JP2014203653A - Illumination device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve miniaturization of a housing while securing a heat radiation property necessary for an illumination device.SOLUTION: An illumination device 1 includes: a tabular base 3 having a semiconductor light-emitting element disposed on one surface 3b and a heat sink 8 disposed on the other surface of the base 3. The heat sink 8 has at least one tabular radiation fin 80A erected on the other surface of the base 3. Height h of the radiation fin 80A or 80B is set to be h when a heat radiation amount ratio q, which is a rate of change of the value calculated from {wh((T+T)/2-T)/(T-T)} with respect to height h, is saturated. Here: w is a width of the radiation fin ; Tis temperature (k) of a base end of the radiation fin 80A or 80B; Tis temperature (K) of a tip of the radiation fin 80A or 80B; and Tis an atmospheric temperature (K).

Description

  The present invention relates to a lighting device including a semiconductor light emitting element such as an LED (light emitting diode).

2. Description of the Related Art In recent years, lighting devices including semiconductor light emitting elements such as LEDs as light sources have been adopted.
As an example, as disclosed in Patent Document 1, a plurality of light emitting modules on which LEDs are mounted are disposed on the front surface of a module plate serving as a base, and light from the plurality of LEDs is respectively forward. There is a lighting device adapted to be emitted. In such an illuminating device, since the semiconductor light emitting element generates heat during driving, a heat dissipation structure using a heat sink is employed. Specifically, a heat sink provided with radiation fins is attached to the back side of the base, and a case is provided so as to cover the heat sink. These heat sinks and cases are formed of a material having high thermal conductivity.

  Some of such lighting devices are formed in the same external shape as an existing HID (High Intensity Discharge) lamp, and power is supplied through a base socket and a base. . As an alternative to high-intensity discharge lamps, they are used by attaching to the ceiling surface of gymnasiums, factories and warehouses. In attaching the lighting device, a method is used in which the case is supported by a support member or the like, and the support member is attached to a ceiling surface or the like.

JP2012-14900A

  In the illumination device as described above, it is desirable to efficiently dissipate the heat generated from the LEDs in order to extend the life. In particular, in high-intensity LED lighting devices used as an alternative to high-intensity discharge lamps such as mercury lamps and metal halide lamps for energy saving, heat generated from the LEDs can be efficiently radiated to the outside air around the lighting device by natural cooling. It becomes even more important. Therefore, in patent document 1, the structure which provided the radiation fin in the housing | casing of the illuminating device is taken. In a high-intensity LED lighting device, since the amount of heat to be dissipated is large, it is conceivable to adopt a heat dissipation structure having large heat dissipation fins. However, in that case, there is a concern about an increase in the size of the housing of the lighting device and an increase in material costs.

  An object of this invention is to provide the illuminating device which implement | achieves size reduction of a housing | casing, ensuring a required heat dissipation in such a background.

In order to solve the above problems, a lighting device according to one embodiment of the present invention includes a semiconductor light-emitting element, a plate-like base on which the semiconductor light-emitting element is arranged on one surface, and the other surface of the base A heat sink disposed above, the heat sink has at least one plate-shaped heat radiation fin erected on the other surface of the base, and the height h of the heat radiation fin is:
{Wh ^0.75 ((T _max + T _min ) / 2−T _a ) ^2.25 / (T _max −T _a )}
An illuminating device characterized in that the heat radiation amount ratio q, which is a rate of change of the value calculated with respect to the height h, is h when it is saturated as h increases.

However, w is the radiating fin width, T _max is the radiating fins of the base end temperature (K), the T _min is the temperature of the tip of the heat radiating fins (K), T _a is the ambient temperature (K).
In another aspect, there are a plurality of the radiating fins, and the height h of each radiating fin constituting the radiating fins is such that the radiating amount Q with increasing h is saturated with increasing h. The configuration may be h.

Here, “h when the rate of change in heat dissipation q is saturated as h increases” means that the rate of change in the ratio of heat dissipation q as the increase in h is 0.0005 / mm to 0.002 / mm H, and preferably h when it is about 0.001 / mm or less. The heat dissipation rate change rate q is defined as the rate of change of the heat dissipation amount Q with respect to the height h.
Further, in another aspect, further comprising a bottomed cylindrical case having an open end connected to the outer edge of the base in a state of surrounding the heat sink, the central region of the base includes a first 1 A plurality of radiating fins are erected, and a plurality of second fins are erected so as to surround the first radiating fin,
Height h ₁ of first radiating fin> Height h _{2 of} second radiating fin
The structure which is may be sufficient.

In another aspect, any one of the first heat dissipating fins may be disposed at a position overlapping the semiconductor light emitting element in plan view.
In another aspect, the bottom of the case and the base may each be provided with a vent hole that communicates the inside and outside of the case.
Moreover, the structure by which the ventilation hole of the said base was opened in the position adjacent to each said radiation fin in planar view may be sufficient as another aspect.

In another aspect, the vent of the case may be configured to be opened at a position overlapping with at least one of the radiating fins when the bottom portion is viewed in plan.
In another aspect, the base may have a structure in which the vent hole is opened at a position adjacent to the outer edge.
In another aspect, the base is disk-shaped, the case is cylindrical, the semiconductor light emitting element is arranged in a central region of the base, and the vent hole of the base is There may be a configuration in which a plurality of semiconductor light emitting elements are surrounded.

In another aspect, the semiconductor light emitting element is an LED, and further includes a substrate formed by mounting a plurality of the semiconductor light emitting elements on a surface of the substrate, and the substrate is bonded to the base, thereby The semiconductor light emitting element may be configured to be thermally coupled to the base via the substrate.
Further, in another aspect, a support pipe having one end connected to the base and penetrating the case, and an attachment portion connected to the other end of the support pipe and attached to the construction material The structure which has this may be sufficient.

