JP2010251114A - Water-cooled led lighting system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a water-cooled LED lighting system for achieving higher output by using cooling water for forcibly cooling a light source unit and a control circuit unit. <P>SOLUTION: The water-cooled LED lighting system 1 includes a housing 2, the light source unit 3 using an LED as a light source, a water cooling unit 5 having a water cooling jacket 20, a radiator 21, a circulation pump 23 and a fan 22, and the control circuit unit 4 for controlling the light source unit 3 to be lit on. The light source unit 3 and the control circuit unit 4 are arranged on both sides of the water cooling unit 5 across the water cooling jacket 20. One face of the control circuit unit 4 is put in close contact with the water cooling jacket 20, and the other face is provided with a radiation pin (a radiation portion) 17. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a water-cooled LED lighting apparatus that employs a method of forcibly cooling a light source unit and a control circuit unit with cooling water.

  In recent years, lighting devices such as vehicular headlamps and outdoor lighting lamps have been changed from those using a high-intensity lamp such as a xenon lamp or sodium lamp as a light source to those using a long-life and low-power consumption LED as a light source. Replacement is progressing, and higher output is desired for LED lighting devices using LEDs as light sources.

  By the way, currently popular xenon lamps have a large output of about 200 W to 2000 W, and the power input to the LED lighting device as a substitute for this tends to increase. Recently, the power input to one LED lighting device is increasing. The thing whose electric power exceeds 200W has been developed.

  Since the amount of heat generated by the LED light source unit increases as the power of the LED lighting device increases, a cooling structure for stably driving the temperature lower in the LED light source whose life and output change depending on the temperature. Has become an important development issue. As its cooling structure, for example, in Patent Document 1, the LED mounting substrate is pressed and fixed to a metal heat dissipation fixing plate by a metal heat dissipation cover, and the heat dissipation fixing plate to which the LED mounting substrate is fixed is referred to as a translucent cover. The structure which arrange | positions in the sealed space formed of the resin case, and forms a some heat radiating fin in the heat radiating fixed plate is proposed. In this configuration, heat generated by the LED light source is conducted to the heat radiating fixing plate via the LED mounting substrate, and also conducted to the heat radiating fixing plate via the heat radiating cover, and the heat conducted to the heat radiating fixing plate is radiated. The LED light source is cooled because it is diffused from the fins through the resin case to the atmosphere.

  Further, Patent Document 2 discloses an LED as a light source, a heat sink capable of air-cooling or cooling the LED, a light-emitting circuit that applies a current for causing the LED to emit light, and a water droplet that detects that the lighting device is in water. In a lighting device equipped with a sensor, when the water drop sensor detects that the lighting device is not in water, the light emitting circuit limits the current supplied to the LED to prevent overheating of the LED, and the lighting device is in water A configuration has been proposed in which a light emitting circuit supplies a high current to an LED to increase the light emission luminance of the LED.

JP 2002-299700 A JP 2003-047914 A

  However, the natural heat dissipation structure proposed in Patent Document 1 cannot be expected to have a high cooling effect, and there is a limit to cope with further higher output.

  Further, in the configuration proposed in Patent Document 2, a high current is supplied to the LED only when the lighting device is in water, and when the lighting device is not in water, it is necessary to rely on heat dissipation by natural cooling. However, there is a problem that a high current cannot be supplied to the LED.

  By the way, a control circuit unit for controlling the lighting of the light source unit is indispensable for the LED lighting device, and various electronic components provided in the control circuit unit also generate heat, thereby realizing high output of the LED lighting device. Therefore, it is necessary to cool the control circuit unit as well as the light source unit.

  The present invention has been made in view of the above problems, and the object of the process is to provide a water-cooled LED lighting device capable of realizing high output by forcibly cooling the light source unit and the control circuit unit with cooling water. It is to provide.

