;
a plurality of heat pipes (20) each having a lateral support part (21) which is tightly inserted into the upward arc groove (12) of the heat sink (10) and a vertical bent part (22a, 22b) which is bent from each of the lateral support part (21) in a direction perpendicular to the heat sink (10);
a fixing member (30) for covering the lateral support portion (21) of the heat pipe (20) to fix and connect the heat pipe (20) to the heat sink (10), the fixing member (30) having a downward arc groove (31) corresponding to the upward arc groove (12) arranged in a line on one surface along the length direction;
a plurality of stacked fins (40) which are thin metal plates arranged in layers at regular intervals on the other surface of the heat sink (10) while being inserted and supported by the vertical bent portions (22a, 22b) on both sides of the heat pipe (20), and which have a plurality of pipe insertion holes (41) into which the vertical bent portions (22a, 22b) are closely inserted, and sleeves (42) protrude around the pipe insertion holes (41) at a certain height (L3);
The arc grooves (12) of the heat sink (10) are arranged alternately one by one so that both side ends of the adjacent upward arc grooves (12) pass each other, the vertical bent portions (22a, 22b) of the heat pipe (20) are arranged alternately so that both side ends of the upward arc grooves (12) correspond to each other, and the upward arc grooves (12) of the heat sink (10) and the downward arc grooves (31) of the fixing member (30) are configured to together surround the surface of the lateral support portion (21). The heat sink for a UV LED curing device according to claim 1, characterized in that the heat pipes (20) and stacked fins (40) are assembled in the form of one stacked fin module (M1, M2) on the heat sink (10), and the stacked fin module (M1, M2) is configured by inserting and fixing 20 to 100 stacked fins (40) into 8 to 16 heat pipes (20).

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