  In the lighting device according to one embodiment of the present invention, the housing can be downsized with the above-described configuration while ensuring heat dissipation necessary for the high-luminance LED lighting device.

It is an external appearance block diagram of the illuminating device 1 which concerns on embodiment. It is the external appearance block diagram which looked at the illuminating device 1 from diagonally upward. FIG. 3 is an exploded view showing an internal configuration of the lighting device 1. It is sectional drawing which shows the internal structure which looked at the illuminating device 1 from diagonally upward. FIG. 3 is a schematic perspective view showing the module plate 3, the outer heat sink 8 </ b> A, the inner heat sink 8 </ b> B, and the support pipe 6 extracted from the configuration of the lighting device 1. FIG. 4 is a schematic plan view showing an arrangement form of the heat radiation fins 80A of the outer heat sink 8A and the heat radiation fins 80B of the inner heat sink 8B with respect to the module plate 3. It is a top view when the illuminating device 1 is cut | disconnected by the cross section AA in FIG. 2, and the case 2 is planarly viewed from the Y direction. It is sectional drawing for demonstrating the thermal radiation effect of the illuminating device. (A) is a schematic plan view which shows the shape of the radiation fin 80B, (b) is a schematic plan view which shows the arrangement | positioning form of the radiation fin 80B with respect to the module plate 3. FIG. It is a calculation result which shows the change of the thermal radiation amount Q from a radiation fin when the width w of the radiation fin 80B is fixed and the fin height h is changed. It is a calculation result which shows the change of the thermal radiation amount Q from a radiation fin when the width w of the radiation fin 80A is fixed and the fin height h is changed. It is a bottom view when the illuminating device which concerns on a modification is planarly viewed from the module plate side.

<< Embodiment 1 >>
Hereinafter, the illuminating device 1 concerning embodiment is demonstrated, referring drawings.
(Overall configuration of lighting device 1)
FIG. 1 is an external configuration diagram of a lighting device 1 according to an embodiment. FIG. 2 is an external configuration diagram of the illumination device 1 as viewed obliquely from above. FIG. 3 is an exploded view showing an internal configuration of the lighting device 1. FIG. 4 is a cross-sectional view showing an internal configuration of the lighting device 1 as viewed obliquely from above. 1-4, the direction shown by the arrow Y is the back, and the opposite direction is the front. In the illuminating device 1, light is mainly emitted forward. As shown in FIGS. 1 to 4, the lighting device 1 includes a module plate 3 that is a base, a plurality of light emitting modules 4 arranged on the front surface of the module plate 3, and a support pipe that extends rearward from the center of the module plate 3. 6 is provided.

In the lighting device 1, an inner heat sink 8 </ b> B and an outer heat sink 8 </ b> A are attached to the rear surface of the module plate 3.
The inner heat sink 8B has a plurality of heat radiation fins 80B, and the outer heat sink 8A also has a plurality of heat radiation fins 80A. Accordingly, a plurality of heat radiation fins 80B and 80A extending rearward from the module plate 3 are disposed so as to surround the periphery of the support pipe 6.

Furthermore, in the illuminating device 1, a case 2 that extends rearward from the outer edge of the module plate 3 and surrounds the inner heat sink 8B and the outer heat sink 8A is mounted.
A mounting portion 7, which is a member for mounting the support pipe 6 to a construction material (not shown), is attached to the rear end portion 6 b of the support pipe 6.
A cover 5 that covers the plurality of light emitting modules 4 is attached to the front surface of the module plate 3.

A wiring 90 for supplying power to the plurality of light emitting modules 4 is inserted into the support pipe 6.
As shown in FIG. 4, the lighting device 1 has a mounting portion 7 attached to a construction material (gymnasium, factory, warehouse ceiling, etc.) not shown, and is used as a lighting device instead of an HID lamp.
Each component of the illuminating device 1 is demonstrated below.

(Module plate 3)
The module plate 3 is a disk-shaped member made of a material having high thermal conductivity. Examples of the material having high thermal conductivity include metals such as aluminum and magnesium. A fitting hole 3 a is formed at the center of the module plate 3 to fit the front end 6 a of the support pipe 6.

On the front surface of the module plate 3, a module mounting region 3b for mounting a plurality of (six) light emitting modules 4 around the fitting hole 3a is secured, and a plurality of vent holes 3c are provided around the outer periphery of the module plate 3. Along the direction, they are arranged in an annular shape.
Each vent hole 3c is formed by cutting out the plate material of the module plate 3, and a bridge 3d is formed between the vent holes 3c.

  FIG. 6 is a bottom view of the lighting device 1 when viewed from the module plate 3 side. As shown in FIG. 6, the vent hole 3c of the module plate 3 is arranged at a position adjacent to the radiation fins 80A in plan view. Here, “arranged in an adjacent position” means that there is no obstacle between the vent hole 3c and the radiating fin 80A, and the intake air from the vent hole 3c can easily come into contact with the radiating fin 80A. I say something. The vent 3c allows outside air to flow inside the case 2 when the lighting device 1 is driven. The heat dissipation effect of the lighting device 1 will be described later.

The diameter of the module plate 3 is, for example, 260 mm, and the plate thickness is, for example, 1 to 5 mm.
(Light emitting module 4)
A plurality (six) of light emitting modules 4 are fixed in an annular shape in the module mounting region 3b. These light emitting modules 4 are arranged at an angle of 60 ° around the fitting hole 3a.

Each light emitting module 4 includes a substrate 40 and a light emitting unit 41 formed on the substrate 40.
The substrate 40 is made of, for example, a glass composite material, and a wiring pattern (not shown) for supplying power to the light emitting unit 41 is formed on the surface of the substrate 40.
The light emitting unit 41 includes a plurality of (for example, 132) COB (Chip on Board) type LEDs mounted on the substrate 40 and a sealing layer including a phosphor arranged to cover the LEDs. Has been. A part of the blue light emitted from the LED is converted into light having a relatively long wavelength by the phosphor and mixed with the blue light to emit white light.