In order to achieve the above object, the invention according to claim 1
A housing;
A light source unit using an LED as a light source;
A water cooling unit comprising a water cooling jacket, a radiator, a circulation pump and a fan;
A control circuit unit for controlling the lighting of the light source unit;
In a water-cooled LED lighting device comprising:
The light source unit and the control circuit unit are arranged on both sides of a water cooling jacket of the water cooling unit.

  The invention according to claim 2 is characterized in that, in the invention according to claim 1, one surface of the control circuit unit is brought into close contact with the water cooling jacket, and a heat radiating portion is provided on the other surface.

  A third aspect of the invention is characterized in that, in the first or second aspect of the invention, the light source unit is in close contact with the water-cooling jacket through a heat conductive sheet.

  The invention according to claim 4 is the invention according to any one of claims 1 to 3, wherein a space is formed between the water cooling jacket and the radiator of the water cooling unit, and the control circuit unit is arranged in the space. It is characterized by that.

  According to the invention of claim 1, in the water cooling unit, the cooling water circulates in the closed loop by the circulation pump, and the light source unit and the control circuit unit arranged on both sides of the water cooling jacket are forcibly cooled by the cooling water. The temperature rise of the light source unit and the control circuit unit is suppressed, and high output of the water-cooled LED lighting device is realized. The cooling water that has received heat from the light source unit and the control circuit unit in the water cooling jacket is cooled by heat exchange with the outside air in the radiator, and then supplied to the water cooling jacket to cool the light source unit and the control circuit unit. In this way, the cooling water is repeatedly circulated in the closed loop and repeatedly cooled and radiated, whereby the light source unit and the control circuit unit are continuously forcibly cooled to suppress the temperature rise.

  According to the second aspect of the present invention, since one surface of the control circuit unit is brought into close contact with the water cooling jacket and the heat radiating portion is provided on the other surface, the control circuit is forcibly cooled by the cooling water and simultaneously from the heat radiating portion. Since the heat is dissipated, the control circuit unit is efficiently cooled and the temperature rise is more effectively suppressed.

  According to the invention of claim 3, since the entire surface of the light source unit is in close contact with the water cooling jacket via the heat conductive sheet having a high thermal conductivity, the entire surface of the light source unit becomes a heat transfer surface, and the light source unit is cooled by the cooling jacket. It is efficiently cooled by the cooling water flowing through. For this reason, it is difficult to bring the entire surface of the light source unit into close contact with the water cooling jacket without using a heat conductive sheet, and in fact the light source unit is only partially in contact with the water cooling jacket. It becomes impossible.

  According to the fourth aspect of the present invention, since the control circuit unit is arranged in the space formed between the water cooling jacket and the radiator of the water cooling unit, the cooling air introduced into the housing by the fan flows through the space. As a result, the control circuit unit is forcibly cooled by air, and the control circuit unit that is forcibly cooled by cooling water is further efficiently cooled, and the temperature rise is effectively suppressed.

1 is a perspective view of a water-cooled LED lighting device according to the present invention. It is a figure of the arrow A direction of FIG. It is a figure of the arrow B direction of FIG. It is CC sectional view taken on the line of FIG. It is the DD sectional view taken on the line of FIG. It is the EE sectional view taken on the line of FIG. 1 is an exploded perspective view of a water-cooled LED lighting device according to the present invention. It is a basic lineblock diagram of the water cooling unit of the water cooling type LED lighting device concerning the present invention. It is a figure which shows the relationship between the injection current to LED, and the output light beam value about the LED illuminating device using a water cooling system, and the LED illuminating device using a natural air cooling system. It is a perspective view of a heat sink. It is sectional drawing which shows the other form of the water-cooling type LED lighting apparatus which concerns on this invention.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  1 is a perspective view of a water-cooled LED lighting device according to the present invention, FIG. 2 is a view in the direction of arrow A in FIG. 1, FIG. 3 is a view in the direction of arrow B in FIG. FIG. 5 is a sectional view taken along the line DD of FIG. 3, FIG. 6 is a sectional view taken along the line EE of FIG. 3, FIG. 7 is an exploded perspective view of the water-cooled LED lighting device according to the present invention, and FIG. FIG. 2 is a basic configuration diagram of a water cooling unit of the water-cooled LED lighting device.

  As shown in FIGS. 4 to 7, the water-cooled LED lighting device 1 according to the present invention is configured by incorporating a light source unit 3, a control circuit unit 4, and a water-cooling unit 5 inside a rectangular box-shaped housing 2. . In addition, the upper and lower sides of the water-cooled LED lighting device 1 in the following description are in the state shown in FIG. 1, and the installation of the water-cooled LED lighting device 1 is not necessarily performed in the state shown in FIG.

  The housing 2 is made of a resin such as PC or a metal such as aluminum. As shown in FIG. 1, an air inlet 6 composed of a plurality of longitudinally long slits is formed on the peripheral surface of the housing 2. Is formed with an exhaust port 7 composed of a plurality of fan-shaped slits. The lower surface of the housing 2 is open, and the light source unit 3 is fitted and fixed in the opening.

  As shown in FIGS. 4 to 7, the light source unit 3 includes a plurality (9 in the illustrated example) of metal substrates 9 on which LEDs 8 (see FIG. 8) as light sources are mounted, and these metal substrates 9. A rectangular plate-like base 10 to be attached and a rectangular plate-like transparent resin lens 11 fitted into the lower surface opening of the housing 2 are included. In FIG. 7, reference numeral 12 denotes a cable connector.

  In the present embodiment, the nine metal substrates 9 on which the LEDs 8 are mounted are arranged in a matrix of three rows and columns, and correspondingly, the base 10 made of aluminum die-casting also has the same number of pedestals as the LEDs 8. 10a (refer to FIG. 4 and FIG. 6) is integrally projected in a matrix form of three rows. Each metal substrate 9 is fixed to each pedestal 10a of the base 10 with screws through a rectangular heat conductive sheet 13. In addition, each heat conductive sheet 13 is comprised with the silicon | silicone etc. with insulation and high heat conductivity.

  Further, as shown in FIG. 7, the control circuit unit 4 incorporates a circuit board 15 on which various electronic components (not shown) are mounted inside a rectangular box-shaped circuit case 14 whose bottom surface is open. The lower surface opening is covered with a rectangular plate-shaped cover 16. Here, the circuit case 14 is formed by aluminum die casting or the like having a high thermal conductivity, and a large number of heat radiation pins 17 constituting a heat radiation portion are integrally projected on the upper surface thereof. A circuit board 15 is in close contact with the inner upper surface of the circuit case 14 via a rectangular heat conductive sheet 18 made of silicon or the like having high insulation and thermal conductivity. Note that an O-ring 19 is interposed at the joint between the circuit case 14 and the cover 16, and the inside of the circuit case 14 is sealed by the sealing action of the O-ring 19, and water or the like from the outside into the circuit case 14. Intrusion is prevented.

  As shown in FIGS. 4 to 8, the water cooling unit 5 includes a water cooling jacket 20 that is a heat exchanger, and heat of the cooling water that has received heat in the water cooling jacket 20 and is heated to the outside air (cooling air). A radiator 21 for cooling by replacement, a fan 22 for supplying cooling air to the radiator 21, a circulation pump 23 for circulating the cooling water in a closed loop circulation path, and a reserve tank 24 for storing the cooling water. 22 is disposed above the radiator 21 so as to face it.

  By the way, the water cooling jacket 20 is formed in a hollow rectangular plate shape, and a cooling water passage is formed therein as shown in FIGS. As shown in FIGS. 5 and 7, an inlet pipe 25 into which cooling water cooled by heat exchange with the outside air (cooling air) in the radiator 21 flows on one end of the cooling jacket 10, and the water cooling An outlet pipe 26 is provided to discharge the cooling water whose temperature has been increased by receiving heat in the jacket 20.