Each light emitting module 4 is attached in a state where it is thermally coupled to the module attachment region 3 b of the module plate 3. The light emitting module 4 is fixed while pressed against the front surface of the module plate 3. Further, the heat generated from the light emitting module 4 is efficiently transferred to the module plate 3.
(Support pipe 6)
The support pipe 6 is a straight pipe made of a material having good heat conductivity. Examples of the material of the support pipe 6 include a metal such as stainless steel or a resin having good heat conductivity (a heat conductive resin obtained by mixing carbon or the like with a resin).

The front end portion 6 a of the support pipe 6 is fitted in the fitting hole 3 a and joined to the module plate 3. Specifically, the front end portion 6a of the support pipe 6 is inserted into the fitting hole 3a of the module plate 3, and the front end portion 6a is joined to the edge of the fitting hole 3a by caulking.
On the other hand, the rear end portion 6 b of the support pipe 6 is joined to the attachment portion 7 while being inserted into the insertion port 7 a of the attachment portion 7.

As described above, the support pipe 6 has a function of supporting the module plate 3 and serves as a passage for favorably conducting heat from the module plate 3 to the mounting portion 7. Further, the hollow portion inside the support pipe 6 is a passage through which the wiring 90 is inserted.
The length of the support pipe 6 is about the same as or higher than the height of the case 2, and is about 6 to 8 cm, for example.

The strength increases as the outer diameter and thickness of the support pipe 6 increase. In addition, the larger the outer diameter and the wall thickness, the larger the cross-sectional area, so that the heat transfer efficiency is improved and the temperature of the module plate 3 can be reduced. However, the weight increases. It may be determined within a range.
When the support pipe 6 is made of metal, for example, the outer diameter of the support pipe 6 is 27 mm and the wall thickness is about 1 to 3 mm.

(Heat sink 8)
FIG. 5 is a schematic perspective view showing the module plate 3, the outer heat sink 8 </ b> A, the inner heat sink 8 </ b> B, and the support pipe 6 extracted from the configuration of the lighting device 1. As shown in FIGS. 4 and 5, the heat sink 8 includes an inner heat sink 8 </ b> B and an outer heat sink 8 </ b> A, and is joined to the rear surface of the module plate 3.

The inner heat sink 8B includes a substantially annular support portion 81B that contacts the rear surface of the module plate 3 around the support pipe 6, and a plurality of heat radiation fins 80B that are folded back at the outer periphery of the support portion 81B and extend rearward. It is comprised. Each radiating fin 80B in the inner heat sink 8B has a strip shape having a height h _80B elongated in the extending direction and a width w _80B . The plurality of radiating fins 80 </ b> B surround the support pipe 6 and extend parallel to the support pipe 6.

The outer heat sink 8A includes an annular support portion 81A joined to the rear surface of the module plate 3 around the support portion 81B, and a plurality of heat radiation fins 80A extending rearward from the outer peripheral portion of the support portion 81A. ing. Each radiating fin 80A in the outer heat sink 8A has a strip shape having a height h _80A and a width w _80A elongated in the extending direction. The plurality of heat radiating fins 80 </ b> A surround the outside of the heat radiating fins 80 </ b> B and extend in parallel with the support pipe 6.

The heat sink 8 is disposed at a position overlapping the light emitting element in the light emitting portion of each light emitting module 4 along at least the thickness (Y) direction of the module plate 3. Thereby, the heat transfer path between the light emitting portion and the heat sink 8 can be shortened, and the drive heat of the light emitting element can be efficiently transferred to the heat sink 8 side.
FIG. 6 is a schematic plan view showing an arrangement of the heat radiation fins 80A of the outer heat sink 8A and the heat radiation fins 80B of the inner heat sink 8B with respect to the module plate 3. As shown in FIG. 6, the outer heat sink 8 </ b> A and the inner heat sink 8 </ b> B are arranged on the inner side of the outer peripheral region in the module plate 3 where the vent holes 3 c are opened. The heat radiating fins 80 </ b> A in the outer heat sink 8 </ b> A are formed in a region just inside the radial direction of the vent hole 3 c opened in the module plate 3. In other words, as shown in FIG. 6, the outer heat sink 8 </ b> A is arranged such that there is a gap 82 </ b> A between adjacent radiating fins 80 </ b> A at locations corresponding to the bridges 3 d of the module plate 3.

Furthermore, as shown in FIG. 6, each of the radiation fins 80 </ b> B and 80 </ b> A is inclined at a certain angle (for example, 45 °) with respect to the radial direction from the central axis of the support pipe 6 when viewed in plan from the Y direction. Yes.
Also in the inner heat sink 8B, a gap 82B is provided between adjacent radiating fins 80B, and the number of radiating fins 80B formed is the same as the number of radiating fins 80A formed in the outer heat sink 8A.

The inner heat sink 8B and the outer heat sink 8A are formed of a material having high thermal conductivity (for example, a metal such as aluminum), like the module plate 3. The support portion 81A and the support portion 81B are rivets or screws on the module plate 3. It is concluded with.
(Case 2)
As shown in FIGS. 1 to 4, the case 2 has a cylindrical tubular portion 2 d that extends rearward from the outer edge of the module plate 3, and a bottom portion 2 e that closes the rear portion of the tubular portion 2 d. The part 2d surrounds the outside of the radiation fin 80A. The front end portion 2a of the cylindrical portion 2d is opened, and the module plate 3 is attached thereto.

The cylindrical portion 61 and the module plate 3 are fixed by caulking the front end portion 2a of the cylindrical portion 2d to the outer edge portion 3e of the module plate 3.
A through hole 2f through which the support pipe 6 passes is formed at the center of the bottom 2e. The edge of the through hole 2 f in the bottom 2 e is joined to the support pipe 6.
For this joining, for example, a pipe clamp may be installed at the edge of the through hole 2f in the bottom 2e, and the pipe clamp may be fastened to the support pipe 6, or the edge of the through hole 2f and the support pipe may be bonded with an adhesive. 6 may be joined.

The case 2 is also formed of a heat conductive material (for example, a metal such as aluminum or magnesium, or a heat conductive resin obtained by mixing carbon with a resin).
A plurality of vent holes 2c are formed from the rear end side of the cylindrical portion 2d in the case 2 to the bottom portion 2e. Each air hole 2c is formed by forming a notch in the plate material of the case 2 and bending it inward. The ventilation hole 2c is a hole for releasing the air heated by the heat sink 8 inside the case 2 when the lighting device 1 is driven. Since the air hole 2c is formed by cutting and bending the member of the case 2 in an L shape inside, the horizontal portion of the L shape cutting and bending can reduce the falling of dust into the case 2.

  FIG. 7 is a top view when the illumination device 1 is cut along a cross section AA in FIG. 2 and the case 2 is viewed in plan view from the Y direction. As shown in FIG. 5, in the lighting device 1, the ventilation hole 2 c has a part of a cross section of at least one of the heat radiation fins 80 </ b> A and 80 </ b> B of the heat sink 8 when the bottom 2 e of the case 2 is viewed from the Y direction. Radially opened at overlapping positions in the Y direction. The case 2 may be formed with other air holes in addition to the air holes 2c.

In addition, a plurality of beads 2b are formed in the cylindrical portion 2d at regular intervals by pressing, thereby increasing the strength of the cylindrical portion 61.
The diameter of the front end 2 a of the case 2 is equal to the diameter of the module plate 3. The height of the case 2 in the Y direction is, for example, 270 mm, and the plate thickness is, for example, 1 mm.
The positional relationship between the radiating fin 80A and the case 2 will be described. As shown in FIG. 6, a certain distance is provided between the radiation fin 80 </ b> A and the case 2. In this embodiment, it is 10 mm as an example. Thus, direct contact between the heat sink 8 and the case 2 is avoided.

(Mounting part 7)
The attachment portion 7 has a function of fixing the rear end portion 32 of the support pipe 6 to a construction material such as a ceiling. As shown in FIGS. 1 to 4, the mounting portion 7 includes a pedestal portion 7 c having a frustoconical outer shape whose diameter increases rearward, and a rear end portion 6 b of the support pipe 6 provided on the front end side of the pedestal portion 7 c. And a flange portion 7d provided on the rear end side of the base portion 7c.

And the rear-end part 6b of the support pipe 6 is inserted and fixed to the insertion port 7a. This fixing is performed by, for example, a method of fastening with a screw that penetrates the insertion port 7a and the support pipe 6, or a method of bonding with an adhesive.
The mounting portion 7 is also formed of a heat conductive material like the support pipe 6.
Here, since the internal space of the insertion port 7a communicates with the internal space of the pedestal portion 7c, the internal space of the support pipe 6 inserted into the insertion port 7a and the internal space of the pedestal portion 7c also communicate with each other.

A plurality of insertion holes 7b are formed in the flange portion 7d. When fixing the attachment portion 7 to the construction material by screwing, the flange portion 7d is fixed to the construction material by inserting a screw into the insertion hole 7b and screwing it into the construction material.
(Cover 5)
The cover 5 is mounted so as to cover the plurality of light emitting modules 4 arranged on the front surface of the module plate 3 as a whole.

The cover 5 has a Fresnel lens structure, collects light emitted from the plurality of light emitting modules 4 and emits the light forward.
The cover 5 is formed by injection-molding a transparent resin material such as acrylic resin, polyethylene terephthalate, or polycarbonate.
The cover 5 is fixed to the front surface of the module plate 3 by bonding or screwing.

(Wiring 90 for power supply)
The power supply wiring 90 extends from the power supply unit (not shown) to the fitting hole 3a of the module plate 3 through the through hole of the construction material, the internal space of the mounting portion 7, and the internal space of the support pipe 6. Yes. A lead wire is branched from each wiring 90, and the tip of the branched lead wire is electrically connected to the light emitting module 4.

The wiring 90 and the lead wire are heat resistant wires, and for example, a crosslinked polyethylene insulated wire, a silicone rubber insulated wire, a fluororesin insulated wire, a silicone glass heat resistant wire, or the like is used.
Power is supplied from the power supply unit to each of the light emitting modules 4 through the power supply wiring 90 and lead wires.

The power consumption in each light emitting module 4 is 30 W, for example.
When each light emitting module 4 is driven, the LED emits light, and the light emitted from the light emitting unit 41 passes through the cover 5 and is emitted in front of the illumination device 1.
(About operation | movement of the illuminating device 1)
When using the lighting device 1, the user operates the power supply device to turn on the lighting device 1. Thereby, the light emitting part of each light emitting module 4 emits light. The emitted light is condensed when passing through the Fresnel lens structure of the cover 5 and is irradiated outside as illumination light. The driving heat of each light emitting module 4 is transferred to the heat sink 8 inside the case 2 through the module plate 3.

  Here, the inside of the lighting device 1 being driven is shown. FIG. 8 is a cross-sectional view for explaining the heat dissipation effect of the lighting device 1. In the illuminating device 1, outside air passes through the inside of the case 2 through the ventilation holes 3 c of the module plate 3. The outside air exchanges heat with the heat sink 8 by coming into contact with the heat radiating fins 80A of the heat sink 8 adjacent to the vent hole 3c inside the case 2. As a result, the heated outside air rises along the radiation fins 80A and is radiated to the outside of the case 2 through the vent holes 2c that exist directly above the radiation fins 80A. As described above, by arranging the air holes 3c at positions adjacent to the heat radiating fins 80A, while ensuring a heat transfer path from the module plate 3 to the heat radiating fins 80A, the outside air from the air holes 3c is efficiently radiated from the heat radiating fins 80A. Can be contacted.