  Thus, in the present embodiment, as shown in FIGS. 4 and 6, the water cooling jacket 20 is horizontally disposed at the bottom of the lower portion in the housing 2, and the water cooling jacket 20 is sandwiched and controlled up and down. A circuit unit 4 and a light source unit 3 are arranged. Here, the light source unit 3 disposed on the lower surface side of the water cooling jacket 20 has its base 10 in close contact with the lower surface of the water cooling jacket 20 via a rectangular heat conduction sheet 27. In the present embodiment, the heat conductive sheet 27 is made of silicon or the like having high insulation and thermal conductivity.

  The control circuit unit 4 is arranged on the upper surface side of the water cooling jacket 20 with the cover 16 being in close contact with the upper surface of the water cooling jacket 20. In this embodiment, an antifreeze liquid obtained by mixing water with propylene glycol is used as the cooling water.

  On the other hand, as shown in FIGS. 4 and 6, the radiator 21 and the fan 22 are disposed in the upper part of the housing 2 apart from the water cooling jacket 20, and a space portion is provided between the water cooling jacket 20 and the radiator 21. S is formed, and the control circuit unit 4, the circulation pump 23, and the reserve tank 24 are arranged in the space S. Specifically, a gate-shaped chassis 28 is erected on the water cooling jacket 20, and the control circuit unit 4 is disposed in a space surrounded by the chassis 28, and the circulation pump 23 and the reserve tank 24 are disposed on the chassis 28. Is installed.

  Here, as shown in FIGS. 5 and 8, a pipe (rubber hose) 29 rising upward from the outlet pipe 26 of the water cooling jacket 20 is connected to the inlet pipe 30 of the radiator 21, and from the outlet pipe 31 of the radiator 21. The extending pipe (rubber hose) 32 extends downward and is bent at a substantially right angle and connected to the suction side of the circulation pump 23. A pipe (rubber hose) 33 extending from the discharge side of the circulation pump 23 is connected to the inlet side of the reserve tank 24 as shown in FIG. 8, and a pipe (rubber hose) 34 extending downward from the outlet side of the reserve tank 24. Is connected to the inlet pipe 25 of the water cooling jacket 20. Thus, the water cooling jacket 20, the radiator 21, the circulation pump 23, and the reserve tank 24 are connected by the pipes (rubber hoses) 29, 32 to 34 to form a circulation path that forms an open loop. Circulation provides the required cooling action.

  Thus, when the water-cooled LED lighting device 1 configured as described above is activated and power is supplied to the light source unit 3, the control circuit unit 4, and the water-cooled unit 5, a plurality of light source units 3 (this embodiment) Nine LEDs 8 in the form emit light, and the light passes through the lens 11 and is irradiated downward in FIG. 1 to illuminate the front, but the lighting control of the light source unit 3 is controlled by the control circuit unit 4 During driving, the LED 8 of the light source unit 3 and various electronic components (not shown) of the control circuit unit 4 generate heat, and the light source unit 3 and the control circuit unit 4 are overheated and the temperature rises.

  However, in this embodiment, the water cooling unit 5 is driven simultaneously, and the light source unit 3 and the control circuit unit 4 are forcibly cooled by the cooling water circulating in the circulation path shown in FIG. It can be suppressed.

  That is, the cooling water circulating through the circulation path by the circulation pump 23 receives the heat generated in the light source unit 3 and the control circuit unit 4 in the water cooling jacket 20 to cool the light source unit 3 and the control circuit unit 4 and receive the heat. The cooling water whose temperature has been increased is introduced into the radiator 21 through the pipe 29.