  The outside air that has entered the case 2 through the ventilation holes 3c of the module plate 3 passes through the gaps 82A between the heat radiation fins 80A and the heat radiation fins 80A, wraps around the back side of the heat radiation fins 80A, and comes into contact with the heat radiation fins 80B. The outside air is heat exchanged with the heat sink 8. As a result, the heated outside air rises along the radiation fins 80B, and is radiated to the outside of the case 2 through the air holes 2c that exist directly above the radiation fins 80B. Thus, since air always flows upward in the case 2, the heat of the heat sink 8 can be efficiently dissipated to the outside air, and excellent heat dissipation characteristics can be realized.

  Further, as shown in FIG. 1, when any surface of the module plate 3 is viewed in plan, the position of the vent hole 3c is the position where the module plate 3 and the case 2 are connected (the position corresponding to the outer edge 3e). It exists in an adjacent position. With such a configuration, the cooling effect by the outside air flowing through the vent hole 3c is obtained, and the driving heat of each light emitting module 4 is not easily transferred to the case 2 through the outer edge portion 3e outside the vent hole 3c. Therefore, while preventing the case 2 from being heated excessively, as described above, the heat of the heat sink 8 can be efficiently radiated through the radiating fins 80A and the radiating fins 80B, and excellent heat dissipation characteristics can be realized.

(Relationship between heat sink surface area and heat dissipation characteristics)
The calculation was performed on the relationship between the surface area of the heat radiation fins 80A and 80B and the heat radiation characteristics. FIG. 9A is a schematic plan view showing the shape of the radiation fin 80A used for the calculation, and FIG. 9B is a schematic plan view showing the arrangement of the radiation fin 80A with respect to the module plate 3. As shown in FIG. 9A, one radiating fin 80A having a width w and a height h was used. The radiation fins 80A were formed using an aluminum plate having a thickness of 1.5 mm. As shown in FIG. 7B, when a virtual straight line L ₁ passing through the center Ax ₃ of the module plate 3 and the center in the width direction of the radiation fin 80A is drawn, the virtual straight line L ₁ and the main surface of the radiation fin 80A The fin angle (crossing angle) θ formed by is set to 45 °. The radiating fin 80B (not shown) is located on the inner peripheral side of the radiating fin 80A. Also for the radiation fin 80B, a single aluminum plate having a width w, a height h, and a plate thickness of 1.5 mm is used, and the fin angle (intersection angle) θ between the virtual straight line L ₁ and the main surface of the radiation fin 80B is The angle was 45 °.

[a formula]
Generally, the heat flow by natural convection is expressed by the following equation using the heat transfer coefficient.
Heat flow rate (W) =
Heat transfer coefficient (W / m ² K) x object surface area (m ² ) x (surface temperature-fluid temperature) (K)
... (1)
And in the flat plate-shaped radiation fin which set | placed vertically using air as a refrigerant | coolant, a heat transfer rate is represented by the following formula | equation.

Heat transfer coefficient (W / m ² K) = k (temperature difference (K) / radiation fin height (m)) ^0.25
... (2)
Here, k is a coefficient, and can be set to, for example, about 1.4 in the case of a flat plate-like radiating fin using air as a refrigerant.
From this, the heat radiation amount Q from the radiation fins 80A or 80B in the lighting device 1 can be expressed by the following equation.

Q = kwh (T _mean −T _a ) ^1.25 η / h ^0.25 (3)
here,
w is the width of the heat radiating fin, and when it is not constant in the height direction, it indicates the average value over the entire area in the height direction. h is the height of the fin, and when it is not constant in the width direction, it indicates the average value over the entire width direction.

T _mean (K) is an average value of the surface temperatures of the radiating fins, and is calculated as an average value of the maximum temperature T _max and the minimum temperature T _min of the radiating fins. The maximum temperature T _max can be measured as the base end temperature of the radiating fin, and the minimum temperature T _min can be measured as the tip temperature of the radiating fin.
T _a (K) is the temperature of the atmosphere in which the radiation fins are placed. It is the temperature at a position sufficiently away from the radiating fin, and can be measured, for example, at a position about 1 m away.

η is the fin efficiency,
η = (T _mean −T _a ) / (T _max −T _a ) (4)
It is prescribed by.
The heat release amount Q is defined by the following equation using the equations (3) and (4).
Q = k (wh ^0.75 ((T _max + T _min ) / 2−T _a ) ^2.25 / (T _max −T _a ))
(5)
However, k is a coefficient.

(Relationship between heat radiation fin 80B height and heat radiation characteristics)
The relationship between the height of the heat radiation fin 80B and the heat radiation characteristics was calculated. In the calculation, first, the lighting device 1 including the radiation fin 80B having a width w = 24 mm and a height h = 40 mm is created, and the base end temperature T _max (K) of the radiation fin and the tip temperature T _min ( K) and the atmospheric temperature T _a (K) were measured experimentally. Then, when varying the height h from 40mm to 360 mm, it was determined by calculating the tip temperature T _min of the heat radiating fins. T _min was determined based on the condition that the difference between the tip end temperature T _min and the base end temperature T _max of the radiating fin is proportional to the fin height h. Further, the base end temperature T _max, and atmosphere temperature T _a when each fin height h, the height h is using measured values when the 40 mm.

[Calculation result]
FIG. 10 is a calculation result showing a change in the heat radiation amount Q from the radiation fin when the width w of the radiation fin 80B is fixed and the fin height h is changed. FIG. 10 is a calculation showing the change in the heat dissipation amount Q from the heat dissipation fin 80B when the fin height h is changed from 40 mm to 360 mm as the heat dissipation amount ratio q to the heat dissipation amount when the fin height h is 40 mm. It is a result.

As shown in FIG. 10, the heat dissipation rate ratio q from the heat radiating fin when the fin height h is changed increases as the fin height h increases, but saturates at about 270 mm, and thereafter the fin height It can be seen that the heat dissipation rate ratio q does not increase even if h is increased.
The reason for this can be considered as follows. That is, the temperature of the radiating fin 80B is highest at the fin base end and lowest at the fin tip. On the other hand, the air heated by the heat transfer from the radiation fins 80B rises along the radiation fins 80B by buoyancy. At that time, the air further receives heat transfer from the heat radiating fins 80B that are in contact with the air, and the temperature rises to form a temperature boundary layer in which the warmed air layer becomes thicker as it goes downstream. Therefore, the temperature of the air in contact with the heat radiating fin 80B is highest near the fin tip.

  As shown in FIG. 10, when the fin height h is increased, the temperature of the air in the vicinity of the fin tip increases as the fin height h increases in the range of the fin height h from 40 mm to 270 mm. It is done. When the fin height h is 270 mm, the tip temperature of the fin and the temperature of the air near the tip of the fin are substantially equivalent, and even if the fin height is increased beyond 270 mm, the fin portion exceeding 270 mm is transferred to the air. It is considered that heat transfer is not performed.

As described above, as shown in FIG. 10, in the lighting device 1, by setting the height h of the heat radiation fin 80B to about 270 mm, it is possible to prevent excessive enlargement of the heat radiation fin while ensuring necessary heat dissipation. it can.
(Relationship between heat dissipation fin 80A height and heat dissipation characteristics)
The relationship between the height of the heat radiation fin 80A and the heat radiation characteristics was calculated. In the calculation, the lighting device 1 including the radiation fin 80A having the width w = 15 mm and the height h = 120 mm is created, and the base end temperature T _max (K) of the heat dissipation fin and the front end temperature T _min (K) of the heat dissipation fin. The ambient temperature T _a (K) was measured experimentally. Then, when the height h was changed from 40mm to 360 mm, it was determined by calculating the tip temperature T _min of the heat radiating fins. Further, the base end temperature T _max, and atmosphere temperature T _a when each fin height h, the height h is using measured values when the 40 mm.

FIG. 11 is a calculation result showing a change in the heat radiation amount Q from the radiation fin when the width w of the radiation fin 80A is fixed and the fin height h is changed. FIG. 11 is a calculation showing the change in the amount of heat radiation Q from the heat radiation fin 80A when the fin height h is changed from 40 mm to 360 mm as a heat radiation amount ratio q to the heat radiation amount when the fin height h is 120 mm. It is a result.
As shown in FIG. 11, the heat dissipation amount ratio q from the radiation fin when the fin height h is changed increases as the fin height h increases from about 40 mm to h, but saturates at about 120 mm, and thereafter It can be seen that even if the fin height h is increased, the heat dissipation rate q does not increase. Thus, in the lighting device 1, by setting the height h of the heat radiating fins 80A to about 120 mm, it is possible to prevent excessive enlargement of the heat radiating fins while ensuring necessary heat dissipation.

(Brief Summary)
The lighting device 1 includes a plate-shaped module plate 3 in which a semiconductor light emitting element is disposed on one surface, and a heat sink 8 disposed on the other surface of the module plate 3. The at least one plate-like heat radiation fin 80A or 80B is erected on the other surface, and the height of the heat radiation fin 80A or 80B is the height h of the heat radiation amount Q calculated by the equation (3). The heat radiation amount ratio q defined as the rate of change with respect to the height h is set to the height h when it is saturated as the height h increases. For example, if the heat dissipation amount is Q ₀ when the predetermined height is h ₀ and the heat dissipation amount is Q ′ when the height is changed to h ′, the heat dissipation ratio q is defined as Q ′ / Q _0. Is done. That is, the height h of the radiating fin 80A is the rate of change with respect to the height h of the value calculated from {wh ^0.75 ((T _max + T _min ) / 2−T _a ) ^2.25 / (T _max −T _a )}. It is characterized in that a certain heat dissipation amount ratio q is h when it is saturated as h increases. Where w is the width of the radiating fin, T _max is the base temperature (K) of the radiating fin 80A or 80B, T _min is the temperature (K) of the tip of the radiating fin 80A or 80B, and T _max is the ambient temperature (K). is there.

With this configuration, the heat dissipation fin 80A can be prevented from being excessively enlarged and the case 2 can be reduced in size while ensuring the necessary heat dissipation Q.
When the heat sink 8 has a plurality of plate-like heat radiation fins 80A and 80B erected on the rear surface of the module plate 3, the height and width of each heat radiation fin constituting the plurality of heat radiation fins 80A and 80B are: (3) It was set as the structure each set to h when Q calculated by Formula is saturated. With this configuration, the heat dissipation fins 80A and 80B can each have the necessary heat dissipation Q, while preventing the heat dissipation fins 80A and 80B from being excessively large, and the case 2 can be downsized.

  In the above embodiment, the heat sink 8 is configured such that the heat sink 8A and the heat sink fin 80B provided with the plate-like heat sink fins 80A provided upright on the rear surface of the module plate 3 are composed of the heat sink 8B. However, the configuration of the radiating fins is not limited to the above and can be changed as appropriate. For example, in addition to the heat sink 8, another heat sink in which a plurality of strip-shaped heat radiation fins are erected on the outer peripheral side of the heat radiation fin 80 </ b> A so as to surround the heat radiation fin 80 </ b> A may be provided. Further, in addition to the heat sink 8, another heat sink in which a plurality of strip-shaped heat radiation fins are erected on the inner peripheral side of the heat radiation fin 80 </ b> B so as to surround the indicator pipe 6 may be provided.