  On the other hand, when the fan 22 is rotationally driven by a motor (not shown), the outside air is sucked from the side as the cooling air from the air inlet 6 formed in the peripheral surface of the housing 2, and this cooling air is supplied to the water cooling jacket. 20 flows upward through a space S formed between 20 and the radiator 21, passes through the radiator 21 in the process, and is discharged to the outside through the exhaust port 7 opened on the upper surface of the housing 2. In the radiator 21, the heat of the cooling water is radiated to the outside by the cooling air passing through the radiator 21 to cool the cooling water, and the cooling liquid water whose temperature has decreased is sucked into the circulation pump 23 through the pipe 32. Is done.

  The cooling water sucked into the circulation pump 23 is boosted and then sent out from the circulation pump 23 through the pipe 33 to the reserve tank 24, a part of which is stored in the reserve tank 24, and the remaining cooling water is stored in the reserve tank 24. Is introduced into the water-cooling jacket 20 through the pipe 34 and used for cooling the light source unit 3 and the control circuit unit 3. Then, the above action (cooling cycle) is continuously repeated, and the light source unit 3 and the control circuit unit 4 are forcibly cooled by the cooling water flowing through the water cooling jacket 20, and their temperature rise is suppressed to a certain value or less.

  Thus, in the present embodiment, since the control circuit unit 4 and the light source unit 3 are disposed above and below the water cooling jacket 20, the cooling water circulates in the closed loop circulation path by the circulation pump 23. The light source unit 3 and the control circuit unit 4 disposed on both sides of the jacket 20 are forcibly cooled simultaneously by the cooling water. As a result, the temperature rise of the light source unit 3 and the control circuit unit 4 is suppressed, and high output of the water-cooled LED lighting device 1 is realized.

  In the present embodiment, the lower surface of the control circuit unit 4 is brought into close contact with the water cooling jacket 20 and a large number of heat radiating pins 17 constituting the heat radiating portion are provided on the upper surface, so that the control circuit unit 4 is forcibly cooled by the cooling water. At the same time, since heat is naturally radiated from the heat radiating pins 17, the control circuit unit 4 is efficiently cooled, and the temperature rise is more effectively suppressed.

  Furthermore, in the present embodiment, the entire surface of the light source unit 3 is in close contact with the lower surface of the water-cooling jacket 20 via the heat conductive sheet 27 having a high thermal conductivity. The light source unit 3 is efficiently cooled by the cooling water flowing through the cooling jacket 20. For this reason, it is difficult to bring the entire surface of the light source unit 3 into close contact with the water cooling jacket 20 without using the heat conductive sheet 27. In fact, the light source unit 3 is only partially in contact with the water cooling jacket 20. It is impossible to increase efficiency. Alternatively, in order to bring the entire surface of the light source unit 3 into close contact with the water-cooling jacket 20 without using the heat conductive sheet 27, the joint surface of the metal water-cooling jacket 20 as well as the metal base 10 of the light source unit 3 is polished or the like. The finishing process may be performed smoothly, but such finishing process is not realistic because it requires a great number of man-hours, time and cost.

  In the present embodiment, since the control circuit unit 4 is arranged in the space S formed between the water cooling jacket 20 and the radiator 21 of the water cooling unit 5, the cooling air introduced into the housing 2 by the fan 22 is By flowing through the space S, the control circuit unit 4 is forcibly cooled by air, and the control circuit unit 4 that is forcibly cooled also by cooling water is cooled more efficiently, and the temperature rise can be effectively suppressed.

  Here, the relationship between the input current to the LED and the output light flux value was examined for the LED lighting device using the water cooling system and the LED lighting device using the natural air cooling system, such as the water-cooled LED lighting device 1 according to the present invention. The results are shown in FIG. The LED lighting device using the natural air cooling system uses the same light source unit 3 and base 10 as in the present embodiment, and uses an aluminum heat sink 20 ′ as shown in FIG. Also in this LED lighting device, the light source unit 3 was controlled to be turned on under the same conditions using the same control circuit unit 4 as in the embodiment. Note that the heat sink 20 ′ shown in FIG. 10 has a base portion 20A ′ having the same area as the water-cooling jacket 20 (the same area as the base 10) and a length of 30 mm from the base portion 20A ′ to the back surface (opposite the light source unit 3). A plurality of flat fins 20B ′ protruding by ˜50 mm were used.

From the results shown in FIG. 9, the LED lighting device using the natural cooling system has an input current of 0.5.
It can be seen that the output is drastically reduced at about A and that the output is reduced when driven by a current of 1 A or more. This is due to the temperature characteristics of LEDs (characteristics in which efficiency decreases as the temperature increases).

  On the other hand, in the LED lighting device using the water cooling system, even if it is driven with a current of 1 A or more, there is little decrease in output, and in this embodiment, it can be driven with a current more than twice that of natural air cooling, About twice the luminous flux could be obtained.

  Further, in the control circuit unit, 5% to 20% of the input power is lost as heat. Therefore, the greater the input power, the more the control circuit unit must be cooled. In this embodiment, about 20 W of heat is generated from the drive circuit unit 4. In order to operate the control circuit unit stably, the environmental temperature of the circuit components is desirably 80 ° C. or lower, and the size of the radiator is very large when natural heat dissipation is performed. For example, in the present embodiment, it is necessary to form the heat radiation pin 17 having a height of 35 mm or more in the circuit case 14.

  According to the water-cooled LED lighting device 1 according to the present invention using the water-cooling system, the control circuit unit 4 is also forcedly cooled by water cooling through the same cooling path as that of the light source unit 3, so that the heat dissipation structure with the control circuit unit 4 alone is provided. Is unnecessary, and a very compact design is possible.

  In the above embodiment, the radiator 21 and the fan 22 of the water cooling unit 5 are arranged in series in the vertical direction above the light source unit 3 and the control circuit unit 4 in the housing 2 and away from them. Although the height is increased, as shown in FIG. 11, if the configuration in which the radiator 21 and the fan 22 are juxtaposed next to the light source unit 3 and the control circuit unit 4 is adopted, the overall height can be kept low.

DESCRIPTION OF SYMBOLS 1 Water-cooled type LED lighting apparatus 2 Housing 3 Light source unit 4 Control circuit unit 5 Water-cooled unit 6 Intake port 7 Exhaust port 8 LED
DESCRIPTION OF SYMBOLS 9 Metal board 10 Base 10a Base 11 Lens 12 Cable connector 13 Thermal conduction sheet 14 Circuit case 15 Circuit board 16 Cover 17 Radiation pin 18 Thermal conduction sheet 19 O-ring 20 Water cooling jacket 21 Radiator 22 Fan 23 Circulation pump 24 Reserve tank 25 Water cooling jacket inlet pipe 26 Water cooling jacket outlet pipe 27 Heat conduction sheet 28 Chassis 29 Piping (rubber hose)
30 Radiator inlet pipe 31 Radiator outlet pipe 32-34 Piping (rubber hose)
S space

Claims (4)

A housing;
A light source unit using an LED as a light source;
A water cooling unit comprising a water cooling jacket, a radiator, a circulation pump and a fan;
A control circuit unit for controlling the lighting of the light source unit;
In a water-cooled LED lighting device comprising:
A water-cooled LED lighting device, wherein the light source unit and the control circuit unit are arranged on both sides of a water-cooling jacket of the water-cooling unit.   The water-cooled LED lighting device according to claim 1, wherein one surface of the control circuit unit is in close contact with the water-cooling jacket, and a heat radiating portion is provided on the other surface.   3. The water-cooled LED lighting device according to claim 1, wherein the light source unit and the control circuit unit are in close contact with the water-cooling jacket through a heat conductive sheet.   The water-cooled LED lighting device according to any one of claims 1 to 3, wherein a space is formed between a water-cooling jacket and a radiator of the water-cooling unit, and the control circuit unit is disposed in the space. .

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