Further, instead of the heat sink 8 in which the radiating fins 80A and 80B are concentrically arranged, a plurality of plate-like radiating fins may be arranged in different shapes on the rear surface of the module plate 3 and may be erected.
<Modification 1>
In the lighting device 1 according to the first embodiment described above, the vent 3c is located adjacent to the outer edge 3e, which is a connection position between the module plate 3 and the case 2, when any surface of the module plate 3 is viewed in plan. The structure is open. However, the vent hole 3c only needs to be opened at a position adjacent to the heat dissipating fins 80A and 80B in plan view, and can be modified as follows. FIG. 12 is a bottom view when the illumination device according to the modification is viewed from the module plate 3 side.

  12A is different in that the air holes 3c2 are formed at positions sandwiched between the heat radiation fins 80A and 80B in the radial direction of the module plate 31. With this configuration, the outside air that has entered the inside of the case 2 through the vent hole 3c2 can be brought into direct contact with both the radiation fins 80A and the radiation fins 80B, so that the outside air can more effectively exchange heat with the heat sink 8. Can do.

  12 (b), in addition to the vent hole 3c of the first embodiment, an opening 5c1 is provided in the center of the cover 51, and the vent hole 3c3 is more central than the heat radiation fin 80B in the radial direction of the module plate 32. It differs in that it is formed on the side. With this configuration, in addition to the introduction of the outside air from the vent hole 3c, the outside air that has entered the inside of the case 2 can be brought into direct contact with the heat radiating fins 80B via the vent hole 3c3. Heat exchange can be performed.

In the embodiment shown in FIG. 12C, the opening 5 c 2 is provided in the center of the cover 52. Further, a ventilation hole 3c4 adjacent to the outer edge 3e2 which is a connection position with the case 2, a ventilation hole 3c5 sandwiched between the radiation fins 80A and 80B in the radial direction, and a ventilation hole 3c6 located on the center side of the radiation fin 80B. The difference is that the module plate 33 is provided. With this configuration, the outside air that has entered the inside of the case 2 through the vent hole 3c3 can be brought into direct contact with the heat radiating fins 80A. In addition, the outside air that has entered through the vent 3c5 can be brought into direct contact with both the radiation fins 80A and the radiation fins 80B. Furthermore, the outside air that has entered through the vent 3c6 can be brought into direct contact with the radiation fin 80B. Therefore, the outside air can be more effectively exchanged heat with the heat sink 8 << Embodiment 2 >>
In the above embodiment, the hanging type illumination device is shown. However, the lighting device of the present invention is not limited to this type. For example, a lighting device such as a desk stand type, a ceiling type, or a downlight type may be used.

The light emitting element used in the present invention is not limited to the LED element. As the light emitting element of the present invention, other light emitting elements can be used. For example, a fluorescent lamp, an incandescent lamp, an organic EL (Electro-Luminescence) element, an LD (Laser Diode), or the like may be used alone or in combination.
Although the module plate 3 has a disc shape, the present invention is not limited to this. For example, it may be any one of a rectangular shape, a polygonal shape, and an elliptical shape. A plurality of module plates 3 can also be used.

The number of light emitting modules is not limited to six, and may be other numbers. Further, the arrangement of the light emitting modules on the module plate 3 is not limited to the circumferential shape, and may be rectangular or radial.
≪Other matters≫
As described above, the lighting device 1 is installed with the attachment portion 7 directly attached to a construction material such as a ceiling, and emits light by being supplied with DC power from an external power supply device. For this reason, since it is not necessary to install the illuminating device 1 with respect to the existing base socket, there is no possibility that the illuminating device 1 is erroneously connected so as to supply AC power via the base socket by mistake.
≪Summary≫
As described above, the lighting device 1 according to the present embodiment includes the plate-like base 3 on which the semiconductor light emitting element is arranged on one surface, and the heat sink 8 disposed on the other surface of the base 3. The heat sink 8 has at least one plate-like heat radiation fin 80A or 80B erected on the other surface of the base 3, and the height h of the heat radiation fin 80A or 80B is:
{Wh ^0.75 ((T _max + T _min ) / 2−T _a ) ^2.25 / (T _max −T _a )}
The heat release rate ratio q, which is the rate of change of the calculated value with respect to the height h, is h when it is saturated as h increases. Where w is the width of the radiating fin, T _max is the base temperature (K) of the radiating fin 80A or 80B, T _min is the temperature (K) of the tip of the radiating fin 80A or 80B, and T _max is the ambient temperature (K). is there.

With this configuration, it is possible to reduce the size of the case 2 while ensuring the heat dissipation necessary for the high-luminance lighting device.
In another aspect, the plurality of heat radiation fins 80A and 80B are plural, and the height of each heat radiation fin constituting the plurality of heat radiation fins 80A and 80B is such that the heat radiation amount Q is saturated as h increases. The configuration may be h.

With this configuration, it is possible to prevent the heat sink fins from being excessively large and to reduce the size of the case 2 while ensuring the necessary heat dissipation Q in the plurality of heat sink fins 80A and 80B.
Moreover, in another aspect, in the state which surrounds the heat sink 8, the bottomed cylindrical case 2 with which the opening edge part 2a was connected with respect to the outer edge part 3e of the base 3 is further provided, and the center area | region 3b of the base 3 is provided. The plurality of first radiating fins 80B are erected, and the plurality of second radiating fins 80A are erected so as to surround the first radiating fins. The height h ₁ of the first radiating fins 80B> the second radiating fins. The configuration may be a height h ₂ of 80A.

With this configuration, the heat dissipation fins 80A and 80B can each have the necessary heat dissipation Q, while preventing the heat dissipation fins 80A and 80B from being excessively large, and the case 2 can be downsized.
Moreover, in another aspect, either of the radiation fins 80A and 80B may be configured to be disposed at a position overlapping the semiconductor light emitting element in plan view.

With this configuration, the heat from the semiconductor light emitting element is more efficiently transferred to the radiation fins 80A and 80B.
In another aspect, the bottom 2e of the case 2 and the base 3 may each be provided with vent holes 2c and 3c communicating with the inside and outside of the case 2. With this configuration, outside air can be circulated into and out of the case 2 through the vent holes 3c and 2c provided in the module plate 3 and the case 2, respectively.

Further, in another aspect, the vent hole 3c of the base 3 may be configured to be opened at a position adjacent to the radiation fins 80A and 80B in plan view. With this configuration, the outside air from the vent hole 3 c can come into contact with the radiation fins 80 </ b> A of the heat sink 8 adjacent to the vent hole 3 c inside the case 2, and heat exchange with the heat sink 8 is effectively performed.
Further, in another aspect, the vent 2c of the case 2 may be configured to be opened at a position overlapping with at least one of the radiating fins 80A and 80B when the bottom 2e is viewed in plan.

With this configuration, the heat of the heat sink 8 can be efficiently radiated to the outside air, and the driving heat of the light emitting module 4 can be effectively radiated to the outside air around the lighting device 1.
In another aspect, the vent 3c of the base 3 may be open at a position adjacent to the outer edge 3e. With this configuration, the cooling effect by the outside air flowing through the vent hole 3c is obtained, and the driving heat of each light emitting module 4 is not easily transferred to the case 2 through the outer edge portion 3e outside the vent hole 3c. Therefore, while preventing the case 2 from being heated excessively, as described above, the heat of the heat sink 8 can be efficiently radiated through the radiating fins 80A and the radiating fins 80B, and excellent heat dissipation characteristics can be realized.

In another aspect, the base 3 is disk-shaped, the case 2 is cylindrical, and the semiconductor light emitting element is disposed in the central region 3b on one surface of the base 3, and the vent hole of the base A plurality of 3c exist so as to surround the semiconductor light emitting element.
The semiconductor light emitting element is an LED, and further includes a substrate 40 formed by mounting a plurality of semiconductor light emitting elements on the surface of the substrate 40, and the substrate 40 is bonded to the base 3, whereby each semiconductor light emitting element is connected to the substrate 40. It is thermally coupled to the base 3 via

Furthermore, the structure which has the support pipe 6 arrange | positioned so that one end may be connected with the base 3 and may penetrate the case 2, and the attachment part 7 connected with the other end of the support pipe 6 and attached with respect to a construction material It may be.
With this configuration, in addition to the above-described effects, heat from the lighting device 1 can be transmitted through the support pipe 6 and radiated to the construction material.

DESCRIPTION OF SYMBOLS 1 Illuminating device 2 Case 2c Vent hole 2e Bottom part 3 Module plate (base)
3b Main surface portion 3c Ventilation hole 3e Outer edge portion 4 Light emitting module 5 Cover 6 Support pipe 7 Mounting portion 8 Heat sink 8A Outer heat sink 8B Inner heat sink 80A, 80B Radiation fin

Claims (11)

A semiconductor light emitting device;
A plate-like base on which the semiconductor light emitting element is arranged on one surface;
A heat sink disposed on the other surface of the base,
The heat sink has at least one plate-like heat radiation fin erected on the other surface of the base,
The height h of the heat dissipating fin is:
{Wh ^0.75 ((T _max + T _min ) / 2−T _a ) ^2.25 / (T _max −T _a )}
A lighting device, characterized in that a heat dissipation amount ratio q, which is a rate of change of a value calculated with respect to the height h, is the height h when it is saturated as the height h increases.
However, w is the radiating fin width, T _max is the radiating fins of the base end temperature (K), T _min is the radiating fin tip temperature (K), T _a is the ambient temperature (K) There are a plurality of the heat radiating fins, and the height h of each of the radiating fins constituting the plurality of radiating fins is when the heat radiation amount ratio q with the increase in the height h is saturated with the increase in the height h. The lighting device according to claim 1, wherein the lighting device has a height h. In a state of surrounding the heat sink, it further comprises a bottomed cylindrical case with an open end connected to the outer edge of the base,
In the central region of the base, a plurality of first radiating fins are erected, and a plurality of second fins are erected so as to surround the first radiating fins,
Height h ₁ of first radiating fin> Height h _{2 of} second radiating fin
The lighting device according to claim 1, wherein the lighting device is a lighting device. 4. The lighting device according to claim 3, wherein any one of the first heat radiation fins is disposed at a position overlapping the semiconductor light emitting element in a plan view. Each of the bottom of the case and the base has a vent hole communicating with the inside and outside of the case.
The illuminating device according to claim 1, wherein: The lighting device according to claim 5, wherein the vent hole of the base is opened at a position adjacent to each of the radiation fins in a plan view. The lighting device according to claim 5, wherein the ventilation hole of the case is opened at a position overlapping with at least one of the heat dissipating fins when the bottom portion is viewed in plan. The lighting device according to claim 5, wherein the vent hole of the base is opened at a position adjacent to the outer edge portion. The base is disk-shaped,
The case is cylindrical,
The semiconductor light emitting device is disposed in a central region of the base,
The lighting device according to claim 1, wherein there are a plurality of vent holes in the base so as to surround the semiconductor light emitting element. The semiconductor light emitting element is an LED,
Further comprising a substrate formed by mounting a plurality of the semiconductor light emitting elements on the surface of the substrate,
The lighting device according to claim 1, wherein each of the semiconductor light emitting elements is thermally coupled to the base via the substrate by bonding the substrate to the base. A support pipe having one end connected to the base and penetrating the case;
The lighting device according to any one of claims 1 to 10, further comprising an attachment portion connected to the other end of the support pipe and attached to the construction material.

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